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   31271篇
  免费   1702篇
各国政治   1351篇
工人农民   1283篇
世界政治   2331篇
外交国际关系   1017篇
法律   20614篇
中国共产党   3篇
中国政治   213篇
政治理论   5943篇
综合类   218篇
  2020年   570篇
  2019年   655篇
  2018年   844篇
  2017年   880篇
  2016年   949篇
  2015年   773篇
  2014年   819篇
  2013年   3262篇
  2012年   792篇
  2011年   903篇
  2010年   929篇
  2009年   949篇
  2008年   859篇
  2007年   834篇
  2006年   936篇
  2005年   754篇
  2004年   751篇
  2003年   674篇
  2002年   700篇
  2001年   1120篇
  2000年   977篇
  1999年   806篇
  1998年   450篇
  1997年   365篇
  1996年   339篇
  1995年   372篇
  1994年   362篇
  1993年   355篇
  1992年   564篇
  1991年   611篇
  1990年   567篇
  1989年   573篇
  1988年   569篇
  1987年   526篇
  1986年   570篇
  1985年   603篇
  1984年   533篇
  1983年   486篇
  1982年   375篇
  1981年   347篇
  1980年   324篇
  1979年   410篇
  1978年   250篇
  1977年   203篇
  1976年   189篇
  1975年   209篇
  1974年   244篇
  1973年   199篇
  1972年   169篇
  1971年   150篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
22.
23.
24.
The present study measured the existence of traumatic stress symptomatology as reported by certified law enforcement officers within the State of Delaware. A questionnaire was devised which documented age, sex, race, education, years of service, marital status, children, rank, position, and shift work. The questionnaire was divided into parts which assessed the exposure and the frequency of specific traumatic incidents experienced in the line of duty, and the frequency of experienced traumatic symptomatology criteria: re-experiencing, numbing, and arousal.  相似文献   
25.
26.
27.
This study aimed to expand the scope of previous research by assessing the effectiveness of soot-removal techniques on glass from petrol-bomb debris using methods of 1% and 2% sodium hydroxide (NaOH) solutions, ultrasonic bath and vacuum suction. Of particular interest were the 1% and 2% NaOH solutions applied to the soot-covered surfaces. Petrol bombs containing petrol or a 50:50 mix of petrol and motor oil were exploded and the debris was collected for analysis. Favourable results were found to varying degrees using each of the soot-removal methods with the 1% and 2% NaOH wash solutions, being the most useful. The 2% NaOH solution also proved successful as a soak to loosen and remove heavy contamination of soot and accelerants without damaging the finger mark beneath. This study also found that recovery of finger marks in blood from beneath soot using the 2% NaOH solution was possible. Finger marks were also applied to glass bottles with plastic adhesive labels, and providing the fire damage is not too great marks were also retrievable. Results from this study lead to the conclusion that the NaOH wash solution is ideally suited for soot removal to reveal latent and blood-contaminated marks both within the laboratory and at crime scenes.  相似文献   
28.
The lungs of 79 children who had died between the ages of 1 week and 2 years old were histologically examined. 59 of these children could be categorized as cases of Sudden Infant Death because of the history and postmortem findings. In the remaining 20 cases a definite cause of death could be established. This is the same collective on which the histological investigations of the lymphatic tissue has been carried out. Morphological changes which are typical for a virus pneumonia were found in a substantially higher frequency in the cases of Sudden Infant Death than in the control cases. The validity of these findings and their possible significance for the cause of death are discussed.  相似文献   
29.
Restriction fragment length polymorphism (RFLP) analysis for the purpose of individualization is now being used in casework in the People's Republic of China. This report describes the use of the multilocus minisatellite probe 33.15 to solve three cases, including two homicides and a rape. In the third case, fetal tissue was analyzed to prove that the alleged rapist was, in fact, the father. In each case, analysis of deoxyribonucleic acid (DNA) resulted in a positive match. The probability of chance association of the DNA fingerprint was calculated as 5.6 x 10(-12), which is similar to the figures reported in the literature.  相似文献   
30.
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