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   15453篇
  免费   417篇
各国政治   578篇
工人农民   617篇
世界政治   1069篇
外交国际关系   505篇
法律   9705篇
中国政治   96篇
政治理论   3183篇
综合类   117篇
  2020年   172篇
  2019年   254篇
  2018年   308篇
  2017年   329篇
  2016年   342篇
  2015年   241篇
  2014年   286篇
  2013年   1475篇
  2012年   333篇
  2011年   395篇
  2010年   309篇
  2009年   383篇
  2008年   395篇
  2007年   393篇
  2006年   398篇
  2005年   330篇
  2004年   340篇
  2003年   353篇
  2002年   332篇
  2001年   605篇
  2000年   553篇
  1999年   433篇
  1998年   221篇
  1997年   181篇
  1996年   187篇
  1995年   184篇
  1994年   194篇
  1993年   188篇
  1992年   346篇
  1991年   342篇
  1990年   360篇
  1989年   364篇
  1988年   356篇
  1987年   345篇
  1986年   349篇
  1985年   354篇
  1984年   310篇
  1983年   288篇
  1982年   204篇
  1981年   172篇
  1980年   155篇
  1979年   200篇
  1978年   126篇
  1977年   135篇
  1976年   124篇
  1975年   97篇
  1974年   122篇
  1973年   109篇
  1972年   102篇
  1971年   90篇
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
91.
92.
93.
94.
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   
95.
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   
96.
97.
98.
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   
99.
This paper describes a collaborative exercise intended to demonstrate whether uniformity of DNA profile results could be achieved between different European laboratories. It was shown that this goal can be obtained provided that a common protocol is followed (specifically the use of a common electrophoretic buffer as being the most important parameter). Generally, lower molecular weight loci (with lower molecular weight fragments) such as YNH24 perform better than higher molecular weight loci such as MS43a. The results of the exercise are discussed in relation to the objectives of the European DNA profiling group (EDNAP).  相似文献   
100.
The authors examine the characteristics of threatening and otherwise inappropriate communications sent to members of the U.S. Congress by a sample of 86 subjects, 20 of whom threatened assassination. We quote excerpts from these letters and provide quantitative data on such variables as the volume, duration, form, and appearance of such communications; the enclosures; the subjects' perceived relationships to the recipients; the thematic content of the communications; and the messages and threats communicated. Comparisons between 43 subjects who pursued encounters with members of Congress and 43 who did not revealed 17 factors associated with such pursuit. In this population, threateners were significantly less likely to pursue an encounter than inappropriate letter writers who did not threaten, regardless of the type of threat or the harm threatened. Inappropriate letters to members of Congress are compared with those directed to Hollywood celebrities. Mentally disordered persons writing to public figures often mention and sometimes threaten public figures other than those to whom the letters are addressed, which raises important issues regarding notification of endangered third parties and the sharing of information among protective agencies.  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