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   7145篇
  免费   215篇
各国政治   235篇
工人农民   245篇
世界政治   481篇
外交国际关系   214篇
法律   4886篇
中国政治   47篇
政治理论   1215篇
综合类   37篇
  2020年   93篇
  2019年   112篇
  2018年   130篇
  2017年   159篇
  2016年   162篇
  2015年   109篇
  2014年   157篇
  2013年   643篇
  2012年   171篇
  2011年   186篇
  2010年   159篇
  2009年   156篇
  2008年   187篇
  2007年   214篇
  2006年   222篇
  2005年   179篇
  2004年   185篇
  2003年   201篇
  2002年   164篇
  2001年   314篇
  2000年   291篇
  1999年   220篇
  1998年   85篇
  1997年   69篇
  1996年   76篇
  1995年   68篇
  1994年   76篇
  1993年   61篇
  1992年   141篇
  1991年   153篇
  1990年   136篇
  1989年   155篇
  1988年   134篇
  1987年   149篇
  1986年   134篇
  1985年   152篇
  1984年   118篇
  1983年   139篇
  1982年   94篇
  1981年   93篇
  1980年   69篇
  1979年   99篇
  1978年   74篇
  1977年   66篇
  1976年   57篇
  1975年   46篇
  1974年   57篇
  1973年   59篇
  1971年   50篇
  1970年   46篇
排序方式: 共有7360条查询结果,搜索用时 15 毫秒
871.
Supravital electrical excitability of muscles   总被引:1,自引:0,他引:1  
A new method of postmortem electrical stimulation of muscles, measuring the force of the reaction against time, is presented. Preliminary investigations have yielded the following results: The maximum force of reaction in response to a definitive stimulation, measured by a sensitive force transducer, decreases in proportion to the post mortem interval. Using this method, the mechanical reactions of muscles by electrical stimulation can be demonstrated over a much longer postmortem period as these movements are visible. The duration of postmortem reaction of different muscles seems to be much more uniform than was previously assumed. Occasionally, reactions of the M. orbicularis oculi can be seen for the longest time. The basal muscular tonus changes relative to time. The time course of a single force reaction also changes relative to the postmortal interval: the reaction becomes slower. It has been theoretically established that measurement of influencing factors such as temperature and pH in the tested muscle will enable the time of death to be more precisely estimated.  相似文献   
872.
The purpose of this study is to examine the participation of criminology and criminal justice graduate departments at the 1977-1979 American Society of Criminology meetings. Results show that institutional prestige. not productivity, is the leading predictor of meeting participation. In addition, meeting participation does not appear to be influenced by meeting site. Finally, it is suggested that criminologists focus more attention upon professional activities in order to facilitate our understanding of criminology as a science.  相似文献   
873.
There has been numerous attempts to model the relationship between unemployment, inflation, other economic variables and government popularity in a variety of industrial countries. However, there is conflicting evidence about the magnitude and significance of effects both between different countries, and within the same country at different points of time. The purpose of this article is to examine the existing literature, to provide a critique of the theoretical and statistical validity of many existing studies, and to specify and estimate a dynamic model of the relationship between inflation, unemployment and government popularity in three countries over the post-war period. This model is a multivariate transfer function with an autoregressive-moving average error structure which has been developed in its general form by Box and Jenkins. The results demonstrate significant relationships between inflation, unemployment and government popularity, but relationships which are relatively weak and unstable over time.  相似文献   
874.
Microbiologic analysis of different soil samples was undertaken to assess the value of this method for forensic purposes. Three groups of micro-organisms were isolated on selective media: bacteria, fungi, and actinomycetes. Comparison of the morphology of the colonies led to the conclusion of non identity of the soil samples under examination. The method was applied to soil traces on articles of clothing, trousers, shoes, and stockings. It was found that the soil did not originate from the suspected scene of a crime. Examination of the microbiologic soil composition does not provide an absolute certainty of identity, but it is highly reliable.  相似文献   
875.
Alcohol screening with the Alcoscan test strip in forensic praxis   总被引:1,自引:0,他引:1  
The Alcoscan test strip was applied as an assay for the screening of alcohol in vitreous humor and urine samples in autopsy cases and in saliva from drunken drivers. The method gives instant and reliable semi-quantitative information on the presence of alcohol and is valuable when considering the necessity of chemical sampling especially during autopsy.  相似文献   
876.
Sudden and unexpected death and violent death of persons with a high risk of acquiring HIV-infections, especially homosexual males and intravenous drug abusers, have to be investigated by forensic autopsies. Therefore every forensic pathologist has to be aware of this infection and should try to make the proper diagnosis. Three typical cases are described: (1) suicide by hanging, (2) homicide by cutting the throat and (3) intravenous heroin overdose. Merely retrospectively it could be cleared up that the deceased were homosexual but did not manifestly suffer from AIDS. The morphological findings in the lymph nodes and the postmortem serological findings are described in detail.  相似文献   
877.
878.
879.
880.
The Pittsburgh Youth Study is a prospective longitudinal survey of three samples of Pittsburgh boys (each containing about 500 boys) initially studied in first, fourth, and seventh grades. The first two data collection waves yielded self-reported delinquency and combined delinquency seriousness scores (the combined scores based on information from boy, mother, and teacher) for the middle sample (up to an average age of 10.7 years) and oldest sample (up to an average age of 13.9 years). These scores were compared with records of petitions to the Allegheny County Juvenile Court for delinquency offenses before and up to six years after the assessments. The area under the ROC curve was used as a measure of validity. Concurrent validity was higher than predictive validity. The combined scale had similar concurrent validity but greater predictive validity than the self-report scale, and the combined scale also identified a greater number of boys as serious delinquents. Concurrent validity for admitting offenses was higher for Caucasians, but concurrent validity for admitting arrests was higher for African-Americans. There were no consistent ethnic differences in predictive validity. There was an increase in predictive validity, for both African-Americans and Caucasians, by combining self-report data with information from other sources. Afrer controlling for delinquency measures, African-Americans were more likely than Caucasians to be petitioned in the future, but not in the past. In this research, ethnic differences in official delinquency were partly attributable to ethnic differences in delinquent behavior and were not attributable to differential ethnic attrition or differential ethnic validity of measures of delinquent behavior.  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