全文获取类型
收费全文 | 16659篇 |
免费 | 431篇 |
专业分类
管理学 | 2397篇 |
民族学 | 83篇 |
人才学 | 3篇 |
人口学 | 1678篇 |
丛书文集 | 96篇 |
教育普及 | 1篇 |
理论方法论 | 1660篇 |
现状及发展 | 1篇 |
综合类 | 180篇 |
社会学 | 8158篇 |
统计学 | 2833篇 |
出版年
2023年 | 103篇 |
2020年 | 244篇 |
2019年 | 322篇 |
2018年 | 345篇 |
2017年 | 487篇 |
2016年 | 418篇 |
2015年 | 276篇 |
2014年 | 379篇 |
2013年 | 2968篇 |
2012年 | 540篇 |
2011年 | 450篇 |
2010年 | 380篇 |
2009年 | 386篇 |
2008年 | 427篇 |
2007年 | 422篇 |
2006年 | 389篇 |
2005年 | 430篇 |
2004年 | 439篇 |
2003年 | 379篇 |
2002年 | 418篇 |
2001年 | 418篇 |
2000年 | 394篇 |
1999年 | 382篇 |
1998年 | 288篇 |
1997年 | 262篇 |
1996年 | 250篇 |
1995年 | 257篇 |
1994年 | 223篇 |
1993年 | 248篇 |
1992年 | 245篇 |
1991年 | 238篇 |
1990年 | 215篇 |
1989年 | 238篇 |
1988年 | 214篇 |
1987年 | 183篇 |
1986年 | 199篇 |
1985年 | 226篇 |
1984年 | 219篇 |
1983年 | 207篇 |
1982年 | 177篇 |
1981年 | 152篇 |
1980年 | 145篇 |
1979年 | 178篇 |
1978年 | 129篇 |
1977年 | 129篇 |
1976年 | 128篇 |
1975年 | 122篇 |
1974年 | 107篇 |
1973年 | 101篇 |
1971年 | 76篇 |
排序方式: 共有10000条查询结果,搜索用时 204 毫秒
41.
This paper proposes a new concept of rural development in an uncertain world. The nature of risk and uncertainty is discussed and risk management is defined as a positive model of economic and social behaviour. Some relevant paradigms for rural development are reviewed and evaluated within the general approach of risk management. It is demonstrated that the proposed view of risk management can effectively combine and reconcile different approaches by highlighting their advantages and shortcomings. Departing from a subjective definition of risk management, we progressively include its social dimensions which introduce both complexity and structure into the process of rural development. 相似文献
42.
Owing to the extreme quantiles involved, standard control charts are very sensitive to the effects of parameter estimation and non-normality. More general parametric charts have been devised to deal with the latter complication and corrections have been derived to compensate for the estimation step, both under normal and parametric models. The resulting procedures offer a satisfactory solution over a broad range of underlying distributions. However, situations do occur where even such a large model is inadequate and nothing remains but to consider non- parametric charts. In principle, these form ideal solutions, but the problem is that huge sample sizes are required for the estimation step. Otherwise the resulting stochastic error is so large that the chart is very unstable, a disadvantage that seems to outweigh the advantage of avoiding the model error from the parametric case. Here we analyse under what conditions non-parametric charts actually become feasible alternatives for their parametric counterparts. In particular, corrected versions are suggested for which a possible change point is reached at sample sizes that are markedly less huge (but still larger than the customary range). These corrections serve to control the behaviour during in-control (markedly wrong outcomes of the estimates only occur sufficiently rarely). The price for this protection will clearly be some loss of detection power during out-of-control. A change point comes in view as soon as this loss can be made sufficiently small. 相似文献
43.
