全文获取类型
收费全文 | 713篇 |
免费 | 1篇 |
专业分类
714篇 |
出版年
2021年 | 8篇 |
2020年 | 6篇 |
2019年 | 7篇 |
2017年 | 15篇 |
2016年 | 12篇 |
2015年 | 11篇 |
2014年 | 12篇 |
2013年 | 118篇 |
2012年 | 25篇 |
2011年 | 29篇 |
2010年 | 23篇 |
2009年 | 15篇 |
2008年 | 30篇 |
2007年 | 16篇 |
2006年 | 15篇 |
2005年 | 9篇 |
2004年 | 6篇 |
2002年 | 5篇 |
1999年 | 5篇 |
1998年 | 6篇 |
1997年 | 6篇 |
1996年 | 5篇 |
1995年 | 10篇 |
1994年 | 12篇 |
1993年 | 13篇 |
1992年 | 10篇 |
1991年 | 10篇 |
1990年 | 7篇 |
1989年 | 16篇 |
1988年 | 9篇 |
1987年 | 15篇 |
1986年 | 18篇 |
1985年 | 12篇 |
1983年 | 9篇 |
1982年 | 12篇 |
1981年 | 9篇 |
1980年 | 13篇 |
1979年 | 14篇 |
1978年 | 7篇 |
1977年 | 11篇 |
1976年 | 9篇 |
1975年 | 11篇 |
1974年 | 7篇 |
1973年 | 7篇 |
1972年 | 18篇 |
1971年 | 13篇 |
1970年 | 5篇 |
1969年 | 14篇 |
1968年 | 11篇 |
1966年 | 6篇 |
排序方式: 共有714条查询结果,搜索用时 15 毫秒
91.
对钢丝绳联轴器进行了动刚度性能实验 ,在此基础上建立了数学模型 ,并进行了参数辨识 ,指出钢丝绳联轴器具有强非线性 ,对减小轴系扭转振动具有良好的效果 相似文献
92.
93.
In sensitivity testing for the Department of Defense, the high cost of experimental units necessitates the use of small sample sizes and accentuates the importance of design. This article compares five data collection-estimation procedures. Four of these are modifications of the Robbins-Monro method, and the other is the Langlie. The simulation study is designed as a factorial experiment with response function, sample size, initial design point, gate width, and noise as factors. The estimated V50 and its MSE are the responses compared to assess the small sample behavior of each method. Although there is no single clear-cut winner, the Delayed Robbins-Monro (DRM) with maximum likelihood estimation and the Estimated Quantal Response Curve (Wu [21]) are shown to perform well over a broad variety of conditions. 相似文献
94.
Rendezvous search finds the strategies that players should use in order to find one another when they are separated in a region. Previous papers have concentrated on the case where there are two players searching for one another. This paper looks at the problem when there are more than two players and concentrates on what they should do if some but not all of them meet together. It looks at two strategies—the stick together one and the split up and meet again one. This paper shows that the former is optimal among the class of strategies which require no memory and are stationary, and it gives a method of calculating the expected rendezvous time under it. However, simulation results comparing both strategies suggest that in most situations the split up and meet again strategy which requires some memory leads to faster expected rendezvous times. © 2001 John Wiley & Sons, Inc. Naval Research Logistics 48:710–721, 2001 相似文献
95.
96.
97.
Henry U. Ufomba 《Defense & Security Analysis》2012,28(4):360-367
Apart from North Korea, no state's nuclear program in the twenty-first century has raised more concern to international security than Iran's. While Iran insists that its nuclear program is strictly for civilian purpose in line with Article IV of non-proliferation treaty, the USA and its allies insist that Iran has military intentions and called for sanctions. The failure of sanctions to deter Iran from its nuclear agenda had made many scholars and policy-makers call for a preemptive attack on Iranian nuclear facilities. Situated within this debate, this paper positions itself as an antagonist to the preemptive airstrike option and argues that involving India in a possible nuclear “iron curtain” against Iran – a move known as technical isolation – remains the best option to the current nuclear crises. 相似文献
98.
计算了一类二次Hamilton微分系统的一阶Mel’nikov函数,通过此方法对该系统在三次多项式扰动下分岔的极限环个数进行了估计。 相似文献
99.
空投设备气囊缓冲系统的缓冲特性分析与匹配方法 总被引:1,自引:0,他引:1
采用解析分析法,根据排气口流量方程和载荷运动方程建立了无量纲的空投设备气囊缓冲过程数学模型,并根据此模型构造了气囊的匹配设计图。讨论了排气口面积、气囊高度、着陆初速度、载荷质量、气囊底面积及排气口开启压力等参数对气囊缓冲性能的影响,提出了空投设备气囊缓冲系统的参数匹配设计方法,为空投设备气囊缓冲系统的匹配设计提供了技术支持。 相似文献
100.