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   15819篇
  免费   1336篇
各国政治   551篇
工人农民   576篇
世界政治   1125篇
外交国际关系   457篇
法律   11654篇
中国共产党   1篇
中国政治   104篇
政治理论   2591篇
综合类   96篇
  2020年   380篇
  2019年   407篇
  2018年   472篇
  2017年   521篇
  2016年   557篇
  2015年   483篇
  2014年   494篇
  2013年   1556篇
  2012年   374篇
  2011年   481篇
  2010年   601篇
  2009年   592篇
  2008年   381篇
  2007年   354篇
  2006年   465篇
  2005年   312篇
  2004年   318篇
  2003年   322篇
  2002年   282篇
  2001年   605篇
  2000年   529篇
  1999年   424篇
  1998年   200篇
  1997年   184篇
  1996年   154篇
  1995年   178篇
  1994年   198篇
  1993年   162篇
  1992年   312篇
  1991年   322篇
  1990年   332篇
  1989年   338篇
  1988年   331篇
  1987年   295篇
  1986年   294篇
  1985年   314篇
  1984年   287篇
  1983年   250篇
  1982年   196篇
  1981年   172篇
  1980年   163篇
  1979年   195篇
  1978年   125篇
  1977年   100篇
  1976年   97篇
  1975年   94篇
  1974年   113篇
  1973年   90篇
  1972年   77篇
  1971年   75篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
Andrew M. Greeley is a priest, sociologist, novelist, and journalist. His scholarly writings concentrate on religion and ethnicity. His other writings range from critiques of the Catholic church to best-selling novels.  相似文献   
103.
This paper describes a collaborative exercise intended to demonstrate whether uniformity of DNA profile results could be achieved between different European laboratories. It was shown that this goal can be obtained provided that a common protocol is followed (specifically the use of a common electrophoretic buffer as being the most important parameter). Generally, lower molecular weight loci (with lower molecular weight fragments) such as YNH24 perform better than higher molecular weight loci such as MS43a. The results of the exercise are discussed in relation to the objectives of the European DNA profiling group (EDNAP).  相似文献   
104.
The authors examine the characteristics of threatening and otherwise inappropriate communications sent to members of the U.S. Congress by a sample of 86 subjects, 20 of whom threatened assassination. We quote excerpts from these letters and provide quantitative data on such variables as the volume, duration, form, and appearance of such communications; the enclosures; the subjects' perceived relationships to the recipients; the thematic content of the communications; and the messages and threats communicated. Comparisons between 43 subjects who pursued encounters with members of Congress and 43 who did not revealed 17 factors associated with such pursuit. In this population, threateners were significantly less likely to pursue an encounter than inappropriate letter writers who did not threaten, regardless of the type of threat or the harm threatened. Inappropriate letters to members of Congress are compared with those directed to Hollywood celebrities. Mentally disordered persons writing to public figures often mention and sometimes threaten public figures other than those to whom the letters are addressed, which raises important issues regarding notification of endangered third parties and the sharing of information among protective agencies.  相似文献   
105.
In the forensic science laboratory, the recovery of spermatozoa from vaginal swabs, or vaginal cells from penile swabs, can help determine if sexual intercourse may have taken place. There are several methods used to recover spermatozoa and cells from the swabs before visualisation on a microscope slide and most of these methods use water. Phosphate buffered saline (PBS) is a non-toxic solution used in many biological laboratories. Unlike water, PBS prevents cells rupturing or shrivelling up due to osmosis. This study demonstrates that PBS can be used for the extraction of spermatozoa and cells from swabs and that PBS does not affect subsequent DNA profiling.  相似文献   
106.
Bioaerosol data is often used in cases of building mold infestation alleging damage or adverse health effects upon occupants, despite the lack of consistent sampling and analytical protocols and numerical health-based standards. The most fundamental problem in these scenarios is defining a “significant” difference between a suspect indoor environment and the reference environment, regardless of the type of sampling and analysis utilized. Data interpretation focused upon differences in absolute numerical concentrations of fungi is subject to wide differences in expert opinion. On the other hand, an objective quantification of differences can be expressed in terms of probability and better meets criteria established in evidentiary rules.  相似文献   
107.
Der Begriff der Landeskultur umfasst alle Maßnahmen zur Verbesserung der land- und forstwirtschaftlichen Nutzung des Bodens einschließlich der Erhaltung der Kulturlandschaft. Landeskultur ist somit alles Planen und Handeln mit dem Ziel, die Umwelt als gegebenes Naturraumpotential, insbesondere Wasser, Boden, Luft und die dazugehörigen Natur-, Kultur- und Sachgüter optimal zu erhalten, gestalten und rationell zu nutzen sowie dieses Potential mit bestmöglicher Qualität als natürliche und kulturelle Lebensgrundlage für die Allgemeinheit nachhaltig zu sichern. Landeskultur dient somit auch der Belebung und Werterhöhung der gebauten und gepflanzten Umwelt. Dies schließt auch und gerade die kulturelle Seite einschließlich Kulturlandschaften mit ein. Dabei ist es bis zur Überprüfung durch das BVerfG noch hinnehmbar, dass der Begriff „Landeskultur“ in Art. 89 Abs. 3 GG wegen der Mischkompetenz von Bund und Land vom BVerwG enger ausgelegt wird als in anderen Rechtsvorschriften.  相似文献   
108.
109.
Washington University v. Catalona revolves around ownership of tissue samples provided by patients for research purposes, raising significant ethical and legal questions concerning patient rights, current human research practices, and the treatment of samples as capital resources by the research institution.  相似文献   
110.
Here we consider two ways that nanomedicine might be disruptive. First, low-end disruptions that are intrinsically unpredictable but limited in scope, and second, high end disruptions that involve broader societal issues but can be anticipated, allowing opportunity for ethical reflection.  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