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FINITE ELEMENT DISPLACEMENT PERTURBATION METHOD FOR GEOMETRIC NONLINEAR BEHAVIORS OF SHELLS OF REVOLUTION OVERALL BEDING IN A MERIDIONAL PLANE AND APPLICATION TO BELLOW (Ⅱ)

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Applied Mathematics and Mechanics(English Edition) 2002年第12期23卷 1390-1406页

作者： ZHU wei-ping(朱卫平) HUANG Qian(黄黔) Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 P R China Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 P R China

The finite_element_displacement_perturbation method (FEDPM)for the geometric nonlinear behaviors of shells of revolution subjected to pure bending moments or lateral forces in one of their meridional planes (Ⅰ) was employed to calculate the stress distributions and the stiffness of the bellows. Firstly, by applying the first_order perturbation solution (the linear solution)of the FEDPM to the bellows, the obtained results were compared with those of the general solution and the initial parameter integration solution proposed by the present authors earlier, as well as of the experiments and the FEA by *** is shown that the FEDPM is with good precision and reliability, and as it was pointed out in (Ⅰ) the abrupt changes of the meridian curvature of bellows would not affect the use of the usual straight element. Then the nonlinear behaviors of the bellows were discussed. As expected, the nonlinear effects mainly come from the bellows ring plate,and the wider the ring plate is, the stronger the nonlinear effects are. Contrarily, the vanishing of the ring plate, like the C_shaped bellows, the nonlinear effects almost vanish. In addition, when the pure bending moments act on the bellows, each convolution has the same stress distributions calculated by the linear solution and other linear theories, but by the present nonlinear solution they vary with respect to the convolutions of the bellows. Yet for most bellows, the linear solutions are valid in practice.

关键词： shell of revolution bellows deflection by lateral force geometrical non_linearity perturbation technique finite element method

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Convenient Asymmetric Borane Reduction of Ketones Catalyzed by Simple Amino Alcohols and Corresponding Amino Acids

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Chinese Chemical Letters 2002年第12期13卷 1147-1148页

作者： Guo Bin SUN wei wei PEI Hui WANG wei ping YE College of Chemistry and Molecular Engineering Peking UniversityBeijing 100871

An asymmetric borane reduction of prochiral ketones catalyzed by simple amino alcohols and corresponding amino acids was examined to give alcohols with e.e. value up to 92% .

关键词： Enantioselective borane reduction amino alcohols amino acids ketones.

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Synthesis of New Ligand 1,2-Bis{di[(R,R)-1,3,2-oxzaphosphlidine]phosphino}ethane with C_2-symmetric Axis and Application in Rh-catalyzed Asymmetric Hydrogenation

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Chemical Research in Chinese Universities 2007年第5期23卷 544-548页

作者： GONG Da-chun ZHOU Hua wei ping OUYANG ping-kai College of Chemistry and Life Science China Three Gorges University Yichang 443001 P. R. China College of Life Science and Pharmacy Nanfing University of Technology Nanfing 210009 P. R. China

New ligand 1,2-bis{di[（R,R）-1,3,2-oxzaphosphlidine]phosphino}ethane [（R,R）-BDOPPEs 1,2,3 and 4] with C2-symmetric axis and bearing nitrogen and oxygen were synthesized from readily available optically active amino *** complexes with these ligands were highly enantioselective catalysts for asymmetric hydrogenation of N-benzoyldehydroamino acid derivatives and α-functionalized ketones in 99%*** 98%e.e.,*** new class of（R,R）-BDOPPEs 1,2,3 and 4 gave much more effectivity and enantionselectivity than their corresponding non-C2-asymmetric aminophosphine phosphinite.

