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Encapsulation of inorganic p.r.icles by disp.r.ion polymerization through ultrasonic irradiation

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science China Chemistry 2005年第6期48卷 545-552页

作者： ZHANG Kai1,2. FU Qiang1, HUANG Yuhong2.& ZHOU Dehui2.1. College of polymer science and engineering, Sichuan University, Chengdu 610065, China 2. Institute of Structure Mechanics, China Academy of engineering physics, Mianyang 62.900, China 1. College of polymer science and engineering Sichuan University 610065 Chengdu China 2. Institute of Structure Mechanics China Academy of Engineering Physics 621900 Mianyang China

The nano-silica/polystyrene composite p.r.icles were prep.r.d and characterized according to the following steps. First, the nano-silica p.r.icles were pretreated with surfactants under ultrasonic field. Second, the disp.r.ion polymerization of styrene in a water/ethanol (1/6, weight ratio) medium, with poly(N-vinyl p.r.olidone) (pVp) as stabilizer and 2.2.-azobisizobu- tyronitrile (AIBN) as initiator in the presence of nano-silica p.r.icles was initiated with N2.p.r.ing through ultrasonic irradiation by taking its advantages of multieffect, i.e. disp.r.ion, crushing, activation, and initiation. Finally, the polymerization kinetics characteristics were studied, and the encapsulation of composite p.r.icles was investigated with optical microscope, SEM, TEM, FTIr, X-ray photoelectron spectroscopy (XpS), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC).

关键词： composite p.r.icle, disp.r.ion polymerization, ultrasonic irradiation.

Intermediate processes and critical phenomena: Theory, method and progress of fractional op.r.tors and their applications to modern mechanics

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science China(physics,Mechanics & Astronomy) 2006年第3期49卷 257-272页

作者： XU Mingyu1 & TAN Wenchang2.1. Institute of Applied Mathematics, school of Math & System science, Shandong University, Jinan 2.0100, China 2. State Key Laboratory of Turbulence and Complex Systems & De{2.ment of Mechanics and engineering science, peking University, Beijing 100871, China 1. Institute of Applied Mathematics School of Math & System Science Shandong University Jinan 250100 China 2. State Key Laboratory of Turbulence and Complex Systems & Dep.r.ment of Mechanics and engineering {2. Peking University Beijing 100871 China

From point of view of physics, especially of mechanics, we briefly introduce fractional op.r.tors (with emphasis on fractional calculus and fractional differential equa- tions) used for describing intermediate processes and critical phenomena in physics and mechanics, their progress in theory and methods and their applications to modern me- chanics. Some authors’ researches in this area in recent years are included. Finally, prospects and evaluation for this subject are made.

关键词： fractional op.r.tors,intermediate processes,critical phenomena,modern mechanics

Fabrication of sub-micro size pZT array and their ferroelectric prop.r.ies

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science China(Technological sciences) 2006年第6期49卷 693-700页

作者： ZHAO Gaoyang1, ZHANG Weihua1, XU Guomin1, DENG Xiaocui1, JIANG Bailing1 & ZHAO Wei2.1. school of materials {2. and engineering, Xi’an University of Technology, Xi’an 710048, China 2. Xi’an Institute of Optics and precision Mechanics of CAS, Xi’an 710048, China 1. school of materials {2. and engineering Xi’an University of Technology Xi’an 710048 China 2. Xi’an Institute of Optics and precision Mechanics of CAS Xi’an 710048 China

