全文获取类型
收费全文 | 14760篇 |
免费 | 364篇 |
专业分类
管理学 | 1914篇 |
民族学 | 79篇 |
人才学 | 1篇 |
人口学 | 1250篇 |
丛书文集 | 87篇 |
教育普及 | 3篇 |
理论方法论 | 1326篇 |
综合类 | 135篇 |
社会学 | 7848篇 |
统计学 | 2481篇 |
出版年
2023年 | 72篇 |
2021年 | 81篇 |
2020年 | 190篇 |
2019年 | 281篇 |
2018年 | 308篇 |
2017年 | 428篇 |
2016年 | 328篇 |
2015年 | 255篇 |
2014年 | 324篇 |
2013年 | 2957篇 |
2012年 | 385篇 |
2011年 | 401篇 |
2010年 | 302篇 |
2009年 | 277篇 |
2008年 | 326篇 |
2007年 | 330篇 |
2006年 | 317篇 |
2005年 | 309篇 |
2004年 | 267篇 |
2003年 | 249篇 |
2002年 | 290篇 |
2001年 | 349篇 |
2000年 | 332篇 |
1999年 | 325篇 |
1998年 | 222篇 |
1997年 | 204篇 |
1996年 | 253篇 |
1995年 | 262篇 |
1994年 | 266篇 |
1993年 | 267篇 |
1992年 | 276篇 |
1991年 | 263篇 |
1990年 | 281篇 |
1989年 | 247篇 |
1988年 | 256篇 |
1987年 | 231篇 |
1986年 | 188篇 |
1985年 | 207篇 |
1984年 | 219篇 |
1983年 | 181篇 |
1982年 | 153篇 |
1981年 | 137篇 |
1980年 | 140篇 |
1979年 | 145篇 |
1978年 | 130篇 |
1977年 | 113篇 |
1976年 | 115篇 |
1975年 | 113篇 |
1974年 | 73篇 |
1973年 | 69篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Lee RD 《Journal of the American Statistical Association》1974,69(347):607-617
Time series analysis of fertility can improve demographic forecasts. The optimal forecast and its variance for births to an age-structured population subject to serially correlated random fertility are developed. The general case in which the fertility process had arbitrary autoregressive structure is dealt with and then the 4 special cases of white noise, 1st-order autoregressive, 2nd-order autoregressive, and random walk are considered. Consequently, it is determined that the predictions and their variances are highly sensitive to the autoregressive structure of fertility and, therefore, if stochastic models are to be used for prediction, they must emphasize this aspect of the problem. Preliminary empirical efforts to model the time series of U.S. fertility from 1917 to 1972 proved unsuccessful, but it is obvious that at least a 2nd-order autoregressive scheme is require d. The analysis proveded should be helpful in: 1) any application of the procedures requires a successful parameterization of the fertility process; 2) fertility variations could be decomposed into the effects of nuptiality and marital fertility and then births and marriages could be jointly predicted; and 3) the simplifying approximations should be dropped and each age-specific rate could be analyzed and predicted. 相似文献
992.
Wolfers D 《Population studies》1971,25(3):535-536
Abstract Contraceptive use in the early post-partum months is, for the majority of women, without any direct protective value because, whilst not ovulating, they are not exposed to the risk of pregnancy. This does not, of course, imply that contraception should be delayed until signs of the resumption of ovulation appear, as for many women the first sign of such resumption is pregnancy. There are, besides, logistic and psychological reasons which make early post-partum contraception advisable. It does, however, demand that any calculation of the demographic effects of contraceptive use should make due allowance for this null period of use. 相似文献
993.
994.
995.
996.
997.
Conclusions Social agency practitiooners can employ adolescent group therapy as an effective treatment mode, as long as a great deal of attention and planning is put into the details of group membership selection. The authors have presented suggestions and guidelines that can be used in overcoming the logistic problems inherent in forming an adolescent therapy group. We feel that proper pregroup planning is just as important in determining group results as is the ongoing group process. Group treatment does not necessarily incease a therapist's productivity or reduce the amount of time spent in therapy, but it does offer a unique experience which has certain qualitative advantages for teenagers experiencing behavioral and relationship problems within and, particularly, outside of the family system. 相似文献
998.
With an identical data base—the SRCICPS election studiesconducted over the 1952–1976 period—scholars arriveat conflicting conclusions about the future politics of theSouth. One problem is alternative regional definitions—thesurvey category Solid South (which includes the states of theformer Confederacy minus Tennessee) or the combined categoriesSolid South and Border South. Another problem is the choiceto analyze native whites, whites, or all election participants.Based on data presented here, these choices are not neutral;rather, they influence the research findings. If the intentis to build upon the aggregate data-based research of Key andothers, one should use the Solid South definition. Moreover,if the intent is to predict about the future politics of theSouth, one should analyze all election participants. 相似文献
999.
Roberts DF 《Population studies》1971,25(3):465-479
Abstract The eruption of the volcano on Tristan da Cunha in 1961 and the subsequent arrival of the island population in the United Kingdom provided a unique opportunity for studying the health of this formerly isolated community. During their stay, while the facilities and services of modern medicine were made available to them, investigations of many facets of their general biology were made under the auspices of the Medical Research Council, co-ordinated by Dr. H. E. Lewis. Analysis of their demographic history was essential to understand many features of their disease pattern, and the results of this analysis are presented here. They are of interest in that they not only show some consistent trends in the common variables of demography, but also demonstrate biological principles, some perhaps for the first time in man, which may be fundamental in the process of colonization as a biological phenomenon, e.g. the initial difficulty of establishment of a population in a new area, the curious demographic structure that may emerge in its earliest years, the bottleneck effect of population-size reduction, the founder principle. 相似文献
1000.
How do family arrangements affect subjective well-being? We investigate this issue using data pooled from the IsssA and HILDA, both large, representative national samples of Australia (pooled n=38 447). Our regression analysis of cross-sectional and panel data examines how large are the differences in life satisfaction according to marital status and cohabitation. We find that women and men in formal marriages experience higher levels of life satisfaction than do people in other family arrangements. Moreover, both multiple tests in the cross-section, and tests controlling for prior happiness in the panel analysis, suggest that this is a causal relationship. Aggregating up the levels of life satisfaction generated by different marriage and cohabitation arrangements across a lifetime, suggests that a life-long marriage is the most satisfying. Early divorce followed by an enduring second marriage is little worse (because little time is spent outside the married state). But divorce without remarriage, or long lasting cohabitation without formal marriage, reduce the lifetime sum of subjective well-being by 4–12% for both women and men. 相似文献