检索结果-南通市图书馆

Physical mechanisms of plant roots affecting weathering and leaching of loess soil

Science china Earth Sciences 2006年第9期49卷 1002-1008页

作者： LI Yong1,2. ZHANG Qingwen1,2. WAN Guojiang3, HUANG Ronggui3, PIAO Hechun3, BAI Lingyu2.& LI Lu2.1. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, institute of Soil and Water Conservation, chinese {2. of Sciences, Yangling 712.00, china 2. institute of agro-environment and sustainable development, chinese {2. of agricultural Sciences, Beijing 100081, china 3. institute of Geochemistry, chinese {2. of Sciences, Guiyang 550002. china 1. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water Conservation Chinese Academy of Sciences Yangling 712100 China 2. institute of agro-environment and sustainable development Chinese Academy of Agricultural Sciences Beijing 100081 China 3. institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China

Plant roots have potential impacts on soil mineral weathering and *** objective is to understand the physical mechanisms of plant roots affecting weathering andleaching of loess soil. Root densities were measured through the method of a large-size dug profile,and transport fluxes of soil elements were determined using an undisturbed monolith soilinfiltration device on the hilly and gully regions of the chinese Loess Plateau. The results showthat the improvement effects of soil environment by plant roots are mainly controlled by the densityand weight of the fibrous roots with the diameters less than 1 mm. Plant roots have the strongereffects on soil physical properties than chemical properties. The principal components analysis(PCA) indicates that soil physical properties by plant roots account for 56.7% of variations in soilenvironment whereas soil chemical properties and pH contribute about 2..2. of the soil *** roles of plant roots in controlling soil weathering and leaching increased in the followingorder: infiltration enhancement > increase of bio-active substance > stabilization of soilstructure. The effects of plant roots on soil mineral weathering and leaching can be quantifiedusing the multiple regression models with the high prediction accuracies developed in this study.

关键词： plant roots, soil weathering and leaching rates, soil environment field, principal components analysis (PCA), chinese Loess Plateau.

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

Towards sustainable mining cities: what policies should be sought and experiences could be learnt for china?

引用

Journal of Geographical Sciences 1999年第3期9卷 207-227页

作者： SHEN Lei, Ray Hudson(1. Centre for Resource Economy and development, Commission for Integrated Survey of NaturalResources, chinese {2. of Sciences, Beijing 100101, china 2. Department of Geography,University of Durham, South Road, Durham DH1 3LE, UK)

This paper aims to explore interinks between population, resoures, environment anddevelopment of mining cities in{2.. The authors place emphasis on speeific policy stud of how tostep a sustainable rnining city based on the analysis of six components constituting the integrative andsystendc backdrop to mining city sustainability. The attempts are taken to make a deep comparisonbased on the studies in the five typical cities of Datong, Daqing, Panzhihua, Jinchang and Golmud ofchina, combining some experiences and theorehca thoughts from the Western countries. Therelationship between the resourees endoment, mining (in broader sense) and economic developmentis given based on the analysis of development of mineral resources and formahon of mining ***, some changing characteristics and related issues of{2.'s mining cities on environmentand socio-econondc dimensions are considered. The last part of the paper focuses on the discussion ofrestructuring approach to the mining cities in{2., some reflections and suggestions are put forward.

关键词： mineral resources sustainable development mining city energy

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

Impact of land-use change on hydrological processes in the Maying River basin, china

引用

Science china Earth Sciences 2006年第10期49卷 1098-1110页

作者： WANG Genxu1,3, ZHANG Yu2. LIU Guimin2.& CHEN Lin3 1. institute of Mountain Hazards and environment, {2. academy of Sciences, Chengdu 610041, china 2. Cold and Arid Regions environmental and Engineering Research institute, {2. academy of Sciences, Lanzhou 730000, china 3. Resource and environment School, Lanzhou University, Lanzhou 730000, china 1. institute of Mountain Hazards and environment Chinese Academy of Sciences Chengdu 610041 China 3. Resource and environment School Lanzhou University Lanzhou 730000 China 2. Cold and Arid Regions environmental and Engineering Research institute Chinese Academy of Sciences Lanzhou 730000 China

