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NON－EXISTENCE　OF　SINGULAR　CYCLES　IN　A　QUADRIC　DIFFERENTIAL　SYSTEM　WITH　FINE　FOCUS　OF　ORDER　THREE

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Systems Science and Mathematical Sciences 1994年第2期7卷 133-139页

作者： LU Gang LIANG Zhao jun(department of Mathematics, Huazhong Normal Universitg, wuhan 430070, China)

ＮＯＮ－ＥＸＩＳＴＥＮＣＥＯＦＳＩＮＧＵＬＡＲＣＹＣＬＥＳＩＮＡＱＵＡＤＲＩＣＤＩＦＦＥＲＥＮＴＩＡＬＳＹＳＴＥＭＷＩＴＨＦＩＮＥＦＯＣＵＳＯＦＯＲＤＥＲＴＨＲＥＥ￥ＬＵＧａｎｇ；ＬＩＡＮＧＺｈａｏｊｕｎ（Ｄｅｐｏｒ... 详细信息

ＮＯＮ－ＥＸＩＳＴＥＮＣＥＯＦＳＩＮＧＵＬＡＲＣＹＣＬＥＳＩＮＡＱＵＡＤＲＩＣＤＩＦＦＥＲＥＮＴＩＡＬＳＹＳＴＥＭＷＩＴＨＦＩＮＥＦＯＣＵＳＯＦＯＲＤＥＲＴＨＲＥＥ￥ＬＵＧａｎｇ；ＬＩＡＮＧＺｈａｏｊｕｎ（ＤｅｐｏｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃ...

关键词： Homodinic heteroclinic centre-focus criterion singular cycles.

Effect of Molecular Structure on the Performance of Polyacrylic Acid Superplasticizer

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Journal of wuhan University of Technology(Materials Science) 2007年第2期22卷 245-249页

作者：张荣国雷家珩 department of Applied Chemistry Wuhan University of Technology

The effects of structure parameters, such as molecular structure, segment kinds, molecular weight, and organic functional groups, on the performance of polyacrylic acid superplasticizer were discussed. According to the differences of chain sections, functional groups, eic, polyacrylic acid superplasticizer could be divided into A, b, C three parts. Among them, A chain section included sulfonic acid groups, b chain section carboxyl groups, C chain section polyester. Polyacrylic acid superplasticizers with different matching of A, b, C chain sections, different length of C chain section and different molecular weights were synthesized by acrylic acid, polyethylene glycol, sodium methyl allylsulfonate; the relation between the molecular structure and perfolxnance was also studied. The expetimental results indicate that the water-reduction ratio increases obviously with the increment of the proportion of sodium methyl allylsulfonate chain section in the molecular; the slump retention increases greatly with the increment of the proportion of acrylic acid chain section; the dispersion of cement particles increases with the increment of the chain length of polyethylene glycol; when the molecular weight is in the range of 5000, the dispersion and slump retentibity increase with the increment of the average molecular weight of polymers.

关键词： polyacrylic acid superplasticizer cement concrete structure and performance anion surface-active agent molecule structural design

Ferroelectric properties of bi_(3.4)Ho_(0.6)Ti_3O_(12) thin films prepared by sol-gel method

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Science China(Technological Sciences) 2008年第9期51卷 1439-1444页

作者： FU ChengJu1, HUANG ZhiXiong1, LI Jie2 & GUO DongYun3 1 School of Materials Science and Technology, wuhan University of Technology, wuhan 430070, China 2 School of Mechanical Engineering, Chongqing University of Science and Technology, Chongqing 400050, China 3 department of Physics, wuhan University, wuhan 430072, China School of Materials Science and Technology Wuhan University of Technology School of Mechanical Engineering Chongqing University of Science and Technology

We have prepared the Ho-substituted bismuth titanate (bi3.4Ho0.6Ti3O12, bHT) thin films on Pt/Ti/SiO2/Si substrates using sol-gel method. The crystal structure and morphology of the films were characterized using X-ray diffraction and atomic force microscopy. The bHT film shows a single phase of bi-layered Aurivillius structure and dense microstructure. The 2Pr and 2Ec of the 600-nm-thick bHT film were 38.4 μC/cm2 and 376.1 kV/cm, respectively at applied electric field 500 kV/cm. The dielectric constant and dielectric loss are about 310 and 0.015 at a frequency of 1 MHz, respectively. The Pr value decreased to 93% of its pre-fatigue values after 4.46×109 switching cycles at 1 MHz frenquency, and the bHT film shows good in-sulating behavior according to the test of leakage current.

关键词： bi3.4Ho0.6Ti3O12 thin film sol-gel method ferroelectric property fatigue dielectric constant

PROGRESSING WAVE SOLUTIONS TO QUASI-LINEAR SYSTEMS MIXED PRObLEMS

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Chinese Annals of Mathematics,Series b 1994年第4期15卷 401-420页

作者： WANG WEIKE(department of Mathematics,wuhan University,wuhan 430072,China.) 武汉大学数学系湖北武汉 430072

The author studies the technique of paradifferential operator defined on a space of conormaldistribution with three indeces,and then use this technique to prove that a progressing wavewhich hits the boundary is reflec... 详细信息

关键词： Quasi-linear system Mixed problem Conormal distribution Tangential Paradifferential operator Reflection of progressing wave.

