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Experimental study of dynamic mechanical properties of reactive powder concrete under high-strain-rate impacts

science China(Technological sciences) 2010年第9期53卷 2435-2449页

作者： JU Yang1,2.LIU HongBin1,sHENG GuoHua1,3 & WANG HuiJie1 1 state Key Laboratory of Coal Resources and safe Mining,Beijing Key Laboratory of Fracture and Damage Mechanics of Rocks and Concrete,China university of Mining and Technology,Beijing 100083,China 2.department of {2. and Manufacturing engineering,university of Calgary,2.00 university Drive,AB T2. 1N4,Canada 3 school of Resources and Civil engineering,Northeastern university,shenyang 110004,China 1. state Key Laboratory of Coal Resources and safe Mining Beijing Key Laboratory of Fracture and Damage Mechanics of Rocks and Concrete China University of Mining and Technology Beijing 100083 China2. Department of Mechanical and Manufacturing Engineering University of Calgary 2500 University Drive AB T2N 1N4 Calgary Canada3. School of Resources and Civil Engineering Northeastern University Shenyang 110004 China

The dynamic mechanical properties of reactive powder concrete subjected to compressive impacts with high strain rates ranging from 10 to 1.1×102.s-1 were investigated by means of sHPB (split-Hopkinson-pressure-bar) tests of the cylindrical specimens with five different steel fiber volumetric *** properties of wave stress transmission,failure,strength,and energy consumption of RPC with varied fiber volumes and impact strain rates were *** influences of impact strain rates and fiber volumes on those properties were characterized as *** general forms of the dynamic stress-strain relationships of RPC were modeled based on the experimental *** investigations indicate that for the plain RPC the stress response is greater than the strain response,showing strong brittle *** RPC with a certain volume of fibers sustains higher strain rate impact and exhibits better deformability as compared with the plain *** a constant fiber fraction,the peak compressive strength,corresponding peak strain and the residual strain of the fiber-reinforced RPC rise by varying amounts when the impact strain rate increases,with the residual strain demonstrating the greatest *** the fiber content makes trivial contribution to improving the residual deformability of RPC when the impact strain rate is *** tests also show that the fiber content affects the peak compressive strength and the peak deformability of RPC in a different *** a constant impact strain rate and the fiber fraction less than 1.75%,the peak compressive strength rises with an increasing fiber *** peak compressive strength tends to decrease as the fiber volume exceeds 1.75%.The corresponding peak strain,however,incessantly rises with the increasing fiber *** total energy Edisp that RPC consumed during the period from the beginning of impacts to the time of residual strains elevates with the fiber volume increment as long as the fiber fraction

关键词： impact reactive powder concrete (RPC) high strain rate dynamic strength energy consumption dynamic stress-strain response

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synthesis and crystal structure of complex of Ce(NO_3)_3 with N-(3-methyl-pyridin-2.yl)-formimidoyl-(3-methyl-pyridin-2.yl) hydrazone

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science China Chemistry 2004年第3期47卷 251-256页

作者： JIANG Yinzhi1,2.& HU Weixiao1 1. department of Pharmaceutical science, Zhejiang university of Technology, Hangzhou 310032. China 2. department of Applied Chemistry, Zhejiang Institute of science and Technology, Hangzhou 310033, China 1. department of Pharmaceutical science Zhejiang University of Technology 310032 Hangzhou China 2. department of Applied Chemistry Zhejiang Institute of Science and Technology 310033 Hangzhou China

The reaction of 3,6-di-(3-methyl-pyridin-2.yI)-s-tetrazine (DMPTZ, II) with CeIII salt [Ce(NO3)3 · 6H2.] generates a new ligand, N-(3-methyl-pyridin-2.yl)-formimidoyl-(3-methyl-pyridin-2.yl) hydrazone (L), and forms a new complex: a mononuclear complex [Ce(L)(NO3)2.(H2.)3] · NO3 (III). Crystal data for III: space group P-1, with a = 0.7133(4) nm, b = 1.1139(2. nm, c = 1.4572.3) nm, α= 102.13(2.°, β= 99.81(3)°, γ= 91.10(3)°, Z = 2. V = 1113.6(7) nm3, μ = 2.12. mm?1 and F(000) = 630. L acts as a tri-dentate chelating ligand in III. There are 10 coordination sites around Ce3+ of III, which are respectively occupied by seven oxygen atoms (four from two nitrate anions and three from three H2. molecules) and three nitrogen atoms (all from L). The cerium atom and three chelating nitrogen atoms are coplanar. The mechanism of the metal assisted decomposition is discussed briefly.

