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Characteristics of fluid substitution in porous rocks

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Petroleum Science 2009年第2期6卷 139-145页

作者： Li Shengjie School of Resource and Information Technology China University of Petroleum Beijing 102249 China State Key laboratory of Petroleum Resource and Prospecting China University of Petroleum Beijing 102249 China Key laboratory of CNPC Geophysical Exploration China University of Petroleum Beijing 102249 China

Analysis of the effect of changes in fluid properties of rocks on the compressional-wave velocity VP and shear-wave velocity Vs is very important for understanding the rock physical properties, especially in oilfield exploration and development. The fluid substitution process was analyzed by using ultrasonic measurement and theoretical calculations. The results showed that the effect of fluid substitution on the rock elastic modulus was mainly controlled by fluid properties, saturation, and confining pressure. For a rock with specific properties and porosity, the result of theoretical prediction for fluid substitution accorded with the experimental result under high confining pressure （higher than 60 MPa for our experimental data）, but failed to describe the trend of experimental result under low confining pressure and VP predicted by Gassmann＇s equation was higher than that measured by experiment. A higher porosity resulted in stronger sensitivity of the bulk modulus of saturated rocks to the change of fluid properties.

关键词： fluid substitution velocity bulk modulus porosity saturation

Analysis on the decadal scale variation of the dust storm in North china

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Science china Earth Sciences 2005年第12期48卷 2260-2266页

作者： KANG Dujuan1,2 & WANG Huijun1 1. NZC/LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences, beijing 100871, china 2. Environmental fluid Mechanics laboratory, Stanford university, Stanford CA 94305, USA 1. NZC/LASG Institute of Atmospheric Physics Chinese Academy of Sciences 100871 Beijing China 2. Environmental fluid Mechanics laboratory Stanford University 94305 Stanford CA USA

In this paper, the temporal variation characteristics of the dust storm in North china are investigated. Based on power spectrum analysis and wavelet analysis, 1956-1970 and 1985-1999 are chosen as the high-frequency and low-frequency dust storm decades respectively. Analysis results clearly show that the spring and wintertime anomalous atmospheric circulation between these two dec-ades are significantly different. Compared with the former decade, there are a strengthened polar vortex, enhanced westerlies near 50°N, and a weak East Asian major though in the winter of the latter decade. The north and center parts of the Siberian high and the Aleutian low become weak. The southerly and easterly wind anomalies appear over the north and east parts of china, which implies the weakening of East Asian winter monsoon. Meanwhile, northern china experiences warmer winters and wetter springs, which are in favor of the weakening of dust storm intensity in North china. There are significant out-of-phase relationships between dust frequency and wintertime westerly intensity, as well as between dust frequency and Arctic Oscillation. It is also found that the frequency of dust weather is strongly re-lated to winter-springtime East Asian monsoon intensity.

关键词： dust storm, climate anomaly, decadal scale variability, East Asian monsoon, AO.

Level Set interface treatment and its application in Euler method

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Science china(Physics,Mechanics & Astronomy) 2010年第2期53卷 227-236页

作者： WU KaiTeng1,2,HAO Li3,WANG Cheng4 & ZHANG Li1,2 1 Numerical Simulation Sichuan Higher School Key laboratory,Neijiang Normal university,Neijiang 641112,china 2 College of Mathematics and Information Science,Neijiang Normal university,Neijiang 641112,china 3 College of Science,beijing university of Civil Engineering and Architecture,beijing 100044,china 4 State Key laboratory of Explosion Science and Technology,beijing Institute of Technology,beijing 100081,china 1. Numerical Simulation Sichuan Higher School Key laboratory Neijiang Normal University Neijiang 641112 China2. College of Mathematics and Information Science Neijiang Normal University Neijiang 641112 China3. College of Science Beijing University of Civil Engineering and Architecture Beijing 100044 China4. State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology Beijing 100081 China

Level Set interface treatment method is introduced into Euler method,which is employed for interface treatment method for multi-materials. Combined with the ghost fluid method,the moving interface is tracked. Fifth-order WENO spatial discretization and third-order TVD Runge-Kutta time discretization methods are used. Shock-wave action on bubble,implosion and velocity field Shock effect bubbles; implosion and velocity field are simulated by means of LS-MMIC3D programmed by C++. Nu-merical results show that the Level Set interface treatment method is effective and feasible for multi-material interface treatment in comparison with the WENO method.

