全文获取类型
收费全文 | 17613篇 |
免费 | 308篇 |
国内免费 | 3篇 |
专业分类
管理学 | 2412篇 |
民族学 | 94篇 |
人才学 | 3篇 |
人口学 | 1646篇 |
丛书文集 | 101篇 |
理论方法论 | 1683篇 |
综合类 | 305篇 |
社会学 | 8769篇 |
统计学 | 2911篇 |
出版年
2020年 | 241篇 |
2019年 | 374篇 |
2018年 | 419篇 |
2017年 | 602篇 |
2016年 | 430篇 |
2015年 | 316篇 |
2014年 | 404篇 |
2013年 | 2949篇 |
2012年 | 555篇 |
2011年 | 524篇 |
2010年 | 405篇 |
2009年 | 388篇 |
2008年 | 390篇 |
2007年 | 421篇 |
2006年 | 416篇 |
2005年 | 410篇 |
2004年 | 385篇 |
2003年 | 306篇 |
2002年 | 353篇 |
2001年 | 425篇 |
2000年 | 374篇 |
1999年 | 369篇 |
1998年 | 297篇 |
1997年 | 288篇 |
1996年 | 268篇 |
1995年 | 242篇 |
1994年 | 254篇 |
1993年 | 249篇 |
1992年 | 255篇 |
1991年 | 266篇 |
1990年 | 269篇 |
1989年 | 279篇 |
1988年 | 210篇 |
1987年 | 248篇 |
1986年 | 200篇 |
1985年 | 251篇 |
1984年 | 246篇 |
1983年 | 240篇 |
1982年 | 198篇 |
1981年 | 166篇 |
1980年 | 179篇 |
1979年 | 185篇 |
1978年 | 182篇 |
1977年 | 137篇 |
1976年 | 151篇 |
1975年 | 154篇 |
1974年 | 151篇 |
1973年 | 112篇 |
1972年 | 89篇 |
1971年 | 88篇 |
排序方式: 共有10000条查询结果,搜索用时 12 毫秒
41.
Abstract Using data from a national survey in Bolivia and from a regional sample of poor communities in two regions of Bolivia, we model the effects of community conditions, household characteristics, and social relations on child health as measured by child mortality and stunted growth. Based on national data, children in rural areas are twice as likely to die before the age of two than are children in large cities, and about one‐third of the children in rural areas are stunted. Including measures of community, household, and maternal characteristics accounts for at least two‐thirds of the urban/rural difference in child health. We conclude that expansion of health services, improvements in household and community sanitation, and socioeco‐nomic development are all needed to overcome the rural disadvantage in child health. 相似文献
42.
While shows like The X-Files and 24 have merged conspiracy theories with popular science (fictions), some video games have been pushing the narrative even further. Electronic Art's Majestic game was released in July 2001 and quickly generated media buzz with its unusual multi-modal gameplay. Mixing phone calls, faxes, instant messaging, real and "fake' websites, and email, the game provides a fascinating case of an attempt at new directions for gaming communities. Through story, mode of playing, and use of technology, Majestic highlights the uncertain status of knowledge, community and self in a digital age; at the same time, it allows examination of alternative ways of understanding games' role and purpose in the larger culture. Drawing on intricate storylines involving government conspiracies, techno-bio warfare, murder and global terror, players were asked to solve mysteries in the hopes of preventing a devastating future of domination. Because the game drew in both actual and Majestic-owned/-designed websites, it constantly pushed those playing the game right to borders where simulation collides with " factuality'. Given the wide variety of "legitimate' conspiracy theory, alien encounters and alternative science web pages, users often could not distinguish when they were leaving the game's pages and venturing into " real' World Wide Web sites. Its further use of AOL's instant messenger system, in which gamers spoke not only to bots but to other players, pushed users to evaluate constantly both the status of those they were talking to and the information being provided. Additionally, the game required players to occupy unfamiliar subject positions, ones where agency was attenuated, and which subsequently generated a multi-layered sense of unease among players. This mix of authentic and staged information in conjunction with technologically mediated roles highlights what are often seen as phenomenon endemic to the Internet itself; that is, the destabilization of categories of knowing, relating, and being. 相似文献
43.
44.
Stolzenberg Lisa D'Alessio Stewart J. Rivers James E. Newell Augusto L. 《Social indicators research》2003,61(1):19-57
Determining the size and demographiccharacteristics of substance abuse populationsis extremely important for implementing publicpolicies aimed at the control of substanceabuse. Such information not only assists in theallocation of limited treatment resources bythe state, but also in the monitoring ofsubstance abuse trends over time and in theevaluation of innovative policy initiatives. Inthis study, we develop three composite measuresof treatment need. We then use these measuresto estimate treatment need for alcohol abuseand for controlled substance abuse within eachof Florida's 67 counties. This study providesan important empirical component of communityplanning, quantifying and, to a limited degree,specifying the level of need for the substanceabuse treatment of community residents. Anadditional benefit is the development of a costeffective and unobtrusive methodology fordetermining empirically when levels of need arechanging so that treatment levels can beadjusted accordingly. With proper use,policymakers can readily employ the methodologydeveloped in this study in Florida andelsewhere to make better-informed decisions inthe allocation of finite substance abusetreatment resources. 相似文献
45.
1. Most diagnosed cases of tardive dyskinesia (TD) are mildly inconvenient to the patient, but some can be severe or life-threatening. The primary goal of intervention should be early identification of abnormal movements related to TD and the prescribing of an appropriate medication regimen. 2. Unless specific training occurs and a specific monitoring system is in place, TD movements may be missed. However, not all movements are necessarily related to TD. 3. Although screening and monitoring are valuable, nothing is more important than prevention. New medications must be developed that do not carry the risk of TD, and other approaches to treat TD must be developed. 相似文献
46.
47.
48.
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
49.
The authors investigated the prevalence of recurrent pain in a college student sample. Of the 1,564 students surveyed, 467 (29%) indicated that they had experienced recurrent pain at an intensity that was mostly in the mild-to-moderate range. Students who reported having recurrent pain were significantly older and more depressed than students who did not indicate they suffered from recurrent pain. Pain intensity was positively correlated (r = .14) with depression among the students who reported having recurrent pain. Implications of the findings for future research, treatment, and health promotion efforts are discussed. 相似文献
50.
THE INFLUENCE OF ECONOMICS ON ANTITRUST LAW 总被引:1,自引:0,他引:1
WILLIAM E. KOVACIC 《Economic inquiry》1992,30(2):294-306
Economists today play prominent roles in formulating antitrust policy and litigating antitrust cases. This paper explains why economics influences antitrust law and describes how economic theories enter and shape the antitrust system. Antitrust policy and doctrine change over time in response to developments in economic theory, and the decentralization of the antitrust adjudication system and the wide latitude accorded judges in interpreting antitrust statutes ensure that legal rules will reflect advances in the economic literature concerning the appropriate content of standards governing business conduct. 相似文献