Vine tea is documented in ancient Chinese books as having the function of promoting blood circulation.However,its effects and mechanisms remain unclear.The aim of this study was to comprehensively investigate the prot...Vine tea is documented in ancient Chinese books as having the function of promoting blood circulation.However,its effects and mechanisms remain unclear.The aim of this study was to comprehensively investigate the protective potential and mechanisms of vine tea in high-fat diet rat through a combination of in vivo and in vitro experiments.The efficacy of vine tea was evaluated using a high-fat diet rat model and an oxidized low-density lipoprotein-treated cell model,with physiological and biochemical indicators measured in rat serum and cell supernatants.Transcriptomics was utilized to investigate alterations mRNA expression following the administration of dihydromyricetin in cell model.Metabolomics and 16S rRNA sequencing was employed to examine changes in metabolites in the serum and changes in gut microbiota of high-fat diet rats after administering vine tea extract.Vine tea extract and dihydromyricetin can reduce elevated levels of lipids,including total cholesterol and triglycerides,following modeling.Transcriptomic data indicate that dihydromyricetin exerts its effects by regulating ferroptosis signaling pathways.Metabolomic analysis demonstrates that the administration of vine tea extract influences the vitamin K cycle and glutathione,thereby alleviating the progression of ferroptosis.Additionally,16S rRNA sequencing reveals that vine tea extract increases Lactobacillaceae in the gut microbiota,which subsequently affects the levels of lysophosphatidylcholine,a major phospholipid component of oxidized low-density lipoprotein in serum.Our results indicate that vine tea can regulate ferroptosis signaling pathways and increase Lactobacillaceae in the gut microbiota,thereby exhibiting cardiovascular protective effects in high-fat diet rats.展开更多
Mississippi State is renowned for its land resource areas (LRA) and production of bioenergy crops which generate both agricultural and economic benefits. Agricultural commodities play a key role in economic growth, th...Mississippi State is renowned for its land resource areas (LRA) and production of bioenergy crops which generate both agricultural and economic benefits. Agricultural commodities play a key role in economic growth, therefore the ability to produce more would enhance development. This paper offers an analysis of the production of bioenergy crops in Mississippi. Relative measures, time series graphs and descriptive statistics coupled with geographic information systems (GIS) mapping using ArcMap were employed to generate the outcome of this research. The outcome of the statistical analysis indicated that corn and soybeans were the most produced crops in Agricultural Districts 10 and 40. These districts produced more bioenergy crops than the other districts. GIS mapping results also showed that the potential area for bioenergy crops is in zone 131 of the Mississippi Land Resource Area (MLRA). This zone has an absolute advantage in the production of these crops which includes the diversity of biomass production such as corn, cotton, soybeans, wheat, rice, barley, grain sorghum, canola, camelina, algae, hardwoods, and softwood. The paper recommends a constant GIS mapping and land management systems for each agricultural district in Mississippi to enable researchers and farmers to determine the factors which contribute towards the increasing and decreasing trends in the production of the bioenergy crops.展开更多
In many respects, river basins are extremely convenient natural resources management units and hence calls for an integrated approach in case of transboundary nature. Environmental resources in Kagera basin are under ...In many respects, river basins are extremely convenient natural resources management units and hence calls for an integrated approach in case of transboundary nature. Environmental resources in Kagera basin are under great threat due to demographic factors leading to wide spread environmental degradation. Land degradation and biodiversity loss are central issues in the basin, but the extent and severity of the degradation pressures are not yet clearly illustrated and their implications largely unknown. To date, natural resource mapping in Kagera basin has been based on isolated case studies for specific purposes and not much has been done in mapping resources and classification of resources degradation by remote sensing applications considering the whole basin. In this study, basin-wide mapping approach was adopted and hot spot areas associated with natural resources use in the basin identified and trends over time established. However, this paper presents results from Kagera River sub-basin, Uganda. Mapping exercise was done by using landsat images and aerial photos of Kagera basin covering the years 1984-2002. Overall, bushland in Kagera sub-basin, Uganda increased by 78% and woodland cover showed mere 6% gain;but a 53% decrease in open woodland sub-type and 29% decrease in closed woodland. Significant shift occurred in cultivation with herbaceous crops (mainly banana) from year 1984-2002 moving from east to west of Kagera sub-basin, Uganda representing 167% increase. Area occupied by permanent swamp decreased 31%. Over the same period, land cover change detection matrix indicates main land cover changes include conversion to bushland (59.34%) followed by conversion to grassland (7.29%) and cultivated land (7.16%), with only 24.19% of the land cover remaining unchanged. It is concluded that the observed changes are, a result of human-induced factors and show unsustainable utilization of natural resources as most of the changes make the land susceptible to degradation.展开更多
Enhanced silicate weathering(ESW)is a geoengineering method aimed at accelerating carbon dioxide(CO_(2))removal(CDR)from atmosphere by increasing the weathering flux of silicate rocks and minerals.It has emerged as a ...Enhanced silicate weathering(ESW)is a geoengineering method aimed at accelerating carbon dioxide(CO_(2))removal(CDR)from atmosphere by increasing the weathering flux of silicate rocks and minerals.It has emerged as a promising strategy for CDR.Theoretical studies underscore ESW’s substantial potential for CDR and its diverse benefits for crops when applied to croplands.However,the well-known significant discrepancies in silicate weathering rates between laboratory and field conditions introduce uncertainty in CDR through ESW.By compiling data from recent literature,we calculated and compared CDR efficiency(t CO_(2)t^(-1)_(silicate)ha^(-1)y^(-1))observed in mesocosm experiments and field trials.The findings indicate that CDR efficiencies in field trials are comparable to or exceeding that observed in mesocosm experiments by 1-3 orders of magnitude,particularly evident with wollastonite application.The hierarchy of CDR efficiency among silicates suitable for ESW is ranked as follows:olivine≥wollastonite>basalt>albite≥anorthite.We suggest the potential role of biota,especially fungi,in contributing to higher CDR efficiencies observed in field trials compared to mesocosm experiments.We further emphasize introducing fungi known for their effectiveness in silicate weathering could potentially enhance CDR efficiency through ESW in croplands.But before implementing fungal-facilitated ESW,three key questions need addressing:(i)How does the community of introduced fungi evolve over time?(ii)What is the long-term trajectory of CDR efficiency following fungal introduction?and(iii)Could fungal introduction lead to organic matter oxidation,resulting in elevated CO_(2)emissions?These investigations are crucial for optimizing the efficiency and sustainability of fungal-facilitated ESW strategy.展开更多
