Arsenic(As)pollution seriously threatens human and ecological health.Microalgal cell wall and extracellular polymeric substances(EPS)are known to interactwith As,but their roles in the As resistance,accumulation and s...Arsenic(As)pollution seriously threatens human and ecological health.Microalgal cell wall and extracellular polymeric substances(EPS)are known to interactwith As,but their roles in the As resistance,accumulation and speciation inmicroalgae remain unclear.Here,we used two strains of Chlamydomonas reinhardtii,namely CC-125(wild type)and CC-503(cell walldeficientmutant),to examine the algal growth,EPS synthesis,As adsorption,absorption and transformation under 10–1000μg/L As(III)and As(V)treatments for 96 h.In both strains,the As absorption increased after the EPS removal,but the growth,As adsorption,and transformation of C.reinhardtii declined.The CC-125 strain was more tolerant to As stress and more efficient in EPS production,As accumulation,and redox transformation than CC-503,irrespective of EPS presence or absence.Three-dimension excitation-emission matrix(3DEEM)and attenuated total reflectance infrared spectroscopy(ATR-IR)analyses showed that As was bound with functional groups in the EPS and cell wall,such as-COOH,NH and-OH in proteins,polysaccharides and amino acids.Together,this study demonstrated that EPS and cell wall acted as barriers to lower the As uptake by C.reinhardtii.However,the cell wall mutant strain wasmore susceptible to As toxicity due to lower EPS induction and higher As absorption.展开更多
Black soil is essential for maintaining regional food security and promoting global agricultural production.Understanding the weathering process of parent material and the accumulation of organic carbon is crucial to ...Black soil is essential for maintaining regional food security and promoting global agricultural production.Understanding the weathering process of parent material and the accumulation of organic carbon is crucial to comprehending the developmental history and future trends of black soil,especially against the background of large-scale global cultivation and climate change.Although the importance of black soil formation and evolution cannot be ignored,the relevant research is still very scarce.In this study,a typical eight-meter-deep soil core was collected from the Keshan area of the Songnen Plain,Northeast China,where surface black soil developed on paleo-sediments.Using^(14)C dating,the formation age of the black soil was determined.Based on the characteristics of the geochemical composition,grain size and the magnetic susceptibility of the sediments,it was demonstrated that the black soil and its parent material originated from reworked loess.Furthermore,the mass transfer coefficient(τ)of some elements was determined,in order to explore the soil weathering process.By calculating the transported amount of alkaline and alkaline-earth elements,the weathering rate of parent material to black soil was found to be weak,at 0.16 kEq·ha^(-1)·year^(-1).Combining the results of dating and carbon density in the different layers of black soil,the accumulation rate of organic carbon was determined as follows:rapidly increasing in the initial period of 13.2-2.2 ka,reaching its maximum average value of 34.0 g·cm^(-2)·a^(-1)at 2.2-0.8 ka,then showing a decreasing trend with an average value of-77.5 g·cm^(-2)·a^(-1).Compared with regional climate change,Keshan black soil has developed under a colder and wetter climate during the Holocene.Predictably,ongoing global warming may lead to the degradation of black soils in the Songnen Plain,as well as in other regions.Our results will enrich geological knowledge of black soil formation and future evolutionary trends.展开更多
To determine the effects of preharvest arginine spraying on the nutritional level of broccoli and the mechanism of action of arginine in improving the storage quality of broccoli,arginine spraying(5 mmol/L)was conduct...To determine the effects of preharvest arginine spraying on the nutritional level of broccoli and the mechanism of action of arginine in improving the storage quality of broccoli,arginine spraying(5 mmol/L)was conducted at 0,1,3,and 5 days before harvest.The appearance,respiration rate,mass-loss rate,electrolyte leakage,glucosinolate,ascorbic acid,total phenol,total flavonoid,total sugar and sucrose contents,and sucrose phosphate synthase(SPS),invertase(INV),sucrose synthase synthesis(SSS)and cleavage(SSC)activities of broccoli samples were observed after 0,2,4,6,8,and 10 days of storage.The results showed that spraying arginine at 5 days preharvest(5-ARG)helped to inhibit broccoli respiration during storage,delay electrolyte leakage,and maintain broccoli color.Furthermore,during the growth stage,total sugar accumulation was higher in the 5-ARG group.In addition,during the storage period,sucrose synthesis was accelerated,while sucrose cleavage was inhibited,resulting in more sucrose retention in postharvest broccoli.In conclusion,5-ARG resulted in the accumulation of more nutrients during the growth process and effectively delayed the quality decline during storage,thereby prolonging the shelf life of broccoli.Therefore,this study provides a theoretical basis for improving postharvest storage characteristics of broccoli through preharvest treatments.展开更多
Coal measures are significant hydrocarbon source rocks and reservoirs in petroliferous basins.Many large gas fields and coalbed methane fields globally are originated from coal-measure source rocks or accumulated in c...Coal measures are significant hydrocarbon source rocks and reservoirs in petroliferous basins.Many large gas fields and coalbed methane fields globally are originated from coal-measure source rocks or accumulated in coal rocks.Inspired by the discovery of shale oil and gas,and guided by“the overall exploration concept of considering coal rock as reservoir”,breakthroughs in the exploration and development of coal-rock gas have been achieved in deep coal seams with favorable preservation conditions,thereby opening up a new development frontier for the unconventional gas in coal-rock reservoirs.Based on the data from exploration and development practices,a systematic study on the accumulation mechanism of coal-rock gas has been conducted.The mechanisms of“three fields”controlling coal-rock gas accumulation are revealed.It is confirmed that the coal-rock gas is different from CBM in accumulation process.The whole petroleum systems in the Carboniferous–Permian transitional facies coal measures of the eastern margin of the Ordos Basin and in the Jurassic continental facies coal measures of the Junggar Basin are characterized,and the key research directions for further developing the whole petroleum system theory of coal measures are proposed.Coal rocks,compared to shale,possess intense hydrocarbon generation potential,strong adsorption capacity,dual-medium reservoir properties,and partial or weak oil and gas self-sealing capacity.Additionally,unlike other unconventional gas such as shale gas and tight gas,coal-rock gas exhibits more complex accumulation characteristics,and its accumulation requires a certain coal-rock play form lithological and structural traps.Coal-rock gas also has the characteristics of conventional fractured gas reservoirs.Compared with the basic theory and model of the whole petroleum system established based on detrital rock formations,coal measures have distinct characteristics and differences in coal-rock reservoirs and source-reservoir coupling.The whole petroleum system of coal measures is composed of various types of coal-measure hydrocarbon plays with coal(and dark shale)in coal measures as source rock and reservoir,and with adjacent tight layers as reservoirs or cap or transport layers.Under the action of source-reservoir coupling,coal-rock gas is accumulated in coal-rock reservoirs with good preservation conditions,tight oil/gas is accumulated in tight layers,conventional oil/gas is accumulated in traps far away from sources,and coalbed methane is accumulated in coal-rock reservoirs damaged by later geological processes.The proposed whole petroleum system of coal measures represents a novel type of whole petroleum system.展开更多
Strip-till(ST),including straw mulching in the inter-row and localized fertilization in the intra-row,is a conservation tillage system for improving soil quality and crop growth.However,the yield advantage of maize un...Strip-till(ST),including straw mulching in the inter-row and localized fertilization in the intra-row,is a conservation tillage system for improving soil quality and crop growth.However,the yield advantage of maize under ST compared to conventional tillage(CT)remains unstable,and the strategies to increase maize yield under ST are unclear.This study aims to understand the physiological mechanism underlining maize yield formation under ST by comparing two maize cultivars,DKM753 and DK517,with contrasting yield performance in ST versus CT systems.Compared to CT,ST resulted in a 4.5%yield increase for DKM753 but a 5.6%decrease for DK517.These yield differences were primarily attributed to variations in grain number per ear(GN).During the rapid growth stage(V14-R3),i.e.,two weeks before and after silking,DKM753 showed a 6.7%increase in maximum growth rate(V_(max))and a 6.3%increase in average growth rate(V)under ST,whereas DK517 exhibited decline of 8.5%in V_(max) and 12.3%in V.Significant positive correlations are observed between V_(max) and V with GN under ST(R^(2)=0.79 and R^(2)=0.90,respectively).Enhanced dry matter accumulation in DKM753 under ST was attributed to increased leaf expansion rates,contributing to a larger photosynthate source.The straw mulching and localized nitrogen fertilization increased root-zone nitrogen availability at silking in ST compared to CT.DKM753 had a greater root system which made better use of the soil N and lead to an increased leaf nitrogen accumulation by 14.9%under ST.It is concluded that maize yield under the strip-till system is determined by grain number per ear,which can be increased by increasing nitrogen accumulation,plant growth,and ear development around silking stage.A sound root system can efficiently utilize soil nitrogen resources under the strip-till system,increasing plant nitrogen accumulation and thereby promoting plant growth.展开更多
