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   18582篇
  免费   558篇
各国政治   796篇
工人农民   757篇
世界政治   1520篇
外交国际关系   680篇
法律   11060篇
中国共产党   2篇
中国政治   122篇
政治理论   4028篇
综合类   175篇
  2021年   102篇
  2020年   248篇
  2019年   297篇
  2018年   391篇
  2017年   442篇
  2016年   476篇
  2015年   325篇
  2014年   380篇
  2013年   1867篇
  2012年   455篇
  2011年   483篇
  2010年   384篇
  2009年   432篇
  2008年   492篇
  2007年   507篇
  2006年   490篇
  2005年   434篇
  2004年   436篇
  2003年   452篇
  2002年   405篇
  2001年   732篇
  2000年   658篇
  1999年   554篇
  1998年   302篇
  1997年   258篇
  1996年   213篇
  1995年   225篇
  1994年   262篇
  1993年   240篇
  1992年   361篇
  1991年   387篇
  1990年   350篇
  1989年   356篇
  1988年   332篇
  1987年   344篇
  1986年   352篇
  1985年   345篇
  1984年   296篇
  1983年   330篇
  1982年   264篇
  1981年   251篇
  1980年   184篇
  1979年   253篇
  1978年   179篇
  1977年   148篇
  1976年   138篇
  1975年   122篇
  1974年   141篇
  1973年   121篇
  1972年   116篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
142.
In a case of suicidal application of electricity differences between the rectal temperature of the body and the suspected time of death were observed.In order to answer the question whether an electric current from hand to hand over >30 min led to a rise in body temperature FEM-based computer simulations and animal experiments were carried out. Both resulted in a warming of the soft parts in the arm without warming the body core. Thus a temperature-based estimation of the time since death can also be used in cases with electricity as the cause of death. Besides, in the animal experiment we found a spontaneous rise in the body core temperature even without application of electricity which may be a reason for the typical temperature plateau after death.  相似文献   
143.
144.
145.
146.
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   
147.
148.
The end of the twentieth century was marked by a sea change in global governance in the realm of intellectual property rights (IPRs). Whereas countries historically retained substantial autonomy with regard to what they defined as intellectual "property" and the rights granted to the owners of intellectual property, the 1990s witnessed the establishment of new global obligations regarding national practices. This paper focuses on the case of software "piracy" to assess the mechanisms by which the new global obligations for the treatment of IPRs are transmitted from the international to the national levels. We first consider a set of national-level factors that many scholars have shown to be important determinants of IPR policy. We then supplement the standard emphasis on domestic factors with an analysis of new transnational factors: countries' multilateral obligations under the World Trade Organization's (WTO) Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS) and bilateral pressures from the United States to increase the protection of IPRs. Population-averaged panel data models are used to assess the effects of these national and transnational determinants on levels of software piracy in 80 countries from 1994 to 2002. Our results indicate that membership in the WTO and bilateral pressures from the United States—particularly pressures that offer reciprocal concessions—lead to substantial increases in levels of protection in rich and poor countries. There is, in short, a new international political economy of intellectual property.  相似文献   
149.
150.
Eight homicidal youths were assessed for language disorders and psychiatric diagnoses using a battery of standardized language tests and the Diagnostic Interview for Children and Adolescents. Both language disorders and Diagnostic and Statistical Manual III-R psychiatric diagnoses were present in all subjects.  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