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Numerical Simulation of Superplastic Forming and Diffusion bonding of Ti Alloys

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Journal of Materials Science & Technology 2003年第Z1期19卷 46-48页

作者： Kaifeng ZHANG Wenbo HAN Wei WU Guofeng WANG Dezhong WU School of Materials Science and Engineering Habin Institute of Technology Harbin 150001 China School of Materials Science and Engineering Habin Institute of Technology Harbin 150001 China School of Materials Science and Engineering Habin Institute of Technology Harbin 150001 China School of Materials Science and Engineering Habin Institute of Technology Harbin 150001 China School of Materials Science and Engineering Habin Institute of Technology Harbin 150001 China

The research on numerical simulation for combinative process of SPF/DB is carried out in this paper. The contacting problem of sheets is analyzed by using the penalty method. In order to solve the contact problem of different parts of the sheet, a new algorithm for contacting judgment is proposed. According to the relation of the distance vector and the vector of contacting element area, and the condition of contact, it can be judged whether or not a node on the slave surface and the corresponding master surface are in the state of SPF/DB. The Mindlin shell element is employed to simulate SPF/DB process of an asymmetry double-cell cup of Ti-6Al-4V to examine the efficiency of the new algorithm using ARVIP-3D. The results of the numerical simulation are in good agreement with experimental results.

关键词： Numerical simulation, Superplastic forming, Diffusion bonding, Contact search algorithm

bonding in [CuNRR′]4 type clusters

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Science China Chemistry 2004年第3期47卷 179-183页

作者： WANG Bingwu XU Guangxian CHEN Zhida State Key Laboratory of Rare Earth Materials Chemistry and Applications College of Chemistry and Molecular Engineering Peking University Beijing 100871 China State Key Laboratory of Rare Earth Materials Chemistry and Applications College of Chemistry and Molecular Engineering Peking University Beijing 100871 China State Key Laboratory of Rare Earth Materials Chemistry and Applications College of Chemistry and Molecular Engineering Peking University Beijing 100871 China

Many polynuclear Cu(I) compounds have been synthesized, but the problem whether there is direct or no direct Cu-Cu bonding in these compounds is not clear. The electronic structure of [CuNRR′]4 type clusters was investigated by using density functional methods. The results of geometrical optimization are in good agreement with experiment, and the localization of MO’s shows that there are four Cu-Cu s bonds to form the square Cu4 ring in addition to the four bridging Cu-N-Cu bonds. A concept of the covalence of molecular fragments is proposed to describe the bonding in these clusters.

关键词： inorganic fullerene-like molecule, chemical bonding, covalence, copper.

Wafer bonding technique used for the integration of cubic GaN/GaAs (001) with Si substrate

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Science China(Technological Sciences) 2002年第3期45卷 255-260页

作者：孙元平付羿渠波王玉田冯志宏沈小明赵德刚郑新和段俐宏李秉臣张书明杨辉姜晓明郑文莉贾全杰 State Key Laboratory on Integrated Optoelectronics Institute of Semiconductors Chinese Academy of Sciences Beijing China Synchrotron Radiation Laboratory Institute of High Energy Physics Chinese Academy of Sciences Beijing China

We successfully used the metal mediated-water bonding technique in transferring the as-grown cubic GaN LED structure of Si substrate. The absorbing GaAs substrate was removed by using the chemical solutions of NH4OH:H2O2=1:10. SEM and PL resuls show that water bonding technique could transfer the cubic GaN epilayers uniformly to Si without affecting the physical and optical properties of epilayers. XRD result shows that there appeared new peaks related to AgGa2 and Ni4N diffraction, indicating that the metals used as adhesive and protective layers interacted with the p-GaN layer during the long annealing process. It is just the reaction that ensures the reliability of the integration of GaN with metal and minor contact resistance on the interface.

关键词： wafer bonding, cubic, GaN/GaAs(001), Si-substrate.

