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   66917篇
  免费   3276篇
各国政治   4459篇
工人农民   2823篇
世界政治   5967篇
外交国际关系   3780篇
法律   30941篇
中国共产党   9篇
中国政治   747篇
政治理论   20527篇
综合类   940篇
  2021年   407篇
  2020年   1156篇
  2019年   1518篇
  2018年   1651篇
  2017年   1925篇
  2016年   2142篇
  2015年   1816篇
  2014年   2091篇
  2013年   10470篇
  2012年   1561篇
  2011年   1645篇
  2010年   1798篇
  2009年   2044篇
  2008年   1698篇
  2007年   1674篇
  2006年   1830篇
  2005年   1718篇
  2004年   1627篇
  2003年   1417篇
  2002年   1465篇
  2001年   1538篇
  2000年   1348篇
  1999年   1167篇
  1998年   1072篇
  1997年   957篇
  1996年   939篇
  1995年   895篇
  1994年   891篇
  1993年   922篇
  1992年   932篇
  1991年   956篇
  1990年   927篇
  1989年   958篇
  1988年   944篇
  1987年   974篇
  1986年   925篇
  1985年   999篇
  1984年   909篇
  1983年   952篇
  1982年   887篇
  1981年   827篇
  1980年   644篇
  1979年   674篇
  1978年   577篇
  1977年   507篇
  1976年   474篇
  1975年   398篇
  1974年   412篇
  1973年   422篇
  1972年   369篇
排序方式: 共有10000条查询结果,搜索用时 21 毫秒
301.
302.
Good gas chromatography (GC) separation of molecules is essential for clean gas chromatography/mass spectrometry (GC/MS) confirmation of compounds. The trifluoro derivatives of ephedrine (E) and methamphetamine (MA) coelute on dimethyl silicone capillary columns, such as DB-1, which are most commonly used by chromatographers. Methods are described to separate E and MA to aid GC/MS confirmations of methamphetamine, ephedrine, or both E and MA together, whichever may be present in Enzyme Immunoassay (EIA)-analyzed amphetamine-positive urine samples. The use of the heptafluoro derivatives of E and MA on a DB-1 column, or the trifluoro derivatives of E and MA on a DB-17 column, is suggested for good gas chromatographic separation.  相似文献   
303.
The Supreme Court early took note of extralegal, “social science” materials in Muller v. Oregon (1908), and a half-century later made specific reference to social science authorities in the famous footnote 11 of Brown v. Board of Education (1954). Since Brown, much has been written about the Supreme Court's use of social science research evidence, but there has been little systematic study of that use. Those writing on the subject commonly focus on areas of law such as jury size, where social science has been used, and have generally assumed that social science information has been utilized in Supreme Court decisions with increasing regularity. Surprisingly little is known, however, about either the justices' baseline use of social science authorities, or many other aspects of their uses of social science information. The focus here is on the citation of social science research evidence in a sample of 240 criminal cases decided during the 30 years between the Supreme Court's 1958 and 1987 Terms. The resulting portrait contributes to a fuller understanding of the justices' use of social science materials, and may ultimately help promote more effective utilization of social science research evidence in Supreme Court decisions.  相似文献   
304.
305.
306.
307.
308.
309.
The extent to which local life circumstances influence criminal activity has been the focus of much theoretical debate. Although empirical research has been initiated, it remains limited. Herein, we use data on 524 serious offenders from the California Youth Authority for a seven‐year post‐parole period to examine the relationship between changes in local life circumstances and criminal activity. We extend previous research by employing a statistical model that accounts for the joint distribution of violent and nonviolent crime during the late teens and twenties in order to present information on patterns of criminal activity during a newly recognized developmental period of the life course, “emerging adulthood.”  相似文献   
310.
On the basis of the uncertainty management model, we argue here that when people are uncertain about an organization's trustworthiness, they may resolve the question how they should react toward the organization by relying on their perceptions of the organization's procedures. As a consequence, we predicted that the reactions of parents whose child was in a day care center would be strongly influenced by their perceptions of the procedures used by the organization that was responsible for their children's day care when the parents would be uncertain about the organization's trustworthiness. However, when parents would be certain that the organization could be trusted they would be less in need of procedural information, yielding less strong effects of perceived procedure on parents' reactions. The findings of a survey study corroborate this line of reasoning. In the discussion it is argued that these findings suggest that people especially rely on their perceptions of procedures when they are uncertain about important aspects of their lives, such as the trustworthiness of organizations that are responsible for their children's day care.  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