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Estimation methods of eco-environmental water requirements: Case study

Science China Earth Sciences 2005年第8期48卷 1280-1292页

作者： YANG Zhifeng1,2, CUI Baoshan1 & LIU Jingling 1. School of Environment, Beijing Normal University, Beijing 100875, China 2. State Key Joint Laboratory of Environmental Simulation and Pollution Control, Beijing 100875, China 1. School of Environment Beijing Normal University 100875 Beijing China 2. State Key Joint Laboratory of Environmental Simulation and Pollution Control 100875 Beijing China

Supplying water to the ecological environment with certain quantity and quality is significant for the protection of diversity and the realization of sustainable development. The conception and connotation of eco-environmental water requirements, including the definition of the conception, the composition and characteristics of eco-environmental water requirements, are evaluated in this paper. The classification and estimation methods of eco-environmental water requirements are then proposed. On the basis of the study on the Huang-Huai-Hai Area, the present water use, the minimum and suitable water requirement are estimated and the cor-responding water shortage is also calculated. According to the interrelated programs, the eco-environmental water requirements in the coming years (2010, 2030, 2050) are estimated. The result indicates that the minimum and suitable eco-environmental water requirements fluc-tuate with the differences of function setting and the referential standard of water resources, and so as the water shortage. Moreover, the study indicates that the minimum eco-environmental water requirement of the study area ranges from 2.84×1010m3 to 1.02×1011m3, the suitable water requirement ranges from 6.45×1010m3 to 1.78×1011m3, the water shortage ranges from 9.1×109m3 to 2.16×1010m3 under the minimum water requirement, and it is from 3.07×1010m3 to 7.53×1010m3 under the suitable water requirement. According to the different values of the water shortage, the water priority can be allocated. The ranges of the eco-environmental water re-quirements in the three coming years (2010, 2030, 2050) are 4.49×1010m3?1.73×1011m3, 5.99×10m3?2.09×1011m3, and 7.44×1010m3?2.52×1011m3, respectively.

关键词： eco-environmental water requirements, assessment methods, Huang-Huai-Hai area.

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Monotone projected gradient methods for large-scale box-constrained quadratic programming

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Science China Mathematics 2006年第5期49卷 688-702页

作者： ZHOU Bin, GAO Li & DAI Yuhong School of Mathematical Sciences and LMAM, Peking University, Beijing 100871, China State Key Laboratory of Scientific and Engineering Computing, Institute of Computational Mathematics and Scientific/Engineering Computing, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing 100080, China School of Mathematical Sciences LMAM Peking University Beijing 100871 China State Key Laboratory of Scientific Engineering Computing Institute of Computational Mathematics Scientific/Engineering Computing Academy of Mathematics Systems Science Chinese Academy of Sciences Beijing 100080 China

Inspired by the success of the projected Barzilai-Borwein (PBB) method for largescale box-constrained quadratic programming, we propose and analyze the monotone projected gradient methods in this paper. We show by experiments and analyses that for the new methods,it is generally a bad option to compute steplengths based on the negative gradients. Thus in our algorithms, some continuous or discontinuous projected gradients are used instead to compute the steplengths. Numerical experiments on a wide variety of test problems are presented, indicating that the new methods usually outperform the PBB method.

关键词： projected gradients, monotone gradient methods, box-constrained quadratic programming, large-scale problems.

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B-Theory of Runge-Kutta methods for stiff Volterra functional differential equations

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Science China Mathematics 2003年第5期46卷 662-674页

作者：李寿佛 Department of Mathematics Xiangtan University Xiangtan 411105 China

B-stability and B-convergence theories of Runge-Kutta methods for nonlinear stiff Volterra func-tional differential equations (VFDEs) are established which provide unified theoretical foundation for the studyof Runge-Kutta methods when applied to nonlinear stiff initial value problems (IVPs) in ordinary differentialequations (ODEs), delay differential equations (DDEs), integro-differential equations (IDEs) and VFDEs ofother type which appear in practice.

