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   11812篇
  免费   410篇
各国政治   500篇
工人农民   393篇
世界政治   994篇
外交国际关系   496篇
法律   6910篇
中国政治   69篇
政治理论   2780篇
综合类   80篇
  2021年   59篇
  2020年   168篇
  2019年   188篇
  2018年   250篇
  2017年   287篇
  2016年   313篇
  2015年   223篇
  2014年   254篇
  2013年   1370篇
  2012年   299篇
  2011年   295篇
  2010年   293篇
  2009年   292篇
  2008年   313篇
  2007年   355篇
  2006年   363篇
  2005年   325篇
  2004年   319篇
  2003年   330篇
  2002年   289篇
  2001年   397篇
  2000年   406篇
  1999年   304篇
  1998年   196篇
  1997年   154篇
  1996年   123篇
  1995年   148篇
  1994年   148篇
  1993年   131篇
  1992年   216篇
  1991年   210篇
  1990年   195篇
  1989年   225篇
  1988年   203篇
  1987年   225篇
  1986年   198篇
  1985年   230篇
  1984年   183篇
  1983年   189篇
  1982年   150篇
  1981年   145篇
  1980年   107篇
  1979年   144篇
  1978年   110篇
  1977年   99篇
  1976年   80篇
  1975年   69篇
  1974年   82篇
  1973年   82篇
  1970年   59篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
52.
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   
53.
54.
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   
55.
A 22-year-old Korean soldier, who had received blows to the neck and epigastrium from an officer 10 h earlier, suddenly died after massive hematemesis. He had been in relatively good health except for episodes of blood-tinged vomiting approximately 5 and 7 months prior to this event. Postmortem examination revealed angiodysplasia involving the gastroesophageal junction, and the stomach was distended with blood. No abnormal findings were present around the whole viscera, and the duodenum was free of blood. The pathologic significance of upper gastrointestinal angiodysplasia as a potential source of bleeding and a chronologic correlation between the trauma and bleeding are discussed.  相似文献   
56.
European Journal of Law and Economics - In this article I try to find answers for three questions: Which functions are exercised by the Court of Audit in the Netherlands, and what kinds of...  相似文献   
57.
The primary aim of this paper is to review the literature on preadolescent friendships in order to examine the relationship between preadolescent friendships and social support in adulthood. Social supports are important to health, both directly and as a stress buffer. Few studies, however, have specifically examined adult social supports from the perspective of their developmental precursors and critical developmental periods. Some data indicate that the preadolescent period may be of particular importance to the development of adult social skills and ties. Observational and empirical studies of preadolescent peer relationships, and in particular best friendships, suggest unique and critical contributions to adult social relatedness. Present research is suggestive but is insufficient to validate preadolescence as a critical period in adult social relatedness. Our review has implications for better understanding the mechanisms by which preadolescent friendships effect adult social support—an important mediator of the effects of stress on health. Further longitudinal study is needed.Received Ph.D. from University of Maryland. Research interests are social supports and psychological responses to trauma and disaster.Received M.D. from Yale University. Research interests are social supports and traumatic stress.  相似文献   
58.
59.
60.
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