全文获取类型
收费全文 | 7904篇 |
免费 | 158篇 |
专业分类
管理学 | 1187篇 |
民族学 | 27篇 |
人口学 | 765篇 |
丛书文集 | 26篇 |
理论方法论 | 592篇 |
综合类 | 105篇 |
社会学 | 3371篇 |
统计学 | 1989篇 |
出版年
2020年 | 117篇 |
2019年 | 151篇 |
2018年 | 217篇 |
2017年 | 272篇 |
2016年 | 189篇 |
2015年 | 131篇 |
2014年 | 190篇 |
2013年 | 1315篇 |
2012年 | 258篇 |
2011年 | 241篇 |
2010年 | 178篇 |
2009年 | 170篇 |
2008年 | 145篇 |
2007年 | 183篇 |
2006年 | 160篇 |
2005年 | 161篇 |
2004年 | 146篇 |
2003年 | 143篇 |
2002年 | 149篇 |
2001年 | 197篇 |
2000年 | 189篇 |
1999年 | 172篇 |
1998年 | 129篇 |
1997年 | 126篇 |
1996年 | 126篇 |
1995年 | 106篇 |
1994年 | 104篇 |
1993年 | 97篇 |
1992年 | 140篇 |
1991年 | 119篇 |
1990年 | 116篇 |
1989年 | 111篇 |
1988年 | 96篇 |
1987年 | 90篇 |
1986年 | 95篇 |
1985年 | 107篇 |
1984年 | 112篇 |
1983年 | 123篇 |
1982年 | 98篇 |
1981年 | 88篇 |
1980年 | 85篇 |
1979年 | 94篇 |
1978年 | 90篇 |
1977年 | 80篇 |
1976年 | 67篇 |
1975年 | 67篇 |
1974年 | 58篇 |
1973年 | 58篇 |
1972年 | 41篇 |
1971年 | 49篇 |
排序方式: 共有8062条查询结果,搜索用时 734 毫秒
801.
Mei-Ling Ting Lee G.A. Whitmore Francine Laden Jaime E. Hart Eric Garshick 《Journal of statistical planning and inference》2009
A case–control study of lung cancer mortality in U.S. railroad workers in jobs with and without diesel exhaust exposure is reanalyzed using a new threshold regression methodology. The study included 1256 workers who died of lung cancer and 2385 controls who died primarily of circulatory system diseases. Diesel exhaust exposure was assessed using railroad job history from the US Railroad Retirement Board and an industrial hygiene survey. Smoking habits were available from next-of-kin and potential asbestos exposure was assessed by job history review. The new analysis reassesses lung cancer mortality and examines circulatory system disease mortality. Jobs with regular exposure to diesel exhaust had a survival pattern characterized by an initial delay in mortality, followed by a rapid deterioration of health prior to death. The pattern is seen in subjects dying of lung cancer, circulatory system diseases, and other causes. The unique pattern is illustrated using a new type of Kaplan–Meier survival plot in which the time scale represents a measure of disease progression rather than calendar time. The disease progression scale accounts for a healthy-worker effect when describing the effects of cumulative exposures on mortality. 相似文献
802.
An inverse regression approach to analyzing quantal response assays with one quanritative independent- variable and any number of qualitative independent variables is presented. A general factorial model ror LQC- inverted relationship and methods of testing hypotheses estimating qulitative Interest are developed. This naper provides a modified method of analysis which is easier to apply than previously existing methods. 相似文献
803.
804.
G. Bowden Templeton Sheryl B. Lash Virginia Robinson Jerry Gale 《Marriage & Family Review》2013,49(1):52-80
ABSTRACT The purpose of this qualitative study was to explore the social networks of Appalachian adolescents to understand socialization strategies and goals. A total of 46 interviews were conducted with five families (mothers, fathers, and adolescents) and 11 socialization agents the families identified as exerting significant influence in the lives of the adolescents. Interviews were transcribed and then analyzed using principles of grounded theory. Five themes developed from the interviews: the importance of community to the socialization process, adult involvement and support, adolescent monitoring, teaching respect and responsibility, and adolescent autonomy. Results suggest the need for in-depth investigation of adolescent development within a variety of cultural and social contexts to more fully understand these processes. 相似文献
805.
