全文获取类型
收费全文 | 15420篇 |
免费 | 356篇 |
国内免费 | 1篇 |
专业分类
管理学 | 1976篇 |
民族学 | 114篇 |
人才学 | 4篇 |
人口学 | 1415篇 |
丛书文集 | 85篇 |
理论方法论 | 1360篇 |
综合类 | 123篇 |
社会学 | 7460篇 |
统计学 | 3240篇 |
出版年
2023年 | 73篇 |
2021年 | 85篇 |
2020年 | 227篇 |
2019年 | 299篇 |
2018年 | 397篇 |
2017年 | 534篇 |
2016年 | 370篇 |
2015年 | 314篇 |
2014年 | 362篇 |
2013年 | 2891篇 |
2012年 | 507篇 |
2011年 | 415篇 |
2010年 | 371篇 |
2009年 | 285篇 |
2008年 | 360篇 |
2007年 | 361篇 |
2006年 | 342篇 |
2005年 | 333篇 |
2004年 | 281篇 |
2003年 | 294篇 |
2002年 | 326篇 |
2001年 | 401篇 |
2000年 | 365篇 |
1999年 | 328篇 |
1998年 | 258篇 |
1997年 | 224篇 |
1996年 | 261篇 |
1995年 | 244篇 |
1994年 | 248篇 |
1993年 | 214篇 |
1992年 | 242篇 |
1991年 | 262篇 |
1990年 | 238篇 |
1989年 | 206篇 |
1988年 | 250篇 |
1987年 | 233篇 |
1986年 | 166篇 |
1985年 | 214篇 |
1984年 | 225篇 |
1983年 | 213篇 |
1982年 | 153篇 |
1981年 | 132篇 |
1980年 | 124篇 |
1979年 | 151篇 |
1978年 | 129篇 |
1977年 | 111篇 |
1976年 | 90篇 |
1975年 | 91篇 |
1974年 | 84篇 |
1973年 | 77篇 |
排序方式: 共有10000条查询结果,搜索用时 13 毫秒
821.
S.A. Shaban 《统计学通讯:理论与方法》2013,42(14):1389-1399
Recursion relations suitable for rapid computation are derived for the probabilities of the compound Poisson distribution when the compounder is the inverse-Gaussian distribution. Series representation of the probabilities are given. Asymptotic results as well as approximations for probabilities, compared with the exact values, are investigated. 相似文献
822.
We examine differences in the value of statistical life (VSL) across potential wage levels in panel data using quantile regressions
with intercept heterogeneity. Latent heterogeneity is econometrically important and affects the estimated VSL. Our findings
indicate that a reasonable average cost per expected life saved cut-off for health and safety regulations is 7 million to7 million to
8 million per life saved, but the VSL varies considerably across the labor force. Our results reconcile the previous discrepancies
between hedonic VSL estimates and the values implied by theories linked to the coefficient of relative risk aversion. Because the VSL varies elastically with income, regulatory agencies should regularly update the VSL used in benefit assessments,
increasing the VSL proportionally with changes in income over time. 相似文献
823.
824.
Rolffs S. Pinkerton Ph.D. W. J. Kenneth Rockwell M.D. 《Journal of American college health : J of ACH》2013,61(4):159-162
Abstract One or two session psychotherapy has a long history, and well-known practitioners have made use of it. Favorable results have been reasonably well documented. Often it has been done out of necessity, less frequently because all were satisfied that it sufficed. Problems that lend themselves to one or two sessions are: psychological work which has already been done but for which affirmation is sought, requests for diagnostic evaluation, and less often but more challenging, intrapsychic conflict requiring uncovering work. Patient characteristics and therapist attitudes are discussed. For one or two sessions of treatment to occur the therapist must be alert to the possibility, must assess quickly when a case is in hand, set the process in motion, and determine a satisfactory stopping point. It is suggested that the college population lends itself especially well to one or two sessions of psychotherapy, not only from the standpoint of the limited resources of many student health services but also for the ego strengthening potential it provides. 相似文献
825.
W.H. James 《Population studies》2013,67(3)
Extract I have suggested that at a given birth order the probability of having a further pregnancy is greater when the last pregnancy had been spontaneously aborted than when it resulted in a birth.2 Léridon,3in the course of a valuable paper on foetal wastage, presents data which, according to him, impugn my suggestion. I would like to question his claim. 相似文献
826.
Lot resubmissions are allowed in situations where the original inspection results are suspected or when the supplier is allowed to opt for resampling as per the provisions of the contract etc. This paper examines the situation of resampling of lots and derives the performance measures of a resampling scheme having a single sampling plan for inspection. The usefulness and limitations of resampling of resubmitted lots are also discussed 相似文献
827.
828.
829.
830.
Abstract The present study examines the stability of bright light circadian readjustment during two consecutive dim light night-work periods and circadian synchronization during the recovery after a night-shift period. A sample of 10 subjects was divided into 2 groups (control group: 6 subjects; experimental group: 4 subjects). All subjects worked during 5 days, between 23:00 and 07:00 h and then went to sleep. Subjects received 2500-3000 lux between 02:00 and 05:00 h during 5 days for the control group and 3 days for the experimental group. During recovery after the night-shift periods, three cycles of bright light were administered at two different times: 12:00-15:00 h for two of six subjects from the control group and 10:00-13:00 h for all subjects (4) of the experimental group. By the fifth cycle of night-work the maximum of urinary aMT6s excretion that occurs at 05:00 h in the baseline condition was shifted to 12:00 h for the control and experimental groups (delay in hours: 7±1.6 (control); 7±1 (experimental)). This result suggests that three cycles of bright light are sufficient to induce a significant phase delay and that this delay remained stable when night-work proceeded under dim light. The phase delay of the circadian aMT6s excretion by exposure to bright light was accompanied by an improvement of the quality of day sleep and level of cognitive and psychomotor performances for control and experimental groups. No significant difference was observed in the two groups for daytime sleep and nocturnal performance. The two bright light periods used during the three days of recovery induced a complete synchronization in five of six subjects. One subject showed a partial synchronization probably because he remained at the laboratory under dim light during the day and had few family and social contacts. 相似文献