INTRODUCTION Contemporary human living environments present complex and pervasive health risks,and environmental health challenges are becoming increasingly prominent.These risks encompass diverse domains,such as chem...INTRODUCTION Contemporary human living environments present complex and pervasive health risks,and environmental health challenges are becoming increasingly prominent.These risks encompass diverse domains,such as chemical factors(e.g.,heavy metals,nanomaterials,per-and polyfluoroalkyl substances),physical factors(e.g.,noise,radiation,and extreme weather)biological factors(e.g.,pathogenic microorganisms and parasites),natural disasters(e.g.,earthquakes and floods),and anthropogenic incidents(e.g.,chemical spills,fires,and explosions).展开更多
Phosphorus(P)is a nonrenewable resource and a critical element for plant growth that plays an important role in improving crop yield.Excessive P fertilizer application is widespread in agricultural production,which no...Phosphorus(P)is a nonrenewable resource and a critical element for plant growth that plays an important role in improving crop yield.Excessive P fertilizer application is widespread in agricultural production,which not only wastes phosphate resources but also causes P accumulation and groundwater pollution.Here,we hypothesized that the apparent P balance of a crop system could be used as an indicator for identifying the critical P input in order to obtain a high yield with high phosphorus use efficiency(PUE).A 12-year field experiment with P fertilization rates of 0,45,90,135,180,and 225 kg P_(2)O_(5)ha^(-1)was conducted to determine the crop yield,PUE,and soil Olsen-P value response to P balance,and to optimize the P input.Annual yield stagnation occurred when the P fertilizer application exceeded a certain level,and high yield and PUE levels were achieved with annual P fertilizer application rates of 90-135 kg P_(2)O_(5)ha^(-1).A critical P balance range of 2.15-4.45 kg P ha^(-1)was recommended to achieve optimum yield with minimal environmental risk.The critical P input range estimated from the P balance was 95.7-101 kg P_(2)O_(5)ha^(-1),which improved relative yield(>90%)and PUE(90.0-94.9%).In addition,the P input-output balance helps in assessing future changes in Olsen-P values,which increased by 4.07 mg kg^(-1)of P for every 100 kg of P surplus.Overall,the P balance can be used as a critical indicator for P management in agriculture,providing a robust reference for limiting P excess and developing a more productive,efficient and environmentally friendly P fertilizer management strategy.展开更多
Objective To assess relationships between cold spells and genitourinary hospitalization risk.Methods Hospitalization records for genitourinary system diseases(GUDs)from 16 districts in Beijing(2013–2018)were analyzed...Objective To assess relationships between cold spells and genitourinary hospitalization risk.Methods Hospitalization records for genitourinary system diseases(GUDs)from 16 districts in Beijing(2013–2018)were analyzed.Cold spells were defined based on varying intensity thresholds.A two-stage analytical method was employed:first,generalized linear models assessed district-specific associations between cold spells and hospitalizations;second,random-effects meta-analysis aggregated the districtlevel results.Subgroup analyses were performed by admission type(emergency vs.outpatient),age,and sex.Results A total of 271,579 GUD-related hospitalizations were recorded.Cold spells(p1day2,daily mean temperature below the 1st percentiles of the daily mean temperature distribution from January 1,2013,to December 31,2018,lasting for two or more consecutive days)were linked to a significant rise in hospitalization risks:1.43(95%CI:1.32–1.56)for all GUDs,1.35(95%CI:1.23–1.49)for urinary system diseases,and 1.46(95%CI:1.28–1.67)for renal failure,when compared to non-cold spell days.Emergency admissions showed higher risk increases than outpatient admissions.Conclusion Extreme cold spells significantly elevate hospitalization risks for GUDs.This highlights the urgent need for targeted public health interventions to mitigate cold-related health impacts,especially for vulnerable populations.展开更多
Personal care products(PCPs)are a class of emerging pollutants that have attracted public concern owing to their harmful effects on humans and the environment.Biomonitoring data is valuable for insight the levels of P...Personal care products(PCPs)are a class of emerging pollutants that have attracted public concern owing to their harmful effects on humans and the environment.Biomonitoring data is valuable for insight the levels of PCPs in the human body and can be crucial for identifying potential health hazards.To gain a better understanding of timely exposure profiles and health risk of reproductive-age population to PCPs,we determined six parabens,six benzophenone-type ultraviolet filters,and three disinfectants in 256 urine samples collected from young adults aged 18-44 years in Beijing,China.The urinary levels of benzophenone-3(BP-3)and 4-hydroxybenzophenone(4-OHBP)were significantly higher in summer compared to winter,suggesting these compounds have different seasonal usage patterns.Moreover,the total concentration of 15 PCPs in female was 430 ng/mL,approximately two times higher than that in male.P-chloro-m-xylenol(PCMX),as a new type of antibacterial agent,has the greatest level among all target analytes,indicating the increasingly use of this antibacterial alternative recently.Five potential influencing factors that lead to the elevated exposure level of PCPs were identified.Over 19%of the target population had a high hazard index value(greater than 1)which was attributed to exposure to propyl paraben(PrP),benzophenone-1(BP-1),BP-3 and PCMX,indicating that PCPs may pose a relatively high exposure risk at environmental levels that should be a cause for concern.展开更多
Adjustment of the sowing date is a widely used measure in rice production for adapting to high-temperature conditions.However,the impact of a delayed sowing date(DS)on rice quality may vary by variety and ecological c...Adjustment of the sowing date is a widely used measure in rice production for adapting to high-temperature conditions.However,the impact of a delayed sowing date(DS)on rice quality may vary by variety and ecological conditions.In this study,we conducted experiments using four different sowing dates,the conventional sowing date 1(CS1),CS2(10 d later than CS1),DS1(30 d later than CS1),and DS2(30 d later than CS2),and three rice varieties,i.e.,Yixiangyou 2115,Fyou 498,and Chuanyou 6203.This experiment was conducted at four sites in the Sichuan Basin in 2018 and 2019 to evaluate the infuence of DS on the pasting properties of rice,which are a proxy for the eating and cooking quality(ECQ).In DS1 and DS2,the rice had a signifcantly greater amylose content(AC)but a lower protein content(PC),peak viscosity(PKV),cool paste viscosity(CPV),and hot paste viscosity(HPV)than in CS1 and CS2.Moreover,except for CS2 and DS1 in 2018,DS1 and DS2 led to 2.15-11.19%reductions in breakdown viscosity(BDV)and 23.46-108.47%increases in setback viscosity(SBV).However,the infuence of DS on rice pasting properties varied by study site and rice variety.In 2019,DS1 and DS2 led to BDV reductions of 2.35-9.33,2.61-8.61,10.03-17.78,and 2.06-8.93%,and SBV increases of 2.32-60.93,63.74-144.24,55.46-91.63,and-8.28-65.37%at the Dayi,Anzhou,Nanbu,and Shehong(except for SBV in CS2 and DS1)sites,respectively.DS resulted in greater reductions in PKV,HPV,CPV,and BDV and greater increases in the AC and SBV for Yixiangyou 2115 than for Chuanyou 6203 and Fyou 498.The correlation analysis indicated that PKV and HPV were signifcantly and positively related to the mean,maximum,and minimum temperatures after heading.These temperatures must be greater than 25.9,31.2,and 22.3℃,respectively,to increase the relative BDV and reduce the relative SBV of rice,thereby enhancing ECQ.In conclusion,DS might contribute to a signifcant deterioration in ECQ in machine-transplanted rice in the Sichuan Basin.A mean temperature above 25.9℃ after heading is required to improve the ECQ of rice.展开更多
