全文获取类型
收费全文 | 12912篇 |
免费 | 218篇 |
专业分类
管理学 | 1659篇 |
民族学 | 54篇 |
人才学 | 1篇 |
人口学 | 1114篇 |
丛书文集 | 79篇 |
教育普及 | 2篇 |
理论方法论 | 1189篇 |
综合类 | 340篇 |
社会学 | 6455篇 |
统计学 | 2237篇 |
出版年
2021年 | 68篇 |
2020年 | 192篇 |
2019年 | 227篇 |
2018年 | 249篇 |
2017年 | 370篇 |
2016年 | 289篇 |
2015年 | 231篇 |
2014年 | 256篇 |
2013年 | 2085篇 |
2012年 | 398篇 |
2011年 | 326篇 |
2010年 | 220篇 |
2009年 | 236篇 |
2008年 | 266篇 |
2007年 | 284篇 |
2006年 | 222篇 |
2005年 | 358篇 |
2004年 | 304篇 |
2003年 | 265篇 |
2002年 | 279篇 |
2001年 | 315篇 |
2000年 | 304篇 |
1999年 | 313篇 |
1998年 | 211篇 |
1997年 | 206篇 |
1996年 | 214篇 |
1995年 | 189篇 |
1994年 | 205篇 |
1993年 | 179篇 |
1992年 | 237篇 |
1991年 | 235篇 |
1990年 | 213篇 |
1989年 | 220篇 |
1988年 | 196篇 |
1987年 | 187篇 |
1986年 | 190篇 |
1985年 | 175篇 |
1984年 | 207篇 |
1983年 | 203篇 |
1982年 | 165篇 |
1981年 | 139篇 |
1980年 | 139篇 |
1979年 | 169篇 |
1978年 | 138篇 |
1977年 | 119篇 |
1976年 | 103篇 |
1975年 | 103篇 |
1974年 | 95篇 |
1973年 | 93篇 |
1971年 | 64篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
D. R. Wingo 《Statistical Papers》1993,34(1):271-276
In a recent paper in this journal, Lee, Kapadia and Brock (1980) developed maximum likelihood (ML) methods for estimating the scale parameter of the Rayleigh distribution from doubly censored samples. They reported convergence difficulties in attempting to solve numerically the nonlinear likelihood equation (LE). To mitigate these difficulties, they employed approximations to simplify the LE, but found that the solution of the resulting simplified equation can give rise to parameter estimates of erratic accuracy. We show that the use of approximations to simplify the LE is unnecessary. In fact, under suitable parametric transformation, the log-likelihood function is strictly concave, the ML estimate always exists, is unique and finite. Furthermore, the LE is easy to solve numerically. A numerical example is given to illustrate the computations involved. 相似文献
42.
A table is presented for the construction and selection of tightened-normal-tightened sampling scheme of type TNT-(n1, n2;c). Efficiency of TNT-(n1, n2;c) scheme over conventional single and double sampling plans is discussed. 相似文献
43.
44.
Margaret R. Somers 《Theory and Society》1994,23(5):605-649
45.
Melissa S. Waters R. Carter Hill William J. Moore Robert J. Newman 《Journal of Labor Research》1994,15(4):355-372
This paper estimates a simultaneous-equations model with public sector bargaining laws and union membership treated as jointly-determined
variables. The extent of public sector unionization has a significant positive influence on the passage of prolabor bargaining
legislation and bargaining legislation has strong, independent effects on the extent of public sector unionization.
We gratefully acknowledge the research support provided by Minbo Kim and Parisun Chantonahom. 相似文献
46.
