检索结果-南通市图书馆

Soil Aggregate Stability and Aggregate-Associated Carbon Under Different Tillage Systems in the North China Plain

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2013年第11期12卷 2114-2123页

作者： DU Zhang-liu REN Tu-sheng HU Chun-sheng ZHANG Qing-zhong Humberto Blanco-Canqui institute of environment and Sustainable development in Agriculture Chinese Academy of Agricultural Sciences College of resources and environmental Sciences China Agricultural University center for Agricultural resources research Institute of Genetics and Development BiologyChinese Academy of Sciences Agricultural research center-Hays Kansas State University

The inlfuences of tillage systems on soil carbon （C） stocks have been studied extensively, but the distribution of soil C within aggregate fractions is not well understood. The objective of this study was to determine the inlfuences of various tillage systems on soil aggregation and aggregate-associated C under wheat （Triticum aestivum L.） and corn （Zea mays L.） double cropping systems in the North China Plain. The experiment was established in 2001, including four treatments：moldboard plow （MP） with residue （MP＋R） and without residue （MP-R）, rotary tillage with residue （RT）, and no-till with residue （NT）. In 2007 soil samples were collected from the 0-5, 5-10, and 10-20 cm depths, and were separated into four aggregate-size classes （〉2 000, 250-2 000, 53-250, and〈53 μm） by wet-sieving method. Aggregate-associated C was determined, and the relationships between total soil C concentration and aggregation-size fractions were examined. The results showed that NT and RT treatments signiifcantly increased the proportion of macroaggregate fractions （〉2 000 and 250-2 000 μm） compared with the MP-R and MP＋R treatments. Averaged across all depths, mean weight diameters of aggregates （MWD） in NT and RT were 47 and 20% higher than that in MP＋R. The concentration of bulk soil organic C was positively correlated with MWD （r=0.98; P=0.024） and macroaggregate fraction （r=0.96; P=0.036） in the 0-5 cm depth. In the 0-20 cm depth, comparing with MP＋R, total C occluded in the〉2 000 μm fraction was increased by 9 and 6%under NT and RT, respectively. We conclude that adoption of conservation tillage system, especially no-till, can increase soil macro-aggregation and total C accumulation in macroaggregates, which may improve soil C sequestration in the intensive agricultural region of the North China Plain.

关键词： tillage systems aggregate stability aggregate-associated C

Infrastructure Finance under the Framework of the Belt and Road Initiative (BRI)

在线全文

学校读者我要写书评

暂无评论

China Finance and Economic Review 2018年第2期7卷 35-47页

作者： Liping Zhang research institute for development research center of the state council of China(DRC)

Infrastructure connectivity is one of the cooperation priorities of the Belt and Road Initiative(BRI).The construction and improvement of infrastructure means a large amount of investment as well as lots of *** study tries to gauge the funding needs for the countries along the Belt and Road for infrastructure investment to maintain a relatively rapid economic *** make it convenient for analysis,this study only projects the appropriate infrastructure investment demand of 65 countries along the Belt and Road that have relatively complete GDP statistics in recent *** the projection result is the total appropriate infrastructure investment demand is expected to be about US$11.5 trillion between 2017 and *** overcome the challenges and attract more funds to meet the large-scale infrastructure investment demand of the BRI countries,it is critical to improve the infrastructure investment environment in the *** governments’functions of improving investment environment,the role of private investors is of equal importance as market rules and international norms are followed in the process of facilities connectivity construction of the BRI.

