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   18540篇
  免费   511篇
各国政治   820篇
工人农民   751篇
世界政治   1190篇
外交国际关系   541篇
法律   11587篇
中国共产党   3篇
中国政治   119篇
政治理论   3879篇
综合类   161篇
  2020年   196篇
  2019年   291篇
  2018年   378篇
  2017年   425篇
  2016年   417篇
  2015年   302篇
  2014年   323篇
  2013年   1859篇
  2012年   428篇
  2011年   472篇
  2010年   388篇
  2009年   451篇
  2008年   502篇
  2007年   469篇
  2006年   496篇
  2005年   450篇
  2004年   449篇
  2003年   431篇
  2002年   432篇
  2001年   649篇
  2000年   593篇
  1999年   447篇
  1998年   267篇
  1997年   237篇
  1996年   243篇
  1995年   227篇
  1994年   219篇
  1993年   231篇
  1992年   384篇
  1991年   417篇
  1990年   394篇
  1989年   399篇
  1988年   368篇
  1987年   375篇
  1986年   411篇
  1985年   396篇
  1984年   367篇
  1983年   351篇
  1982年   237篇
  1981年   214篇
  1980年   185篇
  1979年   246篇
  1978年   158篇
  1977年   171篇
  1976年   150篇
  1975年   122篇
  1974年   148篇
  1973年   151篇
  1972年   135篇
  1969年   104篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
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   
102.
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   
103.
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   
104.
Fragment     
  相似文献   
105.
Toxicologic findings in the USS Iowa disaster.   总被引:5,自引:0,他引:5  
The toxicologic results from the 47 victims of the explosion on the USS Iowa are presented. Good correlation between carboxyhemoglobin saturations and cause of death was found. There were no correlations between blood cyanide concentrations and causes of death. Volatile analysis suggested postmortem ethanol production rather than antemortem ethanol ingestion. No drugs except nicotine were detected in any of the victims.  相似文献   
106.
107.
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   
108.
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   
109.
In this study, a new method was developed for the impurity profiling of illicit MDMA tablets. The extraction efficiency, linearity, repeatability and reproducibility of the method were evaluated. Eighty two MDMA tablets coming from presumed unrelated large seizures in 2004 (n >500 tablets) were analyzed by gas chromatography mass spectrometry (GC-MS) in order to assess the discrimination power of the method. The latter was found to be practical, robust, relatively easy to perform, highly discriminative and yielding good chromatography. In addition, some new impurities were detected and identified. Their chemical structures and mass spectra are reported.  相似文献   
110.
The role of the state is changing under the impact of, for example, globalization. The changes have been variously understood as the new public management (NPM), the hollowing–out of the state and the new governance. This special issue of Public Administration explores the changing role of the state in advanced industrial democracies. It focuses on the puzzle of why states respond differently to common trends.
This introductory article has three aims. First, we provide a brief review of the existing literature on public sector reform to show that our approach is distinctive. We argue that the existing literature does not explore the ways in which governmental traditions shape reform. Second, we outline an interpretive approach to the analysis of public sector reform built on the notions of beliefs, traditions, dilemmas and narratives. We provide brief illustrations of these ideas drawn from the individual country articles. Finally, we outline the ground covered by all the chapters but we do not summarize and compare their experiences of reform. That task is reserved for the concluding article.  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