检索结果-南通市图书馆

science china(Physics,Mechanics & Astronomy) 2005年第5期48卷 541-548页

作者： GUO Huiping1, LIU Xueguan1,2. YIN Hongcheng2. CHAO Zengming2.& HUANG Peikang2.1. school of Electronics and Information engineering, Soochow University, Suzhou 2.502.,{2. 2. National Electromagnetic Scattering Laboratory, Beijing 100854,{2. 1. school of Electronics and Information engineering Soochow University 215021 Suzhou China 2. National Electromagnetic Scattering Laboratory 100854 Beijing China

The study of constraints on the constitutive relationships of electromagnetic media is of great importance in the aspects of the medium characteristics analysis, the new article material synthesis and the medium parameters reconstruction, etc. According to the fact that the constitutive relationships should not conflict with the general physical laws, the constraints that the constitutive relationships of electromagnetic medium must satisfy have been summarized in this paper. These constraints include determinacy principle, objectivity principle, causality principle and permission principle. And the parameter constraints of the arbitrary linear homogenous time-invariant medium are obtained following the minimum energy consumption principle. This work provides a new way of ascertaining the constitutive relationships of the electromagnetic medium.

关键词： electromagnetic medium, medium parameter constraint, generally acknowledged truths, energy conservation principle, minimum energy consumption principle.

VIBRATION AND CONTROL IN RING ROLLING PROCESS

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中国有色金属学会会刊：英文版 1999年第2期9卷 9-13页

作者： Hua Lin1, 2. Mei Xuesong2.and Wu Xutang2.1 school of Materials science and {2.,Wuhan Automotive polytechnic University, Wuhan 430070, P. R. china2.school of Mechanical {2.,Xian Jiaotong University, Xian 710049, P. R. china 武汉汽车工业大学材料科学与工程学院湖北武汉西安交通大学机械工程学院陕西西安

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关键词： ring rollingvibrationstabilityprocess control

Effect of Pozzolanic Reaction Products on Alkali-silica Reaction

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Journal of Wuhan University of Technology(Materials science) 2006年第3期21卷 168-171页

作者：魏风艳 Shanghai K. Wah Concrete Co.Ltd Shanghai 200030China

The effect of fly ash on controlling alkail-silica rection （ASR） in simudated alkali solution was studied. The expausion of mortar bars and the content of Ca（ OH）2.in cement paste cured at 80 °G for 91 d were measured. Traasmission electron microscopy （TEM） and high-resolution transmission electron microscot9 （HRTEM） were employed to study the microstructure of C-S-H. TEM/ energy dispersive spectroscopy （EDS） leas then used to determine the composition of C-S-H. The pore structure of the paste was analyzed by mercury intntsion porosimetry （MIP）. The results show that the contents of fly ash of 30% and 45% can well inhibit ASR. And the content of Ca（OH） 2.decreases with the increase of fly ash. That fly ash reacted with Ca（OH）2.to produce C-S-H with a low Ca/Si molar ratio could bind more Na^＋ and K^＋ ious, and produce a reduction in the amount of soluble alkali available for ASR. At the same time, the C- S- H produced by pozzolanic reaction converted large pores to snudler ones （ gel pores smaller than 10 nm ） to deusify the pore structure. Perhaps that could inhibit alkali trausport to aggregate for ASR.

关键词： alkali Ca/ Si molar ratio C-S-H alkali-silica reaction

The double reflection on the interface of uniaxial crystals in the Savart polariscope

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science china(Physics,Mechanics & Astronomy) 2009年第7期52卷 1003-1006页

作者： WU JunFang1,2.& ZHANG ChunMin1 1 school of science, Xi’an Jiaotong University, Xi’an 710049,{2. 2.school of science, Xi’an polytechnic University, Xi’an 710048,{2. school of science Xi’an Jiaotong University Xi’an 710049 China school of science Xi’an Polytechnic University Xi’an 710048 China

The reflection in the Savart polariscope is different from the isotropic medium. The double reflection of rays in the Savart polariscope is analyzed and discussed on the basis of the Snell law. The double reflection formulae of the extraordinary ray and the ordinary ray are given. These results may provide a theoretical and practical guide for studying, developing and engineering polarization interference imaging spectrometers.