To explore the multicenter characteristics of endocrine-like phthalate esters(PAEs)in household dust and propose effective control strategies for global indoor public health.An on-site observational investigation was ...To explore the multicenter characteristics of endocrine-like phthalate esters(PAEs)in household dust and propose effective control strategies for global indoor public health.An on-site observational investigation was conducted in nine Chinese cities from 2018 to 2019.A total of 246 household dust sampleswere collected and analyzed for ten PAE congeners using Gas Chromatography-Mass Spectrometry(GC-MS).Questionnaires were used to gather information on building conditions,indoor behaviors,and ventilation habits.In residential dust from the nine cities,the total concentrations of the ten PAE congeners(PAEs)ranged from 0.921 to 29097.297μg/g.Dicyclohexyl phthalate(DCHP)and di(2-ethylhexyl)phthalate(DEHP)were the dominant congeners inPAEs.Childhood exposure to PAEs through dust ingestion was four orders of magnitude higher than through inhalation,with a carcinogenic risk of 5.47×10^(−6) for DEHP exposure in household dust.HigherPAEs concentrations were associated with higher temperature,double glazing,wall paint usage,television and computer use,and indoor plant growth.This multicenter on-site investigation confirmed PAE pollution characteristics and uncovered the inacceptable risk of daily DEHP exposure in household dust under real living conditions.Effective mitigation measures based on household-related information,residential characteristics,decoration materials,and lifestyle should be taken to build a healthy household environment.展开更多
Objective This study aimed to evaluate the relationships of white blood cell(WBC)count,platelet(PLT)count,and PLT-to-WBC ratio(PWR)with muscle mass in Chinese older adults.Methods This cross-sectional analysis involve...Objective This study aimed to evaluate the relationships of white blood cell(WBC)count,platelet(PLT)count,and PLT-to-WBC ratio(PWR)with muscle mass in Chinese older adults.Methods This cross-sectional analysis involved 4,033 Chinese older adults aged≥65 years from the Healthy Ageing and Biomarkers Cohort Study.Muscle mass and total skeletal muscle mass index(TSMI)were measured by bioelectric impedance analysis.WBC,PLT,and PWR were measured using standard methods.Multivariate linear regression was used to examine the associations of WBC count,PLT count,and PWR with TSMI.Results High WBC count,PLT count,and PWR were associated with low TSMI,with coefficients of-0.0091(95%confidence interval[CI]:-0.0142 to-0.0041),-0.0119(95%CI:-0.0170 to-0.0068),and-0.0051(95%CI:-0.0102 to-0.0001).The associations between the three inflammatory indices and TSMI were linear.Stratified analyses indicated that the relationship between inflammatory markers and TSMI was more evident in male participants and in individuals aged<80 years than in their counterparts.Conclusion Elevated WBC count,PLT count,and PWR correlated with muscle mass loss.This study highlights the importance of regular monitoring of inflammatory markers as a potential strategy for the screening and management of sarcopenia in older adults.展开更多
Pacing-induced cardiomyopathy (PICM) resultsf rom the detrimental effect of frequent right ventricular pacing.^([1]) The diagnosis relies on a combination of pacing-associated ventricular dyschrony manifested with ECG...Pacing-induced cardiomyopathy (PICM) resultsf rom the detrimental effect of frequent right ventricular pacing.^([1]) The diagnosis relies on a combination of pacing-associated ventricular dyschrony manifested with ECG wide LBBB-pattern QRS duration and clinical assessment, imaging studies. Conduction system pacing (CSP), such as His bundle pacing (HBP)and left bundle branch pacing (LBBP), may help to prevent PICM,^([2]) but the criteria for optimal patient selection remain inadequately defined.展开更多
Granite residual soil slope is often destroyed,which poses great threats to Rong County in southeastern Guangxi,China.Heavy rainfall and fissures are the major triggering and internal factors.The fissure that controls...Granite residual soil slope is often destroyed,which poses great threats to Rong County in southeastern Guangxi,China.Heavy rainfall and fissures are the major triggering and internal factors.The fissure that controls the slope stability and the associated failure mechanisms remain unclear.The purpose of this study was to identify the controlling fissures through field investigation,elucidate the effect of its position,and analyze the failure process and hydrological response of residual soil slope through artificial flume model tests.The results comprised five aspects.(1)Surface weathering and unloading fissures could affect slope stability.(2)The failure processes with different fissure positions exhibited inconsistent characteristics.(3)The volume moisture content(VMC)had the most direct response at the fissure tip.The corresponding infiltration rate was the highest.The response time of pore water pressure(PWP)was longer than that of VMC.Fluctuations in PWP were associated with VMC and changes in the soil microstructure due to local deformation.(4)Slope failure was accompanied by serious soil erosion.This could be attributed to the infiltration direction and the interaction between soil and water.(5)Fissured soil slopes experienced five similar failure processes:sheet erosion and partial failure of the slope foot,occurrence of preferential flow and enlargement of the sliding area,creep deformation and tension fissure emergence,block sliding and gully erosion,and flow-slip.展开更多
Background Diarrhea remains a major health concern in both young animals and humans.Prevotella spp.,a dominant commensal genus in the healthy porcine gut,becomes increasingly abundant following weaning,suggesting a po...Background Diarrhea remains a major health concern in both young animals and humans.Prevotella spp.,a dominant commensal genus in the healthy porcine gut,becomes increasingly abundant following weaning,suggesting a potential role during this critical transitional period.However,its involvement in post-weaning diarrhea remains poorly understood.Here,we aim to elucidate the role and underlying mechanisms of Prevotella in alleviating diarrhea in weaned piglets.Results To model unsanitary housing conditions,piglets were housed in uncleaned pens containing residual fecal matter from previous occupants and exposed to cold stress by maintaining the ambient temperature at 19℃,below the optimal 28℃.Under these conditions,piglets were orally administered either a blank medium(CON,n=10×2)or Prevotella copri at 1×10^(8)CFU(Pc,n=10×2)on d 1,3,and 5.After 28 d,cold stress induced a diarrhea incidence of 33.45%in the CON group,while P.copri supplementation significantly reduced the diarrhea rate to 19.73%.Treatment with P.copri markedly improved intestinal morphology in the small intestine,decreased serum levels of lipopolysaccharide(LPS)and intestinal fatty acid-binding protein(i-FABP),and enhanced total antioxidant capacity(T-AOC)and catalase(CAT)activity.Quantitative PCR and 16S rRNA gene sequencing revealed that P.copri significantly increased the colonic abundance of Prevotella,reshaping both the composition and functional profile of the gut microbiota.Moreover,P.copri enhanced the modularity and robustness of microbial ecological networks.Untargeted metabolomic profiling of colonic contents revealed a significant enrichment of metabolites involved in the arachidonic acid pathway following P.copri supplementation.In parallel,untargeted metabolomics of P.copri culture supernatants identified differential metabolic pathways including metabolic pathways,biosynthesis of secondary metabolites,and biosynthesis of antibiotics.In vitro assays demonstrated that P.copri-derived metabolites inhibited the growth of three common porcine intestinal pathogens.Furthermore,both P.copri metabolites and arachidonic acid enhanced intestinal barrier integrity and suppressed TNF-α-induced inflammation and apoptosis in Caco-2 cells through activation of the AHR–Nrf2 signaling pathway.Conclusions These findings highlight the role of P.copri in maintaining gut homeostasis and provide new insights into microbiota-based interventions for early-life intestinal disorders.展开更多
