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Qun Liu Daqing Jiang Tasawar Hayat Ahmed Alsaedi 《Journal of The Franklin Institute》2018,355(16):8177-8193
In this paper, we propose and study a stochastic predator–prey model with herd behavior. Firstly, by constructing a suitable stochastic Lyapunov function, we establish sufficient conditions for the existence and uniqueness of an ergodic stationary distribution of the positive solutions to the model. Then we establish sufficient conditions for extinction of the predator population in two cases, that is, the first case is the prey population survival and the predator population extinction; the second case is all the prey and predator populations extinction. Finally, some examples together with numerical simulations are introduced to illustrate the theoretical results. 相似文献
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The existence and uniqueness of stationary distribution and ergodic properties of a stochastic system are obtained. Especially, different from the existing methods, a new method is introduced to analyze almost sure permanence and uniform boundedness of the stochastic predator–prey model. This new idea is based on geometric structure of invariant set for a stochastic system. More specifically, we obtain our main conclusions by showing the invariant set for the stochastic population system lies in the interior of the first quadrant. It is interesting and surprising that the stochastic population model can guarantee a uniform boundedness almost surely. Some numerical simulations are carried out to support our results. 相似文献
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In this paper, a hybrid triple delayed prey predator bioeconomic system with prey refuge and Lévy jumps is established, where both maturation delay for prey and predator population and gestation delay for predator population are considered. For deterministic system, positivity and uniform permanence of solution are discussed. Local stability of deterministic system around interior equilibrium is investigated due to variations of triple time delays. For stochastic system without time delay, sufficient conditions for stochastically ultimate boundedness and stochastic permanence are discussed. Existence of stochastic Hopf bifurcation and stochastic stability are investigated. For stochastic system with triple time delays, existence and uniqueness of global positive solution are studied. Finally, combined dynamic effects of triple time delays and Lévy jumps on the hybrid stochastic system are discussed by constructing appropriate Lyapunov functions. Numerical simulations are supported to illustrate theoretical analysis. 相似文献
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《中国科学院研究生院学报》2001,(1)
Ｔｈｅｓｅｐａｒａｔｉｏｎｏｆｅｎａｎｔｉｏｍｅｒｓ ,ｗｈｉｃｈｄｅｍａｎｄｓｈｉｇｈｓｅｎｓｉｔｉｖｉｔｙ ,ｈｉｇｈｓｅｌｅｃｔｉｖｉｔｙａｎｄｈｉｇｈｓｅｐａｒａｔｉｏｎｅｆｆｉｃｉｅｎｃｙ ,ｉｓｍａｉｎｃｈａｌｌｅｎｇｅｔｏｃｈｅｍｉｓｔｒｙ ,ｅｓｐｅｃｉａｌｌｙａｎａｌｙｔｉｃａｌｃｈｅｍｉｓｔｒｙ .Ｃｈｒｏｍａｔｏｇｒａｐｈｙｔｅｃｈｎｉｑｕｅｓ,ｉｎｃｌｕｄｉｎｇＨＰＬＣ ,ｔｈｉｎｌａｙｅｒｃｈｒｏｍａｔｏｇｒａｐｈｙ(ＴＬＣ) ,ｇａｓｃｈｒｏｍａｔｏｇｒａｐｈｙ(ＧＣ)ａｎｄｈｉｇｈｐ… 相似文献
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动词不定式与动名词都属非谓语动词,用法复杂且灵活,不受人称和数的限制.都可充当主语、表语、宾语、定语等,但也有不同,动词不定式还可作补语、状语,而动名词可作介词宾语、短语动词等.本文就它们在语法、词法、句子结构中的异同作了详尽的比较,提出此看法. 相似文献
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动词不定式与动名词都属非谓语动词,用法复杂且灵活,不受人称和数的限制。都可充当主语、表语、宾语、定语等,但也有不同,动词不定式还可作补语、状语,而动名词可作介词宾语、短语动词等。本文就它们在语法、词法、句子结构中的异同作了详尽的比较,提出此看法。 相似文献
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《国家科学评论(英文版)》2014,(4)
<正>he year 2014 may prove to be a major turning point in China’s development of world-class science and innovation system.At the mid-term juncture of China’s Medium-and Long-Term Program(MLP)for Science and Technology(ST)development,the Ministry of Science and Technology conducted a comprehensive review and assessment 相似文献
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YAN Jun 《中国科学院院刊(英文版)》2011,25(3)
This article elucidates the background and significance of astronomy, overviews the important progress over the past decade, and points out the main scientific problems for world astronomy. Based on a comparison between China＇s astronmical facilities, existing and in planing, and the major international facilities, the author proposes some strategies for promoting China＇s astronomy. 相似文献
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r Klaus Hahlbrock 《中国科学院院刊(英文版)》2004,(2)
The common goals and the almost perfect complement of the initiatives taken in parallel at Kunming and at several Max Planck sites could serve as valuable starting points for further promoting the CAS/MPS partnership in all matching areas of ecological research. 相似文献
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《中国专利与商标》2007,(4)