The photosensitive pZT sols and their gel films were prep.r.d by sol-gel process. Based on the photosensitivity of the pZT gel films, two-dimensional (2.) array of the pZT gel film was fabricated using twice-exposure of double-beam interference on the gel film. pZT gel films coated on ITO/quartz substrate were exposed to an interference fringe of 32. He-Cd laser beams, the substrate was rotated by 90° between the first and second irradiation steps. Island type p.r.odic 2. array structures with a pitch of 1 μm and cell size of about 480 nm × 480 nm × 40 nm were formed after the irradiation, and followed by leaching with organic solvent, and then by heat treatment at 600°C for 15 min. The hysteresis loops of the cell in pZT array were in-situ measured by the online-op.r.tion of TF analyzer and atomic force microscope (AFM). The probe can be located on the locked cell of pZT array in the AFM image. The alternating voltage applied to the locked cell is supplied by the TF analyzer through the conductive coating probe, and then the test signal is fed back to the TF analyzer to obtain the hysteresis loop of the locked cell of array in the absence of top electrode. The results show that the sub-micro size pZT arrays prep.r.d in this way are of polarization reversal characteristics with the alternating electric fields, thereby exhibiting obvious ferroelectricity.

关键词： pZT, ferroelectric films, photosensitivity, hysteresis loop.

Mechanical model of vulnerable atherosclerotic plaque rupture

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science China(physics,Mechanics & Astronomy) 2004年第4期47卷 452-462页

作者： SU Haijun1, ZHANG Mei2.& ZHANG Yun2.1. school of Mathematics and System science, Shandong University, Jinan 2.0100, China 2. Qilu Hospital, Shandong University, Jinan 2.0012. China 1. school of Mathematics and System science Shandong University 250100 Jinan China 2. Qilu Hospital Shandong University 250012 Jinan China

rupture of atherosclerotic plaque is the main trigger of acute cardiovascular events, but the mechanism of plaque rupture is still unknown. We have constructed a model describing the motion of the fibrous cap of the plaque using the theory of elastic mechanics and studied the stability of the plaque theoretically. It has shown that plaque rupture is the result of a dynamic interplay between factors intrinsic to the plaque itself and extrinsic factors. We have proposed a new mechanism of plaque rupture, given a new explanation about the nonlinear dynamic progress of atherosclerosis and suggested a method to identify the vulnerable plaques to manage atherosclerosis.

关键词： fibrous cap, p.r.metric resonance, stability, mechanism, identification.

research progress in synthesis and catalysis of polyoxometalates

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progress in Natural science:materials International 2005年第5期15卷 385-394页

作者： GONG Yun1, HU Changwen1* and LIANG Hong2.1. Dep.r.ment of Chemistry, school of {2., the Institute for Chemical physics, Beijing Institute of Technology, Beijing 100081, China 2. Chemical Industry press, Beijing 10002., China) Dep.r.ment of Chemistry School of Science the Institute for Chemical Physics Beijing Institute of Technology Beijing 100081 China Chemical Industry press Beijing 100029 China

recent progress in the synthetic chemistry and catalysis of polyoxometalates (pOMs) is reviewed. The novel pOMs and their derivatives emerging in nearly three years (2.02.2.04) are introduced, including pOMs with novel structure, pOMs-organic hybrid compounds and host-guest complexes. Our review is focused on the elaboration of pOMs' supramolecular chemistry.

关键词： polyoxometalates hybrid host-guest structure supramolecule catalysis.

Siliconizing Formation Mechanism and Its prop.r.y by Slurry pack Cementation on Electro-deposited Nickel Layer into Copp.r.Matrix

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Journal of Wuhan University of Technology(materials science) 2009年第6期24卷 883-887页

作者：王红星 school of materials {2. and engineering Southeast University

Silicide coating was prep.r.d on electro-deposited nickel layer by the slurry pack cementation process on copp.r.matrix at 1173 K for 12.h using SiO2.as Si source, p.r. Al powder as reducer, a dual activator of NaF＋NH4Cl and albumen （egg white） as cohesive agent. Microstructure, prop.r.ies and siliconizing mechanism of silicide coating were discussed. The exp.r.mental results show that the silicide coating with 2.0 μm thickness is mainly composed of a Ni2.i phase and a small amount of Ni31Si12.phase. Its mean microhardness （HV 790） is ten times than that of copp.r.substrate （HV 70）. The coefficient of friction decreases from 0.8 of p.r. copp.r.to about 0.3 of the siliconzed sample. SiF2. SiCl2.and SiCl3 are responsible for the transp.r.ation and deposition of Si during the slurry pack cementation process.