In this paper, we consider noninformative priors for the ratio of variances in two normal populations. We develop first and
second order matching priors. We find that the second order matching prior matches alternative coverage probabilities up to
the second order and is also a HPD matching prior. It turns out that among the reference priors, only one-at-a-time reference
prior satisfies a second order matching criterion. Our simulation study indicates that the one-at-a-time reference prior performs
better than other reference priors in terms of matching the target coverage probabilities in a frequentist sense.
This work is supported by Korea Research Foundation Grant (KRF-2004-002-C00041). 相似文献
806.
807.
The concept of exposure is central to chemical risk assessment and plays an important role in communicating to the public about the potential health risks of chemicals. Research on chemical risk perception has found some indication that the model lay people use to judge chemical exposure differs from that of toxicologists, thereby leading to different conclusions about chemical safety. This paper presents the results of a series of studies directed toward developing a model for understanding how lay people interpret the concept of chemical exposure. The results indicate that people's beliefs about chemical exposure (and its risks) are based on two broad categories of inferences. One category of inferences relates to the nature in which contact with a chemical has taken place, including the amount of a chemical involved and its potential health consequences. A second category of inferences about chemical exposure relates to the pragmatics of language interpretation, leading to beliefs about the motives and purposes behind chemical risk communication. Risk communicators are encouraged to consider how alternative models of exposure and language interpretation can lead to conflicting conclusions on the part of the public about chemical safety. 相似文献
808.
Toon W. Taris Paul J. G. Schreurs Ingrid J. Van Iersel-Van Silfhout 《Work and stress》2001,15(4):283-296
This study examined the antecedents of job strain (emotional exhaustion, health complaints) and withdrawal behaviour (e.g. lowered organizational commitment) among a cross-sectional sample of 131 academic staff members of the law department of a large Dutch university. Conservation of resources theory (Hobfoll, 1989) provided the theoretical background for this study. Strains and withdrawal behaviours were expected to be most prominent among those who reported having few resources and/or who reported high job demands. Structural equation modelling revealed that this was indeed the case. As predicted, differential patterns of effects emerged for job demands and job resources. Analysis of the effects of four job-specific stressors revealed that especially the structural aspects of a staff member's teaching task (e.g. the number of students in their classes) contributed strongly to perceived job demands. Theoretical and practical implications of the study are discussed. 相似文献
809.
A. G. Watts 《The Career development quarterly》2000,48(4):301-312
The rationale for policy interest in career development services and the way in which this rationale is being strengthened by the current transformations in work and career are discussed. The potential roles of public policy in relation to career development services are explored, along with ways in which such services can influence the policy‐making process. A range of policy issues related to making career development services available to all throughout life are identified. Stronger structures and processes are needed to bring together career development practitioners with policy makers and other stakeholder interests in order to address tasks of common concern. 相似文献
810.
Confidence intervals for parameters that can be arbitrarily close to being unidentified are unbounded with positive probability [e.g. Dufour, J.-M., 1997. Some impossibility theorems in econometrics with applications to instrumental variables and dynamic models. Econometrica 65, 1365–1388; Pfanzagl, J. 1998. The nonexistence of confidence sets for discontinuous functionals. Journal of Statistical Planning and Inference 75, 9–20], and the asymptotic risks of their estimators are unbounded [Pötscher, B.M., 2002. Lower risk bounds and properties of confidence sets for ill-posed estimation problems with applications to spectral density and persistence estimation, unit roots, and estimation of long memory parameters. Econometrica 70, 1035–1065]. We extend these “impossibility results” and show that all tests of size α concerning parameters that can be arbitrarily close to being unidentified have power that can be as small as α for any sample size even if the null and the alternative hypotheses are not adjacent. The results are proved for a very general framework that contains commonly used models. 相似文献