全文获取类型
收费全文 | 8214篇 |
免费 | 145篇 |
国内免费 | 1篇 |
专业分类
管理学 | 1166篇 |
民族学 | 36篇 |
人口学 | 806篇 |
丛书文集 | 34篇 |
理论方法论 | 728篇 |
综合类 | 103篇 |
社会学 | 3907篇 |
统计学 | 1580篇 |
出版年
2023年 | 44篇 |
2021年 | 44篇 |
2020年 | 121篇 |
2019年 | 176篇 |
2018年 | 219篇 |
2017年 | 291篇 |
2016年 | 219篇 |
2015年 | 148篇 |
2014年 | 197篇 |
2013年 | 1407篇 |
2012年 | 279篇 |
2011年 | 245篇 |
2010年 | 172篇 |
2009年 | 161篇 |
2008年 | 191篇 |
2007年 | 171篇 |
2006年 | 193篇 |
2005年 | 180篇 |
2004年 | 177篇 |
2003年 | 157篇 |
2002年 | 174篇 |
2001年 | 177篇 |
2000年 | 180篇 |
1999年 | 185篇 |
1998年 | 140篇 |
1997年 | 140篇 |
1996年 | 131篇 |
1995年 | 115篇 |
1994年 | 109篇 |
1993年 | 114篇 |
1992年 | 117篇 |
1991年 | 129篇 |
1990年 | 128篇 |
1989年 | 144篇 |
1988年 | 88篇 |
1987年 | 111篇 |
1986年 | 95篇 |
1985年 | 117篇 |
1984年 | 101篇 |
1983年 | 106篇 |
1982年 | 80篇 |
1981年 | 81篇 |
1980年 | 77篇 |
1979年 | 82篇 |
1978年 | 83篇 |
1977年 | 60篇 |
1976年 | 66篇 |
1975年 | 61篇 |
1974年 | 62篇 |
1973年 | 48篇 |
排序方式: 共有8360条查询结果,搜索用时 23 毫秒
131.
132.
The administration of higher education, as with other administrative environments, has become increasingly complex. This paper presents a mathematical model which addresses one of the administrative tasks concerning administrators in all institutions, the establishment of faculty teaching schedules. The assignment technique utilized by the model is linear programming with two special characteristics: goal programming and mixed-integer programming. The goal programming characteristic refers to the provision of explicit stack variables to take on values representing deviations from assignment criteria that may result in resolving conflicts which arise from interactive administrative priorities. The mixed-integer programming characteristic refers to a requirement of the model that certain variables take on only integer values if they appear in the final solution. The model is demonstrated using two different sets of preference orderings for goal achievement. 相似文献
133.
Examining Localized Patterns of Air Quality Perception in Texas: A Spatial and Statistical Analysis 总被引:1,自引:0,他引:1
Environmental and human health issues associated with outdoor air pollution, such as ozone, sulfur dioxide, and other pollutants in metropolitan regions, are an area of growing concern for both policy officials and the general public. Increasing attention from the news media, new health data, and public debate over the effectiveness of clean air regulations have raised the importance of air quality in the public consciousness. While public perceptions of air quality have been studied thoroughly dating back to the 1960s, little empirical research has been conducted to explain the spatial aspects of these perceptions, particularly at the local level. Although recent studies suggest characteristics of local setting are important in shaping perceptions of air quality, the roles of proximity, neighborhood characteristics, and location have not been clarified. This study seeks to improve understanding of the major factors shaping public perceptions of air quality by examining the spatial pattern of local risk perception, the role of socioeconomic characteristics in forming these perceptions, and the relationship between perceived and scientifically measured air pollution. First, we map the spatial pattern of local air quality perceptions using Geographic Information Systems (GIS) across the Dallas and Houston metropolitan areas. Next, we explain these perceptions through local contextual factors using both bivariate correlations and multivariate regression analysis. Results indicate that perceptions of air quality in the study areas are not significantly correlated with air quality based on readings of air monitoring stations. Instead, perceptions appear to be influenced by setting (urban vs. rural), state identification, access to information, and socioeconomic characteristics such as age, race, and political identification. We discuss the implications of the findings and provide direction on how further research can provide a deeper understanding of the local contextual factors influencing public perceptions. 相似文献
134.
It is shown that the uncertainty connected with a `random in a broad sense' (not necessarily stochastic) event always has some `statistical regularity' (SR) in the form of a family of finite-additive probability distributions. The specific principle of guaranteed result in decision making is introduced. It is shown that observing this principle of guaranteed result leads to determine the one optimality criterion corresponding to a decision system with a given `statistical regularity'. 相似文献
135.
Unmet need for family planning has been a core concept in international population discourse for several decades. This article reviews the history of unmet need and the development of increasingly refined methods of its empirical measurement and delineates the main questions that have been raised about unmet need during the past decade, some of which concern the validity of the concept and others its role in policy debates. The discussion draws heavily on empirical research conducted during the 1990s, much of it localized, in‐depth studies combining quantitative and qualitative methodologies. Of the causes of unmet need other than those related to access to services, three emerge as especially salient: lack of necessary knowledge about contraceptive methods, social opposition to their use, and health concerns about possible side effects. The article argues that the concept of unmet need for family planning, by joining together contraceptive behavior and fertility preferences, encourages an integration of family planning programs and broader development approaches to population policy. By focusing on the fulfillment of individual aspirations, unmet need remains a defensible rationale for the formulation of population policy and a sensible guide to the design of family planning programs. 相似文献
136.
137.
138.
Rehousing of elderly people in Australia has generally not been preceded by research into the kind of assistance that is necessary. An example is given of how an attempt was made to discover the needs of the elderly disabled in a small country community. Assessment by observation of people at home revealed the need for assistance for them to stay where they were. Home Care organized from the district hospital is often a more appropriate answer to this problem than the building of expensive and unnecessary institutions. 相似文献
139.
B. F. J. Manly 《Researches on Population Ecology》1973,14(2):151-158
Summary An equation is given for the estimation of selective values from data obtained by mark-recapture experiments, assuming that
selective pressures remain constant while the experiments are carried out. The equation does not have an explicit solution
but can readily be solved using a trial-and-error method.
The use of the equation is illustrated on some data reported byKettlewell
et al. (1969) from an experiment involvingtypica andedda morphs of the mothAmathes glareosa. It is found that theedda morph apparently had a selective advantage of about 12% per day compared to thetypica morph and that this is significantly different from zero. Using another methodKettlewell concluded that the selective advantage of theedda morph was only 7% and that this was not statistically significant. 相似文献
140.