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MICROSTRUCTURES AND OXIDATION RESISTANCE OF Fe_3Al WELD OVERLAY

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Acta Metallurgica Sinica(English Letters) 2001年第4期14卷 253-256页

作者： X.G. Mi X.Q. Yu, Y.S. Sun and J.R. Sun department of Materials science and {2. southeast university, nanjing 210096, china Dept. of Mat. Sci. Southeast Univ. Nanjing 210096 China

Using the Fe3Al electrode through manual arc surfacing (MAS), Fe3Al coatings were deposited on the stainless steel substrate. The microstructures, hardness and oxidation resistance of the weld overlay were investigated. The results show that crack-free overlays can be obtained when pre-heating the substrate at 500°C and postweld heat treatment at 700°C are used. Elements of Al, Cr and Ni, etc. transfer between the substrate and the overlay, but this does not influence the microhardness of the substrate and the Fe3Al overlay. Oxidation tests show that the Fe3Al overlay has excellent oxidation resistance in comparison with the stainless steel substrate at 800°C and 900°C.

关键词： Aluminum Intermetallics Iron Microstructure Oxidation resistance

Multidimensional Data Querying on Tree-Structured Overlay

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Wuhan university Journal of Natural sciences 2006年第5期11卷 1367-1372页

作者： XU Lizhen WANG Shiyuan School of computer science and {2. SoutheastUniversity Nanjing 210096 Jiangsu China

Multidimensional data query has been gaining much interest in database research communities in recent years, yet many of the existing studies focus mainly on ten tralized systems. A solution to querying in Peer-to-Peer（P2.） environment was proposed to achieve both low processing cost in terms of the number of peers accessed and search messages and balanced query loads among peers. The system is based on a balanced tree structured P2. network. By partitioning the query space intelligently, the amount of query forwarding is effectively controlled, and the number of peers involved and search messages are also limited. Dynamic load balancing can be achieved during space partitioning and query resolving. Extensive experiments confirm the effectiveness and scalability of our algorithms on P2. networks.

关键词： range query skyline query P2. indexing multi-dimensional data partition

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science china Chemistry 2004年第6期47卷 466-479页

作者： SONG Huajie1,2. XIAO Heming1 & DONG Haishan2.1. department of Chemistry, nanjing {2. of science and Technology, nanjing 2.0094, china 2. Institute of Chemical Materials, china Academy of engineering.Physics, Mianyang 62.900, china 1. department of Chemistry Nanjing University of Science and Technology 210094 Nanjing China 2. Institute of Chemical Materials China Academy of Engineering Physics 621900 Mianyang China

The symmetry-adapted perturbation theory (SAPT) that has the ability in decompo- sition of the total interaction energy into physically meaningful components is used to provide a more fundamental understanding of intermolecular forces. This work was motivated by the diffi- culty of standard SAPT in computing the intermolecular interactions for large energetic dimer systems. SAPT based on Kohn-Sham orbitals (SAPT(DFT)) proves computationally efficient for these large systems, but has been shown to perform poorly for interaction energy components. The deficiencies of SAPT(DFT) result from wrong asymptotical behaviors of commonly used exchange-correlation potentials. To remove the deficiencies, two asymptotic corrections by means of van Leeuwen and Baerends (LB) model potential and Fermi-Amaldi (FA) type potential were applied into three small test systems comprising He2. HF2.and (N2.2.and a set of larger ni- tramide dimers at several separations. The results showed that when utilizing newly developed frequency-dependent density susceptibilities (FDDS) technique for computing dispersion energy, the FA asymptotic correction is very effective to circumvent these deficiencies in SAPT(DFT) and yields a good accuracy over the LB correction. The FA corrected SAPT(DFT) approach is capa- ble of correctly predicting all the quantitative trends in binding energies for all test cases and substantially reduces computational cost as compared with the standard SAPT calculations. The successful application of the approach to nitramide dimer demonstrates that it potentially pro- vides a good means to calculate accurately intermolecular forces in larger system such as en- ergetic systems.

