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Thermodynamic Assessment of Reactions between Yttrium and Tramp Elements in Petroleum Pipe Steel

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International Journal of Minerals,Metallurgy and Materials 1998年第4期12卷 219-222页

作者： Aixue Sha Luren Dong Shangyi Li( Metallurgy school, University of science and Technology Beijing, Beijing 1 00083, china)(science and Technology department, Metallurgical Industry Bureau of china, Beijing 100711, china) Metallurgy school University of Science and Technology Beijing Beijing 100083 China science and Technology department Metallurgical Industry Bureau of China Beijing 100711 China

In the thermodynamic evaluation Y was selected as a typical heavy rare earth metal for reducing the detrmental effects of tramp elements in the petroleum pipe steel. The possibilities of reactions between Y and trampelements such as Sn, Sb, As, etc. after deoxidation and desulphurization were estimated by calculating the Gibbsfree energies of formation. The equilibrium content of Y for eliminating the detrimental effects of tramp elements inthe steel was recommended from the results of thermodynamic calculation.

关键词： rare earth metals tramp elements thermodynamic calculation

INFLUENCES OF ANISOTROPY ON BAND GAPS OF 2D PHONONIC CRYSTAL

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Acta Mechanica Solida Sinica 2010年第2期23卷 181-188页

作者： Zhengqiang Zhan Peijun Wei 1(department of Mathematics and Mechanics,school of Applied science,University of science and Technology Beijing,Beijing 100083,china) [a] department of Mathematics Mechanics School of Applied Science University of Science Technology Beijing Beijing 100083 China

Band gaps of 2D phononic crystal with orthotropic cylindrical fillers embedded in the isotropic host are studied in this paper. Two kinds of periodic structures, namely, the square lattice and the triangle lattice, are considered. For anisotropic phononic crystal, band gaps not only depend on the periodic lattice but also the angle between the symmetry axis of orthotropic material and that of the periodic structure. Rotating these cylindrical fillers makes the angle changing continuously; as a result, pass bands and forbidden bands of the phononic crystal are changed. The plane wave expansion method is used to reduce the band gap problem to an eigenvalue problem. The numerical example is given for YBCO/Epoxy composites. The location and the width of band gaps are estimated for different rotating angles. The influence of anisotropy on band gaps is discussed based on numerical results.

关键词： phononic crystal orthotropy band gap periodicity plane wave expansion

The effects of relative density of metal foams on the stresses and deformation of beam under bending

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Acta Mechanica Sinica 2007年第4期23卷 409-414页

作者： Aiyu Zhu Tianyou Fan department of Mathematics,school of science,Beijing Institute of Technology,P.O.Box 327,Beijing 100081,china department of Physics,school of science,Beijing Institute of Technology,P.O.Box 327,Beijing 100081,china department of Mathematics School of Science Beijing Institute of Technology P. O. Box 327 Beijing 100081 China department of Physics School of Science Beijing Institute of Technology P. O. Box 327 Beijing 100081 China

The exact analytic solution of the pure bending beam of metallic foams is given. The effects of relative density of the material on stresses and deformation are revealed with the Triantafillou and Gibson constitutive law （TG model） taken as the analysis basis. Several examples for individual foams are discussed, showing the importance of compressibility of the cellular materials. One of the objects of this study is to generalize Hill＇s solution for incompressible plasticity to the case of compressible plasticity, and a kinematics parameter is brought into the analysis so that the velocity field can be determined.

关键词： Metal foams - Relative density Compressible plasticity Constitutive law - TG model

DYNAMIC CHARACTERISTICS OF LIQUID FORCED SLOSHING IN A TURNING SPHERICAL TANK WITH A SPACER UNDER LOW GRAVITY

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Journal of Hydrodynamics 2008年第2期20卷 202-209页

作者： CHENG Xu-duo HU Mei-zhu WEN Ji-hua school of food science and Engineering Nanjing University of Finance and Economics Nanjing 210003China department of Physics Anqing Teachers College Anging 246011 China

