检索结果-南通市图书馆

Fractal Characteristics of Coal Pores Based on Classic Geometry and Thermodynamics Models

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2011年第5期85卷 1150-1162页

作者： CAI Yidong~1,LIU Dameng~(1,*),YAO Yanbin~1,LI Junqian~1 and LIU Junlai~2 1 School of Energy Resources,china university of geosciences,{3. {4.china 2 School of Earth Science and Resources,china university of geosciences,{3. {4.china School of Energy Resources China University of Geosciences Beijing 100083 China School of Earth Science and Resources China University of Geosciences Beijing 100083 China *Correspondence: Dameng LIU *Correspondence: Corresponding author. E-mail: dmliu@***

To better understand the characteristics of coal pores and their influence on coal reservoirs, coal pores in eight main coalfields of North china were analyzed by mercury porosimetry and scanning electron microscopy（SEM）.Fractal characteristics of coal pores（size distribution and structure） were researched using two fractal models:classic geometry and *** two models establish the relationship between fractal dimensions and coal pores *** results include:（1） SEM imaging and fractal analysis show that coal reservoirs generally have very high heterogeneity;（2） coal pore structures have fractal characteristics and fractal dimensions characteristic of pore structures are controlled by the composition（e.g.,ash,moisture,volatile component） and pore parameters（e.g.,pore diameter,micro pores content） of coals;（3. the fractal dimensions（D;and D;） of coal pores have good correlations with the heterogeneity of coal pore *** fractal dimensions correlate to higher heterogeneity of pore *** fractal dimensions（D;and D;） have strong negative linear correlations with the sorted coefficient of coals （R;=0.719 and 0.63.,respectively） that shows the heterogeneity of coal pores;（4. fractal dimension D;and petrologic permeability of coals have a strong negative exponential correlation（R;=0.82）.However, fractal dimension D;and petrologic permeability of coals have no obvious correlation;and（5） the model of classic geometry is more accurate for fractal characterization of coal pores in coal reservoirs than that of thermodynamics by optimization.

关键词： coal pores mercury porosimetry fractal dimensions thermodynamics model classic geometry model

The Dynamic Mechanisms for the Formation of Primary Metal Zoning of Cassiterite-Sulfide Deposits in the Gejiu Metallogenic Province, Yunnan

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 1991年第1期65卷 51-63页

作者： Yu Chongwen Jiang Yaosong china university of geosciences, {3. china university of geosciences Beijing

Copper and tin in cassiterite-sulfide deposits of the Gejiu metallogenic province are intimately associatedand show peculiar primary metal zoning. The authors made use of computer techniques to simulatenumerically the zoning of these ore deposits. The study shows that the regular spatial zoning probably resultedfrom the succession of multiple, intermittent and pulsatory mineralizations, The successive transports with di-verse velocities along channelways of the ore-forming solutions, taking place under conditions of definite dif-ference between metal concentrations, in solutions and wallrocks, followed by differential deposition, consti-tute possible dynamic mechanisms for the primary metal zoning.

关键词： Met rate The Dynamic Mechanisms for the Formation of Primary Metal Zoning of Cassiterite-Sulfide Deposits in the Gejiu Metallogenic Province Yunnan

Calculating model of mass action concentrations for Ag-Au-Cu melts

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2002年第1期21卷 43-47页

作者： ZHANG Jian Metallurgy School, university of Science and Technology beijing, beijing 100083. china Metallurgy School University of Science and Technology Beijing 北京 100083

Based on phase diagrams and measured activities, the calculatingmodel of mass action concentrations for het- erogeneous meltsAg-Au-Cu was formulated. Calculated results agree with the improvedresults of recent research work, Showing that the model formulatedcan reflect the structural characteristics of these melts. In thismodel, without the help Of any empirical parameters, only threeequilibrium constants are used, hence it is simple, lear, andfavorable to the sim- Plification of calculation.

关键词： activity mass action concentration eutectic Solid solution

Progress in researching into the transition of the Mesozoic tectonic systems in southeast china

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2006年第6期16卷 563-572页

作者： YU Xinqi, WU Ganguo, ZHANG Da, ZHANG Xiangxin, DI Yongjun, ZANG Wenshuan, WANG Qunfeng and HUANG Huojian (State Key Laboratory of Geological Processes and Mineral Resources, china university of geosciences,{3. Key Laboratory of Lithosphere Tectonics and Lithoprobing Technology of Ministry of Education, china university of geosciences,{3.) [a] State key Laboratory of Geological Processes and Mineral Resources Chine University of Geosciences Beijing China [b] Key Laboratory of Lithosphere Tectonics and Lithoprobing Technology of Ministry of Education China University of Geosciences Beijing China

This paper presents the latest progress made on the research of Mesozoic tectonic system transition from the E-W paleo-Tethyan tectonic domain into NE-NNE western Pacific domain in southeast china. Tectonism of the west Pacific domain began at middle Jurassic (J2) and formed a set of NE-trending structures, non-coaxially overprinting on E-trending tectonic belts which may be early and coevally produced by the paleo-Tethyan domain. Thus began the tectonic domain transition from the E-trending paleo-Tethyan to the NE-trending Pacific and fully finished at the early Cretaceous. The eastern Nanling area was a junction zone of the transition at middle Jurassic (J2),and ever since the junction zone might obliquely migrate to the coastal region, where is the east part of this study area. To the north of the Nanling area, the Ganjiang Fault Zone was the boundary between two tectonic domains. Corresponding to the transition of tectonic system, the geodynamics of SE china changed from a compressional system to an extensional system, which continued until the end of Mesozoic-Tertiary.

