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含能材料 2001年第1期9卷 8-9页

作者： HU Rong zu 1, YANG De suo 2. ZHANG Jiao qiang 3 (1. department of Chemistry,Northwest University, Xi′an 710065, china 2. department of Chemistry and Chemical Engineering, Baoji College of Arts and Science, Baoji 72.007, china 3. department of 西北大学陕西西安 710065 宝鸡文理学院陕西 721007 西北工业大学陕西西安 710072

Two relationships are established using the least squares method,between the kinetic parameters (the apparent activation energy and pre exponential constant),and the exothermic decomposition temperature and ther... 详细信息

关键词： critical temperature of thermal explosion decomposition temperature DSC energetic materials.

A Feedback-Based Web Search Engine

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Wuhan University Journal of Natural Sciences 2004年第5期9卷 561-568页

作者： ZHANG Wei-feng 1,2.3 , XU Bao-wen 2.3,4., ZHOU Xiao-yu 2.3,4.1. department of Computer Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing 2.0003, Jiangsu, china 2. department of Computer Science and Engineering, Southeast University, Nanjing 2.0096, Jiangsu, china 3. Jiangsu Institute of Software Quality, Nanjing 2.0096 Jiangsu, china 4. The State Key Laboratory of Software Engineering, Wuhan University, Wuhan 4.0072. Hubei, china department of Computer Science and Engineering Nanjing University of Posts and Telecommunications Nanjing Jiangsu China department of Computer Science and Engineering Southeast University Najing Jiangsu China Jiangsu Institute of Software Quality Nanjing Jiangsu China The State Key Laboratory of Software Engineering Wuhan University Wuhan Hubei China

Web search engines are very useful information service tools in the Internet. The current web search engines produce search results relating to the search terms and the actual information collected by them. Since the selections of the search results cannot affect the future ones, they may not cover most people’s interests. In this paper, feedback information produced by the user’s accessing lists will be represented by the rough set and can reconstruct the query string and influence the search results. And thus the search engines can provide self-adaptability. Key words WWW - search engine - query reconstruction - feedback CLC number TP 311. 135.4.Foundation item: Supported by the National Natural Science Fundation of china (60373066). National Grand Fundamental Research 973 Program of china (2.02.B312.0). Opening Foundation of State Key Laboratory of Software Engineering in Wuhan University, Opening Foundation of Jiangsu Key Laboratory of Computer Information Processing Technology in Soochow UniversityBiography: ZHANG Wei-feng (1975-), male, Ph.D. research direction: artificial intelligence, search engine, data mining, network language.

关键词： WWW search engine query reconstruction feedback

Friction-reducing and antiwear behavior of metal halide-stabilized linear phosphazene derivatives as lubricants for a steel-on-steel contact

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Science china(Technological Sciences) 2005年第3期48卷 282-291页

作者： ZHU Jiamei 1,2., LIU Weimin 2.& LIANG Yongmin 2.1. School of Chemical Engineering and Technology, china University of Mining and Technology, Xuzhou 2.1008, china 2. State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical {2., Chinese Academy of Sciences, Lanzhou 730000, china School of Chemical Engineering and Technology China University of Mining and Technology Xuzhou China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou China

A series of novel metal halide-stabilized linear phosphazene derivatives were synthesized. The friction-reducing and antiwear abilities of the resulting products as the lubricants for a steel-on-steel contact were comparatively investigated on an Optimol SRV oscillating friction and wear tester. The morphology of the worn steel surface was observed on a scanning electron microscope, while the chemical states of some typical elements on the worn steel surface were examined by means of X-ray photoelectron spectroscopy. It was found that both the side branch structures and central metals influenced the friction-reducing and antiwear behaviors of the synthetic derivatives as the lubricants, which was related to the different adsorption activities of the organic compounds composed of different organic ingredients and metallic ions on a nascent metal surface. All the synthetic lubricants except for the iron (III) derivative showed increased antiwear abilities with increasing metallic ionic radius. A protective layer originated from the tribochemical reaction together with the adsorbed boundary lubricating layer containing organic fluorine compounds, nitrogen oxide, and Fe 3 (PO 4.) 2.plays an important role in improving the friction and wear behavior of the steel-on-steel system.

关键词： metal halide-stabilized linear phosphazene derivatives,lubricant,steel,tribological properties.

A new orthogonality relationship for orthotropic thin plate theory and its variational principle

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Science china(physics,Mechanics & Astronomy) 2005年第3期48卷 371-380页

作者： LUO Jianhui 1 , LONG Yuqiu 2.& LIU Guangdong 1 1. College of Civil Engineering, Hunan University, Changsha 4.0082. china 2. {4. of Civil Engineering, Tsinghua University, Beijing 100084. china College of Civil Engineering Hunan University Changsha China department of Civil Engineering Tsinghua University Beijing China

The thought how dual vectors are constructed in a new orthogonality relationship for theory of elasticity is generalized into orthotropic thin plate bending problems by using the analogy theory between plane elasticity problems and plate bending problems. Dual differential equations are directly obtained by using a mixed variables method. A dual differential matrix to be derived possesses a peculiarity of which principal diagonal sub-matrixes are zero matrixes. Two independently and symmetrically orthogonality sub-relationships are discovered. By using the integral form for elastic bending theory of orthotropic thin plate the orthogonality relationship is demonstrated. By selecting felicitous dual vectors a new orthogonality relationship for theory of elasticity can be generalized into elastic bending theory of orthotropic thin plate. By using the integral form a variational principle which is relative to differential form and a whole function expression are proposed.