Populus species,important economic species combining rapid growth with broad ecological adaptability,play a critical role in sustainable forestry and bioenergy production.In this study,we performed whole-genome resequ...Populus species,important economic species combining rapid growth with broad ecological adaptability,play a critical role in sustainable forestry and bioenergy production.In this study,we performed whole-genome resequencing of 707 individuals from a full-sib family to develop comprehensive single nucleotide polymorphism(SNP)markers and constructed a high-density genetic linkage map of 19 linkage groups.The total genetic length of the map reached 3623.65 cM with an average marker interval of 0.34 cM.By integrating multidimensional phenotypic data,89 quantitative trait loci(QTL)associated with growth,wood physical and chemical properties,disease resistance,and leaf morphology traits were identified,with logarithm of odds(LOD)scores ranging from 3.13 to 21.72 Notably,pleiotropic analysis revealed significant colocaliza and phenotypic variance explained between 1.7% and 11.6%.-tion hotspots on chromosomes LG1,LG5,LG6,LG8,and LG14,with epistatic interaction network analysis confirming genetic basis of coordinated regulation across multiple traits.Functional annotation of 207 candidate genes showed that R2R3-MYB and bHLH transcription factors and pyruvate kinase-encoding genes were significantly enriched,suggesting crucial roles in lignin biosynthesis and carbon metabolic pathways.Allelic effect analysis indicated that the frequency of favorable alleles associated with target traits ranged from 0.20 to 0.55.Incorporation of QTL-derived favorable alleles as random effects into Bayesian-based genomic selection models led to an increase in prediction accuracy ranging from 1% to 21%,with Bayesian ridge regression as the best predictive model.This study provides valuable genomic resources and genetic insights for deciphering complex trait architecture and advancing molecular breeding in poplar.展开更多
The Damoqujia gold deposit,discovered recently and located in the north of Zhaoping fault zone,is a large altered rock type deposit.In this paper,we report the preliminary research results of the fluid inclusions and ...The Damoqujia gold deposit,discovered recently and located in the north of Zhaoping fault zone,is a large altered rock type deposit.In this paper,we report the preliminary research results of the fluid inclusions and discuss its metallogenic implications. The homogenization temperatures of fluid inclusions fall into four ranges:310～350℃,230～270℃,160～200℃and 110～150℃; corresponding to the four stages of hydrothermal ore-forming processes:coarse grain pyrite-milk white quartz stage(Ⅰ),smoky gray Au-bearing quartz-fine grain pyrite stage(Ⅱ),Au-bearing polymetallic sulfide-quartz stage(Ⅲ),and quartz-carbonate stage(Ⅳ). Ore-forming fluid is with low salinity and low density,ranging from 1.4 Wt_(NaCl)% to 13.6 Wt_(NaCl)% and from 0.48g/cm^3 to 1.03g/cm^3 respectively.The inclusions are dominated by H_2O and CO_2 in gaseous compositions,and Na^+ and K^+ in positive ions,SO_4^(2-)and Cl^- in negative ions of liquid compositions.Au-S complex is the major form for transportation of gold.The pressure varied from 260MPa to 340MPa during the formation of CO_2-bearing inclusions at the early mineralization;the fluids are rich in SO_4^(2-)and Na^+.The pressure is 26-49×10~5 Pa during the formation of the aqueous salt inclusions in late mineralization,the inclusions are rich in CI^-(F^-), Na^+.δ^(18)O_(qurrtz)is 10.64～12.68%o,and the correspondingδ^(18)O_(H_2)O andδD is-5.44～6.47‰and-95.52～-106.48‰respectively.Based on the studies about compositions and hydrogen and oxygen isotopes of inclusions,it is evidenced that ore-forming fluid is magmatic hydrothermal fluid in early period,but affected by meteoric water in late.展开更多
ObjectiveThis study aims to characterize the occurrences and interior structural features of botryoidal structures from the Sinian Dengying Formation in the Sichuan Basin of Southwestern China, and to shed light on th...ObjectiveThis study aims to characterize the occurrences and interior structural features of botryoidal structures from the Sinian Dengying Formation in the Sichuan Basin of Southwestern China, and to shed light on their formation mechanism.展开更多
During the Cambrian, gypsum-bearing evaporites formed in the Sichuan Basin, SW China. These rocks are important for oil and gas sealing, but details of their distribution and origin are not well established. This stud...During the Cambrian, gypsum-bearing evaporites formed in the Sichuan Basin, SW China. These rocks are important for oil and gas sealing, but details of their distribution and origin are not well established. This study examines the regional distribution and origin of the gypsum-bearing evaporites using a comprehensive analysis of drilling data from 34 wells, 5 measured cross-sections in the basin and surrounding area, and 96 maps of area-survey data. Results show that in the stratigraphic succession, the gypsum-bearing evaporites occur mainly in the Lower Cambrian Longwangmiao Formation, the Middle Cambrian Douposi Formation, and the Middle-Upper Cambrian Xixiangchi Group. Geographically, the rocks are found mainly in the southeastern part of the basin, and the distribution of deposits shows an overall SW-NE trend. The sedimentary environments for evaporite formation were evaporative lagoon and inter-platform basin in a platform setting. Gypsum was generated by the underwater concentration of sea water in a strongly evaporative environment. Both an evaporative restricted platform and a mixeddeposition restricted platform model appear to be applicable to the development of gypsum in the Sichuan Basin. The gypsum-bearing evaporites with the best sealing capacity are located mostly in the southeastern part of the basin. These constraints can be applied directly to regional exploration, and have implications for the regional paleogeography and paleoclimate.展开更多