关键词： intermolecular interaction, density functional theory (DFT), symmetry adapted perturbation theory (SAPT), asymptotic correction, frequency-dependent density susceptibilities (FDDS).

ON THE FILTRATION OF NON-NEWTONIAN FLUID IN POROUS MEDIA WITH A MULTIPLE PARAMETER MODEL

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Journal of Hydrodynamics 2001年第1期13卷 39-46页

作者： Zhu Zuo-jin department of Thermal science and Energy {2. university of science and Technology of china, Hefei 2.002., china[WT5”HZ] department of Thermal science and Energy {2. university of science and Technology of china

A multiple parameter model to describe the Non-Newtonian properties of fluid filtration in porous media is presented with regard to the pressure gradient expression in terms of the velocity of filtration, where the multiple parameters should be determined by measurements. Based on such a model, an analysis was furnished to deduce the formula for the rate of production of an oil well, and the governing equations for single phase Non-Newtonian fluid filtration. In order to examine the effects of model parameters, the governing equations were numerically solved with the method of cross-diagonal decomposition ZG method. It is found that, for constant rate of production, the power index n of the model influences the pressure distribution considerably, particularly in the vicinity of a single well. The well-bore pressure of Leibenzonian fluid is lower than that of the power-law fluid in the case of the same parameter B and the power index n=0.5.

关键词： computer simulation Mathematical models Non Newtonian liquids Oil well production

Tribological Properties of Dimpled Surface Alloying Layer on Carbon Steel

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Journal of Wuhan university of Technology(Materials science) 2009年第2期24卷 218-222页

作者：万轶 department of Materials science & {2. Nanjing University of Science and Technology department of Mechanical and Electrical engineering Yingtian College

The effect of surface structure and coating on tribological properties of 45^# carbon steel disc was analyzed. A Nd：YAG laser was used to generate rnicrodirnples on steel surfaces. Dimples with diameter of 150 rn and depth of 50 rn were distributed in an orbicular array on disc surface. Then the alloying element Mo was sputtered to 45# carbon steel disc surface by means of double glow plasma technology. Diffusion Mo alloying layer with 30min thickness and high hardness up to 0.02. was formed on the disc surface. Tribological experiments of three types samples （smooth, texturing and texturing＋alloying） were conducted with a pin-on-disc tribometer. It is found that the dimpled-samples are most effective for reducing friction in comparison with smooth steel surthces, improving the lubricating state from boundary to hydrodynamic region.

关键词： laser surface texturing double glow plasma surface alloying technology carbon steel tribological performance lubricating state

An unconstrained optimization method using nonmonotone second order Goldstein's line search

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science china Mathematics 2007年第10期50卷 1389-1400页

作者： Wen-yu SUN~(1+) Qun-yan ZHOU~(1,2. ~1 School of Mathematics and computer science,{2. Normal university,{2. 2.0097,china ~2.department of Basic Courses,jiangsu.Teachers university of Technology,Changzhou 2.3001,china 1. School of Mathematics and computer science Nanjing Normal University Nanjing 210097 China 2. department of Basic Courses Jiangsu Teachers University of Technology Changzhou 213001 China

In this paper, an unconstrained optimization method using the nonmonotone second order Goldstein's line search is proposed. By using the negative curvature information from the Hessian,the sequence generated is shown to converge to a stationary point with the second order optimality conditions. Numerical tests on a set of standard test problems confirm the efficiency of our new method.