Under the condition of low gravity the characteristics of liquid forced sloshing in a turning spherical tank with a spacer were investigated. The static shape of the liquid surface was analyzed. By expanding the characteristic functions, the frequencies and velocity potential of liquid free-sloshing were derived. The governing equations and boundary conditions for the forced sloshing of liquid under the tank turning were established. The transverse force of liquid acting on the tank and the moment of force to the centre of the tank which is caused by the force of liquid acting on the spacer were given. Numerical results were compared with the ones of the spherical tank without a spacer. The results show that when a spacer is inserted in the tank, the sloshing frequency of liquid and the transverse force of liquid acting on the tank will decrease, but the moment of force to the centre of the tank which is caused by the force of liquid acting on the spacer will occur.

关键词： low gravity forced sloshing of liquid sloshing suppression

Reduction of Chilling Injury and Ultrastructural Damage in Cherry Tomato Fruits After Hot Water Treatment

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Agricultural sciences in china 2009年第3期8卷 304-310页

作者： YANG Jing, FU Mao-run, ZHAO Yu-ying and MAO Lin-chun department of food science and Nutrition, College of Biosystem Engineering and food science, Zhejiang University, Hangzhou 310029, P.R.china [a]department of food science and Nutrition College of Biosystem Engineering and Food Science Zhejiang University Hangzhou 310029 P.R. China

The effects of hot water treatment in alleviating chilling injury and reducing ultrastructural damage of mature-green cherry tomatoes （Lycopersicun esculentum cv. cerasiform Alef） were investigated. Mature-green cherry tomato fruits were treated in water at 40℃ or 45℃ for 5 min or 15 min, and then stored at 5℃ for 19 days followed by ripening at 20℃. Water treatment at 40℃ for 15 min increased tolerance of cherry tomato fruits to chilling stress, indicating as low outbreak of skin lesion, high color a＊ value, and low electrolyte leakage. Treated fruits showed typical climacteric respiration and developed normal red color with chlorophyll degradation and lycopene accumulation during ripening, while fruits without treatment failed to develop red color and suffered skin lesion. After 19 days of chilling, heated fruits showed the conversion of chloroplast to chromoplast with the disappearance of thylakoids. Mitochondria and other cell organelles were not adversely affected in treated fruits. However, ultrastructures in pericarp cells in control fruits severely damaged with extensive disorganization of cytoplasm, swelled chloroplasts, distorted and unstacked thylakoids. Chloroplast was the first and most severely impacted organelle by chilling stress. Hot water treatment （40℃ for 15 min） before storage alleviated chilling injury in cherry tomato fruits. The results suggest that chilling injury is related with the damage of cell structure under chilling stress.

关键词： cherry tomato chilling injury heat treatment ultrastructure

DYNAMIC CHARACTERISTICS OF LIQUID SLOSHING IN A TRANSVERSELY VIBRATING SPHERICAL TANK WITH A SPACER UNDER LOW GRAVITY

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Journal of Hydrodynamics 2008年第6期20卷 762-769页

作者： CHENG Xu-duo HU Mei-zhu WEN Ji-hua school of food science and Engineering Nanjing University of Finance and Economics Nanjing 210003 China department of Physics Anqing Teachers College Anqing 246011 China

The dynamic characteristics of liquid sloshing in a transversely vibrating spherical tank with spacer under low gravity were investigated. By expanding the characteristic functions, the frequencies and velocity potentials of liquid free-sloshing were obtained. The dynamic equations and boundary conditions of liquid sloshing in the traverse vibrational spherical tank with spacer under low gravity were derived. By modifying the velocity potentials of liquid free-sloshing, the velocity potentials of liquid sloshing in the traverse vibrating spherical tank with a spacer were obtained. Furthermore, the forces and the moments acting on tank wall were given. The numerical results show when a spacer is inserted in the tank, the sloshing frequencies of liquid and the forces acting on tank wall will decrease, but the moment of force to the centre of the tank which is caused by the force of liquid acting on the spacer will occur.

