这辆桑塔纳2000型轿车发动机为何无规律熄火

故障现象：一辆桑塔纳2000型轿车．发动机经常出现无规律熄火现象．但是每次熄火后过几分钟又能启动。     

企业募集资金投向与股东利益——基于中国上市公司的实证研究

本文以2003年度分别通过IPO上市、增发和配股三种方式来募集资金的91家上市公司作为研究样本,并引用一个较新的绩效评价指标-EVA指标来衡量公司的经营业绩,将改变募集资金投向的公司在2003年-2007年的经营业绩与未改变募集资金投向的公司在2003年-2007年的经营业绩来进行比较。通过两个子样本的EVA对比分析,得出企业改变募集资金投向是否有利与改善公司业绩,为股东创造财富。另外还把改变募集资金的公司按照其变更募集资金的类型分为五类,研究哪一类型的变更方式对于公司的经营业绩影响更为显著。     

The dynamic scheduling model of battlefield rush-repair tasks

During the war, equipment is constantly being damaged with limited battlefield rush-repair time and power. Therefore, some military problems are presented in this paper. In order to get more fighting time for damaged equipment to participate in operation again as much as possible, three problems should be considered properly. The first problem is how to dynamically choose the most suitable damaged equipment for each repair group. The second one is how to divide tasks between different groups. The third one is how to determine execution sequence in the same group. A mathematical model is established to solve the dynamic battlefield rushrepair task scheduling problem (DBRTSP) in wartime. A variant genetic algorithm is designed to dynamically track the change of the optimal solution. A scheduling example is solved through Matlab. Results show that the proposed model is not only scientific and reasonable, but also convenient and efficient.     

山区高速公路路侧风险等级评价方法研究

阐述了开展山区高速公路路侧事故安全评价研究对减少交通事故的重要意义。引入路侧事故风险指标做为中间变量,间接展示道路、交通、环境等条件与路侧事故风险的关系。随后基于模糊数学中的隶属函数构建了可定量评价山区高速公路路侧事故风险等级大小的方法。最后应用此方法对贵州省内4条山区高速公路路侧风险等级进行评价,验证了该方法的合理有效性。     

大吨位沉船打捞多体系统耦合水动力特性研究

双驳船抬吊法是大吨位沉船打捞中主要采用方法之一。两艘驳船、难船构成的系统具有尺度大、间距小等特点,波浪环境形成复杂水动力耦合效应,基于势流理论,增加人工阻尼修正其粘性影响,利用AQWA软件开展单驳船、两驳船约束其一、两驳船耦合三种状态多体系统水动力数值预报研究,重点分析不同状态下驳船运动响应及波浪载荷,探讨了驳船约束模式、浪向角及周期对驳船水动力影响规律,探明了浪向角与周期对驳船耦合水动力及运动响应不利干扰,对指导沉船打捞多体系统的空间布局与作业海况具有重要意义。