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Concurrent collision probability of RFID tags in underground mine personnel position systems

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Mining Science and Technology 2010年第5期20卷 734-737页

作者： JI Yuchu,XU Zhao,FENG Qinzhu,SANG Yuan School of Information & Electrical Engineering,china university of Mining & Technology,Xuzhou 221008,china [a] School of Information&Electrical Engineering China University of Mining&Technology Xuzhou 221008 China

According to the basic requirements of underground mine personnel position systems and the working characteristics of active RFID tags,we studied the cause of concurrent collision of RFID tags and leak reading probability,by means of theoretical analysis and *** result shows that the probability of wireless collision increases linearly with an increase in the number of *** probability of collision and leak reading can be reduced by extending the working period of the duty cycle and using a backoff *** a practical application,a working schedule for available labels has been designed according to the requirement of the project.

关键词： personnel position system RFID collision probability of RFID tag

Laboratory Investigation of Zinc Recovery fromEAF Dust by Bath Smelting Reduction

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International Journal of Minerals,Metallurgy and Materials 2000年第1期14卷 18-23页

作者： Weiqing Chen Tarek El Gammal Metallurgy School, university of Science & Technology Beijing, Beijing 100083, china Institute for Ferrous Metallurgy, Aachen university of Technology, Germany Univ Sci & Technol Beijing Met Sch Beijing 100083 Peoples R China Aachen Univ Technol Inst Ferrous Met Aachen Germany

Bath smelting reduction for recovering zinc from EAF (Electric Arc Furnace) dust has been investigated in the laboratory. A degree of zinc volatilization of more than 99% was obtained from the process. Temperature has a clear influence on the reduction rate of ZnO in slag. The reduction rate of (ZnO) by [C] is the first order with respect to the content of ZnO in the slag. The apparent activation energy of the (ZnO) reduction reaction is 312 kJ/mol at 1300-1500℃.

关键词： EAF dust ZnO smelting reduction reduction rate

AutoProc: An automatic proactive replication scheme for P2P storage

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Science china(Information Sciences) 2011年第6期54卷 1151-1160页

作者： YANG Zhi & DAI YaFei Computer Science Department, Peking university, Beijing 100871, china 1. Computer Science Department Peking University Beijing 100871 China

Due to the prevalence of peer departures, P2P storage systems need to constantly generate replicas for high durability. However, few existing systems are able to select the right replication rate that balances replication cost and durability, e.g., minimizing replication cost without threatening the durability target. In this paper, we propose a method called AutoProc to automate the replication process in P2P storage systems. AutoProc employs two key techniques to enable cost-effective replication: correctly adapting replication rate with a reliability model, and replicating objects at the right order with a reliability indicator. Extensive simulations based on the real system failure trace show that AutoProc achieves the near-optimal performance.

关键词： P2P storage churn durability fault tolerance proactive replication resource usage

EFFECT OF DISCHARGE RATIO ON FLOW CHARACTERISTICS IN 90°EQUAL-WIDTH OPEN-CHANNEL JUNCTION

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Journal of Hydrodynamics 2009年第4期21卷 541-549页

作者： ZHANG Ting XU Wei-lin WU Chao College of Civil Engineering Fuzhou University Fuzhou 350108 China State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University Chengdu 610065 China

For the 90° equal-width open-channel junction flow, the Reynolds averaged Navier-Stokes equations are solved while using the 3-D κ- ω model. The mean flow pattern and the secondary current are obtained. The model is validated by experimental data, and then applied to investigate the effect of the discharge ratio on the shape of separation zone shape, the cross-sectional mean flow angle and the contraction coefficient. The results are fairly close to those of the prior studies. The numerical modeling is both less time-consuming and less expensive to obtain the various flow parameters needed for engineering design.

关键词： κ- ω turbulent model open-channel junction separation zone secondary current

A method for solving Nash equilibria of games based on public announcement logic

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Science china(Information Sciences) 2010年第7期53卷 1358-1368页

作者： CUI JianYing & TANG XiaoJia Institute of Logic and Intelligence, Southwest university, Chongqing 4.0715, china 1. Institute of Logic and Intelligence Southwest University Chongqing 400715 China

Describing the interactional behavior of rational agents and seeking equilibria are two main domains of game theory. The epistemic foundation of the above two domains is based on the assumption that all players are rational. However, game theory itself cannot precisely model the higher-order information changes of mutual knowledge among players, so in the current studies of game theory the interpretations of rationality are vague. In this paper, a concept of the rationality is redefined through incorporating an epistemic ingredient. Then a method is proposed to solve and refine Nash equilibria which is grounded on public announcement logic, and it is proved that the iterated announcement of this rationality assertion characterizes the iterated admissibility algorithm in game theory, which offers a dynamic epistemic foundation for this algorithm. Finally, an implementation of this method, based on the extended DEMO, is shown to be correct.

