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   9493篇
  免费   306篇
各国政治   626篇
工人农民   365篇
世界政治   746篇
外交国际关系   386篇
法律   5393篇
中国共产党   2篇
中国政治   140篇
政治理论   2038篇
综合类   103篇
  2020年   124篇
  2019年   143篇
  2018年   205篇
  2017年   230篇
  2016年   229篇
  2015年   199篇
  2014年   205篇
  2013年   1145篇
  2012年   240篇
  2011年   325篇
  2010年   236篇
  2009年   252篇
  2008年   256篇
  2007年   237篇
  2006年   236篇
  2005年   208篇
  2004年   229篇
  2003年   245篇
  2002年   180篇
  2001年   369篇
  2000年   339篇
  1999年   309篇
  1998年   157篇
  1997年   117篇
  1996年   118篇
  1995年   110篇
  1994年   113篇
  1993年   112篇
  1992年   167篇
  1991年   164篇
  1990年   151篇
  1989年   142篇
  1988年   165篇
  1987年   165篇
  1986年   169篇
  1985年   151篇
  1984年   151篇
  1983年   161篇
  1982年   99篇
  1981年   70篇
  1980年   82篇
  1979年   103篇
  1978年   84篇
  1977年   68篇
  1976年   70篇
  1975年   63篇
  1973年   55篇
  1972年   56篇
  1971年   61篇
  1969年   58篇
排序方式: 共有9799条查询结果,搜索用时 15 毫秒
721.
722.
Guardian angels     
Gorman C 《Time》2001,157(12):75
  相似文献   
723.
We report here the results of mtDNA analysis of remains exhumed in July, 1995 from Mt. Olivet Cemetery in Kearney, Nebraska, that are thought to be those of Jesse James. The remains were poorly preserved, presumably due to wet and slightly acidic soil conditions, and insufficient DNA for analysis was obtained from two bone samples. However, two of four teeth, and two hairs recovered in 1978 from the original burial site on the James Farm, did yield reproducible mtDNA sequences. These mtDNA sequences from the teeth and hairs were all identical, suggesting that they came from the same individual; furthermore, this mtDNA sequence was identical to mtDNA sequences determined from blood samples from two maternal relatives of Jesse James. Therefore, either the remains are indeed those of Jesse James, or they are from an unrelated individual who, by chance, happens to have the same mtDNA sequence. To assess the probability that an unrelated individual would have the same sequence, we searched the forensic mtDNA database, and found that this sequence does not appear among the 2426 mtDNA sequences therein. Hence, the mtDNA analysis supports the identification of the exhumed remains from Mt. Olivet Cemetery as those of Jesse James.  相似文献   
724.
725.
726.
The authors are privileged to have been provided with correspondence about a dispute over the ongoing storage of genetic material (as Guthrie Cards) in Victoria. The correspondence details confusion over the roles of government and the private sector service provider in accounting for the storage, use and destruction of these stored genetic materials collected as part of a government public health program. The purpose in publishing this account is to highlight the present inadequacies in current practices and the ongoing potential for a crisis in the management of collected genetic materials through a lack of appropriate regulation, transparency and accountability. The article suggests measures to remedy some of the existing inadequacies in contractual arrangements and recommends that the government retain ownership and control of both the genetic materials and the derived information to ensure some accountability in the present legal environment.  相似文献   
727.
728.
729.
730.
Methods of facial approximation have successfully aided the identification of deceased individuals. Successes may be due to either accurate facial approximation techniques or chance. This study aims to determine if any of 16 facial approximations, built using standard techniques, are sufficiently accurate to produce correct identifications of target individuals above chance. Four skulls were approximated using four commonly used methods of facial approximation. The resulting 16 facial approximations were judged by 37 assessors of varying ages. Assessors attempted to identify the target individual of each facial approximation from a face pool of ten photographed faces. Only one facial approximation resulted in true positive identification rates above chance at statistically significant levels. It is concluded that it is rare for facial approximations to be sufficiently accurate to allow identification of a target individual above chance. Since 403 incorrect identifications were made out of 592 identification scenarios, facial approximation should be considered to be a highly inaccurate and unreliable forensic technique. These results suggest that facial approximations are not very useful in excluding individuals to whom skeletal remains may not belong. Evidence from this experiment supports suggestions by others that facial approximation should be used in forensic science when all other methods of identification have failed and only to provide tentative identification.  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