Since the 1960s, dramatic changes have taken place in land-use patterns characterized by the persistent expansion of cultivated land and a continuous decrease in natural woodland and grassland in the arid inland river basins of china. It is very important to assess the effects of such land-use changes on the hydrological processes so vital for water resource management and sustainable {2. on the catchment scale. The Maying River catchment, a typical arid inland watershed located in the middle of the Hexi Corridor in northwest china, was the site chosen to investigate the hydrological responses to land-use changes. The annual runoff, base flow, maximum peak flow, and typical seasonal runoff in both spring and autumn flood periods were selected as the variables in the hydrological processes. Statistical-trend analysis and curvilinear regression were utilized to detect the trends in hydrological variables while eliminating the climatic influence. The relationship between cultivated land-use and hydrological variables was analyzed based on four periods of land-use variation data collected since 1965. A runoff model was established composed of two factors, i.e., cultivated land use and precipitation. The impact of land use changes, especially in the large ar- eas of upstream woodland and grassland turned into cultivated lands since 1967, has resulted in a mean annual runoff decrease of 2..12., a base flow decline of 35.32., a drop in the maximum peak discharge of 35.77%, and mean discharge decreases in spring and autumn of 36.05% and 2..87% respectively, of which the contribution of cultivated land expansion to the influence of annual runoff amounts to 77%-80%, with the contribution to the influence of spring discharge being 73%-81%, and that to the influence of base flow reaching 62.-65%. Thus, a rational regulation policy of land use patterns is vitally important to the sustainable use of water resources and the proper {2. of the entire catchment.

关键词： land-use change, arid inland river catchment, hydrological process, impact, Maying River.

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

Approach Analyses to Promote sustainable Forest Management with Forest Certification in china

引用

chinese Forestry Science and Technology 2008年第3期7卷 25-31页

作者： ZHAO Jie1 LU Wenming2.1. Research institute of Forestry Policy and Information, chinese {2. of Forestry, Beijing 100091, P. R. china 2. International Cooperation Division, chinese {2. of Forestry, Beijing 100091, P. R. china

The paper was based on the current development status of forest certification to analyze the basic characteristics of forest certification from the development point of view in terms of origin, development, main drivers and impacts, and then conducted the approach analysis to promote sustainable forest management with forest certification in china. The result showed that china shall establish her own forest certification scheme, with the focus on the improvement of forest sustainable management concept through forest certification, the promotion of forest certification through the leadership of large companies and the strengthening of capacity building. It is unrealistically expected to employ forest certification to facilitate china’s forest management immediately on the track of sustainability.

关键词： forest certification sustainable forest management approach analysis

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 fluxes and controlling factors of N_2. and CH_4 emissions from freshwater marsh in Northeast china

引用

Science china Earth Sciences 2010年第5期53卷 700-709页

作者： YU JunBao1,2. LIU JingShuang2. SUN ZhiGao1, SUN WeiDong3, WANG JinDa2. WANG GuoPing2.& CHEN XiaoBing1 1 Key Lab of Coastal Envionment Processed, Yantai institute of Coastal Zone Research for sustainable {2., chinese academy of Sciences, Yantai 2.4003, china 2.Key Lab of Wetland Ecology and environment, Northeast institute of Geography and agricultural Ecology, chinese academy of Sciences, Changchun 13.012. china 3 Key Laboratory of Isotope Geochronology and Geochemistry, Guangzhou institute of Geochemistry, chinese academy of Sciences, Guangzhou 510640, china 1. Key Lab of Coastal Envionment Processed Yantai Institute of Coastal Zone Research for Sustainable Development Chinese Academy of Sciences Yantai 264003 China2. Key Lab of Wetland Ecology and Environment Northeast Institute of Geography and Agricultural Ecology Chinese Academy of Sciences Changchun 130012 China3. Key Laboratory of Isotope Geochronology and Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China

Nitrous oxide (N2.) and methane (CH4) emissions were measured using a static chamber method in two adjacent plots of freshwater marsh predominated by Calamagrostis angustifolia, one is seasonal waterlogged (SW) and the other without surface water accumulation (NW), in Sanjiang Plain wetland (47°35′N, 13.°31′E), northeast{2., during 2.02.2.04. The diurnal and seasonal flux variations of both gases were significantly correlated with 5-cm-soil temperature. The NW marsh is a source of N2. and sink of CH4, while the SW marsh is sink of N2. and source of CH4. Remarkably, we observed a N2. emission peak under Eh of +300 to +100 mV, and CH4 emission peak under Eh of +300 to +400 mV, which indicate additional sources of N2. and CH4 for the freeze-thaw induced emission peaks of N2. and CH4 observed between late July and early August. Further study shows that the additional N2. and CH4 were emitted under the frozen soil after thawing.

关键词： freeze-thaw region freshwater marsh methane nitrous oxide controlling factors

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

sustainable AGRICULTURE development IN SALINE-ALKALI SOIL AREA OF SONGNEN PLAIN,NORTHEAST{2.