关键词： theory of elasticity, thin plate theory, dual vectors, orthogonality relationship, orthotropic, variational principle.

Properties and applications of cold supersonic gas jet

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Science china(physics,Mechanics & Astronomy) 2006年第6期49卷 709-715页

作者： ZHANG Shaofeng1,2.MA Xinwen1,2.LIU Huiping2.LI Bin1,2.& ZHU Xiaolong1,2.1. Institute of Modern physics,Chinese Academy of Sciences,Lanzhou 730000,china 2. Graduate University of Chinese Academy of Sciences,Beijing 10004.,china Institute of Modern physics Chinese Academy of Sciences Lanzhou China Graduate University of Chinese Academy of Sciences Beijing China

By analyzing the formation mechanism of a supersonic gas jet,a set of equations which describe the atomic beam properties were established. The influence of initial temperature,initial pressure,background gas pressure and pumping speed was discussed in detail. A simulation program was developed based on the equations,and the results under different initial conditions were obtained. The results are in good agreement with the experimental data,and suggest that,in order to get much smaller transverse momentum in collision experiments,it is necessary to lower the initial temperature and the initial pressure of the supersonic gas jet,together with increasing the pumping speed. These results are very instructive for construction of a new generation of cold supersonic gas jets.

关键词： cold supersonic gas jet,zone of silence,nozzle,skimmer.

The optical near-field speckles and their first order statistics on the basis of the integral equations of electromagnetic field

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Science china(physics,Mechanics & Astronomy) 2004年第3期47卷 365-380页

作者： CHENG Chuanfu1, 2. SONG Hongsheng2. LIU Chunxiang2. REN Xiaorong2. ZHANG Ningyu3, TENG Shuyun1 & XU Zhizhan1 1. Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P. O. Box 800-2.1, Shanghai 2.1800, china 2. department of {2., Shandong Normal University, Jinan 2.0014. china 3. Shandong Institute of Architecture and Engineering, Jinan 2.0014. china Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghaichina department of physicsShandong Normal UniversityJinan{2. Shandong Institute of Architecture and EngineeringJinanchina

From Helmholtz equation of the harmonic electromagnetic waves, the integral equations of the light field at the medium boundaries are obtained by use of the Green's theorem and are discretized into linear equation set with the values of the light field and its derivative as the unknowns. On solving the linear equation set, we realize the rigorous computations of the light fields at the boundaries. Then the intensities of the light waves scattered by the random self-affine fractal surfaces in the optical near-field are calculated, and the propagation characteristics, the evolutions of the contrast and the intensity probability density function of the near-field speckles are studied in detail. The near-field speckles are much different from the conventional speckles in the diffraction regions and in the imaging systems. There are obvious local fluctuations in the intensity distributions of the near-field speckles and such fluctuations disappear after propagating a distance of one wavelength from the medium surfaces. For the random surfaces with smaller lateral correlation lengths, the speckle contrasts approach the saturation values and the speckle fields approach Gaussian distribution within the near-field, while for the random surfaces with larger lateral correlation lengths, such evolutions become comparatively slow.

关键词： speckle, near-field optics, first order statistics, Green's function.

Molecular modeling and spectroscopic studies on the binding of guaiacol to human immunoglobulin

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Science china Chemistry 2006年第6期49卷 550-559页

作者： HE Wenying1,2. YAO Xiaojun1, LIU Pengjun2. GAO Zhenxia2.& HU Zhide1 1. department of Chemistry, Lanzhou University, Lanzhou 730000,{4. 2. department of Chemistry, Hainan Normal University, Hainan 571158,{4. department of Chemistry Lanzhou University Lanzhou China department of Chemistry Hainan Normal University Hainan China

The fluorogenic property of guaiacol was exploited for the first time to analyze the interaction with target protein as a probe by molecular modeling, fluorescence, circular dichroism (CD) and Fourier transform infrared (FT-IR) spectroscopy. Molecular docking was performed to reveal the possible binding mode or mechanism and suggested that guaiacol can strongly bind to human immu- noglobulin (HIgG). It is considered that guaiacol binds to HIgG mainly by a hydrophobic interaction and there are two hydrogen bond interactions between the drug and the residues LEU 80 and ASP 65, which is in good agreement with the results from the experimental thermodynamic parameters (the enthalpy change △H0 and the entropy change △S0 were calculated to be 65.55 kJ·mol-1 and 132.95 J·mol-1·K-1 according to the Vant’ Hoff equation). Data obtained by the fluorescence spectroscopy indicated that binding of guaiacol with HIgG leads to dramatic enhancement in the fluorescence emission intensity along with significant occurrence of efficient Frster resonance energy transfer (FRET) from the residue of HIgG to the protein bound guaiacol. From the low value of fluorescence anisotropy (r = 0.06), it is argued that the probe molecule is located in the motionally unrestricted environment of the protein. The alterations of protein’s secondary structure in the presence of guaiacol in aqueous solution were quantitatively calculated by the evidences from FT-IR and CD spectroscopes.