Heavy-duty machine tools are composed of many subsystems with different functions,and their reliability is governed by the reliabilities of these subsystems.It is important to rank the weaknesses of subsystems and ide...Heavy-duty machine tools are composed of many subsystems with different functions,and their reliability is governed by the reliabilities of these subsystems.It is important to rank the weaknesses of subsystems and identify the weakest subsystem to optimize products and improve their reliabilities.However,traditional ranking methods based on failure mode effect and critical analysis(FMECA)does not consider the complex maintenance of products.Herein,a weakness ranking method for the subsystems of heavy-duty machine tools is proposed based on generalized FMECA information.In this method,eight reliability indexes,including maintainability and maintenance cost,are considered in the generalized FMECA information.Subsequently,the cognition best worst method is used to calculate the weight of each screened index,and the weaknesses of the subsystems are ranked using a technique for order preference by similarity to an ideal solution.Finally,based on the failure data collected from certain domestic heavy-duty horizontal lathes,the weakness ranking result of the subsystems is obtained to verify the effectiveness of the proposed method.An improved weakness ranking method that can comprehensively analyze and identify weak subsystems is proposed herein for designing and improving the reliability of complex electromechanical products.展开更多
Using the daily maximum and minimum temperature dataset from 128 stations from 1960 to 2004 in Northwest China,daily extreme high temperature(EHT)and extreme low temperature(ELT)thresholds were deter-mined by centesim...Using the daily maximum and minimum temperature dataset from 128 stations from 1960 to 2004 in Northwest China,daily extreme high temperature(EHT)and extreme low temperature(ELT)thresholds were deter-mined by centesimal method for different stations at first,then yearly EHT and ELT events were counted up in differ-ent stations,and the characteristics of their spatio-temporal distribution were diagnosed at last.The study drew follow-ing conclusions:1)The consistent anomaly distribution characteristic was the most important mode of the EHT and ELT events in Northwest China.2)The spatial distribution of the EHT and ELT events can be divided into five sub-regions,namely,the north of Qinghai and west of Gansu,the north of Xinjiang,the south of Xinjiang,the east of Northwest China and the south of Qinghai.3)The EHT events showed remarkable increasing trend in all of five sub-regions,but only in the north of Qinghai and west of Gansu area,sudden change phenomenon occurred;the ELT events showed decreasing trend in all of five sub-regions,and sudden change phenomenon occurred in Northwest China except for south of Qinghai.4)In all of five sub-regions the EHT events showed remarkable 12-14yr period os-cillation,and the ELT event showed significant 13-15yr and 7-8yr period oscillation.5)The EHT and ELT events displayed remarkable positive and negative responses to regional warming of Northwest China respectively.展开更多
According to the satellite remote sensing monthly mean sea surface temperature data from 1998 to 2002, it is shown that, the Sulu Sea is dominated by a cold eddy both in summer and winter. A coupled single-layer/two-l...According to the satellite remote sensing monthly mean sea surface temperature data from 1998 to 2002, it is shown that, the Sulu Sea is dominated by a cold eddy both in summer and winter. A coupled single-layer/two-layer model is employed here to study the summery and wintry characteristics and dynamic mechanism of the upper circulation in the Sulu Sea. According to the numerical experiments, it is found that, due to the local monsoon stress curl, the upper circulation in the Sulu Sea is dominated by a weak anticyclonic eddy in summer and a strong cyclonic eddy in winter. Once there is a large outflow via the Sibutu Passage flowing out of the Sulu Sea in summer, the upper circulation in the Sulu Sea may be dominated by a cyclonic eddy instead of the normal anticyclonic one. Moreover, in summer, the water exchange between the Sulu Sea and South China Sea via the Mindoro and Balabac Straits might have some effect on the separation position and strength of the northward western boundary current next to the Indo-China Peninsula in the southern South China Sea.展开更多
We measured the target strength （TS） of three commercial fish species： whitespotted spinefoot （Siganus canaliculatus）, black porgy （Acanthopagrus schlegelii）, and creek red bream （Lutjanus argentimaculatus）, ...We measured the target strength （TS） of three commercial fish species： whitespotted spinefoot （Siganus canaliculatus）, black porgy （Acanthopagrus schlegelii）, and creek red bream （Lutjanus argentimaculatus）, in the South China Sea. The TS of caged or tethered fish （n=76 total） was measured using a Simrad EY60 portable scientific echosounder at 120 kHz. We evaluated the relationship between TS and total length （TL, cm） for the three species. This is the first attempt to use split-beam acoustics to measure single-fish TS in the South China Sea by Chinese researchers. Our results will improve the accuracy and precision of acoustic abundance estimates of commercially important species and fi.trther the development of underwater acoustic survey techniques in fisheries in the South China Sea.展开更多
The solubility and sorption of oil by uncontaminated clay loam and silt loam soils were studied from water and cosolvent/water solutions using batch techniques. The data obtained from the dissolution and sorption expe...The solubility and sorption of oil by uncontaminated clay loam and silt loam soils were studied from water and cosolvent/water solutions using batch techniques. The data obtained from the dissolution and sorption experiments were used to evaluate the applicability of the cosolvent theory to oil as a complex mixture. Aqueous solubility and soil-water distribution coeffcients (Kd,w, L/kg) were estimated by extrapolating from cosolvent data, with a log-linear cosolvency model, to the volume fraction of cosolve...展开更多
Taking the tight oil of the Zhongnan sag in the Ordos Basin,Jimusar sag in the Junggar Basin and Qingxi sag in the Jiuquan Basin as study objects,based on field survey,dissection of tight oil reservoirs,sample test,mo...Taking the tight oil of the Zhongnan sag in the Ordos Basin,Jimusar sag in the Junggar Basin and Qingxi sag in the Jiuquan Basin as study objects,based on field survey,dissection of tight oil reservoirs,sample test,modeling experiment and comprehensive analysis,this study reveals that the tight oil accumulates at start-up pressure,advances under differential pressure,diffuses at alternating fast and low speeds,charges in stepped large area and migrates rapidly through fractures,and enriches in dominant fractures and pores.The root cause of ladder-like charge is the multiple scales of pores.The widespread source rock with high hydrocarbon generation intensity is the material basis for tight oil enrichment;the dominant source reservoir assemblage is the basic unit for tight oil enrichment;fractures and beddings are conducive to local rapid migration of tight oil;fractures and pores work together to control the enrichment of tight oil.Two typical accumulation models of tight oil are established,namely"source reservoir in coexistence,four optimal factors controlling enrichment around central area,and large-scale continuous distribution"for a large freshwater lake clastic rock basin and"source reservoir integration,four optimal factors controlling enrichment,central area distribution,small in size but high in enrichment degree"for a small saline lake diamictite depression.展开更多
基金supported by the commissioned project of the Department of Health and Immunization Planning under the National Disease Control and Prevention Administration(No.BX2024100800015)The preliminary study project on standardization of the Chinese Center for Disease Control and Prevention(No.BZ2025-Q155)The National Natural Science Foundation of China(No.82404299).
