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Anisotropic Variation Law of Rock Permeability with the Burial Depth of Limestone

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Acta Geologica Sinica(English Edition) 2003年第1期77卷 125-128页

作者： TIAN Kaiming, WAN Li and TIAN Jiping Department of Water Resources and Environmental Science, china university of Geo{2.,2. Xueyuan Road, {4. 100083, Department of Computer {2., Guangzhou university, Guangzhou, Guangdong 510091 china Univ Geosci Dept Water Resources & Environm Sci Beijing 100083 Peoples R China Guangzhou Univ Dept Comp Sci Guangzhou 510091 Guangdong Peoples R China

Permeability tensors of both macrofracture and microfracture Systems weremeasured progressively along the depth of limestone formations at severed sites. It was found thatthe principal permeability values K_x, K_y and K_z in these permeability tensors all decreasesimultaneously and logarithmically with depth. However, the limestone aquifers are composed of anupper region where the larger permeability ellipsoid is upright or prolate and characterized byK_z>K_x and K_z>K_y, a transitional zone, and a lower zone whose smaller permeability ellipsoid ishorizontal or oblate and characterized by K_z>K_x and K_z>K_y. The inversion of the permeabilityellipsoids in direction indicates that the anisotropy of rock permeability with the depth oflimestone formations has evidently changed. The anisotropic variation law of permeability tensors ina macrofracture system displays a similar pattern with that in a microfracture system. It is nextto impossible to examine the rock permeability tensor of the aquifer just by measuring the hydraulicparameters of macrofracture system directly, unless the limestone aquifer is exposed on or near theearth's surface. Therefore, the permeability tensors of a macrofracture system at any depth may beindirectly and roughly determined from the gaugeable permeability tensors of the microfracturesystem by conversion. This anisotropic variation law of rock permeability with depth is of greatsignificance in the study of three-dimensional fracture water flow the huge carbonate formations andin the research on the conditions of karst development and karst distribution.

关键词： macrofracture system microfracture system permeability tensor permeability ellipsoid

Fracture characteristics of concrete subjected to impact loading

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Science china(Physics,Mechanics & Astronomy) 2010年第9期53卷 253-261页

作者： LIU HaiFeng1,2.LIU HaiYan3 & SONG WeiDong1 1 State Key Laboratory of Explosion Science and Technology,beijing Institute of Technology,beijing 100081,{2. 2.School of Civil and Hydraulic Engineering,Ningxia university,Yinchuan 75002.,{2. 3 School of Science,beijing Institute of Technology,beijing 100081,{2. 1. State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology Beijing 100081 China2. School of Civil and Hydraulic Engineering Ningxia University Yinchuan 750021 China3. School of Science Beijing Institute of Technology Beijing 100081 China

This paper takes concrete as a four-phase composite made of the intact matrix and three mutually perpendicular groups of penny-shaped micro-cracks. The intact matrix is assumed to be elastic,homogeneous and isotropic,and the micro-cracks are penny-shaped. Combined with the failure mechanism of concrete subjected to impact loading,a dynamic constitutive model for concrete is developed based on Mori-Tanaka's average stress concept and Eshelby's equivalent inclusion theory. Experimental results show that concrete is rate-dependent. The model predictions are in good agreement with the experimental results. The model may be used to simulate the mechanical behavior of concrete under impact loadings.

关键词： concrete micromechanics impact loading constitutive model

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Effect of annealing on composition,structure and electrical properties of Au layers grown on different thickness Cr layers

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Journal of university of Science and Technology beijing 2004年第3期11卷 235-239页

作者： Yan Huang Hong Qiu Liqing Pan Yue Tian Fengping Wang Ping Wu Department of Physics, Applied Science School, university of Science and Technology beijing, beijing 100083, china Dept. of Phys. Appl. Sci. Sch. Univ. of Sci. and Technol. Beijing Beijing 100083 China

110 nm-thick Au layers were sputter-deposited on unheated glasses coatedabout a 10 nm-thick and a 50 nm-thick Cr layer respectively. The Au/Cr bilayer films were annealedin a vacuum of 1 mPa at 300℃ for 2. 5 and 30 min, respectively. Auger electron spectroscopy, X-raydiffraction and Field emission scanning electron microscopy were used to analyze the composition andstructure of the Au layers. The resistivity of the bilayer films was measured by using four-pointprobe technique. The adhesion of the bilayer films to the substrate was tested using tape tests. Theamount of Cr atoms diffusing into the Au layer increases with increasing the annealing time,resulting in a decrease in lattice constant and an increase in resistivity of the Au layer. Thecontent of Cr inside the Au layer grown on the thinner Cr layer is less than that grown on thethicker Cr layer. For the Au/Cr bilayer films, the lower resistivity and the good adhesion to theglass substrate can be obtained at a shorter annealing time for a thinner Cr layer.

