全文获取类型
收费全文 | 18976篇 |
免费 | 494篇 |
国内免费 | 1篇 |
专业分类
管理学 | 2465篇 |
民族学 | 77篇 |
人口学 | 1614篇 |
丛书文集 | 86篇 |
教育普及 | 3篇 |
理论方法论 | 1692篇 |
综合类 | 239篇 |
社会学 | 9484篇 |
统计学 | 3811篇 |
出版年
2023年 | 107篇 |
2020年 | 244篇 |
2019年 | 383篇 |
2018年 | 390篇 |
2017年 | 586篇 |
2016年 | 405篇 |
2015年 | 334篇 |
2014年 | 425篇 |
2013年 | 3695篇 |
2012年 | 538篇 |
2011年 | 500篇 |
2010年 | 398篇 |
2009年 | 362篇 |
2008年 | 440篇 |
2007年 | 430篇 |
2006年 | 424篇 |
2005年 | 379篇 |
2004年 | 315篇 |
2003年 | 294篇 |
2002年 | 318篇 |
2001年 | 432篇 |
2000年 | 404篇 |
1999年 | 413篇 |
1998年 | 290篇 |
1997年 | 270篇 |
1996年 | 328篇 |
1995年 | 317篇 |
1994年 | 301篇 |
1993年 | 344篇 |
1992年 | 355篇 |
1991年 | 326篇 |
1990年 | 359篇 |
1989年 | 308篇 |
1988年 | 298篇 |
1987年 | 276篇 |
1986年 | 258篇 |
1985年 | 249篇 |
1984年 | 278篇 |
1983年 | 218篇 |
1982年 | 208篇 |
1981年 | 163篇 |
1980年 | 197篇 |
1979年 | 213篇 |
1978年 | 167篇 |
1977年 | 161篇 |
1976年 | 150篇 |
1975年 | 170篇 |
1974年 | 119篇 |
1973年 | 105篇 |
1972年 | 106篇 |
排序方式: 共有10000条查询结果,搜索用时 406 毫秒
21.
22.
23.
A NOTE ON EVANESCENT PROCESSES 总被引:1,自引:0,他引:1
This note examines the connection between μ-invariant measures for the transition function of a continuous-time Markov chain and those of its q-matrix, Q. The major result establishes a necessary and aufficient condition for a convergent μ-invariant measure for Q to be μ-inhant for the minimal transition function, P, under the assumption that P is honest. This corrects Theorem 6 of Vere-Jones (1969) and the first part of Corollary 1 of Pollett (1986), both of which assert that the above conclusion holds in the absence of this condition. The error was pointed out by E.A. van Doom (1991) and the counterexample which be presented provides the basis for the present arguments. In determining where the error occurred in the original proof, we are able to identify a simple sufficient condition for μ-invariance. 相似文献
24.
A role-reversal in the mother-daughter relationship 总被引:1,自引:1,他引:0
Roberta Kabat Ph.D. 《Clinical Social Work Journal》1996,24(3):255-269
Psychoanalytic theorists have noted a particular dynamic in the mother-infant relationship in which the emotional needs of the mother predominate. When this situation occurs, the emotional needs of the infant may go unmet, resulting in impaired self-development. Through an integration of the ideas of mainstream psychoanalytic theorists and feminist psychoanalytic thinkers, this paper proposes the idea that, because of the intensity of the mother-daughter relationship, this dynamic may be more prevalent between mothers and daughters than between mothers and sons. A mother-daughter relationship is described in which the mother comes to depend on her daughter for emotional attunement and response, and the mother's selfobject needs predominate. As a consequence, the daughter is unable to develop a cohesive sense of self and experiences difficulty in achieving separation. Two clinical reports are presented to illustrate the way in which this mother-daughter dynamic manifests itself in the patient's life and in the therapeutic relationship. A negative transference dynamic is described resulting from these patient's fear of duplicating their relationship with their mothers in the therapeutic relationship by having to meet the selfobject needs of the therapist. 相似文献
25.
Fred P. Piercy Douglas H. Sprenkle Susan H. McDaniel 《Journal of marital and family therapy》1996,22(2):163-179
The authors present three educational approaches designed to demystify the writing process and to support better writing skills among family therapists. One framework is an academic course in professional writing, another is a writing seminar for family therapy and physician trainees within a medical school setting, and the third is a 2-hour continuing education writing workshop for family therapists. Each is replicable within a variety of settings. 相似文献
26.
This paper describes the design optimization of a robot sensor used for locating 3-D objects employing the Taguchi method in a computer simulation scenario. The location information from the sensor is to be utilized to control the movements of an industrial robot in a 'pick-and-place' or assembly operation. The Taguchi method, which is based on the Analysis-of-Variance (ANOVA) approach, is utilized to improve the performance of the sensor over a wider operating range. A review of the Taguchi method is presented along with step-by-step implementation details to identify and optimize the design parameters of the sensor. The method allows us to gauge the impact of various interactions present in the sensor system exclusively and permits us to single out those factors that have a dominant influence on the overall performance of the sensor. The investigation suggests that the Taguchi method is a more structured and efficient approach for achieving a robust design compared with the classical full factorial design approach. 相似文献
27.
Patrick D. Bourke 《Journal of applied statistics》2002,29(8):1121-1133
A Continuous Sampling Plan, CSP-CUSUM, is proposed based on the use of Cumulative Sums (CUSUMs) for deciding when to switch between the phases of sampling inspection and 100% inspection. The Geometric CUSUM, also termed the Run-length CUSUM, is chosen for this purpose, and two separate CUSUMs are to be operated, one for each inspection phase. The conventional measures of performance for CSPs such as average outgoing quality, average fraction inspected, and average proportion passed under sampling inspection are evaluated for CSP-CUSUM, and comparisons with some standard CSPs are presented. An additional performance-measure, Average Cycle Length, is proposed. A table is provided to aid the choice of parameters for the operation of CSP-CUSUM. It is recommended that a Geometric CUSUM control chart be maintained in parallel with CSP-CUSUM to detect significant upward shifts in the incoming fraction defective. 相似文献
28.
29.
Jonathan H. Wright 《Econometric Reviews》2002,21(4):397-417
Many recent papers have used semiparametric methods, especially the log-periodogram regression, to detect and estimate long memory in the volatility of asset returns. In these papers, the volatility is proxied by measures such as squared, log-squared, and absolute returns. While the evidence for the existence of long memory is strong using any of these measures, the actual long memory parameter estimates can be sensitive to which measure is used. In Monte-Carlo simulations, I find that if the data is conditionally leptokurtic, the log-periodogram regression estimator using squared returns has a large downward bias, which is avoided by using other volatility measures. In United States stock return data, I find that squared returns give much lower estimates of the long memory parameter than the alternative volatility measures, which is consistent with the simulation results. I conclude that researchers should avoid using the squared returns in the semiparametric estimation of long memory volatility dependencies. 相似文献
30.
A sample size justification should be given for all clinical investigations. However, sometimes the objective of a trial is to estimate an effect with a view to planning a later definitive study. This paper describes the calculations for designing studies where one wishes to adopt an estimation approach through using confidence intervals around the overall response. Calculations are given for data anticipated to take a Normal form. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献