检索结果-南通市图书馆

Relationship Between Microbial Community and Soil Properties During Natural Succession of Abandoned Agricultural Land

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2010年第3期20卷 352-360页

作者： JIA Guo-Mei ZHANG Pei-Dong WANG Gang CAO Jing HAN Jing-Cheng HUANG Ying-Ping College of Chemistry and Life Science China Three Gorges Unversity Yichang 443002 (China) Key Laboratory of Arid and Grassland Ecology School of Life Science Lanzhou University Lanzhou 730000 (China) Qingdao Institute of Bioenergy and Bioprocess Technology Chinese Academy of Sciences Qingdao 266071 (China)

The changes of microbial biomass carbon (MBC) and nitrogen (MBN) and microbial community in the topsoil of the abandoned agricultural land on the semi-arid Loess Plateau in China during the natural succession were evaluated to understand the relationship between microbial community and soil properties. MBC and MBN were measured using fumigation extraction, and microbial community was analyzed by the method of fatty acid methyl ester (FAME). The contents of organic C, total N, MBC, MBN, total FAME, fungal FAME, bacterial FAME and Gram-negative bacterial FAME at the natural succession sites were higher than those of the agricultural land, but lower than those of the natural vegetation sites. The MBC, MBN and total FAME were closely correlated with organic C and total N. Furthermore, organic C and total N were found to be positively correlated with fungal FAME, bacterial FAME, fungal/bacterial and Gram-negative bacterial FAME. Natural succession would be useful for improving soil microbial properties and might be an important alternative for sustaining soil quality on the semi-arid Loess Plateau in China.

关键词： fatty acid methyl ester microbial biomass soil carbon soil nitrogen

Test Studies on Performances of TGP Total Gradation Concrete

在线全文

学校读者我要写书评

暂无评论

Engineering Sciences 2005年第4期 32-38页

作者： Dai Huichao~(1,2)(1. Hohai University, Nanjing 210098 2. China Yangtze three gorges Project Development corporation, {3., 443.02.

The three gorges Project （TGP） is the largest water conservancy and hydropower complex in the world, with a concrete consumption of 28 million m3.n total. For such a significant world-attracting project, first rate quality concrete is needed. Various mechanical and deformation performances of hydraulic mass concrete are determined conventionally by the wet screening method to make small specimens and the test results of the small standard specimens are taken to represent the properties of the mass concrete. However, the quantity of the coarse aggregate after wet screening would be reduced by 3.% or so and the gel materials would increase by 20% or so, thus causing significant differences between the properties of the small concrete specimen and that of the total gradation concrete. To well understand the performances of the total gradation concrete of TGP dam, test studies have been performed on the total gradation concrete, including compressive strength, split tensile strength, elastic modulus, ultimate tension, dry shrinkage, self volume deformation, creep, seepage prevention, and so on, and comparison made with the small standard specimens to find out the relationship between them, which have provided scientific ground for the design, operation and safety verification of the TGP dam.

关键词： three gorges Project hydraulic mass concrete total gradation concrete performance tests

Composite Disturbance-observer-based Control and H∞ Control for Time-delay Systems with Nonlinear Perturbations

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Composite Disturbance-observer-based Control and H∞ Control...

第二十九届中国控制会议

作者： YAN Peng1,SHEN Yanjun,JIAO Jian3..College of Science,China three gorges University,yichang Hubei {3.P.R.China2.College of Science,China three gorges University,yichang Hubei {3.P.R.China3.Electrical Engineering&Renewable Energy School,China three gorges University,yichang Hubei {3.P.R.China

This paper considers the problem of composite disturbance-observer-based control（DOBC） and H∞ control for time-delay systems with nonlinear *** external disturbance is supposed to be generated by an exogenous system withtime *** designing the corresponding disturbance observer and controller,we obtain a complex closed-loop *** on the LMI technologies and Lyapunov stability theory,we ensure the asymptotical stability and a prescribed H∞ level of the obtained closed-loop system,which means the disturbance rejection and guarantees asymptotical stability anda prescribed H∞ level of the considered time-delay system with nonlinear ***,simulation illustrates the effectiveness of the proposed methods.

