全文获取类型
收费全文 | 8844篇 |
免费 | 168篇 |
专业分类
管理学 | 1233篇 |
民族学 | 58篇 |
人才学 | 1篇 |
人口学 | 863篇 |
丛书文集 | 51篇 |
教育普及 | 1篇 |
理论方法论 | 838篇 |
综合类 | 81篇 |
社会学 | 4292篇 |
统计学 | 1594篇 |
出版年
2023年 | 51篇 |
2021年 | 72篇 |
2020年 | 144篇 |
2019年 | 196篇 |
2018年 | 212篇 |
2017年 | 293篇 |
2016年 | 233篇 |
2015年 | 162篇 |
2014年 | 215篇 |
2013年 | 1479篇 |
2012年 | 251篇 |
2011年 | 255篇 |
2010年 | 222篇 |
2009年 | 185篇 |
2008年 | 256篇 |
2007年 | 246篇 |
2006年 | 224篇 |
2005年 | 205篇 |
2004年 | 198篇 |
2003年 | 161篇 |
2002年 | 216篇 |
2001年 | 211篇 |
2000年 | 207篇 |
1999年 | 198篇 |
1998年 | 160篇 |
1997年 | 143篇 |
1996年 | 139篇 |
1995年 | 129篇 |
1994年 | 113篇 |
1993年 | 135篇 |
1992年 | 132篇 |
1991年 | 147篇 |
1990年 | 122篇 |
1989年 | 119篇 |
1988年 | 119篇 |
1987年 | 123篇 |
1986年 | 87篇 |
1985年 | 115篇 |
1984年 | 109篇 |
1983年 | 125篇 |
1982年 | 76篇 |
1981年 | 74篇 |
1980年 | 65篇 |
1979年 | 82篇 |
1978年 | 77篇 |
1977年 | 62篇 |
1976年 | 68篇 |
1975年 | 60篇 |
1974年 | 58篇 |
1973年 | 46篇 |
排序方式: 共有9012条查询结果,搜索用时 31 毫秒
11.
12.
13.
D R Lairson R Harrist D W Martin R Ramby T A Rustin J M Swint K Harlow J Cobb 《Journal of drug education》1992,22(4):337-352
Primary care physicians are well situated to identify patients with substance abuse problems and motivate them to seek appropriate assistance, but active programs are the exception. A study in a community setting was undertaken to assess the CAGE (the first letters of key words in a series of four questions about drinking: cut down; annoyed; guilty; and eye-opener), instrument in the routine screening for alcohol problems in both new and established patients. The screening process identified subjects for a pilot evaluation of a motivational interview designed to encourage problem-solving behavior. This article focuses on the screening results and the use of the CAGE instrument. During June and July of 1990, 687 patients of two primary care physicians belonging to a large group practice were asked to complete a health questionnaire that included the CAGE. Those who responded affirmatively to at least two of the four CAGE questions were requested to participate in follow-up assessment of problems associated with alcohol and health. The type and severity of alcohol problems experienced by patients who scored positive on the CAGE are described. Prevalence of a positive score on the CAGE was 8.6 percent with males, smokers, and blue collar and unemployed persons being more likely to score positive. The positive predictive value was .68. Primarily, persons with moderate alcohol problems were identified. Results show that the CAGE instrument is a useful screening device for identifying those with mild to moderate substance abuse problems, increasing the opportunity for intervention prior to serious medical complications. The instrument is easily administered, and has demonstrated relatively high levels of sensitivity and specificity. When combined with assessment and motivational interviews, the CAGE shows promise in the secondary prevention of substance abuse and related health problems. 相似文献
14.
Suzanne T. Ortega David R. Johnson Peter G. Beeson Betty J. Craft 《Rural sociology》1994,59(4):598-619
Abstract This paper examines rural/urban differences and trends in mental health during the farm crisis of the 1980s in a large panel sample from a midwestern state. A community research perspective, which attributes differences to life styles, culture, and community context, is contrasted with an economic stress perspective, which focuses on individual differences in economic circumstances as determinants of rural-urban differences in mental health. Survey samples from 1981, 1986, and 1989 are used to examine differences among seven categories of community type. Multiple regression analysis of the trend and panel data provide support for both the individual economic distress and community context models. 相似文献
15.
