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   2242篇
  免费   133篇
各国政治   126篇
工人农民   117篇
世界政治   174篇
外交国际关系   170篇
法律   1182篇
中国政治   17篇
政治理论   574篇
综合类   15篇
  2023年   23篇
  2022年   20篇
  2021年   25篇
  2020年   51篇
  2019年   73篇
  2018年   86篇
  2017年   106篇
  2016年   110篇
  2015年   74篇
  2014年   93篇
  2013年   337篇
  2012年   93篇
  2011年   78篇
  2010年   71篇
  2009年   75篇
  2008年   86篇
  2007年   104篇
  2006年   91篇
  2005年   86篇
  2004年   62篇
  2003年   74篇
  2002年   68篇
  2001年   36篇
  2000年   40篇
  1999年   38篇
  1998年   24篇
  1997年   22篇
  1996年   18篇
  1995年   18篇
  1994年   18篇
  1993年   9篇
  1992年   31篇
  1991年   20篇
  1990年   21篇
  1989年   21篇
  1988年   14篇
  1987年   10篇
  1986年   17篇
  1985年   22篇
  1984年   10篇
  1983年   16篇
  1982年   15篇
  1981年   8篇
  1980年   12篇
  1979年   4篇
  1975年   4篇
  1974年   5篇
  1973年   5篇
  1969年   4篇
  1965年   3篇
排序方式: 共有2375条查询结果,搜索用时 15 毫秒
151.
Allele frequencies for 16 short tandem repeats (STR) loci were determined with a sample of 230-300 unrelated individuals from the population of Rio de Janeiro, Brazil. The loci are the most commonly used in forensic and paternity testing, being analysed by the Identifiler (Applied Biosystems) and PowerPlex 2.1 (Promega) commercial kits. It was proved that Penta E and D18S51 are the most polymorphic loci.  相似文献   
152.
In recent years, there has been a surge in patenting by Belgian universities. It appears that this increase can be attributed to growth of biotechnology, where there is a greater propensity to patent, to a desire on the part of universities to enhance commercialization through technology transfer offices (TTOs), and to effective collaboration between universities and government-sponsored research centers. Our qualitative analysis reveals that patent statistics could be a misleading indicator of an individual university's technological productivity, since many inventions are developed at universities, yet applied by other institutions.  相似文献   
153.
1-Aryl-piperazine compounds are, depending on their substituents, selective for certain serotonin receptors and together with their easy availability and their so-called legal status, this group of psychoactive compounds are potential designer drugs-of-abuse. Internet in that respect is an important source of information and distribution facilities. Because this development may have consequences for the interpretation of future clinical and forensic toxicological case studies, some analytical aspects of 1-benzyl-piperazine (BZP), 1-[4-methoxyphenyl]-piperazine (pMeOPP) and 1-[3-trifluoromethylphenyl]-piperazine (TFMPP) were studied. BZP was not detected by the AxSYM FPIA technology designed to determine amphetamine-like compounds, but had showed some cross reactivity with EMIT d.a.u.. The cross reactivities at 300 and 12,000ng/ml (RS)-amphetamine equivalents were 0.4 and 1.3%, respectively. Although BZP was not identified directly by the REMEDi HS Drug Profiling System, it can be detected by this HPLC/UV scanning system. Using GC/NPD without derivatisation, BZP, pMeOPP and TFMPP can be analysed for and applying GC/MS without or with acetylation or trifluoroacetylation, these compounds can be identified unambiguously. The usefulness of GC/NPD and GC/MS in this respect was demonstrated by the quantitative and qualitative analysis of the content of a capsule with the synthetic stimulant A2, which proved to contain 86.4mg of BZP.  相似文献   
154.
The paper explains why the productivity of information technology (IT) in the service sector of the U.S. economy is increased by the provision of infratechnology. The size and growth of the service sector and its investment in IT are discussed, and a key fact and a key inference are developed. The fact: The absorption costs of IT are the vast majority of the IT investment costs to the service sector. The inference: Infratechnology investments are an efficient way to increase both private and social benefits of incurring the cost of implementing IT.  相似文献   
155.
Scott Barclay 《Law & policy》1999,21(4):427-443
In this article, I argue that litigants identify the appellate courts as offering a powerful and public arena where litigants' claims are placed (at least temporarily) on an equal footing with the current state of the law. In this context, the initiation of appeals is treated as synonymous with receiving endorsements from the appellate courts that the litigants' original claims had sufficient merit to deserve better treatment than they had received previously from either the opposing parties or the trial courts. These actions work to raise appellants' social status, and I propose that such activity is one additional reason why some litigants might appeal.  相似文献   
156.
157.
158.
159.
160.
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