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Some Analytical Properties of the Model for Stochastic Evolutionary Games in Finite Populations with Non-uniform Interaction Rate

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Communications in Theoretical Physics 2013年第7期60卷 37-47页

作者： QUAN Ji WANG xian-jia GuangDong Electric Power Design Institute China Energy Engineering Group Co. Ltd Guangzhou 510663 China Department of Management and Economics Tianjin University Tianjin 300072 China Institute of Systems Engineering Wuhan University Wuhan 430072 China School of Economics and Management Wuhan University Wuhan 430072 China

Traditional evolutionary games assume uniform interaction rate, which means that the rate at which individuals meet and interact is independent of their strategies. But in some systems, especially biological systems, the players interact with each other discriminately. Taylor and Nowak (2006) were the first to establish the corresponding non-uniform interaction rate model by allowing the interaction rates to depend on strategies. Their model is based on replicator dynamics which assumes an infinite size population. But in reality, the number of individuals in the population is always finite, and there will be some random interference in the individuals' strategy selection process. Therefore, it is more practical to establish the corresponding stochastic evolutionary model in finite populations. In fact, the analysis of evolutionary games in a finite size population is more difficult. Just as Taylor and Nowak said in the outlook section of their paper, 'The analysis of non-uniform interaction rates should be extended to stochastic game dynamics of finite populations.' In this paper, we are exactly doing this work. We extend Taylor and Nowak's model from infinite to finite case, especially focusing on the influence of non-uniform connection characteristics on the evolutionary stable state of the system. We model the strategy evolutionary process of the population by a continuous ergodic Markov process. Based on the limit distribution of the process, we can give the evolutionary stable state of the system. We make a complete classification of the symmetric 2×2 games. For each case game, the corresponding limit distribution of the Markov-based process is given when noise intensity is small enough. In contrast with most literatures in evolutionary games using the simulation method, all our results obtained are analytical. Especially, in the dominant-case game, coexistence of the two strategies may become evolutionary stable states in our model. This result can be used to

关键词： stochastic evolutionary games non-uniform interaction rate finite population evolutionary stablestate

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Selective interfacial bonding and thermal conductivity of diamond/Cu-alloy composites prepared by HPHT technique

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International Journal of Minerals,Metallurgy and Materials 2012年第4期19卷 364-371页

作者： Hui Chen Cheng-chang jia Shang-jie Li xian jia Xia Yang School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Shenzhen Haimingrun Industrial Co. Ltd. Shenzhen 518126 China

Cu-based and Cu-alloy-based diamond composites were made by high-pressure-high-temperature （HPHT） sintering with the aim of maximizing the thermal conductivity of the composites. Improvements in interfacial bonding strength and thermo-physical properties of the composites were achieved using an atomized copper alloy with minor additions of Co, Cr, 13, and Ti. The thermal conductivity （TC） oh- mined exhibited as high as 688 W.m-1.K-1, but also as low as 325 W.m-1.K-l. A large variation in TC can be rationalized by the discrepancy of diamond-matrix interfacial bonding. It was found from fractography that preferential bonding between diamond and the Cu-alloy matrix occurred only on the diamond {100} faces. EDS analysis and Raman spectra suggested that selective interfacial bonding may be attributed to amorphous carbon increasing the wettability between diamond and the Cu-alloy matrix. Amorphous carbon was found to significantly affect the TC of the composite by interface modification.

关键词： metallic matrix composites diamonds copper alloys interfacial bonding thermal conductivity

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Fabrication,microstructures,and properties of copper matrix composites reinforced by molybdenum-coated carbon nanotubes

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Rare Metals 2011年第4期30卷 401-407页

作者： NIE Junhui jia Chengchang jia xian ZHANG Yafeng SHI Na LI Yi School of Matertals Sctence and Engmeermg Umverszty of Sctence and Technology Beijing Beijing 100083 China China Iron ＆ Steel Research Institute Group Beijing 100081 China

Multiwalled carbon nanotubes （CNTs） were coated by a molybdenum layer using carbonyl thermal decomposition process with a precursor of molybdenum hexacarbonyl. The Mo-coated CNTs （Mo-CNTs） were added into copper powders to fabricate Mo-CNT/Cu composites by means of mechanical milling followed by spark plasma sintering. The Mo-CNTs were uniform dispersion in the Cu matrix when their contents were 2.5 vo1.%-7.5 vol.%, while some Mo-CNT clusters were clearly observed at additions of 10.0 vo1.%-15.0 vol.% Mo-CNTs in the mixture. The mechanical, electrical, and thermal properties of the Mo-CNT/Cu composites were characterized, and the results showed that the tensile strength and hardness were 2.0 and 2.2 times higher than those of CNT-free specimens, respectively. Moreover, the Mo-CNT/Cu composites exhibited an enhanced thermal conductivity but inferior electrical conductivity compared with sintered pure Cu. The uncoated CNT/Cu composites were fabricated by the similar processes, and the measured tensile strength, hardness, thermal conductivity, and electrical conductivity of the CNT/Cu composites were lower than those of the Mo-CNT/Cu composites.