Schwertmannite, a common iron-derived mineral, is known for its high efficiency in adsorbing As from water and reducing the mobility and availability of As in soils. However,few studies have examined the critical peri...Schwertmannite, a common iron-derived mineral, is known for its high efficiency in adsorbing As from water and reducing the mobility and availability of As in soils. However,few studies have examined the critical period for the effectiveness of schwertmannite in hindering As uptake by rice plants, particularly its impact on the uptake and transport of As across different growth stages of rice. In this study, hydroponic experiments were performed to explore the absorption and translocation of As(500 μg/L As(Ⅲ) or As(Ⅴ)), when combined with schwertmannite, in rice during all growth stages. The results showed that As concentration in roots, stems and leaves increased with rice growth, while the addition of schwertmannite reduced the As concentration in all parts of rice, compared to the control without schwertmannite. Besides, schwertmannite application mitigated the harmful impact of As on rice yield, and reduced As levels in grains by 66 %-90 % compared to treatments with only As(Ⅲ) or As(Ⅴ). The heading stage is identified as a critical period for applying schwertmannite to reduce As uptake in rice. Specifically, during the heading stages,the plants uptake 85 %-91 % of the As contents in the absence of schwertmannite. However,adding schwertmannite retained about 84 %-90 % of As content, significantly reducing its absorption by rice plants at this stage. Therefore, maintaining As adsorption by schwertmannite up to the heading stage is beneficial to effectively reduce As uptake in rice and lower As concentration in rice grains.展开更多
Research based on oil accumulation models is essential for exploring the hydrocarbon accumulation theory further.Studies on tight oil accumulation models focused on fan delta depositional systems,and in particular,sys...Research based on oil accumulation models is essential for exploring the hydrocarbon accumulation theory further.Studies on tight oil accumulation models focused on fan delta depositional systems,and in particular,systems involving source-reservoir separated type are scarce.To explore the accumulation model of tight oil in conglomerate,this study focused on the Permian-Triassic tight conglomerate oil in Mahu sag,Junggar Basin,using well drilling,well logging,seismic profiling,oil testing,and laboratory data,and analyzed the formation conditions,formation types,and distribution patterns of conglomerate reservoirs.The results show that,the conglomerate reservoirs are predominantly lithologic reservoirs and partly fault-lithologic reservoirs;there is no water evident at the edge or bottom around the reservoirs.The tight conglomerate layer in the delta plain subfacies of each fan exhibits high clay content and intense diagenesis,and the argillaceous rocks in the pro-fan delta subfacies and shallow lacustrine facies form the sealing and floor conditions.The sandy conglomerate of fan delta front subfacies is the main reservoir body.Additionally,strikeslip faulting in the Indosinian-Himalayan period formed an efficient faulting system for trans-stratal migration with Hercynian-Indosinian inverse faulting.Oil migration is driven by the overpressure caused by hydrocarbon generation from alkali lacustrine source rocks.The distribution of reservoirs is primarily controlled by the large fan bodies,namely the Zhongguai,Baijiantan,Karamay,Huangyangquan,Xiazijie,Xiayan,and Dabasong fans.Each fan body forms a group of reservoirs or oilfields,resulting in a widely distributed pattern,according to which reservoir and sealing constitute one whole body—i.e.,patterns of“one sand and one reservoir,one fan and one field.”This results in a quasi-continuous accumulation model,which includes strong oil charging,efficient faulting transportation,trans-stratal migration,and lithologic trapped accumulation.The proposed model is an important supplement to the existing model of quasi-continuous oil and gas accumulation.Overall,this study enriches unconventional oil and gas accumulation theories.展开更多
Obesity has brought great challenges to global human health,and how to effectively prevent and control the occurrence and development of obesity has become an urgent problem.The role and mechanism of 4-[(α-Lrhamnosyl...Obesity has brought great challenges to global human health,and how to effectively prevent and control the occurrence and development of obesity has become an urgent problem.The role and mechanism of 4-[(α-Lrhamnosyloxy)benzyl]isothiocyanate(MITC),an active ingredient of Moringa oleifera Lam.,in the regulation of lipid metabolism have not been comprehensively investigated.In the present study,we investigated the mechanism of MITC in inhibiting lipid accumulation in mice fed with a high-fat diet(HFD)in terms of both lipolysis and central appetite regulation mediated by the gut microbe-gut-brain axis.MITC enhanced the characteristic indices associated with HFD mice and also promoted adipocytolysis and brown fat thermogenesis.Moreover,MITC was observed to improve leptin resistance,modulate the composition of gut microbiota such as Ruminococcaceae,Parasutterella,and Acetatifactor,promote 5-hydroxytryptamine secretion,further enhance the secretion of glucagon-like peptide-1(GLP-1)and peptide tyrosine-tyrosine(PYY)to activate peroxisome proliferator-activated receptor(PPAR)signaling in the hypothalamus,and modulate feeding behavior to inhibit lipid accumulation in HFD mice.These data suggest that MITC supplementation can help to alleviate obesity or obesity-related diseases.展开更多
Light oil and gas reservoirs are abundant in the Ordovician marine carbonate reservoir in Shunbei Oilfield,Tarim Basin.This presents a compelling geological puzzle,as ultra-deep reservoirs undergo intense alteration a...Light oil and gas reservoirs are abundant in the Ordovician marine carbonate reservoir in Shunbei Oilfield,Tarim Basin.This presents a compelling geological puzzle,as ultra-deep reservoirs undergo intense alteration and complex petroleum accumulation processes.A comprehensive suite of geochemical analyses,including molecular components,carbon isotope composition,homogenization temperature of saline inclusions,and burial-thermal history of single wells,was conducted to elucidate the genesis of these ancient reservoirs.Three petroleum filling events have been identified in the study area:Late Caledonian,Hercynian-Indosinian,and Himalayan,through analysis of homogenization temperatures of brine inclusions and burial-thermal histories.Additionally,the oil in the study area has undergone significant alteration processes such as biodegradation,thermal alteration,mixing,evaporative fractionation,and gas invasion.This study particularly emphasizes the influential role of Himalayan gas filling-induced evaporation fractionation and gas invasion in shaping the present petroleum phase distribution.Furthermore,analysis of light hydrocarbon and diamondoid parameters indicates the oil within the study area is at a high maturity stage,with equivalent vitrinite reflectance values ranging from 1.48%to 1.99%.Additionally,the analysis of light hydrocarbons,aromatics,and thiadiamondoids indicates that TSR should occur in reservoirs near the gypsum-salt layers in the Cambrian.The existence of the Cambrian petroleum system in the study area is strongly confirmed when considering the analysis results of natural gas type(oil cracking gas),evaporative fractionation,and gas invasion.Permian local thermal anomalies notably emerge as a significant factor contributing to the destruction of biomarkers in oil.For oil not subject to transient,abnormal thermal events,biomarker reliability extends to at least 190℃.In conclusion,examining the special formation mechanisms and conditions of various secondary processes can offer valuable insights for reconstructing the history of petroleum accumulation in ultradeep reservoirs.This research provides a scientific foundation for advancing our knowledge of petroleum systems and underscores the importance of hydrocarbon geochemistry in unraveling ultra-deep,complex geological phenomena.展开更多
Carrots have an important role for a life of the men.Everybody can use carrots in the meals or the drinks,he uses carrots such as the medicaments to cure many diseases,too.Carrots are very necessary,we can tell the fo...Carrots have an important role for a life of the men.Everybody can use carrots in the meals or the drinks,he uses carrots such as the medicaments to cure many diseases,too.Carrots are very necessary,we can tell the following effects:carrots help improve eyesight,especially,carrots contain vitamin A,essential nutrients for health of the eyes.When our bodies have the vitamin A deficiency in the long time,visual cells in the eye retina can been hurt,make dry eyes,cause the visual disturbances and it is serious that everyone does not see.Carrots support to cure the diabetes;help strengthen the immunity;improve the health cardiovascular;help beautiful healthy skin;can reduce the risk of cancer.Besides,everyone drinks carrot juice to stimulate hair growth and stabilize blood pressure.Carrots contain a lot of beta carotene,fiber,vitamin K1,potassium as well as antioxidants and are grown popularly in all regions of Vietnam.The cultivating soil,irrigating water and carrot samples were collected in Loc Thanh village,Bao Lam district,Lam Dong province and some indicators were analyzed.The results showed that the soil sample was poor in nutrient by N,P,K indicators that were lower than the standards;but pH,Al3+and Fe3+were higher than the standards.The water sample did not contain the toxic heavy metals such as:As,Pb,Cd;but the indicators of Cu,Zn,Fe were higher than the standards.For the carrot sample,the indicators of As,Pb,Cu,Zn exceeded the allowable threshold;the contents of lipid and protein were lower than the standards but NO3-was within allowable standards.However,analysis of carrot samples grown by us using organic methods showed that some heavy metal indicators such as:As,Pb,Cu were lower than allowable standards.This showed that it is necessary to choose the type of soil,water and organic method for growing carrots in order to harvest good quality carrots and safety for users.We studied an environment of soil,water and analyzed the carrots to find a nutrition level,nutritional value and the metal accumulation in order to improve a life of men.展开更多
