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Rock matrix-fractured media model for heterogeneous and fractured coal bed

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中国有色金属学会会刊：英文版 2011年第S3期21卷 621-625页

作者： ZHANG Chun-hui1, YU Guang-ming2. ZHANG Chun1 1. School of Civil engineering, Hebei University of science and {2., Shijiazhuang 050018, china 2. School of Civil engineering, Qingdao Technological University, Qingdao 2.6033, china [a] School of Civil engineering Hebei University of Science and Technology Shijiazhuang 050018 China [b] School of Civil engineering Qingdao Technological University Qingdao 266033 China

Coal was considered rock matrix-fractured media composed of rock matrix and fractures, and the rock matrix-fractured media model for heterogeneous and fractured coal bed was presented. In this model the rock matrix is heterogeneous, and the mechanical parameters such as elastic modulus and strength follow Weibull distribution. Fractures in coal bed were generated with the discrete fracture network method, and the properties of fractures were simulated with Desai element. Then the virtual generating system (VGS) of natural heterogeneous and fractured coal bed was developed in Matlab 6.0. The coupled model of gas flow and deformation process based on the rock matrix-fractured media model method and VGS for heterogeneous and fractured coal bed was presented, and the numerical code was developed in Matlab 6.0. The gas flow process in the heterogeneous and fractured coal bed was simulated in a numerical case. The main conclusions are: 1) The natural heterogeneous and fractured coal bed could be simulated by the rock matrix-fractured media model and VGS; 2. The fractures connected with the well have much more effects on gas flow than those non-connected.

关键词： heterogeneity fractures rock matrix-fractured media

Photocatalytic Degradation of Rhodamine B Dye with MWCNT/TiO_2.C_(60) Composites by a Hydrothermal Method

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Journal of wuhan University of technology(Materials {2.) 2011年第1期26卷 65-69页

作者：史晓亮 School of Mechanical and Electronic engineering Wuhan University of Technology State Key Laboratory of Advanced technology for Materials Synthesis & Processing Wuhan University of Technology

Multi-walled carbon nanotube （MWCNT）/TiO2.C60 composite catalysts were prepared by hydrothermal method. TiO2.was deposited on the MWCNT surface. Their photocatalytic activities for degradation of Rhodamine B dye were studied. X-ray diffraction, field emission transmission electron microscopy, ultraviolet-visible light absorption spectrum and photoluminescence spectrum were carried out to characterize the composite catalysts. The results indicated that MWCNTs and C60 could greatly enhance the photocatalytic activity of TiO2.

关键词： semiconductors chemical synthesis optical properties surface properties

CAD/CAE OF THE WORKING CHARACTERISTICS OF A NEW TYPE OF FLUID COUPLING SHOCK ABSORBER

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Chinese Journal of Mechanical engineering 2002年第3期15卷 222-227页

作者： Yang Ping Zhong Yifang Zhou JiSchool of Mechanical science and engineering, {2. University of science and technology,wuhan 43.074, chinaLiu Yong Guilin institute of Electronic technology *** School of Mechanical science and engineering Huazhong University of Science and Technology Wuhan 430074 China

For purpose of simulation of the working characteristics of a new type offluid coupling shock absorber for vibration protection of sensitive equipment, a physical model ispresented by analyzing the internal fluid dynamic phenomenon with respect to the coupling shockabsorber and implemented in MATLAB software package. Using the model it is possible to evaluate theimportance of different factors for design of the shock absorber. In the meantime, the key-modelmachine is designed for coupling dynamic test. Comparisons with experimental results confirm thevalidity of the model. So the CAD/CAE software has been developed in MATLAB for design andexperimental test of the new coupling shock absorber.

