全文获取类型
收费全文 | 11844篇 |
免费 | 420篇 |
专业分类
管理学 | 1525篇 |
民族学 | 82篇 |
人才学 | 1篇 |
人口学 | 1225篇 |
丛书文集 | 42篇 |
理论方法论 | 1054篇 |
综合类 | 417篇 |
社会学 | 5241篇 |
统计学 | 2677篇 |
出版年
2023年 | 101篇 |
2022年 | 91篇 |
2021年 | 122篇 |
2020年 | 267篇 |
2019年 | 311篇 |
2018年 | 508篇 |
2017年 | 600篇 |
2016年 | 481篇 |
2015年 | 307篇 |
2014年 | 394篇 |
2013年 | 2089篇 |
2012年 | 653篇 |
2011年 | 393篇 |
2010年 | 318篇 |
2009年 | 281篇 |
2008年 | 317篇 |
2007年 | 276篇 |
2006年 | 222篇 |
2005年 | 259篇 |
2004年 | 233篇 |
2003年 | 266篇 |
2002年 | 273篇 |
2001年 | 252篇 |
2000年 | 225篇 |
1999年 | 204篇 |
1998年 | 161篇 |
1997年 | 131篇 |
1996年 | 144篇 |
1995年 | 116篇 |
1994年 | 110篇 |
1993年 | 112篇 |
1992年 | 141篇 |
1991年 | 126篇 |
1990年 | 119篇 |
1989年 | 110篇 |
1988年 | 116篇 |
1987年 | 115篇 |
1986年 | 106篇 |
1985年 | 125篇 |
1984年 | 99篇 |
1983年 | 108篇 |
1982年 | 77篇 |
1981年 | 74篇 |
1980年 | 71篇 |
1979年 | 77篇 |
1978年 | 78篇 |
1977年 | 56篇 |
1976年 | 46篇 |
1975年 | 61篇 |
1974年 | 50篇 |
排序方式: 共有10000条查询结果,搜索用时 321 毫秒
871.
ABSTRACTIt is time for action by leaders across higher education to strengthen quality improvement (QI) in college health, in pursuit of better care, better health, and increased value – goals closely linked to students' learning and success. The size and importance of the college student population; the connections between wellbeing, and therefore QI, and student success; the need for improved standards and greater accountability; and the positive contributions of QI to employee satisfaction and professionalism all warrant a widespread commitment to building greater capacity and capability for QI in college health. This report aims to inspire, motivate, and challenge college health professionals and their colleagues, campus leaders, and national entities to take both immediate and sustainable steps to bring QI to the forefront of college health practice – and, by doing so, to elevate care, health, and value of college health as a key pathway to advancing student success. 相似文献
872.
A. C. Braga L. Costa P. Oliveira 《Journal of Statistical Computation and Simulation》2013,83(2):307-325
In this paper, an alternative method for the comparison of two diagnostic systems based on receiver operating characteristic (ROC) curves is presented. ROC curve analysis is often used as a statistical tool for the evaluation of diagnostic systems. However, in general, the comparison of ROC curves is not straightforward, in particular, when they cross each other. A similar difficulty is also observed in the multi-objective optimization field where sets of solutions defining fronts must be compared with a multi-dimensional space. Thus, the proposed methodology is based on a procedure used to compare the performance of distinct multi-objective optimization algorithms. In general, methods based on the area under the ROC curves are not sensitive to the existence of crossing points between the curves. The new approach can deal with this situation and also allows the comparison of partial portions of ROC curves according to particular values of sensitivity and specificity of practical interest. Simulations results are presented. For illustration purposes, considering real data from newborns with very low birthweight, the new method was applied in order to discriminate the better index for evaluating the risk of death. 相似文献
873.
874.
875.
876.
Most of the usual multivariate methods have been extended to the context of functional data analysis. Our contribution concerns the study of sliced inverse regression (SIR) when the response variable is real but the regressor is a function. In the first part, we show how the relevant properties of SIR remain essentially the same in the functional context under suitable conditions. Unfortunately, the estimation procedure used in the multivariate case cannot be directly transposed to the functional one. Then, we propose a solution that overcomes this difficulty and we show the consistency of the estimates of the parameters of the model. 相似文献
877.
A multivariate modified histogram density estimate depending on a reference density g and a partition P has been proved to have good consistency properties according to several information theoretic criteria. Given an i.i.d. sample, we show how to select automatically both g and P so that the expected L 1 error of the corresponding selected estimate is within a given constant multiple of the best possible error plus an additive term which tends to zero under mild assumptions. Our method is inspired by the combinatorial tools developed by Devroye and Lugosi [Devroye, L. and Lugosi, G., 2001, Combinatorial Methods in Density Estimation (New York, NY: Springer–Verlag)] and it includes a wide range of reference density and partition models. Results of simulations are also presented. 相似文献
878.
879.
Carl Rodrigue Francine Lavoie Barry D. Adam Marie-France Goyer Céline Magontier 《Journal of sex research》2013,50(9):1192-1205
Research on casual sexual relationships (CSRs) among emerging adults is prevalent, yet our empirical and theoretical knowledge of relationship processes involved in these relationships is limited. The present study’s objective was to compare four CSR partner types (acquaintance, friend, non-dating partner, ex-romantic partner) on passion, intimacy, and commitment, the components of Sternberg’s triangular theory of love. A total of 441 Canadians aged 18–25 years who were not in a romantic relationship, and who reported having had more than one sexual contact with their last CSR partner, completed an online survey. Across all partner types, passion was highest, followed by intimacy and commitment. Levels of passion, intimacy, and commitment generally increased with partner familiarity. However, CSR partner type differences on the three components were partially explained by CSR components (i.e., frequency of sexual activity, frequency of social activity, whether partners saw each other with the main goal of having sex, sexual exclusivity agreement, and hopes about the relationship). Results are consistent with CSRs’ emphasis on sexuality, and, to a lesser extent, emotions. However, they challenge the mainstream and scientific conflation of CSRs with an absence of emotional bond, commitment, or love. 相似文献
880.
Twenty Asperger’s Syndrome (AS) participants were compared with 20 matched neurotypical controls in their decoding of postural
cues of boredom, interest, and disagreement. On a nonverbal matching task, the AS group performed as accurately as the controls,
whereas on a verbal labeling task, AS participants made significantly more mistakes in labeling bored postures. Response times
of the AS group were significantly slower than controls in their judgments of all three attitudes on both tasks, with the
exception only of disagreeing postures on the verbal labeling task. It was hypothesized that these slower response times may
reflect a feature-based cognitive processing style by AS participants. Proposed practical recommendations are to train AS
individuals in the recognition of boredom, and to improve the speed with which they can recognize different attitudes. 相似文献