Deep neural networks remain susceptible to adversarial examples,where the goal of an adversarial attack is to introduce small perturbations to the original examples in order to confuse the model without being easily d...Deep neural networks remain susceptible to adversarial examples,where the goal of an adversarial attack is to introduce small perturbations to the original examples in order to confuse the model without being easily detected.Although many adversarial attack methods produce adversarial examples that have achieved great results in the whitebox setting,they exhibit low transferability in the black-box setting.In order to improve the transferability along the baseline of the gradient-based attack technique,we present a novel Stochastic Gradient Accumulation Momentum Iterative Attack(SAMI-FGSM)in this study.In particular,during each iteration,the gradient information is calculated using a normal sampling approach that randomly samples around the sample points,with the highest probability of capturing adversarial features.Meanwhile,the accumulated information of the sampled gradient from the previous iteration is further considered to modify the current updated gradient,and the original gradient attack direction is changed to ensure that the updated gradient direction is more stable.Comprehensive experiments conducted on the ImageNet dataset show that our method outperforms existing state-of-the-art gradient-based attack techniques,achieving an average improvement of 10.2%in transferability.展开更多
Cadmium(Cd)uptake by rice plants and its subsequent movement through food chains pose a notable risk to the health of both plants and humans.Therefore,understanding the fundamental mechanisms underlying the uptake and...Cadmium(Cd)uptake by rice plants and its subsequent movement through food chains pose a notable risk to the health of both plants and humans.Therefore,understanding the fundamental mechanisms underlying the uptake and movement process is essential.Through transcriptome analysis,we found that numerous abscisic acid(ABA)-related genes responded to Cd stress.Exogenous application of ABA significantly reduced Cd accumulation in the shoots and roots of rice plants.The increased ascorbate peroxidase(APX)enzyme activity,decreased H2O2 content,and elevated Cd tolerance index collectively suggest that ABA may mitigate the toxicity of Cd in rice plants.Further study revealed that exogenous ABA reduced Cd accumulation by regulating Cd transport and cell wall sequestration.Consistently,mutation of the ABA signaling factor OsABI5 resulted in a significant increase in Cd accumulation in shoots.Moreover,foliar spraying of ABA during the grain-filling stage significantly reduced Cd accumulation in rice grains,which was attributed mainly to decreased Cd uptake and the inhibition of Cd transportation from roots to shoots and from leaves to grains.These findings elucidate the underlying mechanisms of the ABA-mediated response to Cd stress in rice and provide a practical reference for coping with Cd pollution in farmlands.展开更多
Rapid industrial growth,urbanization,and agricultural activities have led to the discharge of large volumes of pollutants into coastal environments,raising levels of metals such as arsenic(As),cadmium(Cd),and mercury(...Rapid industrial growth,urbanization,and agricultural activities have led to the discharge of large volumes of pollutants into coastal environments,raising levels of metals such as arsenic(As),cadmium(Cd),and mercury(Hg)in water and sediments.Bivalve molluscs,such as Meretrix lyrata and Saccostrea glomerata can accumulate high amounts of toxic heavy metals in their tissues that pose potential risks to human health.They are frequently used as bioindicators due to their filter-feeding behavior and high accumulation potential.This study evaluates heavy metal accumulation in bivalve molluscs from Northeastern Vietnam,including Quang Ninh Province and Hai Phong City.In this study,a systematic literature review was conducted,combined with a bibliometric analysis,to synthesize and evaluate data on heavy metal accumulation in bivalve molluscs from Northeastern Vietnam.The analysis results showed bio-concentration factors exceeding 1,000 for As,Cd,and Hg in certain species,particularly in samples from Quang Ninh Province.Meanwhile,sediment accumulation factors(BSAF)were lower,suggesting that waterborne pathways predominantly contribute to heavy metal uptake.These findings highlight significant food safety risks due to toxic metal accumulation in seafood resources,emphasizing the urgent need for continuous monitoring and the establishment of local safety standards.The study provides important scientific evidence to support marine environmental management and public health protection.展开更多
Siraitia grosvenorii(SG),a traditional edible medicine in China,has shown potential application in health foods due to multiple bioactivities.However,few comparative studies have investigated the effect of daily intak...Siraitia grosvenorii(SG),a traditional edible medicine in China,has shown potential application in health foods due to multiple bioactivities.However,few comparative studies have investigated the effect of daily intake of SG products by traditional drinking way on alleviating metabolic disorders caused by long-term high fat and high sugar diet(HF-HSD).This study investigated the effects of 2 commercial SG products(SG juice containing comprehensive compositions and mogrosides extract containing high content of mogroside V)supplement on fat content,lipid accumulation,colon barrier and gut microbiota in a 38-week HF-HSD mice trial.Results showed that the SG intervention could decrease the weight gain and body fat content,alleviated lipid accumulation,low-grade inflammation and colon barrier injury.SG juice intake was found to increase the antioxidant enzyme activities of serum glutathione peroxidase and liver superoxide dismutase.16S r RNA analysis found that SG could restore the gut microbiota with downregulation of harmful bacteria increased by HF-HSD and enhancement of the abundances of beneficial genus.In particular,SG juice significantly enriched taxonomic family Prevotellaceae and genus Alloprevotella.These results indicated that SG might be a functional additive to prevent disease risk caused by excess fat and sugar diet,and active ingredients resulting to the discrepancy of performance especially on gut microbiota are worthy of in-depth investigation.展开更多
Brassica napus,one of the most important oil crops cultivated globally,is severely impacted by prolonged soil contamination with cadmium(Cd),resulting in decreased yields and poor seed quality.This crop exhibits a hig...Brassica napus,one of the most important oil crops cultivated globally,is severely impacted by prolonged soil contamination with cadmium(Cd),resulting in decreased yields and poor seed quality.This crop exhibits a high adsorption capacity for Cd,making creating seed resources with low Cd accumulation an essential strategy to alleviate this challenge.To address this issue,we genetically edited BnaNRAMP1 in B.napus by targeting three different exon regions,resulting in new germplasm resources with significant differences in Cd accumulation capacity and unaffected yield.Among these,the mutant K140-22,specifically targeting the 7th exon,is distinguished by its substantially reduced Cd accumulation.Further,enzyme assays of the antioxidant defense system in both roots and shoots of K140-22 revealed its enhanced antioxidant activity,which contributes to elucidating the molecular mechanisms of plant tolerance to heavy metal stress.Remarkably,this mutant also maintained equivalent agronomic traits and seed quality,which highlights its potential as a germplasm resource for rapeseed breeding for low Cd accumulation and elevating rapeseed economic value in Cd-contaminated soil.展开更多
There are abundant hydrothermal events within the Dengying Formation dolomite of the Precambrian system in southwest China.Methods including petrography identification,fluid-inclusion observation,in-situ U-Pb dating,a...There are abundant hydrothermal events within the Dengying Formation dolomite of the Precambrian system in southwest China.Methods including petrography identification,fluid-inclusion observation,in-situ U-Pb dating,and in-situ measurement of rare earth element(REE),etc.are integrated to characterize hydrothermal activity process within the Dengying Formation dolomite.The hydrothermal activity therein can be divided into four stages on the basis of in-situ U-Pb dating results of saddle dolomite cements.The 1st-stage(415.0-400.0 Ma)and 2nd-stage(259.4-248.0 Ma)hydrothermal events are characterized by saddle dolomite filling along the margin of fractures,or filling within dilational breccia and zebra textures.Compared with matrix dolomite and seawater-derived fibrous dolomite,saddle dolomite exhibits obvious negative anomalies of Ce elements.The 3rd-stage(225.6-199.0 Ma)hydrothermal event is represented by galena,sphalerite and other Mississipppi Valley-type(MVT)mineral cements in residual space.The formation of lead-zinc ore is due to the precipitation of metal sulfide caused by the thermo-chemical sulfate reduction(TSR)reaction between hydrothermal fluids and hydrocarbons during the large-scale hydrocarbon charging period.The 4th-stage(130.0-41.0 Ma)hydrothermal event is characterized by quartz and a small amount of fluorite filling the residual pores with dolomites.Quartz and fluorite record the migration of deep high-temperature hydrothermal fluid along early fractures and residual pores.During this period,the hydrothermal fluids result in the heterogeneous structure of bitumen,which is a clear response to high-temperature hydrothermal activity.展开更多