关键词： Fluid coupling shock absorber Working characteristics Model Simulation

Relationship between Retrographical and Physical Properties of Aggregates

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Journal of wuhan University of technology(Materials {2.) 2010年第4期25卷 678-681页

作者：庞凌 School of sciences Wuhan University of Technology

The relationship between petrographical and physical properties of limestone, basalt, granite and gneiss was investigated. Petrographical data were quantified from polished thin sections with a polarising microscope to determine the modal composition. The properties of resistance to fragmentation and abrasion were determined by Los Angeles abrasion test and crushing test. The shape characteristic was measured by Flakiness index test. The experimental results indicate that abundance of fineto medium-grained minerals （especially of plagioclase, quartz and feldspar） are prime, and strong micrographic intergrowth texture with interlocking grain boundaries have the great positive influence on the physical properties. It is also indicated that petrographical properties and surface texture of rocks can decide the potentiality of rocks as raw materials with high quality on resisting fragmentation and abrasion. Analysis of Integration of petrographical data and mechanical properties is ideal for the selection of aggregates used in asphalt concrete.

关键词： aggregate petrography physical properties flakiness index

On degrees of freedom of the cellular network

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science china(Information sciences) 2010年第05期53卷 1034-1043页

作者： SUN Jun 1,2., LIU YingZhuang 1,2.& ZHU GuangXi 1,2.1 Department of Electronics and Information engineering, huazhong University of {2. and technology, wuhan 43.074, china 2.Division of Optical Network and Intelligent Communication, wuhan National Laboratory for Optoelectronics, wuhan 43.074, china 1. Department of Electronics and Information engineering Huazhong University of Science and Technology Wuhan 430074 China2. Division of Optical Network and Intelligent Communication Wuhan National Laboratory for Optoelectronics Wuhan 430074 China

In this paper, we consider the capacity limits of the cellular network by modeling it as consisting of two mutually interfering multiple access channels with multiple antennas at each receiver (e.g., base station). By developing a tight outerbound as well as an achievable scheme which exploits the idea of interference alignment, we are able to exactly characterize the sum degrees of freedom (DoF) of the network when the channel coefficients are timeor frequency-varying, which equals KM K+min(M,K) (where M and K denote the number of receiver antennas and number of users in per cell, respectively) per cell. From the DoF result, it can be observed that in addition to the multi-user gain which has been reported for the network with single-antenna BSs, there also exists the multi-antenna gain in the cellular network. In particular, when the number of users is large, we can nearly achieve the interference-free DoF of a cellular network with multiple-antenna BSs, which is a somewhat surprising result.

关键词： capacity degrees of freedom cellular network interference alignment interference channel MIMO

Effects of Al on Microstructure and High-Temperature Wear Properties of Austenitic Heat-Resistant Steel

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Journal of Iron and Steel Research International 2012年第3期19卷 62-66页

作者： ZHANG Yan1, SUN Yu-fu2. ZHAO Jing-yu2. GUAN Shao-kang2.(1. School of Materials engineering, Nanjing institute of {2., Nanjing 2.1167, Jiangsu, china 2. School of Materials science and engineering, Zhengzhou University, Zhengzhou 450002. Henan, china) [a] School of Materials engineering Nanjing Institute of Technology Nanjing 211167 Jiangsu China [b] School of Materials science and engineering Zhengzhou University Zhengzhou 450002 Henan China

Microstructure and high-temperature dry sliding wear at 600 ~C in ambient air of austenitic heat-resistant steel ZG40Cr2.Ni2. with different contents （mass percent） of AI （0 to 7.10~） have been investigated. The results show that microstructures of 4.68% and 7.10% A1 addition content consist of the matrix and reinforcement of inter- metallic compound y＇ and carbide, while microstructures of ZG40Cr2.Ni2. without A1 and with A1 of 1.68% are ab- sent of y＇. Higher wear resistance than the original ZG40Cr2.Ni2. alloy is achieved in alloys with higher content of A1 under the same high-temperature wear test condition. The wear rates of Fe-2.Cr-2.Ni-7.10A1 and Fe-2.Cr-2.Ni- 4.68A1 are only 2..83% and 45.83% of that of Fe-2.Cr-2.Ni, respectively. Heat-resistant steels with higher con- tents of AI （4.72. and 7.10%） have higher hardness than those with lower contents of AI （1.68% and 0）. Wear mechanisms of ZG40Cr2.Ni2. are considered as severe plough plastic deformation and slight adhesive. However, wear mechanisms of Fe-2.Cr-2.Ni 4.68A1 are light micro-cutting and oxidation-wear, while that of Fe-2.Cr-2.Ni- 7. 10A1 are severe adhesive transfer and oxidation-wear_