关键词： low gravity liquid forced sloshing sloshing suppression

Hybrid of comprehensive learning particle swarm optimization and SQP algorithm for large scale economic load dispatch optimization of power system

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science china(Information sciences) 2010年第8期53卷 1566-1573页

作者： WANG Yu , LI Bin & YUAN Bo department of Electronic science and Technology, school of Information science and Technology, University of science and Technology of china, Hefei 230027, china 1. department of Electronic science and Technology School of Information Science and Technology University of Science and Technology of China Hefei 230027 China

Economic load dispatch (ELD) is an important optimization task in power systems. In the previous works, various researchers attempted to address this problem by both mathmatical and heuristic optimization algorithms. However, there are still two practically important issues that have not attracted sufficient attention: 1) the stability of these algorithms cannot be effectively ensured; 2) the performance of these algorithms on large scale ELD optimization tasks remains to be unsatisfactory. CLPSO is an effective global optimization algorithm. To strengthen the convergence ability of CLPSO, the sequential quadratic programming (SQP) is introduced into it. This results in a new algorithm hybrid of comprehensive learning particle swarm optimization and sequential quadratic programming (SQP-CLPSO). To assess the performance of SQP-CLPSO, it is compared with several state-of-the-art evolutionary algorithms (EAs) on the classical ELD optimization problems. Experimental results show that SQP-CLPSO has very good abilities of convergence, diversity maintainence and scalability, which make it suitable for complex ELD problems.

关键词： particle swarm optimization comprehensive learning particle swarm optimization sequential quadratic programming local search power systems economic load dispatch

Asymptotic normality and strong consistency of maximum quasi-likelihood estimates in generalized linear models

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science china Mathematics 2006年第2期49卷 145-157页

作者： YIN Changming, ZHAO Lincheng & WEI Chengdong school of Mathematics and Information science, Guangxi University, Manning 530004, china department of Statistics and Finance, University of science and Technology of china, Hefei 230026, china department of Mathematics, Guangxi Teacher College, Manning 530001, china 1. school of Mathematics and Information science Guangxi University Nanning 530004 China 2. department of Statistics and Finance University of Science and Technology of China Hefei 230026 China 3. department of Mathematics Guangxi Teacher College Nanning 530001 China

In a generalized linear model with q x 1 responses, the bounded and fixed (or adaptive) p × q regressors Zi and the general link function, under the most general assumption on the minimum eigenvalue of ZiZ'i,the moment condition on responses as weak as possible and the other mild regular conditions, we prove that the maximum quasi-likelihood estimates for the regression parameter vector are asymptotically normal and strongly consistent.

关键词： generalized linear models quasi-likelihood estimates asymptotic normality strong consistency.

Fast Fourier-Galerkin methods for first-kind logarithmic-kernel integral equations on open arcs

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science china Mathematics 2010年第1期53卷 1-22页

作者： WANG Bo1,WANG Rui2 & XU YueSheng3,4,1Academy of Mathematics and Systems science,Chinese Academy of sciences,Beijing 100190,china 2school of Information science and Engineering,Graduate University of the Chinese Academy of sciences,Beijing 100190,china 3department of Mathematics,Syracuse University,Syracuse,NY 13244,USA 4department of Scientific Computing and Computer Applications,Sun Yat-sen University,Guangzhou 510275,china 1. Academy of Mathematics and Systems science Chinese Academy of Sciences Beijing 100190 China2. School of Information Science and Engineering Graduate University of the Chinese Academy of Sciences Beijing 100190 China3. Department of Mathematics Syracuse University Syracuse NY 13244 USA4. Department of Scientific Computing and Computer Applications Sun Yat-sen University Guangzhou 510275 China

We propose a fully discrete fast Fourier-Galerkin method for solving an integral equation of the first kind with a logarithmic kernel on a smooth open arc,which is a reformulation of the Dirichlet problem of the Laplace equation in the *** optimal convergence order and quasi-linear complexity order of the proposed method are established.A precondition is *** this method with an efficient numerical integration algorithm for computing the single-layer potential defined on an open arc,we obtain the solution of the Dirichlet problem on a smooth open arc in the *** examples are presented to confirm the theoretical estimates and to demonstrate the efficiency and accuracy of the proposed method.

关键词： Dirichlet problem open arc singular boundary integral equations Fourier-Galerkin methods logarithmic potentials