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   19604篇
  免费   1422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   13802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 15 毫秒
121.
Bioaerosol data is often used in cases of building mold infestation alleging damage or adverse health effects upon occupants, despite the lack of consistent sampling and analytical protocols and numerical health-based standards. The most fundamental problem in these scenarios is defining a “significant” difference between a suspect indoor environment and the reference environment, regardless of the type of sampling and analysis utilized. Data interpretation focused upon differences in absolute numerical concentrations of fungi is subject to wide differences in expert opinion. On the other hand, an objective quantification of differences can be expressed in terms of probability and better meets criteria established in evidentiary rules.  相似文献   
122.
Despite its original purpose to protect and rehabilitate wayward children, the juvenile system has grown more punitive and has embraced the use of harsher punishments, including execution, for juvenile offenders. Relatively little is known, however, about public attitudes toward the use of capital punishment for juveniles. This research explored the determinants of death penalty opinion, identified the minimum age at which respondents were willing to allow a juvenile to be put to death and examined the willingness of respondents to support an alternative sentence of life without the possibility of parole (LWOP). The results suggested that, while one-quarter of the sample was willing to execute juveniles who were fifteen and under at the time of the crime, there was less support for the execution of juveniles than of adults. In addition, of those who supported the use of the death penalty for juveniles, almost one-half would support LWOP as an alternative to the death penalty.  相似文献   
123.
Der Begriff der Landeskultur umfasst alle Maßnahmen zur Verbesserung der land- und forstwirtschaftlichen Nutzung des Bodens einschließlich der Erhaltung der Kulturlandschaft. Landeskultur ist somit alles Planen und Handeln mit dem Ziel, die Umwelt als gegebenes Naturraumpotential, insbesondere Wasser, Boden, Luft und die dazugehörigen Natur-, Kultur- und Sachgüter optimal zu erhalten, gestalten und rationell zu nutzen sowie dieses Potential mit bestmöglicher Qualität als natürliche und kulturelle Lebensgrundlage für die Allgemeinheit nachhaltig zu sichern. Landeskultur dient somit auch der Belebung und Werterhöhung der gebauten und gepflanzten Umwelt. Dies schließt auch und gerade die kulturelle Seite einschließlich Kulturlandschaften mit ein. Dabei ist es bis zur Überprüfung durch das BVerfG noch hinnehmbar, dass der Begriff „Landeskultur“ in Art. 89 Abs. 3 GG wegen der Mischkompetenz von Bund und Land vom BVerwG enger ausgelegt wird als in anderen Rechtsvorschriften.  相似文献   
124.
Recent studies point to the potential theoretical and practical benefits of focusing police resources on crime hot spots. However, many scholars have noted that such approaches risk displacing crime or disorder to other places where programs are not in place. Although much attention has been paid to the idea of displacement, methodological problems associated with measuring it have often been overlooked. We try to fill these gaps in measurement and understanding of displacement and the related phenomenon of diffusion of crime control benefits. Our main focus is on immediate spatial displacement or diffusion of crime to areas near the targeted sites of an intervention. Do focused crime prevention efforts at places simply result in a movement of offenders to areas nearby targeted sites—“do they simply move crime around the corner”? Or, conversely, will a crime prevention effort focusing on specific places lead to improvement in areas nearby—what has come to be termed a diffusion of crime control benefits? Our data are drawn from a controlled study of displacement and diffusion in Jersey City, New Jersey. Two sites with substantial street‐level crime and disorder were targeted and carefully monitored during an experimental period. Two neighboring areas were selected as “catchment areas” from which to assess immediate spatial displacement or diffusion. Intensive police interventions were applied to each target site but not to the catchment areas. More than 6,000 20‐minute social observations were conducted in the target and catchment areas. They were supplemented by interviews and ethnographic field observations. Our findings indicate that, at least for crime markets involving drugs and prostitution, crime does not simply move around the corner. Indeed, this study supports the position that the most likely outcome of such focused crime prevention efforts is a diffusion of crime control benefits to nearby areas.  相似文献   
125.
Fragment     
  相似文献   
126.
127.
Presents forensic medical characteristics of the specific features of stabbed and cut injuries of human skin and jersey. Suggests a complex of signs that will help determine some structural parameters of a knife blade and the conditions of its interaction with the injured site of human body.  相似文献   
128.
The impact of high temperatures (24 to 39 degrees C) and low to moderately high humidities (20 to 70%) on the applicability of TLC systems for drug identification was studied during a 6 month climatologic cycle in Burkina Faso (West Africa). In general, the Rf values as observed on the plates were found to be substantially affected as compared with values obtained at temperate climates. Some TLC systems were more affected than others and the largest deviations of up to 30 Rf units were at low humidities. Tropical conditions also had a negative effect on the reproducibility of Rf values. However, when an Rf-correction procedure was applied, using reference mixtures of known drugs on each plate, accuracy as well as reproducibility of the resulting Rfc values were drastically improved and data thus corrected were found to be compatible with existing TLC data bases developed under moderate climatological conditions. The impact of high to extremely high humidities (70 to 100%) remains to be investigated.  相似文献   
129.
Veto Players and Civil War Duration   总被引:1,自引:0,他引:1  
Civil wars show a remarkable variation in how long they last. Some end within days; others continue for decades. What explains the extreme intractability of some wars while others are resolved quickly? This article argues that conflicts with multiple actors who must approve a settlement (veto players) are longer because there are fewer acceptable agreements, information asymmetries are more acute, and shifting alliances and incentives to hold out make negotiation more difficult. This veto player approach to explaining variation in civil war duration is tested using a new dataset containing monthly data on all parties to each civil war begun since World War II. The statistical analysis shows a strong correlation between the number of veto players and the duration of civil war.  相似文献   
130.
Washington University v. Catalona revolves around ownership of tissue samples provided by patients for research purposes, raising significant ethical and legal questions concerning patient rights, current human research practices, and the treatment of samples as capital resources by the research institution.  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