检索结果-南通市图书馆

Soil loss tolerance in the black soil region of Northeast China

Journal of Geographical Sciences 2012年第4期22卷 737-751页

作者： DUAN Xingwu XIE Yun LIU Baoyuan LIU Gang FENG Yanjie GAO Xiaofei Asian international rivers Center Yunnan Key Laboratory of International Rivers and Transboundary Eco-securityYunnan UniversityKunming 650091China State Key Laboratory of Earth Surface Processes and Resource ecology School of GeographyBeijing Normal UniversityBeijing 100875China

Soil loss tolerance （/） is the maximum rate of annual soil erosion that is tolerated and still allows a high level of crop productivity to be sustained economically and indefinitely. In the black soil region of Northeast China, an empirically determined, default Tvalue of 200 （t/km2.a） is used for designing land restoration strategies for different types of soils. The ob- jective of this study was to provide a methodology to calculate a quantitative T for different black soil species. A field investigation was conducted to determine the typical soil profiles of 21 black soil species in the study area and a quantitative methodology based on a modified soil productivity index model was established to calculate the Tvalues. These values, which varied from 68 t/km2.a to 358 t/km2-a, yielded an average Tvalue of 141 t/km2.a for the 21 soil species. This is 29.5% lower than the current national standard T value. Two significant factors that influenced the T value were soil thickness and vulnerability to erosion. An acceptable reduction rate of soil productivity over a planned time period of 1% is recommended as necessary for maintaining long-term sustainable soil productivity. Compared with the cur- rently used of regional unified standard T value, the proposed method, which determines T using specific soil profile indices, has more practical implications for effective, sustainable management of soil and water conservation.

关键词： soil loss tolerance quantitative approach productivity index model soil erosion vulnerability index black soil species black soil region of Northeast China

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

Analysis and prediction of sediment trapping efficiencies of the reservoirs in the mainstream of the Lancang River

引用

Chinese Science Bulletin 2007年第A02期52卷 134-140页

作者： FU KaiDao HE DaMing Asian international rivers Center Yunnan University Kunming 650091 China

存储的水和水库套住的沉积在下游的水路环境上导致物理、化学、生态的效果。关于水库沉积的量的研究是钥匙估计它的环境影响。在位于 Manwan 水库的 upstream 和 downstream 的计量车站在 39 年获得的沉积负担数据被用来估计 Manwan 水... 详细信息

存储的水和水库套住的沉积在下游的水路环境上导致物理、化学、生态的效果。关于水库沉积的量的研究是钥匙估计它的环境影响。在位于 Manwan 水库的 upstream 和 downstream 的计量车站在 39 年获得的沉积负担数据被用来估计 Manwan 水坝的套住的效率(TE ) 。TE 价值当时与用修改 Brune 和 Siyam 模型的估计相比。结果显示那：(1 ) 计量数据估计的 Manwan 水坝的 TE 是 60.48% ，并且两个都， TE 值由修改 Brune 计算了， Siyam 模型是 60.03% 。近似 TE 价值显示修改 Brune 和 Siyam 模型能被用来在 Lancang 河的主流作为 Manwan 水库与类似的存储能力预报另外的水库的 TE；(2 ) Gongguoqiao， Dachaoshan 和 Jinghong 水坝的 TE 价值是大约 30.23% ， 66.05% 和 63.50% 由修改 Brune 模型估计了，并且 38.81% ， 63.97% 和 62.30% 由修改 Siyam 当模特儿。在论文采用的结果和方法论能也被用来在西南的中国在另外的河盆估计 TE。

关键词：分析方法澜沧江水库沉积物

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Transboundary eco-security and its regulation system in the Longitudinal Range-Gorge Region

引用

Chinese Science Bulletin 2007年第A02期52卷 1-9页

作者： HE DaMing LIU Jiang HU JinMing FEN Yan GAN Su Asian international rivers Center Yunnan University Kunming 650091 China

这份报纸讨论了 transboundary eco 安全问题，他们的分发模式，特征和驱动力，和在纵的范围峡区域(LRGR ) 的规定系统。除了沙灰尘暴风雨，主要 transboundary eco 安全问题能在 LRGR 沿着中国的陆上的边阶区域被发现。直接驱动力包括... 详细信息