Emmanuelle Cam Bernard Cadiou James E. Hines Jean Yves Monnat 《Journal of applied statistics》2002,29(1):163-185
Many studies have provided evidence that, in birds, inexperienced breeders have a lower probability of breeding successfully. This is often explained by lack of skills and knowledge, and sometimes late laying dates in the first breeding attempt. There is growing evidence that in many species with deferred reproduction, some prebreeders attend breeding places, acquire territories and form pairs. Several behavioural tactics assumed to be associated with territory acquisition have been described in different species. These tactics may influence the probability of recruiting in the breeding segment of the population, age of first breeding, and reproductive success in the first breeding attempt. Here we addressed the influence of behaviour ('squatting') during the prebreeding period on demographic parameters (survival and recruitment probability) in a long-lived colonial seabird species: the kittiwake. We also investigated the influence of behaviour on reproductive trajectory. Squatters have a higher survival and recruitment probability, and a higher probability of breeding successfully in the first breeding attempt in all age-classes where this category is represented. The influence of behaviour is mainly expressed in the first reproduction. However, there is a relationship between breeding success in the first occasion and subsequent occasions. The influence of breeding success in the first breeding attempt on the rest of the trajectory may indirectly reflect the influence of behaviour on breeding success in the first occasion. The shape of the reproductive trajectory is influenced by behaviour and age of first breeding. There is substantial individual variation from the mean reproductive trajectory, which is accounted for by heterogeneity in performance among individuals in the first attempt, but there is no evidence of individual heterogeneity in the rate of change over time in performance in subsequent breeding occasions 相似文献
16.
Major policy changes like the 1986 Tax Reform Act (TRA) in the United States provide natural experiments to study attitudinal and behavior responses to law. Surprisingly, public evaluations of the TRA became increasingly negative after passage, while general support for the tax system became more positive in response to the changes. To explain this puzzle, we propose a dynamic model of taxpayer attitudes that is consistent with the observed loose linkage between logically-connected concepts. We briefly review the political context, objectives and impacts of the 1986 Tax Reform Act, and present several studies testing the impact of self-interest, prior beliefs, and social discussion on changes in attitudes and behavior.Results suggest that the complexity of taxes and difficulty in knowing objective impacts weakens the role of self-interest in attitudinal changes, thereby strengthening the role of prior beliefs and discussion. Evaluations of tax laws are most responsive to more politically-oriented influences. 相似文献
17.
Abstract It is well recognized that the informal economy—unregulated economic activities that generate real or in-kind income—features prominently in the day-to-day lives of many in the developing world. Researchers have begun to explore the informal economy in developed countries but this work has focussed primarily on urban areas to the neglect of rural areas. In this paper the nature and correlates of informal work in nonmetropolitan Pennsylvania are described through an analysis of survey data on 505 families. Results indicate that participation in informal activities is widespread, is not more typical of the poor, does not contribute greatly to family income on average but does help many poor families weather difficult economic times, is both economically and noneconomically motivated, and, net of other sociodemographic variables, is positively related to rurality of residence and formal labor supply. 相似文献
18.
We propose some estimators of noncentrality parameters which improve upon usual unbiased estimators under quadratic loss. The distributions we consider are the noncentral chi-square and the noncentral F. However, we give more general results for the family of elliptically contoured distributions and propose a robust dominating estimator. 相似文献
19.
20.
Barnacle geese ( Branta leucopsis ) make annual migrations between breeding colonies in northern Europe and Eurasia to wintering grounds in Holland. During the migration, they sojourn for several weeks in five areas on the northern coast of Germany. Observers traverse these areas during the course of studying the flocks. Previous belief was that there was little exchange of birds among the five areas; however, some banded birds were observed in more than one area indicating that some movement takes place. In this presentation, we estimate the movement rates among the areas using open- and closed-population models. 相似文献