Zhu Carolyn W. Moore Michael J. Clipp Elizabeth C. 《Review of Economics of the Household》2003,1(1-2):59-76
Informal caregivers of individuals with Alzheimer's disease spend a considerable amount of time providing care. In this paper, we use Grossman's health production and Becker's time allocation models to develop a model of informal care provision to elderly dementia patients. In our model, time inputs produce caregiving services, which provides utility to the caregiver, but reduces leisure. We assume that time is less productive of services on the margin as the disease progresses. In this framework, an increase in patients' disease severity does not necessarily increase informal caregiver time input. The cost of formal care establishes a reservation price for informal caregiving. When the costs of informal caregiving rise above this reservation level, the patient is institutionalized. We test empirically the effect of deterioration in the patients' condition, proxied by both disease severity and dementia problem behavior, on informal caregiving time. We find that dementia-related problem behaviors and functional limitations significantly increase inputs of informal caregiving time. Patients' problem behavior exerts a modifying effect on functional limitations, and patients' comorbidities have no effect on informal caregiving time. 相似文献
44.
45.
Craig H. Mallinckrodt John G. Watkin Geert Molenberghs Raymond J. Carroll 《Pharmaceutical statistics》2004,3(3):161-169
Missing data, and the bias they can cause, are an almost ever‐present concern in clinical trials. The last observation carried forward (LOCF) approach has been frequently utilized to handle missing data in clinical trials, and is often specified in conjunction with analysis of variance (LOCF ANOVA) for the primary analysis. Considerable advances in statistical methodology, and in our ability to implement these methods, have been made in recent years. Likelihood‐based, mixed‐effects model approaches implemented under the missing at random (MAR) framework are now easy to implement, and are commonly used to analyse clinical trial data. Furthermore, such approaches are more robust to the biases from missing data, and provide better control of Type I and Type II errors than LOCF ANOVA. Empirical research and analytic proof have demonstrated that the behaviour of LOCF is uncertain, and in many situations it has not been conservative. Using LOCF as a composite measure of safety, tolerability and efficacy can lead to erroneous conclusions regarding the effectiveness of a drug. This approach also violates the fundamental basis of statistics as it involves testing an outcome that is not a physical parameter of the population, but rather a quantity that can be influenced by investigator behaviour, trial design, etc. Practice should shift away from using LOCF ANOVA as the primary analysis and focus on likelihood‐based, mixed‐effects model approaches developed under the MAR framework, with missing not at random methods used to assess robustness of the primary analysis. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
46.
47.
John Grin 《Poiesis & praxis》2004,2(2-3):157-174
In this contribution, I wish to explore the potential of health technology assessment and ethics for increasing our capacity to pre-empt the shortcomings and undesired consequences of modern health care while maintaining its benefits. Central is the presumption that in case of some health problems this cannot be done unless we explicitly reconsider some features of the modern health care system, especially those related to its strong reliance on scientific rationality and the strong role played by medical professionals. So as to both maintain the benefits of advanced health care and ensure that it produces less reason for concern, we need to reconsider our approach to rationality—and maybe even the way in which we build our health care system around that rationality. That is, we need to introduce an element of reflexivity. Two types of circumstances are being explored in which such reflexivity may prove worthwhile: controversies on side effects, and persistent problems encountered in optimising health care. Drawing on brief discussions of typical cases, we explore the potential of reflexive HTA and its methodical prerequisites. We conclude that ethicists may contribute to reflexive HTA, if they combine a hermeneutic—and often also participative—methodology with a solid understanding of the relation between the health problem under scrutiny and more general critique of the health care system. Insights from the areas of science and technology studies, as well as from social philosophy may be critical items in their tool kit. 相似文献
48.
The authors examine facilitative aspects of field research with deviant street populations. Based on the authors' research with the homeless and with male street prostitutes, the facilitative aspects include access to settings, social relationships, acquisition of information, and the maintenance of researcher interest. The authors argue that in each of these aspects street deviants may in some ways be easier to study than other populations. The paper concludes with suggestions for maximizing the efficiency and quality of fieldwork with specific deviant populations. 相似文献
49.
The present article assesses the adversary systemper se and asks the question, Is there any place for courtroom antics and histrionics in cases involving children? Social workers are uncomfortable before the august body of thecourt, not because of any lack of education or knowledge on their part but because of the nature of the adversary process itself. 相似文献
50.
In our zeal to deal with alcohol and drug abuse, we may have a distorted picture of what the majority of college students actually think about alcohol and drug use. Students in this study done at a public university located in the Deep South report being generally intolerant of substance abuse. 相似文献