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   18658篇
  免费   1260篇
各国政治   831篇
工人农民   898篇
世界政治   1219篇
外交国际关系   619篇
法律   12895篇
中国共产党   2篇
中国政治   108篇
政治理论   3257篇
综合类   89篇
  2023年   84篇
  2021年   105篇
  2020年   462篇
  2019年   484篇
  2018年   632篇
  2017年   646篇
  2016年   725篇
  2015年   563篇
  2014年   578篇
  2013年   2006篇
  2012年   588篇
  2011年   586篇
  2010年   581篇
  2009年   609篇
  2008年   563篇
  2007年   582篇
  2006年   555篇
  2005年   466篇
  2004年   461篇
  2003年   379篇
  2002年   432篇
  2001年   690篇
  2000年   624篇
  1999年   498篇
  1998年   245篇
  1997年   179篇
  1996年   203篇
  1995年   197篇
  1994年   172篇
  1993年   178篇
  1992年   310篇
  1991年   317篇
  1990年   301篇
  1989年   281篇
  1988年   305篇
  1987年   263篇
  1986年   323篇
  1985年   317篇
  1984年   251篇
  1983年   233篇
  1982年   184篇
  1981年   156篇
  1980年   144篇
  1979年   222篇
  1978年   118篇
  1977年   92篇
  1975年   94篇
  1974年   124篇
  1973年   79篇
  1972年   78篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
112.
113.
114.
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   
115.
The legislator, in the German Federal Republic, has opted for a specific legal solution in relation to the protection of the embryo. Carola Müller, in this article, describes this regulation as well as the reasons that have led to its adoption. The article finishes with an exposition of the existing social discussion in German society and the effect that the law has had.  相似文献   
116.
This article examines the question of trust in Bosnia and Herzegovina with a special focus on the role of ethnicity. We find generalised trust to be low and declining in Bosnia and Herzegovina. Moreover, generalised trust is negatively affected by the degree of ethnic heterogeneity in the region. However, a further examination of trust reveals a more complex relationship between ethnicity and trust: people tend to show low levels of trust in all other people irrespective of their ethnic belongings. We argue that ethnic distribution might capture some other regional specific characteristics that also affect the level of trust.  相似文献   
117.
More than a decade after NAFTA (North American Free Trade Agreement) entered into force, the environmental effects of agricultural trade liberalization in Mexico are still controversial, emerging, and not fully understood. This paper contributes to the literature that aims to explore trends in input use in the agricultural sector in Mexico during the post-NAFTA period among both commercial/industrial and traditional/rainfed farmers, and examines the influence of the national and multilateral institutional framework on these outcomes. We decompose the post-NAFTA agricultural production data into scale, technique and composition effects to estimate the impact that trade liberalization has had on the use of fertilizer and land use, two key agricultural inputs for which reliable aggregate data is available. We conclude that among commercial farmers patterns of crop type specialization and significant technological improvements have led to some declines in fertilizer use but they have been offset by growth in fertilizer use associated with growing agricultural output. Among traditional farmers increased output and specialization in land-intensive grain crops are contributing to an increase in land under cultivation and technological improvements show the potential, but not yet not the strength, to counteract these effects. We analyse the environmental institutional framework and rural development plans, observing that institutional weaknesses have, in several instances, reduced the environmental benefit of technique and composition effects. We conclude with recommendations about how the Mexican agricultural sector might reap the environmental benefits of international agricultural trade.  相似文献   
118.
This article reports the results of a study of the antecedents of long-term success in community mediation. Seventy-three mediation sessions were recorded and content analyzed. The participants were interviewed at two points: immediately after mediation and 4 to 8 months later. No relationship was found between the quality of the agreements—i.e., the extent to which they solved immediate problems- and long-term success as measured by compliance, improved relations between the parties, and the absence of new problems. On the other hand, joint problem solving by the disputants was related to complainant perceptions of improved relations with the other party. Also respondent perceptions that the mediation had been fair and that all the problems had come out were related to all aspects of long-term success in the eyes of the complainant. The latter results support a procedural justice analysis of mediation and underline the importance of mediator attention to the respondent.  相似文献   
119.
120.
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