关键词： the Savart polariscope double reflection the Snell law extraordinary ray ordinary ray

Strength and damage of marble in ductile failure

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Journal of Rock Mechanics and Geotechnical engineering 2011年第2期3卷 161-166页

作者： Mingqing You school of energy {2. and engineering, henan polytechnic University, jiaozuo, 454010, china school of energy {2. and engineering Henan Polytechnic University Jiaozuo 454010 China

To study the effects of loading paths and stress states on rock strength and deformation, marble specimens were axially compressed to various displacements under a confining pressure (CP) firstly, and then the damaged specimens were recompressed under another CP. The bearing capacity of a marble specimen depends merely on CP at the stage of ductile deformation, and it has no relation with the loading history when CP keeps constant or increases. However, the damaged specimen turns into brittle when it is recompressed uniaxially or at a lower CP, and the Young’s modulus and strength are lower than those of a dense specimen. The increasing ratio of triaxial strength to CP has a close relation with the areas of fissures in the damaged specimens but not the internal friction angle. Material strength and bearing capacity are two different conceptions for rocks. Material strength decreases continually as the plastic deformation increases; however, the bearing capacity is determined by both the stress state and the material strength.

关键词： rock mechanics brittle-ductile damage strength Young’s modulus

Degradation of Pore Structure and Microstructures in Hardened Cement Paste Subjected to Flexural Loading and Wet-dry Cycles in Sea Water

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Journal of Wuhan University of Technology(Materials science) 2009年第6期24卷 940-944页

作者：张武满 school of Transportation science and {2. Beihang University Jiangsu Key Laboratory of Construction Materials Southeast University

Hardened cement paste was subjected to the flexural loading and wet-dry cycles in sea water. The degradation of microstructures was obtained using scanning electron microscope （SEM）, and the energy dispersive spectrum （EDS） analysis was carried to analyze the local composition. Mercury intrusion porosimetry （Poremaster GT-60） was used to analyze the degradation of pore structures. The experimental results show that the synergistic action of the flexural loading, wet-dry cycles and sea water leads to significant deterioration of hardened cement paste. The degradation of microstructures in the tensile region is more serious than that in the compressive region. The flexural loading and wet-dry cycles accelerate the chemical attack of sea water.

关键词： hardened cement paste pore structure microstructures flexural loading wet-dry cycles sea water

Interfacial Microstructure and Properties of Ti(C, N)/Ni Bonded by Transient Liquid-phase Diffusion

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Journal of Wuhan University of Technology(Materials science) 2009年第3期24卷 432-439页

作者：周世权熊惟皓 school of Mechanical science and {2. Huazhong University of Science and Technology Department of Mechanical engineering University of Waterloo school of Materials science and {2. Huazhong University of Science and Technology

Effects of the main process parameters（temperature and time） on microstructure and properties of Ti（C, N）/Ni interface bonded by （Cu＋Nb） interlayer in a vacuum diffusion bonding device were investigated. The interfacial microstructures consisted initially of Ni3Nb metallic compound and eutectic of Ni3Nb ＋ CuNiss, and finally transformed to （Ti, Nb）（C, N）＋Ni3Nb near Ti （C, N） and NiCuss ＋ Ni3Nb near Ni when diffusion bonding temperature was 1 52.-1 573 K. It was clear that Cu was a constituent in the transient liquid phase （TLP） into which Ni was dissolved by forming Cu-Ni transition liquid. Nb was dissolved in Cu-Ni transition liquid rapidly. Ti （C, N） conld be wetted by resultant Ni-Nb-Cu transient liquid phase which was followed by a little （Ti, Nb）（C, N） solid solution formed at interface. This increased the interface combining capability. Ultimately the interface shear strength was able to reach 140 MPa. The theoretle analysis and experimental results show that the growth of interfacial reaction layer Ni3Nb accords with parabola law, and the activation energy of diffusion reaction is 115.0±0.5 kJ/mol, while the diffusion reaction speed constant is 12.53 mm/s^1/2.