With the development of unconventional hydrocarbon, how to improve the shale oil and gas recovery become urgent. Therefore hydraulic fracturing becomes the key due to the complicated properties of the reservoirs. The ...With the development of unconventional hydrocarbon, how to improve the shale oil and gas recovery become urgent. Therefore hydraulic fracturing becomes the key due to the complicated properties of the reservoirs. The pore structure not only plays an essential role in the formation of complex fracture networks after fracturing but also in resource accumulation mechanism analyses. The lacustrine organicrich shale samples were selected to carry out petrophysical experiments. Scanning Electron Microscopy(SEM) and X-ray Diffraction were performed to elucidate the geology characteristics. MICP, 2D NMR, CT,and N2adsorption were conducted to classify the pore structure types. The contribution of pore structure to oil accumulation and hydrocarbon enrichment was explained through the N2adsorption test on the original and extracted state and 2D NMR. The results show that micropores with diameter less than20 nm are well-developed. The pore structure was divided into three types. Type Ⅰ is characterized by high porosity, lower surface area, and good pore throat connectivity, with free oil existing in large pores,especially lamellation fractures. The dominant nano-pores are spongy organic pores and resources hosted in large pores have been expelled during high thermal evolution. The content of nano-pores(micropores) increases and the pore volume decreases in Type Ⅱ pore structure. In addition, more absorbed oil was enriched. The pore size distribution of type Ⅱ is similar to that of type Ⅰ. However, the maturity and hydrocarbon accumulation is quite different. The oil reserved in large pores was not expelled attributed to the relatively low thermal evolution compared with type Ⅰ. Structural vitrinite was observed through SEM indicating kerogen of type Ⅲ developed in this kind of reservoir while the type of kerogen in pore structure Ⅰ is type Ⅱ. Type Ⅲ pore structure is characterized by the largest surface area,lowest porosity, and almost isolated pores with rarely free oil. Type Ⅰ makes the most contribution to hydrocarbon accumulation and immigration, which shows the best prospect. Of all of these experiments,N2adsorption exhibits the best in characterizing pores in shales due to its high resolution for the assessment of nano-scale pores. MICP and NMR have a better advantage in characterizing pore space of sandstone reservoirs, even tight sandstone reservoirs. 2D NMR plays an essential role in fluid recognition and saturation calculation. CT scanning provides a 3D visualization of reservoir space and directly shows the relationship between pores and throats and the characteristics of fractures. This study hopes to guide experiment selection in pore structure characterization in different reservoirs. This research provides insight into hydrocarbon accumulation of shales and guidance in the exploration and development of unconventional resources, for example for geothermal and CCUS reservoirs.展开更多
The Shenhu Area in the South China Sea is rich in oil and gas resources and has many vertical gas chimneys,making it an excellent geological environment for hydrate accumulation.This paper examines the geological cond...The Shenhu Area in the South China Sea is rich in oil and gas resources and has many vertical gas chimneys,making it an excellent geological environment for hydrate accumulation.This paper examines the geological conditions governing these gas-chimneys.A numerical simulation method based on the partial-equilibrium reaction model of hydrate was applied to simulate the migration of methane gas and the resultant hydrate formation when the gas enters the hydrate stability zone under the seabed through gas-chimneys.The dynamics of this gaschimney hydrate accumulation were analyzed,and the influences of different factors―namely,the fluid supply time,rate,and temperature―on the formation temperature and ultimate distribution of the hydrate reservoir were evaluated.The simulation results indicate that the accumulation of hydrate via gas-chimneys is significantly affected by the temperature of the gas source,the transfer state of the methane gas,and the number of cycles of alternating gas-water invasion.Hydrate accumulation takes shape in an annular or semi-annular distribution pattern divided by fluid state as follows:a two-phase gas-water zone,a three-phase gas-water-hydrate zone,a two-phase water-hydrate zone,and a phase of water passing from the inside to the outside.Formation inclination and reservoir heterogeneity can greatly affect the distribution shape and abundance of the hydrate.A high fluid supply temperature,frequent alternating invasions of gas and water,and long-term pore-water invasion at a high rate can jointly cause a large central hydrate-free zone.In contrast,a long-term supply shutdown during the alternating gas-water invasion process,and a high gas rate with a low water rate in the gas-dominant invasion stage,foster the accumulation of hydrate in great abundance and with considerable thickness.The results of this study can help us understand the accumulation of hydrate through gas chimneys in the Shenhu Area.展开更多
Bauxite mining will bring huge economic benefit,but it also faces the risk of environmental pollution.Metal pollution problem has been widely concerned in bauxite tailing areas.Biodiversity indices,metal concentration...Bauxite mining will bring huge economic benefit,but it also faces the risk of environmental pollution.Metal pollution problem has been widely concerned in bauxite tailing areas.Biodiversity indices,metal concentrations of moss crusts,and soil contamination indices in Wachangping bauxite tailing areas in Guizhou Province,China were measured and analyzed.In a total of 40 species belonging to 19 genera and 12 families of moss in the study areas,Ditrichum flexicaule(Schwaegr.)Hamp.(DF),Oxystegus cylindricus(Brid.)Hilp.(OC),and Ditrichum brevidens Nog.(DB)are the dominant moss crusts.Moss species diversity in different habitats has a certain regularity:waste residues area<waste rocks area<ore stockpile area<slope shrub area<shrub area by gutter<slope shrub herbaceous area.Sorenson diversity index(β)of moss species is influenced by microenvironment and substrate.Concentrations of Al,Mg,Ca,Fe,K,and Ti are the largest in DB(2,990 to 73,210 mg kg^(-1)),followed by those in DF(2,900 to 61,890 mg kg^(-1)),and are the smallest in OC(690 to 32,240 mg kg^(-1)),which show that the three moss crusts have different bioaccumulation capacities.Metal contents in underlying soils of moss crusts are higher than the background levels.Bioaccumulation factor(BAF)of Al,Mg,Ca,Fe,and K in three moss crusts are decreased in the following order:DB>DF>OC.Single factor pollution index(Ps)and Nemero comprehensive pollution index(Pc)of six metal are much greater than 3,and the index of geoaccumulation(Igeo)(1geo<5)reveals that the soil environment is at moderately to seriously contaminated levels.Principal components analysis(PCA)shows that there is no significant correlation between p H value,and metal contents(Al,Mg,Fe,K and Ti),soil temperature(ST)and metal contents(Al,Mg,Fe,K and Ti).Soil humidity(SH)is negatively correlated with metal contents(Al,Mg,Fe,K and Ti).These three environmental factors have little effect on the distribution of metal.Result also reflects that DB moss is readily able to both tolerate and accumulate metal,which makes it a suitable bioindicator of multiple metal contamination in Wachangping bauxite tailing areas.展开更多
Aluminium(Al)toxicity is one of the key factors limiting crop output in acidic soils,but until now little has been known about how Al is regulated transcriptionally in plants.This study identified Arabidopsis NAC tran...Aluminium(Al)toxicity is one of the key factors limiting crop output in acidic soils,but until now little has been known about how Al is regulated transcriptionally in plants.This study identified Arabidopsis NAC transcription factor ANAC050 in the regulation of Al tolerance.ANAC050 was located in the nucleus and displayed constitutive expression in the silique,flower,leaf,stem,and root,despite the fact that Al stress decreased its expression and protein accumulation.When compared with the Columbia ecotype wild-type,anac050 mutants that lacked function of ANAC050 exhibited Al sensitivity phenotype,while transgenic lines that overexpressed ANAC050 showed an Al-resistant phenotype,indicating the favorable influence of ANAC050 on preserving Al tolerance in plants.Further analysis indicated that anac050 mutants accumulated more Al in roots,implying that ANAC050 may confer a potential operation of an Al exclusion mechanism.Interestingly,anac050 mutants had down-regulated the expression of the genes encoding MULTIDRUG AND TOXIC COMPOUND EXTRUSION(MATE)and AL-ACTIVATED MALATE TRANSPORTER(ALMT1),which were involved in the secretion of citrate and malate,even though there was no evidence of a direct interaction between them,suggesting ANAC050 may mediate the secretion of citrate and malate indirectly.Together with the decreased hemicellulose content,lower Al content was also discovered in root cell walls and hemicelluloses of anac050 mutants,pointing to a potential interaction between ANAC017 and XYLOGLUCAN ENDOTRANSGLUCOSYLASE/HYDROLASE(XTH).Although there was no evidence of a direct interaction between ANAC050 and XTH31,it is worth mentioning that the expression of XTH31,which is essential for xyloglucan modification,was down-regulated in anac050 mutants irrespective of the amount of Al given.In conclusion,our findings showed that ANAC050 contributed to Al resistance by indirect control of the release of organic acids and the accumulation of cell wall hemicelluloses.展开更多
基金supported by the National Natural Science Foundation of China(Nos.32171623 and 31770548)the National Key Research and Development Program of China(Nos.2016YFD0800306 and 2017YFD0800305).