Study on the covalence of Cu and chemical bonding in an inorganic fullerene-like molecule,[CuCl]_(20)[Cp^(*)FeP_(5)]_(12)[Cu-(CH_(3)CN)_(2)^(+)Cl^(-)]_(5),by a density functional approach

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Science China Chemistry 2004年第2期47卷 91-97页

作者： WANG Bingwu XU Guangxian CHEN Zhida State Key Laboratory of Rare Earth Materials Chemistry and Applications College of Chemistry and Molecular Engineering Pekin University Beijing 100871 China State Key Laboratory of Rare Earth Materials Chemistry and Applications College of Chemistry and Molecular Engineering Pekin University Beijing 100871 China State Key Laboratory of Rare Earth Materials Chemistry and Applications College of Chemistry and Molecular Engineering Pekin University Beijing 100871 China

The electronic structure and chemical bonding in a recently synthesized inorganic fullerene-like molecule, [CuCl]20[Cp*FeP5]12[Cu-(CH3CN) + 2Cl?]5 has been studied by a density functional approach. Geometrical optimization of the three basic structural units of the molecule is performed with Amsterdam Density Functional Program. The results are in agreement with the experiment. Localized MO’s obtained by Boys-Foster method give a clear picture of the chemical bonding in this molecule. The reason why CuCl can react with Cp*FeP5 in solvent CH3CN to form the fullerene-like molecule is explained in terms of the soft-hard Lewis acid base theory and a new concept of covalence.

关键词： inorganic fullerene-like molecule, chemical bonding, covalence, copper.

Study on the construction of satisfactory nonorthogonal localized molecular orbitals

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Science China Chemistry 2004年第1期47卷 1-9页

作者： FENG Huasheng BIAN Jiang LI Lemin State Key Laboratory of Rare Earth Materials and Applications College of Chemistry and Molecular Engineering Peking University Beijing 100871 China State Key Laboratory of Rare Earth Materials and Applications College of Chemistry and Molecular Engineering Peking University Beijing 100871 China State Key Laboratory of Rare Earth Materials and Applications College of Chemistry and Molecular Engineering Peking University Beijing 100871 China

Comparing to orthogonal localized molecular orbitals (OLMO), the nonorthogonal localized molecular orbitals (NOLMO) exhibit bonding pictures more accordant with those in the traditional chemistry. They are more contracted, so that they have a better transferability and better performances for the calculation of election correlation energies and for the linear scaling algorithms of large systems. The satisfactory NOLMOs should be as contracted as possible while their shapes and spatial distribution keep in accordance with the traditional chemical bonding picture. It is found that the spread of NOLMOs is a monotonic decreasing function of their orthogonality, and it may reduce to any extent as the orthogonality descends. However, when the orthogonality descends to some point, the shapes and spatial distribution of the NOLMOs deviate drastically from the traditional chemical bonding picture, and finally the NOLMOs tend to linear dependence. Without the requirement of orthogonalization, some other constraints have to be imposed for constructing satisfactory NOLMOs by minimizing their spread functional. It is shown that satisfactory results can be generated by coupling the minimization of orbital spread functionals with the maximization of the distances between orbital centroids.

关键词： quantum chemical calculation, chemical bonding, nonorthogonal localized molecular orbital, orbital spread.

Different properties of GaN-based LED grown on Si(111) and transferred onto new substrate

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Science China(Technological Sciences) 2006年第3期49卷 313-321页

作者： XIONG Chuanbing JIANG Fengyi FANG Wenqing WANG Li LIU Hechu MO Chunnan Nanchang University Education Ministry Engineering Research Center for Luminescence Materials and Devices Nanchang 330047 China Nanchang University Education Ministry Engineering Research Center for Luminescence Materials and Devices Nanchang 330047 China Nanchang University Education Ministry Engineering Research Center for Luminescence Materials and Devices Nanchang 330047 China Nanchang University Education Ministry Engineering Research Center for Luminescence Materials and Devices Nanchang 330047 China Nanchang University Education Ministry Engineering Research Center for Luminescence Materials and Devices Nanchang 330047 China Nanchang University Education Ministry Engineering Research Center for Luminescence Materials and Devices Nanchang 330047 China

InGaN MQW LEDs, grown by metal-organic chemical vapor deposition (MOCVD) on Si(111) substrates, were successfully bonded and transferred onto new Si substrate. After chemical etching Si(111) substrate and inductively coupled plasma (ICP) etching the transferred LED film to Si-doped layer, a vertical structure GaN blue LEDs were then fabricated. The characteristics of the lateral structure LED (grown on Si) and the vertical structure LED (bonded on Si) were investigated. It shows the performance of ver- tical structure LEDs had obviously been improved compared to the lateral structure LEDs and the tensile stress in GaN layer of vertical structure LEDs is smaller than that in lateral structure LEDs.