Enhanced Cd uptake and Zn depletion in rice grains and high potential for food Cd exposure by the high-yielding hybrid cultivars of China had been addressed.A field experiment was conducted in 2006 to determine the di...Enhanced Cd uptake and Zn depletion in rice grains and high potential for food Cd exposure by the high-yielding hybrid cultivars of China had been addressed.A field experiment was conducted in 2006 to determine the difference in grain Cd and Zn between cultivars.Total 110 cultivars including super rice and common hybrid rice cultivars were grown on a single paddy soil(Entic Haplaquept)with a neutral reaction and low total Cd content.Grain Cd and Zn concentrations were determined with graphite atomic adsorption spectrophotometer(GFAAS)and flame atomic adsorption spectrophotometer(AAS)respectively.Wide variation of Cd content in grain was found in a range of 0.004-0.057 mg/kg,while the Zn content in a range of 10.25-30.06 mg/kg among the cultivars.Higher Cd but lower Zn concentration in grains of super rice cultivars was observed compared to the common hybrid ones.A highly significant positive linear correlation of grain Cd/Zn with grain Cd was found for super rice and common hybrid cultivars,meanwhile much higher slope for these hybrid cultivars than the reported non-hybrid cultivars was also observed.Using the limit value of the Chinese chemical guidelines for foods(MOHC and SSC,2005),calculated potential risk of food Cd exposure with"Zn hungry"through diet intake was prominent with all the studied 110 hybrid rice cultivars,possessing high potential health problems for rice production in South China using the super rice cultivars.Breeding of genotypes of rice cultivars with low grain Cd and low Cd/Zn ratio is needed for rice production in acidic red soils where Cd bioavailability is prevalently high.展开更多
Developing realistic soil carbon （C） sequestration strategies for China＇s sustainable agriculture relies on accurate estimates of the amount, retention and turnover rates of C stored in paddy soils. Available C est...Developing realistic soil carbon （C） sequestration strategies for China＇s sustainable agriculture relies on accurate estimates of the amount, retention and turnover rates of C stored in paddy soils. Available C estimates to date are predominantly for the tilled and flood-irrigated surface topsoil （ca. 30 cm）. Such estimates cannot be used to extrapolate to soil depths of 100 cm since soil organic carbon （SOC） generally shows a sharp decrease with depth. In this research, composite soil samples were collected at several depths to 100 cm from three representative paddy soils in the Taihu Lake region, China. Soil organic carbon distribution in the profiles and in aggregate-size fractions was determined. Results showed that while SOC decreased exponentially with depth to 100 cm, a substantial proportion of the total SOC （30%-40%） is stored below the 30 cm depth. In the carbon-enriched paddy topsoils, SOC was found to accumulate preferentially in the 2-0.25 and 0.25-0.02 mm aggregate size fractions. δ^13C analysis of the coarse micro-aggregate fraction showed that the high degree of C stratification in the paddy topsoil was in agreement with the occurrence of lighter δ^1313C in the upper 30 cm depth. These results suggest that SOC stratification within profiles varies with different pedogenetical types of paddy soils with regards to clay and iron oxyhydrates distributions. Sand-sized fractions of aggregates in paddy soil systems may play a very important role in carbon sequestration and turnover, dissimilar to other studied agricultural systems.展开更多
Effects of free iron oxyhydrates(Fed)and soil organic matter(SOM)on copper(Cu^2+)sorption-desorption behavior by size fractions of aggregates from two typical paddy soils(Ferric-Accumulic Stagnic Anthrosol(Soil H)and ...Effects of free iron oxyhydrates(Fed)and soil organic matter(SOM)on copper(Cu^2+)sorption-desorption behavior by size fractions of aggregates from two typical paddy soils(Ferric-Accumulic Stagnic Anthrosol(Soil H)and Gleyic Stagnic Anthrosol(Soil W))were investigated with and without treatments of dithionite-citrate-bicarbonate and of H2O2.The size fractions of aggregates were obtained from the undisturbed bulk topsoil using a low energy ultrasonic dispersion procedure.Experiments of equilibrium sorption and subsequent desorption were conducted at soil water ratio of 1:20,25℃.For Soil H,Cu^2+sorption capacity of the DCB-treated size fractions was decreased by 5.9%for fine sand fraction,by 40.4%for coarse sand fraction,in comparison to 2.9%for the bnlk sample.However,Cu^2+sorption capacities of the H2O2-treated fractions were decreased by over 80%for the coarse sand fraction and by 15%for the clay-sized fraction in comparison to 88%for bulk soil.For Soil W,Cu^2+sorption capacity of the DCB-treated size fraction was decreased by 30%for the coarse sand fraction and by over 75%for silt sand fraction in comparison to 44.5%for the bulk sample.Cu^2+sorption capacities of the H2O2-treated fractions were decreased by only 2.0%for the coarse sand fraction and by 15%for the fine sand fraction in comparison to by 3.4%for bulk soil.However,Cu^2+desorption rates were increased much in H2O2-treated samples by over 80%except the clay-sized fraction(only 9.5%)for Soil H.While removal of SOM with H2O2 tendend to increase the desorption rate,DCB-and H2O2-treatments caused decrease in Cu^2+retention capacity of size fractions,Particularly,there hardly remained Cu^2+retention capacity by size fractions from Soil H after H2O2 treatment except for clay-sized fraction.These findings supported again the dominance of the coarse sand fraction in sorption of metals and the preference of absorbed metals bound to SOM in differently stabilized status among the size fractions.Thus,enrichment and turnover of SOM in paddy soils may have great effects on metal retention and chemical mobility in paddy soils.展开更多
Oxidation pressure leaching was proposed to selectively dissolve Li from spent LiFePO_(4)batteries in a stoichiometric sulfuric acid solution.Using O_(2)as an oxidant and stoichiometric sulfuric acid as leaching agent...Oxidation pressure leaching was proposed to selectively dissolve Li from spent LiFePO_(4)batteries in a stoichiometric sulfuric acid solution.Using O_(2)as an oxidant and stoichiometric sulfuric acid as leaching agent,above 97%of Li was leached into the solution,whereas more than 99%of Fe remained in the leaching residue,enabling a relatively low cost for one-step separation of Li and Fe.And then,by adjusting the pH of leachate,above 95%of Li was recovered in the form of the Li_(3)PO_(4)product through iron removal and chemical precipitation of phosphate.展开更多
AIM:To explore differences in biochemical indices between neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) and that with other etiologies. METHODS:Patients under 6 mo of age who were referred for ...AIM:To explore differences in biochemical indices between neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) and that with other etiologies. METHODS:Patients under 6 mo of age who were referred for investigation of conjugated hyperbiliru-binaemia from June 2003 to December 2010 were eligible for this study. After excluding diseases affecting the extrahepatic biliary system, all patients were screened for the two most common SLC25A13 mutations; the coding exons of the entire SLC25A13 gene was sequenced and Western blotting of citrin protein performed in selected cases. Patients in whom homo-zygous or compound heterozygous SLC25A13 mutation and/or absence of normal citrin protein was detected were defined as having NICCD. Cases in which no specific etiological factor could be ascertained after a com-prehensive conjugated hyperbilirubinaemia work-up were defined as idiopathic neonatal cholestasis (INC). Thirty-two NICCD patients, 250 INC patients, and 39 infants with cholangiography-confirmed biliary atresia (BA) were enrolled. Laboratory values at their first visit were abstracted from medical files and compared. RESULTS:Compared with BA and INC patients, the NICCD patients had significantly higher levels of total bile acid (TBA) [all measures are expressed as median (inter-quartile range):178.0 (111.2-236.4) μmol/L in NICCD vs 112.0 (84.9-153.9) μmol/L in BA and 103.0 (70.9-135.3) μmol/L in INC, P = 0.0001]. The NICCD patients had significantly lower direct bilirubin [D-Bil 59.6 (43.1-90.9) μmol/L in NICCD vs 134.0 (115.9-151.2) μmol/L in BA and 87.3 (63.0-123.6) μmol/L in INC, P = 0.0001]; alanine aminotransferase [ALT 34.0 (23.0-55.0) U/L in NICCD vs 108.0 (62.0-199.0) U/L in BA and 84.5 (46.0-166.0) U/L in INC, P = 0.0001]; aspartate aminotransferase [AST 74.0 (53.5-150.0) U/L in NICCD vs 153.0 (115.0-239.0) U/L in BA and 130.5 (81.0-223.0) U/L in INC, P = 0.0006]; albumin [34.9 (30.7-38.2) g/L in