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Coupling analysis of social-economic water consumption and its effects on the arid environments in Xinjiang of China based on the water and ecological footprints 预览
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作者 ZHANG Pei DENG Mingjiang +5 位作者 LONG Aihua DENG Xiaoya WANG Hao HAI Yang WANG Jie LIU Yundong 《干旱区科学:英文版》 SCIE CSCD 2020年第1期73-89,共17页
In arid areas,ecological degradation aroused by over-exploitation of fresh water,expansion of artificial oasis and shrinkage of natural oasis,has drawn attention of many scholars and officials.The water and ecological... In arid areas,ecological degradation aroused by over-exploitation of fresh water,expansion of artificial oasis and shrinkage of natural oasis,has drawn attention of many scholars and officials.The water and ecological footprints can be used to quantitatively evaluate the water consumption of social-economic activities and their influence on the eco-environments.In addition,increase of the water footprint indicates the expansion of artificial oasis,and the influence on the natural oasis could be reflected by the variation of the ecological footprint.This study was conducted to answer a scientific question that what is the quantitative relationship between the expansion of the artificial oasis and the degradation of the natural oasis in the arid environments of Xinjiang,China.Thus,based on the social-economic data,water consumption data and meteorological data during 2001–2015,we calculated the water and ecological footprints to express the human-related pressure exerted on the water resources and arid environments in Xinjiang(including 14 prefectures and cities),and explore the relationship between the water and ecological footprints and its mechanism by using the coupling analysis and Granger causality test.The results show that both the water and ecological footprints of Xinjiang increased significantly during 2001–2015,and the increasing rate of the ecological footprint was much faster than that of the water footprint.The coupling degree between the water and ecological footprints was relatively high at the temporal scale and varied at the spatial scale.Among the 14 prefectures and cities examined in Xinjiang,the greater social-economic development(such as in Karamay and Urumqi)was associated with the lower coupling degree between the two footprints.Increases in the water footprint will cause the ecological footprint to increase,such that a 1-unit increase in the consumption of water resources would lead to 2–3 units of ecological degradation.The quantitative relationship between the increases of the wate 展开更多
关键词 water consumption ecological footprint water footprint Granger causality test natural oasis artificial oasis Tarim River
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Recent Progress of Atmospheric Water Harvesting Using Metal-Organic Frameworks
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作者 PAN Tingting YANG Kaijie HAN Yu 《高等学校化学研究:英文版》 SCIE CAS CSCD 2020年第1期33-40,共8页
Atmospheric water harvesting based on vapor adsorption is a newly emerged and potential technology to supply portable water for arid areas.To efficiently harvest vapor from the air,sorbents are required to have consid... Atmospheric water harvesting based on vapor adsorption is a newly emerged and potential technology to supply portable water for arid areas.To efficiently harvest vapor from the air,sorbents are required to have conside-rable adsorption capacity,easy regeneration and high stability.With the advantages of porous structure,tunable pore size and tailorable hydrophilicity,metal-organic frameworks(MOFs)have demonstrated excellent performance in vapor adsorption and water generation.In this review,we first discuss the degradation mechanisms of MOFs exposed to water and summarize the structure-stability relationship;by centering on the adsorption isotherms,the connection between the structure of MOFs and the water adsorption property is illuminated;finally,some prospects are suggested in order to push forward the progress of this technology. 展开更多
关键词 Metal organic framework Atmospheric water harvesting Hydrolytic stability Water adsorption isotherm
Promoting the Construction of Beautiful and Rich China with the Theory of Soil and Water Ecology 预览
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作者 Fazheng SUN 《气象与环境研究:英文版》 CAS 2020年第2期20-24,共5页
