全文获取类型
收费全文 | 14632篇 |
免费 | 233篇 |
国内免费 | 1篇 |
专业分类
管理学 | 1885篇 |
民族学 | 74篇 |
人才学 | 4篇 |
人口学 | 1308篇 |
丛书文集 | 79篇 |
理论方法论 | 1254篇 |
综合类 | 128篇 |
社会学 | 7044篇 |
统计学 | 3090篇 |
出版年
2022年 | 74篇 |
2021年 | 76篇 |
2020年 | 202篇 |
2019年 | 253篇 |
2018年 | 383篇 |
2017年 | 506篇 |
2016年 | 335篇 |
2015年 | 271篇 |
2014年 | 347篇 |
2013年 | 2713篇 |
2012年 | 485篇 |
2011年 | 408篇 |
2010年 | 360篇 |
2009年 | 277篇 |
2008年 | 316篇 |
2007年 | 345篇 |
2006年 | 323篇 |
2005年 | 317篇 |
2004年 | 254篇 |
2003年 | 275篇 |
2002年 | 275篇 |
2001年 | 366篇 |
2000年 | 328篇 |
1999年 | 310篇 |
1998年 | 247篇 |
1997年 | 221篇 |
1996年 | 263篇 |
1995年 | 237篇 |
1994年 | 238篇 |
1993年 | 219篇 |
1992年 | 245篇 |
1991年 | 255篇 |
1990年 | 236篇 |
1989年 | 200篇 |
1988年 | 221篇 |
1987年 | 212篇 |
1986年 | 168篇 |
1985年 | 206篇 |
1984年 | 211篇 |
1983年 | 194篇 |
1982年 | 155篇 |
1981年 | 127篇 |
1980年 | 125篇 |
1979年 | 143篇 |
1978年 | 125篇 |
1977年 | 99篇 |
1976年 | 81篇 |
1975年 | 84篇 |
1974年 | 91篇 |
1973年 | 68篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
In the development of many diseases there are often associated random variables which continuously reflect the progress of a subject towards the final expression of the disease (failure). At any given time these processes, which we call stochastic covariates, may provide information about the current hazard and the remaining time to failure. Likewise, in situations when the specific times of key prior events are not known, such as the time of onset of an occult tumour or the time of infection with HIV-1, it may be possible to identify a stochastic covariate which reveals, indirectly, when the event of interest occurred. The analysis of carcinogenicity trials which involve occult tumours is usually based on the time of death or sacrifice and an indicator of tumour presence for each animal in the experiment. However, the size of an occult tumour observed at the endpoint represents data concerning tumour development which may convey additional information concerning both the tumour incidence rate and the rate of death to which tumour-bearing animals are subject. We develop a stochastic model for tumour growth and suggest different ways in which the effect of this growth on the hazard of failure might be modelled. Using a combined model for tumour growth and additive competing risks of death, we show that if this tumour size information is used, assumptions concerning tumour lethality, the context of observation or multiple sacrifice times are no longer necessary in order to estimate the tumour incidence rate. Parametric estimation based on the method of maximum likelihood is outlined and is applied to simulated data from the combined model. The results of this limited study confirm that use of the stochastic covariate tumour size results in more precise estimation of the incidence rate for occult tumours. 相似文献
42.
William A. Mueller D.M.D. 《Child and Adolescent Social Work Journal》1993,10(5):395-401
Dental caries in children is now recognized as a preventable disease. The use of fluoride and sealants has produced a major reduction in caries prevalence among school aged children in the United States and other countries. A portion of the child population who are educationally and socioeconomically disadvantaged are not fully receiving these benefits. Public policy, insurance and medicaid groups must be made aware of these preventative measures and strategies developed to implement them. 相似文献
43.
This study investigated the gender-specific, self-reported sexual behaviors and attitudes of never-married college students attending a southeastern university in 1973 and 1988. Data were collected by means of a mailed questionnaire that remained essentially unchanged for both years. The authors found that both men and women reported an increase in heterosexual relationships that included sexual intercourse and a decrease in nonsexual relationships with the other gender. The majority of the students perceived themselves as adequately informed about sexuality and satisfied with their relationships, although the proportion of men who reported being satisfied with their relationships declined over the 15 years. The students indicated that sexuality education should focus primarily on information about AIDS and on preparation for marriage. 相似文献
44.
Bivariate probit estimates with partial observability identify the factors influencing the worker’s decision to seek a state
or local government job and the factors influencing the government’s decision to hire particular workers. The estimates routinely
confirm the presence of a local job queue but confirm the presence of a state job queue only when the role of unionization
is explicitly recognized. Our results suggest that the net benefits from local and state government employment are greater
than those from private sector employment. The estimates also indicate that local governments disproportionately hire racial
minorities relative to the local governments’ pool of applicants but indicate no such relationship for state governments.
The authors thank Dale Belman, Jugal Ghorai, and Matt Higgins for help on this and related work. We also thank the referee
and the editor for useful suggestions. 相似文献
45.
46.
A-optimal ran orders are considered in the presence of a linear trend with emphasis on non-orthogonal situations where no trend-free run order can be. A-optimal. Some possibilities for further extension are also briefly indicated. 相似文献
47.
Sharon Klayman Farber M.S.W. 《Clinical Social Work Journal》1991,19(1):95-98
The author responds to the article by Annaclare van Dalen (1989), disputing her statement that there is little in the literature about the emotional consequences of child abuse. The author reviews the pertinent literature, which is abundant. The author disagrees with van Dalen's statement that the child experiences physical abuse outside the body, and with the statement that the child experiences sexual abuse as pleasurable. In addition the author disagrees with van Dalen's sharp differentiation between physical abuse and sexual abuse, and proposes that sexual abuse be regarded as a variant of physical abuse. 相似文献
48.
Melissa S. Waters R. Carter Hill William J. Moore Robert J. Newman 《Journal of Labor Research》1994,15(4):355-372
This paper estimates a simultaneous-equations model with public sector bargaining laws and union membership treated as jointly-determined
variables. The extent of public sector unionization has a significant positive influence on the passage of prolabor bargaining
legislation and bargaining legislation has strong, independent effects on the extent of public sector unionization.
We gratefully acknowledge the research support provided by Minbo Kim and Parisun Chantonahom. 相似文献
49.
Differential participation after recruitment remains a black box in the social-movement and voluntary-association literatures. This paper identifies several dimensions of membership participation in a professional social-movement organization (SMO) with a national membership and analyzes the determinants of differential involvement in these forms. In general, members' ideological beliefs, social and organizational ties, perceptions about their SMO, and communication with SMO officials all predict participation across the various forms. Our findings extend previous work on differential participation in three ways. First, we statistically isolate cultural dimensions of postrecruitment participation and, in so doing, complement recent ethnographic research. Second, our findings suggest that the distinct dimensions of external and internal participation found by Knoke (1988) in a national sample of voluntary associations may not generalize to national SMOs studied individually. Third, our results indicate that models combining ideological and microstructural factors should explain the multiple forms of participation in SMOs lacking these distinct dimensions. 相似文献
50.