全文获取类型
收费全文 | 14042篇 |
免费 | 364篇 |
国内免费 | 1篇 |
专业分类
管理学 | 1806篇 |
民族学 | 67篇 |
人才学 | 4篇 |
人口学 | 1241篇 |
丛书文集 | 69篇 |
理论方法论 | 1287篇 |
综合类 | 113篇 |
社会学 | 6844篇 |
统计学 | 2976篇 |
出版年
2023年 | 73篇 |
2022年 | 71篇 |
2021年 | 81篇 |
2020年 | 211篇 |
2019年 | 278篇 |
2018年 | 390篇 |
2017年 | 517篇 |
2016年 | 358篇 |
2015年 | 288篇 |
2014年 | 374篇 |
2013年 | 2554篇 |
2012年 | 483篇 |
2011年 | 380篇 |
2010年 | 368篇 |
2009年 | 281篇 |
2008年 | 337篇 |
2007年 | 339篇 |
2006年 | 345篇 |
2005年 | 307篇 |
2004年 | 263篇 |
2003年 | 271篇 |
2002年 | 277篇 |
2001年 | 381篇 |
2000年 | 331篇 |
1999年 | 316篇 |
1998年 | 246篇 |
1997年 | 217篇 |
1996年 | 245篇 |
1995年 | 225篇 |
1994年 | 228篇 |
1993年 | 197篇 |
1992年 | 222篇 |
1991年 | 246篇 |
1990年 | 218篇 |
1989年 | 182篇 |
1988年 | 205篇 |
1987年 | 190篇 |
1986年 | 151篇 |
1985年 | 191篇 |
1984年 | 198篇 |
1983年 | 173篇 |
1982年 | 137篇 |
1981年 | 104篇 |
1980年 | 104篇 |
1979年 | 129篇 |
1978年 | 97篇 |
1977年 | 89篇 |
1976年 | 64篇 |
1975年 | 69篇 |
1974年 | 70篇 |
排序方式: 共有10000条查询结果,搜索用时 500 毫秒
61.
Summary Based on 14 case studies of highly effective therapies and the reasons they succeeded less frequently than they could, we
propose a variety of steps to improve the health care system of the U.S.A. Whatever proposal emerges from current national
debates until innovations are shown to be safe and effective, they should not be supported; when slightly better technologies
are much more expensive than other good ones we need to consider appropriate choices carefully; simplified billing and bookkeping
would reduce our costs; when a technology is rapidly introduced cautionnary measures may be needed; tracking immunization
and repairing their omissions requires a new system; educational programs such as seen effective in hypertension should be
applied in other areas such as vaccination; in organ transplantation the nation should consider “presumed consent”; our payment
system sometimes creates perverse incentives and therefore needs review; and the preferences of the public in allocation of
health resources need to be discovered once the public is informed about the issues.
Research supported by Andrew W. Mellon Foundation. 相似文献
62.
63.
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
64.
Mark Dickerson 《Journal of gambling studies / co-sponsored by the National Council on Problem Gambling and Institute for the Study of Gambling and Commercial Gaming》1993,9(3):225-245
Recent studies completed at the Australian National University focussing on poker machine players are reviewed and a speculative discussion attempts to link the various psychological processes that may contribute to the development of impaired control in regular poker machine players. On the assumption that there is some overlap between regular players and problem players in terms of their level of involvement in gambling, the theorising was extended to include problem players for whom an established habit was argued to be a necessary condition leading to impaired control. Two additional factors may be required for impaired control to be consistently present, negative emotions such as dysphoria and frustration, and indebtedness. Finally by drawing some limited contrasts with another popular, legal form of gambling, off-course betting, if was suggested that there may be different psychological processes causing impaired control in different forms of gambling. 相似文献
65.
In this paper we argue for the importance of a sociologically informed study of organizational accounting practices. By making the nexus between accounting and decision making problematic, instead of given, we move issues of interpretation and hierarchical control to the center stage of understanding the social construction of accounting practices. We suggest that inductive case studies of the organizational setting is a promising methodological strategy for identifying how accounting operates as an organizational control system. We focus on debates and proceedings of the board of directors as an overlooked source of data on decision making and organizational practices. We show how accounting practices are part of the strategic control system that functions to interpret the environment and direct the adaptation of the organization in a manner particular to the substantive rationality of corporate decision makers. We illustrate these contentions with a case study of accounting practice changes over a six year period. 相似文献
66.
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
67.
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
68.
69.
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
70.
Ratan S.J.B.Rana 《三峡大学学报(人文社会科学版)》2002,24(1):13-15
本文为第三届“文化与城市可持续发展”国际会议的主题发言。本文介绍了会议背景 ,论述了文化及其与可持续发展的关系 ,都市化进程及其发展方向等问题 ,并着重阐述了本次会议的主题即“城市可持续发展中的文化指标” ,确立了本次会议的总体基调和基本政策 相似文献