The Application of the Nehari Arguments to the Problems of the Existence about the Minimal Periodic Solutions of the Hamiltonian Systems

Using the Nehari argument about the constrained extreme values and the theorem that the functional defined on complete Finsler manifold and satisfying the Palais-Smale condition and having lower bound has a minimal value point,we study the existence of the minimal periodic solutions for nonconvex quadratic and superquadratic second order Hamiltonian systems.     

Forced Vibrad0ns of the Nth-Order Linear Neutral Dealy Differential Equations with Real Constant Coefficients

In this paper,we make an attempt to study forced vibrations of the nth-order linear neutral delay differential equations with real constant coefficients. Sufficient and necessary conditions of the existence and uniqueness of periodic solutions for the equations are obtained by use of theory of Pourier series. Furthmore ,some brief and practical critiria are given.     

An EOQ Model Taking Account of the Variable Selling Price Under Stock Dependent Selling Rate

In 1995, Padmanabhan and Vrat presented inventory models for deteriorating items with a constant selling price and stock dependent selling rate . Based on the result, in 2000, Kun-Jen Chung, Peter Chu and Shaw-Ping Lan devoloped the necessary and sufficient conditions of the existence and uniqueness of the optimal solutions of the profit per unit time functions without backlogging and with complete backlogging. Actually, the selling price need not be constant, it may be variable . This paper puts forward an EOQ model when the selling price is variable without backlogging, discusses the existence and uniqueness of optimum solution. The example is provided to illustrate the model. The theoretical evidence is provided for the inventory system to make management decision.     

The existence of limit cycles of some non-linear differential equations

The existence of limit cycles for the nonlinear oscillation equation is discussed, in which some hypothesis is omitted. The results of theorem 1 generalized the corresponding results for\.     

Generalized Nonlinear Set-valued Variational Inclusions Involving H-monotone Mappings

A new class of generalized nonlinear set-valued variational inclusions involving H-monotone mapping are introduced and studied. By using the properties of the resolvent operator associated with a H-monotone mappings in Hilbert spaces. An existence theorem of solution for the generalized nonlinear set-valued variational inclusions involving H-monotone mappings is established and a new algorithn is constructed. The author proves the iterative sequences generated by the algorithm strongly converge to its exact solution. Our results improve and generalized known corresponding and results.     

Existence of an Arbitrage about Portfolio in an Unequilibrium Market

This article has discussed the problem of an arbitrage about an portfolio in an unequilimarket and got a determinable theorem about existence of an arbitrage about an portfolio. According to this theorem,an arbitrage about portfolio is not existing if there exists a respect martignal measure.A structural result about existence of arbitrage about an portfolio in a market is gotten. All results represent the existence of an arbitrage about an portfolio is related closely to the type of market.     

Fixed Points on Complete Metric Spaces and Normed Linear Spaces

By properties of a real function, fixed points problem on two complete metric spaces are discussed.The result generalizes corresponding result of Fisher.Moreover, this result provides a general convergence rate estimate. Meanwhile, we discuss the existence of fixed point on two normed linear spaces under the condition of weak topology, and we obtain a new fixed point theorem.     

THREE CRITICAL POINTS THEOREM AND ITS APPLICATIONS

In this paper, by use of the pseudo-gradient vector field, the three critical points theorem in [2] is extended to the C1 function in the Ba-nach space, and therefore the three critical, points theorem in [5] is strengthened and the existence of the saddle point of the C2 function is discussed.     

Dual Theory of Nonsmcoth Multiobjective Programming with Set Functions

In this paper,for a nonsmooth multiobjective programming with set functions,Wolfe type duality and MondWeir type duality are established. Weak dual theorem,direct dual the-orem and in verse dual theorem about effictent solution are discussed.     

A METHOD OF SYSTEM IDENTIFICATION AND MODEL REDUCTION BASED ON TIME-DOMAIN RESPONSE OF A DYNAMIC SYSTEM

This paper combines model reduction with system identification by means of time-domain function approximation, and presents a new time domain method of direct identification of linear reduced model and model reduction, and demonstrates existence theorem of its solution and criterion of order determination. Simulation tests show that the method is simple, accurate with few data requirement.     

Application of Symmetric Galerkin Boundary Element Method in Limit Analysis of Plane Problems

Based on Melan's theorem, the symmetric Galerkin boundary element method (SGBEM) is used to discretize two dimensional structures and a computational formulation of structural limit analysis is established. The self equilibrium stress field is constructed by linear combination of several basic vectors, which are the stress differences between different iteration steps at the same increment using the traditional elastoplastic incremental method. Then the complex method is used to solve the nonlinear programming directly, so that the lower bound load multiplier of two dimensional structures is obtained. The validation of the present method has been confirmed by some numerical examples.     

A Method for Solving Strong Nonlinear Vibration

A method,stroboscopic harmonicbalance method which is used to solve strong nonlinear system, is proposed. The method is used to find the solution of strong nonlinear system. In investigation,the existence conditions of primary resonance solution and subharmonic resonance solutions are obtained. The results which are obtained by the stroboscopic harmonicbalance method are compared with those by computer numerical simulation. The results show that the stroboscopic harmonicbalance method is correct in qualitative analysis and it can meet the demands in engineering.     

