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Beijing Keji Daxue Xuebao/Journal of University of Science and Technology Beijing 2011年第6期33卷 682-687页

作者： Mo, Xiao-Lan Lin, Hai Dong, Ying-Bo Fu, Kai-Bin Xu, Cheng-Yan School of Civil and Environmental Engineering University of Science and Technology Beijing Beijing 100083 China Key Lab. of the Ministry of Education of China for High-Efficient Mining and Safety of Metal Mines University of Science and Technology Beijing Beijing 100083 China

In order to clarify the function of quartz in chalcopyrite bioleaching, quartz with particle sizes less than 43 μm was used to prepare a slurry system with chalcopyrite and pyrite for studying the effect of the mass concentration of quartz on the bioleaching efficiency of chalcopyrite. It is shown that the bioleaching of chalcopyrite can be improved by the addition of proper amount of quartz with finer particle sizes. Under the addition of 50 g·L-1 quartz whose particle size was less than 43 μm, the largest leaching rate of chalcopyrite is 54.09%. Based on the analysis of oxidation-reduction potential, pH values, Fe2+ and Fe3+ mass concentrations and the results of scanning electron microscopy and energy dispersive spectroscopy, quartz benefits the bioleaching of chalcopyrite, and this phenomenon mainly presents a decrease of bioleaching delay time. Moreover, new precipitates generated in the leaching process can be adsorbed by quartz, which reduces the hindrance of precipitation during chalcopyrite bioleaching.

关键词： Quartz

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Preparation and properties improvement of a novel ternary calcium phosphate cement system

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Gongneng Cailiao/Journal of Functional Materials 2011年第11期42卷 1931-1935页

作者： Gu, Tao Shi, Hai-Shan Ye, Jian-Dong School of Materials Science and Engineering South China University of Technology Guangzhou 510641 China Key Lab. of Specially Functional Materials and Advanced Manufacturing Tech. of Ministry of Education South China University of Technology Guangzhou 510641 China

Reinforced calcium phosphate cement (CPC) composed of three compartments was prepared by orthogonal test to improve the properties in this study. The effects of tetracalcium phosphate on the mechanical properties, setting time, phase evolution, microstructure, and exothermal behavior of CPC were systematically investigated. The results demonstrated that with the tetracalcium phosphate reacting lowly, the compress strength of CPC was enhanced remarkably. New content obviously increased the setting time, reduced the porosity and enhanced the compressive strength of CPC by about 50%, the exothermal peak during reaction dropped by 40% while cumulative heat liberation maintained constant. This ternary CPC system should be a promising material for bone repair and bone reconstruction.

关键词： Compressive strength

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Study on bioleaching of different types of chalcopyrite

Beijing Keji Daxue Xuebao/Journal of University of Science a...

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Beijing Keji Daxue Xuebao/Journal of University of Science and Technology Beijing 2011年第7期33卷 806-811页

作者： Fu, Kai-Bin Lin, Hai Mo, Xiao-Lan Dong, Ying-Bo Zhou, Li School of Civil and Environmental Engineering University of Science and Technology Beijing Beijing 100083 China Key Lab. of the Ministry of Education of China for High-Efficient Mining and Safety of Metal Mines University of Science and Technology Beijing Beijing 100083 China

Bioleaching of chalcopyrite with two different types, pyrite type and porphyry type, was compared. It is shown that there is a great difference in leaching efficiency. After 48 d, the copper leaching rate reaches 46.96% for the pyritic chalcopyrite, while it is 14.5% for the porphyry chalcopyrite. Based on the analysis of Fe2+, Cu 2p spectra on the chalcopyrite surface and deposit characteristics, a moderate amount of Fe2+ can promote bioleaching of the two kinds of chalcopyrite, but their optimal dosages are distinct. Different products appear on the surfaces of leached residues, and there is a copper-rich layer on the porphyry chalcopyrite, which hinders a greater copper extraction. Compared with the crude ore, Cu peak shift to lower binding energies was observed, following the leaching mechanism suggested by Hiroyoshi et al. the difference in bio-leaching between them is dependent on the integration of many factors such as metallogenic rock, wall rock, associated minerals and elements, metallogenic temperature and pressure.

