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The Coagulation Process of Nascent Fibers in PAN Wet-spinning

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Journal of Wuhan university of Technology(Materials {1.) 2010年第2期25卷 200-205页

作者：陈娟葛曷一 school of Material {1. and Engineering University of Jinan

The evolvement of microstructure and properties of nascent fibers during coagulation process in the polyacrylonitrile （PAN） wet-spinning and the effect of coagulation bath conditions on the structure and properties of the nascent fibers were investigated by the means of X-ray diffraction （XRD）, scanning electron microscope （SEM）, fiber fineness machine, fiber tensile strength machine, etc. The experimental results indicate that the nascent fibers become denser and have fewer inner defects, the diameter of nascent fibers shrink and the crystallization degree of nascent fibers gradually increases with the increasing of coagulation time. Too large spinning tension leads to grooves occurring on surface of fibers. To obtain circular cross-section of nascent fibers the optimal coagulation conditions are 50 ℃, 65% （concentration） and 0.9 （draw ratio）.

关键词： PAN wet-spinning coagulation nascent fibers

Effect of Lanthanum-praseodymium-cerium Mischmetal on Mechanical Properties and Microstructure of Mg-A1.Alloys

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Journal of Wuhan university of Technology(Materials {1.) 2011年第1期26卷 102-104页

作者：易勇 Research Center of Laser Fusion China Academy of Engineering Physics school of Materials {1. & Engineering Southwest University of Science & Technology

The effects of lanthanum-praseodymium-cerium mischmetal （LPC） on the microstructure and mechanical properties of Mg-Al alloy were investigated. With the addition of LPC, an additional rod-like Al1.La3 phase was deposited in the alloy. LPC greatly improves the tensile strength of cast Mg-Al alloys but negatively affects the elongation of cast alloys above 473 K. Cast alloys are strengthened by both precipitation strengthening and dispersion strengthening at ambient temperature. When the temperature exceeds 473 K, only the dispersion operates as a strengthening mechanism.

关键词： lanthanum-praseodymium-cerium mischmetal Mg-alloy microstructure mechanical properties

An interpolating boundary element-free method (IBEFM) for elasticity problems

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science China(Physics,Mechanics & Astronomy) 2010年第4期53卷 758-766页

作者： REN HongPing 1., CHENG YuMin 2 & ZHANG Wu 1.1.school of Computer Engineering and {1., Shanghai university, Shanghai 200072, China 2 Shanghai Institute of Applied mathematics and Mechanics, Shanghai university, Shanghai 200072, China 1. school of Computer Engineering and {1. Shanghai University Shanghai 200072 China2. Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 China

The paper begins by discussing the interpolating moving least-squares (IMLS) method. Then the formulae of the IMLS method obtained by Lancaster are revised. On the basis of the boundary element-free method (BEFM), combining the boundary integral equation method with the IMLS method improved in this paper, the interpolating boundary element-free method (IBEFM) for two-dimensional elasticity problems is presented, and the corresponding formulae of the IBEFM for two-dimensional elasticity problems are obtained. In the IMLS method in this paper, the shape function satisfies the property of Kronecker δ function, and then in the IBEFM the boundary conditions can be applied directly and easily. The IBEFM is a direct meshless boundary integral equation method in which the basic unknown quantity is the real solution to the nodal variables. Thus it gives a greater computational precision. Numerical examples are presented to demonstrate the method.

关键词： moving least-squares (MLS) approximation interpolating moving least-squares (IMLS) method boundary integral equation meshless method boundary element-free method (BEFM) interpolating boundary element-free method (IBEFM) elasticity problem

Relationship between surface subsidence factor and mining depth of strip pillar mining

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中国有色金属学会会刊：英文版 2011年第S3期21卷 594-598页

作者： GUO Wen-bing1. 2, HOU Quan-lin 1. ZOU You-feng2 1. College of Earth science, Graduate {1. of Chinese Academy of sciences, Beijing 1.0049, China 2. school of Energy science and Engineering, Henan Polytechnic {1., Jiaozuo 454000, China Chinese Acad Sci Coll Earth Sci Grad Univ Beijing 100049 Peoples R China Henan Polytech Univ Sch Energy Sci & Engn Jiaozuo 454000 Peoples R China

Strip pillar mining is one of the most important technical measures to control mining subsidence in China. Mining depth is one of the most important factors that can affect the mining subsidence in strip pillar mining. Six numerical simulation models were set up to simulate the surface subsidence of strip pillar mining in different mining depths. The mining depth in these six models ranges from 300 to 800 m. The simulated results were compared and analyzed. The formula was established based on the simulated results. It demonstrated that the subsidence of strip pillar mining method is related to mining depth. While the other conditions are the same, the subsidence of strip pillar mining increases with the increase of mining depth by logarithmic relationship.