关键词： the Belt and Road Initiative(BRI) facilities connectivity infrastructure finance

Carbon and nitrogen allocations in corn grown in Central and Northeast China: different responses to fertilization treatments

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

Journal of Integrative Agriculture 2015年第6期14卷 1212-1221页

作者： MIAO Hui-tian Lü Jia-long XU Ming-gang ZHANG Wen-ju HUANG Shao-min PENG Chang CHEN Li-ming College of Natural resources and environment Northwest A&F University Key Laboratory of Crop Nutrition and Fertilization Ministry of Agriculture/Institute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural Sciences institute of Plant Nutrition and environmental resources Science Henan Academy of Agricultural Sciences Agricultural resources and environment research center Jilin Academy of Agricultural Sciences School of environment and Natural resources The Ohio State University/The Ohio Agricultural Research and Development Center

In order to reveal the impact of various fertilization strategies on carbon（C） and nitrogen（N） accumulation and allocation in corn（Zea mays L.）, corn was grown in the fields where continuous fertilization management had been lasted about 18 years at two sites located in Central and Northeast China（Zhengzhou and Gongzhuling）, and biomass C and N contents in different organs of corn at harvest were analyzed. The fertilization treatments included non-fertilizer（control）, chemical fertilizers of either nitrogen（N）, or nitrogen and phosphorus（NP）, or phosphorus and potassium（PK）, or nitrogen, phosphorus and potassium（NPK）, NPK plus manure（NPKM）, 150% of the NPKM（1.5NPKM）, and NPK plus straw（NPKS）. The results showed that accumulated C in aboveground ranged from 2 550–5 630 kg ha^–1 in the control treatment to 9 300–9 610 kg ha^–1 in the NPKM treatment, of which 57–67% and 43–50% were allocated in the non-grain organs, respectively. Accumulated N in aboveground ranged from 44.8–55.2 kg ha^-1 in the control treatment to 211–222 kg ha^–1 in the NPKM treatment, of which 35–48% and 33–44% were allocated in the non-grain parts, respectively. C allocated to stem and leaf for the PK treatment was 65 and 49% higher than that for the NPKM treatment at the both sites, respectively, while N allocated to the organs for the PK treatment was 18 and 6% higher than that for the NPKM treatment, respectively. This study demonstrated that responses of C and N allocation in corn to fertilization strategies were different, and C allocation was more sensitive to fertilization treatments than N allocation in the area.

关键词： fertilization allocation Northeast phosphorus fertilizers potassium organs ranged accumulated allocated

Long-term organic and inorganic fertilizations enhanced basic soil productivity in a fluvo-aquic soil

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2015年第12期14卷 2477-2489页

作者： ZHA Yan WU Xue-ping GONG Fu-fei XU Ming-gang ZHANG Hui-min CHEN Li-ming HUANG Shao-min CAI Dian-xiong National Engineering Laboratory for Improving Quality of Arable Land Institute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural Sciences School of environment and Natural resources The Ohio State UniversityOhio Agricultural Research and Development Center institute of Plant Nutrition Resources and Environment Henan Academy of Agricultural Sciences

The improvement of soil productivity depends on a rational input of water and nutrients, optimal field management, and the increase of basic soil productivity（BSP）. In this study, BSP is defined as the productive capacity of a farmland soil with its own physical and chemical properties for a specific crop season under local field management. Based on 19-yr data of the long-term agronomic experiments（1989–2008） on a fluvo-aquic soil in Zhengzhou, Henan Province, China, the decision support system for agrotechnology transfer（DSSAT ver. 4.0） crop growth model was used to simulate yields by BSP of winter wheat（Triticum aestivium L.） and summer maize（Zea mays L.） to examine the relationship between BSP and soil organic carbon（SOC） under long-term fertilization. Five treatments were included：（1） no fertilization（control）,（2） nitrogen, phosphorus and potassium fertilizers（NPK）,（3） NPK plus manure（NPKM）,（4） 1.5 times of NPKM（1.5NPKM）, and（5） NPK plus straw（NPKS）. After 19 yr of treatments, the SOC stock increased 16.7, 44.2, 69.9, and 25.2% under the NPK, NPKM, 1.5NPKM, and NPKS, respectively, compared to the initial value. Among various nutrient factors affecting contribution percentage of BSP to winter wheat and summer maize, SOC was a major affecting factor for BSP in the fluvo-aquic soil. There were significant positive correlations between SOC stock and yields by BSP of winter wheat and summer maize（P〈0.01）, and yields by BSP of winter wheat and summer maize increased 154 and 132 kg ha^（–1） when SOC stock increased 1 t C ha^（–1）. Thus, increased SOC accumulation is a crucial way for increasing BSP in fluvo-aquic soil. The manure or straw combined application with chemical fertilizers significantly enhanced BSP compared to the application of chemical fertilizers alone.

