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The 1st International Congress on Advanced Materials 2011

作者： HongQuan Liu Gang Zhou FeiXiang Hao YiJie Gu XinBing Zhao college of Materials Science and Engineering Shandong University of Science and Technology Key Laboratory of Mine Disaster Prevent ion and Control Shandong University of Science and Technology Department of Materials Science State Key Laboratory of Silicon MaterialsZhejiang University

The xPbTe/Yb 0.2 Co 4 Sb 12 compounds were prepared by the ball-milling and hot-pressed process. Electrical conductivity of the composite samples reduces with decrease of PbTe content, and their temperature dependence coefficients show positive values. The maximum of electrical conductivity of composite materials is about 80000 Sm -1 at 800K. Seebeck coefficient (absolute value) of composite materials is obviously improved with increase of dispersed phase(PbTe) content, and Seebeck coefficient(absolute value) of the 10PbTe sample reaches about -260 VK -1 at 700K, which increase by 13.6% in comparison with that of Yb 0.2 Co 4 Sb 12 sample. Thermal conductivities of composite samples are improved due to induction of PbTe, and thermal conductivity of 10PbTe sample reaches about 3 Wm - 1 K -1 at 550K. The maxnium value of ZT reached 0.78 at 700K for 2.5PbTe.

关键词： thermoelectric materials Composite material thermoelectric properties thermal conductivity

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Study and Prevention on the Diffusion Rule of Dust Pollution in the Coal Mine Whole-Rock Fully Mechanized Workface

Study and Prevention on the Diffusion Rule of Dust Pollution...

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The 2nd International Conference on Computer-Aided Design, Manufacturing, Modeling and Simulation(CDMMS 2012)

作者： Cheng Weimin Nie Wen Pan Gang Cao Sen Zhang Xinhua College of Resource and Environmental Engineering Shandong University of Science and Technology Qingdao Key Laboratory of Mining Disaster Prevention and Control Ministry of Education Shandong University of Science and Technology Qingdao

ISBN: (纸本)9783037855409

The mathematical model of solving two-phase flow of gas and dust particles was built by established the k-ε-Θ-kp ***,by using FLUENT software,the diffusion rule of dust pollution in the whole-rock fully mechanized workface was researched with different air-draft *** result showed that when the air-draft amount increased from 320m3/min to 600m3/min,de-dust ability of extraction fan drum is gathering strength,pervasion intensity of producing dust is continuously decreased in tunneling *** simulation results of each measuring point are basically consistent with the field measurement results.

关键词： K-Ε-Θ-Kp Equation,Air-Draft Amount,Dust Pollution,Coal Mine

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Field Test Research on Two-dimensional Gas Concentration and Temperature Distribution in the Goaf of Fully Mechanized Caving Face

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Procedia engineering 2012年 43卷 478-483页

作者： Gang Wang Weimin Cheng Jun Xie State Key Laboratory of Ministry of Mining Disaster Prevention and Control Shandong University of Science and Technology Qingdao 266590 China CSIRO Earth Science and Resource Engineering P.O. Box 883 Kenmore QLD 4069 Australia

The gas, oxygen, carbon monoxide and acetylene concentration and the temperature distribution of longwall goaf areas were analyzed by means of burying pipes and temperature sensor. Furthermore, the regulation of “three zones” distribution of 1361 face in Jinyuan colliery by the oxygen concentration and the temperature distribution has been worked out, and the limited velocity of the working face has been marked off. The research results showed that the gas concentration was low intake airflow roadway along goaf towards direction. The goaf gas concentration in return airway was far higher than intake airflow roadway. There was not combustion phenomenon during the test in the 1361 goaf of the coal mining. Meanwhile, the results also confirmed mining extraction process source of gas accumulation in face corner, also can be used for providing the basis of enacting fire prevention measures in the goaf and gas management measures for face corner.

关键词： Fully mechanized caving face Two-dimensional Goaf Test study

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A SCHEME OF DATA CONFIDENTIALITY AND FAULT-TOLERANCE IN CLOUD STORAGE

A SCHEME OF DATA CONFIDENTIALITY AND FAULT-TOLERANCE IN CLOU...

