两两NQD列的完全收敛性的一个注记

讨论了包含两两NQD列的一类随机变量序列的完全收敛性,取消了王岳宝等讨论两两NQD列时的附加条件*(1)<1.     

系数或系数的模为两两NQD列的随机Dirichlet级数的收敛性

本文研究了两两NQD列的一些极限性质,推广了Borel-Cantelli引理、三级数定理、强大数定律,利用已有的两两NQD列的相关理论,获得了系数(或系数的模)为两两NQD序列的随机Dirichlet级数的收敛横坐标的简洁公式,以及类似于两两独立序列的相关结果.     

两两NQD序列与随机Dirichlet级数

本文研究了一类两两NQD序列加权乘积和的Jamison型强稳定性.利用两两NQD序列的一些极限理论,获得了系数的模为两两NQD列的一类随机Difichlet级数的增长性和值分布的一些新的结果,推广和改进了两两独立序列的相关结论.     

关于不同分布两两NQD列的Jamison型加权乘积和的强稳定性

本文讨论了不同分布两两NQD列的Jamison型加权乘积和的强稳定性及乘积和的Marcinkiewicz型强大数律,推广并改进了Etemadi[1]关于不同分布两两独立列部分和的工作及Matula[2],王岳宝等[3]关于同分布两两NQD列部分和的工作.     

一类两两NQD列乘积和的Jamison型强稳定性

研究了一类不同分布两两NQD列的Jamison型加权乘积和的强稳定性,推广了不同分布独立列部分和与同分布NQD列部分和情形相类似的结论.     

两两NQD阵列加权乘积和的完全收敛性和强大数定律

利用截尾法和两两NQD列部分和矩不等式,得到了两两NQD阵列加权乘积和的强大数定律,并在h-可积条件下给出了其完全收敛性的一个充分条件.     

两两NQD列大数定律的一个注记

利用两两NQD列三级数定理的思想和Chebyshev不等式,研究了两两NQD列在一类广泛条件下的弱大数定律和一类加强条件下的强大数定律,得到了与独立情形一致的结果,还特别讨论了同分布情形,推广了相关文献的结果．     

两两NQD列的两个极限定理

本文研究了两两NQD列的Lp收敛性和完全收敛性,改进了前人的相应结果.     

系数的模为两两NQD序列的随机幂级数的增长性

本文研究了系数的模为两两NQD序列的B-值随机幂级数的增长性.利用两两NQD列推广的Borel-Cantelli引理及其它极限定理，在给定条件下得出其增长级和非随机幂级数的增长级有类似的性质.     

两两NQD列的广义Jamison型加权和的强收敛性

讨论了两两NQD列的广义Jamison型加权的强收敛性,推广了名的Jamison定理。     

Boundary-Value Problems of the Theory of Thin and Nonthin Orthotropic Shells with Account of Nonlinearly Elastic Properties and Low Shear Rigidity of Composite Materials

The basic geometric and physical relations and resolving equations of the theory of thin and nonthin orthotropic composite shells with account of nonlinear properties and low shear rigidity of their materials are presented. They are derived based on two theories, namely the theory of anisotropic shells employing the Timoshenko or Kirchhoff-Love hypothesis and the nonlinear theory of elasticity and plasticity of anisotropic media in combination with the Lagrange variational principle. The procedure and algorithm for the numerical solution of nonlinear (linear) problems are based on the method of successive approximations, the difference-variational method, and the Lagrange multiplier method. Calculations of the stress-strain state for a spherical shell with a circular opening loaded with internal pressure are presented. The effect of transverse shear strains and physical nonlinearity of the material on the distribution of maximum deflections and circumferential stresses in the shell, obtained according to two variants of the shell theories, is studied. A comparison of the results of the problem solution in linear and nonlinear statements with and without account of the shell shear strains is given. The numerical data obtained for thin and nonthin (medium thick) composite shells are analyzed.     

