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Experimental studies on perturbed acoustic resonant spectroscopy by a small rock sample in a cylindrical cavity

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Science china(Physics,Mechanics & Astronomy) 2006年第6期49卷 683-701页

作者： CHEN Dehua1,2.WANG Xiuming2.3,CONG Jiansheng1,XU Delong1,SONG Yanjie1 & MA Shuilong4 1. Department of Geophysics,Daqing Petroleum institute,Daqing 163318,china {2.,chinese academy of sciences,beijing 100080,china 3. Division of Petroleum,Australian Commonwealth Scientific and Industrial Research Organization,Bent-ley WA 6102.Australia 4. Daqing Testing and Technology Services Corporation,Daqing 163153,china Department of Geophysics Daqing Petroleum Institute Daqing 163318 China institute of acoustics Chinese Academy of Sciences Beijing 100080 China Division of Petroleum Australian Commonwealth Scientific Industrial Research Organization Bentley WA 6102 Australia Daqing Testing Technology Services Corporation Daqing 163153 China

A measurement system for acoustic resonant spectroscopy (ARS) is estab-lished,and the effects of resonant cavity geometry,inner perturbation samples and envi-ronmental temperature on the ARS are investigated. The ARSs of the small samples with various sizes and acoustic properties are measured. The results show that at the normal pressure,the resonant frequency decreases gradually with the increase of liquid tem-perature in the cylindrical cavity,while the resonant amplitude increases. At certain pres-sure and temperature,both the resonant frequency and the amplitude decrease greatly when there exist air bubbles inside the cavity fluid. The ARS is apparently affected by the sample porosity and the sample location in the resonant cavity. At the middle of the cavity,the resonant frequencies reach their maximum values for all of the measurement samples. The resonant frequencies of the porous rock samples are smaller than those of the com-pacted samples if other acoustic parameters are the same. As the sample is moved from the top to the middle of the cavity along its axis,the resonant amplitude increases gradu-ally for the compacted rocks while decreases for the unconsolidated rocks. Furthermore,the resonant amplitude increases firstly and then decreases if the porosity of the rock sample is relatively small. In addition,through the comparisons between the experimental and theoretical results,it is found that the effects of the acoustic parameters and sizes of the samples and the size of the cylindrical cavity on the laboratory results agree well with the theoretical ones qualitatively. These results may provide basic reference for the ex-periment study of rock acoustic properties in a low frequency using ARS.

关键词： acoustic resonant spectroscopy,acoustic velocity and attenuation,experiment measurement,rock acoustic property.

SYNTHESIS AND CHARACTERIZATION OF NEW STABILIZERS WITH OPTIMAL MOLECULAR WEIGHT

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chinese Journal of Polymer Science 2001年第4期19卷 341-350页

作者： Jiang-qing Pan institute of Chemistry chinese academy of sciences,{2. china chinese Acad Sci Inst Chem Beijing 100080 Peoples R China

Over 2.x 10(8) tons of polymers are produced every year, and a large portion of polymers faces the degradation problem. There are many effective methods to protect polymers against degradation and the addition of stabilizers to polymer remains the most convenient and effective way of enhancing polymer life and performance. In this article, a series of effective stabilizers with optimal molecular weight (MW), including common, monomeric and polymeric stabilizers (antioxidant and light stabilizer) were synthesized using isocyanation, controlled isocyanation, hydrosilylation, epoxide addition, macroreaction of stabilizing functional compounds and polymerization of monomeric stabilizers. The structure and performance of these new stabilizers were characterized by using IR, NMR, MS, UV-spectra, XPS and elemental analysis. The current development of stabilizer synthesis was also reviewed.

关键词： preparation of stabilizer antioxidant hindered amine light stabilizer isocyanation hydrosilylation

A mixed method for measuring low-frequency acoustic properties of macromolecular materials

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Science china(Physics,Mechanics & Astronomy) 2006年第6期49卷 729-739页

作者： LIU Hongwei1,YAO Lei1,3,ZHAO Hong1,3,ZHANG Jichuan2.3 & XUE Zhaohong2.1. National Key Laboratory of acoustics,institute of acoustics,chinese academy of sciences,beijing 100080,china 2. institute of Chemistry,chinese academy of sciences,beijing 100080,china 3. Graduate University of chinese academy of sciences,beijing 100049,china National Key Laboratory of acoustics Institute of Acoustics Chinese Academy of Sciences Beijing 100080 China institute of Chemistry Chinese Academy of Sciences Beijing 100080 China Graduate University of chinese academy of sciences Beijing 100049 China

A mixed method for measuring low-frequency acoustic properties of macro-molecular materials is presented. The dynamic mechanical parameters of materials are first measured by using Dynamic Mechanical Thermal Apparatus(DMTA) at low frequen-cies,usually less than 100 Hz; then based on the Principles of Time-Temperature Super-position (TTS),these parameters are extended to the frequency range that acousticians are concerned about,usually from hundreds to thousands of hertz; finally the extended dynamic mechanical parameters are transformed into acoustic parameters with the help of acoustic measurement and inverse analysis. To test the feasibility and accuracy,we measure a kind of rubber sample in DMTA and acquire the basic acoustic parameters of the sample by using this method. While applying the basic parameters to calculating characteristics of the sample in acoustic pipe,a reasonable agreement of sound absorp-tion coefficients is obtained between the calculations and measurements in the acoustic pipe.