EPQ Model with Different Lost Sale Factor Relative to Inventory Level

It is important for enterprises' inventory management to find out the optimal production cycle and the length of shortage time,so that the total cost of inventory system can be reduced and the service level can be raised.Based on the classical EPQ model,this paper develops an EPQ model for deterioration items with different lost sale factor relative to the inventory level during shortage period.The existence of unique optimal solution is discussed by mathematic analysis and a numeric example.The sensitivity analysis shows that the parameter of losing sale has different impact on the costs of inventory system.The factors must be considered for the production inventory system to make management decision.     

Screening techniques and sources of resistance to rusts and mildews in grain legumes

Summary In this paper we review the existence of sources of resistance and the various available screening methods for resistance in grain legumes against the airborne pathogens powdery mildews, downy mildews and rusts. Available resistance against these pathogens is not abundant and is particularly in risk of erosion owing to the constant generation and introduction of new races of the pathogen. A continuous search for more resistance sources is therefore a priority in legume breeding and special emphasis should be paid to selection of resistance mechanisms that are likely to be durable and to implementation of strategies to prolong the durability of existing resistance.     

Space,Time, and Local Employment Growth: An Application of Spatial Regression Analysis

ABSTRACT Local and regional employment growth is generally studied either by searching for local qualitative explanatory factors such as governance, synergy between firms, and milieu effects, or by searching for general growth factors using statistical techniques. The body of work that relies on this approach has tended, in keeping with economics’ nomothetic tradition, to assume that local and regional growth factors are constant over space. The focus of this paper is on exploring the spatial stationarity of employment growth factors in Canada, but it also seeks to clarify some of the broad principles behind spatial regression techniques in order to provide a point of entry and a conceptual framework for empirical researchers. To do so, we apply a recently developed technique, Geographically Weighted Regression (GWR), and we explore the method's advantages and limits for answering our research question. We find evidence that growth factors differ across Canada, but we also conclude that the GWR technique, given the number and shape of regions available for our analysis and given certain limitations that are currently inherent to the method, can only provide tentative and exploratory results.     

Plastic slip stability analysis of gangue granular media

This paper studies the landslide mechanism by the analysis of accumulation form, topography and geomorphology, self structure and natural river system of Weijiagou coal gangue hill. The limit state function is established based on plasticity mechanics limit analysis upper bound theorem and Bishop slices method, combining reliability theory. The safety coefficient and reliability index of Weijiagou coal gangue slope is calculated. The plasticity limit analysis upper bound theorem can consider the interior stress strain relation of soil, so the formula derivation process is stricter. It is the consideration of the variability of gangue parameters that making the evaluation result more reasonable.     

从拮抗枯萎病的香蕉植株中分离内生细菌的研究初报

香蕉枯萎病已成为香蕉产业的毁灭性病害,近年在中国的香蕉主要区迅速蔓延,目前还未找到有效的解决措施。在海南枯萎病严重发病多年的香蕉园中,发现在严重感病致死的植株包围中,存在着能正常挂果并成熟的植株。由于它们在品种上的相同性,因此从品种的差异上难以解释该现象。分离了其中的内生微生物,发现其中的内生微生物主要以细菌为主,一部分细菌能分泌几丁质酶,对病原菌有一定的拮抗性,尤其在香蕉杆浸出汁培养基中对病原菌的生长有一定抑制作用。这为香蕉枯萎病的生物防治提供了一条较好的思路。     

Existence and Stability of Periodic Solutions for Reaction-diffusion Systems with Time Delays

Periodic solutions of reaction-diffusion systems with time delays are investigated. It is constructed that the - per and lower control function of nonmonotone reaction term, and it is showed that the function satisfies a global Lipschitz condition and quasimonotone. A sort of effective method of studying differential equation with nonmonotone reaction term is gained. By using the method of upper and lower solutions and fixed point theorem, it is shown that periodic solutions of this system exist when reaction-term is not monotone and the boundary value system has a pair of coupled-upper and lower solutions. Some methods for proving the stability of the periodic solution are also given. And some known resuits are extended.     

Asymptotic Attractors of the Nonlinear Evolution Equation in Bounded Domain

The basic principle of infinite-dimensional dynamic system is to try to reduce the original infinite-dimensional system to an infinite-dimensional system. However,due to the unknown structure of the reduced system, it is difficult to describe its dynamical behaviour. To overcome this difficulty, the idea of approximate inertial manifolds is introduced, for NSE, the existence of AIM was studied, it is shown that the global attractor lies within a neighborhood of the graph of an Lipschitz function by the squeezing property. In this paper, by constructing a finite dimensional solution sequence, we will prove that it tends to the global attractor, theoretically, this provides a metod of constructing the asymptotic attractors, theoretically, this provides a method of constructing the asymptotic attractors for the evolution equations.     

NaCl和KCl溶液康普顿散射的影响因素

自康普顿散射提出以来,其理论研究和应用研究一直是国内外的热点。基于NaCl和KCl溶液的康普顿散射,通过一定的近似处理,从理论上分析适合这两种溶液的康普顿散射光子数与溶液浓度之间的关系表达式;然后,通过康普顿散射实验验证康普顿散射的理论和实验研究。为了从更微观的角度来把握NaCl和KCl溶液康普顿散射的机理,笔者立足于密度泛函理论对NaCl与KCl溶液的电子结构作了深入分析,得出结论:除质量密度、散射衰减因子以及溶液的浓度外,电子数密度和电子受到的束缚也对康普顿散射光子数有影响,其中,电子数密度是影响NaCl与KCl溶液康普顿散射光子数的主要因素。