浅谈cover在外贸英语中的应用

在外贸英语函电中,我们时常看到cover一词,其用处极广,表达的意思各不相同。在一般的词典中我们还查不到该词的一些特定意思。本文就cover一词在外贸英语中作为名词,动词的用法和意义做了较为详细的介绍,并列举了大量的例句。也较为详细地介绍了其相关词的各种用法和意义,详细列举了该词和其它词构成的外贸英语特定词组。以便使读者对该词有更深的了解,更恰当的运用。     

论病情保密的弊端

文章针对危重病人或预后不良的病人,从病情保密对病人作用的双重性入手,在肯定其某种积极作用的同时,着重分析并指出病情保密和隐瞒的种种弊端.     

A PTAS for a disc covering problem using width-bounded separators

In this paper, we study the following disc covering problem: Given a set of discs of various radii on the plane and centers on the grid points, find a subset of discs to maximize the area covered by exactly one disc. This problem originates from the application in digital halftoning, with the best known approximation factor being 5.83 (Asano et al., 2004). We show that if their radii are between two positive constants, then there exists a polynomial time approximation scheme. Our techniques are based on the width-bounded geometric separator recently developed in Fu and Wang (2004), Fu (2006). This research is supported by Louisiana Board of Regents fund under contract number LEQSF(2004-07)-RD-A-35.     

China＇s Ranking Rises in the Mothers＇ Index

正On May 6,2014,Save the Children,an international charity,issued its report of State of the World's Mothers 2014.Among the Mothers’Index covering178 countries in the world,China ranks the 61st,an increase of 7 positions over the previous year.This is the 15th year     

旱地大绿豆不同覆盖方式试验研究

为了保蓄旱地土壤水分，减少无效蒸发，从而提高旱地土壤水分利用率，我们采用地膜、生物二元和单元覆盖方式进行试验研究，探求绿豆抗旱增产增收新途径。     

实数完备性基本定理的相互证明

本文由直接相互推证的方法给出了实数完备性定理的等价性证明.     

On Split-Coloring Problems

We study a new coloring concept which generalizes the classical vertex coloring problem in a graph by extending the notion of stable sets to split graphs. First of all, we propose the packing problem of finding the split graph of maximum size where a split graph is a graph G = (V,E) in which the vertex set V can be partitioned into a clique K and a stable set S. No condition is imposed on the edges linking vertices in S to the vertices in K. This maximum split graph problem gives rise to an associated partitioning problem that we call the split-coloring problem. Given a graph, the objective is to cover all his vertices by a least number of split graphs. Definitions related to this new problem are introduced. We mention some polynomially solvable cases and describe open questions on this area. An erratum to this article is available at .     

基于时间满意的最大覆盖选址问题

传统的选址问题过于简单地考量时间这一对企业竞争力影响重大的因素,结合这一特点,本文对时间满意度函数进行了定义并提出了基于时间满意的最大覆盖选址问题。给定的网络G(V,A)中,在总的顾客对服务站响应速度的满意程度最大的目标下建立了最大覆盖选址问题模型,我们在讨论了问题的特点之后给出了基于拉格朗日松驰的启发式算法,并通过MATLAB进行了编程计算实验,分析了实验结果。     

Modeling the problem of locating collection areas for urban waste management. An application to the metropolitan area of Barcelona

Reverse logistics problems arising in municipal waste management are both wide-ranging and varied. The usual collection system in UE countries is composed of two phases. First, citizens leave their refuse at special collection areas where different types of waste (glass, paper, plastic, organic material) are stored in special refuse bins. Subsequently, each type of waste is collected separately and moved to its final destination (a recycling plant or refuse dump). The present study focuses on the problem of locating these collection areas. We establish the relationship between the problem, the set covering problem and the MAX-SAT problem and then go on to develop a genetic algorithm and a GRASP heuristic to, respectively, solve each formulation. Finally, the quality of the algorithms is tested in a computational experience with real instances from the metropolitan area of Barcelona, as well as a reduced set of set covering instances from the literature.