关键词： austenitic heat resistant steel Al microstructure high-temperature sliding wear mechanism

Electrophoretic Coating of Hydroxyapatite on Pyrolytic Carbon Using Glycol as Dispersion Medium

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Journal of wuhan University of technology(Materials {2.) 2008年第3期23卷 293-297页

作者：高林 College of Life science and technology Huazhong University of Science and Technology College of Chemistry and Environmental engineering Yangtze UniversityJingzhou 434023China

Hydroxyapatite （HA） coatings on pyrolytic carbon were produced via electrophoretic deposition （EPD） using glycol and ethanol as dispersion medium respectively. The effect of the solubility of HA in the dispersion medium on crack occurrence and adherence of the coating was investigated by means of scanning electronic microscope （SEM） and atomic absorption spectrometer （AAS）. The results show that the solubility of HA in glycol is higher than that in ethanol. The usage of glycol as a dispersion medium can reduce the possibility of crack formation and enhance the adhesive strength between the coating and the carbon substrate. The green coatings can be sintered under vacuum at 1 000 ℃ whether the coatings are obtained using ethanol or glycol as dispersion medium. No HA decomposition was observed up to 1 000 ℃ by vacuum sintering by X-ray diffraction （XRD） analysis.

关键词： hydroxyapatite electrophoretic deposition coatings dispersion medium glycol

Synthesis and Characterization of Ibuprofen-Rectorite Composites by Solution Intercalation Method

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Journal of wuhan University of technology(Materials {2.) 2009年第4期24卷 654-657页

作者：王慧燕 Hospital Wuhan University of Teehnology

The ibuprofen-rectorite composites were prepared by the solution intercalation method using ibuprofen and rectorite as raw materials, and were characterized by X-ray diffraction （XRD） analysis, Fourier transform infrared analysis and scanning electron microscopy （SEM）. The experimental results show that the ibuprofen is intercalated into the interlayer spaces of rectorite. The values of the （001） peaks of the ibuprofen-rectorite composite are larger than that of Na-rectorite and reach the largest when the reaction time and ibuprofen amount is 2.h and 0.36 g, respectively. The layered structure of Na-rectorite is destroyed to some extent with the intercalation of ibuprofen into the interlayer space in the structure of Na-rectorite. A part of ibuprofen in the ibuprofen Na-rectorite covers on the surface of Na-rectorite besides some ibuprofen enters into the interlayer space.

关键词： ibuprofen rectorite solution intercalation composites clay

Early Age Hydration of Cement Paste Monitored with Ultrasonic Velocity and Numerical Simulation

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Journal of wuhan University of technology(Materials {2.) 2010年第4期25卷 704-707页

作者：陈伟 Key Laboratory of Silicate Materials science and engineering Ministry of EducationWuhan University of Technology School of Materials science and engineering Wuhan University of Technology

Early age hydration of cement paste was investigated by monitoring the ultrasonic propagation velocity and simulated with the numerical model CEMHYD3D. The ultrasonic velocity of the P-wave was recorded during the first 2. hours of the hydration process and its evolution was analyzed. It is shown that the UPV method is an effective, accurate and non-destructive method for monitoring the early age hydration process of cement paste. The early age hydration process can be classified as four periods, which are the dormant period, acceleration period, deceleration period and stabilization period. Higher w/c ratios result in lower UPV, and delay initial setting time due to the decreased solid volume. The change of UPV is clearly related to the hydration degree of cement particles.

关键词： early age hydration ultrasonic velocity hydration degree CEMHYD3D