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A TEST FOR SPHERICITY OF ERRORS IN LINEAR MODELS

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Systems Science and Mathematical sciences 1997年第3期10卷 202-207页

作者： WANG Songgui(Institute of Statistics, beijing Polytechnic University, beijing 10002.,{2.)(Institute of applied of mathematics, Academia Sinica, beijing 100080,{2.)YANG Zhenhai(Institute of Statistics, beijing Polytechnic University, beijing 10002.,

For a general linear model, spherical distributions are often considered whenerrors do not have normal distribution. Several authors[1-3] studied the least squaresand James-Stein estimations for a linear model whose errors follow multivariate t or moregeneral spherical distributions. In this paper the test problem for sphericity of errors isconsidered. We propose an exact test for the sphericity by using the conditional probabilityintegral transformation and another transformation. As an important special case, thecorresponding test statistics for multivariate t distribution are obtained.

关键词： Spherical distribution multivariate t-distribution conditional probability integral transformation Pearson’s product test multivariate Cauchy distribution.

Novel synergic combinatorial photoelectrochemical technology for degradation of trace of 2.chlorophenol in drinking water

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chinese Science Bulletin 2003年第8期48卷 751-757页

作者： SONG Qiang & QU Jiuhui State Key lab. of Environmental Aquatic Chemistry, Research Center for Eco-environmental Science, chinese academy of sciences, {2. 100085, china Correspondence should be addressed to Qu Jiuhui (e-mail: jhqu@ ***) State Key lab. of Environmental Aquatic Chemistry Research Center for Eco-environmental Science Chinese Academy of Sciences Beijing 100085 China

A novel combinatorial photoelectrochemical (CPE) technology with combination of ultraviolet (UV)- photolysis and direct current (DC) electrolysis is studied and discussed for drinking water purification. In the self-made compositive photo-electrolysis incorporate reactor, removal rate of the 2.chlorophenol as model environmental pollutants has been investigated experimentally in terms of applied voltage, pH value, flow velocity, temperature, and aeration conditions. A primary analysis of the combinatorial photo-electric synergic effect on the degradation of organic pollut-ants has been carried out. It is found that the best perform-ance of CPE oxidation is achieved by the following condi-tions: DC voltage of 5.0 V combined with UV-2.4-raidation, near neutral of pH 8 with aeration of pure oxygen. The in-fluences of circular velocity, temperature, and initial concen-tration of the pollutant are minor. Under the optimal condi-tions, removal ratio of 2.CP is higher than 50% in 30 min, and 100% removal ratio of 2.CP (5 10-6) can be reached and TOC removal ratio reached above 90% in 2.5 h. Com-plete mineralization is achieved eventually. It shows in our investigation that under the studied conditions the synergic effect of UV photolysis and DC electrolysis on the degrada-tion of the model pollutant is remarkable and validated, which may be derived from the coexistence of mutual com-plementary mechanisms of photoelectrochemical action, and the radicals chain reactions resulted from photo activation and electrolysis excitation in the process of CPE oxidation.

关键词： 2.氯酚饮用水处理组合光电化学技术 CPE 紫外线

Prediction of Specific Region Cloud Cover Based on RBF Neural Networks

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Prediction of Specific Region Cloud Cover Based on RBF Neura...

A MULTIGRID METHOD FOR NONLINEAR PARABOLIC PROBLEMS

2.10 Second IITA International Conference on Geoscience and Remote Sensing (IITA-GRS 2.10)

作者： Fang Lu beijing Institute of applied Meteorology beijing china Zhigang Wang1 2.1. School of Mechatronical Engineering 2. lab of Computer Network Defense Technology beijing Institute of Technology beijing china

This paper presents a method based on RBF neural networks to predict the specific region cloud cover, which has the feature of time serial and nonlinear. Using this method, we can train the RBF neural networks and find out the nonlinear relations among historical cloud cover data, to predict future time of cloud cover. Experiment results show that the method provided a kind of viable intelligent way for the quantitative prediction of cloud cover.

关键词： prediction of cloud cover GMS-5 RBF neural networks

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Journal of Computational mathematics 1996年第4期14卷 363-382页

作者： x.J. Yu(laborutory of Computational Physics, Institute of applied Physics and Computational{2., beijing, china) INST APPL PHYS & COMPUTAT MATH LAB COMPUTAT PHYSBEIJINGPEOPLES R CHINA

The multigrid algorithm in [13] is developed for solving nonlinear parabolic equations arising from the finite element discretization. The computational cost of the algorithm is approximate O(NkN) where N-k is the dim... 详细信息

关键词： Th Math A MULTIGRID METHOD FOR NONLINEAR PARABOLIC PROBLEMS UC

Inclusion Complexation of β-CD with Phenothiazine and N-Alkylphenothiazine Derivatives

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chinese Chemical Letters 1998年第11期9卷 0-0,0-0页

作者： Wen Guang LI Xiu Qin RUAN Qing Xiang GUO You Cheng LIU (Institute of Chemical Metallurgy, chinese academy of sciences, beijing 100080)(National {2.oratory of applied Organic Chemistry, Lanzhou University, Lanzhou 730000)(Department of Chemistry, Univer chinese Acad Sci Inst Chem Met Beijing 100080 Peoples R China Lanzhou Univ Natl Lab Appl Organ Chem Lanzhou 730000 Peoples R China Univ Sci & Technol china Dept Chem Anhua 230026 Peoples R China

Inclusion of Acyclodextrin (ACD) with phenothiazine 1 and Nalkylpheno-thiazine derivatives (alkyl = ethyl 2. isobutyl 3 and isopentyl 4) in aqueous solution was studied by means of UV-vis spectroscopy. The association constant Ka values for the inclusion of β-CD with 1, 2. 3 and 4 were determined to be 188, 2.4, 12. and 80 L/mol, respectively. It indicates that the stability of the inclusion complexes is dependent on the structure and the volume of the substituents in the guest compounds.

