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SYNTHESIS OF POLY(VINYL ACETATE)-INTERCALATED GRAPHITE OXIDE BY AN IN SITU INTERCALATIVE POLYMERIZATION

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Chinese Journal of Polymer Science 2000年第5期18卷 413-418页

作者： Ping-gui Liu Peng Xiao Min Xiao Ke-cheng Gong beijing Institute of Aeronautical Materials, beijing 100095, china Polymer Structure & Modification lab, South china University of Technology, Guangzhou 510640, china 北京航空材料研究院北京华南理工大学广东广州

Graphite oxide, a pseudo-two-dimensional solid in bulk form, was synthesized from natural graphite powder by oxidization with KMnO4 in concentrated H2SO4. The poly(vinyl acetate)-intercalated graphite oxide nano-composite was prepared by an in situ intercalative polymerization reaction, in which n-octanol-graphite oxide intercalation compounds were first obtained, vinyl acetate monomer was then dispersed into the interlayer of modified graphite oxide, followed by thermal polymerization of the monomer. It was experimentally shown that the c-axis space of poly(vinyl acetate)-intercalated graphite oxide was increased to 0.115 nm, which suggested there existed a monolayer of poly(vinyl acetate) chain between the layers of graphite oxide. The nanocomposite was also characterized with thermal analysis and FT-IR spectrometry.

关键词： graphite oxide poly(vinyl acetate) intercalate

On some tests-based projection pursuit for elliptical symmetry of a high-dimensional distribution

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Chinese Science Bulletin 1998年第6期43卷 450-458页

作者： JING Ping 1 and ZHU Lixing 2 1. Mathematics lab, china University of Mining & Technology, beijing 100083, china 2. Probability lab, Institute of Applied Mathematics, Chinese Academy of Sciences, beijing 100080, china Mathematics lab China University of Mining & Technology Beijing China Probability lab Institute of Applied Mathematics Chinese Academy of Sciences Beijing China

Some test statistics of Kolmogorov type and Cramér-von Mises type based on projection pursuit technique are proposed for the testing problem of sphericity of a high-dimensional distribution. The limiting distributions of the test statistics are derived under the null hypothesis and under any fixed alternative. The asymptotic properties of bootstrap approximation are investigated. Furthermore, for computational reasons, an approximation for the statistics, based on the number theoretic method, is suggested.

关键词： bootstrap approximation projection pursuit type statistic elliptical symmetry.

Threshold quantum secure direct communication without entanglement

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Science china(Physics,Mechanics & Astronomy) 2008年第2期51卷 176-183页

作者： YANG YuGuang1,3 & WEN QiaoYan2 1 College of Computer Science and Technology, beijing University of Technology, beijing 100022, china 2 School of Science, beijing University of Posts and Telecommunications, beijing 100876, china 3 State Key laboratory of Information Security (Graduate School of Chinese Academy of Sciences), beijing 100049, china College of Computer Science and Technology Beijing University of Technology Beijing China State Key laboratory of Information Security (Graduate School of Chinese Academy of Sciences) Beijing China School of Science Beijing University of Posts and Telecommunications Beijing China

For the first time, a threshold quantum secure direct communication (TQSDC) scheme is presented. Similar to the classical Shamir's secret sharing scheme, the sender makes n shares, S1, …, Sn of secret key K and each receiver keeps a share secretly. If the sender wants to send a secret message M to the receivers, he en-codes the information of K and M on a single photon sequence and sends it to one of the receivers. According to the secret shares, the t receivers sequentially per-form the corresponding unitary operations on the single photon sequence and ob-tain the secret message M. The shared shares may be reusable if it can be judged that there is no eavesdropper in line. We discuss that our protocol is feasible with current technology.

