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   19779篇
  免费   345篇
各国政治   670篇
工人农民   1572篇
世界政治   980篇
外交国际关系   627篇
法律   11744篇
中国政治   79篇
政治理论   4356篇
综合类   96篇
  2020年   120篇
  2019年   180篇
  2018年   1456篇
  2017年   1407篇
  2016年   1247篇
  2015年   239篇
  2014年   222篇
  2013年   1149篇
  2012年   434篇
  2011年   1180篇
  2010年   1212篇
  2009年   857篇
  2008年   1023篇
  2007年   981篇
  2006年   321篇
  2005年   336篇
  2004年   438篇
  2003年   431篇
  2002年   311篇
  2001年   449篇
  2000年   403篇
  1999年   315篇
  1998年   181篇
  1997年   157篇
  1996年   176篇
  1995年   184篇
  1994年   173篇
  1993年   152篇
  1992年   258篇
  1991年   273篇
  1990年   254篇
  1989年   263篇
  1988年   244篇
  1987年   238篇
  1986年   273篇
  1985年   275篇
  1984年   244篇
  1983年   230篇
  1982年   169篇
  1981年   136篇
  1980年   124篇
  1979年   170篇
  1978年   100篇
  1977年   128篇
  1976年   102篇
  1975年   76篇
  1974年   94篇
  1973年   89篇
  1972年   78篇
  1971年   72篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
The polymerase chain reaction (PCR) method of specific gene amplification was used in casework to synthesize millions of copies of the polymorphic second exon of the human leukocyte antigen (HLA)-DQ alpha (or DQA1) locus from a variety of evidence samples. The HLA-DQ alpha allelic variants in the amplified deoxyribonucleic acid (DNA) were determined in a rapid non-radioactive test by hybridization to sequence-specific oligonucleotide probes in both the dot-blot and reverse dot-blot formats. This genetic typing system has been subjected to blind proficiency testing; the performance of this test in the analysis of experimentally mixed samples was also evaluated. As of August 1990, over 250 cases have been tested and more than 2000 individual evidence (bloodstains, semen stains, individual hairs, bone fragments, and tissue sections) and reference samples have been analyzed. The first 198 of these cases are summarized in this paper; in 65% of the cases with conclusive results a suspect was included, and in 35%, all suspects were excluded. Individual cases as well as some of the general issues relating to forensic science analysis and this genetic typing system are discussed. The high rate of exclusion reported here combined with the ability of PCR to type old evidence samples suggests the relevance of this genetic test for postconviction review; two cases in which the convicted suspect was excluded are discussed.  相似文献   
92.
An improved method has been developed for the reliable classification of different C1R genetic variant forms from human serum or plasma. The method combines the use of neuraminidase-digested samples followed by monodimensional isoelectric focusing in the pH range 5 to 8 followed by immunoblotting. The method yields a simple pattern, with one major band in homozygote and two major bands in heterozygote cases.  相似文献   
93.
Fabella  R. V. 《Public Choice》1996,89(3-4):325-337
Public Choice - We consider an economy where the rent value depends indirectly on value-adding investment of agents (thus indirectly endogenous) and the win-probability is a function of rent...  相似文献   
94.
95.
96.
We develop a model of the peace dividend and use it to predict the fiscal consequences of a reduction in the demand for military spending. The model is based on the assumption that the political process responds to political demands and costs in a way that maximizes net political benefits. The predictions of our model on how a peace dividend will be allocated over nonmilitary spending, tax relief, and deficit reduction is tested against the experience of eight major wars in United States history.  相似文献   
97.
A method ist described to determine the CO-content in the tissue of muscles. The prepared tissue is pulverized in a swinging mill at the temperature of liquid nitrogen. Parts of the powder are weighed into headspace vessels. Carbon monoxide ist ejected by a formerly described method and measured gaschromatographically. The Fe-content is determined after an acid disintegration by AAS. Acute intoxications lead to higher CO-contents in heart than in periphere muscles. Chronic exposure to carbon monoxide does not produce these differences.  相似文献   
98.
99.
We tested competing hypotheses derived from Gottfredson and Hirschis (1990) general theory and Moffitt's (1993a) developmental theory of antisocial behavior. The developmental theory argues that different factors give rise to antisocial behavior at different points in the life course. In contrast, the general theory maintains that the factor underlying antisocial behavior (i.e., criminal propensity) is the same at all ages. To test these competing predictions, we used longitudinal data spanning from age 5 to age 18 for the male subjects in the Dunedin Multidisciplinary Health and Development Study. Using reports from three sources (parents, teachers, and the boys themselves), we estimated second-order confirmatory factor models of antisocial behavior. These models provided consistent support for the developmental theory, showing that separate latent factors underlie childhood and adolescent antisocial behavior. Moreover, we found that these childhood and adolescent factors related in ways predicted by Moffitt's developmental theory to four correlates of antisocial behavior: Childhood antisocial behavior was related more strongly than adolescent antisocial behavior to low verbal ability, by per activity, and negative/impulsive personality, whereas adolescent antisocial behavior was related more strongly than childhood antisocial behavior to peer delinquency. The two underlying latent factors also showed the predicted differential relations to later criminal convictions: Childhood antisocial behavior was significantly more strongly associated with convictions for violence, while adolescent antisocial behavior was significantly more strongly associated with convictions for nonviolent offenses.  相似文献   
100.
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