关键词： iterated admissibility algorithm rationality public announce logic demo

Geochemistry of Permian Coal and Its Combustion Residues in Huainan Coalfield, china

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Journal of china university of geosciences 2001年第4期12卷 283-290页

作者： Huang Wenhui Yang Qi Department of Energy Resources and Geology , china university of geosciences , Beijing 100083 Peng Suping Department of Geology and Engineering, china university of Mining and Technology, Beijing 100083 Zhao Zhigen Department of R Department of Energy Resources and Geology China University of Geosciences Beijing 100083 Department of Geology and Engineering China University of Mining and Technology Beijing 100083 Department of Resources and Environment Huainan Institute of Technology Huainan 232001

INAA (instrumental neutron activation analysis) was used to determine the contents of trace elements in coal samples from 11 workable Permian coal seams in Huainan coalfield. With XRFS (X-ray fluorescence spectrometry), the geochemical composition of its combustion residues from Tianjiaan Power Plant and Luohe Power Plant was analyzed. In addition, the electron microprobe was employed to study the chemical composition of some fly ashes and bottom ashes. Compared with those of the coals around the world, most trace elements of the Huainan coal are characterized by a normal abundance. Like most coals worldwide, the elements Se, S, As, Sb, Br, U and Cl are enriched in Huainan coal according to dark's value, while the other elements tend to be diluted. The large fluctuation in the contents of trace elements in this kind of coal demonstrates great differences in coal seams. On the other hand, the contents of these elements are very similar in different bottom and fly ash samples. The elements with low organic affinity tend to concentrate in fly and bottom ash than in coal, especially those elements associated with Fe. However, the elements with strong organic affinity tend to be volatile during the combustion. Moreover, the abundance of the elements in fly ash and bottom ash changes with different densities and with different particle sizes. The bottom and fly ashes consist of glass, lime, mullite, coal residues and ferrite minerals. Some residual chars contain higher contents of volatile elements, such as S, P, Cl and As, indicating that the ash containing more residual chars has a strong adsorption of some hazardous elements, suggesting a possible utilization of power plant ash in the field of water cleaning.

关键词： coal trace element combustion residues geochemistry INAA china.

FORMATION AND INFLUENCING FACTORS OF FREE SURFACE VORTEX IN A BARREL WITH A CENTRAL ORIFICE AT BOTTOM

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Journal of Hydrodynamics 2009年第2期21卷 238-244页

作者： LI Hai-feng CHEN Hong-xun MA Zheng ZHOU Yi Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 China china Ship Scientific Research Center Wuxi 214082 China

Based on the Navier-Stokes equations with considering the effect of the Coriolis force, the finite volume method was employed to discretize the governing equations, the SIMPLE method was adopted to solve the discretized equations, and the flow field in a barrel with an outlet at the center of the bottom was simulated. The numerical results agree well with the experimental data. From the Lagrangian, the relations among the acceleration, the Coriolis force and the viscosity force were analyzed. The results show that the Coriolis force is the major factor that causes the formation of the vortex. The flow fields in the flume under different incoming flow conditions were numerically simulated using the software Fluent. The numerical simulations show good agreement with the experiments for the shape and position of the vortex.

关键词： free surface vortex Coriolis force numerical simulation

Lipschitz functions on Banach spaces which are actually on Asplund spaces

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Chinese Science Bulletin 1997年第24期42卷 2051-2054页

作者： CHENG Lixin Shi ShuzhongNankai Institute of Mathematics, Nankai university, Tianjin 300071, china Nankai Institute of Mathematics Nankai University Tianjin China

SINCE Namioka and Phelps, starting with Asplund’s pioneering work, introduced the no-tion of Asplund spaces (those are Banach spaces on which every continuous convex function isFrechet differentiable on a dense G_δ subset) and proved that the dual of an Asplund space hasthe Radon-Nikodym property (RNP), the study of differentiability properties of functions oninfinite dimensional spaces has continued widely and deeply (see, for instance, Phelps andGiles). The research attained a great achievment after Stegall’s theorem: If the dualspace E~* has the RNP, then E is an Asplund space. Because of the N-Ph-S theorem, we

关键词： mathematics Lipschitz function Radon-Nikodym property subdifferential Banach space.

A Remark on the Symplectic Blow-up in Dimension 4

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Acta Mathematica Sinica,English Series 1996年第4期12卷 379-384页

作者： Ma Renyi Department of Applied Mathematics Tsinghua university Beijing, 100084.1} Department of Applied Mathematics Tsinghua University Beijing China

In this note, we prove that the symplectic blow-up or blow-down in the dimension 4.is rigid, i.e. the symplectic area of the divisor does not exceed the symplectic radius of the neighbourhood on which we do the blow-u... 详细信息

关键词： J-Holomorphic disc Contact manifold Symplectic blow-up