Started from the problems and perplexities of ecological environment in China,the scientific principle and value of the theory of soil and water ecology are discussed. It is thought that the theory of soil and water e... Started from the problems and perplexities of ecological environment in China,the scientific principle and value of the theory of soil and water ecology are discussed. It is thought that the theory of soil and water ecology clarifies the complicated problems of ecological environment. Environmental pollution can be controlled,but it is only a matter of time and cost. Soil and water ecology is the root of ecological environment problems. The clean water and green mountain are destroyed,which cannot be restored. With the theory of soil and water ecology,the idea that clean water and green mountain are golden and silver mountains is read,as well as the way of turning clean water and green mountain into golden and silver mountains and its different impacts on eco-environment. The developed and underdeveloped areas should treat the idea that clean water and green mountain are golden and silver mountains. The application of the theory of soil and water ecology in soil and water conservation broadens the space of soil and water conservation,and it is necessary to establish a national commission for the conservation of soil and water ecology. The theory of soil and water ecology is the golden key to solve the problems of contemporary ecological environment and the theoretical basis for building a beautiful and rich China. 展开更多
关键词 Ecological environment Soil and water ecology Clean water and green mountain Golden and silver mountains Beautiful and rich
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《老子》“玄”与“玄德”新释
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作者 尚永亮 朱春洁 《复旦学报:社会科学版》 CSSCI 北大核心 2020年第1期40-47,共8页
"玄"与"玄德"是《老子》中非常重要的两个概念,历来解说者众,然多一间有隔。从文化发生学和五行说的角度看,所谓"玄德"即"水德",而"玄"除后起的玄妙诸义外,主要指水或水之特性:其黑... "玄"与"玄德"是《老子》中非常重要的两个概念,历来解说者众,然多一间有隔。从文化发生学和五行说的角度看,所谓"玄德"即"水德",而"玄"除后起的玄妙诸义外,主要指水或水之特性:其黑而兼赤之色给人幽昧深妙之感,其本身既为万物之始又兼具生生不息之性。在某种意义上可以说,"玄"与"玄德"就是以母体和女性生命力为旨归的"水德"哲学。与此相关,"玄牝"指深幽莫测可以容水之母体,"玄鉴"是践行"水德"的重要方式,"玄通""玄同"则成为"水德"在世间万物中的呈现状态。仔细辨析、认知这些概念及其关联,可以从本源处深化对老子哲学的理解。 展开更多
关键词 “玄” “玄德” 水德 母体
Stable oxygen-hydrogen isotopes reveal water use strategies of Tamarix taklamakanensis in the Taklimakan Desert,China 预览
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作者 DONG Zhengwu LI Shengyu +3 位作者 ZHAO Ying LEI Jiaqiang WANG Yongdong LICongjuan 《干旱区科学:英文版》 SCIE CSCD 2020年第1期115-129,共15页
Tamarix taklamakanensis,a dominant species in the Taklimakan Desert of China,plays a crucial role in stabilizing sand dunes and maintaining regional ecosystem stability.This study aimed to determine the water use stra... Tamarix taklamakanensis,a dominant species in the Taklimakan Desert of China,plays a crucial role in stabilizing sand dunes and maintaining regional ecosystem stability.This study aimed to determine the water use strategies of T.taklamakanensis in the Taklimakan Desert under a falling groundwater depth.Four typical T.taklamakanensis nabkha habitats(sandy desert of Tazhong site,saline desert-alluvial plain of Qiemo site,desert-oasis ecotone of Qira site and desert-oasis ecotone of Aral site)were selected with different climate,soil,groundwater and plant cover conditions.Stable isotope values of hydrogen and oxygen were measured for plant xylem water,soil water(soil depths within 0–500 cm),snowmelt water and groundwater in the different habitats.Four potential water sources for T.taklamakanensis,defined as shallow,middle and deep soil water,as well as groundwater,were investigated using a Bayesian isotope mixing model.It was found that groundwater in the Taklimakan Desert was not completely recharged by precipitation,but through the river runoff from snowmelt water in the nearby mountain ranges.The surface soil water content was quickly depleted by strong evaporation,groundwater depth was relatively shallow and the height of T.taklamakanensis nabkha was relatively low,thus T.taklamakanensis primarily utilized the middle(23%±1%)and deep(31%±5%)soil water and groundwater(36%±2%)within the sandy desert habitat.T.taklamakanensis mainly used the deep soil water(55%±4%)and a small amount of groundwater(25%±2%)within the saline desert-alluvial plain habitat,where the soil water content was relatively high and the groundwater depth was shallow.In contrast,within the desert-oasis ecotone in the Qira and Aral sites,T.taklamakanensis primarily utilized the deep soil water(35%±1%and 38%±2%,respectively)and may also use groundwater because the height of T.taklamakanensis nabkha was relatively high in these habitats and the soil water content was relatively low,which is associated with the reduced groundwater depth due 展开更多