文摘INTRODUCTION Contemporary human living environments present complex and pervasive health risks,and environmental health challenges are becoming increasingly prominent.These risks encompass diverse domains,such as chemical factors(e.g.,heavy metals,nanomaterials,per-and polyfluoroalkyl substances),physical factors(e.g.,noise,radiation,and extreme weather)biological factors(e.g.,pathogenic microorganisms and parasites),natural disasters(e.g.,earthquakes and floods),and anthropogenic incidents(e.g.,chemical spills,fires,and explosions).
基金This study was funded by the National Key Research and Development Program of China(2021YFD1700900).
文摘Phosphorus(P)is a nonrenewable resource and a critical element for plant growth that plays an important role in improving crop yield.Excessive P fertilizer application is widespread in agricultural production,which not only wastes phosphate resources but also causes P accumulation and groundwater pollution.Here,we hypothesized that the apparent P balance of a crop system could be used as an indicator for identifying the critical P input in order to obtain a high yield with high phosphorus use efficiency(PUE).A 12-year field experiment with P fertilization rates of 0,45,90,135,180,and 225 kg P_(2)O_(5)ha^(-1)was conducted to determine the crop yield,PUE,and soil Olsen-P value response to P balance,and to optimize the P input.Annual yield stagnation occurred when the P fertilizer application exceeded a certain level,and high yield and PUE levels were achieved with annual P fertilizer application rates of 90-135 kg P_(2)O_(5)ha^(-1).A critical P balance range of 2.15-4.45 kg P ha^(-1)was recommended to achieve optimum yield with minimal environmental risk.The critical P input range estimated from the P balance was 95.7-101 kg P_(2)O_(5)ha^(-1),which improved relative yield(>90%)and PUE(90.0-94.9%).In addition,the P input-output balance helps in assessing future changes in Olsen-P values,which increased by 4.07 mg kg^(-1)of P for every 100 kg of P surplus.Overall,the P balance can be used as a critical indicator for P management in agriculture,providing a robust reference for limiting P excess and developing a more productive,efficient and environmentally friendly P fertilizer management strategy.
基金supported by the National Natural Science Foundation of China(Grant Nos.92043301,41907367,41961134033)the National High-level Talents Special Support Plan of China for Young Talents.
文摘Objective To assess relationships between cold spells and genitourinary hospitalization risk.Methods Hospitalization records for genitourinary system diseases(GUDs)from 16 districts in Beijing(2013–2018)were analyzed.Cold spells were defined based on varying intensity thresholds.A two-stage analytical method was employed:first,generalized linear models assessed district-specific associations between cold spells and hospitalizations;second,random-effects meta-analysis aggregated the districtlevel results.Subgroup analyses were performed by admission type(emergency vs.outpatient),age,and sex.Results A total of 271,579 GUD-related hospitalizations were recorded.Cold spells(p1day2,daily mean temperature below the 1st percentiles of the daily mean temperature distribution from January 1,2013,to December 31,2018,lasting for two or more consecutive days)were linked to a significant rise in hospitalization risks:1.43(95%CI:1.32–1.56)for all GUDs,1.35(95%CI:1.23–1.49)for urinary system diseases,and 1.46(95%CI:1.28–1.67)for renal failure,when compared to non-cold spell days.Emergency admissions showed higher risk increases than outpatient admissions.Conclusion Extreme cold spells significantly elevate hospitalization risks for GUDs.This highlights the urgent need for targeted public health interventions to mitigate cold-related health impacts,especially for vulnerable populations.
基金supported by the National Natural Science Foundation of China (No.22106154).
文摘Personal care products(PCPs)are a class of emerging pollutants that have attracted public concern owing to their harmful effects on humans and the environment.Biomonitoring data is valuable for insight the levels of PCPs in the human body and can be crucial for identifying potential health hazards.To gain a better understanding of timely exposure profiles and health risk of reproductive-age population to PCPs,we determined six parabens,six benzophenone-type ultraviolet filters,and three disinfectants in 256 urine samples collected from young adults aged 18-44 years in Beijing,China.The urinary levels of benzophenone-3(BP-3)and 4-hydroxybenzophenone(4-OHBP)were significantly higher in summer compared to winter,suggesting these compounds have different seasonal usage patterns.Moreover,the total concentration of 15 PCPs in female was 430 ng/mL,approximately two times higher than that in male.P-chloro-m-xylenol(PCMX),as a new type of antibacterial agent,has the greatest level among all target analytes,indicating the increasingly use of this antibacterial alternative recently.Five potential influencing factors that lead to the elevated exposure level of PCPs were identified.Over 19%of the target population had a high hazard index value(greater than 1)which was attributed to exposure to propyl paraben(PrP),benzophenone-1(BP-1),BP-3 and PCMX,indicating that PCPs may pose a relatively high exposure risk at environmental levels that should be a cause for concern.
基金supported by the National Natural Science Foundation of China(U20A2022 and 32372217)the National Key Research and Development Program of China(2022YFD2300700)the Free Exploration Program of State Key Laboratory of Crop Gene Exploration and Utilization in Sichuan Basin,China(SKL-ZY202216)。
文摘Adjustment of the sowing date is a widely used measure in rice production for adapting to high-temperature conditions.However,the impact of a delayed sowing date(DS)on rice quality may vary by variety and ecological conditions.In this study,we conducted experiments using four different sowing dates,the conventional sowing date 1(CS1),CS2(10 d later than CS1),DS1(30 d later than CS1),and DS2(30 d later than CS2),and three rice varieties,i.e.,Yixiangyou 2115,Fyou 498,and Chuanyou 6203.This experiment was conducted at four sites in the Sichuan Basin in 2018 and 2019 to evaluate the infuence of DS on the pasting properties of rice,which are a proxy for the eating and cooking quality(ECQ).In DS1 and DS2,the rice had a signifcantly greater amylose content(AC)but a lower protein content(PC),peak viscosity(PKV),cool paste viscosity(CPV),and hot paste viscosity(HPV)than in CS1 and CS2.Moreover,except for CS2 and DS1 in 2018,DS1 and DS2 led to 2.15-11.19%reductions in breakdown viscosity(BDV)and 23.46-108.47%increases in setback viscosity(SBV).However,the infuence of DS on rice pasting properties varied by study site and rice variety.In 2019,DS1 and DS2 led to BDV reductions of 2.35-9.33,2.61-8.61,10.03-17.78,and 2.06-8.93%,and SBV increases of 2.32-60.93,63.74-144.24,55.46-91.63,and-8.28-65.37%at the Dayi,Anzhou,Nanbu,and Shehong(except for SBV in CS2 and DS1)sites,respectively.DS resulted in greater reductions in PKV,HPV,CPV,and BDV and greater increases in the AC and SBV for Yixiangyou 2115 than for Chuanyou 6203 and Fyou 498.The correlation analysis indicated that PKV and HPV were signifcantly and positively related to the mean,maximum,and minimum temperatures after heading.These temperatures must be greater than 25.9,31.2,and 22.3℃,respectively,to increase the relative BDV and reduce the relative SBV of rice,thereby enhancing ECQ.In conclusion,DS might contribute to a signifcant deterioration in ECQ in machine-transplanted rice in the Sichuan Basin.A mean temperature above 25.9℃ after heading is required to improve the ECQ of rice.
