全文获取类型
收费全文 | 1580篇 |
免费 | 144篇 |
专业分类
管理学 | 66篇 |
民族学 | 5篇 |
人口学 | 39篇 |
丛书文集 | 30篇 |
理论方法论 | 102篇 |
综合类 | 172篇 |
社会学 | 55篇 |
统计学 | 1255篇 |
出版年
2024年 | 1篇 |
2023年 | 4篇 |
2022年 | 3篇 |
2021年 | 15篇 |
2020年 | 14篇 |
2019年 | 58篇 |
2018年 | 65篇 |
2017年 | 33篇 |
2016年 | 45篇 |
2015年 | 50篇 |
2014年 | 72篇 |
2013年 | 241篇 |
2012年 | 67篇 |
2011年 | 83篇 |
2010年 | 63篇 |
2009年 | 141篇 |
2008年 | 113篇 |
2007年 | 135篇 |
2006年 | 22篇 |
2005年 | 13篇 |
2004年 | 17篇 |
2003年 | 22篇 |
2002年 | 9篇 |
2001年 | 16篇 |
2000年 | 18篇 |
1999年 | 7篇 |
1998年 | 9篇 |
1997年 | 8篇 |
1996年 | 14篇 |
1995年 | 31篇 |
1994年 | 21篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1988年 | 2篇 |
1986年 | 2篇 |
1985年 | 39篇 |
1984年 | 54篇 |
1983年 | 45篇 |
1982年 | 46篇 |
1981年 | 34篇 |
1980年 | 26篇 |
1979年 | 21篇 |
1978年 | 38篇 |
1977年 | 4篇 |
1976年 | 1篇 |
排序方式: 共有1724条查询结果,搜索用时 15 毫秒
101.
Employing certain generalized random permutation models and a general class of linear estimators of a finite population mean, it is shown that many of the conventional estimators are “optimal” in the sense of minimum average mean square error. Simple proofs are provided by using a well-known theorem on UMV estimation. The results also cover certain simple response error situations. 相似文献
102.
A projective (2n,n,λ,1)-design is a set of n element subsets (called blocks) of a 2n-element set V having the properties that each element of V is a member of λ blocks and every two blocks have a non-empty intersection. This paper establishes existence and non-existence results for various projective (2n,n,λ,1)-designs and their subdesigns. 相似文献
103.
Harold Sackrowitz 《Journal of statistical planning and inference》1982,6(3):287-296
The problem is that of estimating the probabilities of m independent binomial random variables when their probabilities are known to be nondecreasing and the loss function is squared error. In the cases where the m.l.e. is inadmissible (essentially when the total number of trials is 7 or more) we present a method for modifying the m.l.e. to get a better estimator. The method requires a series of changes. At each step we alter the action taken by the m.l.e. on each of three, appropriately chosen, points in the sample space. 相似文献
104.
V.K. Srivastava 《Journal of statistical planning and inference》1982,6(3):297-299
This paper presents a class of estimators for the mean of a normal population and determines the conditions on characterizing scalars under which the class of estimators uniformly dominates over the conventional sample mean according to the mean-square-error criterion. 相似文献
105.
We analyse post-war Dutch migration to New Zealand. We document that history, reflect on analytical and econometric modelling and then combine a sample of Dutch migrants in New Zealand with a representative sample of Dutch in The Netherlands to estimate wage equations and the determinants of the migration decision. We use the results for ex post evaluation of the migration decision.Joop Hartog is Fellow of IZA (Bonn), CESifo (München), AIAS and Tinbergen Institute (Amsterdam). Work on this project was begun when Hartog was Erskine Visitor at the University of Canterbury, Christchurch New Zealand. Rainer Winkelmann is Fellow of CEPR and IZA (Bonn). This paper is produced as part of a CEPR research programme on European Migration from Economic Analysis to Policy Response, supported by a grant from the Commission of the European Communities under its Human Capital and Mobility Programme (no. ERBCHRXCT940515).It was presented at the European Society for Population Economics meetings in Bonn, June 2000. We gratefully acknowledge comments by Justin Lee Tobias, Jacques Poot, Ed Vytlacil, an anonymous referee and Paul Schultz. Responsible editor: T. Paul Schultz. 相似文献
106.
In quality control, a performance variable having a two-sided specification limit is common for assessing lot quality. Sometimes it is difficult or impossible to measure the performance variable directly; for example, when testing is destructive, expensive, or when the performance variable is related to the lifetime of the product. However, it may happen that there are several concomitant variables which are easily measured and which correlate highly with the variable of interest. Thus, one may use measurements on these variables to select or screen product which will have a high conditional probability of meeting product specification. We consider this situation when all variables have a joint multivariate normal distribution and the specification limits on the performance variable are two-sided. 相似文献
107.
本文提出,小学阶段的启蒙教育,对人才的培养具有特别重要的意义,应特别注意小学教师素质的培养。 相似文献
108.
张勇 《吉林师范大学学报》2007,35(4):37-39
本文针对高师本科小学教育专业英语方向的教学法课程在实际教学过程中存在的不足,提出了改进的建议:丰富知识内容,增加《英语课程标准》、课堂教学用语、英文书写及一线教学现状的内容;加强技能训练,从加强教学基本功训练和加强课堂教学模拟训练两方面人手;培养科研能力,通过分析教学案例、开展专题研讨和撰写小型论文的方式进行培养。 相似文献
109.
A dynamic model of a heterogeneous population is studied. Particles belonging to a population are divided, at every time t, into a finite number of classes according to their types and the partition changes over time. The role of the occupancy numbers, namely the cardinality of each class, is highlighted. The relationship between the stochastic process of occupancy numbers and the process of particle types is analyzed. The main goal of this paper is the estimation of the lifetime of each particle at a given time t, when the observed data are the history of the process of the number of dead particles up to t. Furthermore, a discrete time approximation of the filter is given. 相似文献
110.
The relative performance of a component of a series system in two different environments is considered. The conditional probability of the failure of the system due to the failure of the specified component given that the system failed before time t is regarded as a measure of relative importance of the component to the system. A U-statistic test for checking the equality of the relative importance of the component to the system in two different environments against the alternative that the relative importance is smaller in one of the environments, is proposed. Some simulation results for estimating the power of the test are reported. The proposed test is applied to one real data set and it is seen that a different aspect of the data is brought out by this comparison than that by the comparisons of the absolute importance functions such as the subsurvival functions, considered in earlier studies. 相似文献