文摘Arsenic(As)pollution seriously threatens human and ecological health.Microalgal cell wall and extracellular polymeric substances(EPS)are known to interactwith As,but their roles in the As resistance,accumulation and speciation inmicroalgae remain unclear.Here,we used two strains of Chlamydomonas reinhardtii,namely CC-125(wild type)and CC-503(cell walldeficientmutant),to examine the algal growth,EPS synthesis,As adsorption,absorption and transformation under 10–1000μg/L As(III)and As(V)treatments for 96 h.In both strains,the As absorption increased after the EPS removal,but the growth,As adsorption,and transformation of C.reinhardtii declined.The CC-125 strain was more tolerant to As stress and more efficient in EPS production,As accumulation,and redox transformation than CC-503,irrespective of EPS presence or absence.Three-dimension excitation-emission matrix(3DEEM)and attenuated total reflectance infrared spectroscopy(ATR-IR)analyses showed that As was bound with functional groups in the EPS and cell wall,such as-COOH,NH and-OH in proteins,polysaccharides and amino acids.Together,this study demonstrated that EPS and cell wall acted as barriers to lower the As uptake by C.reinhardtii.However,the cell wall mutant strain wasmore susceptible to As toxicity due to lower EPS induction and higher As absorption.
基金financially supported by the Science and Technology Innovation Foundation of the Command Center of Integrated Natural Resources Survey Center(KC20230002)the China Geological Survey Project(DD20230471,DD20220855 and DD20243282)+1 种基金the National Natural Science Foundation of China(41872100)the National Key R&D Plan(2022YFC2903402)。
文摘Black soil is essential for maintaining regional food security and promoting global agricultural production.Understanding the weathering process of parent material and the accumulation of organic carbon is crucial to comprehending the developmental history and future trends of black soil,especially against the background of large-scale global cultivation and climate change.Although the importance of black soil formation and evolution cannot be ignored,the relevant research is still very scarce.In this study,a typical eight-meter-deep soil core was collected from the Keshan area of the Songnen Plain,Northeast China,where surface black soil developed on paleo-sediments.Using^(14)C dating,the formation age of the black soil was determined.Based on the characteristics of the geochemical composition,grain size and the magnetic susceptibility of the sediments,it was demonstrated that the black soil and its parent material originated from reworked loess.Furthermore,the mass transfer coefficient(τ)of some elements was determined,in order to explore the soil weathering process.By calculating the transported amount of alkaline and alkaline-earth elements,the weathering rate of parent material to black soil was found to be weak,at 0.16 kEq·ha^(-1)·year^(-1).Combining the results of dating and carbon density in the different layers of black soil,the accumulation rate of organic carbon was determined as follows:rapidly increasing in the initial period of 13.2-2.2 ka,reaching its maximum average value of 34.0 g·cm^(-2)·a^(-1)at 2.2-0.8 ka,then showing a decreasing trend with an average value of-77.5 g·cm^(-2)·a^(-1).Compared with regional climate change,Keshan black soil has developed under a colder and wetter climate during the Holocene.Predictably,ongoing global warming may lead to the degradation of black soils in the Songnen Plain,as well as in other regions.Our results will enrich geological knowledge of black soil formation and future evolutionary trends.
文摘To determine the effects of preharvest arginine spraying on the nutritional level of broccoli and the mechanism of action of arginine in improving the storage quality of broccoli,arginine spraying(5 mmol/L)was conducted at 0,1,3,and 5 days before harvest.The appearance,respiration rate,mass-loss rate,electrolyte leakage,glucosinolate,ascorbic acid,total phenol,total flavonoid,total sugar and sucrose contents,and sucrose phosphate synthase(SPS),invertase(INV),sucrose synthase synthesis(SSS)and cleavage(SSC)activities of broccoli samples were observed after 0,2,4,6,8,and 10 days of storage.The results showed that spraying arginine at 5 days preharvest(5-ARG)helped to inhibit broccoli respiration during storage,delay electrolyte leakage,and maintain broccoli color.Furthermore,during the growth stage,total sugar accumulation was higher in the 5-ARG group.In addition,during the storage period,sucrose synthesis was accelerated,while sucrose cleavage was inhibited,resulting in more sucrose retention in postharvest broccoli.In conclusion,5-ARG resulted in the accumulation of more nutrients during the growth process and effectively delayed the quality decline during storage,thereby prolonging the shelf life of broccoli.Therefore,this study provides a theoretical basis for improving postharvest storage characteristics of broccoli through preharvest treatments.
基金Supported by the PetroChina Basic Project(2024DJ23)CNPC Science Research and Technology Development Project(2021DJ0101)。
文摘Coal measures are significant hydrocarbon source rocks and reservoirs in petroliferous basins.Many large gas fields and coalbed methane fields globally are originated from coal-measure source rocks or accumulated in coal rocks.Inspired by the discovery of shale oil and gas,and guided by“the overall exploration concept of considering coal rock as reservoir”,breakthroughs in the exploration and development of coal-rock gas have been achieved in deep coal seams with favorable preservation conditions,thereby opening up a new development frontier for the unconventional gas in coal-rock reservoirs.Based on the data from exploration and development practices,a systematic study on the accumulation mechanism of coal-rock gas has been conducted.The mechanisms of“three fields”controlling coal-rock gas accumulation are revealed.It is confirmed that the coal-rock gas is different from CBM in accumulation process.The whole petroleum systems in the Carboniferous–Permian transitional facies coal measures of the eastern margin of the Ordos Basin and in the Jurassic continental facies coal measures of the Junggar Basin are characterized,and the key research directions for further developing the whole petroleum system theory of coal measures are proposed.Coal rocks,compared to shale,possess intense hydrocarbon generation potential,strong adsorption capacity,dual-medium reservoir properties,and partial or weak oil and gas self-sealing capacity.Additionally,unlike other unconventional gas such as shale gas and tight gas,coal-rock gas exhibits more complex accumulation characteristics,and its accumulation requires a certain coal-rock play form lithological and structural traps.Coal-rock gas also has the characteristics of conventional fractured gas reservoirs.Compared with the basic theory and model of the whole petroleum system established based on detrital rock formations,coal measures have distinct characteristics and differences in coal-rock reservoirs and source-reservoir coupling.The whole petroleum system of coal measures is composed of various types of coal-measure hydrocarbon plays with coal(and dark shale)in coal measures as source rock and reservoir,and with adjacent tight layers as reservoirs or cap or transport layers.Under the action of source-reservoir coupling,coal-rock gas is accumulated in coal-rock reservoirs with good preservation conditions,tight oil/gas is accumulated in tight layers,conventional oil/gas is accumulated in traps far away from sources,and coalbed methane is accumulated in coal-rock reservoirs damaged by later geological processes.The proposed whole petroleum system of coal measures represents a novel type of whole petroleum system.
基金the National Key Research and Development Program of China(2022YFD1500705)National Natural Science Foundation of China(U19A2035)for financial support。
文摘Strip-till(ST),including straw mulching in the inter-row and localized fertilization in the intra-row,is a conservation tillage system for improving soil quality and crop growth.However,the yield advantage of maize under ST compared to conventional tillage(CT)remains unstable,and the strategies to increase maize yield under ST are unclear.This study aims to understand the physiological mechanism underlining maize yield formation under ST by comparing two maize cultivars,DKM753 and DK517,with contrasting yield performance in ST versus CT systems.Compared to CT,ST resulted in a 4.5%yield increase for DKM753 but a 5.6%decrease for DK517.These yield differences were primarily attributed to variations in grain number per ear(GN).During the rapid growth stage(V14-R3),i.e.,two weeks before and after silking,DKM753 showed a 6.7%increase in maximum growth rate(V_(max))and a 6.3%increase in average growth rate(V)under ST,whereas DK517 exhibited decline of 8.5%in V_(max) and 12.3%in V.Significant positive correlations are observed between V_(max) and V with GN under ST(R^(2)=0.79 and R^(2)=0.90,respectively).Enhanced dry matter accumulation in DKM753 under ST was attributed to increased leaf expansion rates,contributing to a larger photosynthate source.The straw mulching and localized nitrogen fertilization increased root-zone nitrogen availability at silking in ST compared to CT.DKM753 had a greater root system which made better use of the soil N and lead to an increased leaf nitrogen accumulation by 14.9%under ST.It is concluded that maize yield under the strip-till system is determined by grain number per ear,which can be increased by increasing nitrogen accumulation,plant growth,and ear development around silking stage.A sound root system can efficiently utilize soil nitrogen resources under the strip-till system,increasing plant nitrogen accumulation and thereby promoting plant growth.
