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   7159篇
  免费   460篇
各国政治   339篇
工人农民   227篇
世界政治   476篇
外交国际关系   233篇
法律   5022篇
中国政治   34篇
政治理论   1252篇
综合类   36篇
  2020年   157篇
  2019年   167篇
  2018年   179篇
  2017年   207篇
  2016年   211篇
  2015年   196篇
  2014年   183篇
  2013年   743篇
  2012年   155篇
  2011年   171篇
  2010年   205篇
  2009年   222篇
  2008年   162篇
  2007年   158篇
  2006年   170篇
  2005年   160篇
  2004年   178篇
  2003年   158篇
  2002年   138篇
  2001年   309篇
  2000年   252篇
  1999年   228篇
  1998年   100篇
  1997年   66篇
  1996年   69篇
  1995年   80篇
  1994年   87篇
  1993年   87篇
  1992年   152篇
  1991年   156篇
  1990年   148篇
  1989年   156篇
  1988年   122篇
  1987年   137篇
  1986年   124篇
  1985年   133篇
  1984年   101篇
  1983年   116篇
  1982年   82篇
  1981年   78篇
  1980年   55篇
  1979年   108篇
  1978年   69篇
  1977年   58篇
  1976年   50篇
  1975年   47篇
  1974年   55篇
  1973年   55篇
  1972年   44篇
  1968年   40篇
排序方式: 共有7619条查询结果,搜索用时 15 毫秒
991.
The Electric Power Research Institute (EPRI) is a consortium of utility companies whose existence depends on member perceptions that valuable technologies and information have been developed and transferred. This paper outlines eight issues that EPRI, after 17 years of operation had determined to be critical in transferring technology: [1] establishing a perception of value received, [2] creating a sense of full partnership, [3] balancing the R&D portfolio with projects for different members, [4] packaging results for easy understanding and use, [5] reducing information overload by using targeted media, [6] assuring that members have the needed infrastructure to receive and process transfer, [7] integrating EPRI's R&D program with those of the members, and [8] monitoring impact to be sure that value is being received.  相似文献   
992.
Although the current resurgence of ecological deterrence research has addressed many of the methodological and theoretical problems of earlier studies, the question concerning the appropriate level of aggregation for such models has not been resolved. In this paper, we argue that there is strong evidence in the criminological literature that the neighborhood is the most meaningful level of aggregation for such studies. However, in an analysis of robbery incidents and arrests over 100 weeks in five Oklahoma City neighborhoods we did not find any significant support for the deterrent effect of arrests on subsequent illegal behavior. We propose that the lack of such a relationship reflects periods of short-term equilibrium in the local community, during which the levels of crime and arrests are relatively stabilized.  相似文献   
993.
994.
Fatal nitrous oxide poisoning usually occurs accidentally during the administration of general anesthesia. It seldom occurs during autoerotic behavior or in acute drug abuse. We report an unusual case of a health professional who committed suicide by inhaling nitrous oxide.  相似文献   
995.
On the basis of the data presented above the following conclusions may be drawn. 1. The molecular ion peaks of most of the compounds examined are relatively weak but usually easily discernible to permit molecular weight determination. 2. The mass spectra of benzilate esters exhibit a relatively intense peak at m/e 183, and monitoring of this ion can serve as a means for preliminary screening for the presence of this type of a system. 3. Related esters exhibit a similar type of fragmentation resulting in a fragment ion analogous to m/e 183 but shifted by the appropriate number of mass units according to the substituents present. 4. Cleavage of the piperidine ring-ester oxygen bond in 3 and 4-substituted isomers is followed by selective losses of hydrogen radicals to produce ions of type e, f, and g as indicated above. It is significant that in a related piperidine ring system (methylphenidate) substituted in the 2 position, the same type of cleavage results in no further hydrogen losses [16] because of charge stabilization from the ring nitrogen (ion j, Fig. 17) [17]. In other words, the tendency to form a conjugated ion following initial bond cleavage can serve as a means for identifying the position of substitution on the ring and for distinguishing positional isomers.  相似文献   
996.
997.
Mental health professionals have focused attention on the psychiatric sequelae of criminal victimization. This article compares the experience of white collar and violent crime victims on several parameters including statistical risk of victimization and psychiatric outcome after victimization. Emphasis is given to data obtained from interviewing 77 victims of a fraudulent financial scheme.  相似文献   
998.
999.
1000.
This paper examines factors associated with the cesarean birth rate, including medical condition and method of payment, in the largest maternity hospital of Fortaleza, Brazil. Data were collected on 5996 women who delivered at the Maternidade Escola Assis Chateaubriand from October 1980 to July 1981. All women were classified according to how they paid for their care: private (financed at least part of their care with own funds), insured (federal or state), or indigent. Private patients were found to be far more likely than patients in the other two groups to have cesarean deliveries, due primarily to the high percentage of private patients recorded as having prolonged or obstructed labor, combined with a high rate of prior cesarean sections. From this data, it appears likely that financial incentives did play a role in physician decisions on whether to perform cesarean deliveries.  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