关键词 Tamarix taklamakanensis water use strategies stable isotopes Bayesian isotope mixing model deep soil water groundwater Taklimakan Desert
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Applying multivariate statistics for identification of groundwater chemistry and qualities in the Sugan Lake Basin, Northern Qinghai-Tibet Plateau, China
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作者 XIANG Juan ZHOU Jun-ju +6 位作者 YANG Jun-cang HUANG Mei-hua FENG Wei LI Qiao-qiao XUE Dong-xiang ZHAO Ya-ru ZHU Guo-feng 《山地科学学报:英文版》 SCIE CSCD 2020年第2期448-463,共16页
The Sugan Lake Basin is located in the inland arid region of northwestern China,in which groundwater is of great significance to human and ecology.Therefore,it is necessary to understand the chemical characteristics a... The Sugan Lake Basin is located in the inland arid region of northwestern China,in which groundwater is of great significance to human and ecology.Therefore,it is necessary to understand the chemical characteristics and quality of groundwater in the basin.Based on samples collected from 35 groundwater wells in Sugan Lake Basin,the spatial distribution characteristics of groundwater chemistry,main hydrogeochemical processes and groundwater quality have been discussed in this paper by using the multivariate statistics and hydrochemistry analysis methods.The results showed that the groundwater is weakly alkaline,and its total dissolved solid(TDS)and total hardness(TH) are high,with the average values of 1244.03 mg/L and 492.10 mg/L,respectively.The types of groundwater are mainly HCO_3~--SO_4~(2-)-Ca~(2+)type in the runoff area and Cl~--SO_4~(2-)-Na~+type in the catchment area.Rock weathering and ion exchange are the main controlling factors of regional groundwater chemistry,followed by evaporative crystallization,and human activities have less impact on groundwater.The spatial difference of groundwater quality is obvious,the water quality of the catchment area is not suitable for drinking,and the suitability for plant growth is also poor.The groundwater in the runoff area can be used for drinking,but the hardness is slightly higher,which is more suitable for ecological purpose. 展开更多
关键词 HYDROCHEMISTRY GROUNDWATER Water quality assessment Sugan Lake Basin Water quality TIBET
Effect of slope gradient on the subsurface water flow velocity of sand layer profile
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作者 HAN Zhen CHEN Xiao-yan +3 位作者 HUANG Yu-han LUO Bang-lin XING Hang HUANG Yong-chao 《山地科学学报:英文版》 SCIE CSCD 2020年第3期641-652,共12页
Subsurface water flow velocity influences the hydrodynamic characteristics of soil seepage and the interaction between subsurface water flow and surface runoff during soil erosion and sediment transport.A visualized m... Subsurface water flow velocity influences the hydrodynamic characteristics of soil seepage and the interaction between subsurface water flow and surface runoff during soil erosion and sediment transport.A visualized method and equipment was adopted in this study to observe the subsurface water flow.Quartz sand was used as the test material of subsurface water flow and fluorescent dye was used as the indicator for tracing subsurface water flow.Water was supplied at the same flow discharge to the three parts at the bottom of the test flume,and the subsurface water flow were determined with four slope gradients(4°,8°,10°,and 12°).The results showed that the seepage velocity gradually increased with increasing slope gradient.The pore water velocity at different depths of sand layer profile increased with increasing slope gradient,whereas the thickness of the flow front gradually decreased.For the same slope gradient,the pore water velocity in the lower layer was the largest,whereas the thickness of the flow front was the smallest.Comparative analysis of the relationship between seepage velocity and pore water velocity at different depths of sand layer profile showed that the maximum relative difference between the measured pore water velocity and the computational pore water velocity at different depths of sand profile in the experiment was 4.38%.Thus,the test method for measuring the subsurface water flow velocity of sand layer profile adopted in this study was effective and feasible.The development of this experiment and the exploration of research methods would lay a good test foundation for future studies on the variation law of subsurface water flow velocity and the determination of flow velocity in purple soils,thus contributing to the improvement of the hydrodynamic mechanism of purple soils. 展开更多
