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Gasdynamic characteristics of toroidal shock and detonation wave converging

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Science china(Physics,Mechanics & Astronomy) 2005年第6期48卷 739-749页

作者： TENG Honghui1,2.& JIANG Zonglin2.1. Key Laboratory of High Temperature Gas Dynamics, Institute of Mechanics, chinese academy of Sci- ences, {2. 100080, china 2. graduate University of chinese academy of sciences, {2. 100039, china 1. Key Laboratory of High Temperature Gas Dynamics Institute of Mechanics Chinese Academy of Sciences 100080 Beijing China 2. graduate University of chinese {2. of sciences 100039 Beijing China

The modified CCW relation is applied to analyzing the shock, detonation wave converging and the role of chemical reactions in the process. Results indicate that the shock wave is strengthened faster than the detonation wave in the converging at the same initial Mach number. Euler equations implemented with a detailed chemical reaction model are solved to simulate toroidal shock and detonation wave converging. Gasdynamic characteristics of the converging are investigated, including wave interaction patterns, observable discrepancies and physical phenomena behind them. By comparing wave diffractions, converging processes and pressure evolutions in the focusing area, the different effects of chemical reactions on diffracting and converging processes are discussed and the analytic conclusion is demonstrated through the observation of numerical simulations.

关键词： converging, CCW relation, shock wave, detonation wave.

Ashkin-Teller Formalism for Elastic Response of DNA Molecule to External Force and Torque

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Communications in Theoretical Physics 2008年第2期49卷 525-528页

作者： CHANG Zhe~1 WANG Ping~(1,2. ZHENG Ying-Hong~(1,2. 1 Institute of High Energy Physics,the chinese academy of {2.,P.O.Box 918(4),beijing 100049,china 2.graduate School,the chinese academy of {2.,beijing 100049,china Institute of High Energy Physics the Chinese Academy of Sciences P.O. Box 918(4) Beijing 100049 China graduate School the Chinese Academy of Sciences Beijing 100049 China

We propose an Ashkin Teller-like model for elastic response of DNA molecule to external force and *** base-stacking interaction is described in a simple and uniform *** obtain the phase diagram of dsDNA,andin particular,the transition from B form to the S state induced by stretching and *** elastic response of thessDNA is presented also in a unified *** close relation of dsDNA molecule structure with elastic response isshown *** calculated folding angle of the dsDNA molecule is 59.2..

关键词： dsDNA elastic property

Transient species and its properties of melatonin

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Science china Chemistry 2006年第4期49卷 308-314页

作者： ZHU Hongping1,2. ZHANG Zhaoxia1,2. ZHAO Hongwei1, WANG Wenfeng1 & YAO Side1 1. Shanghai Institute of Applied Physics, chinese academy of {2., Shanghai 2.1800, china 2. graduate University of the chinese academy of {2., beijing 100049, china 1. Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800 China 2. graduate University of the chinese {2. of sciences Beijing 100049 China

The photo-physical and photo-chemical properties of melatonin (ML) werestudied by 2.6 nm laser flash photolysis (LFP). ML undergoes photo-ionization to produce radicalcation of ML (ML^(·+))and hydrated electrons (e_(aq)^-), while excited triplet state ~3ML~* is alsoformed during photolysis. The oxidation via one electron transfer from ML to SO_4^(·+) and thetriplet state of riboflavin (~3RF~*) has been also investigated and the rate constants for theprocess have been determined to be 8.0x10^9 and 1.4x10^9 L·mol^(-1)·s^(-1) respectively. Theradical cation of 2.2.'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS^(·+)) scavengingcapacities of melatonin and other antioxidants are compared in this paper.

关键词： melatonin, laser flash photolysis, photoionization, triplet state.

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 {2., beijing 100080, china 2. graduate School of the chinese academy of {2., beijing 100039, china 1. Institute of Engineering Thermophysics Chinese Academy of Sciences 100080 Beijing China 2. graduate School of the chinese {2. 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.

Analysis and application of automatic deformation monitoring data for buildings and structures of mining area

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中国有色金属学会会刊：英文版 2011年第S3期21卷 516-522页

作者： XIAO Jie1, 2. 3, ZHANG Jin4 1. Institute of Geodesy and Geophysics, chinese academy of {2., Wuhan 430077, china 2. Key Laboratory of Dynamic Geodesy, Institute of Geodesy and Geophysics, chinese academy of {2., Wuhan 430077, china 3. graduate School of chinese academy of {2.,{12., china 4. Department of Surveying and Mapping, Taiyuan University of Technology, Taiyuan 03002., china Taiyuan Univ Technol Dept Surveying & Mapping Taiyuan 030024 Peoples R China chinese Acad Sci Inst Geodesy & Geophys Key Lab Dynam Geodesy Wuhan 430077 Peoples R China chinese Acad Sci Grad Sch Beijing 100049 Peoples R China

The buildings and structures of mines were monitored automatically using modern surveying technology. Through the analysis of the monitoring data, the deformation characteristics were found out from three aspects containing points, lines and regions, which play an important role in understanding the stable state of buildings and structures. The stability and deformation of monitoring points were analysed, and time-series data of monitoring points were denoised with wavelet analysis and Kalman filtering, and exponent function and periodic function were used to get the ideal deformation trend model of monitoring points. Through calculating the monitoring data obtained, analyzing the deformation trend, and cognizing the deformation regularity, it can better service mine safety production and decision-making.

