全文获取类型
收费全文 | 214篇 |
免费 | 74篇 |
国内免费 | 7篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 5篇 |
2020年 | 16篇 |
2019年 | 5篇 |
2018年 | 5篇 |
2017年 | 17篇 |
2016年 | 9篇 |
2015年 | 9篇 |
2014年 | 18篇 |
2013年 | 13篇 |
2012年 | 17篇 |
2011年 | 17篇 |
2010年 | 12篇 |
2009年 | 11篇 |
2008年 | 14篇 |
2007年 | 13篇 |
2006年 | 11篇 |
2005年 | 14篇 |
2004年 | 13篇 |
2003年 | 11篇 |
2002年 | 8篇 |
2001年 | 9篇 |
2000年 | 5篇 |
1999年 | 6篇 |
1998年 | 13篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 2篇 |
排序方式: 共有295条查询结果,搜索用时 15 毫秒
191.
This article deals with evaluating the frequency response of functionally graded carbon nanotube rein-forced magneto-electro-elastic (FG-CNTMEE) plates subjected to open and closed electro-magnetic cir-cuit conditions. In this regard finite element formulation has been derived. The plate kinematics adjudged via higher order shear deformation theory (HSDT) is considered for evaluation. The equations of motion are obtained with the help of Hamilton's principle and solved using condensation technique. It is found that the convergence and accuracy of the present FE formulation is very good to address the vibration problem of FG-CNTMEE plate. For the first time, frequency response analysis of FG-CNTMEE plates considering the effect of various circuit conditions associated with parameters such as CNT dis-tributions, volume fraction, skew angle, aspect ratio, length-to-thickness ratio and coupling fields has been carried out. The results of this article can serve as benchmark for future development and analysis of smart structures. 相似文献
192.
刘东海 《中国人民武装警察部队学院学报》2001,17(1):46-52
假定(X1,Y1),(X2,Y2),…,(Xn,Yn)是取自二维随机向量(X,Y)的独立同分布样本.记X(1)≤X(2)≤…≤X(n)是X1,X2,…,Xn产生的次序统计量,Y[1],Y[2],…,Y[n]是诱导的次序统计量.讨论广义L-统计量Tn=n-1 n∑i=1 J(i/n+1)Y[i]的极限分布,式中J(x)是由实际问题的需要而选取的权函数.在较弱的条件下,证明了Tn的渐近正态性,同时给出了Tn的期望和方差的渐近公式. 相似文献
193.
低轨单星对自由段弹道的估计是天基预警系统需解决的关键技术之一.建立了低轨预警卫星对自由段弹道的观测模型,针对极大似然估计批处理算法的大运算量问题,给出了一种多项式逼近算法,由观测数据的逼近多项式在一些特定采样点的值形成伪观测数据,以伪观测数据代替原观测数据进行弹道估计.仿真表明,精度与极大似然估计相当,运算量显著降低. 相似文献
194.
195.
196.
Ikuo Arizono Akihiro Kanagawa Hiroshi Ohta Kyouko Watakabe Kouji Tateishi 《海军后勤学研究》1997,44(6):591-603
Taguchi has presented an approach to quality improvement in which reduction of deviation from the target value is the guiding principle. In this approach any measured value x of a product characteristic X brings a loss to consumer in general, where the loss is expressed as a quadratic form with respect to the difference between the measured value x and the target value T of a product characteristic. Then, it is natural to reject the lot which may bring a large loss to consumer. This concept induces us to construct new variable sampling plans based on the Taguchi's loss criterion. In this article, a design procedure of the sampling plans for assuring the loss in the Taguchi's method is proposed. Some numerical results based on the proposed design procedures are illustrated. © 1997 John Wiley & Sons, Inc. Naval Research Logistics 44: 591–603 (1997) 相似文献
197.
This paper considers a two-agent scheduling problem with linear resource-dependent processing times, in which each agent has a set of jobs that compete with that of the other agent for the use of a common processing machine, and each agent aims to minimize the weighted number of its tardy jobs. To meet the due date requirements of the jobs of the two agents, additional amounts of a common resource, which may be in discrete or continuous quantities, can be allocated to the processing of the jobs to compress their processing durations. The actual processing time of a job is a linear function of the amount of the resource allocated to it. The objective is to determine the optimal job sequence and resource allocation strategy so as to minimize the weighted number of tardy jobs of one agent, while keeping the weighted number of tardy jobs of the other agent, and the total resource consumption cost within their respective predetermined limits. It is shown that the problem is -hard in the ordinary sense, and there does not exist a polynomial-time approximation algorithm with performance ratio unless ; however it admits a relaxed fully polynomial time approximation scheme. A proximal bundle algorithm based on Lagrangian relaxation is also presented to solve the problem approximately. To speed up convergence and produce sharp bounds, enhancement strategies including the design of a Tabu search algorithm and integration of a Lagrangian recovery heuristic into the algorithm are devised. Extensive numerical studies are conducted to assess the effectiveness and efficiency of the proposed algorithms. 相似文献
198.
199.
运用饱和信息维的增减技术对信息获取子空间进行结构上的剖分,将饱和信息维的"值"的获取分解为"白"与"灰"两部分,用饱和信息维列作为因子列来构造灰色关联空间,用关联序来描述信息之间的相关联程度,得到信息资源聚焦的一种新的数学模型。 相似文献
200.
We consider the problem of scheduling n independent and simultaneously available jobs without preemption on a single machine, where the machine has a fixed maintenance activity. The objective is to find the optimal job sequence to minimize the total amount of late work, where the late work of a job is the amount of processing of the job that is performed after its due date. We first discuss the approximability of the problem. We then develop two pseudo‐polynomial dynamic programming algorithms and a fully polynomial‐time approximation scheme for the problem. Finally, we conduct extensive numerical studies to evaluate the performance of the proposed algorithms. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 63: 172–183, 2016 相似文献