关键词： soil organic carbon basic soil productivity long-term fertilization DSSAT model fluvo-aquic soil wheat-maize rotation

Review and adjustment of China’s opening strategy

在线全文

学校读者我要写书评

暂无评论

China Finance and Economic Review 2014年第1期3卷 54-69页

作者： Long Guoqiang development research center for the state council China

In the past 30 years,by targeting the use of external resources and market industrialization as the strategic goals of opening to the outside world and seizing the opportunities first provided by the cross-border transfer of labor-intensive industries in East Asia and then from the external market,China has given full play to its advantages of low manufacturing costs and has achieved remarkable *** present,as profound changes have been ongoing in terms of China’s comparative advantage from its participation in the global division of labor,the transformation of its development model is ***,the changing international economic environment also provides China with favorable opportunities through which more advanced production factors and industries can be introduced and global resources be integrated with the enforcement of the“going out”*** such a new period,China should set a target of enhancing its global production value chain and unswervingly implement the opening strategy for mutual benefit and win-win *** striving to create a favorable external economic environment,further promoting trade and investment liberalization and boosting the upgrading of the industrial structure and export structure,China’s soft power and participation competency in global governance will be improved.

关键词： opening strategy industrial structural upgrading global value chain

Climate Change and Green Growth:A Perspective of the Division of Labor

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

China & World Economy 2014年第5期22卷 93-116页

作者： Yongsheng Zhang development research center of the state council of China

This paper presents a new research agenda on climate change and green growth from the perspective of the division of labor in classical economics. The paper covers three major dimensions of green growth （i.e. carbon emissions, environmental proteetion and material resources use） and some related important topics, as well as the fresh policy implications of the new research agenda, Typical marginal analysis in a given structure of the division of labor suggests that ＂green＂ action is a burden to economic development. Therefore, climate negotiation has become a burden-sharing game and has reached a stalemate. New thinking is badly needed to rescue these negotiations and to drive a shift to a new ＂green growth＂ paradigm. The proposed new research agenda represents an effort to create a new narrative on climate change and green growth. Because the new research agenda can theoretically predict the possibility that a more competitive structure of the division of labor could be triggered by ＂＇green ＂＇ policy, it has promising policy implications for various important challenges facing us in the 21st century.

关键词： climate change division of labor green growth specialization

Hydropower reservoirs on the upper Mekong River modify nutrient bioavailability downstream

在线全文

学校读者我要写书评

暂无评论

National Science Review 2020年第9期7卷 1449-1457页

作者： Qiuwen Chen Wenqing Shi Jef Huisman Stephen C.Maberly Jianyun Zhang Juhua Yu Yuchen Chen Daniele Tonina Qitao Yi state Key Laboratory of Hydrology-Water resources & Hydraulic Engineering Nanjing Hydraulic Research Institute center for Eco-environment research Nanjing Hydraulic Research Institute Department of Freshwater and Marine Ecology Institute for Biodiversity and Ecosystem DynamicsUniversity of Amsterdam Lake Ecosystems Group UK Centre for Ecology & Hydrology 5. Department of Eco-Environment Conservation Yangtze Institute for Conservation and Development 6. Center for Ecohydraulics Research University of Idaho

Hydropower development is the key strategy in many developing countries for energy supply,climate-change mitigation and economic development. However, it is commonly assumed that river dams retain nutrients and therefore reduce downstream primary productivity and fishery catches, compromising food security and causing trans-boundary disputes. Contrary to expectation, here we found that a cascade of reservoirs along the upper Mekong River increased downstream bioavailability of nitrogen and *** dams caused phytoplankton density to increase with hydraulic residence time and stratification of the stagnant reservoirs caused hypoxia at depth. This allowed the release of bioavailable phosphorus from the sediment and an increase in dissolved inorganic nitrogen as well as a shift in nitrogen species from nitrate to ammonium, which were transported downstream by the discharge of water from the base of the dam. Our findings provide a new perspective on the environmental impacts of river dams on nutrient cycling and ecosystem functioning, with potential implications for sustainable development of hydropower worldwide.