关键词： GaN, LEDs, Si, wafer bonding, vertical structure.

Metaphors of Anorexia Analysis of Peony＇s Starved-for-loveSelf in Lisa See＇s Peony in Love

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Journal of Literature and Art Studies 2017年第6期7卷 663-669页

作者： ZHANG Na Guangdong University of Foreign Studies Guangzhou China

In Asian American writer Lisa See＇s novel Peony in Love （2007）, the love-sick maiden Peony commits anorexiawhich finally leads to her annihilation. Anorexia, as well as foot bonding, both of which are distortions of femalebody, convey various metaphors. The novel repeatedly presents the inability to eat or eating monotonous meals assymptoms of the nervous breakdown. Through a series of feminist psychological analysis, this paper is designed tofigure out these metaphors of anorexia within the text in the following three dimensions： anorexia as imitation of art,anorexia as failure in mother-daughter relationship and the anorexic female body as a language. After explanationsof the metaphorical meaning of anorexia, this paper aims to analyze Peony＇s starved-for-love self, and draw aconclusion about lovesickness during the whole process of Peony＇s maturation.

关键词： anorexia, foot bonding, female body, feminist psychology, lovesick

Creation of Functional Organic Gels Based on Oligothiophenes

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合成化学 2004年第Z1期12卷 55-55页

作者： Liu Ping , Zhao Qi-zhong , Hu Jian-hua , Zhou Xiao-ping , Deng Wen-ji , Xu Yun-hua ?1 1 1 1 2 2 1. Research Institute of Materials Science, South China University of Technology, Guangzhou 510640, China 2. Department of Applied Physics, South China University of Technology, Guangzhou 510640, China) Research Institute of Materials Science South China University of Technology Guangzhou 510640 China Department of Applied Physics South China University of Technology Guangzhou 510640 China

Polymer gels have received a great deal of attention not only from scientific interest but also for their practical applications. Recently, low molecular-weight organic gels have also been receiving growing attention. However, their have been few studies of low molecular-weight organic gels in contrast to extensive studies of polymer *** order to develop a novel class of low-molecular-weight organic gels and to gain an insight into the relationship between molecular structures of gel-forming compounds and gel-forming properties, a novel family of low molecular-weight organic compounds containing oligothiophene,N,N'-distearyl-5,5'-(2,2':5',2'-terthiophe-ne)dicarboxamide(DNC183T),N,N'-dialkyl-5,5'-(3,3'-dioctyl-2,2':5',2'-terthiophene)dicarboxamide(DNCnDOc3T, n = 5, 8, 16, 18)and N,N'-distearyl-5,5''-( 3,3''-dioctyl- 2,2':5',2 ':5',2''-quaterthiophene)dicarboxamide(DNC1sDOc4T), were designed and synthesized. Whereas DNC183T did not form gels with organic solvents, DNCnDOc3T(n = 8, 16, 18) and DNC18DOc4T were found to form gels with certain organic solvents. These are the first examples of low molecular-weight organic gels containing an oligothiophene moiety. It is of intest to note that while DNC8DOc3T forms opaque gels with alcohols,e.g. ethanol and isopropanol, DNC16DOc3T, DNC18DOc3T and DNC18DOc4Tform transparent gels with hydrocarbon solvents such as heptane, octane, undecane, and others. It is shown that the intermolecular hydrogen bonding and intermolecular interactions between the long alkyl chain in the N-alkylcarboxamide group as well as the incorporation of an alkyl group at the β-position of the thiophene ring play an important role for the formation of gels. The optical micrographs of gels and the SEM images of xerogels showed three-dimensional networks of fibrous bundle ***18DOc4T gels was found to exhibit a reversible clear color change on electrochemical oxidation and reduction. Thus, low molecular-weight organic gels function as a new ty

关键词： Organic gel, oligothiophene, intermolecular hydrogen bonding, electrochromic materials.