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   13951篇
  免费   503篇
各国政治   817篇
工人农民   571篇
世界政治   1071篇
外交国际关系   673篇
法律   7786篇
中国共产党   3篇
中国政治   103篇
政治理论   3295篇
综合类   135篇
  2023年   79篇
  2021年   80篇
  2020年   189篇
  2019年   254篇
  2018年   386篇
  2017年   401篇
  2016年   452篇
  2015年   280篇
  2014年   301篇
  2013年   1810篇
  2012年   397篇
  2011年   387篇
  2010年   330篇
  2009年   352篇
  2008年   453篇
  2007年   455篇
  2006年   449篇
  2005年   406篇
  2004年   416篇
  2003年   360篇
  2002年   369篇
  2001年   366篇
  2000年   362篇
  1999年   301篇
  1998年   197篇
  1997年   205篇
  1996年   180篇
  1995年   158篇
  1994年   166篇
  1993年   187篇
  1992年   249篇
  1991年   259篇
  1990年   237篇
  1989年   233篇
  1988年   223篇
  1987年   217篇
  1986年   223篇
  1985年   201篇
  1984年   195篇
  1983年   196篇
  1982年   122篇
  1981年   121篇
  1980年   95篇
  1979年   124篇
  1978年   96篇
  1977年   90篇
  1976年   73篇
  1975年   73篇
  1974年   91篇
  1973年   81篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
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   
102.
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   
103.
Many attempts have been made over the last several decades to improve communication among law enforcement agencies. This article is a case study of a “low-level” data sharing project in Florida that could serve as a national model. The Florida Law Enforcement Data Sharing Consortium is a partnership between the University of Central Florida and more than one hundred law enforcement agencies. It offers an inexpensive, yet technically advanced alternative to the proprietary data sharing model. Its distributed architecture was endorsed by the Markle Foundation, the 9/11 Commission, and the 2004 National Security Act. Civil liberties concerns raised by this and other types of data sharing projects are discussed.  相似文献   
104.
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   
105.
Out of Harm's Way?: Illicit Drug Use, Medicalization and the Law   总被引:1,自引:0,他引:1  
  相似文献   
106.
The increased risk of child maltreatment in the presence of domestic violence is well documented, but much remains unknown about factors that modify this relationship. This study investigates the roles of risk and protective factors in the relationship between domestic violence and being reported to the Department of Social Services for child maltreatment. Consistent with the literature, we find a significant overlap between domestic violence and maltreatment. Young maternal age, low education, low income, and lack of involvement in a religious community add to the risk for maltreatment associated with domestic violence. Separation between the maternal caregiver and her partner significantly reduces the risk for maltreatment when domestic violence is reported. A significant reduction in the risk for maltreatment is also found with higher levels of support from the maternal caregiver reported by the child in the context of domestic violence.  相似文献   
107.
Child custody evaluators with experience in mediation may be tempted to use mediation skills and strategies in their evaluation processes. This article explores the benefits and risks of blending mediation with evaluation, comparing the perspectives of professionals and clients.  相似文献   
108.
109.
California is now in its 11th year of mandatory child custody mediation, with a current yearly case volume statewide estimated at 65,494. This article profiles the variations in programs and mediation styles in 56 of the state's 58 Superior Courts. Two research studies provide the basis for the information on program structures, case activity, procedures, agreement formats, recommendations, facilities, security, and fees.  相似文献   
110.
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