检索结果-南通市图书馆

A bibliometric analysis of carbon exchange in global drylands

Journal of Arid Land 2021年第11期13卷 1089-1102页

作者： LIU Zhaogang CHEN Zhi YU Guirui ZHANG Tianyou YANG Meng key laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China Yanshan Earth Critical Zone and surface Fluxes Research Station University of Chinese Academy of SciencesBeijing 101408China College of Grassland Agriculture Northwest A&F UniversityYangling 712100China

Drylands refer to regions with an aridity index lower than 0.65,and billions of people depend on services provided by the critically important ecosystems in these *** ecosystem carbon exchange in global drylands(CED)occurs and how climate change affects CED are critical to the global carbon ***,we performed a comprehensive bibliometric study on the fields of annual publications,marked journals,marked institutions,marked countries,popular keywords,and their temporal evolution to understand the temporal trends of CED research over the past 30 a(1991-2020).We found that the annual scientific publications on CED research increased significantly at an average growth rate of 7.93%.Agricultural water Management ranked first among all journals and had the most *** ten most productive institutions were centered on drylands in America,China,and Australia that had the largest number and most citations of publications on CED research."Climate change"and climate-related(such as"drought","precipitation","temperature",and"rainfall")research were found to be the most popular study *** were classified into five clusters,indicating the five main research focuses on CED studies:hydrological cycle,effects of climate change,carbon and water balance,productivity,and carbon-nitrogen-phosphorous coupling *** temporal evolution of keywords further showed that the areas of focus on CED studies were transformed from classical pedology and agricultural research to applied ecology and then to global change ecological research over the past 30 *** future CED studies,basic themes(such as"water","yield",and"salinity")and motor themes(such as"climate change","sustainability",and"remote sensing")will be the focus of research on *** particular,multiple integrated methods to understand climate change and ecosystem sustainability are potential new research trends and hotspots.

关键词： bibliometric analysis drylands carbon exchange climate change arid areas water resources sustainability

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Simulation and analysis of river runoff in typical cold regions

引用

Research in Cold and Arid Regions 2011年第6期3卷 498-508页

作者： QiuDong Zhao BaiSheng Ye YongJian Ding ShiQiang Zhang ChuanCheng Zhao Jian Wang ZengRu Wang Division of Hydrology and water-Land Resources in Cold and Arid Regions Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou Gansu 730000 China State key laboratory of Cryospheric Sciences Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences Lanzhou Gansu 730000 China Division of Hydrology and water-Land Resources in Cold and Arid Regions Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou Gansu 730000 China State key laboratory of Cryospheric Sciences Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences Lanzhou Gansu 730000 China

It is generally agreed that global warming is taking place, which has caused runoff generation processes and apparently total runoff amount changes in cold regions of Northwestern China. It is absolutely necessary to quantify and analyze earth surface hydrolog- ical processes by numerical models for formulating scientific sustainable development of water resources. Hydrological models became established tools for studying the hydrological cycle, but did not consider frozen soil or glacier hydrology. Thus, they should be improved to satisfy the simulation of hydrological processes in cold regions. In this paper, an energy balance glacier melt model was successfully coupled to the VIC model with frozen soil scheme, thus improving the models performance in a cold catchment area. We performed the improved VIC model to simulate the hydrological processes in the Aksu River Basin, and the simulated results are in good agreement with observed data. Based on modeling hydrological data, the runoff components and their response to climate change were analyzed. The results show：（1） Glacial meltwater recharge accounts fbr 29.2% of runoff for the Toxkan River, and 58.7% for the Kunma Like River. （2） The annual total runoffoftwo branches of the Aksu River show in- creasing trends, increased by about 43.1%, 25.75 X 106 m3 per year for the Toxkan River and by 13.1%, 14.09 ~ l06 m3 per year for the Kunma Like River during the latter 38 years. （3） The annual total runoff of the Toxkan River increased simply due to the increase of non-glacial runoff, while the increase of annual total runoff of the Kunma Like River was the result of increasing gla- cial （42%） and non-glacial runoff （58%）.