关键词： (R, R) -BDOPPE C2-Symmetry Asymmetric catalytic hydrogenation

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Crystal Structure and Characterization of 2-N-(2-Hydroxy-benzylidene) Furanmethanoamine Nickel(II) Complex

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Chinese Journal of Structural Chemistry 2005年第8期24卷 909-912页

作者： WANG Jun XU Hong ZHOU Hua wei ping College of Life Science and Pharmaceutical Engineering Nanjing University of TechnologyChinaNanjing Jiangsu 210009 Department of Forensic Science Jiangsu Police Institute ChinaNanjing Jiangsu 210012

The Ni（Ⅱ） complex with ligand 2-N-（2-hydroxy-benzylidene） furanmethanoamine has been synthesized and characterized by elemental analysis, IR and single-crystal X-ray diffraction. It crystallizes in the monoclinic system, space group C2/c with a = 2.0280（4）, b =0.57700（12）, c = 1.7340（4） nm, β = 94.74（3）°, Z = 4, Dc = 1.508 g/cm^3, the final R = 0.0434 and wR = 0.1112 for 1843 observed reflections with 1 〉 2σ（I）. X-ray analysis revealed that the Ni（Ⅱ） ion is coordinated by two nitrogen atoms of Schiff base and two oxygen atoms of salicylaldehyde in the equatorial plane, and the coordination geometry can be described as a square.

关键词： nickel(Ⅱ) complex salicylaldehyde crystal structure furfuryl amine Schiff base

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MODIFICATION OF POLYETHYLENE BY in situ FORMED SODIUM ACRYLATE

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Chinese Journal of Polymer Science 2006年第6期24卷 559-567页

作者： Qing-quan Ke ping-kai Jiang ping wei Gen-lin Wang Cho-nung Kim School of Chemistry and Chemical Engineering Shanghai Jiao Tong University Shanghai 200240 China Shanghai Key Lab of Electric Insulation and Thermal Aging Shanghai 200240 China

To improve the water tree resistance of PE, linear low-density polyethylene （LLDPE） was compounded with sodium acrylate （NaAA） for in situ polymerization, in which NaAA was fbrmed through the neutralization of acrylic acid （AA） with sodium hydroxide （NaOH） before adding dicumyl peroxide （DCP） to initiate the in situ graft polymerization and homo polymerization. A series of LLDPE/NaAA compounds were investigated for their water absorption ratio （WAR） measurement, water treeing, mechanical and dielectric properties. The results strongly suggest that NaAA can improve the water tree resistance of LLDPE. In addition, the LLDPE/NaAA compounds possess satisfactory mechanical properties and dielectric properties. Characterization of LLDPE/NaAA compounds by using Fourier transform infrared spectrometry （FTIR） suggests that the neutralization and polymerization reaction could be achieved effectively. Using adequate DCP content is the key factor for controlling the polymerization of NaAA with precise conversion ratio.

关键词： Polyethylene Water trees Cable insulation Sodium acrylate.

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Does Green Food Certification promote agri-food export quality?Evidence from China

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Journal of Integrative Agriculture 2024年第3期23卷 1061-1074页

作者： ping wei Hongman Liu Chaokai Xu Shibin Wen College of Economics and Management China Agricultural UniversityBeijing 100083China School of Public Affairs Zhejiang UniversityHangzhou 310058China

The construction of a food certification system plays a vital role in upgrading export quality, which previous studies have largely overlooked. We match China's industry-level data of Green Food Certification with its HS6-digit export data of agri-food products to quantify the impact of Green Food Certification on export quality. We identify the significant and positive effect of Green Food Certification on export quality. The 2SLS estimation based on instrumental variables and a range of robustness checks confirm the validity and robustness of the benchmark conclusions. Further analysis discloses that Green Food Certification improves export quality by raising agricultural production efficiency and brand premiums. Heterogeneity analysis shows that the effect of Green Food Certification varies across regions, notably improving the quality of agri-food products exported to developed regions and regions with high levels of import supervision. Furthermore, among various product types, Green Food Certification significantly improves the export quality of primary products and products vulnerable to non-tariff measures. The above findings could guide the future development of agri-food quality certification systems, potentially leading to a transformation and promotion of the agri-food trade.

关键词： Green Food Certification agri-food products green transformation export quality food labeling

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The equivalence on classical metrics

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Science China Mathematics 2007年第2期50卷 183-200页

作者： wei-ping Yin An WANG School of Mathematical Sciences Capital Normal UniversityBeijing 100037China

In this paper we study the complete invariant metrics on Cartan-Hartogs domains which are the special types of Hua domains. Firstly, we introduce a class of new complete invariant metrics on these domains, and prove that these metrics are equivalent to the Bergman metric. Secondly, the Ricci curvatures under these new metrics are bounded from above and below by the negative constants. Thirdly, we estimate the holomorphic sectional curvatures of the new metrics, and prove that the holomorphic sectional curvatures are bounded from above and below by the negative constants. Finally, by using these new metrics and Yau’s Schwarz lemma we prove that the new metrics are equivalent to the Einstein-K?hler metric. That means that the Yau’s conjecture is true on Cartan-Hartogs domains.