关键词 Subsurface water flow Pore water velocity Seepage velocity Slope gradient Sand layer
Revealing the changes of bacterial community from water source to consumers tap:A full-scale investigation in eastern city of China
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作者 Xu Ma Guiwei Li +4 位作者 Ruya Chen Ying Yu Hui Tao Guangming Zhang Baoyou Shi 《环境科学学报:英文版》 SCIE EI CAS CSCD 2020年第1期331-340,共10页
This study profiled the bacterial community variations of water from four water treatment systems,including coagulation,sedimentation,sand filtration,ozonation-biological activated carbon filtration(O3-BAC),disinfecti... This study profiled the bacterial community variations of water from four water treatment systems,including coagulation,sedimentation,sand filtration,ozonation-biological activated carbon filtration(O3-BAC),disinfection,and the tap water after the distribution process in eastern China.The results showed that different water treatment processes affected the bacterial community structure in different ways.The traditional treatment processes,including coagulation,sedimentation and sand filtration,reduced the total bacterial count,while they had little effect on the bacterial community structure in the treated water(before disinfection).Compared to the traditional treatment process,O3-BAC reduced the relative abundance of Sphingomonas in the finished water.In addition,ozonation may play a role in reducing the relative abundance of Mycobacterium.NaClO and ClO2 had different effects on the bacterial community in the finished water.The relative abundance of some bacteria(e.g.Flavobacterium,Phreatobacter and Porphyrobacter)increased in the finished water after ClO2 disinfection.The relative abundance of Mycobacterium and Legionella,which have been widely reported as waterborne opportunistic pathogens,increased after NaClO disinfection.In addition,some microorganisms proliferated and grew in the distribution system,which could lead to turbidity increases in the tap water.Compared to those in the finished water,the relative abundance of Sphingomonas,Hyphomicrobium,Phreatobacter,Rheinheimera,Pseudomonas and Acinetobacter increased in the tap water disinfected with NaClO,while the relative abundance of Mycobacterium increased in the tap water disinfected with ClO2.Overall,this study provided the detailed variation in the bacterial community in the drinking water system. 展开更多
关键词 Bacterial community Water treatment process Drinking water distribution system Opportunistic pathogen
Target inhibition of caspase-8 alleviates brain damage after subarachnoid hemorrhage 预览
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作者 Da-Qiang Ke Zhi-Yang Chen +2 位作者 Zhou-Ling Li Xia Huang Hui Liang 《中国神经再生研究:英文版》 SCIE CAS CSCD 2020年第7期1283-1289,共7页
Caspase-8 plays an important role in the mediation of inflammation and the effect of its role in subarachnoid hemorrhage remains elusive.The nucleotide-binding oligomerization domain-like receptor protein 3 inflammaso... Caspase-8 plays an important role in the mediation of inflammation and the effect of its role in subarachnoid hemorrhage remains elusive.The nucleotide-binding oligomerization domain-like receptor protein 3 inflammasome has been postulated to mediate inflammation during SAH.The aim of the present study was to investigate the effects of caspase-8 inhibition on SAH injury and further elucidate the molecular mechanisms.In this study,a subarachnoid hemorrhage model was established by endovascular perforation process in adult male Sprague-Dawley rats.Z-IETD-FMK(0.5,1,2 mg/kg;an inhibitor of caspase-8)was delivered via intravenous(tail vein)injection immediately after subarachnoid hemorrhage.After 12 hours of subarachnoid hemorrhage,western blot assay showed that the expression of cleaved caspase-8 was significantly increased at 12 hours,peaked at 24 hours,and then decreased at 72 hours after subarachnoid hemorrhage.Immunofluorescence staining demonstrated that caspase-8 was expressed in microglia after subarachnoid hemorrhage.Z-IETDFMK significantly improved neurological deficits and reduced brain water content 24 hours after subarachnoid hemorrhage.The Morris water maze and rotarod test confirmed that Z-IETD-FMK significantly improved spatial learning and memory abilities and motor coordination at 21–27 days after subarachnoid hemorrhage.Furthermore,inhibition of caspase-8 activation reduced the expression of pyrin domain-containing 3,caspase-1,and interleukin-1βafter subarachnoid hemorrhage.In conclusion,our findings suggest that caspase-8 inhibition alleviates subarachnoid hemorrhage-induced brain injuries by suppressing inflammation.The study was approved by the Institutional Animal Ethics Committee of the First Affiliated Hospital,School of Medicine,Zhejiang University,China(approval No.2016-193)on February 25,2016. 展开更多