引用

chinese Geographical Science 2003年第2期13卷 171-174页

作者： WANG Zhi-chun, LI Qu-sheng, LI Xiu-jun, SONG Chang-chun, ZHANG Guang-xin (Northeast institute of Geography and agricultural Ecology, {2. academy of Sciences, Changchun 13.012. P. R. china) Northeast institute of Geography and agricultural Ecology Chinese Academy of Sciences Changchun P. R. China

There is great potential for agriculture in saline-alkali soil area in Songnen Plain, Northeast china. But the sustainable crop production in this area has been restricted by a few of main factors, such as less precipitation, h igher evaporation and frequent drought, high salinity and alkalinity, high excha ngeable sodium content and poor infiltration of the soil, and insufficiency and low availability in nutrition. It is also considered that there are a few of fav orable conditions for {2. development in this region, such as sufficien t light and heat resources, rich ground water resources, plenty of manure produc ed by livestock, and so on. At the same time, scientific management and measurem ents have been employed; rational irrigation and drainage system has been establ ished; reclamation, amendment and fertilization of soil, and suitable strategies of cropping practices have been made for the sustainable development of agricul ture. Great progress has been made during 1996-2.00.

关键词： sustainable agriculture development saline-alkali soil songnen plain

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 of tandem repeats in the genome of chinese shrimp Fenneropenaeus chinensis

引用

chinese Science Bulletin 2005年第14期50卷 1462-1469页

作者： KONG Jie1 & GAO Huan2.3 1. Key Laboratory for sustainable Utilization of Marine Fisheries Re- sources, Ministry of Agriculture, Yellow Sea Fisheris Research Insti- tute, chinese {2. of Fishery Sciences, Qingdao 2.6071, china 2. institute of Oceanology, chinese {2. of Sciences, Qingdao 2.6071, china 3. The Graduate School of the chinese {2. of Sciences, Beijing 100039, china Key Laboratory for sustainable Utilization of Marine Fisheries Resources Ministry of Agriculture Yellow Sea Fisheris Research Institute Chinese Academy of Fishery Sciences Qingdao China institute of Oceanology Chinese Academy of Sciences Qingdao China The Graduate School of the chinese academy of Sciences Beijing China

Through random sequencing, we found a total of 884000 base-pairs (bp) of random genomic sequences in the genome of chinese shrimp (Fenneropenaeus chinensis). Using bio-soft Tandem Repeat Finder (TRF) software, 2.59 tandem repeats were found, in which there were 1714 mi- crosatellites and 445 minisatellites, accounting for 79.4% and 2..6% of repeat sequences, respectively. The cumulative length of repeat sequences was found to be 116685 bp, ac- counting for 13.2. of the total DNA sequence; the cumula- tive length of microsatellites occupied 9.78% of the total DNA sequence, and that of minisatellites occupied 3.42.. In decreasing order, the 2. most abundant repeat sequence classes were as follows: AT (557), AC (471), AG (2.4), AAT (92., A (56), AAG (2.), ATC (2.), ATAG (2.), AGG (18), ACT (15), C (11), AAC (11), ACAT (11), CAGA (10), AGAA (9), AGGG (7), CAAA (7), CGCA (6), ATAA (6), AGAGAA (6). Dinucleotide repeats, not only in the aspect of the number, but also in cumulative length, were the preponderant repeat type. There were few classes and low copy numbers of repeat units of the pentanucleotide repeat type, which included only three classes: AGAGA, GAGGC and AAAGA. The classes and copy numbers of heptanucleotide, eleven-nucleotide and thirteen-nucleotide primer-number-composed repeats were distinctly less than that of repeat types beside them.

关键词：虾遗传特性遗传基因 DNA

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

Resource and environmental Quality Changes and Adjustment Principles for sustainable {2. in Rapidly Developing Coastal Region of Southeastern china

引用

Pedosphere 2001年第4期11卷 289-299页

作者： ZHAO QIGUO institute of Soil Science, the chinese {2. of Sciences, P. O. Box 82., Nanjing 2.0008 (china) 中科院南京土壤所江苏南京 210008

Problems in water-land resources and environmental quality increase with the fast economic development in the coastal region of southeastern{2.. This region has the highest density in population, industry and towns in{2., and the large export-oriented economy makes itself a strategic importance while{2. enters into international markets. The problems facing to this region include arable land reduction, land degradation aggravation, high percentage of built-up land with high rate of expansion, expanded non-point pollution, deteriorated water quality, decreasing biodiversity, destroyed ecosystems, severe air pollution, frequently occurred acid rain, and multi-pollutants. The important research fields in the near future should include a) influence of high-intensity exploitation of resources on changes of environment quality and its feedback; b) interface processes, key mechanisms and adjustment principles for degradation of water-, land-, and air-resources and environmental quality; c) evolvement processes and nurturing theory of biodiversity and ecological resources; and d) spatio-temporal variation and human-induced effects on regional resources and environment quality. Strategies for sustainable development in the region are as follows: a) controlling to ensure basic cultivated land area; b) enforcing remediation of polluted water environment, and controlling non-point pollution; c) strengthening ecological construction and ecological security; and d) controlling multi-pollution and preventing trace toxic pollutants.