关键词： metallic matrix composites mechanical properties ball milling molybdenum carbon nanotubes

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The evolution of cooperation in public good game with deposit

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Chinese Physics B 2019年第8期28卷 22-30页

作者： xian-jia Wang Wen-Man Chen Economics and Management School Wuhan UniversityWuhan 430070China Institute of System and Engineer Wuhan UniversityWuhan 430070China

The emergence of cooperation still remains a fundamental conundrum in the social and behavior *** introduce a new mechanism,deposit mechanism,into theoretical model to explore how this mechanism promotes cooperation in a well-mixed ***,we extend the common binary-strategy combination of cooperation and defection in public good game by adding a third strategy,namely,deposit *** players with deposit cooperation strategy pay a deposit in advance to obtain the benefits of public good at a lower contributions compared with the players with cooperation strategy,when the provision of public good is ***,we explore the evolution of cooperation in the public good game with deposit by means of the replicator *** computations and stimulations show that the deposit mechanism can promote cooperation in a well-mixed population,and the numbers of equilibrium point are determined by variables of public good *** the one hand,when the coexistence of cooperators and defectors is the stable equilibrium point in the evolutionary system,increasing the threshold of public good and adopting the weak altruism way for share benefits can enhance the level of cooperation in the *** the other hand,if the coexistence of deposit cooperators and defectors is the stable equilibrium point,it is effective to promote the deposit cooperation by lowering the values of discount and deposit,and raising the threshold of public good.

关键词： evolutionary game theory cooperation deposit weak altruism discount rate

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Evolution of donations on scale-free networks during a COVID-19 breakout

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Chinese Physics B 2022年第8期31卷 212-225页

作者： xian-jia Wang Lin-Lin Wang Economics and Management School Wuhan UniversityWuhan 430072China Institute of Systems Engineering Wuhan UniversityWuhan 430072China

Having a large number of timely donations during the early stages of a COVID-19 breakout would normally be considered rare. Donation is a special public goods game with zero yield for donors, and it has the characteristics of the prisoners’ dilemma. This paper discusses why timely donations in the early stages of COVID-19 occurred. Based on the idea that donation is a strategy adopted by players during interconnection on account of their understanding of the environment, donation-related populations are placed on social networks and the inter-correlation structures in the population are described by scale-free networks. Players in donation-related populations are of four types: donors, illegal beneficiaries,legal beneficiaries, and inactive people. We model the evolutionary game of donation on a scale-free network. Donors,illegal beneficiaries and inactive people learn and update strategies under the Fermi update rule, whereas the conversion between legal beneficiaries and the other three types is determined by the environment surrounding the players. We study the evolution of cooperative action when the agglomeration coefficient, the parameters of the utility function, the noise intensity, the utility coefficient, the donation coefficient and the initial states of the population on the scale-free network change. For population sizes of 50, 100, 150, and 200, we give the utility functions and the agglomeration coefficients for promoting cooperation and study the corresponding steady states and structural characteristics of the population. We identify the best ranges of the noise intensity K, the donation coefficient α and the utility coefficient β for promoting cooperation at different population sizes. Furthermore, with the increase of the population size, the donor traps are *** the same time, it is discovered that the initial states of the population have a great impact on the steady states;thus the upper and lower triangle phenomena are proposed. We also fi

关键词： donation public goods game evolutionary game scale-free network

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Thermal conductivity behavior of SPS consolidated AlN/Al composites for thermal management applications

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Rare Metals 2011年第2期30卷 189-194页

作者： DUN Bo jia xian jia Chengchang CHU Ke School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China General Research Institute for Nonferrous Metals Beijing 100088 China

A1N/A1 composites are a potentially new kind of thermal management material for electronic packaging and heat sink applications. The spark plasma sintering （SPS） technique was used for the first time to prepare the A1N/A1 composites, and attention was focused on the effects of sintefing parameters on the relative density, microstructure and, in particular, thermal conductivity behavior of the composites. The results showed that the relative density and thermal conductivity of the composites increased with increasing sintering temperature and pressure. The composites sintered at 1550℃ for 5 min under 70 MPa showed the maximum relative density and thermal conductivity, corresponding to 99% and 97.5 W.m-1.K-1, respectively. However, the thermal conductivity of present A1N/A1 composites is still far below the theoretical value. Possible reasons for this deviation were discussed.