关键词 brain WATER content CASPASE-8 inflammation Morris WATER maze neurological function neuroprotection PYRIN domain-containing 3 ROTAROD test SUBARACHNOID hemorrhage Z-IETD-FMK
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Comprehensive Analytical Study of the Greenhouse Effect of the Atmosphere 预览
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作者 Peter Stallinga 《大气和气候科学(英文)》 2020年第1期40-80,共41页
Climate change is an important societal issue. Large effort in society is spent on addressing it. For adequate measures, it is important that the phenomenon of climate change is well understood, especially the effect ... Climate change is an important societal issue. Large effort in society is spent on addressing it. For adequate measures, it is important that the phenomenon of climate change is well understood, especially the effect of adding carbon dioxide to the atmosphere. In this work, a theoretical fully analytical study is presented of the so-called greenhouse effect of carbon dioxide. The effect of this gas in the atmosphere itself was already determined as being of little importance based on empirical analysis. In the current work, the effect is studied both phenomenologically and analytically. In a first attempt of energy transfer by radiation only, it is solved by ideal-gas-law equations and the atmosphere is divided into an infinite number of layers each absorbing and reemitting infrared radiation (surpassing the classical Beer-Lambert analysis of absorption). The result is that the exact structure of the atmosphere is irrelevant for the analysis;we might as well keep the two-box model for any analytical approach. However, the results are unsatisfactory in that they cannot explain the profile of the atmosphere. In a new approach, the atmosphere is solved by taking both radiative as well as thermodynamic processes into account. The model fully fits the empirical data and an analytical equation is given for the atmospheric behavior. Upper limits are found for the greenhouse effect ranging from zero to a couple of mK per ppm CO2. It is shown that it cannot explain the observed correlation of carbon dioxide and surface temperature. This correlation, however, is readily explained by Henry’s Law (outgassing of oceans), with other phenomena insignificant. Finally, while the greenhouse effect can thus, in a rudimentary way, explain the behavior of the atmosphere of Earth, it fails describing other atmospheres such as that of Mars. Moreover, looking at three cities in Spain, it is found that radiation balances only cannot explain the temperature of these cities. Finally, three data sets with different time scales (60 years, 展开更多
关键词 GREENHOUSE Effect THERMODYNAMICS Radiation BALANCE Correlation FEEDBACK Water Carbon Dioxide MARS VENUS Earth
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载玻片表面修饰胺基聚合物的合成及表征
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作者 肖凌寒 崔庆实 +1 位作者 刘旭东 周钰 《化工新型材料》 CAS CSCD 北大核心 2020年第2期85-88,共4页
聚丙烯酰胺(PAM)经三步反应被很好地接枝到载玻片上,又特别针对反应体系中水对产物形貌的影响做了研究。通过使用X射线光电子能谱(XPS)、原子力显微镜(AFM)和扫描电镜(SEM)等手段对成功接枝PAM后的玻片进行测试。结果表明:反应体系中水... 聚丙烯酰胺(PAM)经三步反应被很好地接枝到载玻片上,又特别针对反应体系中水对产物形貌的影响做了研究。通过使用X射线光电子能谱(XPS)、原子力显微镜(AFM)和扫描电镜(SEM)等手段对成功接枝PAM后的玻片进行测试。结果表明:反应体系中水的存在与否,会导致两种差异很大的结构和组成成分,水存在时,载玻片上生成了形貌结构为两层的胺基聚合物,且上层胺基密度不一。水不存在时,其表面生成了单层分子结构的胺基聚合物,同时其密度更加均一。 展开更多
关键词 载玻片 聚丙烯酰胺 胺基聚合物 结构
Effect of water-driven changes in rice rhizosphere on Cd lability in three soils with different pH
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作者 Jinjin Wang Dongqin Li +4 位作者 Qin Lu Yulong Zhang Huijuan Xu Xueli Wang Yongtao Li 《环境科学学报:英文版》 SCIE EI CAS CSCD 2020年第1期82-92,共11页
Pot experiments were conducted to evaluate the effect of water management,namely continuous flooding(CF),intermittent flooding(IF)and non-flooding(NF),on Cd phytoavailaility in three paddy soils that differed in p H a... Pot experiments were conducted to evaluate the effect of water management,namely continuous flooding(CF),intermittent flooding(IF)and non-flooding(NF),on Cd phytoavailaility in three paddy soils that differed in p H and in Cd concentrations.Diffusive gradients in thin films(DGT)technique was employed to monitor soil labile Cd and Fe concentrations simultaneously at three growth stages(tillering,heading and mature stage)of rice.The Cd phytoavailability were generally in the order of NF>IF>CF,and higher rice Cd(over permitted level,0.2 mg/kg)were only found in neutral and