Chris Dockins Robin R Jenkins Nicole Owens Nathalie B Simon Lanelle Bembenek Wiggins 《Risk analysis》2002,22(2):335-346
This article explores two problems analysts face in determining how to estimate values for children's health and safety risk reductions. The first addresses the question: Do willingness‐to‐pay estimates for health risk changes differ across children and adults and, if so, how? To answer this question, the article first examines the potential effects of age and risk preferences on willingness to pay. A summary of the literature reporting empirical evidence of differences between willingness to pay for adult health and safety risk reductions and willingness to pay for health and safety risk reductions in children is also provided. The second dimension of the problem is a more fundamental issue: Whose perspective is relevant when valuing children's health effects—society's, children's, adults‐as‐children, or parents'? Each perspective is considered, followed ultimately by the conclusion that adopting a parental perspective through an intrahousehold allocation model seems closest to meeting the needs of the estimation problem at hand. A policy example in which the choice of perspective affects the outcome of a regulatory benefit‐cost analysis rounds out the article and emphasizes the importance of perspective. 相似文献
47.
College students (20 women, 14 men) seeking career counseling services at a university career center participated in this exploratory investigation. A 2 (DISCOVER treatment) × 2 (counseling treatment) research design was used to evaluate the individual and combined effects of DISCOVER (ACT, 1998) and counseling on participants' career decision‐making self‐efficacy and career decision‐making attributional style. Findings revealed a significant effect of the use of DISCOVER on participants' career decision‐making self‐efficacy and their sense of control over the career decision‐making process. Results are discussed regarding the implications for career counseling and ideas for further research in this domain. 相似文献
48.
A. Baddeley R. Turner J. Møller M. Hazelton 《Journal of the Royal Statistical Society. Series B, Statistical methodology》2005,67(5):617-666
Summary. We define residuals for point process models fitted to spatial point pattern data, and we propose diagnostic plots based on them. The residuals apply to any point process model that has a conditional intensity; the model may exhibit spatial heterogeneity, interpoint interaction and dependence on spatial covariates. Some existing ad hoc methods for model checking (quadrat counts, scan statistic, kernel smoothed intensity and Berman's diagnostic) are recovered as special cases. Diagnostic tools are developed systematically, by using an analogy between our spatial residuals and the usual residuals for (non-spatial) generalized linear models. The conditional intensity λ plays the role of the mean response. This makes it possible to adapt existing knowledge about model validation for generalized linear models to the spatial point process context, giving recommendations for diagnostic plots. A plot of smoothed residuals against spatial location, or against a spatial covariate, is effective in diagnosing spatial trend or co-variate effects. Q – Q -plots of the residuals are effective in diagnosing interpoint interaction. 相似文献
49.
We discuss the issue of using benchmark doses for quantifying (excess) risk associated with exposure to environmental hazards. The paradigm of low-dose risk estimation in dose-response modeling is used as the primary application scenario. Emphasis is placed on making simultaneous inferences on benchmark doses when data are in the form of proportions, although the concepts translate easily to other forms of outcome data. 相似文献
50.
I. M. Endresen B. Ellertsen C. Endresen A. M. Hjelmen R. Matre H. Ursin 《Work and stress》1991,5(3):217-227
This study concerned the immunological correlates of stress and work. Self reported stress, emotional state, ego-strength, and defensiveness were examined in relation to measures of cellular immunity (T-cell response to Con A and number of T4 and T8 cells) and humoral immunity (concentrations of immunoglobulins and complement components in plasma) in a group of 96 Norwegian female bank employees. The analyses showed that workload, the stress factor with the highest group mean, was associated with number of T-cells, while strain due to body posture during work was related to concentrations of IgM and C3. Further, depression was significantly correlated with IgM concentration and T-cell number, and anxiety with C3 concentration. T-cell activity was the immunological parameter most consistently associated with psychological well-being, showing positive correlations with defensiveness and ego-strength and negative correlations with anxiety and depression. In conclusion, T-cell number and concentrations of IgM and C3 were sensitive to both work-related stress experience and emotional distress. Coping abilities, indicated by the MMPI Ego-strength scale and emotional distress, were reflected in T-cell activity; insufficient coping was associated with low T-cell activity. 相似文献