关键词： transition of tectonic system non-coaxial overprint obliquely migrate Mesozoic paleo-Tethyan tectonic domain west Pacific tectonic domain southeast china.

Research advances in the Mesozoic tectonic regimes during the formation of Jiaodong ore cluster area

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2006年第8期16卷 777-784页

作者： DENG Jun, YANG Liqiang, GE Liangsheng, WANG Qingfei, ZHANG Jing, GAO Bangfei, ZHOU Yinghua and JIANG Shaoqing (State Key Laboratory of Geological Processes and Mineral Resources, china university of geosciences,{3. Key Laboratory of Lithosphere Tectonics and Lithoprobing Technology of Ministry of Education, china university of geosciences,{3.) [a]State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Beijing China [b]Key Laboratory of Lithosphere Tectonics and Lithoprobing Technology of Ministry of Education China University of Geosciences Beijing China

Based on research advances of the tectonic regime in Jiaodong ore cluster area and the related tectonic regime transformation in Mesozoic era in the eastern region of North china, in this paper, we first summarize some key problems required to be studied further on. Then we suggest an approach to dealing with these problems. It is known that the gold deposits in Jiaodong ore cluster area, which are of different mineralization styles, spatial distributions and geological settings, might be as a result from one or more geologic events in Mesozoic. Till now, this kind of research on the temporal evolution and spatial migration sequence, especially on the geodynamic mechanism of the above events, is far from sufficient. Moreover, quantitatively describing the action mode and the temporal-spatial framework of tectonic dynamic regimes and formulating the relative contribution of every tectonic dynamic regime for the metallogensis are still challenges to the geologists studying on the formation of Jiaodong ore cluster area. According to the interpretation of the regional tectonic analysis, the structural dynamics, the observation and the exploration of the mineralization network, we propose a geological-physical-chemical model with some constraints originated from the comprehensive analysis. We then use this model to simulate the coupled processes of the structural deformation, thermal transport, fluid flow and the chemical reaction. The obtained results indicate that the model is efficient in further analyzing the temporal-spatial evolutional trail of the tectonic regime in Jiaodong ore cluster area and in further understanding the nature of the mass metallogensis.

关键词： tectonic regime Mesozoic era Jiaodong ore cluster area genesis metallogenic system.

Role of inositol 1,4.5-trisphosphate receptors in α1-adrenergic receptorinduced cardiomyocyte hypertrophy

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Pharmacologica Sinica 2006年第7期27卷 895-900页

作者： Da-li LUO~(2,3.5) Jian GAO~2 Xiao-mei LAN~3.Gang WANG~4.Sheng WEI~4.Rui-ping XIAO~4.Qi-de HAN~3. Department of Pharmacology,School of Chemical Biology & Pharmaceutical Sciences,Capital university of Medical Sciences,{4. 100069,china 3.Institute of Cardiovascular Science at Health Science Center,Peking university {4. 100083.china 4.Institute of Molecular Medicine and College of Life Science,Peking university,{4. 100871,china Department of Pharmacology School of Chemical Biology & Pharmaceutical Sciences Capital University of Medical Sciences Beijing 100069 China Institute of Cardiovascular Science at Health Science Center Peking University Beijing 100083 China Institute of Molecular Medicine and College of Life Science Peking University Beijing 100871 China

Aim:Intracellular Ca2+plays pivotal roles in diverse cellular functions,includinggene transcription that underlies cardiac remodeling during stress ***,the role of inositol 1,4.5-trisphosphate receptors（IP3.s）in the media-tion of cardiac intracellular Ca2+and hypertrophic growth remains *** with neonatal rat ventricular myocytes suggests that activation of IP3.smay be linked to α1adrenergic receptor（α1AR）increased stereotyped Ca2+sparkoccurrence and global Ca2+***,we hypothesized that Ca2+releasethrough IP3.s was necessary for α1AR-stimulated cardiac ***:We used myoinositol 1,4.5-trisphosphate hexakis（butyryloxymethyl）ester（IP3.M）,a membrane-permeant ester of IP3.to activate IP3.s directly,and Fluo 4.AM tomeasure intracellular Ca2+***:IP3.M(10μmol·L-1)mimicked theeffects of phenylephrine,a selective agonist of α1AR,in increments in local Ca2+spark release（especially in the perinuclear area）and global Ca2+*** importantly,IP3. inhibitors,2-aminoethoxydiphenyl borateand Xestospongin C,abolished the IP3.M-induced Ca2+responses,and signifi-cantly suppressed α1AR-induced cardiomyocyte hypertrophy assayed by cellsize,[3.]leucine incorporation and atrial natriuretic factor gene expression,dur-ing sustained（4. h）phenylephrine ***:These results,therefore,provide cellular mechanisms that link IP3. signaling to α1AR-stimulatedgene expression and cardiomyocyte hypertrophy.