基金supported by the National Natural Science Foundation of China(No.21976169)the National Key Research and Development Program of China(No.2022YFC3702800).
文摘To explore the multicenter characteristics of endocrine-like phthalate esters(PAEs)in household dust and propose effective control strategies for global indoor public health.An on-site observational investigation was conducted in nine Chinese cities from 2018 to 2019.A total of 246 household dust sampleswere collected and analyzed for ten PAE congeners using Gas Chromatography-Mass Spectrometry(GC-MS).Questionnaires were used to gather information on building conditions,indoor behaviors,and ventilation habits.In residential dust from the nine cities,the total concentrations of the ten PAE congeners(PAEs)ranged from 0.921 to 29097.297μg/g.Dicyclohexyl phthalate(DCHP)and di(2-ethylhexyl)phthalate(DEHP)were the dominant congeners inPAEs.Childhood exposure to PAEs through dust ingestion was four orders of magnitude higher than through inhalation,with a carcinogenic risk of 5.47×10^(−6) for DEHP exposure in household dust.HigherPAEs concentrations were associated with higher temperature,double glazing,wall paint usage,television and computer use,and indoor plant growth.This multicenter on-site investigation confirmed PAE pollution characteristics and uncovered the inacceptable risk of daily DEHP exposure in household dust under real living conditions.Effective mitigation measures based on household-related information,residential characteristics,decoration materials,and lifestyle should be taken to build a healthy household environment.
基金supported by the National Natural Science Foundation of China(grant nos.82025030,82222063,and 82388102)the National Key Research and Development Program of China(grant no.2023YFC3603400)。
文摘Objective This study aimed to evaluate the relationships of white blood cell(WBC)count,platelet(PLT)count,and PLT-to-WBC ratio(PWR)with muscle mass in Chinese older adults.Methods This cross-sectional analysis involved 4,033 Chinese older adults aged≥65 years from the Healthy Ageing and Biomarkers Cohort Study.Muscle mass and total skeletal muscle mass index(TSMI)were measured by bioelectric impedance analysis.WBC,PLT,and PWR were measured using standard methods.Multivariate linear regression was used to examine the associations of WBC count,PLT count,and PWR with TSMI.Results High WBC count,PLT count,and PWR were associated with low TSMI,with coefficients of-0.0091(95%confidence interval[CI]:-0.0142 to-0.0041),-0.0119(95%CI:-0.0170 to-0.0068),and-0.0051(95%CI:-0.0102 to-0.0001).The associations between the three inflammatory indices and TSMI were linear.Stratified analyses indicated that the relationship between inflammatory markers and TSMI was more evident in male participants and in individuals aged<80 years than in their counterparts.Conclusion Elevated WBC count,PLT count,and PWR correlated with muscle mass loss.This study highlights the importance of regular monitoring of inflammatory markers as a potential strategy for the screening and management of sarcopenia in older adults.
文摘Pacing-induced cardiomyopathy (PICM) resultsf rom the detrimental effect of frequent right ventricular pacing.^([1]) The diagnosis relies on a combination of pacing-associated ventricular dyschrony manifested with ECG wide LBBB-pattern QRS duration and clinical assessment, imaging studies. Conduction system pacing (CSP), such as His bundle pacing (HBP)and left bundle branch pacing (LBBP), may help to prevent PICM,^([2]) but the criteria for optimal patient selection remain inadequately defined.
基金financially supported by the National Natural Science Foundation of China(No.41901132)the Natural Scientific Project of Guangxi Zhuang Autonomous Region(Nos.2019GXNSFAA185015,2021GXNSFBA220025)+1 种基金the Interdisciplinary Scientific Research Foundation of Guangxi University(No.2022JCC026)the Project of Key Laboratory of Early Rapid Identification,Prevention and Control of Geological Diseases in Traffic Corridor of High Intensity Earthquake Mountainous Area of Yunnan Province(No.KLGDTC-2021-01)。
文摘Granite residual soil slope is often destroyed,which poses great threats to Rong County in southeastern Guangxi,China.Heavy rainfall and fissures are the major triggering and internal factors.The fissure that controls the slope stability and the associated failure mechanisms remain unclear.The purpose of this study was to identify the controlling fissures through field investigation,elucidate the effect of its position,and analyze the failure process and hydrological response of residual soil slope through artificial flume model tests.The results comprised five aspects.(1)Surface weathering and unloading fissures could affect slope stability.(2)The failure processes with different fissure positions exhibited inconsistent characteristics.(3)The volume moisture content(VMC)had the most direct response at the fissure tip.The corresponding infiltration rate was the highest.The response time of pore water pressure(PWP)was longer than that of VMC.Fluctuations in PWP were associated with VMC and changes in the soil microstructure due to local deformation.(4)Slope failure was accompanied by serious soil erosion.This could be attributed to the infiltration direction and the interaction between soil and water.(5)Fissured soil slopes experienced five similar failure processes:sheet erosion and partial failure of the slope foot,occurrence of preferential flow and enlargement of the sliding area,creep deformation and tension fissure emergence,block sliding and gully erosion,and flow-slip.