Effects of permeability and viscosity in linear polymeric gels

We propose and analyze a mathematical model of the mechanics of gels, consisting of the laws of balance of mass and linear momentum of the polymer and liquid components of the gel. We consider a gel to be an immiscible and incompressible mixture of a nonlinearly elastic polymer and a fluid. The problems that we study are motivated by predictions of the life cycle of body‐implantable medical devices. Scaling arguments suggest neglecting inertia terms, and therefore, we consider the quasi‐static approximation to the dynamics. We focus on the linearized system about stress‐free states, uniform expansions, and compressions and derive sufficient conditions for the solvability of the time‐dependent problems. These turn out to be conditions that guarantee local stability of the equilibrium solutions. We also consider non‐stress free equilibria and states with residual stress and derive an energy law for the corresponding time‐dependent system. The conditions that guarantee stability of solutions provide a selection criteria of the material parameters of devices. The boundary conditions that we consider are of two types, displacement‐traction and permeability of the gel surface to the fluid. We address the cases of viscous and inviscid solvent, assume Newtonian dissipation for the polymer component, and establish existence of weak solutions for the different boundary permeability conditions and viscosity assumptions. We present two‐dimensional, finite element numerical simulations to study stress concentration on edges, this being the precursor to debonding of the gel from its substrate. Copyright © 2015 John Wiley & Sons, Ltd.     

乡村绿色生态旅游适宜等级VIKOR评估方法

针对乡村绿色生态旅游特征,并考虑旅游者个体感受与群体效益,本文从乡村绿色生态旅游开发与适宜评级概念出发,提出乡村绿色生态旅游适宜等级VIKOR评估模型与方法。首先,从等级评估的概念与内涵出发,刻画乡村绿色生态旅游适宜评级问题,避免混淆旅游适宜评级和排序两个本质不同的问题。然后,构建乡村绿色生态旅游适宜等级评估指标及隶属函数,提出评估指标的熵权确定方法。其次,提出乡村绿色生态旅游适宜等级VIKOR评估模型与二元语义等级评估方法。最后,通过案例研究和比较分析,说明本文所提模型与方法的合理性、可行性与实用性。     

非线性优化方法在大气和海洋科学数值研究中的若干应用

控制大气和海洋运动的模式是复杂的非线性模式,在考虑到线性奇异向量和线性奇异值只能描述切线性模式有效时段内小扰动发展的情况下,介绍了作者们近年来用非线性优化方法数值研究大气和海洋科学的有关工作,其中包括非线性奇异向量和非线性奇异值、条件非线性最优扰动、以及它们在数值天气和气候可预报性研究中的应用．结果表明,上述非线性优化方法在很大程度上揭示了大气和海洋运动的非线性特征;此外,对可预报性问题的新分类也做了详细介绍,即最大可预报时间、最大预报误差和最大允许初始误差A·D2这种分类的应用背景是针对数值天气预报和气候预测产品的评价;最后,讨论了数值模式敏感性分析的非线性优化方法,该方法在一定条件下可以定量识别模式误差和初始误差,量化判断数值模式的模拟能力．     

A 3D modeling of static and forward smoldering combustion in a packed bed of materials

A three-dimensional (3D) model based on the first principles of mass, momentum and energy was developed that numerically simulates the processes of static and forward smoldering in a porous packed bed of plant materials. The packed bed contains cellulose material or tobacco (cigarette) wrapped in a porous paper and surrounded by an ambient air. Other major characteristics of the model are including the effects of buoyancy forces in the flow field, separate treatment of solid and gas in a thermally non-equilibrium environment, and use of multi-precursor kinetic models for the pyrolysis of staring material and oxidation of char. The changes in porosity due to pyrolysis and char oxidation and the effect of porosity on the bed permeability and gas diffusivity are included. The mass, momentum, energy, and species transport equations are solved in a discretized computational domain using a commercially available computational fluid dynamics (CFD) code. The simulation results show that the model reasonably reproduces the major features of a burning cigarette during smoldering and puffing and are in a good agreement with the existing experimental results for cigarettes. Results include the velocity profiles, gas and solid temperatures, coal shape, burn rates, profile and transport of gas and vapor species throughout the packed bed, dilution through the wrapper paper and ventilation in the filter section, and the mass fraction of some pyrolysis and oxidation products in the mainstream and sidestream flows.     

