Switching effect on a two prey-one predator system with strong Allee effect incorporating prey refuge

In an environment,the food chains are balanced by the prey-predator interactions.When a predator species is provided with more than one prey population,it avails the option of prey switching between prey species according to their availability.So,prey switching of predators mainly helps to increase the overall growth rate of a predator species.In this work,we have proposed a two prey-one predator system where the predator population adopts switching behavior between two prey species at the time of consumption.Both the prey population exhibit a strong Allee effect and the predator population is considered to be a generalist one.The proposed system is biologically well-defined as the system variables are positive and do not increase abruptly with time.The local stability analysis reveals that all the predator-free equilibria are saddle points whereas the prey-free equilibrium is always stable.The intrinsic growth rates of prey,the strong Allee parameters,and the prey refuge parameters are chosen to be the controlling parameters here.The numerical simulation reveals that in absence of one prey,the other prey refuge parameter can change the system dynamics by forming a stable or unstable limit cycle.Moreover,a situation of bi-stability,tri-stability,or even multi-stability of equilibrium points occurs in this system.As in presence of the switching effect,the predator chooses prey according to their abundance,so,increasing refuge in one prey population decreases the count of the second prey population.It is also observed that the count of predator population reaches a comparatively higher value even if they get one prey population at its fullest quantity and only a portion of other prey species.So,in the scarcity of one prey species,switching to the other prey is beneficial for the growth of the predator population.

Distributed Nash Equilibrium Seeking on Compact Action Sets over Jointly Strongly Connected Switching Networks

This paper studies the distributed Nash equilibrium seeking(DNES)problem for games whose action sets are compact and whose network graph is switching satisfying the jointly strongly connected condition.To keep the actions of all players in their action sets all the time,one has to resort to the projected gradient-based method.Under the assumption that the unique Nash equilibrium is the unique equilibrium of the pseudogradient system,an algorithm is proposed that is able to exponentially find the Nash equilibrium.Further,the authors also consider the distributed Nash equilibrium seeking problem for games whose actions are governed by high-order integrator dynamics and belong to some compact sets.Two examples are used to illustrate the proposed approach.

Modification of rock mass rating system:Interbedding of strong and weak rock layers

Rock mass classification systems are the very important part for underground projects and rock mass rating(RMR) is one of the most commonly applied classification systems in numerous civil and mining projects. The type of rock mass consisting of an interbedding of strong and weak layers poses difficulties and uncertainties for determining the RMR. For this, the present paper uses the concept of rock bolt supporting factor(RSF) for modification of RMR system to be used in such rock mass types. The proposed method also demonstrates the importance of rock bolting practice in such rock masses. The geological parameters of the Shemshak Formation of the Alborz Tunnel in Iran are used as case examples for development of the theoretical approach.

ON NUMBER OF LIMIT CYCLES FOR THE QUADRATIC SYSTEMS WITH A WEAK FOCUS AND A STRONG FOCUS

It is proved that the quadratic system with a weak focus and a strong focus has at most one limit cycle around the strong focus, and as the weak focus is a 2nd order(or 3rd order) weak focus the quadratic system has at most two(one) limit cycles which have (1,1) distribution ((0,1) distribution).

Global existence of weak solutions to a prey-predator model with strong cross-diffusion

Using finite differences and entropy inequalities, the global existence of weak solutions to a multidimensional parabolic strongly coupled prey-predator model is obtained. The nonnegativity of the solutions is also shown.

Strong/weak limits and strong/weak differentials of multi-variable indeterminate forms. I: Deduction and geometric illustration

Strong and weak limits as well as strong and weak differentials of multi-variable indeterminate forms are discussed based on the thorough exploration of differentiation to solve the strong and weak limits and differentials of unitary indeterminate forms. The fruit of this work is going to be reported in three parts. The first part presents the standard analysis on this subject which supplements, systematizes and advances L. Hospital抯 principles on differential calculus by applying special ,general, and limit guaranteeing theories together with K(t) and XhK0 theories. The combination of theoretical analysis and geometric signification makes the derivation intuitional, visual and easy to perceive.

