全文获取类型
收费全文 | 8523篇 |
免费 | 235篇 |
专业分类
管理学 | 1234篇 |
民族学 | 45篇 |
人才学 | 1篇 |
人口学 | 800篇 |
丛书文集 | 33篇 |
理论方法论 | 766篇 |
综合类 | 294篇 |
社会学 | 3652篇 |
统计学 | 1933篇 |
出版年
2023年 | 58篇 |
2021年 | 58篇 |
2020年 | 113篇 |
2019年 | 159篇 |
2018年 | 208篇 |
2017年 | 309篇 |
2016年 | 240篇 |
2015年 | 177篇 |
2014年 | 209篇 |
2013年 | 1492篇 |
2012年 | 328篇 |
2011年 | 238篇 |
2010年 | 205篇 |
2009年 | 179篇 |
2008年 | 218篇 |
2007年 | 194篇 |
2006年 | 158篇 |
2005年 | 212篇 |
2004年 | 179篇 |
2003年 | 220篇 |
2002年 | 237篇 |
2001年 | 227篇 |
2000年 | 205篇 |
1999年 | 192篇 |
1998年 | 150篇 |
1997年 | 119篇 |
1996年 | 129篇 |
1995年 | 107篇 |
1994年 | 99篇 |
1993年 | 108篇 |
1992年 | 127篇 |
1991年 | 117篇 |
1990年 | 115篇 |
1989年 | 109篇 |
1988年 | 113篇 |
1987年 | 110篇 |
1986年 | 103篇 |
1985年 | 124篇 |
1984年 | 98篇 |
1983年 | 106篇 |
1982年 | 79篇 |
1981年 | 76篇 |
1980年 | 72篇 |
1979年 | 74篇 |
1978年 | 78篇 |
1977年 | 54篇 |
1976年 | 45篇 |
1975年 | 59篇 |
1974年 | 48篇 |
1973年 | 42篇 |
排序方式: 共有8758条查询结果,搜索用时 15 毫秒
61.
In the paper we present a new method of calculating sampling intervals, so-called windows, allowing an experimenter some flexibility in timing the sample collection, while a minimum required design efficiency for parameter estimation is assured. The method is based on the Equivalence Theorem for D-optimality what makes the length of each window related to the parameter sensitivities. An example of calculating the windows in a pharmacokinetic study is presented. Some other methods of calculating efficient sampling windows are briefly discussed. 相似文献
62.
To protect public-use microdata, one approach is not to allow users access to the microdata. Instead, users submit analyses to a remote computer that reports back basic output from the fitted model, such as coefficients and standard errors. To be most useful, this remote server also should provide some way for users to check the fit of their models, without disclosing actual data values. This paper discusses regression diagnostics for remote servers. The proposal is to release synthetic diagnostics—i.e. simulated values of residuals and dependent and independent variables–constructed to mimic the relationships among the real-data residuals and independent variables. Using simulations, it is shown that the proposed synthetic diagnostics can reveal model inadequacies without substantial increase in the risk of disclosures. This approach also can be used to develop remote server diagnostics for generalized linear models. 相似文献
63.
经济系统的演化与政策作用 总被引:1,自引:0,他引:1
该文根据耗散结构的基本原理 ,将经济系统划分为平衡态、过渡态和自组织状态。并将政策因素看成是一种外部调控手段 ,分析了在经济系统的不同状态下 ,政策因素对改变系统的结构及变化趋势所起的不同作用 相似文献
64.
该文分析了法国会计模式的特点和影响因素 ,认为法国会计模式与中国会计模式存在相似之处 ,并借鉴法国 1 996年以来会计改革的经验 ,对完善我国会计模式提出了建议 相似文献
65.
James P. McDermott G. Jogesh Babu John C. Liechty Dennis K. J. Lin 《Statistics and Computing》2007,17(4):311-321
We consider the problem of density estimation when the data is in the form of a continuous stream with no fixed length. In
this setting, implementations of the usual methods of density estimation such as kernel density estimation are problematic.
We propose a method of density estimation for massive datasets that is based upon taking the derivative of a smooth curve
that has been fit through a set of quantile estimates. To achieve this, a low-storage, single-pass, sequential method is proposed
for simultaneous estimation of multiple quantiles for massive datasets that form the basis of this method of density estimation.
For comparison, we also consider a sequential kernel density estimator. The proposed methods are shown through simulation
study to perform well and to have several distinct advantages over existing methods. 相似文献
66.
67.
Jason P. Fine David V. Glidden Kristine E. Lee 《Journal of the Royal Statistical Society. Series B, Statistical methodology》2003,65(1):317-329
Summary. We propose a simple estimation procedure for a proportional hazards frailty regression model for clustered survival data in which the dependence is generated by a positive stable distribution. Inferences for the frailty parameter can be obtained by using output from Cox regression analyses. The computational burden is substantially less than that of the other approaches to estimation. The large sample behaviour of the estimator is studied and simulations show that the approximations are appropriate for use with realistic sample sizes. The methods are motivated by studies of familial associations in the natural history of diseases. Their practical utility is illustrated with sib pair data from Beaver Dam, Wisconsin. 相似文献
68.
Katja Kokko Lea Pulkkinen Päivi Mesiäinen Anna-Liisa Lyyra 《The Journal of social issues》2008,64(1):59-76
The aim of this study was to investigate different trajectories of education, based on annual attendance in postcomprehensive and higher education between ages 15 and 42, and their correlates and antecedents. A special focus was on education that occurred after spending several years in the labor market (i.e., off-time education). Analyses were based on the Finnish Jyväskylä Longitudinal Study of Personality and Social Development in which the same participants have been followed from age 8 to 42. Four trajectories were obtained: no or early, off-time, on-time, and continuing education. Through adulthood, career stability, and occupational status were lower among off-time and no or early education participants than among the others. Women on the off-time education trajectory showed an increased level of optimism and achieved identity from age 27 to 42. Both off-time and no or early education participants came from a low socioeconomic (SES) family and had problems in their social behavior at age 8 and school adjustment at age 14. Different types of, and reasons for attending, adult education should be better understood, and adult education should be individually targeted . 相似文献
69.
This article reports an ethnographic study of pre‐school children's social knowledge domains. Results show how the children's shared knowledge concerning social status and social differentiation in the group was strengthened and confirmed during a traditional teacher‐led ring game, where they were supposed to choose a friend. We suggest that from the perspective of the children, the game situation may be understood as, at the same time, a space of participation and an arena for establishing the power order. From the perspective of the teacher, pedagogical intentions may be challenged as they encounter and are mediated and interpreted by children's peer‐cultures. 相似文献
70.
Paul J. E. Miller John P. Caughlin Ted L. Huston 《Journal of marriage and the family》2003,65(4):978-995
This study examined the processes that underlie the association between trait expressiveness and marital satisfaction. A total of 168 newlywed couples participated in a four‐wave, 13‐year longitudinal study of marriage. Cross‐sectional and longitudinal path analyses suggested that expressiveness promotes satisfaction by leading spouses to engage in affectionate behavior and by leading them to idealize their partner. Expressive people formed idealized images of their partner because they brought out the best in their partner's behavior and because they interpreted their partner's behavior in a favorable light. The study extends previous research by showing that the benefits of trait expressiveness extend into the second decade of marriage and by providing a plausible explanation of the connections between trait expressiveness and marital satisfaction. 相似文献