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   554篇
  免费   5篇
管理学   87篇
民族学   3篇
人口学   48篇
丛书文集   5篇
理论方法论   47篇
综合类   1篇
社会学   277篇
统计学   91篇
  2020年   7篇
  2019年   8篇
  2018年   12篇
  2017年   10篇
  2016年   5篇
  2014年   13篇
  2013年   70篇
  2012年   17篇
  2011年   18篇
  2010年   18篇
  2009年   8篇
  2008年   17篇
  2007年   19篇
  2006年   13篇
  2005年   12篇
  2004年   12篇
  2003年   15篇
  2002年   20篇
  2001年   15篇
  2000年   13篇
  1999年   16篇
  1998年   11篇
  1997年   6篇
  1996年   7篇
  1995年   6篇
  1994年   11篇
  1993年   12篇
  1992年   13篇
  1991年   19篇
  1990年   6篇
  1989年   4篇
  1988年   7篇
  1987年   7篇
  1986年   4篇
  1985年   9篇
  1984年   7篇
  1983年   10篇
  1982年   9篇
  1981年   8篇
  1980年   5篇
  1979年   5篇
  1978年   6篇
  1977年   4篇
  1976年   8篇
  1975年   8篇
  1974年   4篇
  1973年   5篇
  1971年   2篇
  1969年   4篇
  1968年   3篇
排序方式: 共有559条查询结果,搜索用时 140 毫秒
41.
42.
Adaptive sampling without replacement of clusters   总被引:1,自引:0,他引:1  
In a common form of adaptive cluster sampling, an initial sample of units is selected by random sampling without replacement and, whenever the observed value of the unit is sufficiently high, its neighboring units are added to the sample, with the process of adding neighbors repeated if any of the added units are also high valued. In this way, an initial selection of a high-valued unit results in the addition of the entire network of surrounding high-valued units and some low-valued “edge” units where sampling stops. Repeat selections can occur when more than one initially selected unit is in the same network or when an edge unit is shared by more than one added network. Adaptive sampling without replacement of networks avoids some of this repeat selection by sequentially selecting initial sample units only from the part of the population not already in any selected network. The design proposed in this paper carries this step further by selecting initial units only from the population, exclusive of any previously selected networks or edge units.  相似文献   
43.
Circular data arise in many contexts, a particularly rich source being animal orientation experiments. Often, in the analysis of such data, a fundamental question of scientific interest is whether the underlying distribution is reflectively symmetric about some specific axis. In this paper, the situation in which the axis of interest is known to be a median axis is considered and a simple, asymptotically distribution- free test for circular reflective symmetry against skew alternatives is developed. The results from a simulation study lead to a testing strategy incorporating the new test and the circular analogue of the modified runs test of Modarres & Gastwirth (1996). The application of the testing strategy is illustrated using circular data arising from two animal orientation experiments.  相似文献   
44.
45.
The public library system is targeting the geriatric population and instituting programs to meet informational and recreational needs. From retirement planning, visual aids, and screening, to accessing library material to the elderly, the public library system attempts to meet the challenge of providing service to this special population. Although not a formal group, the library has inherent therapeutic effects that benefit the elderly who participate in their programs. The clinician would be advised to take advantage of these various programs. Because each local and regional center will offer different programs, calling a local library is the most effective way to find out what a specific public library system has to offer. Nurses may also consider joint efforts to initiate programs in their library systems to better meet the population's needs.  相似文献   
46.
公共行政是正义研究的重要领域。传统理论多采用罗尔斯、诺齐克和沃尔泽等人为正义提供的客观标准。但这些标准不仅在理论上相互冲突,而且在公共行政的实践中也常常会导致模棱两可的判断。本研究旨在提出一种符号正义的观念,来指导当代公共行政的理论与实践。这种观念认为正义并不存在中立客观的标准,而是被群体共享的信念和实践所建构。研究者只有将正义置于特定语言游戏的背景中,才能真正理解其发生和运作。因为和正义相关的不同语言游戏之间只存在家族相似性,所以公共行政必须面对相互冲突的复杂环境。符号正义的观念能够为这种公共行政问题的复杂性提供必不可少的分析框架。  相似文献   
47.
48.
The author addresses the problem of testing circular data for reflective symmetry about an unknown central direction and proposes a simple omnibus test based on the sample second sine moment about an estimation of this direction. Under quite general conditions, for an underlying distribution which is reflectively symmetric, the large‐sample asymptotic distribution of the test statistic is standard normal. Randomization and bootstrap variants of the test are also introduced, and the operating characteristics of different versions of the test are investigated in a Monte Carlo study. The large‐sample and bootstrap versions of the test are applied in the analysis of two illustrative examples drawn from the circular statistics literature.  相似文献   
49.
North American problems in coming to terms with the management of the semi-arid Plains environment are well known. Less documented are those of Argentina's equivalent on the fringe of the Humid Pampas. Argentine agricultural aid and research has been focussed on the Humid Pampas, and little understanding of the special problems of the dry zone is apparent. Issues of production and conservation are in urgent need of attention. In addition to the limits posed by the natural environment, a number of human factors affect the ability of ranchers to produce from the dry lands. In a field study of the Caldenal, some indications are that the factors are different from other environments in Latin America. Large properties are not less productive per hectare than small, and standard technology does not guarantee good results from ranching. Tenant farming is not a problem, but there is an impoverished group, those ranchers without other means of earning a livelihood. A recommendation is for encouragement to be given to larger ranch units, and for more research into relevant technology, which is likely to include conservationist measures, whose introduction to the ranches should be financially supported.  相似文献   
50.
The profession's present role in day care is assessed through a review of the social work literature. This analysis suggests that the profession is not systematically involved enough in child care systems on a local or national basis. The author discusses why this is so, and suggests professional points of access for social workers interested in providing social services in different types of child care. In addition, it is recommended that more policy and programmatic emphases be put on providing social services to family day care homes, the care of children by their relatives, and for centers that serve ethnic minorities and disadvantaged families.I wish to thank Beatrice Saunders and Eleanor Brilliant for their help in writing this article.  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