WEAKLY ALGEBRAIC REFLEXIVITY AND STRONGLY ALGEBRAIC REFLEXIVITY

Algebraic reflexivity introduced by Hadwin is related to linear interpolation.In this paper,the concepts of weakly algebraic reflexivity and strongly algebraic reflexivity which are also related to linear interpolation are introduced.Some properties of them are obtained and some relations between them revealed

Checking weak and strong optimality of the solution to interval convex quadratic program

In this paper,we investigate three canonical forms of interval convex quadratic pro-gramming problems.Necessary and suficient conditions for checking weak and strong optimality of given vector corresponding to various forms of feasible region,are established respectively.By using the concept of feasible direction,these conditions are formulated in the form of linear systems with both equations and inequalities.In addition,we provide two specific examples to illustrate the efficiency of the conditions.

Strong and Weak Property of Travelling Wave Front Solutions for a Class of Degenerate Parabolic Equations

In this paper we study the strong and weak property of travelling wave front solutions for a class of degenerate parabolic equations. How the strong and weak property changes under the effects of wave speed and reaction diffusion terms are showed.

Key Technical Points of Wheat Moisture-resistant Strain Sowing and Management of Promoting Seedlings from Weak to Strong in Daiyue District

According to the meteorological conditions of sowing period and the characteristics of seedling in each key growth period,the measures of rushing drainage,rushing harvest stubble,rushing sow,implementing late sowing,strengthening field management before winter and in spring are taken in Daiyue District during the autumn planting period of wheat,which reduce the influence of natural disasters and increase the yield of wheat.

DIRECT TITRATION OF VERY WEAK ACIDS(BASES)IN AQUEOUS SOLUTION WITH STRONG BASES(ACIDS)USING VISUAL END-POINT INDICATION WITHOUT INDICATOR

This paper reports a new method of titration for very weak acids and bases using the appearance of incisions on oscillopolarogram to indicate the end-point.This method has the advantages of rapidity,simplicity,no indicator needed as well as good precision.

INTERACTION OF STRONG AND WEAK SINGULARITIES FOR HYPERBOLIC SYSTEM OF CONSERVATION LAWS IN MULTIDIMENSIONAL SPACE

In this paper we study the interaction of strong and weak singularities for hyperbolic system of conservation laws in multidimensional space. Under the assumption of transversal intersect of the shock front with the bicharacteristics bearing weak singularities we proved a theorem on regularity propagation across the shock front.

Analysis on Chinese/English Code-Switching in Computer-Mediated Communication Based on Meme Theory

Nowadays,computer-mediated communication(CMC) becomes one of the most convenient ways for people to connect with each other in which Chinese/English code-switching has been frequently used and widely spread.The article will memeticly interpret this language phenomenon based on the authentic examples collected from various kinds of CMC,and point out that the Chinese/English code-switching in CMC is a kind of strong memeplex which includes many different strong memes,resulting in the popularity of Chinese/English code-switching in CMC.

部分包覆钢-混凝土组合梁柱节点抗震性能试验研究

为研究不同连接构造的部分包覆钢-混凝土组合梁柱节点(PEC梁柱节点)的抗震性能,对2个PEC梁柱节点试件进行了拟静力加载试验,研究了低周往复荷载作用下PEC梁柱节点试件的破坏现象、滞回曲线、骨架曲线、延性、耗能能力和刚度退化等抗震性能。结果表明:强轴连接PEC梁柱节点的滞回曲线呈梭形和弓形,在达到极限承载力后仍能保持一定的延性和耗能能力;弱轴连接PEC梁柱节点牛腿与梁间的焊缝处发生破坏,未展现出预期的耗能能力,PEC梁仍在弹塑性状态,没有达到极限状态;PEC梁柱节点核心区混凝土替换为加劲肋板后,试件仍具有较好的承载力、延性和耗能能力,刚度退化规律无明显变化,且强轴连接节点与弱轴连接节点刚度变化规律基本一致;PEC柱牛腿设计过短会导致焊缝连接处断裂,试件延性和耗能能力得不到发挥,剩余刚度较大。