关键词： Bioleaching

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Risk analysis of ground subsidence accidents caused by underground storage caverns in salt rock

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Yantu Lixue/Rock and Soil Mechanics 2011年第SUPPL.2期32卷 544-550页

作者： Jing, Wen-Jun Yang, Chun-He Kong, Jun-Feng Ji, Wen-Dong State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences Wuhan 430071 China Key Lab. for Exploitation of Southwestern Resources and Environmental Disaster Control Eng. Ministry of Education Chongqing University Chongqing 400044 China

In the construction and operation processes of underground storage cavern in bedded salt, ground subsidence, even earth surface collapse accidents, resulted by the storage cavern contraction and overlying rock deformation is an important accident type. Aimed at the ground subsidence accidents caused by underground storage cavern, this paper reveals the mechanism and builds the fault tree model of this type of accidents, finds out 14 failure patterns as well as 10 basic influence factors, also, puts forward the related control measures. Then Yunmeng-Yingcheng salt mine is taken as an example to forecast the severity of accident consequence. On the premise that ground subsidence accident happened at Yunmeng-Yingcheng salt mine, the severity probability of the accident consequence is analyzed using fuzzy comprehensive evaluation. Research results show that the severity of accident consequence belong to negligible level, to be considered level, serious level, very serious level and calamitous level are 0.24, 0.28, 0.29, 0.15, 0.04 respectively. The results are useful to prevent ground subsidence accidents caused by the storage caverns. What's more, it also provides according theory and a feasible way for appraising the loss severity before the accident happening.

关键词： Subsidence

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Effect of amount of cetyltrimethylammonium bromide on morphologies of PbS in microwave synthetic systems

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Gongneng Cailiao/Journal of Functional Materials 2011年第SUPPL. 3期42卷 460-463页

作者： Liang, Jian Wei, Zhao-Ling Li, Tian-Bao Zhao, Jun-Fu Li, Jing Xu, Bing-She Key Lab. of Interface Science and Engineering in Advanced Materials of Taiyuan Univ. of Technology Ministry of Education Taiyuan 030024 China College of Materials Science and Engineering Taiyuan University of Technology Taiyuan 030024 China Department of Physics College of Science Taiyuan University of Technology Taiyuan 030024 China

In two microwave synthetic systems, the effect of CTAB on morphologies of PbS materials was studied and preparation of optimal conditions for both star-shaped and flower-like structure were obtained respectively. The results indicated that under the influence of CTAB, the PbS materials with different morphology were obtain. In former system, PbAc2 · 3H2O was used as lead source, thiourea as sulfur source, DMSO as solvent. With decreasing of the amount of CTAB (0, 0.05, 0.1g), a star-like structure with smooth surface, nano-dendritic structure and perfect star-like structure were formed sequentially. For latter system in which Pb(NO3)2 as lead source, L-cysteine as sulfur source, deionized water as solvent, a flower-like structure was obtained when CATB was set up 0.05g;without CATB the sheet structure and partial cube were observed;however, when the addition of CTAB is 0.025g, we can not see absolute flower structure but the result showed a tendency to assemble flower structure. Meanwhile, combining experiments and literatures, the formation mechanisms of PbS with star-shaped and flower-like structure were discussed.

关键词： Morphology

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An integration management system for managing business continuity, records and knowledge

An integration management system for managing business conti...

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International Forum on Information Technology and Applications

作者： An, Xiaomi Chao, Lemen Ye, Liuqi Key Laboratory of Data Engineering and Knowledge Engineering Ministry of Education Renmin University of China Beijing 100872 China Economic Management School Beijing Institute of Petrol-chemical Technology Beijing 102617 China

ISBN: (纸本)9780769541150

Developing an integration management system for business continuity, records and knowledge (IMS of BRK) is beneficial to the collab.ration, optimization and innovation of business continuity management system (BCMS), records management system (RMS) and knowledge management system (KMS) for organization. Comprehensive research and development requirements along with a cogent framework, however, have not been proposed for integrating three of them, which were proposed independently. Based on situational analysis of cross boundaries integration feasibilities in terms of common understandings, general principles and best practice frameworks from relevant national and international standards, this paper proposes integration thinking to combine the advantages of the three paradigms to sustainable competitive advantages;supported by international best practices, the authors propose an integration route covering five levels of integration framework, two integration approaches and three integration controls for dynamic accumulation, sharing and exchange of evidence, memory and knowledge in digital world and global competition. © 2010 IEEE.

关键词： knowledge management

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Full rate and full diversity STBC in decode-and-forward relay systems

Full rate and full diversity STBC in decode-and-forward rela...

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2010 International Conference on Communications and Intelligence Information Security, ICCIIS 2010

作者： Wang, Yong Li, Hui Ministry of Education Key Lab. of Computer Network and Information Security School of Telecommunications Engineering Xidian University Xi'an China

ISBN: (纸本)9780769542607

Diversity techniques are very effective tools to increase signal reception quality in Rayleigh fading channels. A novel space-time block coding method for cooperative relay networks is proposed which guarantees full diversity for any number of mobile relays with minimal delay, provided that few bits of feedback from the destination to the source and the relays are availab.e. As in the case of orthogonal space-time block codes, all transmitted symbols are separately decoded both in the relays and the destination. Therefore, decoding complexity is linear. In our proposed scheme, larger number of codes can be generated for improved coding gain. The performance of the proposed scheme is investigated for cooperative communication. It is shown that the new approach provides SNR improvement, and it is more resilient to feedback errors compared to the antenna selection technique on the basis of same number of feedback bits. © 2010 IEEE.