acidic soils under NF conditions.DGT measured soil labile Cd rather than total Cd was the most reliable predictor for Cd accumulation in rice.CF enhanced the formation of root plaques,which related to oxidation of large quantities of available Fe on root surfaces due to the O2 secretion of rice root.The Cd concentration in root plaques shared the same trend with DGT-Cd.Generally,root plaques would inhibit Cd uptake by rice under CF conditions,while under IF and NF conditions,root plaques act as a temporarily store of Cd,and soil labile Cd is the key factor that controls the transfer of Cd from soil to rice.The results of principle component analysis revealed that water management had the greatest effect on soil Cd lability and rice Cd in acidic soil.Thus,it is important to consider the availability of Cd and soil p H when assessing current agricultural practices of contaminated soil in China. 展开更多
关键词 Cadmium lability RHIZOSPHERE Rice Water management Root plaque DGT technique
Application of brassinolide alleviates cold stress at the booting stage of rice 预览
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作者 WANG Shi-qiang ZHAO Hai-hong +5 位作者 ZHAO Li-ming GU Chun-mei NA Yong-guang XIE Bao-sheng CHENG Shi-hua PAN Guo-jun 《农业科学学报:英文版》 SCIE CAS CSCD 2020年第4期975-987,共13页
The objective of the study was to determine the physiological mechanisms of plants in response to brassinolide(BR) alleviating cold water stress on rice. In this study, physiological responses of rice to exogenous BR ... The objective of the study was to determine the physiological mechanisms of plants in response to brassinolide(BR) alleviating cold water stress on rice. In this study, physiological responses of rice to exogenous BR and cold water submergence were investigated using the chilling-tolerant cultivar Kongyu 131(KY131) and the chilling-sensitive cultivar Kenjiandao 6(KJD6). A total of 2 mg L^-1 BR increased activities of superoxide dismutase(SOD) and peroxidase(POD) and the contents of soluble sugar, soluble protein, and chlorophyll, but decreased the malondialdehyde(MDA) content in KY131 and KJD6 under cold water stress. The observed decreases in SOD and POD activities and MDA content recovered quickly after plants were returned to irrigation with water at temperatures of about 23.0°C in 2014. Additionally, the contents of nitrogen(N), phosphorous(P), and potassium(K) were increased by BR treatment under cold water stress. Exposure to BR also raised the percentage of high effective leaf area and leaf area index at the heading stage. Furthermore, it promoted soluble sugar synthesis, increased the rate of dry matter accumulation, and enhanced the export and translocation rates of the stem-sheath. The yield in KJD6 was significantly(P≤0.01 and P≤0.05) higher than that of the control in 2013 and 2014, respectively. The effect of BR treatment on rice leaf SOD and POD activities, MDA, chlorophyll, P, and stem-sheath K contents were more significant in KJD6 than in KY131. In conclusion, exogenous BR effectively reduced the physiological and metabolic damage in rice due to cold stress at the booting stage, promoted functional recovery in plants that received irrigation with water at a normal temperature following cold stress, and mitigated the effects of cold water stress on yield.The two varieties exhibited differential responses to BR;the weaker cold-resistant variety was more sensitive to BR and displayed stronger responses to exogenous BR. 展开更多
关键词 RICE cold water stress BRASSINOLIDE physiological characteristics
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Water sorption thermodynamics in glassy polymers endowed with hydrogen bonding interactions
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作者 G.Scherillo P.La Manna +1 位作者 P.Musto G.M ensitieri 《中国科学:物理学、力学、天文学英文版》 SCIE EI CAS CSCD 2020年第4期136-154,共19页
In this contribution, we review and critically compare the results of the analyses we have previously performed on water sorption thermodynamics in a series of polyimides. The experimental investigation was performed ... In this contribution, we review and critically compare the results of the analyses we have previously performed on water sorption thermodynamics in a series of polyimides. The experimental investigation was performed by combining gravimetric tests and in situ vibrational spectroscopy. A non-equilibrium theory, based on a compressible lattice framework accounting for the glassy state of the polymer and for the occurrence of hydrogen bonding interactions, has been used to interpret data. Information at a molecular level gained by vibrational spectroscopy has been used to tailor the model equations. The main features of water sorption thermodynamics are well captured, qualitatively and quantitatively, by the adopted model which displays a remarkable agreement with experimental results. 展开更多