关键词： stiff functional differential equations, Runge-Kutta methods, B-stability, B-con-vergence.

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Efficient parallel multivalue hybrid methods for stiff differential equations

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Science China Mathematics 2002年第10期45卷 1276-1290页

作者：李寿佛 1. Department of Mathematics Xiangtan University 411105 Xiangtan China

A class of efficient parallel multivalue hybrid methods for stiff differential equations are presented,which are all extremely stable at infinity, A-stable for orders 1-3 and A(α)-stable for orders 4-8. Eachmethod of the class can be performed parallelly using two processors with each processor having almost thesame computational amount per integration step as a backward differentiation formula (BDF) of the same orderwith the same stepsize performed in serial, whereas the former has not only much better stability propertiesbut also a computational accuracy higher than the corresponding BDF. Theoretical analysis and numericalexperiments show that the methods constructed in this paper are superior in many respects not only to BDFsbut also to some other commonly used methods.

关键词： stiff differential equations, general multivalue methods, parallel computation.

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ON THE BREAKDOWNS OF THE GALERKIN AND LEAST-SQUARES methods

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Numerical Mathematics A Journal of Chinese Universities(English Series) 2002年第2期11卷 137-148页

作者： Zhong Baojiang(钟宝江) College of Science Nanjing University of Aero. & Astro. Nanjing 210016 PRC

The Galerkin and least-squares methods are two classes of the most popular Krylov subspace methods for solving large linear systems of equations. Unfortunately, both the methods may suffer from serious breakdowns of the same type: In a breakdown situation the Galerkin method is unable to calculate an approximate solution, while the least-squares method, although does not really break down, is unsucessful in reducing the norm of its residual. In this paper we first establish a unified theorem which gives a relationship between breakdowns in the two methods. We further illustrate theoretically and experimentally that if the coefficient matrix of a lienar system is of high defectiveness with the associated eigenvalues less than 1, then the restarted Galerkin and least-squares methods will be in great risks of complete breakdowns. It appears that our findings may help to understand phenomena observed practically and to derive treatments for breakdowns of this type.

关键词： large linear systems, iterative methods, Krylov subspace methods, Galerkin method, least-squares method, FOM , GMRES , breakdown, stagnation, restarting, preconditioners.

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Convergence of one-leg methods for singular perturbation problems with delays

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Science China Mathematics 2002年第3期45卷 280-289页

作者：甘四清孙耿 1. Department of Computer Science and Technology Tsinghua University 100084 Beijing China 2. Institute of Mathematics Chinese Academy of Sciences 100080 Beijing China

This paper is concerned with the error behaviour of one-leg methods applied to some classes of one-parameter multiple stiff singularly perturbed problems with delays. We obtain convergence results of A-stable one-leg ... 详细信息

关键词： singular perturbation problems with delays, interpolation, one-leg methods, convergence.

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Effect of Planting Date, Spacing and Seeding methods on Disease Development and Yield Components of Rice （Oryza sativa L.） in Southeastern Nigeria

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Journal of Agricultural Science and Technology(B) 2017年第2期7卷 100-113页

作者： Christian Chukwunenye Iwuagwu Charles Ikechukwu Umechuruba Andrew Chukwuma Nwogbaga Department of Crop Science and Horticulture Nnamdi Azikiwe University PMB 5025 Awka Anambra State Nigeria Evangel University PMB 129 Abakaliki Ebonyi State Nigeria Department of Crop Production and Landscape Management Ebonyi State University PMB 053 Abakaliki Nigeria