基金supported by National Natural Science Foundation of China(31730091,32372900,32072743)Natural Science Foundation of Sichuan Province(2023NSFSC0237)Major Science and Technology Projects in Sichuan Province(2021ZDZX0009)。
文摘Background Diarrhea remains a major health concern in both young animals and humans.Prevotella spp.,a dominant commensal genus in the healthy porcine gut,becomes increasingly abundant following weaning,suggesting a potential role during this critical transitional period.However,its involvement in post-weaning diarrhea remains poorly understood.Here,we aim to elucidate the role and underlying mechanisms of Prevotella in alleviating diarrhea in weaned piglets.Results To model unsanitary housing conditions,piglets were housed in uncleaned pens containing residual fecal matter from previous occupants and exposed to cold stress by maintaining the ambient temperature at 19℃,below the optimal 28℃.Under these conditions,piglets were orally administered either a blank medium(CON,n=10×2)or Prevotella copri at 1×10^(8)CFU(Pc,n=10×2)on d 1,3,and 5.After 28 d,cold stress induced a diarrhea incidence of 33.45%in the CON group,while P.copri supplementation significantly reduced the diarrhea rate to 19.73%.Treatment with P.copri markedly improved intestinal morphology in the small intestine,decreased serum levels of lipopolysaccharide(LPS)and intestinal fatty acid-binding protein(i-FABP),and enhanced total antioxidant capacity(T-AOC)and catalase(CAT)activity.Quantitative PCR and 16S rRNA gene sequencing revealed that P.copri significantly increased the colonic abundance of Prevotella,reshaping both the composition and functional profile of the gut microbiota.Moreover,P.copri enhanced the modularity and robustness of microbial ecological networks.Untargeted metabolomic profiling of colonic contents revealed a significant enrichment of metabolites involved in the arachidonic acid pathway following P.copri supplementation.In parallel,untargeted metabolomics of P.copri culture supernatants identified differential metabolic pathways including metabolic pathways,biosynthesis of secondary metabolites,and biosynthesis of antibiotics.In vitro assays demonstrated that P.copri-derived metabolites inhibited the growth of three common porcine intestinal pathogens.Furthermore,both P.copri metabolites and arachidonic acid enhanced intestinal barrier integrity and suppressed TNF-α-induced inflammation and apoptosis in Caco-2 cells through activation of the AHR–Nrf2 signaling pathway.Conclusions These findings highlight the role of P.copri in maintaining gut homeostasis and provide new insights into microbiota-based interventions for early-life intestinal disorders.
基金supported by the National Key Research and Development Plan of China(2021YFD2200202)the Key Research and Development Project of Jiangsu Province,China(BE2021366).
文摘Populus species,important economic species combining rapid growth with broad ecological adaptability,play a critical role in sustainable forestry and bioenergy production.In this study,we performed whole-genome resequencing of 707 individuals from a full-sib family to develop comprehensive single nucleotide polymorphism(SNP)markers and constructed a high-density genetic linkage map of 19 linkage groups.The total genetic length of the map reached 3623.65 cM with an average marker interval of 0.34 cM.By integrating multidimensional phenotypic data,89 quantitative trait loci(QTL)associated with growth,wood physical and chemical properties,disease resistance,and leaf morphology traits were identified,with logarithm of odds(LOD)scores ranging from 3.13 to 21.72 Notably,pleiotropic analysis revealed significant colocaliza and phenotypic variance explained between 1.7% and 11.6%.-tion hotspots on chromosomes LG1,LG5,LG6,LG8,and LG14,with epistatic interaction network analysis confirming genetic basis of coordinated regulation across multiple traits.Functional annotation of 207 candidate genes showed that R2R3-MYB and bHLH transcription factors and pyruvate kinase-encoding genes were significantly enriched,suggesting crucial roles in lignin biosynthesis and carbon metabolic pathways.Allelic effect analysis indicated that the frequency of favorable alleles associated with target traits ranged from 0.20 to 0.55.Incorporation of QTL-derived favorable alleles as random effects into Bayesian-based genomic selection models led to an increase in prediction accuracy ranging from 1% to 21%,with Bayesian ridge regression as the best predictive model.This study provides valuable genomic resources and genetic insights for deciphering complex trait architecture and advancing molecular breeding in poplar.
基金the National Natural Science Foundation of China （No.40572063 ） the Fostering Plan Fund for Beyond-Century Excellent Talent and the Key Project of Science and Technology Research of the Ministry of Education （ No. 03178） Fund of State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences （No. GPMR0529）.
文摘The Damoqujia gold deposit,discovered recently and located in the north of Zhaoping fault zone,is a large altered rock type deposit.In this paper,we report the preliminary research results of the fluid inclusions and discuss its metallogenic implications. The homogenization temperatures of fluid inclusions fall into four ranges:310～350℃,230～270℃,160～200℃and 110～150℃; corresponding to the four stages of hydrothermal ore-forming processes:coarse grain pyrite-milk white quartz stage(Ⅰ),smoky gray Au-bearing quartz-fine grain pyrite stage(Ⅱ),Au-bearing polymetallic sulfide-quartz stage(Ⅲ),and quartz-carbonate stage(Ⅳ). Ore-forming fluid is with low salinity and low density,ranging from 1.4 Wt_(NaCl)% to 13.6 Wt_(NaCl)% and from 0.48g/cm^3 to 1.03g/cm^3 respectively.The inclusions are dominated by H_2O and CO_2 in gaseous compositions,and Na^+ and K^+ in positive ions,SO_4^(2-)and Cl^- in negative ions of liquid compositions.Au-S complex is the major form for transportation of gold.The pressure varied from 260MPa to 340MPa during the formation of CO_2-bearing inclusions at the early mineralization;the fluids are rich in SO_4^(2-)and Na^+.The pressure is 26-49×10~5 Pa during the formation of the aqueous salt inclusions in late mineralization,the inclusions are rich in CI^-(F^-), Na^+.δ^(18)O_(qurrtz)is 10.64～12.68%o,and the correspondingδ^(18)O_(H_2)O andδD is-5.44～6.47‰and-95.52～-106.48‰respectively.Based on the studies about compositions and hydrogen and oxygen isotopes of inclusions,it is evidenced that ore-forming fluid is magmatic hydrothermal fluid in early period,but affected by meteoric water in late.
基金supported by the National Natural Science Foundation of China(Grant No.41402126)
文摘ObjectiveThis study aims to characterize the occurrences and interior structural features of botryoidal structures from the Sinian Dengying Formation in the Sichuan Basin of Southwestern China, and to shed light on their formation mechanism.
基金funded by the Major State Basic Research Development Program of China ("973" project, Grant No. 2012CB214803)National Science and Technology Major Project of China (Grant No. 2016ZX05004)
文摘During the Cambrian, gypsum-bearing evaporites formed in the Sichuan Basin, SW China. These rocks are important for oil and gas sealing, but details of their distribution and origin are not well established. This study examines the regional distribution and origin of the gypsum-bearing evaporites using a comprehensive analysis of drilling data from 34 wells, 5 measured cross-sections in the basin and surrounding area, and 96 maps of area-survey data. Results show that in the stratigraphic succession, the gypsum-bearing evaporites occur mainly in the Lower Cambrian Longwangmiao Formation, the Middle Cambrian Douposi Formation, and the Middle-Upper Cambrian Xixiangchi Group. Geographically, the rocks are found mainly in the southeastern part of the basin, and the distribution of deposits shows an overall SW-NE trend. The sedimentary environments for evaporite formation were evaporative lagoon and inter-platform basin in a platform setting. Gypsum was generated by the underwater concentration of sea water in a strongly evaporative environment. Both an evaporative restricted platform and a mixeddeposition restricted platform model appear to be applicable to the development of gypsum in the Sichuan Basin. The gypsum-bearing evaporites with the best sealing capacity are located mostly in the southeastern part of the basin. These constraints can be applied directly to regional exploration, and have implications for the regional paleogeography and paleoclimate.