关键词： glacier energy and mass balance hydrologic model hydrologic process simulation Aksu River Basin

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Improvement of a Snow Albedo Parameterization in the Snow–Atmosphere–Soil Transfer Model:Evaluation of Impacts of Aerosol on Seasonal Snow Cover

引用

Advances in Atmospheric Sciences 2017年第11期34卷 1333-1345页

作者： Efang ZHONG Qian LI Shufen SUN Wen CHEN Shangfeng CHEN Debashis NATH Center for Monsoon System Research Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China University of Chinese Academy of Sciences Beijing 100049 China State key laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

The presence of light-absorbing aerosols （LAA） in snow profoundly influence the surface energy balance and water budget. However, most snow-process schemes in land-surface and climate models currently do not take this into consider- ation. To better represent the snow process and to evaluate the impacts of LAA on snow, this study presents an improved snow albedo parameterization in the Snow-Atmosphere-Soil on snow. Specifically, the Snow, Ice and Aerosol Radiation Transfer （SAST） model, which includes the impacts of LAA （SNICAR） model is incorporated into the SAST model with an LAA mass stratigraphy scheme. The new coupled model is validated against in-situ measurements at the Swamp Angel Study Plot （SASP）, Colorado, USA. Results show that the snow albedo and snow depth are better reproduced than those in the original SAST, particularly during the period of snow ablation. Furthermore, the impacts of LAA on snow are esti- mated in the coupled model through case comparisons of the snowpack, with or without LAA. The LAA particles directly absorb extra solar radiation, which accelerates the growth rate of the snow grain size. Meanwhile, these larger snow particles favor more radiative absorption. The average total radiative forcing of the LAA at the SASP is 47.5 W m-2. This extra radiative absorption enhances the snowmelt rate. As a result, the peak runoff time and ＂snow all gone＂ day have shifted 18 and 19.5 days earlier, respectively, which could further impose substantial impacts on the hydrologic cycle and atmospheric processes.

关键词： light-absorbing aerosols snow albedo SAST SNICAR

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Groundwater circulation relative to water quality and vegetation in an arid transitional zone linking oasis,desert and river

Groundwater circulation relative to water quality and vegeta...

引用

中国科学院地质与地球物理研究所2013年度（第13届）学术年会

作者： HUANG TianMing PANG ZhongHe CHEN YaNing KONG YanLong key laboratory of Engineering Geomechanics Institute of Geology and GeophysicsChinese Academy of Sciences State key laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of Sciences

In groundwater-dependent ecosystems,groundwater circulation controls the overall water quality and ecosystem dynamics. Groundwater and vegetation across a 30-km groundwater transect linking oasis,desert and river in an extremely arid area were investigated with a series of soil profiles drilled into the unsaturated zone to understand groundwater circulation and its control on groundwater quality and surface vegetation in the extremely arid Lower Tarim River,NW *** have included water-table depth,water chemistiy and water isotopes(H,O,H) for 15 water samples,soil moisture and chloride content for 11 soil profiles,and vegetation *** show that the groundwater in desert zone is characterized by slow recharge rate(pre-modern water),great water-table depth(6.17-9.43 m) and high salinity(15.32-26.50 g/L),while that in oasis(uncultivated land) and riparian zone is characterized by relatively fast recharge rate(modern water),small groundwater-table depth (3.56-8.36 m) and low salinity(1.25-1.95 g/L).Stable isotopes show that secondary evaporation takes place during irrigation in *** vegetation characteristics(coverage,richness,evenness and number of plants) are closely related to soil moisture and water-table *** recharge from irrigation in oasis and from river in riparian zone sustains a better ecosystem than that in the desert area,where lateral and vertical groundwater recharge is *** more evapotranspirative enrichment may occur in the vegetated and water-rich riparian zone as compared to *** study also demonstrates the effectiveness of environmental tracers in studying ecohydrological processes in arid regions.