关键词： coastal region environment quality fast economic development southeastern china water- land resource

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

Evaluation of sustainable Land Management and Diagnosis of Obstacle at County Scale in Sichuan Basin:Taking Lezhi County as Example

引用

Wuhan University Journal of Natural Sciences 2006年第4期11卷 1046-1051页

作者： CHEN Guangjian 1, 2. 3 , LIU Qing 1 1. Chengdu institute of Biology, chinese {2. of Sciences, Chengdu 610041, Sichuan,china 2. Graduate University of chinese {2. of Sciences, Beijing 100049, china 3. {2. of Land Reconnaissance and Layout of Sichuan Province , Chengdu 610031, Sichuan, china Chengdu institute of Biology Chinese Academy of Sciences Chengdu Sichuan China Graduate University of chinese academy of Sciences Beijing China academy of Land Reconnaissance and Layout of Sichuan Province Chengdu Sichuan China

This paper established sustainable land resources evaluating indicators fit for hilly area in Sichuan Basin, Southwest of china, and evaluated the case of sustainable land management of Lezhi County from 1990 to 2.01. The result showed that the land resource sustainable utilization ability in Lezhi County is belong to Second level （better sustainable）. Secondly, this paper diagnosed some years obstacles of sustainable land management of Lezhi County from base period to goal period and compared the obstacles factors in the indicators system. There were 16 indexes orderly become major affect factor to land sustainable utilization of Lezhi county in indicator system, of which there are 8 obstacles indexes exist both in 1990 and 2.01. The value of obstacles degree of five indicators exceeded 5 in 1990, but in 2.01, only two indicators＇ values were more than 5.

关键词： land resources sustainable land management assessment indicators diagnosis of obstacle

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

Temporal and spatial variations of δ^(15)N and δ^(18)O for atmospheric N_2. above the oceanic surface from Shanghai to Antarctica

引用

Science china Earth Sciences 2008年第6期51卷 899-910页

作者： ZHU RenBin1, LIU YaShu1, XU Hua2. MA Jing2.& SUN LiGuang1 1 institute of Polar environment, University of Science and Technology of{2., Hefei 2.002.,{2. 2.State Key Laboratory of Soil and sustainable Agriculture, institute of Soil Science, chinese academy of Sciences, Nanjing 2.0091,{2. 1. institute of Polar environment University of Science and Technology of China Hefei 230026 China 2. State Key Laboratory of Soil and sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210091 China

During the 2.nd chinese Antarctic Research Expedition (chinaRE-2.), the atmospheric gas samples above the oceanic surface and near the surface were collected on the track for the scientific ship "Xuelong" and on Millor Peninsula of eastern Antarctica, respectively, using the Tedlar gas bags. Every day the sampling times were 10:00 and 2.:00 (local time), respectively. In the laboratory, high-precision measurement of the isotopic compositions for N2. in these gas samples was conducted using Thermo Finnigan MAT-2.3 Isotopic Mass Spectrometer with a fully automated interface for the pre-GC concen-tration (PreCon) of trace gases. The temporal and spatial variations of δ 15N and δ 18O in atmospheric N2. were analyzed. The mean δ 15N and δ 18O-N2. values above the oceanic surface were (7.2.±0.50)‰ and (44.52.0.52.‰, respectively. From 30°N to Antarctica, the δ 15N (6.05‰―7.88‰) linearly increased with the rate of about 0.01‰ with the latitude while the δ 18O (43.05‰―48.78‰) showed a large fluctua-tion. The δ 15N negatively correlated with air temperature and N2. concentration, and slightly positively correlated with δ 18O. The summertime variations of δ 15N and δ 18O-N2. appeared the same trend on Millor Peninsula of eastern Antarctica. They significantly positively correlated with each other and negatively with N2. concentration. The δ 15N and δ 18O-N2. at different sites averaged (7.42.0.35)‰ and (44.69±0.49)‰, respectively, slightly higher than those above the oceanic surface, significantly higher than those of atmospheric N2. in the low-latitude regions of Northern Hemisphere. The predominant factors affecting the spatial variations of δ 15N and δ 18O values were also discussed. The isotopic data given in this study can help to investigate the global and regional N2. budgets.

关键词： nitrous oxide Antarctica atmosphere δ^(15)N δ^(18)O isotope ocean

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

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：