基金Supported by National Nat ural Science Foundation of China(Grant Nos.51675227,51975249)Jilin Province Science and Technology Development Funds(Grant Nos.20180201007GX,20190302017GX)+2 种基金Technology Development and Research of Jilin Province(Grant No.2019C037-01)Changchun Science and Technology Planning Project(Grant No.19SS011)National Science and technology Major Project(Grant No.2014ZX04015031).
文摘Heavy-duty machine tools are composed of many subsystems with different functions,and their reliability is governed by the reliabilities of these subsystems.It is important to rank the weaknesses of subsystems and identify the weakest subsystem to optimize products and improve their reliabilities.However,traditional ranking methods based on failure mode effect and critical analysis(FMECA)does not consider the complex maintenance of products.Herein,a weakness ranking method for the subsystems of heavy-duty machine tools is proposed based on generalized FMECA information.In this method,eight reliability indexes,including maintainability and maintenance cost,are considered in the generalized FMECA information.Subsequently,the cognition best worst method is used to calculate the weight of each screened index,and the weaknesses of the subsystems are ranked using a technique for order preference by similarity to an ideal solution.Finally,based on the failure data collected from certain domestic heavy-duty horizontal lathes,the weakness ranking result of the subsystems is obtained to verify the effectiveness of the proposed method.An improved weakness ranking method that can comprehensively analyze and identify weak subsystems is proposed herein for designing and improving the reliability of complex electromechanical products.
基金Under the auspices of National Natural Science Foundation of China (No. 40375032,No. 40675043)
文摘Using the daily maximum and minimum temperature dataset from 128 stations from 1960 to 2004 in Northwest China,daily extreme high temperature(EHT)and extreme low temperature(ELT)thresholds were deter-mined by centesimal method for different stations at first,then yearly EHT and ELT events were counted up in differ-ent stations,and the characteristics of their spatio-temporal distribution were diagnosed at last.The study drew follow-ing conclusions:1)The consistent anomaly distribution characteristic was the most important mode of the EHT and ELT events in Northwest China.2)The spatial distribution of the EHT and ELT events can be divided into five sub-regions,namely,the north of Qinghai and west of Gansu,the north of Xinjiang,the south of Xinjiang,the east of Northwest China and the south of Qinghai.3)The EHT events showed remarkable increasing trend in all of five sub-regions,but only in the north of Qinghai and west of Gansu area,sudden change phenomenon occurred;the ELT events showed decreasing trend in all of five sub-regions,and sudden change phenomenon occurred in Northwest China except for south of Qinghai.4)In all of five sub-regions the EHT events showed remarkable 12-14yr period os-cillation,and the ELT event showed significant 13-15yr and 7-8yr period oscillation.5)The EHT and ELT events displayed remarkable positive and negative responses to regional warming of Northwest China respectively.
基金National Basic Research Program2007 CB 816003National Special Project2006 BAB19B01+1 种基金Grant 40376003 from Chinese National Science FoundationChina 908-Project under Grant 908-02-01-03
文摘According to the satellite remote sensing monthly mean sea surface temperature data from 1998 to 2002, it is shown that, the Sulu Sea is dominated by a cold eddy both in summer and winter. A coupled single-layer/two-layer model is employed here to study the summery and wintry characteristics and dynamic mechanism of the upper circulation in the Sulu Sea. According to the numerical experiments, it is found that, due to the local monsoon stress curl, the upper circulation in the Sulu Sea is dominated by a weak anticyclonic eddy in summer and a strong cyclonic eddy in winter. Once there is a large outflow via the Sibutu Passage flowing out of the Sulu Sea in summer, the upper circulation in the Sulu Sea may be dominated by a cyclonic eddy instead of the normal anticyclonic one. Moreover, in summer, the water exchange between the Sulu Sea and South China Sea via the Mindoro and Balabac Straits might have some effect on the separation position and strength of the northward western boundary current next to the Indo-China Peninsula in the southern South China Sea.
基金Supported by the National High Technology Research and Development Program of China (863 Program) (No. 2006AA100303)the Science and Technology Project of Guangdong Province, China (No.2007B020708001)+1 种基金the Special Funds for Operating Expenses of Basic Researches in the Central Nonprofit Scientific Research Institutes (Nos.2008TS01, 2007ZD03)the Natural Science Foundation of Guangdong Province, China (No. 04001263)
文摘We measured the target strength （TS） of three commercial fish species： whitespotted spinefoot （Siganus canaliculatus）, black porgy （Acanthopagrus schlegelii）, and creek red bream （Lutjanus argentimaculatus）, in the South China Sea. The TS of caged or tethered fish （n=76 total） was measured using a Simrad EY60 portable scientific echosounder at 120 kHz. We evaluated the relationship between TS and total length （TL, cm） for the three species. This is the first attempt to use split-beam acoustics to measure single-fish TS in the South China Sea by Chinese researchers. Our results will improve the accuracy and precision of acoustic abundance estimates of commercially important species and fi.trther the development of underwater acoustic survey techniques in fisheries in the South China Sea.
基金the National Basic Research Program of China (No. 2004CB418504)
文摘The solubility and sorption of oil by uncontaminated clay loam and silt loam soils were studied from water and cosolvent/water solutions using batch techniques. The data obtained from the dissolution and sorption experiments were used to evaluate the applicability of the cosolvent theory to oil as a complex mixture. Aqueous solubility and soil-water distribution coeffcients (Kd,w, L/kg) were estimated by extrapolating from cosolvent data, with a log-linear cosolvency model, to the volume fraction of cosolve...
基金Supported by the National Natural Science Foundation of China(41672118)Strategic Cooperation Science and Technology Project Between China University of Petroleum and Petro China(ZLZX2020-01-06)。
文摘Taking the tight oil of the Zhongnan sag in the Ordos Basin,Jimusar sag in the Junggar Basin and Qingxi sag in the Jiuquan Basin as study objects,based on field survey,dissection of tight oil reservoirs,sample test,modeling experiment and comprehensive analysis,this study reveals that the tight oil accumulates at start-up pressure,advances under differential pressure,diffuses at alternating fast and low speeds,charges in stepped large area and migrates rapidly through fractures,and enriches in dominant fractures and pores.The root cause of ladder-like charge is the multiple scales of pores.The widespread source rock with high hydrocarbon generation intensity is the material basis for tight oil enrichment;the dominant source reservoir assemblage is the basic unit for tight oil enrichment;fractures and beddings are conducive to local rapid migration of tight oil;fractures and pores work together to control the enrichment of tight oil.Two typical accumulation models of tight oil are established,namely"source reservoir in coexistence,four optimal factors controlling enrichment around central area,and large-scale continuous distribution"for a large freshwater lake clastic rock basin and"source reservoir integration,four optimal factors controlling enrichment,central area distribution,small in size but high in enrichment degree"for a small saline lake diamictite depression.
