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   9055篇
  免费   219篇
各国政治   281篇
工人农民   400篇
世界政治   537篇
外交国际关系   250篇
法律   6158篇
中国政治   62篇
政治理论   1539篇
综合类   47篇
  2020年   97篇
  2019年   118篇
  2018年   219篇
  2017年   186篇
  2016年   258篇
  2015年   135篇
  2014年   168篇
  2013年   736篇
  2012年   299篇
  2011年   284篇
  2010年   181篇
  2009年   194篇
  2008年   207篇
  2007年   238篇
  2006年   250篇
  2005年   574篇
  2004年   308篇
  2003年   233篇
  2002年   195篇
  2001年   328篇
  2000年   305篇
  1999年   240篇
  1998年   97篇
  1997年   78篇
  1996年   79篇
  1995年   81篇
  1994年   83篇
  1993年   70篇
  1992年   170篇
  1991年   176篇
  1990年   170篇
  1989年   191篇
  1988年   169篇
  1987年   187篇
  1986年   170篇
  1985年   178篇
  1984年   138篇
  1983年   161篇
  1982年   99篇
  1981年   107篇
  1980年   78篇
  1979年   113篇
  1978年   86篇
  1977年   77篇
  1976年   67篇
  1975年   61篇
  1974年   80篇
  1973年   73篇
  1971年   67篇
  1970年   58篇
排序方式: 共有9274条查询结果,搜索用时 15 毫秒
991.
Industry stakeholders and Internet experts generally agree that networks using Internet Protocol version 6 (IPv6), an Internet communications standard which is being promoted strongly by many parties, would be technically superior to today’s networks, which are largely based on IPv4. The improvements designed for IPv6 could provide numerous benefits to Internet users, network administrators, and applications developers; among these potential benefits are cost reductions due to improved security and increased efficiency, improvements to existing products and services, and innovations leading to new products and services. However, there is wide disagreement about the characteristics and timing of benefits associated with IPv6, and the costs associated with the transition could be substantial. In this paper, we will discuss the likely costs of a transition to IPv6 for the major stakeholders and the potential benefits. Subsequently, we will introduce the cost impact of an accelerated adoption case and discuss potential ways in which the government could become involved in the process. This paper is based on a broader study funded by the National Telecommunications and Information Administration (NTIA) and National Institute of Standards and Technology (NIST). We wish to thank Greg Tassey, Fred Lee, Tim Sloan, B. Keith Fulton, John Streck, and Baran Erkel for comments and suggestions on earlier versions of this paper.  相似文献   
992.
993.
994.
995.
996.
In only nine of approximately 600 cases of child molestation in New Hampshire and Vermont was the perpetrator found to be a woman. Case histories and some testing data show a history of sexual assault as a child, frequent offense in the company of a dominant male partner, and a major disinhibition as a result of severe character disorder or limited intelligence. These factors not only interfered with maternal bonding and nurturing behavior but also contributed to suspension of judgment about the appropriateness of sexual contact with children.  相似文献   
997.
998.
999.
The toxicological findings of a multi-drug related fatal poisoning are described here. A 35-year-old Caucasian male found dead on the kitchen floor was a known user of abused drugs and had been taking aspirin alone or in combination with phenacetin and caffeine for the relief of joint pains. The gross examination of the organs at autopsy revealed slight grooving of the uncus and various stages of necrosis in the renal papillae. Histological examination confirmed the gross appearance of pulmonary congestion and edema, cerebral edema and interstitial nephritis of the tubules. Toxicological evaluation of the blood and urine samples disclosed the presence of propoxyphene (51 and 250 mg/l), salicylate (185 and 2750 mg/l), caffeine (16 and 37 mg/l), and phenacetin (9.6 and 20 mg/l). Furthermore, acetaminophen also was present in the plasma (54 mg/l) and urine. A gas liquid chromatographic method for simultaneous analysis of phenacetin and caffeine utilizing a nitrogen phosphorus detector was proposed.  相似文献   
1000.
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