关键词 WATER polyimides sorption thermodynamics
离子液体萃取剂辅助分离乙腈+水共沸物 预览
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作者 李进龙 石俸铭 +1 位作者 李婷婷 疏其朋 《常州大学学报:自然科学版》 CAS 2020年第1期14-21,共8页
乙腈和水在一定压力下可形成具有最低温度的共沸混合物,普通精馏方法无法将其有效分离,必须采用萃取精馏等特殊分离技术。鉴此,通过实验测定乙腈+水+1-乙基-3-甲基咪唑乙醇酸盐([EMIM][GAC])三元汽液平衡(VLE)数据,证实离子液体[EMIM][G... 乙腈和水在一定压力下可形成具有最低温度的共沸混合物,普通精馏方法无法将其有效分离,必须采用萃取精馏等特殊分离技术。鉴此,通过实验测定乙腈+水+1-乙基-3-甲基咪唑乙醇酸盐([EMIM][GAC])三元汽液平衡(VLE)数据,证实离子液体[EMIM][GAC]在一定条件下可消除乙腈和水混合物的共沸性。借助NRTL模型,获得了二元交互作用参数,关联温度和汽相组成绝对平均偏差分别为0.67 K和0.0078。基于Aspen Plus软件平台,建立了萃取精馏双塔流程,比较了萃取剂[EMIM][GAC]和乙二醇(EG)萃取精馏分离效果,结果表明[EMIM][GAC]作为萃取剂使溶剂物质的量比从0.94降至0.20、萃取精馏塔加热负荷降低9.4%,同时分离塔的理论级数从53降至20。 展开更多
关键词 萃取精馏 离子液体 乙腈 共沸混合物
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Self-supported Ni2P nanosheets on low-cost three-dimensional Fe foam as a novel electrocatalyst for efficient water oxidation 预览
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作者 Mengrong Zhang Taotao Wang +2 位作者 Hongyun Cao Shengsheng Cui Pingwu Du 《能源化学:英文版》 SCIE EI CAS CSCD 2020年第3期71-76,共6页
Electrochemical water splitting into hydrogen and oxygen is a promising strategy for future renewable energy conversion devices.The oxygen evolution reaction(OER)is considered as the bottleneck reaction in an overall ... Electrochemical water splitting into hydrogen and oxygen is a promising strategy for future renewable energy conversion devices.The oxygen evolution reaction(OER)is considered as the bottleneck reaction in an overall water splitting system because it involves 4e- and 4H+ transfer processes.Currently,it is highly desirable to explore low-cost alternative catalysts for OER at ambient conditions.Herein,we report for the first time that nickel phosphide(Ni2P)nanosheets can be facilely grown on Fe foam(FF)as an efficient electrocatalyst for OER with excellent durability and catalytic activity under alkaline conditions.To reach a current density of 10 m A/cm2,the Ni2P-FF catalyst required a low overpotential of only 198 mV for OER.The catalyst’s high OER activity and durability were well maintained at a high current density.The required overpotentials were only 267 and 313 mV to achieve the current densities of 100 and 300 m A/cm2,respectively.The combination of low-cost Fe foam with Ni2P provides a promising low-cost catalyst for large-scale application of electrocatalytic water splitting. 展开更多
关键词 LOW-COST ELECTROCATALYST Metal PHOSPHIDE FE foam Water oxidation
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气候变化与农业活动对中国开都河流域下游水质的影响
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作者 巴乌龙 杜鹏飞 +4 位作者 刘铁 包安明 陈曦 刘蛟 秦成新 《地理学报:英文版》 SCIE CSCD 2020年第1期164-176,共13页
In the context of climate change and over-exploitation of water resources,water shortage and water pollution in arid regions have become major constraints to local sustainable development.In this study,we established ... In the context of climate change and over-exploitation of water resources,water shortage and water pollution in arid regions have become major constraints to local sustainable development.In this study,we established a Soil and Water Assessment Tool(SWAT)model for simulating non-point source(NPS)pollution in the irrigation area of the lower reaches of the Kaidu River Basin,based on spatial and attribute data(2010-2014).Four climate change scenarios(2040-2044)and two agricultural management scenarios were input into the SWAT model to quantify the effects of climate change and agricultural management on solvents and solutes of pollutants in the study area.The simulation results show that compared to the reference period(2010-2014),with a decline in streamflow from the Kaidu River,the average annual irrigation water consumption is expected to decrease by 3.84×10^8 m^3 or 8.87%during the period of 2040-2044.Meanwhile,the average annual total nitrogen(TN)and total phosphorus(TP)in agricultural drainage canals will also increase by 10.50%and 30.06%,respectively.Through the implementation of agricultural management measures,the TN and TP in farmland drainage can be reduced by 14.49%and 16.03%,respectively,reaching 661.56 t and 12.99 t,accordingly,and the increasing water efficiency can save irrigation water consumption by 4.41×10^8 m^3 or 4.77%.The results indicate that although the water environment in the irrigation area in the lower reaches of the Kaidu River Basin is deteriorating,the situation can be improved by implementing appropriate agricultural production methods.The quantitative analysis results of NPS pollutants in the irrigation area under different scenarios provide a scientific basis for water environmental management in the Kaidu River Basin. 展开更多