Both cancellation and invalidation of the trademark right cause termination of a trademark right.Most national trade- mark laws clearly distinguish the system of trademark can- cellation from that of trademark invalidation.In the current Chinese Trademark Law,however,the concept of"trade- mark right invalidation"is absent.Instead,the term of"can- cellation"is used to refer to the above two circumstances.In fact,"cancellation"as provided for in Article 41 of the 相似文献
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Contemporary ICTs such as speaking machines and computer games tend to create illusions. Is this ethically problematic? Is it deception? And what kind of “reality” do we presuppose when we talk about illusion in this context? Inspired by work on similarities between ICT design and the art of magic and illusion, responding to literature on deception in robot ethics and related fields, and briefly considering the issue in the context of the history of machines, this paper discusses these questions through the lens of stage magic and illusionism, with the aim of reframing the very question of deception. It investigates if we can take a more positive or at least morally neutral view of magic, illusion, and performance, while still being able to understand and criticize the relevant phenomena, and if we can describe and evaluate these phenomena without recourse to the term “deception” at all. This leads the paper into a discussion about metaphysics and into taking a relational and narrative turn. Replying to Tognazzini, the paper identifies and analyses two metaphysical positions: a narrative and performative non-dualist position is articulated in response to what is taken to be a dualist, in particular Platonic, approach to “deception” phenomena. The latter is critically discussed and replaced by a performative and relational approach which avoids a distant “view from nowhere” metaphysics and brings us back to the phenomena and experience in the performance relation. The paper also reflects on the ethical and political implications of the two positions: for the responsibility of ICT designers and users, which are seen as co-responsible magicians or co-performers, and for the responsibility of those who influence the social structures that shape who has (more) power to deceive or to let others perform. 相似文献
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We propose that the effect of trust on knowledge sharing (KS) and knowledge integration (KI) is mediated by organizational identification (OI) and organization-based self-esteem (OBSE). We focus on the relationship among different foci of trust and take into consideration that trust is a culturally dependent variable. We draw from a large-scale questionnaire survey with 50 Chinese companies and find support for our hypotheses in general. The study finds that employees’ trust within the organization is a multifaceted construct that includes their trust in the organization, trust in the supervisor and trust in peers. Trust with these different foci positively impact KS and KI. However, such effects are largely indirect and we find support for our expectation that OI and OBSE function as mediators. We conclude that trust in itself is a precondition but not sufficient condition for the actualization of KS and KI. 相似文献
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This literature review highlights some Social Network Analysis (SNA) concepts applicable to the study of organizational knowledge and, more particularly, to knowledge heterogeneity. Knowledge being all at the same time decentralized and distributed, knowing up to what point knowledge can be heterogeneous or homogeneous across organizational units becomes as important as the question of knowing how to structure the organization. SNA applied to knowledge management thus seems a stimulant for future research in the fields of management. 相似文献
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《中国专利与商标》2006,(4)
It is a relatively common phenomenon to limit technical features with parameter range in patent claims. It is argued in this article that the parameter range should be distinctly divided into single parameter range and whole parameter range depending on the different mode and function of limitation. Each and every parameter in a single parameter range may independently achieve a technical effect, and limit one embodiment alone; while a single parameter in the whole parameter range cannot independently achieve any technical effect, and the set of parameters as a whole within the parameter range limit a technical feature. Discrimination between the single parameter range and the whole parameter range has a bearing on the assessment of novelty and inventiveness. Owing to the absence of such discrimination of parameter range, the provisions of the current Guidelines for Examination on novelty and inventiveness of the claims relating to parameter range are not applicable to the circumstance of whole parameter range. 相似文献