NICCD vs 38.4 (36.3-42.2) g/L in BA and 39.9 (37.0-42.3) g/L in INC, P = 0.0001]; glucose [3.2 (2.0-4.4) mmol/L in NICCD vs 4.1 (3.4-5.1) mmol/L in BA and 4.0 (3.4-4.6) mmol/L in INC, P = 0.0014] and total cholesterol [TCH 3.33 (2.97-4.00) mmol/L in N ICCD vs 4.57 (3.81-5.26) mmol/L in BA and 4.00 (3.24-4.74) mmol/L in INC, P = 0.0155] levels. The D-Bil to total bilirubin (T-Bil) ratio was significantly lower in NICCD patients [all measures are expressed as median (inter-quartile range):0.54 (0.40-0.74)] than that in BA patients [0.77 (0.72-0.81), P = 0.001] and that in INC patients [0.74 (0.59-0.80), P = 0.0045]. A much higher AST/ALT ratio was found in NICCD patients [2.46 (1.95-3.63)] compared to BA patients [1.38 (0.94-1.97), P = 0.0001] and INC patients [1.48 (1.10-2.26), P = 0.0001]. NICCD patients had significantly higher TBA/D-Bil ratio [3.36 (1.98-4.43) vs 0.85 (0.72-1.09) in BA patients and 1.04 (0.92-1.14) in INC patients, P = 0.0001], and TBA/TCH ratio [60.7 (32.4-70.9) vs 24.7 (19.8-30.2) in BA patients and 24.2 (21.4-26.9) in INC patients, P = 0.0001] compared to the BA and INC groups. CONCLUSION:NICCD has significantly different bio- chemical indices from BA or INC. TBA excretion in NICCD appeared to be more severely disturbed than that of bilirubin and cholesterol.展开更多
Ammonia oxidizing （AOB） and denitrifying bacteria （DNB） play an important role in soil nitrogen transformation in natural and agricultural ecosystems. Effects of long-term fertilization on abundance and community ...Ammonia oxidizing （AOB） and denitrifying bacteria （DNB） play an important role in soil nitrogen transformation in natural and agricultural ecosystems. Effects of long-term fertilization on abundance and community composition of AOB and DNB were studied with targeting ammonia monooxygenase （amoA） and nitrite reductase （nirK） genes using polymerase chain reaction- denaturing gradient gel electrophoresis （PCR-DGGE） and real-time PCR, respectively. A field trial with different fertilization treatments in a rice paddy from Tai Lake region, centre East China was used in this study, including no fertilizer application （NF）, balanced chemical fertilizers （CF）, combined organic/inorganic fertilizer of balanced chemical fertilizers plus pig manure （CFM）, and plus rice straw return （CFS）. The abundances and riehnesses of amoA and nirK were increased in CF, CFM and CFS compared to NF. Principle component analysis of DGGE profiles showed significant difference in nirK and amoA genes composition between organic amended （CFS and CFM） and the non-organic amended （CF and NF） plots. Number of amoA copies was significantly positively correlated with normalized soil nutrient richness （NSNR） of soil organic carbon （SOC） and total nitrogen （T-N）, and that of nirK copies was with NSNR of SOC, T-N plus total phosphorus. Moreover, nitrification potential showed a positive correlation with SOC content, while a significantly lower denitrification potential was found under CFM compared to under CFS. Therefore, SOC accumulation accompanied with soil nutrient richness under long-term balanced and organic/inorganic combined fertilization promoted abundance and diversity of AOB and DNB in the rice paddy.展开更多
Muscovite mineral was roasted in different conditions.Rubidium leaching rate was a standard to examine the impact of various factors on calcination effect,including the agent types,roasting time,mass ratio,and roastin...Muscovite mineral was roasted in different conditions.Rubidium leaching rate was a standard to examine the impact of various factors on calcination effect,including the agent types,roasting time,mass ratio,and roasting temperature.The results indicate that the best agent is the combination of sodium chloride and calcium chloride,and its mass ratio of muscovite/NaCl/CaCl2is1.00:0.25:0.25.Calcined at 850℃ for 30 min,the rubidium leaching rate is up to 90.12%.The reaction of muscovite ore with the chlorinating agent CaCl2was studied by TG/DSC,and the surface morphology before and after leaching was characterized by SEM.Rubidium chloride products can be obtained using t-BAMBP extraction,hydrochloric acid re-extraction,and purification.展开更多
By means of ISM (Interpretative Structural Modeling) and SD (System Dynamics) methods, this paper made a system dynamics model of urbanization and eco-environment coupling in Jiangsu Province according to the implicat...By means of ISM (Interpretative Structural Modeling) and SD (System Dynamics) methods, this paper made a system dynamics model of urbanization and eco-environment coupling in Jiangsu Province according to the implication and PSR (Pressure State Response) framework of urbanization and eco-environment coupling. Moreover, five typical scenarios during 2000-2015 have been simulated and analyzed based on the time serial statistical data during 1990-2003 in Jiangsu, which indicates: firstly, there are significant differences between the results and the scenarios, and the five coupling models all have comparative advantages and drawbacks; secondly, in terms of the characteristics and regional development disparities of Jiangsu and the general rule of world urbanization process, this paper reveals that only when either population urbanization model or social urbanization model to be correspondingly adopted, the sustainable development among population, economy, urbanization and eco-environment can be realized.展开更多
The biogenic sedimentary structures(i.e.,the morphology and trace makers of burrows,tracks,trails and traces made by extant organisms)and their composition and distribution characters in different micro environments a...The biogenic sedimentary structures(i.e.,the morphology and trace makers of burrows,tracks,trails and traces made by extant organisms)and their composition and distribution characters in different micro environments and sub environments of the Yellow River delta in China are described.Three ichnocoenosis can be recognized:(1)Steinichnus-like ichnocoenosis,includes F,Y-shaped traces,birds'footprints on bedding plane,and Y,U-shaped burrows in intrastratal bedding,produced by Coleoptera(Heteroceridae),Orthoptera(Gryllotalpidae)and birds.It is majorly found at the delta plain point bar deposits,denoting the fresh water-related terrestrial environments.(2)Steinichnus-Psilonichnus-like ichnocoenosis,consitsis of Steinichnus-like traces on the bedding plane and Psilonichnus-like burrow which a vertical,irregularly J-,Y-,or U-shaped burrows,some of them with bulbous basal cells burrows in the intrastratal bedding,created by Coleoptera(Heteroceridae),Orthoptera(Gryllotalpidae)and crabs.It is observed in the delta plain abandoned distributary channels,and the delta front tidal creek and subaquous distributary channels,indicating the brackish water environment.(3)Palaeophycus-like ichnocoenosis,includes the round entrance burrows or with craters-shaped loop-protrusionsand and the parallel forked trails on the bedding plane,and the U,J or vertical shaped feeding burrows are in the intrastratal bedding,majorly produced by the clam(bivalve molluscs),gastropods and Nereis.It is present in the subaqueous interdistributary bay,reflecting the intertidal related environment.展开更多
The yellow meal worm （Tenebrio molitor L.） is an important resource insect typically used as animal feed additive. It is also widely used for biological research. The first complete mitochondrial genome of T. rnolit...The yellow meal worm （Tenebrio molitor L.） is an important resource insect typically used as animal feed additive. It is also widely used for biological research. The first complete mitochondrial genome of T. rnolitor was determined for the first time by long PCR and conserved primer walking approaches. The results showed that the entire mitogenome of T. molitor was 15 785 bp long, with 72.35% A＋T content [deposited in GenBank with accession number KF418153]. The gene order and orientation were the same as the most common type suggested as ancestral for insects. Two protein-coding genes used atypical start codons （CTA in ND2 and AAT in COX1）, and the remaining 11 protein-coding genes started with a typical insect initiation codon ATN. All tRNAs showed standard clover-leaf structure, except for tRNASer （AGN）, which lacked a dihydrouridine （DHU） arm. The newly added T. molitor mitogenome could provide information for future studies on yellow meal worm.展开更多