UNIQUENESS OF THE POSITIVE SOLUTION FOR SINGULAR NONLINEAR bOUNDARY VALUE PRObLEMS

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Systems Science and Mathematical Sciences 1993年第1期6卷 25-31页

作者： DENG Yinbin CAO Daomin department of Mathematics,Huazhong Normal University, wuhan 430070,China wuhan Institute of Mathematical Sciences, Academia Sinica, wuhan 430071, China

This paper is concerned with the bounded value problems1/p（t）（p（t）u’）’+f（u）=0, t>0, u’（0）=0, lim t→+∞ u（t）=0,where f（0）=0. Such problems arise in the study of semi-linear elliptic differential equa-tions in Rn. It is shown that the problem has at most one positive solution under appro-priate conditions on f and p. Our result can include the important case that p（t）=fn-1and f（u）=uP-u, where n>1, p>1 are some given constants.

关键词： Uniqueness singular boundary value problem semilinear elliptic equation

COMPUTER VISION APPLIEDIN THE PRECISION CONTROL SYSTEM

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Chinese Journal of Mechanical Engineering 2002年第1期15卷 87-89页

作者： Zhang Qingying Logistics Engineering department，wuhan University of Technology，wuhan 430063，China Logistics Engineering Departiment Wuhan University of Technology Wuhan 430063

Computer vision and its application in the precision control system arediscussed. In the process of fabricating, the accuracy of the products should be controlledreasonably and completely. The precision should be kept and adjusted according to the information offeedback got from the measurement on-line or out-line in different procedures. Computer vision isone of the useful methods to do this. Computer vision and the image manipulation are presented, andbased on this, a n-dimensional vector to appraise on precision of machining is given.

关键词： Computer vision Measurement Precision Quality of products

The Eficiency of a Free-electron laser

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光电子·激光 1998年第1期 66-69页

作者： Zhu Jiaqing Liu Yanshen (department of Physics,Central China Normal University,wuhan 430070,China)

ＴｈｅＥｆｉｃｉｅｎｃｙｏｆａＦｒｅ┐ｅｌｅｃｔｒｏｎｌａｓｅｒＺｈｕＪｉａｑｉｎｇＬｉｕＹａｎｓｈｅｎ（ＤｅｐａｒｔｍｅｎｔｏｆＰｈｙｓｉｃｓ，ＣｅｎｔｒａｌＣｈｉｎａＮｏｒｍａｌＵｎｉｖｅｒｓｉｔｙ，Ｗｕｈａｎ... 详细信息

ＴｈｅＥｆｉｃｉｅｎｃｙｏｆａＦｒｅ┐ｅｌｅｃｔｒｏｎｌａｓｅｒＺｈｕＪｉａｑｉｎｇＬｉｕＹａｎｓｈｅｎ（ＤｅｐａｒｔｍｅｎｔｏｆＰｈｙｓｉｃｓ，ＣｅｎｔｒａｌＣｈｉｎａＮｏｒｍａｌＵｎｉｖｅｒｓｉｔｙ，Ｗｕｈａｎ４３００７０，Ｃｈｉｎａ）Ａｂｓｔ...

关键词： free electron laser scattered photon efficiency

FORCE REDUCTION OF FLOW AROUND A SINUSOIDAL WAVY CYLINDER

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Journal of Hydrodynamics 2009年第3期21卷 308-315页

作者： ZOU Lin LIN Yu-feng School of Mechanical and Electronic Engineering Wuhan University of Technology Wuhan 430070 China department of Mechanical Engineering The Hong Kong Polytechnic University Hong Kong China

A large eddy simulation of cross-flow around a sinusoidal wavy cylinder at Re = 3000 was performed and the load cell measurement was introduced for the validation test. The mean flow field and the near wake flow structures were presented and compared with those for a circular cylinder at the same Reynolds number. The mean drag coefficient for the wavy cylinder is smaller than that for a corresponding circular cylinder due to the formation of a longer wake vortex generated by the wavy cylinder. The fluctuating lift coefficient of the wavy cylinder is also greatly reduced. This kind of wavy surface leads to the formation of 3-D free shear layers which are more stable than purely 2-D free shear layers. Such free shear layers only roll up into mature vortices at further downstream position and significantly modify the near wake structures and the pressure distributions around the wavy cylinder. Moreover, the simulations in laminar flow condition were also performed to investigate the effect of Reynolds number on force reduction control.

关键词： wavy cylinder force reduction Large Eddy Simulation (LES) Reynolds number effect

GEOMETRIC　PROPERTIES　OF　A　CLASS　OF　CUbIC　SYSTEM　WITH　AN　INVARIANT　LINE

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Systems Science and Mathematical Sciences 1996年第2期9卷 97-100页

作者： ZHANG Xingan LIANG Zhaojun (department of Mathematics, Central China Normal University, wuhan 430070, China) 华中师范大学数学系湖北武汉

ＧＥＯＭＥＴＲＩＣＰＲＯＰＥＲＴＩＥＳＯＦＡＣＬＡＳＳＯＦＣＵＢＩＣＳＹＳＴＥＭＷＩＴＨＡＮＩＮＶＡＲＩＡＮＴＬＩＮＥＺＨＡＮＧＸｉｎｇａｎ；ＬＩＡＮＧＺｈａｏｊｕｎ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃｓ，... 详细信息

ＧＥＯＭＥＴＲＩＣＰＲＯＰＥＲＴＩＥＳＯＦＡＣＬＡＳＳＯＦＣＵＢＩＣＳＹＳＴＥＭＷＩＴＨＡＮＩＮＶＡＲＩＡＮＴＬＩＮＥＺＨＡＮＧＸｉｎｇａｎ；ＬＩＡＮＧＺｈａｏｊｕｎ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃｓ，ＣｅｎｔｒａｌＣｈｉｎａＮｏｒｍａ...

关键词： Central projective transformation diffeomorphically conjugate topologicallyequivalent.