关键词： isotope soil profile riparian zone ecosystem salinity arid zone hydrology

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Assessing the Quality of Regional Ocean Reanalysis Data from ENSO Signals

引用

Atmospheric and Oceanic Science Letters 2012年第1期5卷 55-61页

作者： WANG Lu ZHOU Tian-Jun State key laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics （LASG） Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Graduate University of the Chinese Academy of Sciences Beijing 100029 China

The quality of regional ocean reanalysis data for ＂the joining area of Asia and the Indian-Pacific Ocean （AIPO）＂ has been assessed from the perspective of ENSO-related ocean signals. The results derived from the AIPO reanalysis, including SST, sea surface height （SSH）, and subsurface ocean temperature and currents, are compared with those of Hadley Center Sea Ice and Sea surface Temperature （HadlSST） data set and Simple Ocean Data Assimilation （SODA） reanalysis data. Both the spatial pattern and the characteristics of evolution of the ENSO-related ocean temperature anomalies are well reproduced by the AIPO reanalysis data. The physical processes proposed to explain the life cycle of ENSO, including the delayed oscillator mechanism, recharge-discharge mechanism, and the zonal advection feedback, are reasonably represented in this dataset. However, the westward Rossby wave signal in 1992 is not obvious in the AIPO data, and the magnitude of the heat content anomalies is different from that of the SODA data. The reason for the discrepancies may lie in the different mod- els and methods for data assimilation and differences in wind stress forcing. The results demonstrate the high reliability of the AIPO reanalysis data in describing ENSO signals, implying its potential application value in ENSO- related studies.

关键词： reanalysis data ENSO ocean assimilation AIPO data

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Mechanism of slope failure in loess terrains during spring thawing

引用

Journal of Mountain Science 2018年第4期15卷 845-858页

作者： XU Jian WANG Zhang-quan REN Jian-wei WANG Song-he JIN Long School of Civil Engineering Xi'an University of Architecture and Technology Xi'an 710055 China Institute of Geotechnical Engineering Xi'an University of Technology Xi'an 710048 China State key laboratory of Road Engineering Safety and Health in Cold and High-altitude Region CCCC First Highway Consultants Co. Ltd. Xi'an 710075 China

Slope failure in loess terrains of Northern China during spring thawing period is closely related to the freeze-thaw cycling that surface soils inevitably experienced. Field surveys were carried out on natural and artificial slopes in thirteen surveying sites located in the Northern Shaanxi, the center of Loess Plateau, covering five characteristic topographic features including tablelands, ridges, hills, gullies and valleys. Based on the scale that is involved in freeze-thaw cycling, the induced failures can be classified into three main modes, i.e., erosion, peeling and thaw collapse, depending on both high porosity and loose cementation of loess that is easily affected. Model tests on loess slopes with gradients of 53.1°, 45.0° and 33.7° were carried out to reveal the heat transfer, water migration and deformation during slope failure. The surface morphology of slopes was photographed, with flake shaped erosion and cracks noted. For three slope models, time histories for the thermal regime exhibit three obvious cycles of freeze and thaw andthe maximum frost depth develops downwards as freeze-thaw cycling proceeds. Soil water in the unfrozen domain beneath was migrated towards the slope surface, as can be noticed from the considerable change in the unfrozen water content, almost synchronous with the variation of temperature. The displacement in both vertical and horizontal directions varies over time and three obvious cycles can be traced. The residual displacement for each cycle tends to grow and the slopes with higher gradients are more sensitive to potentially sliding during freeze-thaw cycling.

