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   19848篇
  免费   823篇
各国政治   791篇
工人农民   709篇
世界政治   1463篇
外交国际关系   577篇
法律   12803篇
中国共产党   1篇
中国政治   120篇
政治理论   4081篇
综合类   126篇
  2020年   277篇
  2019年   361篇
  2018年   404篇
  2017年   487篇
  2016年   493篇
  2015年   384篇
  2014年   432篇
  2013年   1859篇
  2012年   419篇
  2011年   539篇
  2010年   474篇
  2009年   520篇
  2008年   527篇
  2007年   505篇
  2006年   508篇
  2005年   467篇
  2004年   457篇
  2003年   450篇
  2002年   450篇
  2001年   822篇
  2000年   714篇
  1999年   543篇
  1998年   325篇
  1997年   261篇
  1996年   250篇
  1995年   239篇
  1994年   270篇
  1993年   256篇
  1992年   401篇
  1991年   440篇
  1990年   419篇
  1989年   424篇
  1988年   400篇
  1987年   379篇
  1986年   457篇
  1985年   428篇
  1984年   369篇
  1983年   358篇
  1982年   247篇
  1981年   232篇
  1980年   191篇
  1979年   259篇
  1978年   151篇
  1977年   176篇
  1976年   153篇
  1975年   104篇
  1974年   156篇
  1973年   139篇
  1972年   133篇
  1971年   106篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
112.
The concentration of thyreoglobulin (tg) was determined for death caused by hanging, strangulation by ligature, and throttling. Cases of sudden death (traumatic aortic rupture, penetrating wounds of the heart) were used for comparison. The mean values in cases of hanging (149.9±202.3 ng/ml), strangulation by ligature (193.1±173.3), manual strangulation (561.6±173.9) are distinguishable from violent acute deaths (23.3±27.6) and living healthy individuals (17.3±16.1). By means of statistical comparisons, significant differences were found between throttling and strangulation by ligature and between throttling and hanging (adjusted P<0.001). In connection with examination of the bodies high tg values can be regarded as a vital reaction in obstructive asphyxia.  相似文献   
113.
A number of recent studies have explored the consequences ofinterracial peer effects on the academic and social performanceof minority students. This article contributes to that discussion,focusing, however, on perceptions rather than behaviors. Theanalysis suggests that exposure to white peers is associatedwith declining perceptions of racial justice among black andLatino high school students. While cautioning against causalinterpretations of this finding, the article suggests that theintegrationist aims of Brown v. Board of Education will notbe satisfied without more thoughtful and vigorous desegregationefforts.  相似文献   
114.
The manner in which agenda change occurs demonstrates how institutional arrangements influence agenda priorities in the Supreme Court and Courts of Appeals. A neo-institutional theoretic perspective is employed to examine the dynamics of agenda formation in these courts. The article finds that the Supreme Court's agenda choices influence the decisions of litigants, interest groups, and lawyers to appeal certain cases to the Courts of Appeals. While the Supreme Court's agenda primarily is influenced by internal factors, it is constrained by agenda changes in the appeals courts. Critically, it is shown that these federal appellate courts exist within an endogenous system with respect to agenda formation, as both courts respond to agenda changes made in the other over time.  相似文献   
115.
116.
117.
118.
119.
Deoxyribonucleic acid (DNA) typing of ribosomal ribonucleic acid (rRNA) genes was performed with a polymerase chain reaction (PCR) assay for species identification. A variable region of the 28S ribosomal RNA gene was amplified with primers complementary to flanking sequences phylogenetically well conserved. The products of twelve animal DNAs (human, Japanese monkey, dog, cattle, pig, cat, rabbit, mouse, rat, chicken, frog, and fish) were separated by polyacrylamide gel electrophoresis, each revealing a few bands ranging from 150 to 100 base pairs. The band patterns obtained from each DNA sample differed in number and size, which indicates the applicability of the method to species identification. Samples containing either as little as 1 pg of DNA or degraded DNA of 0.2 to 0.5 kb in length were able to give detectable bands. Postmortem human tissue DNAs were tested as an example. They showed a pattern identical to the human control one, which was distinct from those of the other animals examined.  相似文献   
120.
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