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3. Modeling Quantitative Evaluation for the Underground Space Resources in beijing City

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地学前缘 2009年第S1期16卷 283-284页

作者： Yi Tian,Jianping Chen,Limei Wang School of Land Resources and Technology,China University of Geosciences(beijing),beijing 100083.China.

Recently,underground space evaluation has become fundamental for a city’s long term sustainable development *** paper,based on the 3.-GIS tools,adopts"multi-factors comprehensive evaluation"models to establish a prac... 详细信息

关键词： city underground space resources quantitative evaluation 3. modeling

Prediction of Enthalpies of Fusion for Divalent Rare Earth Halides Based on Modeling by Artificial Neural Networks and Pattern Recognition

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International Journal of Minerals,Metallurgy and Materials 1999年第1期13卷 24-26页

作者： Yimin Sun Zhiyu Qiao Minghong He(Applied Science School, University of Science & Technology beijing, beijing 100083. China)(National Natural Science Foundation of China, beijing 100083. China) Applied Science School University of Science and Technology Beijing Beijing 100083 China National Natural Science Foundation of China Beijing 100083 China

The artificial neural network (ANN) and the pattern recognition were applied to study the correlation of enthalpies of fusion for divalent rare earth halides with their microstructural parameters,such as ionic radius and electronegativity. The model,represented by a back-propagation netal network, was trained with a 12 set of published data for divalent rare earth halides and then was used to predict the unknown ones. Also the criterion equations were ptesented to determine the enthalpies of fuSion for divalent rare earth halides using pattern recognition in mis work. The results from the model in ANN and criterion equations are in very good agreement with reference data.

关键词： BP neural network pattern recognition enthalpy of fusion divalent rare earth halides microstructural parameters

Seismic wave propagating in Kelvin-Voigt homogeneous visco-elastic media

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Science China Earth Sciences 2006年第2期49卷 147-153页

作者： YUAN Chunfang1, PENG Suping1, ZHANG Zhongjie2 & LIU Zhenkuan3.1. China University of Mining & Technology, beijing 100083. China 2. Institute of Geophysics, Chinese Academy of Sciences, beijing 100101, China 3. Exploration and Development Research Institute of Daqing Oilfield, Daqing 163.12, China China University of Mining & Technology Beijing China Institute of Geophysics Chinese Academy of Sciences Beijing China Exploration and Development Research Institute of Daqing Oilfield Daqing China

This paper studies, under a small disturbance, the responses of seismic transient wave in the visco-elastic media and the analytic solution of the corresponding third-order partial differential equation. A plane wave solution of Kelvin-Voigt homogeneous visco-elastic third-order partial differ-ential equation with a pulse source is obtained. By the principle of pulse stacking of particle vibration, the result is extended to the solution of Kelvin-Voigt homogeneous visco-elastic third-order partial differential equation with any source. The velocities of seismic wave propagating and the attenuation of seismic wave in Kelvin-Voigt homogeneous visco-elastic media are discussed. The velocities of seismic wave propagating and the coefficient of attenuation of seismic wave in Kelvin-Voigt homogeneous visco-elastic media are derived, expressed as functions of density of the media, elastic modulus and visco-elastic coefficient. These results can be applied in inversing lithology parameters in geophysical prospecting.

关键词： Kelvin-Voigt visco-elastic velocity attenuation seismic wave.

Effects of rare earth element lanthanum on the microstructure of copper matrix diamond tool materials

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Rare Metals 2002年第2期21卷 90-94页

作者： JIAChengchang SONGYueqing YUMing WANGTing ResearchInstituteofPowderMetallurgyUniversityofScienceandTechnologybeijing Beijing100083China GeneralResearchInstituteofNon-ferrousMetal Beijing100088China

Effects of rare earth element La on the microstructure of Cumatrix diamond tools were researched under the conditions of variousmaterials components and the process parameters in order to improvematerials properties. SEM, XPS and X-ray were used to investigate thefracture section, microstructure and the element valence inmaterials. The Results shown that the combination of rare earthelement La and transition element Ti is advantageous to the bondingstate Between diamond particles and matrix, so it can improve thematerials properties. Suitable sintering temperature is 790 deg. C.

关键词： rare earth element La interface reaction Copper matrix diamond tool titanium

Algorithm for Computation of Unstructured Real Stability Radius and Its Applications

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International Journal of Minerals,Metallurgy and Materials 1998年第4期12卷 245-250页

作者： Xiaodan Zhang Lequan Min(Applied Science School, University of Science and Technology beijing, beijing 100083. China) Applied Science School University of Science and Technology Beijing Beijing 100083 China

An algorithm for the computation of the unstructured real stability radius of high dimensional linearsystem is presented. Using the accurate formula of the real stability radius of 2-dimensional system linear systemchecks the algorithm. The result shows that the algorithm is reliable and efficient. As applications, the unstructuredreal stability radii of 2-dimensional Chua's circuit and 3.dimensional piecewise-linear system are calculated, thedynamical orbits of the corresponding perturbed systems are simulated.

关键词： lincar systems stability robustness parameter perturbation computational methods

MEAM Potential with Angular Dependence for TiAl

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Rare Metals 2001年第1期20卷 13-17页

作者： Xiaodong Ni, Xitao Wang, Guoliang Chen (Physics Department, University of Science and Technology beijing, beijing 100083. China State Key Laboratory for Advanced Metals and Materials, University of Science and Technology beijing, beijing 100083. China) 北京科技大学新金属材料国家重点实验室北京 100083 北京科技大学北京 100083

The modified embedded atom method (MEAM) is an empirical extension of the embedded atom method (EAM) that includes angular forces. By fitted to the lattice constants, the cohesive energy, the APE (anti-phase boundary) energy, and the vacancy formation energy of TiAl, an accurate MEAM potential is obtained for the TiAl system with L10 structure. The calculation results of the properties of TiAl are in good agreement with experiments and the results of first principle (F.P.) calculations.