Foreign trade drives China's growth,but as the trade scale continues to expand,the carbon emissions also increase quickly.Based on the industry panel data from 1996 to 2010,this paper calculates carbon emissions o...Foreign trade drives China's growth,but as the trade scale continues to expand,the carbon emissions also increase quickly.Based on the industry panel data from 1996 to 2010,this paper calculates carbon emissions of 27manufacturing industries.According to the intensity of carbon emissions,this paper divides the manufacturing sectors into low carbon and high carbon manufacturing industry and then analyzes the carbon emission trends.Next,the paper uses the feasible generalized least square regression to verify the existence of environmental Kuznets curve(EKC)of the manufacturing industry's carbon.In order to investigate the carbon leakage problem,the regression also includes the interaction term between trade and industrial value added.Our findings are as follows:the carbon emissions of the whole manufacturing industry and low carbon manufacturing industry accord with the EKC curve,but have a linear relationship with the high carbon manufacturing industry;trade reduces the carbon emissions of the whole manufacturing industry and low carbon manufacturing industry,but it increases those of the high carbon manufacturing industry;for the whole manufacturing industry and low carbon manufacturing industry,there is no carbon leakage,but it exists in the high carbon manufacturing industry.On the whole,pollution haven hypothesis does not hold up in China,and China does not need to limit industry foreign trade to reduce the emission of CO_2.But the manufacturing industry will still be the main engine of the economic growth,and therefore our country should make an effective low-carbon policy,introduce advanced technology,increase R&D investment into lowcarbon technologies,and upgrade and transform the original equipment to change the backward mode of production.展开更多
The Taihu Lake region in East China has become prone to soil acidification, which changes heavy metals such as copper(Cu) in soil into water-soluble species and increases the mobility and contamination risks of heavy ...The Taihu Lake region in East China has become prone to soil acidification, which changes heavy metals such as copper(Cu) in soil into water-soluble species and increases the mobility and contamination risks of heavy metals in the biological environment. In this study, the kinetics of Cu2+sorption by the bulk soil and the aggregate size fractions of an acidic paddy soil collected from the Taihu Lake region, the effects of temperature on Cu2+sorption, and the p H changes of the solution were investigated by static sorption and magnetic stirring. The aggregate size fractions were prepared by low-energy ultrasonic dispersing and freeze-drying. The total sorption amounts of the bulk soil and the aggregate size fractions for Cu2+followed a descending order of clay > coarse sand > bulk soil > silt> sand, corresponding to those of organic matter content, free iron oxide content, free aluminum oxide content, and cation exchange capacity. The kinetic sorption curves of Cu2+by the bulk soil and the aggregates, which were divided into two stages(rapid and slow sequentially), were well fitted by the first-order equation, the diffusion equation, and the Elovich equation, showing significant correlations(P < 0.05). Specific and non-specific sorption dominated in the fast and slow stages, respectively, and the former was predominant throughout the sorption process. The specific sorption accelerated and the non-specific sorption decelerated with rising temperature. The p H of the solution decreased significantly during the specific sorption and remained unchanged or increased slightly during the non-specific sorption. When the specific sorption terminated, the p H of the solution was minimized nearly simultaneously.The sorption progress of Cu2+by the bulk soil significantly preceded that by the aggregates. Therefore, heavy metal contamination may be another factor reducing soil p H and metal sorption forms should be taken into consideration in studies of mitigating soil heavy metal pollution or determining environmental capacity of heavy metal in soil.展开更多
The chemical composition, the content and the leachability of heavy metals in municipal solid waste incineration （ MSWI） fly ash were tested and analyzed. It is shown that the leachability of Pb and Cr exceeds the l...The chemical composition, the content and the leachability of heavy metals in municipal solid waste incineration （ MSWI） fly ash were tested and analyzed. It is shown that the leachability of Pb and Cr exceeds the leaching toxicity standard, and so the MSWI fly ash is considered as hazardous waste and must be solidifled. The effect of solidifying the MSWI fly ash by cement was studied, and it is indicated that the heavy metals can be well immobilized if the mass fraction of the fly ash is appropriate. The heavy metals were immobilized within cement hydration products through either physical fixation, substhtaion, deposition or adsorption mechanisms.展开更多
With the help of scanning electronic microscopy and X-ray diffraction, the relationships of microstructure characteristics, phase assemblage, and fracture micrograph of Al2O3/ZrO2 laminated ceramics were studied. Comp...With the help of scanning electronic microscopy and X-ray diffraction, the relationships of microstructure characteristics, phase assemblage, and fracture micrograph of Al2O3/ZrO2 laminated ceramics were studied. Compared with monolithic Al2O3/ZrO2 ceramics, the existence of surface compressive stresses greatly restrained the growth of ZrO2 and Al2O3 grains at high sinter temperature, fined the grain size, and increased the content of metastable t-ZrO2, which made the fracture transformation energy quantity 70% higher than that of the monolithic ceramics. The trans-granular and inter-granular fracture features were observed in the surface and center layers, which further verified that transformation toughening is the main mechanism, whereas, micro-crack toughening is helpful for enhancing fracture toughness.展开更多
Due to its low volatile characteristics of lean coal,it is difficult to catch fire and burn out.Therefore,high temperature is needed to maintain combustion efficiency,while,this leads to high nitrogen oxide emission.F...Due to its low volatile characteristics of lean coal,it is difficult to catch fire and burn out.Therefore,high temperature is needed to maintain combustion efficiency,while,this leads to high nitrogen oxide emission.For power plant boilers burning lean coal,stable combustion with lower nitrogen oxide emission is a challenging task.This study applied the 3D numerical simulation on the analysis of a novel de-coupling burner for low-volatile coal and its structure and operation parameters optimization.Results indicate that although it was more difficult for lean coal decoupling burner to ignite lean coal than high volatile coal,the burner formed a stepwise ignition trend,which promoted the rapid ignition of lean coal.Comparison of three central partition plate structure shows that in terms of characteristics of the flow field distribution,rich and lean separation and combustion,the structure with an inclination of 0°showed good performance,with its rich-lean air ratio being 0.85 and concentration ratio being 22.94,and there was an apparent decoupling combustion characteristic.Finally,the structure of the selected burner was optimized for its operational conditions.The optimal operating parameters was determined as the primary air velocity of 24.9 m·s^-1 and the mass flow rate of pulverized coal of 2.5 kg·s^-1,in which the pyrolysis products were utilized as reductive agent more fully.Eventually,the nitrogen oxide was efficiently reduced to nitrogen,which emission concentration was 61.88%lower than that in the design condition.展开更多
基金supported by Project of Zhangjiajie City’s Industry-Academia-Research Collaborative Innovation‘Open Project Leader’,Zhangjiajie City’s Project of Taking on Challenging Tasks by Responding to Calls for Solutions(JB20230530)Basic Research Funds Project for Central Universities of China(2023XCZX001,2020kfyXJJS120)Academician and Expert Workstations in Yunnan Province(202205AF150090).