基金supported by the National Natural Science Foundation of China(Nos.22336003 and 42177222)the National Key Research and Development Program of China(No.2023YFC3707600).
文摘Schwertmannite, a common iron-derived mineral, is known for its high efficiency in adsorbing As from water and reducing the mobility and availability of As in soils. However,few studies have examined the critical period for the effectiveness of schwertmannite in hindering As uptake by rice plants, particularly its impact on the uptake and transport of As across different growth stages of rice. In this study, hydroponic experiments were performed to explore the absorption and translocation of As(500 μg/L As(Ⅲ) or As(Ⅴ)), when combined with schwertmannite, in rice during all growth stages. The results showed that As concentration in roots, stems and leaves increased with rice growth, while the addition of schwertmannite reduced the As concentration in all parts of rice, compared to the control without schwertmannite. Besides, schwertmannite application mitigated the harmful impact of As on rice yield, and reduced As levels in grains by 66 %-90 % compared to treatments with only As(Ⅲ) or As(Ⅴ). The heading stage is identified as a critical period for applying schwertmannite to reduce As uptake in rice. Specifically, during the heading stages,the plants uptake 85 %-91 % of the As contents in the absence of schwertmannite. However,adding schwertmannite retained about 84 %-90 % of As content, significantly reducing its absorption by rice plants at this stage. Therefore, maintaining As adsorption by schwertmannite up to the heading stage is beneficial to effectively reduce As uptake in rice and lower As concentration in rice grains.
基金the National Science and Technology Major Project of China for their support。
文摘Research based on oil accumulation models is essential for exploring the hydrocarbon accumulation theory further.Studies on tight oil accumulation models focused on fan delta depositional systems,and in particular,systems involving source-reservoir separated type are scarce.To explore the accumulation model of tight oil in conglomerate,this study focused on the Permian-Triassic tight conglomerate oil in Mahu sag,Junggar Basin,using well drilling,well logging,seismic profiling,oil testing,and laboratory data,and analyzed the formation conditions,formation types,and distribution patterns of conglomerate reservoirs.The results show that,the conglomerate reservoirs are predominantly lithologic reservoirs and partly fault-lithologic reservoirs;there is no water evident at the edge or bottom around the reservoirs.The tight conglomerate layer in the delta plain subfacies of each fan exhibits high clay content and intense diagenesis,and the argillaceous rocks in the pro-fan delta subfacies and shallow lacustrine facies form the sealing and floor conditions.The sandy conglomerate of fan delta front subfacies is the main reservoir body.Additionally,strikeslip faulting in the Indosinian-Himalayan period formed an efficient faulting system for trans-stratal migration with Hercynian-Indosinian inverse faulting.Oil migration is driven by the overpressure caused by hydrocarbon generation from alkali lacustrine source rocks.The distribution of reservoirs is primarily controlled by the large fan bodies,namely the Zhongguai,Baijiantan,Karamay,Huangyangquan,Xiazijie,Xiayan,and Dabasong fans.Each fan body forms a group of reservoirs or oilfields,resulting in a widely distributed pattern,according to which reservoir and sealing constitute one whole body—i.e.,patterns of“one sand and one reservoir,one fan and one field.”This results in a quasi-continuous accumulation model,which includes strong oil charging,efficient faulting transportation,trans-stratal migration,and lithologic trapped accumulation.The proposed model is an important supplement to the existing model of quasi-continuous oil and gas accumulation.Overall,this study enriches unconventional oil and gas accumulation theories.
基金supported by the Basic Research Project of Yunnan Provincial Science and Technology Department(202201AT070262)the Project of Yunnan Province Food and Drug Homologous Resources Functional Food Innovation Team(A3032023057)+1 种基金the Yunnan Province Ten Thousand Plan Industrial Technology Talents Project(YNWR-CYJS-2020-010)the Yunnan Province-City Integration Project(202302 AN360002).
文摘Obesity has brought great challenges to global human health,and how to effectively prevent and control the occurrence and development of obesity has become an urgent problem.The role and mechanism of 4-[(α-Lrhamnosyloxy)benzyl]isothiocyanate(MITC),an active ingredient of Moringa oleifera Lam.,in the regulation of lipid metabolism have not been comprehensively investigated.In the present study,we investigated the mechanism of MITC in inhibiting lipid accumulation in mice fed with a high-fat diet(HFD)in terms of both lipolysis and central appetite regulation mediated by the gut microbe-gut-brain axis.MITC enhanced the characteristic indices associated with HFD mice and also promoted adipocytolysis and brown fat thermogenesis.Moreover,MITC was observed to improve leptin resistance,modulate the composition of gut microbiota such as Ruminococcaceae,Parasutterella,and Acetatifactor,promote 5-hydroxytryptamine secretion,further enhance the secretion of glucagon-like peptide-1(GLP-1)and peptide tyrosine-tyrosine(PYY)to activate peroxisome proliferator-activated receptor(PPAR)signaling in the hypothalamus,and modulate feeding behavior to inhibit lipid accumulation in HFD mice.These data suggest that MITC supplementation can help to alleviate obesity or obesity-related diseases.
基金funded by the National Natural Science Foundations of China(Grant No.42173054)。
文摘Light oil and gas reservoirs are abundant in the Ordovician marine carbonate reservoir in Shunbei Oilfield,Tarim Basin.This presents a compelling geological puzzle,as ultra-deep reservoirs undergo intense alteration and complex petroleum accumulation processes.A comprehensive suite of geochemical analyses,including molecular components,carbon isotope composition,homogenization temperature of saline inclusions,and burial-thermal history of single wells,was conducted to elucidate the genesis of these ancient reservoirs.Three petroleum filling events have been identified in the study area:Late Caledonian,Hercynian-Indosinian,and Himalayan,through analysis of homogenization temperatures of brine inclusions and burial-thermal histories.Additionally,the oil in the study area has undergone significant alteration processes such as biodegradation,thermal alteration,mixing,evaporative fractionation,and gas invasion.This study particularly emphasizes the influential role of Himalayan gas filling-induced evaporation fractionation and gas invasion in shaping the present petroleum phase distribution.Furthermore,analysis of light hydrocarbon and diamondoid parameters indicates the oil within the study area is at a high maturity stage,with equivalent vitrinite reflectance values ranging from 1.48%to 1.99%.Additionally,the analysis of light hydrocarbons,aromatics,and thiadiamondoids indicates that TSR should occur in reservoirs near the gypsum-salt layers in the Cambrian.The existence of the Cambrian petroleum system in the study area is strongly confirmed when considering the analysis results of natural gas type(oil cracking gas),evaporative fractionation,and gas invasion.Permian local thermal anomalies notably emerge as a significant factor contributing to the destruction of biomarkers in oil.For oil not subject to transient,abnormal thermal events,biomarker reliability extends to at least 190℃.In conclusion,examining the special formation mechanisms and conditions of various secondary processes can offer valuable insights for reconstructing the history of petroleum accumulation in ultradeep reservoirs.This research provides a scientific foundation for advancing our knowledge of petroleum systems and underscores the importance of hydrocarbon geochemistry in unraveling ultra-deep,complex geological phenomena.
文摘Carrots have an important role for a life of the men.Everybody can use carrots in the meals or the drinks,he uses carrots such as the medicaments to cure many diseases,too.Carrots are very necessary,we can tell the following effects:carrots help improve eyesight,especially,carrots contain vitamin A,essential nutrients for health of the eyes.When our bodies have the vitamin A deficiency in the long time,visual cells in the eye retina can been hurt,make dry eyes,cause the visual disturbances and it is serious that everyone does not see.Carrots support to cure the diabetes;help strengthen the immunity;improve the health cardiovascular;help beautiful healthy skin;can reduce the risk of cancer.Besides,everyone drinks carrot juice to stimulate hair growth and stabilize blood pressure.Carrots contain a lot of beta carotene,fiber,vitamin K1,potassium as well as antioxidants and are grown popularly in all regions of Vietnam.The cultivating soil,irrigating water and carrot samples were collected in Loc Thanh village,Bao Lam district,Lam Dong province and some indicators were analyzed.The results showed that the soil sample was poor in nutrient by N,P,K indicators that were lower than the standards;but pH,Al3+and Fe3+were higher than the standards.The water sample did not contain the toxic heavy metals such as:As,Pb,Cd;but the indicators of Cu,Zn,Fe were higher than the standards.For the carrot sample,the indicators of As,Pb,Cu,Zn exceeded the allowable threshold;the contents of lipid and protein were lower than the standards but NO3-was within allowable standards.However,analysis of carrot samples grown by us using organic methods showed that some heavy metal indicators such as:As,Pb,Cu were lower than allowable standards.This showed that it is necessary to choose the type of soil,water and organic method for growing carrots in order to harvest good quality carrots and safety for users.We studied an environment of soil,water and analyzed the carrots to find a nutrition level,nutritional value and the metal accumulation in order to improve a life of men.