关键词： rare earth, complex, crystal structure, synthesize, 3,6-bis (3-methyl-pyridin-2.yl)-s-tetrazine, N-(3-methyl-pyridin- 2.yl)-formimidoyl-(3-methyl-pyridin-2.yl) hydrazone.

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A novel DNA computing model based on RecA-mediated triple-stranded DNA structure

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Progress in Natural science:Materials International 2007年第6期17卷 708-711页

作者： Fang Gang1, Zhang shemin2. Dong Yafei1 and Xu Jin1(1. The Key Laboratory of Image Processing and Intelligent Control, department of Control science & engineering, Huazhong {2. of science and Technology, Wuhan 430074, China 2. shaanxi {2. of Technology, Hanzhong 72.000, China) [a]The Key Laboratory of Image Processing and Intelligent Control Department of Control Science & Engineering Huazhong University of Science and Technology Wuhan China [b]shaanxi university of Technology Hanzhong China

The field of DNA computing emerged in 1994 after Adleman’s paper was published. Henceforth,a few scholars solved some noted NP-complete problems in this way. And all these methods of DNA computing are based on conventional Watson-Crick hydrogen bond of doublehelical DNA molecule. In this paper, we show that the triple-stranded DNA structure mediated by RecA protein can be used for solving computational problems. sequence-specific recognition of double-stranded DNA by oligonucleotide-directed triple helix (triplex) formation is used to carry out the algorithm. We present procedure for the 3-vertex-colorability problems. In our proposed procedure, it is suggested that it is possible to solve more complicated problems with more variables by this model.

关键词： DNA computing 3-vertex-colorability problem.

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Reverse reconciliation for continuous variable quantum key distribution

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science China(Physics,Mechanics & Astronomy) 2010年第1期53卷 100-105页

作者： LU ZhiXin 1,2., YU Li 1,2., LI Kang 1,2., LIU BingCan 1,2.3 , LIN JianGui 1,2., JIAO RongZhen 1,2.& YANG BoJun 1,2. school of science, Beijing university of Posts and Telecommunications, Beijing 100876, China 2.Key Laboratory of Information Photonics and Optical Communication, Ministry of Education, Beijing university of Posts and Telecommunications, Beijing 100876, China 3 {2. of Fundamental Courses, Academy of Armored Force engineering, Beijing 100072. China 1. school of science Beijing University of Posts and Telecommunications Beijing 100876 China2. Key Laboratory of Information Photonics and Optical Communication Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China3. Department of Fundamental Courses Academy of Armored Force Engineering Beijing 100072 China

An efficient and practical post-processing technique based on reverse reconciliation for continuous variable quantum key distribution is proposed and simulated with low-density parity check (LDPC) codes. MultiLevel Coding/ Multistage Decoding, which fully utilizes optimization technique such as vector quantization and iterative decoding and the optimal channel coding most close to the shannon limit, was used to realize efficient reverse reconciliation algorithm. simulation results showed that the proposed method can improve the secure key distribution rate to 2.2.kb/s and the coding efficiency to 0.89 over 2. km in single-mode optical fiber. Moreover, there still is room for much improvement.