关键词： metallic matrix composites aluminum nitride spark plasma sintering density thermal conductivity

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Comparative Studies on Mass Spectrometric Fragmentation of Linear Chiral Secondary Alcohols (R)-1-(4-Alkylphenyl) and (R)-1-(4-Alkoxyphenyl/Alkylthiophenyl) Alcohols

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Chemical Research in Chinese Universities 2006年第3期22卷 347-350页

作者： ZHANG Qi-han SU xian-bin XU jia-xi Key Laboratory of Bioorganic Chemistry and Molecular Engineering College of Chemistry and Molecular Engineering Peking University Beijing 100871 P.R. China

Mass spectrometric behaviour of （R） -1- （ 4-alkylphenyl ） alcohols, 1- （4-alkoxylphenyl） alcohols, and 1- （4-alkylthiophenyl） alcohols were studied with the aid of mass-analyzed ion kinetic energy spectrometry under electron impact ionization. All the title compounds show a tendency to eliminate a water molecule to form alkene ions and undergo an a-cleavago to produce protonated aldehyde ions by the loss of alkyl radicals. Except these two common fragment ions, they also show some different fragmentations due to with or without oxy/thioether-linkage.

关键词： 1-(4-Alkylphenyl) alcohol 1-(4-Alkoxylphenyl) alcohol 1-(4-Alkylthiophenyl) alcohol Electron impact ionization Fragmentation mechanism Mass spectrometry

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Change in relative density of WC-Co cemented carbides in spark plasma sintering process

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Rare Metals 2008年第1期27卷 74-77页

作者： SUN Lan LIN Chenguang jia Chengchang jia xian xian Mina School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China School of Manufacturing Science and Engineering Sichuan University Chengdu 610065 China Powder Metallurgy and Special Materials Department General Research Institute for Nonferrous Metals Beijing 100088 China

The relative density of WC-Co cemented carbides during spark plasma sintering（SPS） was *** on the change in displacement of the ram in the SPS system,the relative densities in the sintering process can be achieved at different *** results indicated that densification of the samples started at near 900°C,the density rapidly reached its maximum at the increasing temperature stage,in which the temperature was lower than the sintering temperature of 1200°C,and most of the densification took place in the ***,the theoretical values were consistent with the experimental results.

关键词： spark plasma sintering relative density WC-Co cemented carbides

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Incentive Mechanism Design for Public Goods Provision:Price Cap Regulation and Optimal Regulation

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Wuhan University Journal of Natural Sciences 2005年第5期10卷 817-822页

作者： ZHENG Jun-jun YIN Hong WANG xian-jia Systems Engineering Institute Wuhan University Wuhan 430072 Hubei China School of Business Wuhan University Wuhan 430072 Hubei China School of Business East China Normal University Shanghai 200062 China

This paper studies the mechanism design that induces firms to provide public goods under two regulatory means： price cap regulation and optimal regulation, respectively. We first outline two models of monopoly regulation with unobservable marginal costs and effort, which can be regard as an optimal problem with dual restrictions. By solving this problem, we get the two optimal regulatory mechanisms to induce the provision of public goods. Further, by comparative statics, the conclusion is drawn that the welfare loss as sociated with price cap regulation, with respective to optimal regulation, increases more with increase of the expense of public goods.

关键词： price cap regulation optimal regulation public goods incentive mechanism

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The applications of Schiff bases in Ti-catalyzed asymmetric alkynylation of aldehydes

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Chinese Chemical Letters 2007年第3期18卷 275-278页

作者： xian jia Lu Yin Xuan Zhao Xing Shu Li School of Pharmaceutical Engineering Shenyang Pharmaceutical University Shenyang 110016 China School of Pharmaceutical Sciences Sun Yat-Sen University Guangzhou 510080 China

Sciff bases 1 and 2, .which were derived from chiral aminoalcohols, were used as figands in Ti-catalyzed asymmetric alkynylation of aldehydes. Good enantioselectivities （up to 88% ee） and high chemical yields （80-... 详细信息

关键词： Stiff bases Ti-catalyzed Alkynylation

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