关键词： low-frequency acoustic properties,dynamic mechanical properties,Principles of Time-Temperature Superposition,acoustic pipe,sound absorption coefficient.

Algebraically explicit analytical solu-tions for the unsteady non-Newtonian swirling flow in an annular pipe

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Science china(Physics,Mechanics & Astronomy) 2006年第4期49卷 396-400页

作者： CAI Ruixian1 & GOU Chenhua1,2.1. institute of Engineering Thermophysics, chinese academy of sciences,{2., china 2. Graduate School, chinese academy of sciences,{2., china 1. institute of Engineering Thermophysics Chinese Academy of Sciences Beijing 100080 China 2. Graduate School Chinese Academy of Sciences Beijing 100080 China

This paper presents two algebraically explicit analytical solutions for the incompressible unsteady rotational flow of Oldroyd-B type in an annular pipe. The first solution is derived with the common method of separation of variables. The second one is deduced with the method of separation of variables with addition developed in recent years. The first analytical solution is of clear physical meaning and both of them are fairly simple and valuable for the newly developing computational fluid dynamics. They can be used as the benchmark solutions to verify the applicability of the existing numerical computational methods and to inspire new differencing schemes, grid generation ways, etc. Moreover, a steady solution for the generalized second grade rheologic fluid flow is also presented. The correctness of these solutions can be easily proven by substituting them into the original governing equation.

关键词： analytical solution, Oldroyd-B type fluid, swirling flow, non-Newtonian.

Some key technics of drop tower experiment device of National Microgravity Laboratory (china) (NMLC)

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Science china(Technological sciences) 2005年第3期48卷 305-316页

作者： ZHANG Xiaoqian 1 , YUAN Longgen 1 , WU Wendong 1 , TIAN Lanqiao 2.& YAO Kangzhuang 2.1. institute of Engineering Thermophysics, chinese academy of sciences,{2., china 2. institute of Mechanics, chinese academy of sciences,{2., china 1. institute of Engineering Thermophysics Chinese Academy of Sciences 100080 Beijing China 2. institute of Mechanics Chinese Academy of Sciences 100080 Beijing China

Drop tower is an important ground based facility for microgravity science experiment. The technical performances of the drop tower NMLC are advanced compared with similar facilities in the US, Germany and Japan. The main components such as drop capsule, deceleration devices, release mechanism present its advantages and creativities.

关键词： drop tower facility,drop capsule,deceleration devices,release mechanism.

Transformations and non-degenerate maps

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Science china Mathematics 2005年第z1期48卷 195-205页

作者： LI Baokui & WANG Yuefei institute of Mathematics, academy of Mathematics and System {2., chinese academy of sciences, beijing 100080, china Graduate School, chinese academy of sciences, beijing 100080, china 1. institute of Mathematics Academy of Mathematics and System Sciences Chinese Academy of Sciences 100080 Beijing China 2. Graduate School Chinese Academy of Sciences 100080 Beijing China

We shall prove the equivalences of a non-degenerate circle-preserving map and a M(o)bius transformation in ^Rn, of a non-degenerate geodesic-preserving map and an isometry in Hn of a non-degenerate line-preserving map and an affine transformation in Rn. That a map is non-degenerate means that the image of the whole space under the map is not a circle, or geodesic or line respectively. These results hold without either injective or surjective, or even continuous assumptions, which are new and of a fundamental nature in geometry.

关键词： M(o)bius transformation, circle-preserving map, non-degenerate map.

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B_c Meson Studies

高能物理与核物理 2002年第Z1期26卷 1-10页

作者： CHANG Chao-Hsi (institute of Theoretical Physics, chinese academy of sciences,{2., china) Inst. of Theor. Phys. Chinese Acad. of Sci. Beijing 100080 China

Our studies on the meson Bc arc briefly *** decays of the meson Bc to a P-wave charmonium Xc or hc are reported comparatively precisely because they are fresh

关键词：高能物理核物理增刊张肇西 B_c Meson Studies Rev

A NEW STABILIZED FINITE ELEMENT METHOD FOR SOLVING THE ADVECTION-DIFFUSION EQUATIONS

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Journal of Computational Mathematics 2002年第1期20卷 57-64页

作者： Huo-yuan Duan (institute of Mathematics, academy of Mathematics and System {2., chinese academy of sciences, beijing 100080, china) institute of Mathematics Academy of Mathematics and System Sciences Chinese Academy of Sciences 北京 100080

Focuses on a study on the development of a stabilized finite element method for solving the advection-diffusion equations with a zero Dirichlet boundary condition. Problem formulation; Error analysis.

关键词： advection-diffusion equation stabilized finite element method

N DIMENSIONAL FINITE WAVELET FILTERS

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Journal of Computational Mathematics 2003年第5期21卷 595-602页

作者： Si-long Peng (NADEC, institute of Automation, chinese academy of sciences,{2., china) NADEC Institute of Automation Chinese Academy of Sciences 北京 100080

In this paper, a large class of n dimensional orthogonal and biorthognal wavelet filters (lowpass and highpass) are presented in explicit expression. We also characterize orthogonal filters with linear phase in this c... 详细信息

关键词： n Dimension Linear phase Wavelet filters.