关键词： quantum communication key distribution reverses reconciliation low-density parity check codes

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mechanical behavior of a shelter system based on cable-strut structures

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Journal of Zhejiang university-science A(Applied Physics & engineering) 2012年第12期13卷 895-903页

作者： Jian-guo CAI1,2.Ya ZHOU1,Jian FENG1,2.Yi-xiang XU3 (1Key Laboratory of C&PC structures of Ministry of Education,southeast university,Nanjing 2.0096,China) (2.ational Prestress engineering Research Center,southeast university,Nanjing 2.0096,China) (3department of Civil engineering,strathclyde university,Glasgow,uk) 1. Key Laboratory of C&PC structures of Ministry of Education Southeast University Nanjing 210096 China 2. National Prestress engineering Research Center Southeast University Nanjing 210096 China 3. department of Civil engineering Strathclyde University Glasgow UK

A shelter system based on cable-strut structures,consisting of compressive struts and high-tensile elements,is described in this *** deployment of the shelter is achieved by tightening inclined *** cables are used to terminate the *** state of self-stress of the cable-strut structures in the fully deployed configuration is given,and the minimum strut length and the maximum load design of the shelter are *** mechanical behavior of the system was studied under symmetrical and asymmetrical load *** results show that the shelter in the deployed configuration satisfies the ultimate limit and the serviceability limit state ***,the stability of the cable-strut system is investigated,considering the effect of imperfections on the buckling of the *** conclude that the influence of imperfections based on the consistent imperfection mode method is not significant.

关键词： Foldable structures Cable-strut structures mechanical behavior self-stress stability

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Effects of crystallization fractions on mechanical properties of Zr-based metallic glass matrix composites

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science China(Physics,Mechanics & Astronomy) 2010年第3期53卷 424-429页

作者： QIU shengBao1,2. YAO KeFu1 & GONG Pan1 1 KLAMPT, department of mechanical {2., Tsinghua university, Beijing 100084, China 2.Institute of Industry Technology, Guangzhou & Chinese Academy of sciences, Guangzhou 511458, China 1. KLAMPT Department of Mechanical Engineering Tsinghua University Beijing 100084 China2. Institute of Industry Technology Guangzhou & Chinese Academy of Sciences Guangzhou 511458 China

The Zr41Ti14Cu12.5Ni10Be2..5 (at.%) bulk metallic glass composites with various crystallization fractions were prepared by pretreating the bulk metallic glassy samples with pulsing current, and then by isothermal annealing at near initial crystallization temperature for different periods of time. The precipitations and crystallization fractions were studied by X-ray diffraction (XRD) and differential scanning calorimetry (DsC), and their effects on mechanical properties of the composite were studied by microhardness, uniaxial compression test and scanning electron microscopy (sEM). The experimental results show that the primary precipitate is quasicrystalline phase and other metastable phases including Be2.r, Zr2.u and FCC would precipitate subsequently. In the initial crystallization process, in which the crystallization fraction increases from 0 to 8.2., both fracture strength and plastic strain increase, with the maximum plastic strain up to 6.4%. When the crystallization fraction is larger than 8.2., the fracture strength and the plastic strain decrease sharply. Furthermore, the alloy with low crystallization fraction is fractured by shearing, while for high crystallization fraction it is fractured by splitting and cleavage. The results show that the mechanical properties of the glassy alloy could be optimized by controlling the processing parameters.

关键词： bulk metallic glass pulsing current crystallization fraction plasticity shear band

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Modeling and simulation of Heat Transfer in Loaded Continuous Heat Treatment Furnace

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材料热处理学报 2004年第5B期25卷 764-768页

作者： KANGJin-wu HUANGTian-you PURUsHOTHAMANRadhakrishnan departmentofmechanical{2. TsinghuaUniversityBeijingChina CHTE WorcesterPolytechnicInstituteWorcesterMA01609USA

Continuous furnaces are widely used in the heat treatment of mass-produced parts. However, the heating up process of parts in continuous furnace is still decided by experience. In this paper the heat transfer in the continuous furnace is formulated firstly. The heat balance in each zone is discussed and equations are given. Coupled with the model for heat transfer between workpieces and furnace and the heat transfer in the workload as well presented in the former developed CHT-6/ for batch furnaces, a program CHT- for continuous furnaces was developed. The model deals with two typical movements of parts: continuous or step by step. The moving speed of parts and load pattern can be optimized based on the calculated temperature distributions and curves, especially, the fastest heated and slowest-heated temperature-distance profiles. A case study is carried out for the heat treatment of a kind of hook-shaped part. The calculated results are analyzed and in good agreement with the measured ones.

