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   18001篇
  免费   1386篇
各国政治   636篇
工人农民   604篇
世界政治   1323篇
外交国际关系   495篇
法律   13103篇
中国共产党   1篇
中国政治   128篇
政治理论   2989篇
综合类   108篇
  2020年   398篇
  2019年   435篇
  2018年   491篇
  2017年   578篇
  2016年   606篇
  2015年   514篇
  2014年   549篇
  2013年   1777篇
  2012年   421篇
  2011年   523篇
  2010年   649篇
  2009年   609篇
  2008年   440篇
  2007年   449篇
  2006年   546篇
  2005年   405篇
  2004年   389篇
  2003年   410篇
  2002年   360篇
  2001年   707篇
  2000年   600篇
  1999年   487篇
  1998年   224篇
  1997年   194篇
  1996年   177篇
  1995年   196篇
  1994年   209篇
  1993年   174篇
  1992年   346篇
  1991年   361篇
  1990年   336篇
  1989年   372篇
  1988年   328篇
  1987年   313篇
  1986年   320篇
  1985年   348篇
  1984年   319篇
  1983年   310篇
  1982年   232篇
  1981年   211篇
  1980年   187篇
  1979年   236篇
  1978年   165篇
  1977年   141篇
  1976年   119篇
  1975年   113篇
  1974年   132篇
  1973年   120篇
  1972年   93篇
  1971年   103篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
Sixteen major evaluations of programs to prevent school bullying, conducted in 11 different countries, are reviewed in detail. Of these 16 evaluations, 8 produced desirable results, 2 produced mixed results, 4 produced small or negligible effects, and 2 produced undesirable results. These varying findings may reflect variations in programs, in implementation, in assessment methods, or in evaluation designs. It is concluded that high-quality evaluations are needed in the future, with randomized designs, theoretically grounded interventions, multiple measures of bullying, and attempts to disentangle the effectiveness of different program components.  相似文献   
122.
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   
123.
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   
124.
A 6-month-old girl died suddenly without any previous symptoms of heart failure. Autopsy examination showed cardiomegaly (97 g) with a severely fibrotized myocardium. The left coronary artery was originating from the pulmonary artery. Histologically, the myocardium showed myocardial infarcts of different ages, as well as grossly thickened arterial branches due to increased flow in left-right shunt. We suggest that rare anomalies of the coronary arteries should be considered in the autopsies of suspected sudden infant death syndrome cases.  相似文献   
125.
The impact of high temperatures (24 to 39 degrees C) and low to moderately high humidities (20 to 70%) on the applicability of TLC systems for drug identification was studied during a 6 month climatologic cycle in Burkina Faso (West Africa). In general, the Rf values as observed on the plates were found to be substantially affected as compared with values obtained at temperate climates. Some TLC systems were more affected than others and the largest deviations of up to 30 Rf units were at low humidities. Tropical conditions also had a negative effect on the reproducibility of Rf values. However, when an Rf-correction procedure was applied, using reference mixtures of known drugs on each plate, accuracy as well as reproducibility of the resulting Rfc values were drastically improved and data thus corrected were found to be compatible with existing TLC data bases developed under moderate climatological conditions. The impact of high to extremely high humidities (70 to 100%) remains to be investigated.  相似文献   
126.
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   
127.
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   
128.
Following the tradition of Joan McCord's work, this paper reviews longitudinal-experimental studies in criminology with community samples of at least 100 persons, follow-up periods of at least 5 years, personal interviews, and measures of offending. The main advantages of such studies are in investigating both the natural history of development (including the effects of risk/protective factors and life events) and the impact of interventions on offending. This paper also reviews advantages and problems of prospective longitudinal surveys, randomized experiments, and longitudinal-experimental studies in criminology. Four key longitudinal-experimental studies were conducted by Joan McCord, Richard Tremblay, Lawrence Schweinhart and David Olds. Other studies have been conducted, or are currently under way, but no criminological study has yet been published with several years of personal data on participants both before and after an intervention.Joan McCord Award Lecture given at the American Society of Criminology, Toronto, Canada.  相似文献   
129.
This synoptic article focuses on the origin and functioning of the Office of the Family Advocate as the protector of the interests of minor children in divorce cases. Attention is paid to the general contemporary trend to specialise in judicial decision-making that developed out of an increasing need for expertise in the administration of justice. A number of arguments for and against judicial specialisation are addressed. The origin of the Office of the Family Advocate within the South African judicial system is discussed and a brief exposition of the history of divorce legislation in South Africa is given. This is followed by attention to the functioning of the Office of the Family Advocate with reference to the process followed in investigations of this office and points of criticism against the system are highlighted. The article closes with an indication of the need for research in this regard and possible focus points for future research are identified.  相似文献   
130.
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