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   19679篇
  免费   1350篇
各国政治   830篇
工人农民   751篇
世界政治   1318篇
外交国际关系   539篇
法律   13805篇
中国共产党   4篇
中国政治   140篇
政治理论   3487篇
综合类   155篇
  2020年   419篇
  2019年   448篇
  2018年   562篇
  2017年   633篇
  2016年   650篇
  2015年   546篇
  2014年   537篇
  2013年   2054篇
  2012年   484篇
  2011年   570篇
  2010年   694篇
  2009年   659篇
  2008年   511篇
  2007年   452篇
  2006年   578篇
  2005年   462篇
  2004年   446篇
  2003年   423篇
  2002年   401篇
  2001年   672篇
  2000年   582篇
  1999年   461篇
  1998年   252篇
  1997年   240篇
  1996年   211篇
  1995年   227篇
  1994年   235篇
  1993年   221篇
  1992年   373篇
  1991年   403篇
  1990年   382篇
  1989年   397篇
  1988年   361篇
  1987年   341篇
  1986年   368篇
  1985年   373篇
  1984年   350篇
  1983年   323篇
  1982年   233篇
  1981年   218篇
  1980年   198篇
  1979年   246篇
  1978年   167篇
  1977年   144篇
  1976年   127篇
  1975年   127篇
  1974年   134篇
  1973年   130篇
  1972年   111篇
  1968年   100篇
排序方式: 共有10000条查询结果,搜索用时 7 毫秒
911.
The diagnosis of sudden infant death syndrome (SIDS) has been an enigma to medical examiners and coroners for decades. The recent drastic decrease in the number of SIDS cases has been associated with infants sleeping supine instead of prone. The apparent relation between sleeping position and SIDS has led to the marketing of several positioning sleep aids. We report a case of the improper use of one such device which resulted in the death of an infant.  相似文献   
912.
A retrospective analysis of 68 cases of fatal childhood pedestrian accidents in South Australia that occurred over a 20-year period from January 1977 to December 1996 was undertaken. The age range was 12 months to 16 years (average, 7.6 years), with a male to female ratio of 41:27. The most common site of significant injury was the head (91.2%), followed by the abdomen (50%), chest (47.1%), and neck (38.2%). The most frequently encountered significant injury combinations involved the head, chest, and abdomen (14.7%); the head and chest (11.8%); and the head, neck, and abdomen (11.8%). Injuries were severe, consisting of extensive compound and comminuted skull fractures, neck fractures, and massive intraparenchymal brain and internal organ damage with avulsions and fragmentation. Non-life-threatening limb injuries occurred in 88% of cases. A distinct subgroup involved infants and younger children playing in driveways at home who were hit by reversing vehicles. The injuries were often of such a severe nature that death was instantaneous and with no possibility of successful medical intervention. More deaths occurred during the winter than summer months.  相似文献   
913.
Olanzapine is an antipsychotic drug that has been on the market since 1996. Olanzapine-related deaths are very rare; the literature reports only one. However, in a recent 5-month period one medical examiner's office found two such cases that are reported in this paper. One is a suicide and the other is not. The toxicologic and anatomic findings for each are described. Blood olanzapine concentrations ranged from 0.237 microg/ml for one to 0.675 microg/ml for the other. Gastric content concentrations also exhibited a wide range, varying from 0.197 microg/ml to 17.400 microg/ml for the other. Distribution studies of the liver, kidney, and brain produced nondetectable concentrations for the drug. There were no consistent pathologic anatomic findings for cause of death except for moderate coronary atherosclerosis in the nonsuicide case. Both deaths were attributed to olanzapine toxicity.  相似文献   
914.
The present study investigated the effect on witness confidence and accuracy of confusing questions often used by attorneys in court. Participants viewed a videotaped film and were individually questioned about the incident 1 week later. Half the participants were asked questions using six categories of confusing questions (negatives, double negatives, leading, multiple questions, complex syntax, and complex vocabulary); the remaining half were asked for the same information using simply phrased equivalents. Confusing questions reduced participant-witnesses' accuracy and suppressed confidence–accuracy relationships compared with the condition where simplified alternatives were asked. Witness performance was impaired by the fact that mock-witnesses rarely asked for a confusing question to be explained or qualified their answers. This experiment demonstrates the importance of ensuring that lawyers ask witnesses simple, clear, questions.  相似文献   
915.
916.
917.
Forensic psychiatric services in British Columbia   总被引:1,自引:0,他引:1  
  相似文献   
918.
919.
920.
Hair samples of eight postmortem cases were analyzed in segments of 1 to 3 cm for cocaine, benzoylecgonine and cocaethylene. Samples were prepared for analysis by digestion in 0.1 M HCl and subsequent extraction with mixed-mode solid-phase extraction columns. Measurement was made by reversed-phase, narrow-bore HPLC and fluorescence detection using two laboratory-made internal standards. The concentrations were in the region of 0.29-316 ng/mg of hair for cocaine, 0.43-141 ng/mg of hair for benzoylecgonine and 0.93-1.83 ng/mg of hair for cocaethylene. All eight investigated cases had cocaine-positive segments. In six of the cases, all segments were positive, suggesting regular cocaine use and two showed in-between negative segments indicating an interruption or a change of the abuse intensity. The results showed a second, remarkable observation, i.e. enormous concentration differences (factor >150) for both cocaine and benzoylecgonine between the different subjects. Furthermore, interindividual cocaine/benzoylecgonine ratios ranged from 0.02 to 8.43. We believe these observations could in part be attributed to both some of the still existing limitations in the analytical approach(es), especially the mandatory hair washing steps, and in our still too limited knowledge of the hair incorporation processes. Nevertheless, in some cases, segmental analysis proved to be an important tool to distinguish, together with postmortem examination, deadly chronic abuse from single acute drug overdosage.  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