关键词： Freeze and thaw Loess Slope failure water migration Heat transfer

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Rotational Mechanism of Ammonium Ion in water and Methanol

引用

Chinese Journal of Chemical Physics 2018年第4期31卷 568-574,616页

作者： Qiang Zhang Yang Du Chen Chen Wei Zhuang Department of Chemistry Bohai UniversityJinzhou 121013China State key laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of SciencesFuzhou 350002China

Dynamics of ammonium and ammonia in solutions is closely related to the metabolism of arnrnoniac compounds, therefore plays an important role in various biological processes. NMR measurements indicated that the reorientation dynamics of NH4＋ is faster in its aqueous solution than in rnethanol, which deviates from the Stokes-Einstein-Debye rule since water has higher viscosity than methanol. To address this intriguing issue, we herein study the reorientation dynamics of ammonium ion in both solutions using numerical simulation and an extended cyclic Markov chain model. An evident decoupling between translation and ro- tation of methanol is observed in simulation, which results in the deviation of reorientation from the Stokes-Einstein-Debye rule. Slower hydrogen bond （HB） switchings of ammonium with rnethanol comparing to that with water, due to the steric effect of the rnethyl group, remarkably retards the jump rotation of ammonium. The observations herein provide useful insights into the dynamic behavior of ammonium in the heterogeneous environments including the protein surface or protein channels.

关键词： Ammonium Jump rotation Hydrogen bond switching Methanol Moleculardynamics sirnulation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Quantifying the Cloud water Resource:Methods Based on Observational Diagnosis and Cloud Model Simulation

引用

Journal of Meteorological Research 2020年第6期34卷 1256-1270页

作者： Miao CAI Yuquan ZHOU Jianzhao LIU Chao TAN Yahui TANG Qianrong MA Qi LI Jietai MAO Zhijin HU CMA key laboratory for Cloud Physics Chinese Academy of Meteorological SciencesChina Meteorological Administration(CMA)Beijing 100081 State key laboratory of Severe Weather Chinese Academy of Meteorological SciencesCMABeijing 100081 Jilin Weather Modification Office Changchun 130062 Nanjing University of Information Science&Technology Nanjing 210044 School of Physics Peking UniversityBeijing 100871

Based on the concepts of cloud water resource(CWR)and related variables proposed in the first part of this study,this paper provides details of two methods to quantify the *** is diagnostic quantification(CWR-DQ)based on satellite observations,precipitation products,and atmospheric reanalysis data;and the other is numerical quantification(CWR-NQ)based on a cloud resolving model developed at the Chinese Academy of Meteorological Sciences(CAMS).The two methods are applied to quantify the CWR in April and August 2017 over North China,and the results are evaluated against all available *** results are as follows.(1)For the CWR-DQ approach,reference cloud profiles are firstly derived based on the Cloud Sat/CALIPSO joint satellite observations for 2007–*** NCEP/NCAR reanalysis data in 2000–2017 are then employed to produce three-dimensional cloud *** budget/balance equations of atmospheric water substance are lastly used,together with precipitation observations,to retrieve CWR and related *** is found that the distribution and vertical structure of clouds obtained by the diagnostic method are consistent with observations.(2)For the CWR-NQ approach,it assumes that the cloud resolving model is able to describe the cloud microphysical processes completely and precisely,from which four-dimensional distributions of atmospheric water vapor,hydrometeors,and wind fields can be *** data are then employed to quantify the CWR and related terms/*** one-month continuous integration,the mass of atmospheric water substance becomes conserved,and the tempospatial distributions of water vapor,hydrometeors/cloud water,and precipitation are consistent with observations.(3)Diagnostic values of the difference in the transition between hydrometeors and water vapor(Cvh-Chv)and the surface evaporation(Es)are well consistent with their numerical values.(4)Correlation and bias analyses show that the diagnostic CWR contributors are well co

关键词： cloud water resource(CWR) atmospheric hydrometeors precipitation efficiency quantification method observation diagnosis cloud model simulation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The role of earthquake-induced landslides in erosion and weathering from active mountain ranges:Progress and perspectives

