具有delta-激波的非线性双曲守恒定律的初边值问题

For a nonlinear hyperbolic system of conservation laws, the initial-boundary value problem is concerned with the boundary conditions. A boundary entropy condition is derived based on Dubois F and Le Floch P＇s results by taking a suitable entropy-flux pair （Journal of Differential Equations, 1988, 71（1）： 93-122）. The solutions of the initial-boundary value problem for the system are constructively obtained, in which initial-boundary data are in piecewise constant states. The delta-shock waves appear in their solutions.     

关于无粘可压绝热流体的欧拉方程不适定初边值问题的形式解

It is proved that the ill-posed initial value problem of the Euler equations for compressible adiabatic inviscid fluid flow can be only formally solved. The necessary and sufficient conditions for existence of formal solution of some representative ill-posedness initial-boundary value problem are presented. Finally, an example is also given.     

求非线性整数规划的逐次下降方法

In this paper, a new method named as the gradually descent method was proposed to solve the discrete global optimization problem. With the aid of an auxiliary function, this method enables to convert the problem of finding one discrete minimizer of the objective function f to that of finding another at each cycle. The auxiliary function can ensure that a point, except a prescribed point, is not its integer stationary point if the value of objective function at the point is greater than the scalar which is chosen properly. This property leads to a better minimizer of f found more easily by some classical local search methods. The computational results show that this algorithm is quite efficient and reliable for solving nonlinear integer programming problems.     

一个最简带粘性项的非凸ZND 燃烧模型的黎曼问题

In this paper, a simplest scalar nonconvex ZND combustion model with viscosity is considered. The existence of the global solution of the Riemann problem for the combustion model is obtained by using the fixed point theorem.     

Stylistic Analyses of Ramona Series by Beverly Cleary

Beverly Cleary is one of the most popular and honored writers of contemporary children’s fiction.Her Ramona series delight generations and strike root in the hearts of the people.Through stylistic analyses of the series by the depiction of Ramona’s characteristics,and Cleary’s special writing skills reveal the literary value of these books and Beverly’s legacy for children’s literature.     

A MATHEMATICAL MODEL FOR POWER PLANT HEATERS

This paper studies the modelling and simulation for all forms of hcaters.The assumption of former days that the temperature of condensation is the saturationtemperature corresponding to heater pressure in steam side is no longer used.On the basisof the laws of conservation of mass,energy and momentum,the mathematical model ofheaters is established and the simulation calculation of a 125MW unit is made.The rcsultshows that the model is applicable for various kinds of steam-water heater in power plant.     

Riemann problem of a Chapman-Jouguet combustion model for pressure-gradient system

In this paper,the Riemann problem of a Chapman-Jouguet combustion model for the pressure-gradient equations is considered.By analyzing in phase space,existence and uniqueness of the solution to the Riemann problem are obtained constructively under the global entropy conditions.     

Elastohydrodynamic Lubrication Studies on Effects of Crowning Value in Roller Bearings

The purpose of this paper is to present a comparison of numerical calculations and experiment results of optical interferometry in finite line contact for the elastohydrodynamic lubrication(EHL)problem of Lundberg‘s profiled cylindrical roller under the conditions of flooded state,moderate load and material parameter.It shows clearly the effects of crowning value on the variations of oil film shape and thickness.The agreement between numerical analysis and experiment results is very good.The results indicate there must be an optimum crowning value that will induce the thickest and most even oil film in EHL state for a given working condition,and this value is larger than the design value in dry contact state for the same working coditiona.     

Conservation laws for energy and momentum in curved spaces

In arbitrary Riemannian 4-spaces, continuity equations are constructed which could be interpreted as conservation laws for the energy and momentum of the gravitational field. Special attention is given to general relativity to obtain, of natural manner, the pseudotensors of Einstein, Landau-Lifshitz, Mller, Goldberg and Stachel, and also the conservation equations of Komar, Trautman, DuPlessis and Moss.     

Hawthorne's Short Stories:a Journey to Explore Evil

Hawthorne was a great writer who reminds us of human limitations.He called his tales "allegories of the heart." Hawthorne’s allegories are stories of how pride and isolation frustrate our capacity for love and sympathy.Isolation or "alienation" is Hawthorne’s principal theme and problem,and loss of contact with reality is the ultimate penalty he envisions.Therefore,reading Hawthorne’s stories is a journey to explore human being’s evil.     