这份报纸讨论了 transboundary eco 安全问题，他们的分发模式，特征和驱动力，和在纵的范围峡区域(LRGR ) 的规定系统。除了沙灰尘暴风雨，主要 transboundary eco 安全问题能在 LRGR 沿着中国的陆上的边阶区域被发现。直接驱动力包括了串联水力发出的电力水坝，高速公路和国际航行开发的构造，斜坡陆地耕作和矿物质探索。Transboundary eco 安全问题沿着国际水路在陆上的区域，和下游的国家影响附近的区域。在邻国的生态的变化在 LRGR 在国内方面上有效果，例如种类侵略。综合措施应该被考虑，包括边阶 eco 保护工程和 transboundary 自然保护区的构造，生态的阀值安装，种类侵略控制，监视平台的 eco 安全的建立，组成生态的赔偿机制和法律(规则) 并且机构，和能力大楼。在 LRGR 处理 transboundary 问题的最重要的任务是国际性地形成参与合作机制，为 transboundary eco 安全建立资金，实现生态的赔偿策略，并且开发信息交换站台和警告系统。

关键词：生态系统纵向岭谷区分配模式生态安全

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Climate change adaptation, greenhouse gas mitigation and economic profitability of conservation agriculture: Some examples from cereal systems of Indo-Gangetic Plains

引用

Journal of Integrative Agriculture 2015年第8期14卷 1524-1533页

作者： Tek B Sapkota M L Jat Jeetendra P Aryal R K Jat Arun Khatri-Chhetri international Maize and Wheat Improvement Center Borlaug institute for South Asia Consultative Group of international Agricultural Research (CGIAR) Research Program on Climate Change Agriculture and Food Security (CCAFS) International Water Management Institute

Achieving sustainability of the cereal system in the Indo-Gangetic Plains（IGP）of India under progressive climate change and variability necessitates adoption of practices and technologies that increase food production,adaptation and mitigation in a sustainable *** paper examines conservation agriculture（CA）from the perspective of：（i）increased yield and farm income,（ii）adaptation to heat and water stresses,and（iii）reduction in greenhouse gas（GHGs）*** analyses and conclusions are based on the literature and evidences from a large number of on-station as well as farmers’field trials on CA in the cereal systems of *** analyses show that CA-based system substantially reduces the production cost（up to 23%）but produces equal or even higher than conventional system;thereby increasing economic profitability of production ***-based production systems also moderated the effect of high temperature（reduced canopy temperature by 1–4°C）and increased irrigation water productivity by 66–100%compared to traditional production systems thus well adapting to water and heat stress situations of *** continuous monitoring of soil flux of CO2,N2O and CH4 revealed that CA-based rice-wheat systems emit 10–15%less GHGs than conventional *** is the first time that CA and its components are synthesized and analyzed from food security-climate change *** this holistic analysis,we suggest that wide-scale promotion of suitable CA practices by integrating into national agriculture development strategy is a way forward to address food security,climate change adaptation and mitigation challenges faced by present agriculture.

关键词： zero-tillage residue retention climate change sustainability conservation agriculture

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

Microscopic Analysis of Cementitious Sand and Gravel Damming Materia

引用

Fluid Dynamics & Materials Processing 2024年第4期20卷 749-769页

作者： Ran Wang Aimin Gong Shanqing Shao Baoli Qu Jing Xu Fulai Wang Feipeng Liu College of Water Conservancy Yunnan Agricultural UniversityKunming650201China Tianqi Engineering Consulting Co. Ltd.Kunming650000China institute of international rivers and ecological security Yunnan UniversityKunming650500China

The mechanical properties of cementitious sand and gravel damming material have been experimentally determined by means of microscopic SEM(Scanning Electron Microscopy)image *** results show that the combination of fly ash and water can fill the voids in cemented sand and gravel test blocks because of the presence of hydrated calcium silicate and other substances;thereby,the compactness and mechanical properties of these materials can be greatly *** every 10 kg/m^(3) increase in the amount of cementitious material,the density increases by about 2%,and the water content decreases by 0.2%.The amount of cementitious material used in the sand and gravel in these tests was 80-110 kg/m^(3),the water-binder ratio was ***,the splitting tensile strength was 1/10 of the compressive strength,and the maximum strength was 7.42 MPa at 90 *** optimal mix ratio has been found to be 50 kg of cement,60 kg of fly ash and 120 kg of water(C50F60W120).The related dry density was 2.6 g/cm^(3),the water content was 6%,and the water-binder ratio was 1.09.