关键词： Euler method Level Set method shock-wave action on bubble implosion numerical simulation

Numerical and experimental investigation of the fracture behavior of shock loaded alumina

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Science china(Physics,Mechanics & Astronomy) 2010年第2期53卷 244-252页

作者： REN HuiLan1,SHU XueFeng2 & LI Ping3 1 State Key laboratory of Explosion Science and Technology,beijing Institute of Technology,beijing 100081,china 2 Institute of Applied Mechanics and Biomedical Engineering,Taiyuan university of Technology,Taiyuan 030024,china 3 Labroratory for Shock Wave and Detonation Physics Research,Institute of fluid Physics,CAEP,Mianyang 610059,china 1. State Key laboratory of Explosion Science and Technology Beijing Institute of Technology Beijing 100081 China2. Institute of Applied Mechanics and Biomedical Engineering Taiyuan University of Technology Taiyuan 030024 China3. Labroratory for Shock Wave and Detonation Physics Research Institute of Fluid Physics CAEP Mianyang 610059 China

Plate impact expeiments are conducted to investigate the dynamic behavior of alumina by using one stage light gas gun. A ve-locity interferometer system for reflectors (VISAR) is used to obtain Hugoniot elastic limit and the free surface velocity profile,which consists of an elastic wave followed immediately by a dispersive inelastic wave. The stress histories under different impact velocities are measured by in-material manganin gauges. Based on the experimental data a Hugoniot curve is fitted,which shows the compressive characteristics that alumina changes typically from elastic to "plastic" ,and under higher pressure it will be transferred to similar-fluid state. The turning point of the Hugoniot curve from a high pressure region to a low pressure region is about 11.4 GPa. The fracture process of alumina is simulated by way of finite element code. After the analysis of the fracture mechanism,the numerical results show an important role played by the nucleation and the growth of the cracks in the macro-scopic fracture of the alumina target. The numerical predictions of stress histories are compared with the experimental results,which indicates consistency between them.

关键词： plate impact experiment hugoniot curve fracture characteristics numerical simulation

^(13)C NMR spectra of tectonic coals and the effects of stress on structural components

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Science china Earth Sciences 2005年第9期48卷 1418-1437页

作者： JU Yiwen1,2, JIANG Bo1, HOU Quanlin2, WANG Guiliang1 & NI Shanqin2 1. College of Mineral Resource and Geosciences, china university of Mining and Technology, Xuzhou 221008, china 2. laboratory of computational Geodynamics, College of Geosciences, Graduate School of Chinese Academy of Sciences, beijing 100049, china 1. College of Mineral Resource and Geosciences China University of Mining and Technology 221008 Xuzhou China 2. laboratory of computational Geodynamics College of Geosciences Graduate School of Chinese Academy of Sciences 100049 Beijing China

High-resolution 13C Nuclear Magnetic Resonance (NMR) spectra of different kinds of tectonic coals were obtained using the NMR (CP/MAS+TOSS) method. On the basis of this, after simulation synthesis and division of spectra, the relative contents of carbon functional groups were calculated. Combined with results of Ro, max, XRD testing and element analysis, stress effects on the composition of macromolecular structures in tectonic coals were studied further. The results showed that Ro, max was not only the important index for describing coal rank, but was also effective for estimating the stress effect of tectonic coals. Under tectonic stress ac- tion, Ro, max was the most direct indicator of the coal structure and chemical components. Changes in the stacking Lc of the coal basic structure unit (BSU) and La/Lc parameters could distinguish the temperature and stress effects on metamorphic-deformed environments, and re- flected the degree of structural deformation. Therefore, on the whole, Lc and La/Lc can be used to index of the degree of structural deformation of tectonic coals. In different metamorphic and de- formed environments, different kinds of tectonic coals are formed under structural stress. The changes in characteristics of the macromolecular structure and chemical composition are such that as the increase in structural deformation becomes stronger, from the brittle deformation coal to ductile deformation coal, the ratio of width at the half height of the aromatic carbon and ali- phatic carbon peaks (Hfa/Hfal ) was increased. As carbon aromaticity was raised further, carbon aliphaticity reduced obviously and different compositions of macromolecular structure appeared as a jump and wave pattern except for in wrinkle structure coal, which might result chiefly from stress effects on the macromolecular structure of different kinds of tectonic coals. The macro- moecular changes of wrinkle structure coal are reflected mainly on physical structure. In the metamorphi

关键词： tectonic coal, NMR, macromolecular structure, chemical component, stress effect.

THE STUDY OF ENTROPY CORRECTION FUNCTION IN TVD SCHEMES

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THE STUDY OF ENTROPY CORRECTION FUNCTION IN TVD SCHEMES

Effects of hydrogen on a tungsten grain boundary:A first-principles computational tensile test

第四届亚洲计算流体力学会议

作者： LU Ye WU Song Pingnational laboratory of computational fluid dynamics beijing university of Aeronautics and Astronautics beijing 100083 china

＜正＞ A modified form based on Yee’s velocity-dependent entropy correction function is proposed and some factors are considered in this form such as the subsonic region behind shock waves, the temperature-increasing section and the aspect ratio of grids. It can keep the flow parameters well when simulating the chemically reacting flows over complex three-dimension body and acquire the satisfactory flow characteristics.