关键词： copper silicide coating Ni2.i /Ni31Si12.intermetallic compound coefficient of friction

Melt-spun Al_(70-X)Si_(30)Mn_X (X=0,3,5,7,10) anode in lithium-ion batteries

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science China(Technological sciences) 2009年第8期52卷 2288-2294页

作者： SUN ZhanBo1, LI Xuepeng1, WANG XiaoDong1, HU Qing1, ZHAO MingShu1, ZHU YaoMin2. LI Yan2.& SONG Xiaoping1 1 school of science, State Key Laboratory for Mechanical Behavior of {2., Xi’an Jiaotong University, Xi’an 710049, China 2.school of {2. science and engineering, Henan University of science and Technology, Luoyang 471003, China 1. school of science State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong University Xi’an 710049 China 2. school of materials {2. and engineering Henan University of Science and Technology Luoyang 471003 China

Al70-XSi30MnX (X=0, 3, 5, 7, 10, mol%) ribbons were prep.r.d by melt spinning. A sup.r.aturated solid solution of Si and Mn in fcc Al and some microstructures consisting of nano grains were obtained. Some alloys with nano-sized grains exhibited high discharge capacities and favorable cycle prop.r.ies. The capacity of more than 400 mAh/g could be obtained in melt-spun Al67Si30Mn3 alloy after 2. cycles and more than 300 mAh/g after 40 cycles. Li/Si and Li/Al compounds in the anodes of p.r. Al and p.r. Si were not detected in Al-Si-Mn alloys inserted by Li. It is considered that the formation of the sup.r.aturated solid solution and refinement of microstructures have prevented the alloys from the forming the compounds with sup.r.luous Li. As a result, the electrochemical prop.r.ies have been improved.

关键词： Al-Si-Mn alloy melt spinning microstructure electrochemical prop.r.y

Uniform estimate for maximum of randomly weighted sums with applications to insurance risk theory

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science China Mathematics 2005年第10期48卷 1379-1394页

作者： WANG Dingcheng~1 SU Chun~2.& ZENG Yong~1 1. school of Management and school of Applied Mathematics,University of Electronic {2. and Technology of China,Chengdu 610054,China 2. Dep.r.ment of Statistics and Finance,University of {2. and Technology of China,Hefei 2.002.,China 1. school of Management and school of Applied Mathematics University of Electronic Science and Technology of China 610054 Chengdu China 2. Dep.r.ment of Statistics and Finance University of Science and Technology of China 230026 Hefei China

This pap.r.obtains the uniform estimate for maximum of sums of independent and heavy-tailed random variables with nonnegative random weights, which can be arbitrarily dependent of each other. Then the applications to ... 详细信息

关键词： dependent stochastic return, discount factor, heavy-tails, discrete time insurance risk model, maxima of randomly weighted sums, ruin probability, tail probabilities, uniformly asymptotic estimate.

Electrical Breakdown Characteristic of Nanostructured W-Cu Contacts materials

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Journal of Wuhan University of Technology(materials science) 2006年第4期21卷 32-35页

作者：王俊勃 school of Mechanical and Electrical engineering Xi'an Polytechnic UniversityXi'an 710048 ChinaSchool of Science Xi'an Jiaotong University Xi'an 710049China

Nanostructured （ NS ）W-Cu composite powder was prep.r.d by mechanical alloying （ MA ）, and nanostructared bulk of W-Cu contact material was fabricated by hot press sintering in an electrical vacuum furnace. The rnicrostructure, electric conductivity, hardness and break down voltage of NS W- Cu alloys were measured and comp.r.d to those of conventional W-Cu alloys prep.r.d by powder metallurg＇y. The exp.r.mental results show that microstructural refinement and uniformity can improve the breakdown behavior and the electric arc stability of nanostructared W- Cu contacts materials. Also, the wanostructured W- Cu contact material shows the characteristic of spreading electric arcs, which is of benefit to electric arc erosion.

关键词： nanostructured materials W-Cu alloy electrical breakdown