关键词： Cementitious sand gravel material scanning electron microscopy optimal mix ratio maximum strength

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Mechanism of Downcutting Erosion of Debris Flow over a Movable Bed

引用

Journal of Mountain Science 2015年第1期12卷 243-250页

作者： Pan Hua-li Huang Jiang-cheng Ou Guo-qiang Key Laboratory of Mountain Hazards and Earth Surface Process Institute of Mountain Hazards and Environment CAS Asian international rivers Center Yunnan University

The phenomenon of debris flow is intermediate between mass movement and solid transport. Flows can be sudden, severe and destructive. Understanding debris flow erosion processes is the key to providing geomorphic explanations, but progress has been limited because the physical-mechanical properties, movement laws and erosion characteristics are different from those of sediment-laden flow. Using infinite slope theory, this research examines the process and mechanism of downcutting erosion over a moveable bed in a viscous debris flow gully. It focuses specifically on the scour depth and the critical slope for viscous debris flow,and formulas for both calculations are *** scour depth and the critical conditions of downcutting erosion are related to debris flow properties(sand volume concentration and flow depth) and gully properties(longitudinal slope,viscous and internal friction angle of gully materials,and coefficient of kinetic friction). In addition, a series of flume experiments was carried out to characterize the scouring process of debris flows with different properties. The calculated values agreed well with the experimental data. These theoretical formulas are reasonable, and using infinite slope theory to analyze down cutting erosion from viscous debris flow is feasible.

关键词： Debris flow Down cutting erosion Infinite slope theory Critical conditions Flumeexperiments

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

Influence of transboundary air pollution on air quality in southwestern China

引用

Geoscience Frontiers 2021年第6期12卷 114-128页

作者： Xiufeng Yin Shichang Kang Maheswar Rupakheti Benjamin de Foy Ping Li Junhua Yang Kunpeng Wu Qianggong Zhang Dipesh Rupakheti State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and ResourcesChinese Academy of ScienceLanzhou 730000China Key Laboratory of Tibetan Environment Changes and Land Surface Processes Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100039China CAS Center for Excellence in Tibetan Plateau Earth Sciences Beijing 100085China institute for Advanced Sustainability Studies PotsdamGermany Department of Earth and Atmospheric Sciences Saint Louis UniversitySt.LouisMO 63108USA Northwest institute of eco-Environment and Resources Chinese Academy of ScienceLanzhou 730000China institute of international rivers and eco-security Yunnan UniversityKunming 650091China

Air pollution is a grand challenge of our time due to its multitude of adverse impacts on environment and society,with the scale of impacts more severe in developing countries,including ***,China has initiated and implemented strict air pollution control measures over last several years to reduce impacts of air *** data from Jan 2015 to Dec 2019 on six criteria air pollutants(SO_(2),NO_(2),CO,O_(3),PM_(2.5),and PM_(10))at eight sites in southwestern China were investigated to understand the situation and analyze the impacts of transboundary air pollutants in this *** terms of seasonal variation,the maximum concentrations of air pollutants at these sites were observed in winter or spring season depending on individual *** diurnal variation,surface ozone peaked in the afternoon while the other pollutants had a bimodal pattern with peaks in the morning and late *** was limited transport of domestic emissions of air pollutants in China to these *** emissions enhanced the concentrations of air pollutants during some pollution ***,the transboundary transport of air pollution from South Asia and Southeast Asia was associated with high concentrations of most air pollutants observed in southwestern *** air pollutants can be transported to southwestern China over long distances from the source regions,it is necessary to conduct more research to properly attribute and quantify transboundary transport of air pollutants,which will provide more solid scientific guidance for air pollution management in southwestern China.