To investigate the effect of planting date, spacing and seeding methods on disease development and yield components ofrice, a factorial experiment in randomized complete block design （RCBD） with four replications was conducted during 2011 plantingseason at Izzi Local Government Area （LGA） of Ebonyi State, Nigeria. This experiment was carried out with four levels of plantingdates （early June, late June, early July and late July）, three levels of spacing （15, 20 and 25 cm） and two levels of seeding method（direct seeding and seedling transplanting）. The studied traits included plant height （PH）, number of tillers （NT）, leaf area （LA）, rootlength （RL）, panicle length （PL）, 1,000 seed weight （SW）, disease incidence and severity. The result showed that all the factors hadsignificant effect on the parameters measured. Sowing in early July had the highest LA of 65.38 cm^2, PH of 122.00 cm, RL of 29.04cm and TN of 10.54, and the second largest PL of 25.08 cm and SW of 25.12 g. Also sowing in early July had the highest diseaseseverity of 3.21, followed by 3.14 which occurred in late July, while the least 2.17 occurred in early June. The direct seeding methodhad the highest disease incidence of 70.83%, followed by plant spacing of 15 cm × 15 cm which had the disease incidence of 69.72%,while sowing in early June had the least disease incidence of 57.50%. In conclusion, planting of rice in Southeastern Nigeria shouldbe done in early July, as the yield components were significantly better than in other dates though with the highest disease severity.

关键词： Disease development, planting dates, spacing, planting methods, rice, Southeastern Nigeria, yield components.

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Naming methods and intention research in English novels

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International Journal of Technology Management 2015年第8期 7-8页

作者： Li Ziyao NORTH CHINA ELECTRIC POWER UNIVERSITY BEIJING102206

Names are unique phenomenon in human society. People from different countries all have their only names, which generally consist of the first name and the last name. Not only in reality, but also in literary works, they all have their unique names, but the naming methods and intention are different. This paper emphasizes the naming methods and intention in English novels. The names of English novels usually have a richer culture, it embodies the character traits and characters in the novel, such as the outcome of their fate. Therefore, the research of the cultural intention of English novels and translating names accurately is of great significance for literary translation, which also plays an important role in the East-West cultural exchange.

关键词： English novels, Naming methods, Intention

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Clinical Value of Molecular Biological methods in Respiratory Tuberculosis in Children

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Journal of Health Science 2014年第5期2卷 248-251页

作者： Ulia Ovchinnikova Anna Starshinova Irina Dovgalyuk Natalia Kornev Viacheslav Zhuravlev Department of Phthisiopulmonology St. Petersburg Research Institute of Phthisiopulmonology Ligovskii pr. 2/4 St. Petersburg191036 Russian Federation

The pattern of clinical forms of respiratory tuberculosis in children shows a preponderance of intrathoracic lymph node tuberculosis （89.4%） that is characterized by a complicated process in every third child under present-day conditions. Positive result of PCR closely correlates with the severity and extent of the specific process in children. Real-time PCR （RT-PCR） was ascertain to exhibit the highest sensitivity in detecting Mycobacterium tuberculosis DNA in children with primary generalized tuberculosis （62.5%） and in those with a disseminated specific process （55.6%）, which was much higher than conventional bacteriological study of diagnostic materials. By taking into account the findings, the RT-PCR detection of M. tuberculosis was considered as a substantial criterion for evaluating the magnitude of specific changes and the degree of tuberculosis infection activity in children.

关键词： Molecular biological methods, real-time polymerase chain reaction, respiratory tuberculosis, children.

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Variational Analysis of Toda Systems(To Ham with admiration and gratitude)

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Chinese Annals of Mathematics,Series B 2017年第2期38卷 539-562页

作者： andrea malchiodi Scuola Normale Superiore Piazza dei Cavalieri 750126 PisaItaly

The author surveys some recent progress on the Toda system on a twodimensional surface Σ, arising in models from self-dual non-abelian Chern-Simons vortices,as well as in differential geometry. In particular, its variational structure is analysed, and the role of the topological join of the barycentric sets of Σ is shown.

关键词： Geometric PDEs, Variational methods, Min-max schemes

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