鄂尔多斯盆地本溪组碎屑障壁海岸砂体微相南北变化

在延长探区近1500口钻井资料的基础上,进行大量岩心和薄片观察以及砂厚和砂地比统计,探究鄂尔多斯盆地本溪组的砂体微相类型、平面形态和分布的沿岸变化及其控制因素。结果表明,延长气田本溪组总体均为中小潮差环境下的陆源碎屑障壁海岸沉积,但南部的甘泉—富县地区波浪作用较弱,形成了典型的障壁砂坝和障壁后沉积。北部延安—靖边南地区波浪作用较强,形成了改造障壁、浅滩和下切谷充填潮道3种主要微相砂体。障壁砂体呈平行岸线的带状或串珠状排列,近源和近岸分布;浅滩砂体呈多个分散的卵圆形远源远岸分布;潮道带砂体充填则受控于古地貌凹槽。该研究结果对延长气田和类似环境的储层识别和评价具有重要的指导意义。

“组强村弱”结构下的征地博弈及启示--基于赣西H村的考察

延续既有征地研究中利益博弈的视角,研究发现“村庄治理结构”是影响征地博弈样态的独立因素。区别于将行政村默认为利益博弈中的村级主体,研究关注“组强村弱”治理结构下小组作为博弈主体的征地实践。基于赣西H村的实证分析发现,“组弱村强”治理结构的产生与村庄分布形态、宗族认同和土地集体所有等因素有关。它对征地博弈的影响在于:对外博弈中,小组因一致行动能力而具备更强的议价能力;在组内博弈中,小组具备排除行政能力干预、自主决定利益分配的空间,这种宽松的环境加剧了利益分化的群体之间的利益博弈。以小组为单位进行的双层博弈导致村庄公共利益消失、村庄认同弱化以及村庄矛盾激化等一系列后果,动摇了村社共同体的根基,由此产生的纠纷矛盾对基层治理能力提出挑战。

FT-粗糙集模型的一些性质

T-粗糙集是Pawlak粗糙集理论发展过程中的一个重要模型,已成功应用于数据挖掘等诸多领域.FT-粗糙集模型能够在保持数据的完整性下处理连续型数据,是对仅能处理离散型数据的T-粗糙集模型上的发展.文章引入模糊近似空间(X,Y,T)一对模糊集的弱逆和强逆定义,用量化方法研究FT-粗糙集的一些性质,得到模糊技能映射在析取模型、合取模型下分别生成的知识结构;用量化方法与矩阵表示探究FT-粗糙集模糊集值映射在并、交运算下的性质.

冀东金厂峪金矿剪切带控矿规律及找矿建议

冀东金厂峪金矿为典型受构造作用控制的矿床,金矿体主要产于NNE向脆-韧性片理化带内的强变形带之中,直接控矿构造为叠加于强变形带之上的NNE向燕山期脆性断裂构造。本文在详细的野外调查基础上进行了构造分期配套,建立了弱变形域控岩+强变形带赋矿的透镜体控矿模式,结合矿体赋存和矿化富集规律总结,提出了韧脆性片理化带深部、两侧次级平行构造等找矿方向。

中国竞技篮球风格的守正与创新—兼论中国男篮竞技水平提升策略

秉持守正创新原则探讨中国竞技篮球风格,旨在探索中国竞技篮球高质量发展路径。对中国竞技篮球传统中的“以弱胜强”理念进行考辨,认为“以弱胜强”突出强调“立足弱队”与“敢打必胜”的辩证统一,是关于中国竞技篮球最为根本独到、积极有为的认知定位和策略思想。运用“快”与“变”的动力学核心观点阐述“在快速基础上以变打快”的逻辑创新,认为“在快速基础上以变打快”必须置于高质量对抗条件下。由之,形成可有效统摄现有表述的中国竞技篮球风格新构念:以弱胜强,在快速基础上、高质量对抗条件下以变打快。围绕新构念的实践深化,探讨中国男篮的技战术打法创新、竞技保障建议和精神面貌臧否。