关键词： DOBC H∞Control Time-delay System Nonlinear Perturbation LMI

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

过水围堰初期导流工期风险率计算模型

水电能源科学 1996年第3期14卷 176-182页

作者：孙志禹中国长江三峡工程开发总公司

针对过水围堰初期导流围堰使用期内有效施工工期的随机特性分析，结合水电工程建设实际，提出了工期风险率的概念，并给出了研究工期风险率的计算模型．

关键词：围堰导流工期风险率

基于AR(m)-QAR-GARCH模型的沪深指数VaR测度研究

在线全文

学校读者我要写书评

暂无评论

重庆三峡学院学报 2018年第4期34卷 42-53页

作者：奚晓军王淼晗章贵军闽南师范大学商学院福建漳州363000 上海德勤税务事务所有限公司北京分所北京100738 江西财经大学统计学院江西南昌330013

传统的GARCH模型在测度我国沪深指数日对数收益率VaR时,由于不能兼顾其尖峰、厚尾、有偏性和自相关性的特征往往效果不佳。针对沪深指数日对数收益率的上述特点,提出利用AR(m)-QAR-GARCH模型测度我国三大股指的VaR。基于Kupiec似然比和D... 详细信息

传统的GARCH模型在测度我国沪深指数日对数收益率VaR时,由于不能兼顾其尖峰、厚尾、有偏性和自相关性的特征往往效果不佳。针对沪深指数日对数收益率的上述特点,提出利用AR(m)-QAR-GARCH模型测度我国三大股指的VaR。基于Kupiec似然比和DQ检验表明:AR(m)-QAR-GARCH模型测度沪深指数VaR预测准确性要好于自相关性不明显的恒生指数和日经指数;AR(m)-QAR-GARCH模型对沪深指数VaR测度效果要好于几种没有考虑自相关性的GARCH模型;对于我国沪深指数收益率自相关性可能存在的阶段性特点,AR(m)-QAR-GARCH模型也适合。

关键词： VaR 自相关性 GARCH Kupiec检验 DQ检验

Decision Support System for Emergency Response of Geological Hazards in three gorges Reservoir Area

在线全文

学校读者我要写书评

暂无评论

Decision Support System for Emergency Response of Geological...

Construction of the DNA vaccine of HPV18E7 combinding SLC in eucaryotic expression vector

2010 Second International Seminar On Business and Information Management (ISBIM 2010)

作者： Haifeng HUANG College of Civil Engineering and Architecture China three gorges University yichang China Shimei WANG College of Civil Engineering and Architecture China three gorges University yichang China

China three gorges reservoir area（TGRA） has always been severe geological hazards,and it gets worse when reservoir water level rises greatly with the construction of dam,emergency response of geo-hazards is becoming a frequent and important *** guarantee the order and high efficacy,it is necessary to establish decision support system to assist the decision makers to work out perfect emergency response *** to years of experience in TGRA,on the basis of summarizing emergency response framework that included emergency survey,risk assessment and emergency decision-making,a decision support system for emergency response of geo-hazards in TGRA,which consisted of database,model base,knowledge base,case base and inference machine was established,and three decision-making processes included emergency preplan decision-making,emergency plan decision-making and emergency measures decision-making were *** application effect indicated the DSS system had good practicability because it could not only meet the multi-level and multi-task requirement of geo-hazards emergency response decision-making,but also tally with the practical scenarios.

关键词： decision support system emergency response geological hazards three gorges reservoir area

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

Construction of the DNA vaccine of HPV18E7 combinding SLC in...

Application Research for the Grid Technology

湖北省暨武汉市生物化学与分子生物学学会第八届第十七次学术年会

作者： ZHU Ping~1 Zen fanhui~1 ZHANG changju~1 1 Keystone laboratory of Immunology of China three gorges University medical college 2 Institute of Molecular Biology of China three gorges University 3.Department of gynaecology and obstetrics of Renhe Hospital of China three gorges University,

Objective:In order to achieve the DNA vaccine of HPV18 related tumor and infected diseases, we construct the eukaryotic expression plasmid carrying HPV18E7 combinding murine SLC full length gene.

关键词： human papilloma virus Secondary lymphoid tissue chemokine Eukaryotic expression DNA vaccine

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

微计算机信息 2007年第3期23卷 159-161页

作者： (Chongqing three gorges College, Chongqing Wanzhou, 404000, China)Xu bing Chongqing three gorges College Chongqing Wanzhou 404000

It introduces the basic concept of grid, its definition, characters and computing. The new research of grid architecture and its application are also introduced.

关键词： grid computing of grid architecture application of grid.

Review on Commissioning Test of three gorges Power Transmission & Substation Project

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Electricity 2009年第2期20卷 33-38页

作者： Yang Wankai1,Yin Yonghua1,Zeng Nanchao1,Wang Minxin1,Chong Zhiyi2,Ma Weimin2,Kang Jian3.1. China Electric Power Research Institute 2. State Grid Direct Current Project Construction Company Limited 3. Hubei Electric Power Test Research Institute Yang Xiaoli China Electric Power Research Institute State Grid Direct Current Project Construction Company Limited Hubei Electric Power Test Research Institute

Holding the greatest power transmission capacity in China, three gorges power transmission and substation (T&S) project is an important landmark in the

关键词： AC DC test Review on Commissioning Test of three gorges Power Transmission Substation Project Test