关键词： quantum secure direct communication threshold secure direct communication quantum secret sharing

Investigation of Cold Rolling Texture and Recrystallization Texture in NiW Substrates

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稀有金属材料与工程 2011年第S3期40卷 329-333页

作者： Tian Hui, Suo Hongli, Qiu Huoqin, Liu Min, Ma Lin, Wang Limin, Yuan Dongmei, Wang Yingxia beijing University of Technology, beijing 100124, china beijing Univ Technol Coll Mat Sci & Engn Beijing 100124 Peoples R China

NiW alloys were fabricated by cold isostatic pressing, the W content being 5, 7 and 9.3 at%, respectively. The NiW substrates were obtained by rolling assisted biaxially texturing. The cold rolling and recrystallization textures of NiW substrates were systematically studied by X-ray and EBSD, which revealed a variation of rolling texture in NiW substrates with increasing W content, which also influenced the copper (C) type and brass (B) type texture, as well as the transition between them. In addition, the recrystallization texture was influenced by the cold rolling texture. The main observations are: (1) Deformation twinning and orientation banding attributed to the cross slip and it is strongly related to the stacking fault energy which has a decisive effect on the texture transition from C to B type texture in NiW substrates with the W content increase. (2) The recrystallization cube texture is strongly related to the rolling texture. The C type texture was obtained in Ni5W substrates with 99% reduction, and was beneficial for the formation of the cube texture after recrystallization. The B type texture was obtained in Ni9W substrates with 99% reduction, and it was hard to obtain the cube texture, where a large number of annealing twins were formed during recrystallization process, leading to the formation of rotating cube texture, and thereby affecting the formation of sharp cube texture in Ni9W substrate.

关键词： NiW alloy cold rolling texture C type texture B type texture recrystallization texture

Reduced analysis and confirmatory research on co-adaptability theoretical solution to conflicting events in construction engineering projects

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Science china(Technological Sciences) 2010年第2期53卷 480-485页

作者： HOU XueLiang1 , LU Mei2 & WANG Kai3 1 School of Business Administration, North china Electric Power University, beijing 102206, china 2 Department of Construction Management, Tsinghua University, beijing 100084, china 3 College of Management, beijing Jiaotong University, beijing 100084, china School of Business Administration North China Electric Power University Department of Construction Management Tsinghua University College of Management Beijing Jiaotong University

The co-adaptability theoretical solution to conflicting events in construction engineering projects has three problems. First, the transformation of constraint conditions of theoretical solution is very difficult in practical engineering applications; second, some coefficients are difficult to be determined; third, there are overfull circular arithmetic operations involved in it. To resolve these problems, a new method to reduce the theoretical solution complications is proposed. By analyzing the operating mechanism of theoretical solution model, redundancies in the theoretical solution can be eliminated, and the ISM mapping with the co-adaptability solution can be set up. Based on this approach, a procedure to solve practical conflicting events in construction projects is established by replacing characteristic variables with mathematic variables. The research results show that the procedure can replace the co-adaptability theoretical solution effectively and solve practical conflicting events in construction projects.

关键词： construction project conflict theoretical solution reduced analysis ISM confirmatory research

Characterization of γ′ precipitates in a nickel base superalloy quenching from aging temperature at different rates

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Rare Metals 2010年第2期29卷 204-208页

作者： LI Hongyu, SONG Xiping, WANG Yanli, and CHEN Guoliang State Key lab for Advanced Metals and Materials, University of Science and Technology beijing, beijing 100083, china State Key lab for Advanced Metals and Materials University of Science and Technology Beijing

The characteristics of γ′ precipitates in a superalloy quenched from 1050°C at different rates were investigated using field emission scanning electron microscope（FESEM）.When quenched from 1050°C, the size of primary aging γ′ precipitates has a small increase in the specimens that experienced iced-brine-quenching, oil-quenching, and air-cooling-quenching conditions and a drastic increase in the specimen that experienced a furnace-cooling-quenching *** cooling γ′ precipitates have unimodal distributions after quenching at the air-cooling rate and bimodal distributions after quenching at the furnace-cooling rate, but there are not these distributions in the specimens that experienced iced-brine-quenching and oil-quenching *** aging at 760°C, the size of primary aging γ′ precipitates appears unaffected in the specimens that experienced iced-brine-quenching, oil-quenching, and air-cooling-quenching ***, it has a drastic increase in the specimen that experienced a furnace-cooling-quenching condition, and it is interesting that the bigger cooling γ′ precipitates have a coalescence and octodendritic *** microhardness study indicates that the hardness has no variation in the specimens that experienced iced-brine-quenching, oil-quenching, and air-cooling-quenching conditions and has a drastic decrease in the specimens that experienced a furnace-cooling-quenching condition and obtains the minimum microhardness value 390.8 HV.

