全文获取类型
收费全文 | 19560篇 |
免费 | 458篇 |
国内免费 | 2篇 |
专业分类
管理学 | 2727篇 |
民族学 | 74篇 |
人才学 | 1篇 |
人口学 | 1706篇 |
丛书文集 | 93篇 |
教育普及 | 2篇 |
理论方法论 | 1796篇 |
综合类 | 419篇 |
社会学 | 9836篇 |
统计学 | 3366篇 |
出版年
2020年 | 270篇 |
2019年 | 329篇 |
2018年 | 373篇 |
2017年 | 521篇 |
2016年 | 421篇 |
2015年 | 327篇 |
2014年 | 395篇 |
2013年 | 3237篇 |
2012年 | 558篇 |
2011年 | 501篇 |
2010年 | 353篇 |
2009年 | 374篇 |
2008年 | 428篇 |
2007年 | 441篇 |
2006年 | 392篇 |
2005年 | 511篇 |
2004年 | 438篇 |
2003年 | 375篇 |
2002年 | 403篇 |
2001年 | 449篇 |
2000年 | 444篇 |
1999年 | 432篇 |
1998年 | 329篇 |
1997年 | 306篇 |
1996年 | 331篇 |
1995年 | 304篇 |
1994年 | 324篇 |
1993年 | 292篇 |
1992年 | 357篇 |
1991年 | 363篇 |
1990年 | 359篇 |
1989年 | 341篇 |
1988年 | 334篇 |
1987年 | 305篇 |
1986年 | 306篇 |
1985年 | 289篇 |
1984年 | 337篇 |
1983年 | 314篇 |
1982年 | 248篇 |
1981年 | 210篇 |
1980年 | 217篇 |
1979年 | 260篇 |
1978年 | 218篇 |
1977年 | 185篇 |
1976年 | 170篇 |
1975年 | 146篇 |
1974年 | 162篇 |
1973年 | 134篇 |
1972年 | 95篇 |
1971年 | 98篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
931.
Christopher R. Heathcote Borek D. Puza Steven P. Roberts 《Australian & New Zealand Journal of Statistics》2009,51(4):481-497
We consider two related aspects of the study of old‐age mortality. One is the estimation of a parameterized hazard function from grouped data, and the other is its possible deceleration at extreme old age owing to heterogeneity described by a mixture of distinct sub‐populations. The first is treated by half of a logistic transform, which is known to be free of discretization bias at older ages, and also preserves the increasing slope of the log hazard in the Gompertz case. It is assumed that data are available in the form published by official statistical agencies, that is, as aggregated frequencies in discrete time. Local polynomial modelling and weighted least squares are applied to cause‐of‐death mortality counts. The second, related, problem is to discover what conditions are necessary for population mortality to exhibit deceleration for a mixture of Gompertz sub‐populations. The general problem remains open but, in the case of three groups, we demonstrate that heterogeneity may be such that it is possible for a population to show decelerating mortality and then return to a Gompertz‐like increase at a later age. This implies that there are situations, depending on the extent of heterogeneity, in which there is at least one age interval in which the hazard function decreases before increasing again. 相似文献
932.
Obesity is considered a major cause of premature mortality and a potential threat to the longstanding secular decline in mortality
in the United States. We measure relative and attributable risks associated with obesity among middle-aged adults using data
from the Health and Retirement Study (1992–2004). Although class II/III obesity (BMI _ 35.0 kg/m2) increases mortality by
40% in females and 62% in males compared with normal BMI (BMI = 18.5-24.9), class I obesity (BMI = 30.0-34.9) and being overweight
(BMI = 25.0-29.9) are not associated with excess mortality. With respect to attributable mortality, class II/III obesity (BMI
_ 35.0) is responsible for approximately 4% of deaths among females and 3% of deaths among males. Obesity is often compared
with cigarette smoking as a major source of avoidable mortality. Smoking-attributable mortality is much larger in this cohort:
about 36% in females and 50% in males. Results are robust to confounding by preexisting diseases, multiple dimensions of socioeconomic
status (SES), smoking, and other correlates. These findings challenge the viewpoint that obesity will stem the long-term secular
decline in U.S. mortality. 相似文献
933.
