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   10216篇
  免费   324篇
各国政治   289篇
工人农民   486篇
世界政治   605篇
外交国际关系   311篇
法律   6573篇
中国共产党   34篇
中国政治   127篇
政治理论   1979篇
综合类   136篇
  2021年   63篇
  2020年   149篇
  2019年   136篇
  2018年   207篇
  2017年   244篇
  2016年   279篇
  2015年   227篇
  2014年   224篇
  2013年   838篇
  2012年   242篇
  2011年   285篇
  2010年   215篇
  2009年   279篇
  2008年   336篇
  2007年   348篇
  2006年   332篇
  2005年   302篇
  2004年   295篇
  2003年   242篇
  2002年   238篇
  2001年   352篇
  2000年   326篇
  1999年   258篇
  1998年   155篇
  1997年   112篇
  1996年   140篇
  1995年   115篇
  1994年   130篇
  1993年   126篇
  1992年   198篇
  1991年   250篇
  1990年   212篇
  1989年   198篇
  1988年   221篇
  1987年   201篇
  1986年   220篇
  1985年   192篇
  1984年   163篇
  1983年   157篇
  1982年   102篇
  1981年   122篇
  1980年   101篇
  1979年   102篇
  1978年   89篇
  1977年   77篇
  1976年   64篇
  1975年   64篇
  1974年   65篇
  1973年   77篇
  1971年   50篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
841.
842.
843.
844.
Genetic marker analysis is a powerful tool for solving paternity-related problems when the putative father is missing. This report describes the first time this approach was employed in Chile to solve such a problem. In the case presented, the alleged father was missing as a result of the political detentions that took place in Chile during 1973. It was not possible to obtain any biological sample from him because he was missing. Thus, the case was resolved by means of genetic marker analysis of the alleged father's close relatives.  相似文献   
845.
A case of a 16-year-old male who committed a sexual matricide following years of mother-son incest is reported. After murdering his mother by strangulation, which itself was sexually arousing, the youngster engaged in both vaginal and anal necrophilia. The homicide occurred while the perpetrator was in a dissociative state and experiencing what has been referred to as a catathymic crisis: the sudden release of emotionally charged psychic conflict and tension, resulting in extreme violence within an interpersonal bond. Discussion of maternal image and maternal sexual conduct in relationship to the psychosexual development of adolescent males offers insight into the motivation in this extremely rare case.  相似文献   
846.
In order to establish an animal model for entomotoxicological studies, the kinetics of morphine elimination from blood after a single intravenous injection of morphine and the concentration of morphine in tissues following a continuous perfusion were studied. The aim of these experiments was to obtain controlled morphine tissue concentrations similar to those encountered in fatal human heroin overdoses. These tissues can be used as a food source for developing fly larvae in entomotoxicological studies. In the single injection experiment, seven rabbits were administered 1 or 2 mg/kg body weight of morphine chlorhydrate via the main ear artery. Blood samples of 200 microL were removed regularly via a catheter. Morphine concentration was determined using RIA techniques. Morphine was found to be first rapidly distributed and then slowly eliminated, following a two-exponential equation. Elimination of morphine from blood can be described as a two-compartment model. Constants of the equation were determined using the Kaleidagraph program. Using those constants, the main pharmacokinetics parameters were calculated. Results of these parameters showed the following: clearance from 13.3 to 16.2 L.h.1, half-life of the distribution phase from 0.6 to 0.9 min, and half-life of the elimination phase from 21 to 26 min. These results were used to calculate the rate of perfusion of morphine for rabbits to obtain desired, controlled, and constant concentrations of morphine in tissues. In the second experiment, three rabbits received a perfusion of morphine intravascularly at a rate of 2 mg/kg/h for a period of 3 h. These rabbits were sacrificed and analyses performed on several abdominal and thoracic organs. Results showed that the concentrations of morphine differed according to the organ analyzed, but were reproducible for organs between animals. These concentrations were similar to those normally encountered in cases of human death due to heroin overdoses.  相似文献   
847.
A new method for determination of lysergic acid diethylamide (LSD) in body fluids by high-performance liquid chromatography and fluorescence detection was developed based on previously published methods. The new method is suitable for confirmation of samples tested positive by immunoassay, avoiding loss of LSD by absorption to surfaces. The reduced loss of LSD results in improved sensitivity. This is achieved by adding ethylene glycol to the samples, which cover glass surfaces. This principle can similarly be used to improve analysis of other drugs. Body fluids for analysis included urine and whole blood. An internal standard was applied for quantification of LSD. The new method offers satisfying precision data and has a detection limit of less than 0.05 ng/nL.  相似文献   
848.
Law plays crucial roles in the field of public health, from defining the power and jurisdiction of health agencies, to influencing the social norms that shape individual behavior. Despite its importance, public health law has been neglected. Over a decade ago, the Institute of Medicine issued a report lamenting the state of public health administration, generally, and calling, in particular, for a revision of public health statutes. The Article examines the current state of public health law. To help create the conditions in which people can be healthy, public health law must reflect an understanding of how public health agencies work to promote health, as well as the political and social contexts in which these agencies operate. The authors first discuss three prevailing ways in which the determinants of health are conceptualized, and the political and social problems each model tends to create for public health efforts. The analysis then turns to the core functions of public health, emphasizing how law furthers public health work. The Article reports the results of a fifty-state survey of communicable disease control law, revealing that few states have systematically reformed their laws to reflect contemporary medical and legal developments. The Article concludes with specific guidelines for law reform.  相似文献   
849.
This research examines the differential effects of structural conditions on race-specific victim and offender homicide rates in large U.S. cities in 1990. While structural theories of race relations and criminological explanations are reviewed, particular attention is given to those structural theories that highlight racial competition, economic and labor market opportunity, and racial segregation as essential for an examination of racially disaggregated homicide offending. The effects of these and other structural conditions are estimated for four racially distinct homicide offending models—black intraracial, white intraracial, black interracial, and white interracial homicides. The results suggest that the structural conditions that lead to race-specific victim and offender homicide rates differ significantly among the four models. Economic deprivation and local opportunity structures are found to influence significantly the rates of intraracial homicide offending, while racial inequality contributes solely to black interracial homicide rates. In addition, our findings indicate that blacks and whites face different economic and social realities related to economic deprivation and social isolation. The differential impact of these structural conditions and other labor market factors are discussed.  相似文献   
850.
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