关键词： Au/Cr bilayer film Cr layer thickness annealing characteristic

Performance evaluation of oil displacing agents for primary-minor layers of the Daqing Oilfield

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Petroleum Science 2011年第1期8卷 79-86页

作者： Zhang Jian Wang Shuxia Lu Xiangguo He Xianhua School of Petroleum Engineering China University of PetroleumBeijing 102249China School of Petroleum Engineering Northeast Petroleum UniversityDaqingHeilongjiang 163318China Information Section E＆D Research Institute of Daqing OilfieldDaqingHeilongjiang 163712China

A series of experiments were conducted to investigate the molecular coil dimension（D_h） and molecular configuration of partially hydrolyzed polyacrylamides（HPAM）,surfactant/HPAM system, and a living *** between the polymer coils and the porous media was evaluated by instrumental analysis and laboratory simulation ***,the performance of chemical flooding was *** indicated that the D_h decreased with an increase in water salinity and increased with an increase in polymer *** aqueous solution,the polymer presented three-dimensional reticular configuration and exhibited a fractal structure characterized by self-similarity. The polymer in the surfactant/HPAM system was mainly in the form of＂surfactant-polymer＂complex compound and the living polymer had an irregular＂flaky-reticular＂configuration which resulted in relatively poor compatibility between the molecular coils and the porous *** type of oil displacing agent and its slug size influenced the incremental oil *** the same oil displacing agent,a larger slug size would lead to a better chemical flooding *** the final recovery efficiency and economic benefits,high-concentration polymer flooding was selected as the optimimal enhanced oil recovery（EOR） technique and the incremental recovery efficiency was forecast to be 2.%.

关键词： Primary-minor layers molecular coil dimension molecular configuration compatibility

Effect of Preparation Condition on Low-density PS Particle Size and Distribution

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Journal of university of Science and Technology beijing 2001年第4期8卷 274-276页

作者： Huili Fan, Jiemin Liu, Meijuan Wen, Weixue Tian Applied Science School. university of Science and Technology beijing.beijing 100083. china Univ Sci & Technol beijing Appl Sci Sch Beijing 100083 Peoples R China

The preparation conditions were studied in order to obtain smaller, narrow size-distributed and low-density polystyrene (PS) micro-particles by suspension polymerization. The results show that some of preparation conditions, the shape and position of stirrers, and stirring rate etc., have important influence on the size and distribution of particles. The preparation conditions must be carefully designed and controlled in order to obtain high-quality PS beads. A bow-shaped stirrer is helpful to produce small-sized particles and narrow size distribution, and the upper edge of a stirrer should be set to the same level as the surface of mixture, and the stirring rate should be controlled in the range of 52.-600 r/min.

关键词： low-density micro-particles suspension polymerization preparation conditions

Direct Synthesis and Spectrum Analysis of CeO_2.Nanoparticles Deposited on Carbon Nanotubes

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Journal of Wuhan university of Technology(Materials Science) 2009年第1期24卷 34-37页

作者：张祖伟胡陈果 Department of Applied Physics Chongqing University

A novel method of direct synthesis of CeO2.nanoparticles onto multi-walled carbon nanotubes （MWNTs） was developed with advantages of simplicity, ease of scale-up, and low costs. The size of CeO2.particles deposited on the MWNTs was less than 6 nm. SEM and TEM were em-ployed to analysis the CeO2.coated MWNTs, and the properties of FTIR spectrum and UV-vis ab-sorption spectrum were investigated. The functional groups on the MWNTs obtained by nitric acid treatment play an important role on the deposition of the CeO2.particles. The carbon nanotubes possess broadened UV absorption function after being coated with CeO2.nanopartilces.