Joshua R. Goldstein Tomáš Sobotka Aiva Jasilioniene 《Population and development review》2009,35(4):663-699
Total fertility rates fell to previously unseen levels in a large number of countries beginning in the early 1990s. The persistence of TFRs below 1.3 raised the possibility of rapid population aging and decline. We discuss the recent widespread turnaround in so‐called lowest‐low‐fertility countries in Europe and East Asia. The number of countries with TFRs below 1.3 fell from 21 in 2003 to five in 2008. Moreover, the upturn in the TFR was not confined to lowest‐fertility countries, but affected the whole developed world. We explore the demographic explanations for the recent rise in TFRs stemming from fertility timing effects as well as economic, policy, and social factors. Although the current economic downturn may suppress TFRs in the short run, we conclude that formerly lowest‐low‐fertility countries will continue to see increases in fertility as the transitory effects of shifts to later childbearing become less important. 相似文献
934.
Using confidential microdata from the US Census Bureau, we investigate the performance of Asian-owned businesses. Using regression
estimates and a special non-linear decomposition technique, we explore the role that class resources, such as financial capital
and human capital, play in contributing to the relative success of Asian businesses. We find that Asian-owned businesses are
more successful than white-owned businesses for two main reasons—Asian owners have high levels of human capital and their
businesses have substantial start-up capital. Using detailed information on both the owner and the firm, we estimate the explanatory
power of several additional factors.
相似文献
Robert W. Fairlie (Corresponding author)Email: |
935.
The effects of under‐skilling on need for recovery,losing employment and retirement intentions among older office workers: A prospective cohort study
下载免费PDF全文
![点击此处可从《International labour review / International Labour Office》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Fleur G. GOMMANS Nicole W.H. JANSEN Dave STYNEN IJmert KANT Andries de GRIP 《International labour review / International Labour Office》2017,156(3-4):525-548
Based on a sample of older workers from the Maastricht Cohort Study, the authors investigate the prevalence and dynamics of self‐reported under‐skilling and its effects on workers' need for recovery, their risk of losing employment and their retirement intentions over a two‐year period. They find that being under‐skilled is associated both with higher levels of need for recovery over time and with the risk of losing employment, but not with early retirement intentions. To achieve sustainable employment, they argue, the course of under‐skilling should be monitored throughout workers' careers, enabling timely interventions to avoid its negative consequences. 相似文献
936.
937.
938.
939.
940.
Scott W. Semenyna Doug P. VanderLaan Lanna J. Petterson Paul L. Vasey 《Journal of sex research》2017,54(8):1077-1084
Previous research established that male androphilia (i.e., sexual arousal and attraction to adult males) clusters in families. Some studies find that male androphilia clusters in both the paternal and maternal lines, while others find that it clusters only in the latter. Most of the research investigating the familial nature of male androphilia has taken place in Western cultural contexts that are problematic for such research because they are characterized by low fertility. To address this, our previous work has examined familial patterning of male androphilia in Samoa, a high-fertility population in which androphilic males are readily identified due to their public status as fa’afafine (a third gender category). Building on this work, the present study replicated the familial nature of male androphilia in Samoa using a sample size that was ~122% larger than the one we previously employed (N = 382, M ±SD age: 29.72 years ±10.16). Samoan fa’afafine had significantly more fa’afafine relatives in their maternal and paternal lines compared to Samoan gynephilic males (p < .001). The prevalence of male androphilia was equivalent across both the paternal and maternal lines (all p > .15). The revised prevalence estimate of male androphilia in Samoa falls between 0.61% and 3.51%. 相似文献