关键词： nonmonotone method, direction of negative curvature, line search, descent pair,unconstrained optimization

Technical framework for Internetware: An architecture centric approach

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science in china(Series F) 2008年第6期51卷 610-622页

作者： YANG FuQing1,2. Lü Jian3,4 & MEI Hong1,2.1 Key Laboratory of High Confidence Software Technologies (Peking university), Ministry of Education, Beijing 100871, china 2.School of Electronics {2.and computer science, Peking university, Beijing 100871, china 3 State Key Laboratory for Novel Software Technology, nanjing 2.0093, china 4 department of computer science and Technology, nanjing university, nanjing 2.0093, china 1. Key Laboratory of High Confidence Software Technologies (Peking university) Ministry of Education Beijing 100871 China 2. School of Electronics engineering.and computer {2. Peking University Beijing 100871 China 3. State Key Laboratory for Novel Software Technology Nanjing 210093 China 4. department of computer {2. and Technology Nanjing University Nanjing 210093 China

Being a new software paradigm evolved by the Internet, Internetware brings many challenges to the traditional software methods and techniques. Sponsored by the national basic research program （973）, researchers in china have developed an architecture centric technical framework for the definition, incarnation and engineering.of Internetware. First of all, a software model for Internetware is defined for what to be, including that Internetware entities should be packaged as components, behaving as agents, interoperating as services, collaborating in a structured and on demand manner, etc. Secondly, a middleware for Internetware is designed and implemented for how to be, including that Internetware entities are incarnated by runtime containers, structured collaborations are enabled by runtime software architecture, Internetware can be managed in a reflective and autonomic manner, etc. Thirdly, an engineering.methodology for Internetware is proposed for how to do, including the way to develop Internetware entities and their collaborations by transforming and refining a set of software architectures which cover all the phases of software lifecycle, the way to identify and organize the disordered software assets by domain modeling, etc.

关键词： Internetware component software architecture agent middleware

Deterministic secure quantum communication without unitary operation based on high-dimensional entanglement swapping

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science china(Information sciences) 2012年第2期55卷 360-367页

作者： LIU ZhiHao1,CHEN HanWu1,LIU WenJie2.XU Juan1 & LI ZhiQiang3 1School of computer science and {2.southeast university,nanjing 2.1189,china 2.chool of computer and Software,nanjing university of Information science & Technology,nanjing 2.0044,china 3College of Information {2.Yangzhou university,Yangzhou 2.5009,china 1. School of computer science and {2. Southeast University Nanjing 211189 China2. School of Computer and Software Nanjing University of Information Science & Technology Nanjing 210044 China3. College of Information Engineering Yangzhou University Yangzhou 225009 China

By analysis of the basic properties of entanglement swapping of high-dimensional Bell states,a universal and general deterministic secure quantum communication(DSQC)protocol is proposed,in which unitary operation is not *** making use of the results of high-dimensional Bell measurement,the sender and the receiver can encode and decode the message respectively by performing the modular addition and *** mutually complementary bases are constructed;and according to the property of mutual complement,a method for checking security of the high-dimensional quantum channel is put *** common attack strategies are analyzed,and the corresponding error rates are *** the upper bound of the threshold of error rate is deduced.

关键词： deterministic secure quantum communication high-dimensional Bell state entanglement swap-ping high-dimensional Bell measurement

Scheduling in a Meta Search Engine by Genetic Algorithm

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Wuhan university Journal of Natural sciences 2001年第Z1期6卷 541-546页

作者： Zhang Wei feng, Xu Bao wen, Zhou Xiao yu, Huang Hui department of computer {2. and engineering. southeast university, nanjing 210096,china State Key Laboratory of Software engineering. Wuhan university, Wuhan 430072.china department of computer {2. and engineering Southeast University Nanjing 210096 China

The meta search engines provide service to the users by dispensing the users' requests to the existing search engines. The existing search engines selected by meta search engine determine the searching quality. Because the performance of the existing search engines and the users' requests are changed dynamically, it is not favorable for the fixed search engines to optimize the holistic performance of the meta search engine. This paper applies the genetic algorithm (GA) to realize the scheduling strategy of agent manager in our meta search engine, GSE(general search engine), which can simulate the evolution process of living things more lively and more efficiently. By using GA, the combination of search engines can be optimized and hence the holistic performance of GSE can be improved dramatically.

关键词： WWW internet search engine meta search engine genetic algorithm agent