文摘Vine tea is documented in ancient Chinese books as having the function of promoting blood circulation.However,its effects and mechanisms remain unclear.The aim of this study was to comprehensively investigate the protective potential and mechanisms of vine tea in high-fat diet rat through a combination of in vivo and in vitro experiments.The efficacy of vine tea was evaluated using a high-fat diet rat model and an oxidized low-density lipoprotein-treated cell model,with physiological and biochemical indicators measured in rat serum and cell supernatants.Transcriptomics was utilized to investigate alterations mRNA expression following the administration of dihydromyricetin in cell model.Metabolomics and 16S rRNA sequencing was employed to examine changes in metabolites in the serum and changes in gut microbiota of high-fat diet rats after administering vine tea extract.Vine tea extract and dihydromyricetin can reduce elevated levels of lipids,including total cholesterol and triglycerides,following modeling.Transcriptomic data indicate that dihydromyricetin exerts its effects by regulating ferroptosis signaling pathways.Metabolomic analysis demonstrates that the administration of vine tea extract influences the vitamin K cycle and glutathione,thereby alleviating the progression of ferroptosis.Additionally,16S rRNA sequencing reveals that vine tea extract increases Lactobacillaceae in the gut microbiota,which subsequently affects the levels of lysophosphatidylcholine,a major phospholipid component of oxidized low-density lipoprotein in serum.Our results indicate that vine tea can regulate ferroptosis signaling pathways and increase Lactobacillaceae in the gut microbiota,thereby exhibiting cardiovascular protective effects in high-fat diet rats.
文摘Mississippi State is renowned for its land resource areas (LRA) and production of bioenergy crops which generate both agricultural and economic benefits. Agricultural commodities play a key role in economic growth, therefore the ability to produce more would enhance development. This paper offers an analysis of the production of bioenergy crops in Mississippi. Relative measures, time series graphs and descriptive statistics coupled with geographic information systems (GIS) mapping using ArcMap were employed to generate the outcome of this research. The outcome of the statistical analysis indicated that corn and soybeans were the most produced crops in Agricultural Districts 10 and 40. These districts produced more bioenergy crops than the other districts. GIS mapping results also showed that the potential area for bioenergy crops is in zone 131 of the Mississippi Land Resource Area (MLRA). This zone has an absolute advantage in the production of these crops which includes the diversity of biomass production such as corn, cotton, soybeans, wheat, rice, barley, grain sorghum, canola, camelina, algae, hardwoods, and softwood. The paper recommends a constant GIS mapping and land management systems for each agricultural district in Mississippi to enable researchers and farmers to determine the factors which contribute towards the increasing and decreasing trends in the production of the bioenergy crops.
文摘In many respects, river basins are extremely convenient natural resources management units and hence calls for an integrated approach in case of transboundary nature. Environmental resources in Kagera basin are under great threat due to demographic factors leading to wide spread environmental degradation. Land degradation and biodiversity loss are central issues in the basin, but the extent and severity of the degradation pressures are not yet clearly illustrated and their implications largely unknown. To date, natural resource mapping in Kagera basin has been based on isolated case studies for specific purposes and not much has been done in mapping resources and classification of resources degradation by remote sensing applications considering the whole basin. In this study, basin-wide mapping approach was adopted and hot spot areas associated with natural resources use in the basin identified and trends over time established. However, this paper presents results from Kagera River sub-basin, Uganda. Mapping exercise was done by using landsat images and aerial photos of Kagera basin covering the years 1984-2002. Overall, bushland in Kagera sub-basin, Uganda increased by 78% and woodland cover showed mere 6% gain;but a 53% decrease in open woodland sub-type and 29% decrease in closed woodland. Significant shift occurred in cultivation with herbaceous crops (mainly banana) from year 1984-2002 moving from east to west of Kagera sub-basin, Uganda representing 167% increase. Area occupied by permanent swamp decreased 31%. Over the same period, land cover change detection matrix indicates main land cover changes include conversion to bushland (59.34%) followed by conversion to grassland (7.29%) and cultivated land (7.16%), with only 24.19% of the land cover remaining unchanged. It is concluded that the observed changes are, a result of human-induced factors and show unsustainable utilization of natural resources as most of the changes make the land susceptible to degradation.
基金funded by the National Natural Science Foundation of China(Nos.42173059 and 41991322)。
文摘Enhanced silicate weathering(ESW)is a geoengineering method aimed at accelerating carbon dioxide(CO_(2))removal(CDR)from atmosphere by increasing the weathering flux of silicate rocks and minerals.It has emerged as a promising strategy for CDR.Theoretical studies underscore ESW’s substantial potential for CDR and its diverse benefits for crops when applied to croplands.However,the well-known significant discrepancies in silicate weathering rates between laboratory and field conditions introduce uncertainty in CDR through ESW.By compiling data from recent literature,we calculated and compared CDR efficiency(t CO_(2)t^(-1)_(silicate)ha^(-1)y^(-1))observed in mesocosm experiments and field trials.The findings indicate that CDR efficiencies in field trials are comparable to or exceeding that observed in mesocosm experiments by 1-3 orders of magnitude,particularly evident with wollastonite application.The hierarchy of CDR efficiency among silicates suitable for ESW is ranked as follows:olivine≥wollastonite>basalt>albite≥anorthite.We suggest the potential role of biota,especially fungi,in contributing to higher CDR efficiencies observed in field trials compared to mesocosm experiments.We further emphasize introducing fungi known for their effectiveness in silicate weathering could potentially enhance CDR efficiency through ESW in croplands.But before implementing fungal-facilitated ESW,three key questions need addressing:(i)How does the community of introduced fungi evolve over time?(ii)What is the long-term trajectory of CDR efficiency following fungal introduction?and(iii)Could fungal introduction lead to organic matter oxidation,resulting in elevated CO_(2)emissions?These investigations are crucial for optimizing the efficiency and sustainability of fungal-facilitated ESW strategy.
基金supported by the Ministry of Science and Technology of China(No.2006BAD17B06)the Ministry of Education of China(No.B200613).