关键词 CLIMATE change AGRICULTURAL management non-point POLLUTANTS SWAT Kaidu River BASIN water quality
Distribution of Protists in the Deep South China Sea Revealed by High-Throughput Sequencing 预览
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作者 LI Xinran WARREN Alan +1 位作者 JIAO Nianzhi XU Dapeng 《中国海洋大学学报:英文版》 SCIE CAS CSCD 2020年第1期161-170,共10页
Protists(microbial eukaryotes)are indispensable members of the marine microbial food web.In recent years,organisms living in the deep sea(>1000 m water depth)have increasingly become the focus of research;however,s... Protists(microbial eukaryotes)are indispensable members of the marine microbial food web.In recent years,organisms living in the deep sea(>1000 m water depth)have increasingly become the focus of research;however,studies on protistan assemblages are relatively scarce compared with their prokaryotic counterparts.In the present study,high-throughput sequencing of the hypervariable V9 region of the 18S rRNA gene was used to explore the community composition of protists in bathypelagic waters of the South China Sea.Based on the analysis of the alpha and beta diversities of 14 samples,we discovered:1、members belonging to Rhizaria,Alveolata,and Excavata were the dominant groups in terms of both relative sequence abundance and operational taxonomic unit(OTU)richness in all samples,although their relative contributions differed among different samples;2、cluster analysis showed that the distribution of protistan assemblages was related neither to the sampling location nor to the water depth,and other environmental factors might have caused the differences among the communities;3、phototrophs,including members of the Bacillariophyta,Bolidophyceae,Dictyochophyceae,Prasinophyceae,and Prymnesiophyceae,were detected in all samples,which indicated their contributions to the downward transportation via the biological pump and the potential presence of phagotrophy of these phototrophic cells in the deep ocean. 展开更多
关键词 bathypelagic water DIVERSITY microbial eukaryotes SSU rRNA gene
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Model test of the influence of cyclic water level fluctuations on a landslide
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作者 HE Chun-can HU Xin-li +3 位作者 XU Chu WU Shuang-shuang ZHANG Han LIU Chang 《山地科学学报:英文版》 SCIE CSCD 2020年第1期191-202,共12页
Many landslides in reservoir areas continuously deform under cyclic water level fluctuations due to reservoir operations. In this paper,a landslide model, developed for a typical colluvial landslide in the Three Gorge... Many landslides in reservoir areas continuously deform under cyclic water level fluctuations due to reservoir operations. In this paper,a landslide model, developed for a typical colluvial landslide in the Three Gorges Reservoir area, is used to study the effect of cyclic water level fluctuations on the landslide. Five cyclic water level fluctuations were implemented in the test, and the fluctuation rate in the last two fluctuations doubled over the first three fluctuations. The pore water pressure and lateral landslide profiles were obtained during the test. A measurement of the landslide soil loss was proposed to quantitatively evaluate the influence of water level fluctuations. The test results show that the first water level rising is most negative to the landslide among the five cycles. The fourth drawdown with a higher drawdown rate caused further large landslide deformation. An increase of the water level drawdown rate is much more unfavorable to the landslide than an increase of the water level rising rate. In addition, the landslide was found to have an adaptive ability to resist subsequent water level fluctuations after undergoing large deformation during a water level fluctuation. The landslide deformation and observations in the field were found to support the test results well. 展开更多
关键词 Reservoir landslide Cyclic water level fluctuations Physical model test Landslide soil loss Adaptive ability
水相中镍催化微波辅助合成喹唑啉酮衍生物的反应 预览
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作者 李震 刘圣亚 +3 位作者 李飞 孔迎春 翁维 王斌 《化学研究与应用》 CAS CSCD 北大核心 2020年第2期292-296,共5页
建立了一种以氯化镍与脯氨酸锂作为催化剂,在水相中即可简单、高效地以2-卤代苯甲酰胺和脒类盐酸盐合成喹唑啉酮衍生物的方法。该方法具有操作简便,无毒的特点,成本低廉,并且所有底物均能以较高的产率得到喹唑啉酮类衍生物,最高产率达91%。
关键词 喹唑啉酮 氯化镍 2-卤代苯甲酰胺 脒盐 水相
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