关键词： Mekong River cascade reservoirs downstream nutrient bioavailability nitrogen phosphorus

Spatiotemporal evolution and driving factors of China's flash flood disasters since 1949

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Earth Sciences 2018年第12期61卷 1804-1817页

作者： Yesen LIU Zhenshan YANG Yaohuan HUANG Changjun LIU China institute of Water resources and Hydropower research Research Center on Flood & Drought Disaster Reduction of the Ministry of Water Resources Key Lab of Regional Sustainable development and Modelling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences state Key Laboratory of resources and environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences

This study examines the spatiotemporal evolution of China's flash flood disasters(FFDs) since 1949 and explores driving factors affecting the spatial distribution of historical FFDs. Records of more than 60000 FFDs are examined, and the centroid comparison method is used to reveal the spatiotemporal evolution of FFDs from 1951 to 2015. In particular, the geographical locations of the centroids, degrees of aggregation, and associated movement tendencies are examined to conduct a preliminary analysis of correlations between rainfall, population, and the spatiotemporal evolution of FFDs. Subsequently, using relevant data from 2000 to 2015, three factors relating to FFDs in natural watershed units include namely rainfall, human activity,and the environment of the Earth's surface. The geographical detector method is then employed to explore the effect of these driving factors on the spatial distribution of FFDs. Analysis results show that displacement of the spatial distribution of FFDs since 1949 is correlated with variations in rainfall and population distribution. In addition, it is determined that the distribution of FFDs occurring between 2000 and 2015 have regional differentiation characteristics. However, the effect of rainfall on the distribution of FFDs is more significant than that of human activity or the environment of the Earth's surface, but interactions occur between these latter two factors in disaster-formative environments. Furthermore, results also show that the driving factors of FFDs have significant spatiotemporal heterogeneity. In China, regions at high risk of FFDs include the Sichuan-Chongqing ecological zone, the South China ecological zone, the Yunnan-Guizhou Plateau, and the middle and lower reaches of the Yangtze River, while regions with a low risk of FFDs include the Northwest China arid zone, Qinghai-Tibet Plateau, Inner Mongolian Plateau, and the Northeast China ecological zone. These findings support further studies investigating disaste

关键词： Flash flood disaster Centroid Driving factor Human activity Rainfall

Comparision of China's volatile organic compound pollution management:a computable general equilibrium approach

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Population,resources and environment 2016年第4期16卷 298-308页

作者： Yufei Wang Changxin Liu Tong Wu Zhengping Hao Zheng Wang Management World Development Research Center of the State Council

The public health and ecological impacts of volatile organic compound(VOCs) pollution have become a serious problem in China,arousing increasing attention to emissions *** this context,this paper analyses the effectiveness of VOC reduction policies,namely pollution charges and environmental taxes at the national and industrial sector *** uses a computable general equilibrium model,which connects macroeconomic variables with VOC emissions inventory,to simulate the effects of policy scenarios(with 2007 as the reference year).This paper shows that VOC emissions are reduced by 2.2% when a pollution charge equal to the average cost of engineering reduction methods-the traditional approach to regulation in China-is *** order to achieve a similar reduction,an 8.9% indirect tax would have to be *** concludes that an environmental tax should be the preferred method of VOC regulation due to its smaller footprint on the *** policies,such as subsidies,should be used as supplements.

关键词： Volatile organic compounds environmental tax pollution charge computable general equilibrium models