基金supported in part by the National Natural Science Foundation(62202118,U24A20241)in part by Major Scientific and Technological Special Project of Guizhou Province([2024]014,[2024]003)+1 种基金in part by Scientific and Technological Research Projects from Guizhou Education Department(Qian jiao ji[2023]003)in part by Guizhou Science and Technology Department Hundred Level Innovative Talents Project(GCC[2023]018).
文摘Deep neural networks remain susceptible to adversarial examples,where the goal of an adversarial attack is to introduce small perturbations to the original examples in order to confuse the model without being easily detected.Although many adversarial attack methods produce adversarial examples that have achieved great results in the whitebox setting,they exhibit low transferability in the black-box setting.In order to improve the transferability along the baseline of the gradient-based attack technique,we present a novel Stochastic Gradient Accumulation Momentum Iterative Attack(SAMI-FGSM)in this study.In particular,during each iteration,the gradient information is calculated using a normal sampling approach that randomly samples around the sample points,with the highest probability of capturing adversarial features.Meanwhile,the accumulated information of the sampled gradient from the previous iteration is further considered to modify the current updated gradient,and the original gradient attack direction is changed to ensure that the updated gradient direction is more stable.Comprehensive experiments conducted on the ImageNet dataset show that our method outperforms existing state-of-the-art gradient-based attack techniques,achieving an average improvement of 10.2%in transferability.
基金support from the National Natural Science Foundation of China(U20A2024)the National Key Research and Development Program of China(2023YFD2301300).
文摘Cadmium(Cd)uptake by rice plants and its subsequent movement through food chains pose a notable risk to the health of both plants and humans.Therefore,understanding the fundamental mechanisms underlying the uptake and movement process is essential.Through transcriptome analysis,we found that numerous abscisic acid(ABA)-related genes responded to Cd stress.Exogenous application of ABA significantly reduced Cd accumulation in the shoots and roots of rice plants.The increased ascorbate peroxidase(APX)enzyme activity,decreased H2O2 content,and elevated Cd tolerance index collectively suggest that ABA may mitigate the toxicity of Cd in rice plants.Further study revealed that exogenous ABA reduced Cd accumulation by regulating Cd transport and cell wall sequestration.Consistently,mutation of the ABA signaling factor OsABI5 resulted in a significant increase in Cd accumulation in shoots.Moreover,foliar spraying of ABA during the grain-filling stage significantly reduced Cd accumulation in rice grains,which was attributed mainly to decreased Cd uptake and the inhibition of Cd transportation from roots to shoots and from leaves to grains.These findings elucidate the underlying mechanisms of the ABA-mediated response to Cd stress in rice and provide a practical reference for coping with Cd pollution in farmlands.
文摘Rapid industrial growth,urbanization,and agricultural activities have led to the discharge of large volumes of pollutants into coastal environments,raising levels of metals such as arsenic(As),cadmium(Cd),and mercury(Hg)in water and sediments.Bivalve molluscs,such as Meretrix lyrata and Saccostrea glomerata can accumulate high amounts of toxic heavy metals in their tissues that pose potential risks to human health.They are frequently used as bioindicators due to their filter-feeding behavior and high accumulation potential.This study evaluates heavy metal accumulation in bivalve molluscs from Northeastern Vietnam,including Quang Ninh Province and Hai Phong City.In this study,a systematic literature review was conducted,combined with a bibliometric analysis,to synthesize and evaluate data on heavy metal accumulation in bivalve molluscs from Northeastern Vietnam.The analysis results showed bio-concentration factors exceeding 1,000 for As,Cd,and Hg in certain species,particularly in samples from Quang Ninh Province.Meanwhile,sediment accumulation factors(BSAF)were lower,suggesting that waterborne pathways predominantly contribute to heavy metal uptake.These findings highlight significant food safety risks due to toxic metal accumulation in seafood resources,emphasizing the urgent need for continuous monitoring and the establishment of local safety standards.The study provides important scientific evidence to support marine environmental management and public health protection.
基金funded by Guangxi Science and Technology Major Project(Guike AA23023035,Guike AA22096020)the Joint Funds of the National Natural Science Foundation of China(U20A2004)+1 种基金Guilin Innovation Platform and Talent Plan(20210102-3)Guangxi Science and Technology Base and Talent Project(Guike AA21196009)。
文摘Siraitia grosvenorii(SG),a traditional edible medicine in China,has shown potential application in health foods due to multiple bioactivities.However,few comparative studies have investigated the effect of daily intake of SG products by traditional drinking way on alleviating metabolic disorders caused by long-term high fat and high sugar diet(HF-HSD).This study investigated the effects of 2 commercial SG products(SG juice containing comprehensive compositions and mogrosides extract containing high content of mogroside V)supplement on fat content,lipid accumulation,colon barrier and gut microbiota in a 38-week HF-HSD mice trial.Results showed that the SG intervention could decrease the weight gain and body fat content,alleviated lipid accumulation,low-grade inflammation and colon barrier injury.SG juice intake was found to increase the antioxidant enzyme activities of serum glutathione peroxidase and liver superoxide dismutase.16S r RNA analysis found that SG could restore the gut microbiota with downregulation of harmful bacteria increased by HF-HSD and enhancement of the abundances of beneficial genus.In particular,SG juice significantly enriched taxonomic family Prevotellaceae and genus Alloprevotella.These results indicated that SG might be a functional additive to prevent disease risk caused by excess fat and sugar diet,and active ingredients resulting to the discrepancy of performance especially on gut microbiota are worthy of in-depth investigation.
基金supported by the National Key Research and Development Program of China(2022YFD1601502 and 2023YFD1200202)the National Natural Science Foundation of China(32272167 and 32341028)+1 种基金the Sichuan Science and Technology Program,China(2022ZDZX0015)the Fundamental Research Funds for the Central Universities,China(SCU2019D013)。
文摘Brassica napus,one of the most important oil crops cultivated globally,is severely impacted by prolonged soil contamination with cadmium(Cd),resulting in decreased yields and poor seed quality.This crop exhibits a high adsorption capacity for Cd,making creating seed resources with low Cd accumulation an essential strategy to alleviate this challenge.To address this issue,we genetically edited BnaNRAMP1 in B.napus by targeting three different exon regions,resulting in new germplasm resources with significant differences in Cd accumulation capacity and unaffected yield.Among these,the mutant K140-22,specifically targeting the 7th exon,is distinguished by its substantially reduced Cd accumulation.Further,enzyme assays of the antioxidant defense system in both roots and shoots of K140-22 revealed its enhanced antioxidant activity,which contributes to elucidating the molecular mechanisms of plant tolerance to heavy metal stress.Remarkably,this mutant also maintained equivalent agronomic traits and seed quality,which highlights its potential as a germplasm resource for rapeseed breeding for low Cd accumulation and elevating rapeseed economic value in Cd-contaminated soil.
文摘There are abundant hydrothermal events within the Dengying Formation dolomite of the Precambrian system in southwest China.Methods including petrography identification,fluid-inclusion observation,in-situ U-Pb dating,and in-situ measurement of rare earth element(REE),etc.are integrated to characterize hydrothermal activity process within the Dengying Formation dolomite.The hydrothermal activity therein can be divided into four stages on the basis of in-situ U-Pb dating results of saddle dolomite cements.The 1st-stage(415.0-400.0 Ma)and 2nd-stage(259.4-248.0 Ma)hydrothermal events are characterized by saddle dolomite filling along the margin of fractures,or filling within dilational breccia and zebra textures.Compared with matrix dolomite and seawater-derived fibrous dolomite,saddle dolomite exhibits obvious negative anomalies of Ce elements.The 3rd-stage(225.6-199.0 Ma)hydrothermal event is represented by galena,sphalerite and other Mississipppi Valley-type(MVT)mineral cements in residual space.The formation of lead-zinc ore is due to the precipitation of metal sulfide caused by the thermo-chemical sulfate reduction(TSR)reaction between hydrothermal fluids and hydrocarbons during the large-scale hydrocarbon charging period.The 4th-stage(130.0-41.0 Ma)hydrothermal event is characterized by quartz and a small amount of fluorite filling the residual pores with dolomites.Quartz and fluorite record the migration of deep high-temperature hydrothermal fluid along early fractures and residual pores.During this period,the hydrothermal fluids result in the heterogeneous structure of bitumen,which is a clear response to high-temperature hydrothermal activity.