引用

Science China Earth Sciences 2021年第12期64卷 2069-2082页

作者： Zhangdong JIN Robert G.HILTON AJoshua WEST Gen K.LI Fei ZHANG Jin WANG Gaojun LI Xuanmei FAN Meng-Long HSIEH State key laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi’an710061China Institute of Global Environmental Change Xi’an Jiaotong UniversityXi’an710049China Department of Geography Durham UniversityDurhamDH13LEUK Department of Earth Sciences University of Southern CaliforniaLos AngelesCA90089USA Division of Geological and Planetary Sciences California Institute of TechnologyPasadenaCA91125USA School of Land Engineering Chang’an UniversityXi’an710054China Department of Earth and Planetary Sciences Nanjing UniversityNanjing210023China State key laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu610059China Department of Earth and Environmental Sciences Taiwan Chung Cheng UniversityChiayi600China

Earthquakes play a fundamental role in the evolution of Earth’s topography through co-seismic uplift and subsidence,as well as erosion through widespread landslides induced by ground ***-induced landslides can result in exceptional increases in the transfer of mass from landscapes,supplying sediment to rivers where impacts can last for decades or *** can also erode vegetation and soils,in addition to exposing freshly ground rock mass,which can both result in regionally significant carbon *** work has sought to quantify the fluxes,rates,and temporal patterns of the impacts on earth surface processes generated by these tectonic *** this review,we focus on the impacts of earthquake-induced landslides on erosion and sediment flux,river water chemistry,and carbon export through the lens of the well-studied 2008 Wenchuan *** then discuss these themes in the context of works from the 1999 Taiwan Chi-Chi earthquake,2015 Nepalese Gorkha earthquake,and New Zealand historical earthquakes,altogether highlighting an important role of earthquake-induced landslides in erosion and weathering along tectonically active mountain *** suggest that more monitoring,geochemical tracing,paleo-records,and/or modelling studies are needed to compare the processes and fluxes of catchment erosion and weathering before and after earthquake events,which will help to deepen our understanding not only of the impacts of earthquake-induced landslides on earth surface processes,but also the linkage among high magnitude events,continental erosion and weathering,and the long-term global carbon cycle.

关键词： Earthquake Erosion Chemical weathering The carbon cycle Tectonically active mountain ranges

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Testing the model for linking grain-size component to lake level status of modern clastic lakes

Testing the model for linking grain-size component to lake l...

引用

中国科学院地质与地球物理研究所2015年度（第15届）学术年会

作者： Jule Xiao Jiawei Fan Dayou Zhai Ruilin Wen Xiaoguang Qin key laboratory of Cenozoic Geology and Environment Institute of Geology and Geophysics Chinese Academy of Sciences

A model was proposed recently for linking grain-size component to lake level status based on investigations of Daihai Lake in Inner Mongolia. To test this model, grain-size components of the surface sediments of Dali Lake, 500 km northeast of Daihai Lake, were partitioned and their relationships with the lake level status were examined in this study. The data show that modern clastic sediments of Dali Lake contain five distinct grain-size components representing specific depositional processes and sedimentary environments within the lake in common with Daihai Lake. These components are specified as long-term suspension clay, offshore-suspension fine silt, offshore-suspension medium-to-coarse silt,nearshore-suspension fine sand and nearshore-saltation medium sand. In Dali Lake, by contrast, the offshore-suspension components are lacking in more samples from the nearshore zone;the nearshoresuspension and saltation components occur in more samples from the offshore and transitional zone,respectively;and two adjacent components are well separated. These differences would result from higher-energy hydraulics of Dali Lake generated by stronger and more frequent winds occurring in the lake region. Under this hydraulic condition, clastic materials entering the lake and the resultant components would be reworked more seriously during transportation within the lake, leading to further basin-ward transportations of the major components and better separations of two adjacent components. Percentage of the nearshore components is negatively related to water depth, suggesting the grain-size componentelake level status model for the lake. This model was applied to a sediment core from the lake, showing that high percentages of the nearshore components in the core coincide with low precipitations reconstructed on the pollen profile of the same core. The coincidence of two independent proxies demonstrates the wide applicability of the grain-size componentelake level status model to l

关键词： Dali Lake Polymodal sediment Grain-size component Lake-level status Model

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：