首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   737篇
  免费   21篇
  2019年   16篇
  2018年   9篇
  2017年   25篇
  2016年   15篇
  2015年   17篇
  2014年   20篇
  2013年   173篇
  2012年   7篇
  2011年   10篇
  2010年   10篇
  2009年   14篇
  2008年   8篇
  2007年   6篇
  2006年   12篇
  2005年   15篇
  2004年   14篇
  2003年   7篇
  2002年   13篇
  2000年   9篇
  1999年   8篇
  1998年   13篇
  1997年   8篇
  1996年   11篇
  1995年   7篇
  1994年   18篇
  1993年   17篇
  1992年   13篇
  1991年   16篇
  1990年   10篇
  1989年   16篇
  1988年   17篇
  1987年   18篇
  1986年   17篇
  1985年   13篇
  1984年   8篇
  1983年   9篇
  1982年   7篇
  1981年   11篇
  1980年   6篇
  1979年   9篇
  1978年   12篇
  1976年   7篇
  1975年   8篇
  1974年   8篇
  1973年   8篇
  1972年   9篇
  1971年   5篇
  1970年   10篇
  1969年   6篇
  1967年   7篇
排序方式: 共有758条查询结果,搜索用时 31 毫秒
131.

The article takes the cases of Peru's Tupac Amaru Revolutionary Movement (MRTA) as the pont of departure to discuss how a insurgent political movement uses the Internet and World Wide Web (WWW). During the 1996–97 Japanese Embassy hostage incident in Lima, Peru, MRTA supporters in Japan, Europe and North America used online technology to relay the group's message to a global public. The resulting direct media access provided the MRTA with an unprecendented level of global publicity. Through referring to the ‘MRTA Solidarity Page’, the types of message transmitted, the forms of transmission (text, video, audio, e‐mail or other), and target publics (national, global, political elites, media), the article outlines the issues and theoretical challenges raised by electronic anti‐government information provision. The Internet and WWW do not alone constitute the threat to state power as some analysts suggest but does in some sense dramatically alter political communication. New media will probably co‐exist with other forms of political communication for some time.  相似文献   
132.
Building on prior work on optimal replacement of aging aircraft, this paper presents three methodologies to evaluate prospective aviation Service Life Extension Programs (SLEPs) and applies these methodologies to US Navy F/A-18E/F data. While considerable uncertainty remains as to the values of key parameters (e.g. the cost of F/A-18E/F SLEPs), the preponderance of the evidence available at this juncture favors undertaking SLEPs on F/A-18E/Fs rather than replacing them with new Joint Strike Fighters.  相似文献   
133.
A critical element in implementing a compensation scheme including nonmonetary incentives (NMIs) is recognizing that preferences vary widely across Service members. There are at least three sources of variability: across different population classes, across individuals within a population class, and across NMI packages for a particular individual. Surveys across different military communities, ranks, and years of Service show the difficulty of identifying any NMI that has significant value for even 50% of the active duty force. At the same time, approximately 80% of the surveyed Service members expressed a significant positive value for at least one NMI. Therefore, one-size-fits-all incentive packages will not be nearly as effective as more personalized incentive packages. The authors discuss variability in Service member NMI preferences and outline an approach to implementing personalized NMI packages in military compensation through a sealed-bid reverse auction, where Service members select individual NMIs from a “cafeteria-style” menu of options.  相似文献   
134.
135.
An alternating renewal process starts at time zero and visits states 1,2,…,r, 1,2, …,r 1,2, …,r, … in sucession. The time spent in state i during any cycle has cumulative distribution function Fi, and the sojourn times in each state are mutually independent, positive and nondegenerate random variables. In the fixed time interval [0,T], let Ui(T) denote the total amount of time spent in state i. In this note, a central limit theorem is proved for the random vector (Ui(T), 1 ≤ ir) (properly normed and centered) as T → ∞.  相似文献   
136.
137.
138.
139.
140.
A large population of independent identical units having finite mean lifetime T is observed. From the history A(y) of cumulative arrivals and the history B(y) of cumulative removals in the interval 0 ≦ y ≦ τ one must predict at time τ the desired T . Two lifetime predictors X(τ) and Y(τ) and related simple predictors obtained from A(y) and B(y) are shown to converge to T with a rate of convergence dependent on the structure of the failure rate function of the units. This dependence is studied theoretically and numerically.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号