全文获取类型
收费全文 | 1252篇 |
免费 | 374篇 |
国内免费 | 43篇 |
专业分类
1669篇 |
出版年
2024年 | 3篇 |
2023年 | 9篇 |
2022年 | 15篇 |
2021年 | 63篇 |
2020年 | 31篇 |
2019年 | 11篇 |
2018年 | 14篇 |
2017年 | 45篇 |
2016年 | 13篇 |
2015年 | 43篇 |
2014年 | 49篇 |
2013年 | 73篇 |
2012年 | 63篇 |
2011年 | 63篇 |
2010年 | 87篇 |
2009年 | 103篇 |
2008年 | 93篇 |
2007年 | 107篇 |
2006年 | 50篇 |
2005年 | 76篇 |
2004年 | 31篇 |
2003年 | 22篇 |
2002年 | 19篇 |
2001年 | 32篇 |
2000年 | 23篇 |
1999年 | 109篇 |
1998年 | 59篇 |
1997年 | 68篇 |
1996年 | 42篇 |
1995年 | 41篇 |
1994年 | 36篇 |
1993年 | 37篇 |
1992年 | 35篇 |
1991年 | 26篇 |
1990年 | 26篇 |
1989年 | 11篇 |
1988年 | 14篇 |
1987年 | 10篇 |
1986年 | 7篇 |
1985年 | 5篇 |
1983年 | 3篇 |
1982年 | 2篇 |
排序方式: 共有1669条查询结果,搜索用时 15 毫秒
751.
Chung-Lun Li 《海军后勤学研究》1994,41(6):807-819
We consider the problem of scheduling a set of jobs on a single machine where the release time of a job is related to the amount of resource consumed. The objective is to minimize the total resource consumption with a control on the completion times of the jobs. Four different variants of the problem are studied: (i) minimization of the total resource consumption subject to a common deadline for all jobs, (ii) minimization of the total resource consumption subject to a constraint on the total completion time of the jobs, (iii) minimization of the weighted total resource consumption and maximum job completion time, and (iv) minimization of the weighted total resource consumption and the total job completion time. We compare the common resource consumption function with the function where the resource consumed is proportional to the processing time of the job. We show that these two different resource consumption functions can give rise to very different solution methods and different computational complexities for the problem. © 1994 John Wiley & Sons, Inc. 相似文献
752.
753.
754.
755.
756.
757.
758.
A single server is faced with a collection of jobs of varying duration and urgency. Each job has a random lifetime during which it is available for nonpreemptive service. Should a job's lifetime expire before its service begins then it is lost from the system unserved. The goal is to schedule the jobs for service to maximize the expected number served to completion. Two heuristics have been proposed in the literature. One (labeled πS) operates a static priority among the job classes and works well in a “no premature job loss” limit, whereas the second (πM) is a myopic heuristic which works well when lifetimes are short. Both can exhibit poor performance for problems at some distance from the regimes for which they were designed. We develop a robustly good heuristic by an approximative approach to the application of a policy improvement step to the asymptotically optimal heuristic πS, in which we use a fluid model to obtain an approximation for the value function of πS. The performance of the proposed heuristic is investigated in an extensive numerical study. © 2010 Wiley Periodicals, Inc. Naval Research Logistics 2010 相似文献
759.
讨论了受任意集中力、集中力偶和线性分布力作用的平面杆系结构内力分析技术.遍历单元的轴向和横向荷载特征点,生成该单元的“轴向荷载教组”和“横向荷载数组”,以此为基础,构造内力计算的“特征点截面法”和“特征点递推算法”,并进行了分析.分析结果表明:两种算法适合包含梯形分布的复杂荷载组合,是一种实用的平面杆系内力计算技术,可... 相似文献
760.