关键词：热处理传热连续加热炉建模热平衡

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Nonsingularity in second-order cone programming via the smoothing metric projector

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science China Mathematics 2010年第4期53卷 1025-1038页

作者： WANG Yun 1,& ZHANG LiWei 2.1 College of Information sciences and engineering,shandong Agricultural university,Tai’an 2.1018,China {2. of Applied Mathematics,Dalian university of Technology,Dalian 11602.,China 1. College of Information sciences and engineering Shandong Agricultural University Tai’an 271018 China2. Department of Applied Mathematics Dalian University of Technology Dalian 116024 China

Based on the differential properties of the smoothing metric projector onto the second-order cone,we prove that,for a locally optimal solution to a nonlinear second-order cone programming problem,the nonsingularity of the Clarke's generalized Jacobian of the smoothing Karush-Kuhn-Tucker system,constructed by the smoothing metric projector,is equivalent to the strong second-order sufficient condition and constraint nondegeneracy,which is in turn equivalent to the strong regularity of the Karush-Kuhn-Tucker ***,this nonsingularity property guarantees the quadratic convergence of the corresponding smoothing Newton method for solving a Karush-Kuhn-Tucker ***,the analysis does not need the strict complementarity condition.

关键词： second-order cone programming problem smoothing metric projector B-subdifferential Clarke’s generalized Jacobian smoothing Newton method

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singular Value Decomposition based on AR Model of Quasiperiodic signal

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systems science and systems engineering 2000年第3期10卷 346-351页

作者： DU Zheng\|chun 1,\ YAO Zhen\|qiang 1,\ YAN Jing\|ping 2.1.department of mechanical {2., shanghai Jiaotong university, shanghai 2.0030 2.department of mechanical engineering, southeast university, Nanjing 2.0096, China

By using the singular Value Decomposition (sVD), a Modified AR modeling method based on the principle of sVD is proposed for describing the quasiperiodic signals. The excellent ability of modeling and prediction of th... 详细信息

关键词： singular value decompostion (sVD) AR model prediction

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study on Theory and Application of the Energy Method used for Analyzing Compressive Instability in sheet Forming

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厦门大学学报（自然科学版） 2002年第S1期41卷 126-127页

作者： XIONG Zhi-qing 1, XIE Lan-sheng 2.(1. department of mechanical {2., Nanjing Institute of Techno logy, Nanjing 2.0013, China 2. College of mechanical and Electrical {2., Nanjing university of Aer onautics and Astronautics, Nanjing 2.0016, China)

It is pointed out that there was serious weakness w he n using the energy method for studying compressive plastic instability in sheet forming in the past. Where applying the deduced instability strengths to relativ e engineering analysis, theoretical solutions were away from practices. Its basi c reason is that simplified process in mathematical analysis of elastic bending energy was completely applied to that of plastic bending energy. Where the cambe r expressed by function of displacement normal to a plate was approximated to re alistic deflective camber, the displacement of deflected plate to compressed dir ection was neglected. With the aid of the improved instability strengths, the pr edictions on both critical buckling dimension of blank in cup deep-drawing with out blankholder through cylindrical die or conical die and the minimum blankhold er pressure to prevent buckling under constant load are universally in agreement with both experimental results and experiential data. On the bases of above-mentioned improvement, the approximate expressions for bo th the curvature and the twist used in equation of the energy of elastic bending are also ameliorated. Thus the obtained general equations for both the energy a nd the work done by internal force in plastic bending of a plate are more precis e than before. In the analyses of plastic buckling of shell with bending moment, the effect of bending moment is considered through the work done by simulative bending for ce. The method proposed in this paper can not only simplify analyses but also ge t practical result.

关键词： sheet forming deep-drawing buckling energy me thod

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