文摘Enhanced Cd uptake and Zn depletion in rice grains and high potential for food Cd exposure by the high-yielding hybrid cultivars of China had been addressed.A field experiment was conducted in 2006 to determine the difference in grain Cd and Zn between cultivars.Total 110 cultivars including super rice and common hybrid rice cultivars were grown on a single paddy soil(Entic Haplaquept)with a neutral reaction and low total Cd content.Grain Cd and Zn concentrations were determined with graphite atomic adsorption spectrophotometer(GFAAS)and flame atomic adsorption spectrophotometer(AAS)respectively.Wide variation of Cd content in grain was found in a range of 0.004-0.057 mg/kg,while the Zn content in a range of 10.25-30.06 mg/kg among the cultivars.Higher Cd but lower Zn concentration in grains of super rice cultivars was observed compared to the common hybrid ones.A highly significant positive linear correlation of grain Cd/Zn with grain Cd was found for super rice and common hybrid cultivars,meanwhile much higher slope for these hybrid cultivars than the reported non-hybrid cultivars was also observed.Using the limit value of the Chinese chemical guidelines for foods(MOHC and SSC,2005),calculated potential risk of food Cd exposure with"Zn hungry"through diet intake was prominent with all the studied 110 hybrid rice cultivars,possessing high potential health problems for rice production in South China using the super rice cultivars.Breeding of genotypes of rice cultivars with low grain Cd and low Cd/Zn ratio is needed for rice production in acidic red soils where Cd bioavailability is prevalently high.
文摘Developing realistic soil carbon （C） sequestration strategies for China＇s sustainable agriculture relies on accurate estimates of the amount, retention and turnover rates of C stored in paddy soils. Available C estimates to date are predominantly for the tilled and flood-irrigated surface topsoil （ca. 30 cm）. Such estimates cannot be used to extrapolate to soil depths of 100 cm since soil organic carbon （SOC） generally shows a sharp decrease with depth. In this research, composite soil samples were collected at several depths to 100 cm from three representative paddy soils in the Taihu Lake region, China. Soil organic carbon distribution in the profiles and in aggregate-size fractions was determined. Results showed that while SOC decreased exponentially with depth to 100 cm, a substantial proportion of the total SOC （30%-40%） is stored below the 30 cm depth. In the carbon-enriched paddy topsoils, SOC was found to accumulate preferentially in the 2-0.25 and 0.25-0.02 mm aggregate size fractions. δ^13C analysis of the coarse micro-aggregate fraction showed that the high degree of C stratification in the paddy topsoil was in agreement with the occurrence of lighter δ^1313C in the upper 30 cm depth. These results suggest that SOC stratification within profiles varies with different pedogenetical types of paddy soils with regards to clay and iron oxyhydrates distributions. Sand-sized fractions of aggregates in paddy soil systems may play a very important role in carbon sequestration and turnover, dissimilar to other studied agricultural systems.
基金supported by the National Natural Science Foundation of China(No.40231016).
文摘Effects of free iron oxyhydrates(Fed)and soil organic matter(SOM)on copper(Cu^2+)sorption-desorption behavior by size fractions of aggregates from two typical paddy soils(Ferric-Accumulic Stagnic Anthrosol(Soil H)and Gleyic Stagnic Anthrosol(Soil W))were investigated with and without treatments of dithionite-citrate-bicarbonate and of H2O2.The size fractions of aggregates were obtained from the undisturbed bulk topsoil using a low energy ultrasonic dispersion procedure.Experiments of equilibrium sorption and subsequent desorption were conducted at soil water ratio of 1:20,25℃.For Soil H,Cu^2+sorption capacity of the DCB-treated size fractions was decreased by 5.9%for fine sand fraction,by 40.4%for coarse sand fraction,in comparison to 2.9%for the bnlk sample.However,Cu^2+sorption capacities of the H2O2-treated fractions were decreased by over 80%for the coarse sand fraction and by 15%for the clay-sized fraction in comparison to 88%for bulk soil.For Soil W,Cu^2+sorption capacity of the DCB-treated size fraction was decreased by 30%for the coarse sand fraction and by over 75%for silt sand fraction in comparison to 44.5%for the bulk sample.Cu^2+sorption capacities of the H2O2-treated fractions were decreased by only 2.0%for the coarse sand fraction and by 15%for the fine sand fraction in comparison to by 3.4%for bulk soil.However,Cu^2+desorption rates were increased much in H2O2-treated samples by over 80%except the clay-sized fraction(only 9.5%)for Soil H.While removal of SOM with H2O2 tendend to increase the desorption rate,DCB-and H2O2-treatments caused decrease in Cu^2+retention capacity of size fractions,Particularly,there hardly remained Cu^2+retention capacity by size fractions from Soil H after H2O2 treatment except for clay-sized fraction.These findings supported again the dominance of the coarse sand fraction in sorption of metals and the preference of absorbed metals bound to SOM in differently stabilized status among the size fractions.Thus,enrichment and turnover of SOM in paddy soils may have great effects on metal retention and chemical mobility in paddy soils.
基金the financial supports from the National Natural Science Foundation of China(Nos.51804083,52104395,21906031)the Natural Science Foundation of Guangdong Province,China(No.2019A1515011628)+1 种基金the Science and Technology Planning Project of Guangdong Province,China(No.2017B090907026)the Special Program of Guangdong Academy of Sciences,China(Nos.2019GDASYL-0103069,2020GDASYL-0104027,2020GDASYL-0302004,2020GDASYL-0302009,2021GDASYL-0302004)。
文摘Oxidation pressure leaching was proposed to selectively dissolve Li from spent LiFePO_(4)batteries in a stoichiometric sulfuric acid solution.Using O_(2)as an oxidant and stoichiometric sulfuric acid as leaching agent,above 97%of Li was leached into the solution,whereas more than 99%of Fe remained in the leaching residue,enabling a relatively low cost for one-step separation of Li and Fe.And then,by adjusting the pH of leachate,above 95%of Li was recovered in the form of the Li_(3)PO_(4)product through iron removal and chemical precipitation of phosphate.