关键词： nanocomposites chemical synthesis spectrum

DEPOSITIONAL SEQUENCES AROUND J/K BOUNDARY IN THE QOMOLONGMA AREA, SOUTH TIBET

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地学前缘 2000年第S1期7卷 21-22页

作者： Shi Xiaoying 1, Nicol Morton 2.1 china university of Geo{2., {4. 100083,china 2.university of London, London WC1E 7HX,UK)

The uppermost Jurassic to Lower Cretaceous in the Qomolongma (Mt. Everest) area were deposited in a strong subsiding setting on passive continental margin. From Tithonian to Valanginian, the area experienced an environment shift from circum\|shelf margin carbonate platform to foreslope, then to deep continental slope [1] . Correspondingly, the sediments change in vertical succession from quartz sandstone, via carbonate grainstone to dark shale intercalated with lithic sandstone of gravity flow. From the Tithonian to Valanginian, eight 3rd\|order sequences have been recognized [1] with clearly delineated sequence boundaries and reasonable biostratigraphic controls of ammonites. From the angle of sequence stratigraphy and sedimentary cycles, the important change happened at ca. 138Ma [2. of the Lower Tithonian (about 12.m above Aulacosphinctoides hybonotum zone), where a waved subaerial erosion surface occurs in massive bioclastic grainstone. The boundary at ca. 134.5Ma (latest Tithonian, about 60m below the FAD of \%Berriasella cf. jacobi [3] ) comes to the next. The third one is at ca 132.a (some 170m above the FAD of Berriasella cf. jacobi [3] , but about 60m below the FAD of Berriasella cf. grandis [3] ). In terms of sea\|level change, the sequence boundary at 134.5Ma is probably the most distinctive one, above which some 60m gravel\|bearing massive medium\|grained quartz sandstone was laid down and obviously truncates the underlying strata. In the dark shale below the sandstone, abundant in ammonites, such as Virgatosphinctes, Aulacosphinctes, Haplophylloceras and Gymnosphinctes are recorded [3] . The quartz sandstone itself does not bear identifiable fossils. Above the quartz sandstone, the strata mainly consists of dark silty shale up to 180m thick, with an prominent marine transgression at the base. Just above the first flooding surface (FFS), quite a number of ammonites such as \%Berriasella\% cf. \%jacobi, Blanofordiceras, Hymalayaites\% and \%Pseudosubplani

关键词： J/K boundary depositional sequences South Tibet

DTA INVESTIGATION OF CRYSTALLIZATION BEHAVIOUR IN SrO-TiO_2.SiO_2.GLASS-CERAMICS

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Journal of Wuhan university of Technology(Materials Science) 1995年第2期10卷 11-16页

作者：谢为民丁振亚 Wuhan Univ of Technology China

The crystallization process of STS glass-ce-ramics was carried out in a constant temperature. The glass-ceramics still show good piezoelectric properties. The mecha-nism of orientation crystallization was investigated... 详细信息

关键词： SrO-TiO2.SiO2.glass-ceramics crystal-lization

Heterogeneous reactions of SO_2.on ZnO particle surfaces

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Science china Chemistry 2011年第1期54卷 161-166页

作者： LI Jia,SHANG Jing & ZHU Tong State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental sciences and Engineering,Peking university,{2. 100871,china 1. State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental sciences and Engineering Peking University Beijing 100871 China

Heterogeneous reactions of SO2.on ZnO particle surfaces were studied using in situ diffuse reflectance infrared Fourier transform spectroscopy （DRIFTS）. The influences of relative humidity （RH） and UV radiation （2. 365 nm） were investigated. In the absence of UV radiation, sulfite was the prominent product on the particle surfaces, and a negative relationship between RH and sulfite production was observed. In the presence of UV radiation, infrared （IR） absorption of sulfite and sulfate was evident in the spectra. With increasing RH or UV intensity, sulfite was gradually transformed into sulfate. UV intensity and RH exhibited a synergistic effect on the heterogeneous oxidation of SO2.on ZnO. On dry particles and with no UV radiation, the reaction order of SO2.on ZnO particles was 1.6. The initial uptake coefficient for the formation of sulfite, using the Brunauer-Emmett-Teller （BET） area as the reactive surface area of SO2. was 4.87 × 10^-6. At 4.% RH and with UV radiation, the reaction order was 0.91, and the initial uptake coefficient was 2.2. ×10^-5.

关键词： SO2 ZnO DRIFTS heterogeneous oxidation UV radiation