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2012 IEEE 2nd International Conference on Cloud Computing and Intelligence Systems

作者： Yongkang Fu Bin Sun Information Security Center State Key Laboratory of NetWorking and Switching TechnologyBeijing University of Posts and Telecommunications National Engineering Laboratory for Disaster Backup and Recovery Beijing University of Posts and Telecommunications State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University

The off-premises storage paradigm that comes with cloud storage has incurred great concerns on the security of data, especially the integrity and confidentiality of data. The untrusted cloud providers' complete control over data may endanger data confidentiality, at the same time the invaders or accident of storage device may also damage the availability of data. Our research is mainly concentrated on the confidentiality of data, the recovery of loss data and the repair of error data. We provide a security scheme for the data stored in a remote cloud storage system, and the scheme is based on symmetric encryption technology and erasure codes. Boot password is adopted to avoid the problem of key preservation and management which is used in traditional symmetric encryption technology and tornado code is introduced as the basis for the redundant system to overcome the lost data recovery issues. To the end, keyed-Hash which adds additional error correction function to the tornado code is brought forth to solve the problem of tampering of data. The simulation results show that the scheme is efficient in recovering loss data and provide good resistance to the Byzantine faults, meanwhile it has high computing efficiency, especially when processing a big file.

关键词： Cloud Storage Data security Data redunda ncy Byzantine faults Tornado code

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Investigation of convection control under the non-uniform RMF in a liquid bridge

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Procedia engineering 2012年 31卷 659-664页

作者： Liping Yao Zhong Zeng Jingqiu Chen Liang Li Hiroshi Mizuseki Yoshiyuki Kawazoe Department of Engineering Mechanics Chongqing University Chongqing 400044 PR China State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing University Chongqing 400044 PR China Institute forMaterialsResearch TohokuUniversity Sendai 980-8577Japan

Under microgravity, thermocapillary flow becomes the dominant convection in float-zone crystal growth, it may lose stability with increasing Marangoni number, and the convection instability is detrimental to crystal quality. Because of the excellent electrical conductivity of semiconductor melt, the external rotating magnetic field (RMF) is applicable to control melt convection. In a typical simplified float-zone model, the influences of the non-uniform RMF, which is generated by the RMF inductor with three pairs of poles, on the three-dimensional thermocapillary flow are investigated numerically. Our results demonstrate that the axial velocities are reduced under the non-uniform RMF while the melt is stirred in azimuthal direction by RMF, as a result, the three-dimensional convection after the instability becomes to a two-dimensional axisymmetrical flow. It implies that the non-uniform RMF can control melt convection effectively for high-quality crystal growth.

关键词： Rotating magnetic fields thermocapillary convection floating zone Marangoni convection microgravity

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Simulation Analysis Study on the Flow Field of the Collar in Sucker Rod

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Procedia engineering 2012年 29卷 4273-4277页

作者： Jing-cheng Liu Hong-tu Wang Jun-lian He Shun-peng Zeng College of Petroleum Engineering Chongqing University of Science and Technology Chongqing 401331China Chongqing Petroleum and Natural gas Society Chongqing400030China Key Laboratory for Exploitation of Southwestern Resources & Environmental Disaster Control Engineering Ministry of EducationChongqing University Chongqing 400030 China

During oil well production, it was a serious phenomenon of wax deposition on the parts such as oil production system section *** the fluid flow problem of the collar in sucker rod, the research of this thesis applies Flunt software to perform numerical simulation of the flow conditions under different outputs, and presents relevant velocity vector and velocity nephogram of the crude oil at the collar in sucker rod. Through analysis, it was believed that the wax deposition could not be efficiently settled only by high fluid velocity raised by output increase, and the relevant technical measures were proposed to prevent wax deposition, providing the theoretical thesis for paraffin removal and control at oil well.

关键词： wax deposition,the collar,sucker rod,numerical simulation paraffin removal and control

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BGP path verification mechanism based on sanitizable signature

International Journal of Digital Content Technology and its ...

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International Journal of Digital Content Technology and its Applications 2012年第21期6卷 274-282页

作者： Zhao, Chen Sun, Bin Yang, Yixian Yang, Yan Information Security Center Beijing University of Posts and Telecommunications Beijing 100876 China State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University Beijing 100044 China National Engineering Laboratory for Disaster Backup and Recovery Beijing University of Posts and Telecommunications Beijing 100876 China

The Border Gateway Protocol (BGP) is the de facto routing protocol for inter-domain routing in Internet. For security hidden danger, the path information (AS_PATH attribute) is highly vulnerable to a variety of malicious attacks. Although many security solutions for path verification have been proposed, none has been widely deployed because of excessive route resource consumption. The sanitizable signature is introduced into path verification combined with the character of AS_PATH attribute. A novel security mechanism is designed for BGP path verification named SSPV (Sanitizable Signature Based Path Verification) through overcoming the application defects of sanitizable signature. Security and performance analysis show that SSPV can eliminate the cumulated signature of route messages. It reduces the number of signatures and used certificates to provide protection for path information compared with traditional solutions.