关键词： Cooperative communication

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Image matching for weld seam tracking based on nonlinear dimensionality reduction method isomap

Image matching for weld seam tracking based on nonlinear dim...

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2010 7th International Conference on Fuzzy Systems and knowledge Discovery, FSKD 2010

作者： Zou, Yirong Du, Dong Guo, Guilin Key Lab. for Advanced Materials Processing Technology Ministry of Education Department of Mechanical Engineering Tsinghua University Beijing China

ISBN: (纸本)9781424459346

An approach of image matching for weld seam recognition is proposed based on the nonlinear dimensionality reduction algorithm Isomap. The target image to be recognized and the template images are considered as high dimensional data. The reduction to 2-D coordinate helps to estimate the relative location of the images. A method of image matching is developed, based on the method of Isomap. ©2010 IEEE.

关键词： Clustering algorithms

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Characteristics of brittle failure and stress drop under triaxial loading and unloading

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Tumu Jianzhu yu Huanjing Gongcheng/Journal of Civil, Architectural and Environmental engineering 2011年第2期33卷 1-6页

作者： Huang, Da Huang, Run-Qiu Zhang, Yong-Xing College of Civil Engineering Chongqing University Chongqing 400045 China Key Lab. For Construction and New Technique of Upland City Ministry of Education Chongqing University Chongqing 400045 China State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of Technology Chengdu 610059 China

The characteristics of deformation failure and stress brittle drop of granite under loading and unloading conditions are studied respectively based on two unloading stress path cases and conventional triaxial compression experiments. The experiments show that the primary deformation of rock is rebound or tension in the (main) unloading direction, but plastic deformation in the non- or sub-unloading direction is not significant. And the curves of stress-strain after peak strength present obvious brittle. Whilst the primary deformation of rock under loading is axial pressure deformation, and plastic deformation increases with the raise of confining pressure. The fracture is characterized by strong tensile, and all tensile cracks are fully developed. Furthermore, when the rock samples are unloaded in two directions, and even normal to unloading direction, sub-unloading annular tensile cracks are produced. The shear fractures is obvious comparatively when confining pressure becomes higher, and it develops following tensile cracks with more micro-tension cracks formed in two sides along shear plane. But the fracture is characterized by shear under conventional triaxial compression with little tensile cracks;the coefficients of brittles stress drop of granite is increased with the growth of confining pressure under conventional triaxial compression and reduced under unloading. When the initial confining pressure is the same, the coefficients of brittles stress drop under unloading is less than that under loading. In Scheme II. the coefficients of brittles stress drop reaches negative when initial confining pressure is up to 30 MPa, and the one (R) is RIII>RI>RII in three test cases.

关键词： Granite

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Research on gas distribution pattern in deep coal-bed based on in-situ detection

Research on gas distribution pattern in deep coal-bed based ...

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International Conference on Digital Manufacturing and Automation (ICDMA)

作者： Xu, Jiang Peng, Shoujian Zhang, Dandan Yang, Hongwei Key Lab. for Exploitation of Southwestern Resources and Environmental Disaster Control Engineering Ministry of Education Chongqing University Chongqing 400044 China

ISBN: (纸本)9780769542867

Knowing about the distribution of gas pressure in coal seam is significative to study the flow of coal seam gas, the occurrence and the change of dynamic phenomenon. An in-situ detection is used to detect the in-situ occurrence of gas in No.3 coal seam in Sihe coal mine of Jincheng Anthracite Mining Group in Shanxi province. The distribution of gas pressure around the holes and the change of the content of gas are studied abstractly, which based on the mathematical simulation of the seam gas-seepage. The results show that insitu detection technique of coal seam gas could shorten the time of from founding the coal to starting to detect, which observably improved the accuracy of testing data, and meanwhile, made up for the deficiency of traditional detection technique in the loss of pressure at earlier stage. It is concluded that the pressure of the initial reservoir gas was about 0.3MPa, from the results of the detection of No.3 coal seam in Sihe coal mine. In order to simulate the distribution of gas pressure surrounding the drilling hole in No.3 coal seam in Sihe coal mine, the mathematical models of the seam gas-seepage were built through COMSOL numerical simulation software. From the results of simulation, the dates on the distribution of gas pressure and the content of gas were obtained. © 2010 IEEE.

关键词： Coal mines

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