关键词： Air pollutants Transboundary transport Southwestern China

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

Root-order-associated variations in fine-root decomposition and their effects on soil in a subtropical evergreen forest

引用

ecological Processes 2022年第1期11卷 654-668页

作者： Yibo Wu Mengling Zhang Zhibao Cheng Fang Wang Xiaoyong Cui School of Civil and Environment Engineering Ningbo UniversityNingbo 315211China institute of international rivers and eco-security Yunnan UniversityKunming 650504China College of Life Sciences University of Chinese Academy of SciencesBeijing 100049China Environmental Futures Research institute School of Environment and ScienceGriffith UniversityBrisbane 4111Australia Beijing Yanshan Earth Critical Zone National Research Station University of Chinese Academy of SciencesBeijing 101408China

Background:Despite the importance of root decomposition in predicting ecosystem responses to future climate change,the effects of branch order on root decomposition and the feedback to soil still remains poorly *** we separated root samples taken from two tree species(Castanopsis fargesii and Schima superba in subtropical forests along the coastal area in eastern China)into four-order classes(1st–2nd order,3rd order,4th order,and 5th order)and conducted a 540-day litterbag incubation experiment in laboratory to examine root mass loss,nutrient release,and the influence on soil during ***:*** roots of 1st–2nd and 3rd order decayed more slowly than those of 4th and 5th order,but this pattern was not significant for *** all the measured root traits,the decomposition rates correlated best with root C/N ratio,diameter and specific root length(SRL)based on the structural equation *** tree species and root order exhibited significantly effects on root initial ***,*** roots decay faster than ***,and this appears to be associated with root initial C quality and N *** addition,root order positively affected root decomposition rates mainly through root diameter and ***,no significant difference was found in C and N content between soils below the litterbag with different-order ***:Our findings suggest the effects of branch order on root decomposition are dependent on tree ***,root morphological properties might also be the controlling factor in root decay besides root chemistry ***,the integrative effects should be considered to improve our understanding of the fate of fine-root litter and their contribution to soil C and N pool.

关键词： Root branch Mass loss Initial quality Subtropical evergreen tree Soil carbon

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

Organic Matter Accumulation in the Upper Permian Dalong Formation from the Lower Yangtze Region,South China

引用

Acta Geologica Sinica(English Edition) 2024年第1期98卷 150-167页

作者： FANG Chaogang ZHANG Chengcheng MENG Guixi XU Jinlong XU Naicen LI Hualing LIU Mu LIU Bo institute of international rivers and eco-security Yunnan UniversityKunming 650500China Nanjing Center China Geological SurveyNanjing 210016China Exploration Research institute Anhui Provincial Bureau of Coal GeologyHefei 230088China China United Coalbed Methane Corporation Ltd. Beijing 100015China Geological Survey of Anhui Province Hefei 230001China Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China

The Late Permian was marked by a series of important geological events and widespread organic-rich black shale depositions,acting as important unconventional hydrocarbon source ***,the mechanism of organic matter(OM)enrichment throughout this period is still *** on geochemical data,the marine redox conditions,paleogeographic and hydrographic environment,primary productivity,volcanism,and terrigenous input during the Late Permian in the Lower Yangtze region have been studied from the Putaoling section,Chaohu,to provide new insights into OM *** Phases are distinguished based on the TOC and environmental *** Phase I,anoxic conditions driven by water restriction enhanced OM *** Phase II,euxinic and cycling hydrological environments were the two most substantial controlling factors for the massive OM *** Phase III,intensified terrestrial input potentially diluted the OM in sediment and the presence of oxygen in bottom water weakened the preservation *** IV was characterized by a relatively higher abundance of mercury(Hg)and TOC(peak at 16.98 wt%),indicating that enhanced volcanism potentially stimulated higher productivity and a euxinic *** Phase V,extremely lean OM was preserved as a result of terrestrial dilutions and decreasing primary *** I,II and IV are characterized as the most prominent OM-rich zones due to the effective interactions of the controlling factors,namely paleogeographic,hydrographic environment,volcanism,and redox conditions.

关键词： geochemistry redox condition primary productivity OM accumulation Lopingian/Changhsingian Lower Yangtze region

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

Progress and Future Development of Lancang-Mekong Cooperation

引用

国际问题研究 2018年第3期 199-215页

作者： Liu Qing Department for Asia-Pacific security and Cooperation China Institute of International Studies (CIIS)

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

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：