关键词： subsidence factor strip pillar mining mining depth numerical simulation

The influence of laser pulse on the photoabsorption spectra of Li atom in strong external field

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science China(Physics,Mechanics & Astronomy) 2006年第2期49卷 178-186页

作者： WANG Dehua1.& LIN Shenglu2 1. school of Physics and Electronic Engineering, Yantai Normal {1., Yantai 264025, China 2. Department of Physics, shandong Normal {1., Jinan 25001., China 1. school of Physics and Electronic Engineering Yantai Normal University Yantai 264025 China 2. Department of Physics Shandong Normal University Jinan 250014 China

Using the time-dependent perturbation theory and the calculation formula of the single- and double-pulse absorption spectra of the atom in strong external fields, we calculate the single- and double-pulse absorption spectra of Li atom in strong magnetic field for different pulse widths. The results show that a pulse of some width can reduce the contribution of the short period closed orbits and eliminate the contribution of the long period orbits. Compared with the single-pulse absorption spectra, we found that for some phase differences, the double-pulse laser absorption spectra are strengthened; while for others, they are reduced. Therefore, we can use the pulse laser to control the oscillation of the absorption spectra and obtain the optimization object.

关键词： laser pulse closed orbit absorption spectra.

Influences of Heat Treatments on Crystallization in SiO_2-Al_2O_3-MgO-K_2O-F Glass-ceramics

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Journal of Wuhan university of Technology(Materials {1.) 2011年第3期26卷 403-406页

作者：田清波 school of Materials {1. and Engineering Shandong Jianzhu University

Five kinds of heating treatment processing were chosen according to the experiment result of differential scanning calorimeter to prepare SiO2-Al2O3-MgO-K2O-F glass ceramics *** effects of heat treatment processing on the crystallization of these samples were explored by X-ray diffraction and scanning electron microscopy *** results indicate that phase separations can occur in the bulk regions of the glass sample when holding at 670 ℃ for 3 *** phase separation can accelerate the precipitation of the crystallization phase： when the temperature directly rises to 950 ℃ after the phase separation,there are mainly interlocked plate-shapes mica phases;If holding at 860 ℃ for 3 h first after the phase separation,the star-shape cordierite phases form;Thereby,elevating temperature to 950 ℃ and holding for 1.h will bring plate-shapes mica phases growing at inter-phases of the star-shape cordierite and finally the homogeneously distributed mica- cordierite composites ***,if heating at 950 ℃ directly without holding at 670 ℃,there is a small quantity of phase separation appearing at 670 ℃ and a little crystallization phases precipitating at last.

关键词： thermal decomposition mechanism kinetics Siderite

Search for B_c (ns) via the B_c (ns) → B_c (ms) π^+ π^- transition at LHCb and Z^0 factory

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science China(Physics,Mechanics & Astronomy) 2010年第11期53卷 2019-2024页

作者： KE HongWei 1.& LI XueQian 2 1.school of {1.,Tianjin university,Tianjin 300072,China 2.school of Physics,Nankai university,Tianjin 300071.China 1. school of {1. Tianjin University Tianjin 300072 China2. School of Physics Nankai University Tianjin 300071 China

It is interesting to study the characteristics of the whole family of B c which contains two different heavy *** and the proposed Z 0 factory provide an opportunity because a large database of the B c family will be achieved.B c and its excited states can be identified via their decay *** suggested by experimentalists,B-c (ns) → B c +γ is not easy to be clearly measured,instead,the trajectories of π + and π- occurring in the decay of B c (ns) → B c (ms) + π + π( n > m ) can be unambiguously identified,thus the measurement seems easier and more reliable;therefore this mode is more favorable at the early running stage of LHCb and the proposed Z 0 *** this work,we calculate the rate of B c (ns) → B c (ms) + π + π-in terms of the QCD multipole-expansion and the numerical results indicate that the experimental measurements with the luminosity of LHC and Z 0 factory are feasible.

关键词： meson hadronic decay QCD multipole-expansion

CMC surfaces in the hyperbolic 3-space

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Chinese science Bulletin 1998年第7期43卷 547-550页

作者： YU Zuhuan 1. 2 and LI Zhenqi 1. 3 1. Institute of mathematics, Fudan {1., Shanghai 200433, China 2. Department of mathematics,Sichuan Union {1., Chengdu 61.064, China 3. Department of mathematics, Nanchang {1., Nanchang 33 nstitute of Mathemalics Fudan University Shanghai China Department of mathematics Sichuan Union University Chengdu China Department of mathematics Nanchang University Nanchang China

CMC-H surfaces satisfying H≥1.are studied. It is proved that these surfaces possess a natural representation which is a generalization of the Bryant’s result.

关键词： hyperbolic space CMC surface Weierstrass representation.

C^MC^N D-computable state

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science China(Physics,Mechanics & Astronomy) 2008年第9期51卷 1300-1307页

作者： LIU DongDong1.2 & DI YaoMin1.1.school of Physics & Electronic Engineering,Xuzhou Normal {1.,Xuzhou 221.1.,China 2.school of mathematics & Physics science,Xuzhou Institute of Technology,Xuzhou 221.08,China 1. school of Physics & Electronic Engineering Xuzhou Normal University Xuzhou 221116 China 2. school of {1. & Physics science Xuzhou Institute of Technology Xuzhou 221008 China

The notions of D-computable state and D-concurrence are generalized to the CMCN system. A class of D-computable state on CMCN is given and the calculating method of the lower bound of D-concurrence is provided. Th... 详细信息

关键词： quantum entanglement entanglement of formation concurrence D-computable state