关键词： wavelet analysis Kalman filtering deformation monitoring data analysis mine

Nonlinear interactions between gravity waves and background winds

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Progress in Natural Science:Materials International 2007年第6期17卷 639-644页

作者： Liu Xiao1,2.and Xu Jiyao1(1. State Key Laboratory for Space Weather, Center for Space Science and Applied Research, chinese academy of {2., beijing 100080, china 2. graduate University of chinese academy of {2., beijing 100039, china) [a]State Key Laboratory for Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing China [b]graduate University of chinese {2. of sciences Beijing China

Using the nonlinear propagating gravity waves (GW) model in the two-dimensional compressible atmosphere and the linear GW theory, the process of GW propagation in different background winds, e.g. the direction of the background wind is opposite to (dead wind) or the same as (tail wind) the direction of the horizontal phase velocity of GW, is studied. The results show that the dead wind prolongs the vertical wavelength and accelerates GW propagation. Therefore, GW propagates up to a higher height becomes instable in a short time and eventually induces an inverse jet flow. Then, the vertical wavelength is becoming short due to the nonlinear interactions between GW and the inverse jet flow. The vertical wavelength and group velocity decrease after GW propagates into the tail wind. The initial instable time is delayed. Although most of GW is trapped in the instable region, some of GW propagates above the instable region. Compared with GW propagation in the tail wind, the nonlinear interactions between GW and the dead wind are also strong. In contrast, the linear GW theory predicts that GW can propagate freely in the dead wind. The vertical wavelength simulated by the nonlinear numerical model is different from that predicted by the linear theory greatly after GW propagates into the dead wind.

关键词： gravity waves background winds vertical group velocity vertical wavelength nonlinear interactions.

A Test on Different Types of the Time Curve of Hardness Ratio of Gamma-Ray Bursts based on the Curvature Effect

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chinese Journal of Astronomy and Astrophysics 2008年第4期8卷 451-464页

作者： Lan-Wei Jia National Astronomical Observatories/Yunnan Observatory,chinese academy of {2.,Kunming 650011,china graduate School of chinese academy of {2.,beijing 100049,china National Astronomical Observatories/ Yunnan Observatory Chinese Academy of Sciences Kunming 650011 China and graduate School of chinese {2. of sciences Beijing 100049 China

We analyzed a sample of 66 gamma-ray bursts （GRBs） and statistically confirmed the prediction on the time curve of the hardness ratio of GRBs made by Qin et al. based on the curvature effect. In their analysis, GRB pulses are divided into three types according to the shape of their raw hardness ratio （RHR） time curves, defined as to include the background counts to the signal counts, so as to make use of counts within small time intervals. Of the three types, very hard sources exhibit a perfect pulse-like profile （type 1）, hard bursts possess a pulse-like profile with a dip in the decay phase （type 2., and soft bursts show no pulse-like profile but have only a dipped profile （type 3）. In terms of the conventional hardness ratio, type 3 sources are indeed generally softer than those of type 1 and type 2. in agreement with the prediction. We found that the minimum value of RHR is sensitive in distinguishing the different types. We propose that GRB pulses can be classified according to the minimum value of RHR and that the different type sources may be connected with different strengths of the shock or/and the magnetic field.

关键词： gamma-rays burst -- gamma-rays observations - methods statistical

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 {2.,beijing 100080,china 2. Institute of Chemistry,chinese academy of {2.,beijing 100080,china 3. graduate University of chinese academy of {2.,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 {2. 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.

Effect of concentration on surfactant micelle shapes——A molecular dynamics study

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Science china Chemistry 2005年第5期48卷 470-475页

作者： GAO Jian1,2. GE Wei1 & LI Jinghai1 1. Multiphase Reaction Laboratory, Institute of Process Engineering, chinese academy of {2., beijing 100080, china 2. graduate School of The chinese academy of {2., beijing 100085, china 1. Multiphase Reaction Laboratory Institute of Process Engineering Chinese Academy of Sciences 100080 Beijing China 2. graduate School of The chinese {2. of sciences 100085 Beijing China

Many aspects of the behavior of surfactants have not been well understood due to the coupling of many different mechanisms. Computer simulation is, therefore, attractive in the sense that it can explore the effect of different mechanisms separately. In this paper, the shapes, structures and sizes of sodium dodecylbenzenesulfonate (SDBS) micelles under different con-centrations in an oil/water mixture were studied via molecular dynamics (MD) simulations using a simplified atomistic model which basically maintains the hydrophile and lipophile properties of the surfactant molecules. Above the critical micellar concentration (cmc), surfactant molecules ag-gregate spontaneously to form a wide variety of assemblies, from spherical to rodlike, wormlike and bilayer micelles. Changes in their ratios of the principle moments of inertia (g1/g3, g2.g3) in-dicated the transition of micelle shapes at different concentrations. The aggregation number of micelle is found to have a power-law dependence on surfactant concentration.

关键词： surfactant, MD simulation, sodium dodecylbenzenesulfonate, micelle shape.