全文获取类型
收费全文 | 2795篇 |
免费 | 66篇 |
国内免费 | 18篇 |
专业分类
管理学 | 134篇 |
民族学 | 6篇 |
人才学 | 2篇 |
人口学 | 19篇 |
丛书文集 | 82篇 |
理论方法论 | 26篇 |
综合类 | 706篇 |
社会学 | 22篇 |
统计学 | 1882篇 |
出版年
2024年 | 1篇 |
2023年 | 14篇 |
2022年 | 5篇 |
2021年 | 26篇 |
2020年 | 33篇 |
2019年 | 72篇 |
2018年 | 77篇 |
2017年 | 159篇 |
2016年 | 82篇 |
2015年 | 86篇 |
2014年 | 88篇 |
2013年 | 672篇 |
2012年 | 189篇 |
2011年 | 120篇 |
2010年 | 85篇 |
2009年 | 88篇 |
2008年 | 107篇 |
2007年 | 94篇 |
2006年 | 91篇 |
2005年 | 102篇 |
2004年 | 75篇 |
2003年 | 73篇 |
2002年 | 88篇 |
2001年 | 73篇 |
2000年 | 57篇 |
1999年 | 53篇 |
1998年 | 41篇 |
1997年 | 32篇 |
1996年 | 27篇 |
1995年 | 28篇 |
1994年 | 25篇 |
1993年 | 18篇 |
1992年 | 20篇 |
1991年 | 13篇 |
1990年 | 9篇 |
1989年 | 7篇 |
1988年 | 6篇 |
1987年 | 7篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1984年 | 8篇 |
1983年 | 7篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 4篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有2879条查询结果,搜索用时 125 毫秒
941.
线性空间的幂等变换与对合变换的几个等价表示 总被引:1,自引:0,他引:1
给出数域F上线性空间(不一定是有限维的)的线性变换是对合变换与幂等变换的几个等价描述.作为其推论,得到数域F上n阶方阵是对合矩阵与幂等矩阵的几个等价描述. 相似文献
942.
Double hierarchical generalized linear models (with discussion) 总被引:2,自引:0,他引:2
Youngjo Lee John A. Nelder 《Journal of the Royal Statistical Society. Series C, Applied statistics》2006,55(2):139-185
Summary. We propose a class of double hierarchical generalized linear models in which random effects can be specified for both the mean and dispersion. Heteroscedasticity between clusters can be modelled by introducing random effects in the dispersion model, as is heterogeneity between clusters in the mean model. This class will, among other things, enable models with heavy-tailed distributions to be explored, providing robust estimation against outliers. The h -likelihood provides a unified framework for this new class of models and gives a single algorithm for fitting all members of the class. This algorithm does not require quadrature or prior probabilities. 相似文献
943.
Yong B. Lim Jerome Sacks W. J. Studden William J. Welch 《Revue canadienne de statistique》2002,30(1):109-126
To build a predictor, the output of a deterministic computer model or “code” is often treated as a realization of a stochastic process indexed by the code's input variables. The authors consider an asymptotic form of the Gaussian correlation function for the stochastic process where the correlation tends to unity. They show that the limiting best linear unbiased predictor involves Lagrange interpolating polynomials; linear model terms are implicitly included. The authors then develop optimal designs based on minimizing the limiting integrated mean squared error of prediction. They show through several examples that these designs lead to good prediction accuracy. 相似文献
944.
Examining the impact of context on individual‐level outcomes has become an increasingly common undertaking in the social sciences. The growth in concern for identifying the effects of macrolevel characteristics has generated both theoretical and methodological advancements. In this issue of Journal of Marriage and Family, Butler (2002) researches whether the effect of welfare benefit levels on premarital childbearing varies by context, Hoffmann (2002) researches the effect of context on adolescent drug use, and Simons et al. (2002) examine how the relationship between parenting and child conduct varies by context. These articles are used as a background to discuss important theoretical and methodological issues surrounding the analysis of multilevel data. The authors present a simple analysis of data pertaining to age at first marriage taken from the Panel Study of Income Dynamics and merged with census data to measure contextual effects as a pedagogical device for introducing readers to the benefits of multilevel modeling. 相似文献
945.
The authors consider the problem of simple linear regression when the exogenous and endogenous variables are functional and the design is fixed. They propose an estimator for the underlying linear operator and prove its consistency under some conditions which ensure that the design is sufficiently informative. They consider the classical calibration (or inverse regression) problem and analyze a consistent estimator. They also give a simulation study. The proposed method is not hard to implement in practice. 相似文献
946.
讨论信号方向偏离约束方向(即信号方向误差)对线性约束自适应阵性能的影响.把输出信噪比看作是信号方向和输入信噪比的函数,研究了输出信噪比同信号方向和输入信噪比的关系.通过分析,结果发现在一定的输入信噪比下,要求的输出信噪比越大,信号方向误差就应越小;对具有一定方向误差的信号,输入信噪比越大,有用信号受到的抑制就越厉害;当干扰信号存在时,阵对信号方向误差的敏感度减少. 相似文献
947.
Kiyoshi Inoue 《Journal of statistical planning and inference》2003,110(1-2):133-146
The aim of this study is to improve the efficiency of weighted least-squares estimates for a regression parameter. An iterative procedure, starting with an unbiased estimate other than the unweighted least-squares estimate, yields estimates which are asymptotically more efficient than the feasible generalized least-squares estimate when errors are spherically distributed. The result has an application in the improvement of the Graybill–Deal estimate of the common mean of several normal populations. 相似文献
948.
Arthur Renshaw Steven Haberman 《Journal of the Royal Statistical Society. Series C, Applied statistics》2003,52(1):119-137
Summary. The paper presents a reinterpretation of the model underpinning the Lee–Carter methodology for forecasting mortality (and other vital) rates. A parallel methodology based on generalized linear modelling is introduced. The use of residual plots is proposed for both methods to aid the assessment of the goodness of fit. The two methods are compared in terms of structure and assumptions. They are then compared through an analysis of the gender- and age-specific mortality rates for England and Wales over the period 1950–1998 and through a consideration of the forecasts generated by the two methods. The paper also compares different approaches to the forecasting of life expectancy and considers the effectiveness of the Coale–Guo method for extrapolating mortality rates to the oldest ages. 相似文献
949.
《线性代数》课程教学改革的实践与思考 总被引:5,自引:0,他引:5
从线性代数课程的教学现状、内容结构,现行教材的体系为出发点,在课程体系、教学内容等方面提出了在注重经典理论内容的同时,应渗透现在教学的观念、思想和方法.在教学方法和教学手段方面阐明了运用启发式教学方法以及穿透教学手段和多媒体教学手段相结合的意义和作用,提出了一些教学改革的建议. 相似文献
950.