关键词： hypersonic flows TVD scheme entropy correction function

来源： cnki会议评论

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Progress in Natural Science:Materials International 2011年第3期21卷 240-245页

作者： Hong-bo ZHOU,Shuo JIN,Ying ZHANG,Guang-hong LU Department of Physics,Key laboratory of Micro-nano Measurement-Manipulation and Physics(Ministry of Education),beijing university of Aeronautics and Astronautics,beijing 100191,china Department of Physics Key Laboratory of Micro-nano Measurement-Manipulation and Physics (Ministry of Education) Beijing University of Aeronautics and Astronautics Beijing 100191 China

A first-principles computational tensile test has been preformed to investigate the effects of hydrogen on a tungsten grain *** has been found that the maximum ideal tensile strength of the tungsten grain boundary with hydrogen atom segregation was 32.85 GPa,which was about 9%lower than that of the clean tungsten grain boundary(36.23 GPa).This indicated that the theoretical strength of the tungsten grain boundary became weaker in the presence of the hydrogen *** configuration analysis showed that the grain boundary fracture was caused by the interfacial bond *** Griffith fracture energy was calculated to be 161 meV/A~2(2.58 J/m~2) and 155 meV/A~2(2.48 J/m~2) for the tungsten grain boundary without and with the hydrogen atom segregation,*** solution energy of the hydrogen atom in a fracture free surface was -0.31 eV,which was 0.08 eV lower than that of the hydrogen atom in a tungsten grain *** indicated that hydrogen was a grain boundary embrittler according to the Rice-Wang thermodynamic *** Bader charge analysis suggested that the physical origin for hydrogen-induced embrittlement was the charge transfer induced by hydrogen in the tungsten grain boundary.

关键词： tungsten hydrogen grain boundary tensile strength first-principles

Quantum chemical calculations of nitrogen cages N_(12)

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Chinese Science Bulletin 1997年第6期42卷 462-465页

作者： QU Hong, LI Qianshu and ZHU HesunSchool of Chemical Engineering and Materials Science of beijing Institute of Technology, beijing 100081, china Stale Key laboratory of Theoretical and computational Chemistry, Jilin university, Changchun 130023, china School of Chemical Engineering and Materials Science of beijing Institute of Technology Beijing China State Key laboratory of Theoretical and computational Chemistry Jilin University Changchun China

WHILE carbon fullerenes are studied theoretically, we tend to predict if there may be some pure nitrogen molecules which possibly consist of the same geometric structures as carbon fullerenes. Experimentally Vogler et al. have obtained the intermediate absorbed at 380 nm which was assigned to N6 molecules in 1980. Some reports of ab initio calculations have appeared concerning theoretical aspects of nitrogen cage-like structures. Bliznyuk et *** the geometrical structure of N20 molecules with Ih symmetry at HF level, showing that N20 has a metastable dodecahedral geometry, with 209.34 kJ of nitrogen atoms more than that of 10N2. The N20 molecule might be a very effective high energy density

关键词： nitrogen cage ab initio calculation HEDM.

Origin of a native sulfur chimney in the Kueishantao hydrothermal field, offshore northeast Taiwan

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Science china Earth Sciences 2007年第11期50卷 1746-1753页

作者： ZENG ZhiGang1, LIU ChangHua1,2, CHEN ChenTung A3, YIN XueBo1, CHEN DaiGeng1,2, WANG XiaoYuan1,2, WANG XiaoMei1,2 & ZHANG GuoLiang1,2 1 Seafloor Hydrothermal Activity laboratory of the Key laboratory of Marine Geology and Environment, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, china 2 Graduate university of Chinese Academy of Sciences, beijing 100049, china 3 Institute of Marine Geology and Chemistry, national Sun Yat-Sen university, Kaohsiung 804, Taiwan, china 1. Seafloor Hydrothermal Activity laboratory of the Key laboratory of Marine Geology and Environment Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China 2. Graduate university of Chinese Academy of Sciences Beijing 100049 China 3. Institute of Marine Geology and Chemistry National Sun Yat-Sen University Kaohsiung 804 Taiwan China

Analyses of rare earth and trace element concentrations of native sulfur samples from the Kueishantao hydrothermal field were performed at the Seafloor Hydrothermal Activity laboratory of the Key Labo-ratory of Marine Geology and Environment, Institute of Oceanology, Chinese Academy of Sciences. Using an Elan DRC II ICP-MS, and combining the sulfur isotopic compositions of native sulfur samples, we studied the sources and formation of a native sulfur chimney. The results show, when comparing them with native sulfur from crater lakes and other volcanic areas, that the native sulfur content of this chimney is very high (99.96%), the rare earth element (REE) and trace element constituents of the chimney are very low (ΣREEfluid-andesite at the Kueishantao hydrothermal field was of short duration. The sulfur isotopic compo-sitions of the native sulfur samples reveal that the sulfur of the chimney, from H2S and SO2, originated by magmatic degassing and that the REEs and trace elements are mostly from the Kueishantao ande-site and partly from seawater. Combining these results with an analysis of the thermodynamics, it is clear that from the relatively low temperature (<116 ℃ ), the oxygenated and acidic environment is favorable for formation of this native sulfur chimney in the Kueishantao hydrothermal field.

关键词： origin,native sulfur chimney,Kueishantao hydrothermal field,northeast Taiwan