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   269篇
  免费   18篇
各国政治   9篇
工人农民   17篇
世界政治   26篇
外交国际关系   8篇
法律   183篇
中国政治   6篇
政治理论   36篇
综合类   2篇
  2024年   1篇
  2023年   7篇
  2022年   2篇
  2021年   5篇
  2020年   7篇
  2019年   14篇
  2018年   19篇
  2017年   7篇
  2016年   18篇
  2015年   13篇
  2014年   10篇
  2013年   46篇
  2012年   13篇
  2011年   11篇
  2010年   11篇
  2009年   8篇
  2008年   13篇
  2007年   10篇
  2006年   11篇
  2005年   5篇
  2004年   7篇
  2003年   10篇
  2002年   5篇
  2001年   4篇
  2000年   1篇
  1999年   3篇
  1998年   1篇
  1997年   1篇
  1996年   3篇
  1994年   1篇
  1992年   6篇
  1991年   1篇
  1990年   1篇
  1989年   1篇
  1987年   1篇
  1986年   1篇
  1985年   1篇
  1983年   1篇
  1982年   2篇
  1981年   1篇
  1979年   2篇
  1970年   1篇
  1967年   1篇
排序方式: 共有287条查询结果,搜索用时 62 毫秒
11.
The Victorian periodical press offers unique insights into many diverse areas of nineteenth-century experience, and the complex relations between gender, science and culture in particular, yet it has been consistently marginalized as a primary resource in academic study. The Science in the Nineteenth-century Periodical (SciPer) project at the universities of Sheffield and Leeds is creating a new point of access to a wide range of non-specialist periodicals across the century by means of a fully searchable electronic index. By detailing the entire contents of each journal, and not just those articles that have a clear scientific relevance, it becomes clear that science formed a fundamental and integral part of nineteenth-century culture. The electronic index, moreover, will include hypertext cross-reference links that will allow the user to identify a dialogic pattern of encounters between ostensibly diverse articles, rather than only to browse in a simple chronological mode. By adopting this innovative approach, the SciPer database will reveal the manifold intertextual relations between the fictional works of women writers like Elizabeth Gaskell and the scientific articles that often appeared in the pages of the same magazines, and will show that writers of both sexes and across several different genres actively engaged in vibrant interdisciplinary debates concerning scientific issues in a forum provided by the periodical. Although the SciPer database itself is not specifically focused on issues of gender, the index will include several periodicals aimed explicitly at a female readership and, by providing access to titles still rarely utilized in modern scholarship, it will offer further insights into the important contemporary debates about women and science, as well as the more subtle ways, in which gendered imagery was employed within scientific discourse. This article details some critical findings from Punch , The English Womans Domestic Magazine , Cornhill Magazine and the Review of Reviews .  相似文献   
12.
13.
Prior research has identified a vast number of correlates for delinquent behavior during adolescence, yet a considerable number of errors in prediction remain. These errors suggest that behavioral development among a portion of youths is not well understood, with some exhibiting resilience and others a heightened vulnerability to risks. Examining cases that do not confirm prediction outcomes provides an opportunity to achieve a greater understanding of the relationships between risk factors and delinquency, which can be used to improve theoretical explanations of behavior. This study explores the contribution of genetic and environmental factors to differences in individual responses to cumulative risk for delinquency among a sample of adolescent twins (N = 784 pairs, 49 % female) in the National Longitudinal Study of Adolescent Health. The results indicate that additive genetic and unique environmental factors significantly contribute to variation in responses to cumulative risk across 14 risk factors spanning individual, familial, and environmental domains. When analyzed separately, the majority of the difference between vulnerable youths and the overall population was attributed to genetic influences, while differences between resilient youths and the population were primarily attributed to environmental influences. The findings illustrate the importance of examining both genetic and environmental influences in order to enhance explanations of adolescent offending.  相似文献   
14.
15.
Natural resource management policies like the Pacific salmon harvest policy developed by New York State often did not anticipate the extent of social, economic, and ethical concerns that would be generated, largely because the agency concentrated on biological considerations. The number of concerned stakeholders grew in proportion to both the success and failure of the initial policy. Had all participants been equally willing to recognize both the successes and the failures, development of a revised policy through group negotiations may have been possible, resulting in a cooperative mode of decision making. Instead, institutional mechanisms based on legislated process were ultimately the approach chosen for policy revision.  相似文献   
16.
Grassroots environmental activism among Latin America's poor has altered the debate over environmental policy, social welfare, and citizenship. Yet the question remains whether this social mobilization of the poor is part of a larger trend toward broader environmental concerns and democratic political participation, or a shortlived movement susceptible to the same pressures that have dissolved community mobilization in the past. This article compares Brazil with other Latin American and European countries in surveys of environmental awareness, concerns, and reported behavior. It finds that Brazilians residing in the urban periphery link their own local environmental concerns to more global considerations, and that concern for and activism on environmental issues is positively related to wider community involvement.  相似文献   
17.
18.
Detection and correct classification of gasoline is important for both arson and fuel spill investigation. Principal component analysis (PCA) was used to classify premium and regular gasolines from gas chromatography-mass spectrometry (GC-MS) spectral data obtained from gasoline sold in Canada over one calendar year. Depending upon the dataset used for training and tests, around 80-93% of the samples were correctly classified as either premium or regular gasoline using the Mahalanobis distances calculated from the principal components scores. Only 48-62% of the samples were correctly classified when the premium and regular gasoline samples were divided further into their winter/summer sub-groups. Artificial neural networks (ANNs) were trained to recognise premium and regular gasolines from the same GC-MS data. The best-performing ANN correctly identified all samples as either a premium or regular grade. Approximately 97% of the premium and regular samples were correctly classified according to their winter or summer sub-group.  相似文献   
19.
20.
The presence of cocaine in illicit drug samples is still being determined in some laboratories using spot tests and microcrystal tests. Seventeen chemical species were tested using three different spot tests (Wagner, Marquis, and cobalt thiocyanate followed by stannous chloride reactions) and two microcrystal tests (gold chloride and platinic chloride) to determine whether the results could be differentiated from the results of these tests on cocaine. The data obtained indicated that nine of the 17 compounds gave results similar to those from cocaine using the three spot tests, but that the results from microcrystal testing allowed for differentiation of all nine compounds from cocaine.  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