关键词： embedded atom method TiAl alloy angular dependence potential intermetallics

Application of the annexation principle to the thermodynamic property study of ternary metallic melts In-Bi-Cu and In-Sb-Cu

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Journal of University of Science and Technology beijing 2002年第3期9卷 170-176页

作者： Man ZhangMetallurgy School, University of Science and Technology beijing, beijing 100083. China (Received 2001-10-27) Metall. Sch. Univ. of Sci. and Technol. Beijing Beijing 100083 China

Based on the phase diagrams, measured activities and the annexationprinciple, calculating models of mass action concentrations for In-Bi-Cu and In-Sb-Cu melts havebeen formulated. Calculated results not only agree well with practical values, but also obey themass action law, showing that the deduced model can reflect the structural reality of given meltasand that the annexation principles is applicable to these tow ternary metallic melts. So long asthere is one from three binary systems constituting the ternary melts, in which the activities ofone component exhibit positive deviation relative to Raoultian behavior, heterogeous meltsinevitably would form, so heterogeneous calculating model should be used to calculate their massaction concentrations. On the contrary, if all the binary melts are homogeneous and their activitiesexhibit negative deviation with respect to the Raoult's law, then the ternary melts formed fromthem will certainly be homogeneous, hence single phase model should be applied.

关键词： activity mass action concentration coexistence theory annexationprinciple

Mechanism for calcite dissolution and its contribution to development of reservoir porosity and permeability in the Kela 2 gas field,Tarim Basin,China

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Science China Earth Sciences 2008年第4期51卷 567-578页

作者： YU BingSong1,3. DONG HailLiang2,3.& RUAN Zhuang1,3.1 State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, beijing 100083. China 2 Department of Geology, Miami University,Oxford, OH 45056, USA 3.Geomicrobiology Laboratory, China University of Geosciences, beijing, 100083. China State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Department of Geology Miami University Geomicrobiology Laboratory China University of Geosciences

This study is undertaken to understand how calcite precipitation and dissolution contributes to depth-related changes in porosity and permeability of gas-bearing sandstone reservoirs in the Kela 2 gas field of the Tarim Basin, Northwestern China. Sandstone samples and pore water samples are col-lected from well KL201 in the Tarim Basin. Vertical profiles of porosity, permeability, pore water chem-istry, and the relative volume abundance of calcite/dolomite are constructed from 3.00 to 4000 m below the ground surface within major oil and gas reservoir rocks. Porosity and permeability values are in-versely correlated with the calcite abundance, indicating that calcite dissolution and precipitation may be controlling porosity and permeability of the reservoir rocks. Pore water chemistry exhibits a sys-tematic variation from the Na2SO4 type at the shallow depth (3.00-3.3. m), to the NaHCO3.type at the intermediate depth (3.3.―3.95 m),and to the CaCl2 type at the greater depth (3.28―3.3. m). The geochemical factors that control the calcite solubility include pH, temperature, pressure, Ca2+ concen-tration, the total inorganic carbon concentration (ΣCO2), and the type of pore water. Thermodynamic phase equilibrium and mass conservation laws are applied to calculate the calcite saturation state as a function of a few key parameters. The model calculation illustrates that the calcite solubility is strongly dependent on the chemical composition of pore water, mainly the concentration difference between the total dissolved inorganic carbon and dissolved calcium concentration (i.e., [ΣCO2] -[Ca2+]). In the Na2SO4 water at the shallow depth, this index is close to 0, pore water is near the calcite solubility. Calcite does not dissolve or precipitate in significant quantities. In the NaHCO3.water at the intermedi-ate depth, this index is greater than 0, and pore water is supersaturated with respect to calcite. Massive calcite precipitation was observed at this depth interval and

关键词： calcite dissolution porosity thermodynamic Tarim Basin

Trend,seasonal and diurnal variations of atmospheric CO_2 in beijing

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Chinese Science Bulletin 2002年第24期47卷 2050-2055页

作者： WANG Yuesi, WANG Changke, GUO Xueqing, LIU Guangren & HUANG YaoLAPC, Institute of Atmospheric Physics, Chinese Academy of Sciences, beijing 100083. China Department of Chemistry, Capital Normal University, beijing 10003., China LAPC Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China Department of Chemistry Capital Normal University Beijing China

The concentration of atmospheric CO2 in beijing increased rapidly at a mean growth rate of 3.7%·a-1 from 1993.to 1995. After displaying a peak of (409.7±25.9) μmol·mol-1 in 1995, it decreased slowly. Both the almost stable anthropogenic CO2 source and increasing biotic CO2 sink contribute to the drop of CO2 concentration from 1995 to 2000. The seasonal variation of CO2 concentration exhibits a clear cycle with a maximum in winter, averaging (426.8± 20.6)μmol·mol-1, and a minimum in summer, averaging (3.9.1±6.1)μmol·mol-1. The seasonal variation of CO2 concentration is mainly controlled by phenology. The mean diurnal variation of atmospheric CO2 concentration for a year in beijing is highly clear: daily maximum CO2 concentration usually occurs at night, but daily minimum CO2 concentration does in the daytime, with a mean diurnal difference more than 3..7μmol·mol-1. It has been revealed that the interannual variations of atmospheric CO2 concentration in winter and autumn regulated the

关键词： atmospheric CO2 annual variation seasonal variation diurnal variation urban environment.