基金Supported by National Science Foundation of China, No. 30973230 and No. 81070281
文摘AIM:To explore differences in biochemical indices between neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) and that with other etiologies. METHODS:Patients under 6 mo of age who were referred for investigation of conjugated hyperbiliru-binaemia from June 2003 to December 2010 were eligible for this study. After excluding diseases affecting the extrahepatic biliary system, all patients were screened for the two most common SLC25A13 mutations; the coding exons of the entire SLC25A13 gene was sequenced and Western blotting of citrin protein performed in selected cases. Patients in whom homo-zygous or compound heterozygous SLC25A13 mutation and/or absence of normal citrin protein was detected were defined as having NICCD. Cases in which no specific etiological factor could be ascertained after a com-prehensive conjugated hyperbilirubinaemia work-up were defined as idiopathic neonatal cholestasis (INC). Thirty-two NICCD patients, 250 INC patients, and 39 infants with cholangiography-confirmed biliary atresia (BA) were enrolled. Laboratory values at their first visit were abstracted from medical files and compared. RESULTS:Compared with BA and INC patients, the NICCD patients had significantly higher levels of total bile acid (TBA) [all measures are expressed as median (inter-quartile range):178.0 (111.2-236.4) μmol/L in NICCD vs 112.0 (84.9-153.9) μmol/L in BA and 103.0 (70.9-135.3) μmol/L in INC, P = 0.0001]. The NICCD patients had significantly lower direct bilirubin [D-Bil 59.6 (43.1-90.9) μmol/L in NICCD vs 134.0 (115.9-151.2) μmol/L in BA and 87.3 (63.0-123.6) μmol/L in INC, P = 0.0001]; alanine aminotransferase [ALT 34.0 (23.0-55.0) U/L in NICCD vs 108.0 (62.0-199.0) U/L in BA and 84.5 (46.0-166.0) U/L in INC, P = 0.0001]; aspartate aminotransferase [AST 74.0 (53.5-150.0) U/L in NICCD vs 153.0 (115.0-239.0) U/L in BA and 130.5 (81.0-223.0) U/L in INC, P = 0.0006]; albumin [34.9 (30.7-38.2) g/L in NICCD vs 38.4 (36.3-42.2) g/L in BA and 39.9 (37.0-42.3) g/L in INC, P = 0.0001]; glucose [3.2 (2.0-4.4) mmol/L in NICCD vs 4.1 (3.4-5.1) mmol/L in BA and 4.0 (3.4-4.6) mmol/L in INC, P = 0.0014] and total cholesterol [TCH 3.33 (2.97-4.00) mmol/L in N ICCD vs 4.57 (3.81-5.26) mmol/L in BA and 4.00 (3.24-4.74) mmol/L in INC, P = 0.0155] levels. The D-Bil to total bilirubin (T-Bil) ratio was significantly lower in NICCD patients [all measures are expressed as median (inter-quartile range):0.54 (0.40-0.74)] than that in BA patients [0.77 (0.72-0.81), P = 0.001] and that in INC patients [0.74 (0.59-0.80), P = 0.0045]. A much higher AST/ALT ratio was found in NICCD patients [2.46 (1.95-3.63)] compared to BA patients [1.38 (0.94-1.97), P = 0.0001] and INC patients [1.48 (1.10-2.26), P = 0.0001]. NICCD patients had significantly higher TBA/D-Bil ratio [3.36 (1.98-4.43) vs 0.85 (0.72-1.09) in BA patients and 1.04 (0.92-1.14) in INC patients, P = 0.0001], and TBA/TCH ratio [60.7 (32.4-70.9) vs 24.7 (19.8-30.2) in BA patients and 24.2 (21.4-26.9) in INC patients, P = 0.0001] compared to the BA and INC groups. CONCLUSION:NICCD has significantly different bio- chemical indices from BA or INC. TBA excretion in NICCD appeared to be more severely disturbed than that of bilirubin and cholesterol.
基金supported by the National Natural Science Foundation of China(40830528 and 40710019002)
文摘Ammonia oxidizing （AOB） and denitrifying bacteria （DNB） play an important role in soil nitrogen transformation in natural and agricultural ecosystems. Effects of long-term fertilization on abundance and community composition of AOB and DNB were studied with targeting ammonia monooxygenase （amoA） and nitrite reductase （nirK） genes using polymerase chain reaction- denaturing gradient gel electrophoresis （PCR-DGGE） and real-time PCR, respectively. A field trial with different fertilization treatments in a rice paddy from Tai Lake region, centre East China was used in this study, including no fertilizer application （NF）, balanced chemical fertilizers （CF）, combined organic/inorganic fertilizer of balanced chemical fertilizers plus pig manure （CFM）, and plus rice straw return （CFS）. The abundances and riehnesses of amoA and nirK were increased in CF, CFM and CFS compared to NF. Principle component analysis of DGGE profiles showed significant difference in nirK and amoA genes composition between organic amended （CFS and CFM） and the non-organic amended （CF and NF） plots. Number of amoA copies was significantly positively correlated with normalized soil nutrient richness （NSNR） of soil organic carbon （SOC） and total nitrogen （T-N）, and that of nirK copies was with NSNR of SOC, T-N plus total phosphorus. Moreover, nitrification potential showed a positive correlation with SOC content, while a significantly lower denitrification potential was found under CFM compared to under CFS. Therefore, SOC accumulation accompanied with soil nutrient richness under long-term balanced and organic/inorganic combined fertilization promoted abundance and diversity of AOB and DNB in the rice paddy.
基金supported by the Chinese Nonferrous Guilin Research Institute of Geology for Mineral Resource (No.ky20101372000001)
文摘Muscovite mineral was roasted in different conditions.Rubidium leaching rate was a standard to examine the impact of various factors on calcination effect,including the agent types,roasting time,mass ratio,and roasting temperature.The results indicate that the best agent is the combination of sodium chloride and calcium chloride,and its mass ratio of muscovite/NaCl/CaCl2is1.00:0.25:0.25.Calcined at 850℃ for 30 min,the rubidium leaching rate is up to 90.12%.The reaction of muscovite ore with the chlorinating agent CaCl2was studied by TG/DSC,and the surface morphology before and after leaching was characterized by SEM.Rubidium chloride products can be obtained using t-BAMBP extraction,hydrochloric acid re-extraction,and purification.
文摘By means of ISM (Interpretative Structural Modeling) and SD (System Dynamics) methods, this paper made a system dynamics model of urbanization and eco-environment coupling in Jiangsu Province according to the implication and PSR (Pressure State Response) framework of urbanization and eco-environment coupling. Moreover, five typical scenarios during 2000-2015 have been simulated and analyzed based on the time serial statistical data during 1990-2003 in Jiangsu, which indicates: firstly, there are significant differences between the results and the scenarios, and the five coupling models all have comparative advantages and drawbacks; secondly, in terms of the characteristics and regional development disparities of Jiangsu and the general rule of world urbanization process, this paper reveals that only when either population urbanization model or social urbanization model to be correspondingly adopted, the sustainable development among population, economy, urbanization and eco-environment can be realized.
基金supported by the National Science Foundation of China(No.41272117)the Specialized Research Fund for the Doctoral Program of Higher Education of China(NO.20094116110002)Developing Projects of Science and Technology of Henan Province(NO.124300510039,092300410167)
文摘The biogenic sedimentary structures(i.e.,the morphology and trace makers of burrows,tracks,trails and traces made by extant organisms)and their composition and distribution characters in different micro environments and sub environments of the Yellow River delta in China are described.Three ichnocoenosis can be recognized:(1)Steinichnus-like ichnocoenosis,includes F,Y-shaped traces,birds'footprints on bedding plane,and Y,U-shaped burrows in intrastratal bedding,produced by Coleoptera(Heteroceridae),Orthoptera(Gryllotalpidae)and birds.It is majorly found at the delta plain point bar deposits,denoting the fresh water-related terrestrial environments.(2)Steinichnus-Psilonichnus-like ichnocoenosis,consitsis of Steinichnus-like traces on the bedding plane and Psilonichnus-like burrow which a vertical,irregularly J-,Y-,or U-shaped burrows,some of them with bulbous basal cells burrows in the intrastratal bedding,created by Coleoptera(Heteroceridae),Orthoptera(Gryllotalpidae)and crabs.It is observed in the delta plain abandoned distributary channels,and the delta front tidal creek and subaquous distributary channels,indicating the brackish water environment.(3)Palaeophycus-like ichnocoenosis,includes the round entrance burrows or with craters-shaped loop-protrusionsand and the parallel forked trails on the bedding plane,and the U,J or vertical shaped feeding burrows are in the intrastratal bedding,majorly produced by the clam(bivalve molluscs),gastropods and Nereis.It is present in the subaqueous interdistributary bay,reflecting the intertidal related environment.