关键词： β-cyclodextrin inclusion complex phenothiazine derivatives stability

ON THE COUPLING OF BOUNDARY INTEGRAL AND FINITE ELEMENT METHODS FOR SIGNORINI PROBLEMS

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Journal of Computational mathematics 1998年第6期16卷 561-570页

作者： Wei-jun Tang Hong-yuan Fu Long-jun Shen(laboratory of Computational Physics, Institute of applied Physics and Computational {2., P.O. Box 8009, beijing 100088, china) Inst Appl Phys & Computat Math Lab Computat Phys Beijing 100088 Peoples R China

In this paper, a exterior Signorini problem is reduced to a variational inequality on a bounded inner region with the help of a coupling of boundary integral and finite element methods. We established a equivalence between the original exterior Signorini problem and the variational inequality on the bounded inner region coupled with two integral equations on an auxiliary boundary. We also introduce a finite element approximation of the variational inequality and a boundary element approximation of the integral equations. Furthermore, the optimal error estimates are given.

关键词： boundary element finite element Signorini problems

Environmental　risk　assessment　of　the　middle　route　of　south－to－north　water　transferring　source　project　in　china

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Journal of Environmental sciences 1996年第3期8卷 285-291页

作者： Wang Huadong Wang Fei(Institute of Environmental sciences,beijing Normal University, beijing 100875, china) Institute of Environmental sciences Beijing Normal University Beijing 100875 China

This paper focused on the environment risk of the middle route of south-to-north water transferring source project in china. Analytic hierarchy process was applied to risk identification,fuzzy {2.-fault tree analysis to risk {2. assessment,statistics and analogy process to risk consequences assessment, lastly, grey relevant analysis and comprehensive index process to risk impact evaluation. The main environment risk accident of the project is dam failure, the main causative factors of the accident are catastrophic flood and wrecking earthquake. The flash flood, due to dam failure, will impact on nature, society and economy. The major environment risk areas are Jingzhou and Xiangfan,Hubei Province. The environment risk management measures should be adopted in order to ensure the safety of the project-environment complex system.

关键词： water source project environment risk risk assessment

LONG TIME ASYMPTOTIC BEHAVIOR OF SOLUTION OF DIFFERENCE SCHEME FOR A SEMILINEAR PARABOLIC EQUATION (Ⅱ)

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Journal of Computational mathematics 1998年第5期16卷 571-576页

作者： Hui Feng(Shenzhen University Normal College, Shenzhen 518060, china laboratorp of Computational Physics, Institute of {2. Physics and Computational mathematics,P.O.Box 8009, beijing 100088, china )Long-jnn Shen(laboratory of Computational Physics, In Shenzhen Univ Wormal Coll Shenzhen 518060 Peoples R China Inst Appl Phys & Computat Math Lab Computat Phys Beijing 100088 Peoples R China

In this paper we prove the solution of explicit difference scheme for a semilinear parabolic equation converges to the solution of difference scheme for the relevant nonlinear stationary problem as t→∞. For nonlinear parabolic problem, we obtain the long time asymptotic behavior of its discrete solution which is analogous to that of its continuous solution. For simplicity, we discuss one-dimensional problem.

关键词： Asymptotic behavior Explicit difference scheme Semilinear parabolic equation.

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PARM: a New QSAR Research Method Based on Genetic Algorithm

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chinese Chemical Letters 1997年第11期8卷 975-978页

作者： Hong Ming CHEN Jia Ju ZHOU Tian Rui REN Gui Rong XIE (laboratory of Computer Chemsitry, Institute of Chemical Metallurgy Chinses academy of {2., beijing 100080) chinese Acad Sci Inst Chem Met Lab Comp Chem Beijing 100080 Peoples R China

Based on Waiters' GERM([3])(Genetic Evolved Receptor Model) algorithm, an improved algorithm PARM(Pseudo Atomic Receptor Model) was put forward. FARM uses combination of genetic algorithm and cross-validation technique to produce atomic-level pseudo receptor model, based on a set of known structure-activity relationship. This algorithm has been applied to one system and afforded reasonable results. In recent years, there have appeared numerous computer programs([1,2.) which can build potential new ligands, based on three-dimensional structure of a receptor protein. Hower, in drug discovery, it is common to have measured activity data for a set of compounds acting upon a particular receptor protein but not to have knowledge of the three-dimensional structure of the protein active site. To solve this kind of problem, in present work, we put forward a FARM algorithm which was based on Waiters' GERM algorithm to predict bioactivity.

关键词： QSAR PARM