关键词： inositol 1,4.5-trisphosphate receptors Ca2+sparks α1 adrenergic stimulation cardiac hypertrophy

Role of gallium wetting layer in high-quality ZnO growth on sapphire (0001) substrates

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2004年第5期47卷 612-620页

作者： ZENG Zhaoquan1,3. WANG Yong2, DU Xiaolong1, MEI Zengxia1, KONG Xianghe3. JIA Jinfeng1, XUE Qikun1 & ZHANG Ze2, 4.1. State Key Laboratory for Surface Physics, Institute of Physics, Chinese Academy of Sciences, beijing 100080, china 2. Laboratory of Electron Microscopy, Institute of Physics, Chinese Academy of Sciences, beijing 100080, china 3. College of Physics and Engineering, Qufu Normal university, Qufu 273.65, china 4. beijing university of Technology, beijing 100022, china 1. State Key Laboratory for Surface Physics Institute of Physics Chinese Academy of Sciences 100080 Beijing China 2. College of Physics and Engineering Qufu Normal University 273165 Qufu China 3. Laboratory of Electron Microscopy Institute of Physics Chinese Academy of Sciences 100080 Beijing China 4. beijing university of Technology 100022 Beijing China

A Ga wetting layer was used to modify the surface structure of sapphire (0001) substrate to prepare high-quality ZnO film by radio frequency plasma-assisted molecule beam epitaxy. We found that this Ga layer plays a crucial role in eliminating 3. rotation domains, controlling polarity and decreasing defect density in ZnO epilayers, as demonstrated by in situ reflection high energy electron diffraction, ex situ high resolution X-ray diffraction and high resolution cross-sectional transmission electron microscopy. Zn-polar film of ZnO was determined by convergent beam electron diffraction. A Ga bilayer model is proposed to understand the effects of the Ga wetting layer on high-quality ZnO growth.

关键词： Ga wetting layer, sapphire, polarity, defect density, zinc oxide, rf-MBE, RHEED, HRXRD, TEM, CBED.

The evolution and morphological stability of a spherical crystal

在线全文

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2008年第3期51卷 225-243页

作者： CHEN MingWen1,2, WANG ZiDong2 & XU JianJun3.4.1 School of Applied Sciences, university of Science and Technology beijing, beijing 100083. china 2 School of Materials Science and Engineering, university of Science and Technology beijing, beijing 100083. china 3.School of Mathematical Sciences, Nankai university, Tianjin 3.0071, china 4.Department of Mathematics and Statistics, McGill university, Montreal H3. 2K6, Canada 1. School of Applied Sciences University of Science and Technology Beijing Beijing 100083 China 2. School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China 3. School of Mathematical Sciences Nankai University Tianjin 300071 China 4. Department of Mathematics and Statistics McGill University Montreal H3A 2K6 Canada

The growth model of a spherical crystal in the undercooled melt including the surface energy, interfacial kinetics and convective flow is established. The effect of the convective flow induced by a small far field flow on the evolution and morphological stability of the interface of the spherical crystal is studied. The interface shape of the spherical crystal, which is affected by the far field flow, and the dispersion relation of the growth rate of amplitude of the perturbed interface are derived. It is shown that the convection induced by the far field flow makes the interface of the growing spherical crystal further grow in the upstream direction of the far field flow and inhibit growth in the downstream direction; the interface of the decaying spherical crystal further decays in the upstream direction and inhibits decay in the downstream direction. The theoretical result suggests that both the growth of the sphere in the upstream direction and the decay of the sphere in the downstream direction make the spherical crystal tend to evolve into an oval; the morphological stability of the interface depends on a certain radius R c such that the spherical crystal is unstable when its radius is greater than R c and stable when its radius is less than R c . The surface energy and interfacial kinetics have strong stabilizing effects on the growth of the spherical crystal. In the meantime interfacial kinetics is a table factor of the interface when the interface of the sphere is growing; it is an unstable factor of the interface when the interface is decaying.

关键词： solid-liquid interface spherical crystal convective flow crystal growth morphological stability

The Depositional Environment of the Cretaceous Kizilsu Group in Xinjiang——With a Discussion of the Lowermost Marine Horizon of the Cretaceous in the Western Tarim Basin

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 1991年第4期65卷 441-453页

作者： Guo Xianpu china university of geosciences, {3. Sun Sheping china university of geosciences Beijing

In this paper. it is demonstrated that there exist marine horizons in the upper part of the lower subcycleand the upper subeycle of the Kizilsu Group in Xinjiang. based on new evidence of authigenic glauconite.boron content. carbon and oxygen stablc isotopic analyses. and lithological and sedimentary features. The up-per part of the lower subeycle is the lowermost marine horizon of the Cretaceous in the western Tarim Basin,which is inferred to be of Barremian age.

关键词： In With a Discussion of the Lowermost Marine Horizon of the Cretaceous in the Western Tarim Basin The Depositional Environment of the Cretaceous Kizilsu Group in Xinjiang