关键词： guaiacol, human immunoglobulin, molecular modeling, fluorescence enhancement, Fourier transform infrared (FT-IR) spectroscopy, circular dichroism (CD).

Research on nonlinear constitutive relationship of permanent deformation in asphalt pavements

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Science china(physics,Mechanics & Astronomy) 2006年第6期49卷 671-682页

作者： PENG Miaojuan1 & XU Zhihong2.1. department of Civil Engineering,Shanghai University,Shanghai 2.0072.{4. 2. School of Transportation Engineering,Tongji University,Shanghai 2.0092.{4. department of Civil Engineering Shanghai University Shanghai China School of Transportation Engineering Tongji University Shanghai China

To predict correctly the rut depths in asphalt pavements,a new nonlinear viscoelastic-elastoplastic constitutive model of permanent deformation in asphalt pave-ments is presented. The model combines a generalized Maxwell model with an elasto-plastic one. Then from the creep theory,the linear and nonlinear constitutive equations of the generalized Maxwell model are obtained. From the nonlinear finite element method for the rutting of the asphalt pavement,the rut depths of 4.asphalt-aggregate mixtures are obtained. And the results are compared with the ones from the finite element method by SHRP and the experiments by SWK/UN. The results in this paper are better than the ones by SHRP,and agree with the ones of the experiment by SWK/UN. This shows that the nonlinear viscoelastic-elastoplastic constitutive model,which is presented in this paper for the rutting of the asphalt pavement,is effective. The properties,such as nonlinear elastic-ity,plasticity,viscoelasticity and nonlinear viscoelasticity,which affect the rutting of an asphalt pavement,can be shown in the model. And the characteristics of the permanent deformation of the asphalt pavement can be presented entirely in the model.

关键词： asphalt pavement,permanent deformation,nonlinear viscoelastic-elastoplastic constitutive relationship,generalized Maxwell model,creep compliance.

Solvothermal synthesis of nanocrystalline FeS_2

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Science china(physics,Mechanics & Astronomy) 2005年第2期48卷 188-200页

作者： CHEN Yanhua1, ZHENG Yufeng1, ZHANG Xiaogang2. SUN Yanfei1 & DONG Youzhong11. physics department of Xinjiang University, Urumqi 83004.,{2. 2. Institute of Applied Chemistry of Xinjiang University, Urumqi 83004.,{2. physics department of Xinjiang University Urumqi China Institute of Applied Chemistry of Xinjiang University Urumqi China

This paper reports on the synthesis of the nanocrystalline FeS2.via a solvent-thermal process. Using FeSO4.and NH2.SNH2.as precursors and polyvinyl- pyrrolidone (PVP) as a protective agent (dispersant), we have successfully synthesized nanocrystalline FeS2.both under acidic conditions (pH = 5) and under alkali conditions (pH = 10) at various temperatures and for different time in alcohol-water solution. X-ray diffraction (XRD), Transmission electron microscopy (TEM) and Ultraviolet Visible (UV-VIS) spectroscopy were used to characterize the morphology, structure, particle size and optical characterization of sample synthesized under acidic condition, and the XRD pattern was refined by Rietveld method. The experimental result shows that nanocrystalline FeS2.with uniform size, highly crystallized quality and excellent dispersivity has been synthesized at 2.0℃for 36 h.

关键词： FeS2 (Pyrite), solvothermal, PVP, the Rietveld method.

Empirical likelihood confidence regions of the parameters in a partially linear single-index model

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Science china Mathematics 2005年第10期48卷 1333-1348页

作者： XUE Liugen~1 & ZHU Lixing~2.1. College of Applied Sciences,Beijing University of Technology,Beijing 10002.,china 2. {4. of Mathematics,Hong Kong Baptist University,Hong Kong,china College of Applied Sciences Beijing University of Technology Beijing China department of Mathematics Hong Kong Baptist University Hong Kong China

In this paper, a partially linear single-index model is investigated, and three empirical log-likelihood ratio statistics for the unknown parameters in the model are suggested. It is proved that the proposed statistics are asymptotically standard chi-square under some suitable conditions, and hence can be used to construct the confidence regions of the parameters. Our methods can also deal with the confidence region construction for the index in the pure single-index model. A simulation study indicates that, in terms of coverage probabilities and average areas of the confidence regions, the proposed methods perform better than the least-squares method.

关键词： partially linear single-index model, empirical likelihood, confidence region, chi-square distribution, coverage probability.