关键词： vacuum diffusion bonding transient liquid phase (TLP) diffusion bonding interlayer activation energy

Numerical simulation of ski-jump jet motion using lattice Boltzmann method

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science china(Technological sciences) 2011年第S1期54卷 72-75页

作者： ZHANG Hua 1 &ZHANG XiaoDong 2.1 school of Renewable energy,North{2. Electric Power University,Beijing 102.06,china 2.school of energy Power and Mechanical engineering,North{2. Electric Power University,Beijing 102.06,china 1. school of Renewable energy North China Electric Power University Beijing 102206 China 2. school of energy Power and Mechanical {2. North China Electric Power University Beijing 102206 China

Based on the lattice Boltzmann method,a lattice Boltzmann(LB) model of the ski-jump jet two-phase flow is developed first and the corresponding boundary conditions are studied.A simple case study of a droplet horizontal movement calculation is carried out to test and verify the model,where level set method is used to track and reconstruct the moving droplet free surface. Then,we numerically simulate a two dimensional flow field of the ski-jump jet with the LB model,derive the moving surface and velocity vector field of the jet *** simulation results are very consistent with the physical *** effectiveness and reliability of the model are demonstrated by the numerical examples.

关键词： ski-jump jet droplet lattice Boltzmann method interface numerical simulation

A new principle of synthetic cascade utilization of chemical energy and physical energy

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science china(Technological sciences) 2005年第2期48卷 163-179页

作者： JIN Hongguang1, HONG Hui1,2. WANG Baoqun1,2. HAN Wei1,2.& LIN Rumou1,2.1. Institute of engineering Thermophysics, Chinese Academy of sciences, Beijing 100080,{2. 2. Graduate school of the Chinese Academy of sciences, Beijing 100039,{2. 1. Institute of engineering Thermophysics Chinese Academy of Sciences 100080 Beijing China 2. Graduate school of the Chinese Academy of sciences 100039 Beijing China

We propose a new principle of the cascade utilization of both chemical energy and physical energy in energy systems with the integration of chemical processes and thermal cycles. Particularly, a general equation of energy levels of substance, Gibbs free energy of chemical reaction and physical energy is explicitly founded. On the basis of this equation, a chemical-looping combustion and an indirect combustion are investigated. Furthermore, a mechanism of energy release, with the combination of decreasing the energy level of Gibbs free energy and upgrading the energy level of low or middle- temperature thermal energy, is clarified. The promising results obtained here establish a theoretical basis for the further investigation of multi-function systems in which energy and the environment are compatible, and create a new approach to improve the performance of traditional thermal cycles.

关键词： chemical energy, cascade utilization, exergy, energy conversion.

New Receiving Mode of Extinction for Determining Particle Size and Density without Convex Lens

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Chinese Journal of Lasers 2002年第1期11卷 46-51页

作者： WU Weiliang CHEN Hanping (school of Power and energy {2., Shanghai Jiao Tong University, Shanghai 2.0030, china) CAI Xiaoshu WANG Naining (school of Power and energy {2., University of Shanghai for science and Technology, Shanghai 2 school of Power and energy {2. Shanghai Jiao Tong University 上海 200030 school of Power and energy {2. University of Shanghai for Science and Technology 上海 200093

In this article a new receiving mode for scattering light by particle is theoretically discussed. Using this receiving mode the convex lens can be omitted during determining the extinction of particle. Therefore the extinction coefficient of sphere particles is redefined by extrapolating the conventional one. In terms of the calculation results of light scattering the definition of near-field extinction coefficient of a swarm particle is depicted. Through the error analysis it is proved that the error coming from the new definition of extinction coefficient is acceptable for engineering application. In addition, a technique for determining the particle size and density is presented in this article and the advantage using this receiving mode is described.

关键词： extinction of particle light scattering fluctuation method particle size particle density