我国经济产出与钢社会蓄积的关联分析

基于动态物质流分析方法及时间序列分析方法,本文以我国1949-2012年年度数据为样本,研究了工业化演进过程中我国经济产出与钢社会蓄积之间的关联。研究结果表明,随着经济的发展和工业化进程的演进,钢以实物产品的形式不断蓄积于我国社会当中,且蓄积的速度不断加快。我国经济产出与钢的社会蓄积之间存在长期协整关系,钢的社会蓄积既能在短期内推动经济的增长,又影响着经济产出的长期整体走势,而经济产出只是钢社会蓄积变化的长期原因。这说明我国的经济建设高度依赖钢的使用,而且经济增长对钢需求的拉动是一个长期的过程,不会在短期内对钢的需求造成显著影响。     

网约车新政下平台和乘客的Stackelberg博弈模型及策略研究

近年来,滴滴和优步等网约车平台的出现给城市居民出行带来了新的选择,然而随着新政的实施以及垄断巨头的酝酿诞生,网约车平台是否会降补贴提车价成为消费者最为关心的问题。文章构建网约车平台和乘客之间的Stackelberg博弈模型,分析了网约车平台的补贴和抽成策略对乘客是否选择网约车出行的决策行为以及网约车市场均衡的影响。理论研究和仿真结果表明:网约车平台合理的补贴力度和抽成力度可以有效规避行政监管成本增加和乘客资源流失的风险,提高双方的收益,实现社会的帕累托最优。     

基于关系契约视角的农户与农产品电子商务企业合作机制演化博弈分析

本文基于关系契约的视角,运用演化博弈理论,构建有限理性特性下的农户与农产品电子商务企业合作演化博弈模型,分析双方合作策略的演进过程、稳定策略及其影响因素,并通过Matlab仿真模拟分析影响双方合作策略选择的因素,验证博弈结果正确性。研究结果表明:农户和农产品电子商务企业选择合作策略与合作投入成本、实现的超额收益密切相关,博弈初始状态、再交易成本、单方不合作获得的收益及违约罚金等因素影响系统的演化稳定结果。因此完善农户与农产品电子商务企业的合作机制,需要构建合理的利益分配机制、良好的关系治理机制、有效的监督和惩罚机制和信息共享、沟通与协调机制。     

基于尖点突变的知识应用过程中溢出效应研究

本文引入“知识浓度”和“知识应用速度”两个概念,利用知识稀释效应的系统动力方程解释知识溢出机理。从突变视角分析了知识溢出的突变特性,借鉴尖点突变理论对系统动力方程进行换元变换,建立了知识溢出状态的尖点突变模型,讨论了知识稀释系统控制因子的变化与知识溢出状态间的判定规则,说明了知识应用过程中知识溢出特性如突跳、滞后效应等特性及知识溢出态和接受态之间转化的尖点突变机理。最后,利用我国31个省级行政区面板数据进行实证研究,揭示以省级行政区为对象的知识溢出状态、变化情况及发展趋势,为我国区域经济发展和知识战略提供理论指导。     

Interpreting linear systems of equalities and inequalities. Application to the water supply problem

This paper shows how the mathematical and the engineering points of view are complementary and help to model real problems that can be stated as systems of linear equations and inequalities. The paper is devoted to point out these relations and making them explicit for the readers to realize about the new possibilities that arise when contemplating the compatibility conditions or the set of general solutions from the dual perspective. After reviewing an orthogonally based powerful algorithm to analyse the compatibility of linear systems of equations and solving them, a water supply problem is used to illustrate its mathematical and engineering multiple aspects, including the optimal statement of the problem in terms of an adequate selection and numbering of equations and unknowns, an analysis of the compatibility conditions and a physical interpretation of the general solution, together with that of each individual generators of the affine space. The possibilities of removing unknowns without altering the compatibility of the problem is also analysed. Next, the Γ‐algorithm to analyse the compatibility of linear systems of inequalities and solving them is described and then, the water supply problem is revisited adding some constraints, such as capacity limits for the pipes and retention valves, and discussed as to how they affect the resulting general solution and other aspects. Finally, some conclusions are derived. Copyright © 2005 John Wiley & Sons, Ltd.