关键词： Bergman metric Einstein-Kahler metric Cartan-Hartogs domain equivalence on classical metrics

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A NEW METHOD OF CHANNEL FRICTION INVERSION BASED ON KALMAN FILTER WITH UNKNOWN PARAMETER VECTOR

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Journal of Hydrodynamics 2005年第6期17卷 693-698页

作者： CHENG wei-ping MAO Gen-hai LIU Guo-hua College of Civil Engineering and Architecture Zhejiang University Hangzhou 310027 China

Channel friction is an important parameter in hydraulic analysis. A channel friction parameter inversion method based on Kalman Filter with unknown parameter vector is proposed. Numerical simulations indicate that when the number of monitoring stations exceeds a critical value, the so lution is hardly affected. In addition, Kalman Filter with unknown parameter vector is effective only at unsteady state. For the nonlinear equations, computations of sensitivity matrices are time-costly. Two simplified measures can reduce computing time, but not influence the results. One is to reduce sensitivity matrix analysis time, the other is to substitute for sensitivity matrix.

关键词： channel inversion Kalman Filter with unknown parameter vector friction

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Preparation and anti atomic oxygen erosion properties of OPPOSS/PI composites

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International Journal of Minerals,Metallurgy and Materials 2013年第10期20卷 994-1000页

作者： wei-ping Li Hui-cong Liu Li-li Feng School of Materials Science and Engineering Beihang University Key Laboratory of Urban Stormwater System and Water Environment (Ministry of Education) Beijing University of CivilEngineering and Architecture

Atomic oxygen （AO） found in low earth orbit can cause serious erosion to polyimide （PI） materials, which greatly limits their lifetime. 8-phenyl silsesquioxane （OPPOSS） was synthesized, and OPPOSS/PI composites were pre- pared by physical blending, followed by thermal imidization to enhance the AO erosion resistance of PI materials. The morphology, composition, and structure of the composites were analyzed before and after AO exposure in a ground sim- ulated facility of atomic oxygen. After 16 h AO exposure, the OPPOSS/PI composite with 5wt% OPPOSS addition shows an erosion rate of about 1.4×10-24 cm3/atom with only 48% mass loss of that of PI without OPPOSS addition. The mixture of OPPOSS nano molecules is assembled into a kind of regular square structure and distributed evenly in OPPOSS/PI composites. Some SiO2 particles are formed in the composites during AO exposure, which can act as ＂inert points＂ to reduce the AO erosion rate of OPPOSS/PI composites.

关键词： composite materials polyimides silsesquioxanes atomic oxygen erosion

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Numerical simulation of tritium behavior under a postulated accident condition for CFETR TEP system

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Nuclear Science and Techniques 2023年第7期34卷 206-218页

作者： Hai-Xia Wang Xue-wei Fu wei-ping Liu Tao-Sheng Li Jie Yu Institute of Nuclear Energy Safety Technology Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China

China Fusion Engineering Test Reactor(CFETR)is China's self-designed and ongoing next-generation fusion reactor *** confinement systems in CFETR guarantee that the radiation level remains below the safety limit during tritium handling and operation in the fuel cycle *** tritium technology team is responsible for studying tritium transport behavior in the CFETR tritium safety confinement systems of the National Key R&D Program of China launched in 2017,and we are conducting CFETR tritium plant safety analysis by using CFD *** this paper,the tritium migration and removal behavior were studied under a postulated accident condition for the Tokamak Exhaust Processing system of *** quantitative results of the transport behavior of tritium in the process room and glove box during the whole accident sequence(e.g.,tritium release,alarm,isolation,and tritium removal)have been *** results support the detailed design and engineering demonstration-related research of CFETR tritium plant.

关键词： China Fusion Engineering Test Reactor(CFETR) Tokamak Exhaust Processing(TEP)system Numerical simulation Tritium transport behavior Tritium confinement system Accident condition

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