关键词： Border Gateway Protocol

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LQG PREDICTED control BASED ON RBF NEURAL NETWORK

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The Twelfth International Symposium on Structural engineering

作者： Yanhui Liu Ping Tan Fulin Zhou Yongfeng Du Weiming Yan State Key Laboratory for Seismic Reduction /Control & Structural Safety(Cultivation) Guangzhou University Beijing key Lab of Earthquake Engineering and Structural Retrofit Beijing University of Technology Institute of Earthquake Protection and Disaster Mitigation Lanzhou Univ.of Tech.

ISBN: (纸本)9787030357878

In order to solve the effect of time lag in the process of structural vibration control,Linear Quadratic Guassian Predicted controller(LQGPC) is deduced based on *** controller can forcaste the control force at next serveral steps according to to-be moment response of controlled *** the signal of control force at next serveral steps was set to control system accroding to time lag of control ***,A five -story smart isolated frame structure is analyzed by adopting the LQGPC in the case of different time *** results show that control effects of LQG and LQGPC have the favorable control efficiency and both two algorithms can decrease the response of the structure effectively in the case of no time lag,but LQGPC still has better ability of controlling structural response in the case of different time lag existing in system.

关键词： Vibration control time lag based isolation LQG controller RBFNN

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Research on diffusion rule of dust pollution in coal mine whole-rock fully mechanized workface

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Journal of Convergence Information Technology 2012年第22期7卷 728-736页

作者： Cheng, Weimin Nie, Wen Qi, Yudong Yao, Yujing College of Resource and Environmental Engineering Shandong University of Science and Technology Qingdao China Key Laboratory of Mining Disaster Prevention and Control Ministry of Education Shandong University of Science and Technology Qingdao China Sany Heavy Industry Co. Ltd Changsha China

According to the problem that the diffusion rule of dust pollution in the coal mine whole-rock fully mechanized workface cannot be obtained by doing model experiment and field measurement, the mathematical model of solving two-phase flow of gas and dust particles was built by established the k- Ε-Θ-kp equation. Moreover, by basing on collocated grid SIMPLE algorithm and using FLUENT software, the diffusion rule of dust pollution in the whole-rock fully mechanized workface was explored with different air-draft amount. The result showed that when the air-draft amount increased from 320m3/min to 600m3/min, de-dust ability of extraction fan drum is gathering strength, pervasion intensity of producing dust is continuously decreased in tunneling place, the mean dust concentration of driver's location and whole section was decreased 51.28% and 56.51% respectively, and diffusion distance of high dust concentration has reduced from 13.6m to 8.5m. After the air-draft amount increased from 320m3/min to about 600m3/min, the simulation results of each measuring point are basically consistent with the field measurement results. It suggests that increasing the air-draft amount to 600m3/min was the effective way to prevent dust pollution of tunneling place from diffusing to other roadway areas.

关键词： Coal mines

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Out-of-plane Compression and Impact of Woven Textile Sandwich Composites

Out-of-plane Compression and Impact of Woven Textile Sandwic...

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International Conference on Digital Manufacturing & Automation

作者： Long ZHAO Hualin FAN Shiqing HUANG People's Liberation Army University of Science and Technology Nanjing China Laboratory of Structural Analysis for Defense Engineering and Equipment College of Mechanics and Materials Hohai University HHU Nanjing China State Key Laboratory of Automotive Safety and Energy Tsinghua University Beijing China MOE Key Laboratory of Disaster Forecast and Control in Engineering Jinan University Guangzhou China

Woven textile sandwich composite (WTSC) is a light-weight structural material. The manufacturing method of WTSC was introduced in the paper. To reveal the quasi-static and the dynamic crushing behavior of WTSC, out-of-plane compression tests were carried out. Low-velocity impact experiments were carried out to investigate the anti-crush ability of WTSC. The results of the quasi-static and dynamic compression tests show that the woven textile sandwich material has good energy absorption ability. From the difference of the peak loads, it is concluded that the woven textiles have strain rate sensitivity. The intact woven textile sandwich panel and the destroyed one have different anti-crush abilities. Different methods are used to enhance the anti-penetrating of the intact woven textile sandwich panels, for example, increasing the content of the glass fibers, enlarging the diameter of the glass fibers and enlarging the height of front faces and the whole panel. From the experiments, it is concluded that WTSC has light weight, great specific strength and good energy absorption ability. WTSC is a promising light-weight structural material for vehicle bodies.

关键词： Woven textile sandwich composite Out-of-plane compression Low-velocity impact

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