基金This work was supported by grant from the Science and Technology Committee of Yunnan Province （2011 FB141 ） We thank Dr. Zhong-Bao ZHAO for helpful suggestions during manuscript preparation.
文摘The yellow meal worm （Tenebrio molitor L.） is an important resource insect typically used as animal feed additive. It is also widely used for biological research. The first complete mitochondrial genome of T. rnolitor was determined for the first time by long PCR and conserved primer walking approaches. The results showed that the entire mitogenome of T. molitor was 15 785 bp long, with 72.35% A＋T content [deposited in GenBank with accession number KF418153]. The gene order and orientation were the same as the most common type suggested as ancestral for insects. Two protein-coding genes used atypical start codons （CTA in ND2 and AAT in COX1）, and the remaining 11 protein-coding genes started with a typical insect initiation codon ATN. All tRNAs showed standard clover-leaf structure, except for tRNASer （AGN）, which lacked a dihydrouridine （DHU） arm. The newly added T. molitor mitogenome could provide information for future studies on yellow meal worm.
基金supported by National Natural Science Foundation of China[grant number 71273115]
文摘Foreign trade drives China's growth,but as the trade scale continues to expand,the carbon emissions also increase quickly.Based on the industry panel data from 1996 to 2010,this paper calculates carbon emissions of 27manufacturing industries.According to the intensity of carbon emissions,this paper divides the manufacturing sectors into low carbon and high carbon manufacturing industry and then analyzes the carbon emission trends.Next,the paper uses the feasible generalized least square regression to verify the existence of environmental Kuznets curve(EKC)of the manufacturing industry's carbon.In order to investigate the carbon leakage problem,the regression also includes the interaction term between trade and industrial value added.Our findings are as follows:the carbon emissions of the whole manufacturing industry and low carbon manufacturing industry accord with the EKC curve,but have a linear relationship with the high carbon manufacturing industry;trade reduces the carbon emissions of the whole manufacturing industry and low carbon manufacturing industry,but it increases those of the high carbon manufacturing industry;for the whole manufacturing industry and low carbon manufacturing industry,there is no carbon leakage,but it exists in the high carbon manufacturing industry.On the whole,pollution haven hypothesis does not hold up in China,and China does not need to limit industry foreign trade to reduce the emission of CO_2.But the manufacturing industry will still be the main engine of the economic growth,and therefore our country should make an effective low-carbon policy,introduce advanced technology,increase R&D investment into lowcarbon technologies,and upgrade and transform the original equipment to change the backward mode of production.
基金the Science and Technology Support Project of Jiangsu Province(Project No.BE2013711)for financially supporting this study
文摘The Taihu Lake region in East China has become prone to soil acidification, which changes heavy metals such as copper(Cu) in soil into water-soluble species and increases the mobility and contamination risks of heavy metals in the biological environment. In this study, the kinetics of Cu2+sorption by the bulk soil and the aggregate size fractions of an acidic paddy soil collected from the Taihu Lake region, the effects of temperature on Cu2+sorption, and the p H changes of the solution were investigated by static sorption and magnetic stirring. The aggregate size fractions were prepared by low-energy ultrasonic dispersing and freeze-drying. The total sorption amounts of the bulk soil and the aggregate size fractions for Cu2+followed a descending order of clay > coarse sand > bulk soil > silt> sand, corresponding to those of organic matter content, free iron oxide content, free aluminum oxide content, and cation exchange capacity. The kinetic sorption curves of Cu2+by the bulk soil and the aggregates, which were divided into two stages(rapid and slow sequentially), were well fitted by the first-order equation, the diffusion equation, and the Elovich equation, showing significant correlations(P < 0.05). Specific and non-specific sorption dominated in the fast and slow stages, respectively, and the former was predominant throughout the sorption process. The specific sorption accelerated and the non-specific sorption decelerated with rising temperature. The p H of the solution decreased significantly during the specific sorption and remained unchanged or increased slightly during the non-specific sorption. When the specific sorption terminated, the p H of the solution was minimized nearly simultaneously.The sorption progress of Cu2+by the bulk soil significantly preceded that by the aggregates. Therefore, heavy metal contamination may be another factor reducing soil p H and metal sorption forms should be taken into consideration in studies of mitigating soil heavy metal pollution or determining environmental capacity of heavy metal in soil.
文摘The chemical composition, the content and the leachability of heavy metals in municipal solid waste incineration （ MSWI） fly ash were tested and analyzed. It is shown that the leachability of Pb and Cr exceeds the leaching toxicity standard, and so the MSWI fly ash is considered as hazardous waste and must be solidifled. The effect of solidifying the MSWI fly ash by cement was studied, and it is indicated that the heavy metals can be well immobilized if the mass fraction of the fly ash is appropriate. The heavy metals were immobilized within cement hydration products through either physical fixation, substhtaion, deposition or adsorption mechanisms.
基金This work was financially supported by the National Natural Science Foundation of China (No.59995440).
文摘With the help of scanning electronic microscopy and X-ray diffraction, the relationships of microstructure characteristics, phase assemblage, and fracture micrograph of Al2O3/ZrO2 laminated ceramics were studied. Compared with monolithic Al2O3/ZrO2 ceramics, the existence of surface compressive stresses greatly restrained the growth of ZrO2 and Al2O3 grains at high sinter temperature, fined the grain size, and increased the content of metastable t-ZrO2, which made the fracture transformation energy quantity 70% higher than that of the monolithic ceramics. The trans-granular and inter-granular fracture features were observed in the surface and center layers, which further verified that transformation toughening is the main mechanism, whereas, micro-crack toughening is helpful for enhancing fracture toughness.
基金supported by National Natural Science Foundation of China—Shanxi coal based low carbon joint fund(U1610254)Shanxi Province Basic Applied Research Youth Fund(201801D221345)2018 Xiangyuan County Solid Waste Comprehensive Utilization Science and Technology Projects(2018XYSDYY-14)。
文摘Due to its low volatile characteristics of lean coal,it is difficult to catch fire and burn out.Therefore,high temperature is needed to maintain combustion efficiency,while,this leads to high nitrogen oxide emission.For power plant boilers burning lean coal,stable combustion with lower nitrogen oxide emission is a challenging task.This study applied the 3D numerical simulation on the analysis of a novel de-coupling burner for low-volatile coal and its structure and operation parameters optimization.Results indicate that although it was more difficult for lean coal decoupling burner to ignite lean coal than high volatile coal,the burner formed a stepwise ignition trend,which promoted the rapid ignition of lean coal.Comparison of three central partition plate structure shows that in terms of characteristics of the flow field distribution,rich and lean separation and combustion,the structure with an inclination of 0°showed good performance,with its rich-lean air ratio being 0.85 and concentration ratio being 22.94,and there was an apparent decoupling combustion characteristic.Finally,the structure of the selected burner was optimized for its operational conditions.The optimal operating parameters was determined as the primary air velocity of 24.9 m·s^-1 and the mass flow rate of pulverized coal of 2.5 kg·s^-1,in which the pyrolysis products were utilized as reductive agent more fully.Eventually,the nitrogen oxide was efficiently reduced to nitrogen,which emission concentration was 61.88%lower than that in the design condition.