EVA based model to estimate the Chinese listed company’s intrinsic value

1 Introduction a Evaluation and measurement of the value of an enterprise is still a puzzle in accounting circle. Many efforts have been directed in the past years to theoretical and empirical research on this problem. Economic value added (EVA) is one of the hot issues. Briefly speaking, the EVA is balance between company’s after-tax operation profit and capital cost; it is an economic profit concept after considering opportunity cost, not simply the accounting profit concept; it is the t…     

Nora's Possible Way Out——To See It through a Comparative Study between Nora and Kristine

Ibsen’s A Doll’s House is regarded as a kind of "canon". As the play shares an open ending, many critics seem to try to find a way out for Nora. Nora is supposed as the first woman to pronounce the "Women Declaration of Independence". She has become the most courageous women for fighting an equal place in family. However, this paper focuses mainly on the comparison between Nora and Kristine the relatively less popular character. Kristine plays a role of girlhood friend of Nora as well as the one who solves the debt problem and brings a new problem into Nora’s family. She serves a model for Nora. Ibsen writes Nora as she is, but it is Kristine who leads Nora onto the road of finding herself. Through the image of Kristine we can conclude that Nora might have all kinds road to tread before her but each one leads to a home-her true home.     

Interaction of elementary waves of scalar conservation laws with discontinuous flux function

1IntroductionConsider the scalar conservationlawsut (k(x)f(u))x=0,(1)where(x,t)∈R×R ,u(x,t)is a scalar unknownfunction,k(x)andf(u)are given functions andf″(u)>0.The conservation laws(1)occur in manymodels.Perhaps the si mplest case is the so-calledtraf…     

Quantitative information measurement and application for machine component classification codes

Information embodied in machine component classification codes has internal relation with the probability distribution of the code symbol. This paper presents a model considering codes as information source based on Shannon＇s information theory. Using information entropy, it preserves the mathematical form and quantitatively measures the information amount of a symbol and a bit in the machine component classification coding system. It also gets the maximum value of information amount and the corresponding coding scheme when the category of symbols is fixed. Samples are given to show how to evaluate the information amount of component codes and how to optimize a coding system.     

The Physics—Based Manifold Modeling Method for Free—form Surface Design

A new framework for free-surface design is proposed.Using Manifolds can generalize the spline scheme to surfaces of arbitrary topology,Physics-based modeling incorporate physical laws into shape representation to provide direct shape interaction.The combination presents a new method inherits the attractive properties of the manifold surface as well as that of the physcis-based models.     

关于简单线性恶化问题的平行机排序的一个全多项式逼近算法

In this paper, a parallel machine scheduling problem was considered , where the processing time of a job is a simple linear function of its starting time. The objective is to minimize makespan. A fully polynomial time approximation scheme for the problem of scheduling n deteriorating jobs on two identical machines was worked out. Furthermore, the result was generalized to the case of a fixed number of machines.     

A relaxation scheme for a multi-class Lighthill-Whitham-Richards traffic flow model

We present a high-resolution relaxation scheme for a multi-class Lighthill-Whitham-Richards （MCLWR） traffic flow model. This scheme is based on high-order reconstruction for spatial discretization and an implicit-explicit Runge-Kutta method for time integration. The resulting method retains the simplicity of the relaxation schemes. There is no need to involve Riemann solvers and characteristic decomposition. Even the computation of the eigenvalues is not required. This makes the scheme par- ticularly well suited for the MCLWR model in which the analytical expressions of the eigenvalues are difficult to obtain for more than four classes of road users. The numerical results illustrate the effectiveness of the presented method.     

Time Pressure Influence in Negotiation

With the development of economic globalization,international trade has taken a great part in business.While every negotiation is a trade,people doing business have to pay great attention to negotiation,if they want to be successful in the trading market.In short,negotiation is a bargaining process to achieve coincidence on a problem about every aspect of negotiation for assuring everyone’s needs.This essay’s topic is that time pressure’s influence in negotiation.Since the general introduction of negotiation has been discussed before,now the following will introduce time power in negotiation in detail.     

The Application of Mind Map in Junior English Vocabulary Teaching

Almost every English learners is impacted and harassed by word memory in different degrees.However,the traditional rote memorization that is commonly used by majority of students can exacerbate the problem.It is believed that Mind Map may contribute to enhancing the efficiency of vocabulary learning and enlarging the capacity of words.Therefore,Mind Map has received extensive attention in English vocabulary teaching for the recent decades.Mind Map is conducive to motivating student’s interest,enhancing students’memory and augmenting vocabulary learning efficiency.     

Quasilinear singularly perturbed problem with boundary perturbation

A class of quasilinear singularly perturbed problems with boundary perturbation is considered. Under suitable conditions, using theory of differential inequalities we studied the asymptotic behavior of the solution for the boundary value problem.