关键词： superalloys precipitates quenching rate microhardness

LLDPE prepared by in situ polymerization using a dual-functional catalytic system of Ti(On-Bu)_4 /AlEt_3-Et(Ind)_2-ZrCl_2/MAO

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Chinese Science Bulletin 2001年第24期46卷 2051-2054页

作者： LIU Zhongyang, XU Demin, GUO Cunyue, WANG Jun, HE Dawei & HU YouliangStale Key lab of Engineering Plastics, Center for Molecular Science, Institute of Chemistry. Chinese Academy of Sciences, beijing 100080, china beijing lab of Catalysis. china National Petroleum Corporation Key lab of Catalysis, beijing 100080, china State Key lab of Engineering Plastics Center for Molecular Science Institute of Chemistry Chinese Academy of Sciences Beijing China beijing lab of Catalysis China National Petroleum Corporation KeyLab of Catalysis Beijing China

Linear low-density polyethylene (LLDPE) was prepared by in situ polymerization using a dual-functional catalytic system containing Et(Ind)2ZrCl2/MAO and Ti(On-Bu)4 /AlEt3 used as co-polymerization catalyst and dimeriza-tion catalyst, respectively. The catalytic system showed high activity and the polymer with low melting point, narrow molecular weight distribution (MWD) and low crystallinity was produced.

关键词： linear low-density polyethylene (LLDPE) in situ poly- merization metallocene.

Preparation, Properties and Characterization of Modified CeO_2/La_2Zr_2O_7 Buffer Layers

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稀有金属材料与工程 2011年第S3期40卷 350-353页

作者： Cheng Yanling, Suo Hongli, Liu Min, Ma Lin, Zhang Teng Key laboratory of Advanced Functional Materials, Ministry of Education, beijing University of Technology, beijing 100124, china beijing Univ Technol Coll Mat Sci & Engn Minist Educ Key Lab Adv Funct Mat Beijing 100124 Peoples R China

The metal organic deposition (MOD) method was used for the epitaxial growth of the CeO2/La2Zr2O7(LZO)/LZO seed layer structure on a cube-textured Ni5W substrate layer by layer. The material phase and the macro-orientations were analyzed by XRD. The surface morphology and the blocking performance of the buffer layer were investigated by SEM and AES. The grain orientation and the crystallographic growth mode of the CeO2 layer were first characterized by electron backscattering diffraction (EBSD). The uniformly distributed islanded LZO seed layer optimized both the in-plan and the out-plan orientation of the CeO2/LZO buffer layers, and the CeO2/LZO buffer layers with a thickness of 175 nm acted as an efficient Ni,W barrier. The EBSD analysis indicated that the crystallographic orientation of each layer can be obtained at various accelerating voltages for the multilayer sample, the percentage of {001} rotated cube texture of CeO2 layer reaching 97.4% at the accelerating voltage of 15 kV, thus showing epitaxial deposition with a high texture.

关键词： coated conductor buffer layer La2Zr2O7 seed layer CeO2 rotated cube texture accelerating voltage

Acid/alkali gated photochromism of two diarylperfluorocyclopentenes

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Science china Chemistry 2007年第5期50卷 581-586页

作者： CHEN ZiHui1, ZHAO ShengMin2, LI ZhongYu1, ZHANG Zhi1 & ZHANG FuShi1 1 The Key lab of Organic Optoelectronics & Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, beijing 100084, china 2 lab of Printing & Packing Materials and Technology-beijing Area Major laboratory, beijing Institute of Graphic Communication, beijing 100084, china The Key lab of Organic Optoelectronics & Molecular Engineering of Ministry of Education Department of Chemistry Tsinghua University Beijing China lab of Printing & Packing Materials and Technology-beijing Area Major laboratory Beijing Institute of Graphic Communication Beijing China

Two novel diarylfuorocyclopentenes, which underwent gated photochromism, were synthesized. It was found that the photochromic property of these diarylethenes could be switched by alternative addition of acids/alkalis,... 详细信息

关键词： photochromism, diarylethene, gated reactivity, pyridinium betaine