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   7419篇
  免费   177篇
各国政治   389篇
工人农民   201篇
世界政治   464篇
外交国际关系   290篇
法律   4659篇
中国共产党   1篇
中国政治   20篇
政治理论   1477篇
综合类   95篇
  2020年   71篇
  2019年   86篇
  2018年   129篇
  2017年   139篇
  2016年   160篇
  2015年   117篇
  2014年   134篇
  2013年   789篇
  2012年   208篇
  2011年   200篇
  2010年   159篇
  2009年   172篇
  2008年   198篇
  2007年   177篇
  2006年   188篇
  2005年   148篇
  2004年   150篇
  2003年   160篇
  2002年   165篇
  2001年   307篇
  2000年   275篇
  1999年   220篇
  1998年   83篇
  1997年   104篇
  1996年   79篇
  1995年   83篇
  1994年   91篇
  1993年   82篇
  1992年   158篇
  1991年   176篇
  1990年   155篇
  1989年   172篇
  1988年   149篇
  1987年   144篇
  1986年   168篇
  1985年   126篇
  1984年   125篇
  1983年   134篇
  1982年   79篇
  1981年   77篇
  1980年   57篇
  1979年   110篇
  1978年   63篇
  1977年   61篇
  1976年   57篇
  1975年   68篇
  1974年   81篇
  1973年   76篇
  1972年   67篇
  1971年   61篇
排序方式: 共有7596条查询结果,搜索用时 15 毫秒
951.
952.
953.
954.
Saliva and saliva-stained materials were examined as potential sources of deoxyribonucleic acid (DNA) for DNA analysis and identity testing. In this paper, the authors demonstrate that DNA was isolated and DNA banding patterns suitable for DNA typing were obtained from fresh saliva and various saliva-stained materials, such as envelopes, buccal swabs, gags, and cigarettes. Furthermore, DNA and DNA banding patterns were obtained from actual forensic evidentiary samples containing mixed saliva/semen stains. The DNA banding patterns obtained from saliva or saliva-stained material were indistinguishable from the patterns obtained from blood or hair from the same individual. Intact DNA was readily isolated and DNA banding patterns were obtained from saliva stored at -20 degrees C and dried saliva stains stored under varying conditions. We conclude that saliva and saliva-stained material can be good sources of DNA for analysis and for DNA typing in certain forensic settings.  相似文献   
955.
Blood stains on a knife were identified by DNA genotyposcopy. The statistical validation method has confirmed that the blood stains on material evidence belonged to the victim, the probability of random coincidence being less than 10(-11). The efficacy of using hypervariable locus-specific DNA probes and the possibility of detecting DNA impressions in blood stains stored for more than 3 months have been demonstrated.  相似文献   
956.
This paper tests empirically the Ramsey version of the public-interest theory of regulation by examining the pricing practices in the nuclear power industry, using a 1985 cross-sectional sample of 40 electric utilities. Other researchers have avoided this segment of the industry because of difficulties with nuclear fuel data, or perceived differences in the underlying production function. We show that regulators respond to political influences according to the Stigler-Peltzman version of regulation and that Ramsey pricing cannot be validated, at least for the nuclear segment of the electric power industry.  相似文献   
957.
958.
Study of dental root surfaces prompted the authors to add to the routine odontogram 28 more maxillary surfaces and 22 mandibular surfaces, this making a total of 210 diagnostic signs. Employment of amplified panoramic roentgenography permitted the authors to detect specific features of the dental cavity, root canals, periodontal fissure structure, the presence of caries and its complications, inflammatory and systemic involvement, injury to the jaws and teeth. Visual examination of dental status and application of panoramic roentgenography will help improve forensic medical personal identification.  相似文献   
959.
This paper reports the results of a forensic pathological study of 89 autopsy cases of Sudden Coronary Death (SCD). Of 89 cases, 63 (52 male, 11 female) were narrowed by 76-100% in cross-sectional area (XSA) of the coronary artery (CA) and 26 (22 male, 4 female), by 51-75%. Atherosclerotic plaques in the CA were serious and extensive, especially in the left anterior descending and often involved several branches of CA at the same time. Recent thrombosis was found in 18 cases, haemorrhage in plaques in 17 cases. Only 2 cases had visible acute myocardial infarction. Inflammatory cell infiltration was found in coronary plaques in 36 cases. Myocardial fibrosis or small scar formation was detected in 51 cases. It is suggested that although the incidence of coronary heart disease (CHD) is low in China, SCD is the commonest mode of Sudden Unexpected Death. The majority of SCD (52%) were middle aged males (30-49 years old). Most of the cases died suddenly during sleep without any clear precipitating factors. The characteristics of occurrence and pathological changes in the CA and myocardium and the pathological diagnosis of SCD are also analysed and discussed.  相似文献   
960.
This study used a modified version of the Conflict Tactics Scale to examine the prevalence of premarital aggression in a community sample of husbands and wives. The sample consisted of 625 couples participating in a longitudinal study of marital functioning and alcohol use. Consistent with past studies, the overall prevalence rate of husband-to-wife premarital aggression was 35%. Sociodemographic variables were associated with premarital aggression, with differences emerging primarily with regard to moderate aggression rather than mild aggression. Further, factors such as race, education, social class, cohabitation, and presence of children were independently associated with premarital aggression. This study is one of the first to examine premarital aggression in a large, heterogeneous sample of young husbands and wives at the same stage of relationship development. Future analyses will examine the prevalence, frequency, and continuity of husband and wife aggression over the first year of marriage.  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