基金financially supported by the National Natural Science Foundation of China (Grant No. 42002133)Science Foundation of China University of Petroleum,Beijing No.2462024XKBH009+1 种基金the 2022 AAPG Foundation Grants-in-Aid ProgramChina National Postdoctoral Science Foundation(BX20240425 and 2024M753611)
文摘With the development of unconventional hydrocarbon, how to improve the shale oil and gas recovery become urgent. Therefore hydraulic fracturing becomes the key due to the complicated properties of the reservoirs. The pore structure not only plays an essential role in the formation of complex fracture networks after fracturing but also in resource accumulation mechanism analyses. The lacustrine organicrich shale samples were selected to carry out petrophysical experiments. Scanning Electron Microscopy(SEM) and X-ray Diffraction were performed to elucidate the geology characteristics. MICP, 2D NMR, CT,and N2adsorption were conducted to classify the pore structure types. The contribution of pore structure to oil accumulation and hydrocarbon enrichment was explained through the N2adsorption test on the original and extracted state and 2D NMR. The results show that micropores with diameter less than20 nm are well-developed. The pore structure was divided into three types. Type Ⅰ is characterized by high porosity, lower surface area, and good pore throat connectivity, with free oil existing in large pores,especially lamellation fractures. The dominant nano-pores are spongy organic pores and resources hosted in large pores have been expelled during high thermal evolution. The content of nano-pores(micropores) increases and the pore volume decreases in Type Ⅱ pore structure. In addition, more absorbed oil was enriched. The pore size distribution of type Ⅱ is similar to that of type Ⅰ. However, the maturity and hydrocarbon accumulation is quite different. The oil reserved in large pores was not expelled attributed to the relatively low thermal evolution compared with type Ⅰ. Structural vitrinite was observed through SEM indicating kerogen of type Ⅲ developed in this kind of reservoir while the type of kerogen in pore structure Ⅰ is type Ⅱ. Type Ⅲ pore structure is characterized by the largest surface area,lowest porosity, and almost isolated pores with rarely free oil. Type Ⅰ makes the most contribution to hydrocarbon accumulation and immigration, which shows the best prospect. Of all of these experiments,N2adsorption exhibits the best in characterizing pores in shales due to its high resolution for the assessment of nano-scale pores. MICP and NMR have a better advantage in characterizing pore space of sandstone reservoirs, even tight sandstone reservoirs. 2D NMR plays an essential role in fluid recognition and saturation calculation. CT scanning provides a 3D visualization of reservoir space and directly shows the relationship between pores and throats and the characteristics of fractures. This study hopes to guide experiment selection in pore structure characterization in different reservoirs. This research provides insight into hydrocarbon accumulation of shales and guidance in the exploration and development of unconventional resources, for example for geothermal and CCUS reservoirs.
基金supported by the Guangzhou Marine Geological Survey,China Geological Survey,Guangzhou,China(No.2022C-24-216)financed by the General Project of the Shandong Natural Science Foundation,China(No.ZR2020ME090).
文摘The Shenhu Area in the South China Sea is rich in oil and gas resources and has many vertical gas chimneys,making it an excellent geological environment for hydrate accumulation.This paper examines the geological conditions governing these gas-chimneys.A numerical simulation method based on the partial-equilibrium reaction model of hydrate was applied to simulate the migration of methane gas and the resultant hydrate formation when the gas enters the hydrate stability zone under the seabed through gas-chimneys.The dynamics of this gaschimney hydrate accumulation were analyzed,and the influences of different factors―namely,the fluid supply time,rate,and temperature―on the formation temperature and ultimate distribution of the hydrate reservoir were evaluated.The simulation results indicate that the accumulation of hydrate via gas-chimneys is significantly affected by the temperature of the gas source,the transfer state of the methane gas,and the number of cycles of alternating gas-water invasion.Hydrate accumulation takes shape in an annular or semi-annular distribution pattern divided by fluid state as follows:a two-phase gas-water zone,a three-phase gas-water-hydrate zone,a two-phase water-hydrate zone,and a phase of water passing from the inside to the outside.Formation inclination and reservoir heterogeneity can greatly affect the distribution shape and abundance of the hydrate.A high fluid supply temperature,frequent alternating invasions of gas and water,and long-term pore-water invasion at a high rate can jointly cause a large central hydrate-free zone.In contrast,a long-term supply shutdown during the alternating gas-water invasion process,and a high gas rate with a low water rate in the gas-dominant invasion stage,foster the accumulation of hydrate in great abundance and with considerable thickness.The results of this study can help us understand the accumulation of hydrate through gas chimneys in the Shenhu Area.
基金the National Natural Science Foundation of China(NSFC No.32360309)。
文摘Bauxite mining will bring huge economic benefit,but it also faces the risk of environmental pollution.Metal pollution problem has been widely concerned in bauxite tailing areas.Biodiversity indices,metal concentrations of moss crusts,and soil contamination indices in Wachangping bauxite tailing areas in Guizhou Province,China were measured and analyzed.In a total of 40 species belonging to 19 genera and 12 families of moss in the study areas,Ditrichum flexicaule(Schwaegr.)Hamp.(DF),Oxystegus cylindricus(Brid.)Hilp.(OC),and Ditrichum brevidens Nog.(DB)are the dominant moss crusts.Moss species diversity in different habitats has a certain regularity:waste residues area<waste rocks area<ore stockpile area<slope shrub area<shrub area by gutter<slope shrub herbaceous area.Sorenson diversity index(β)of moss species is influenced by microenvironment and substrate.Concentrations of Al,Mg,Ca,Fe,K,and Ti are the largest in DB(2,990 to 73,210 mg kg^(-1)),followed by those in DF(2,900 to 61,890 mg kg^(-1)),and are the smallest in OC(690 to 32,240 mg kg^(-1)),which show that the three moss crusts have different bioaccumulation capacities.Metal contents in underlying soils of moss crusts are higher than the background levels.Bioaccumulation factor(BAF)of Al,Mg,Ca,Fe,and K in three moss crusts are decreased in the following order:DB>DF>OC.Single factor pollution index(Ps)and Nemero comprehensive pollution index(Pc)of six metal are much greater than 3,and the index of geoaccumulation(Igeo)(1geo<5)reveals that the soil environment is at moderately to seriously contaminated levels.Principal components analysis(PCA)shows that there is no significant correlation between p H value,and metal contents(Al,Mg,Fe,K and Ti),soil temperature(ST)and metal contents(Al,Mg,Fe,K and Ti).Soil humidity(SH)is negatively correlated with metal contents(Al,Mg,Fe,K and Ti).These three environmental factors have little effect on the distribution of metal.Result also reflects that DB moss is readily able to both tolerate and accumulate metal,which makes it a suitable bioindicator of multiple metal contamination in Wachangping bauxite tailing areas.
基金supported by the Key Project of the National Natural Science Foundation of China(No.42230711)。
文摘Aluminium(Al)toxicity is one of the key factors limiting crop output in acidic soils,but until now little has been known about how Al is regulated transcriptionally in plants.This study identified Arabidopsis NAC transcription factor ANAC050 in the regulation of Al tolerance.ANAC050 was located in the nucleus and displayed constitutive expression in the silique,flower,leaf,stem,and root,despite the fact that Al stress decreased its expression and protein accumulation.When compared with the Columbia ecotype wild-type,anac050 mutants that lacked function of ANAC050 exhibited Al sensitivity phenotype,while transgenic lines that overexpressed ANAC050 showed an Al-resistant phenotype,indicating the favorable influence of ANAC050 on preserving Al tolerance in plants.Further analysis indicated that anac050 mutants accumulated more Al in roots,implying that ANAC050 may confer a potential operation of an Al exclusion mechanism.Interestingly,anac050 mutants had down-regulated the expression of the genes encoding MULTIDRUG AND TOXIC COMPOUND EXTRUSION(MATE)and AL-ACTIVATED MALATE TRANSPORTER(ALMT1),which were involved in the secretion of citrate and malate,even though there was no evidence of a direct interaction between them,suggesting ANAC050 may mediate the secretion of citrate and malate indirectly.Together with the decreased hemicellulose content,lower Al content was also discovered in root cell walls and hemicelluloses of anac050 mutants,pointing to a potential interaction between ANAC017 and XYLOGLUCAN ENDOTRANSGLUCOSYLASE/HYDROLASE(XTH).Although there was no evidence of a direct interaction between ANAC050 and XTH31,it is worth mentioning that the expression of XTH31,which is essential for xyloglucan modification,was down-regulated in anac050 mutants irrespective of the amount of Al given.In conclusion,our findings showed that ANAC050 contributed to Al resistance by indirect control of the release of organic acids and the accumulation of cell wall hemicelluloses.
