全文获取类型
收费全文 | 23974篇 |
免费 | 188篇 |
国内免费 | 2篇 |
专业分类
24164篇 |
出版年
2023年 | 40篇 |
2021年 | 51篇 |
2020年 | 96篇 |
2019年 | 109篇 |
2018年 | 3577篇 |
2017年 | 2900篇 |
2016年 | 2337篇 |
2015年 | 283篇 |
2014年 | 164篇 |
2013年 | 486篇 |
2012年 | 698篇 |
2011年 | 2518篇 |
2010年 | 2591篇 |
2009年 | 1547篇 |
2008年 | 1816篇 |
2007年 | 2285篇 |
2006年 | 148篇 |
2005年 | 287篇 |
2004年 | 255篇 |
2003年 | 173篇 |
2002年 | 129篇 |
2001年 | 166篇 |
2000年 | 185篇 |
1999年 | 104篇 |
1998年 | 48篇 |
1997年 | 63篇 |
1996年 | 41篇 |
1994年 | 25篇 |
1992年 | 47篇 |
1991年 | 66篇 |
1990年 | 62篇 |
1989年 | 52篇 |
1988年 | 51篇 |
1987年 | 38篇 |
1986年 | 32篇 |
1985年 | 33篇 |
1984年 | 35篇 |
1983年 | 29篇 |
1982年 | 34篇 |
1981年 | 32篇 |
1979年 | 30篇 |
1978年 | 22篇 |
1977年 | 25篇 |
1976年 | 31篇 |
1975年 | 27篇 |
1974年 | 32篇 |
1973年 | 25篇 |
1971年 | 22篇 |
1968年 | 25篇 |
1967年 | 24篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
241.
We apply the 'patchwork engine' (PE; van Tonder and Ejima, 2000 Neural Networks forthcoming) to encode spaces between textons in an attempt to find a suitable feature representation of anti-textons [Williams and Julesz, 1991, in Neural Networks for Perception volume 1: Human and Machine Perception Ed. H Wechsler (San Diego, CA: Academic Press); 1992, Proceedings of the National Academy of Sciences of the USA 89 6531-6534]. With computed anti-textons it is possible to show that tessellation and distribution of anti-textons can differ from that of textons depending on the ratio of texton size to anti-texton size. From this we hypothesise that variability of anti-textons can enhance texture segregation, and test our hypothesis in two psychophysical experiments. Texture segregation asymmetry is the topic of the first test. We found that targets on backgrounds with regular anti-textons segregate more strongly than on backgrounds with highly variable anti-textons. This neatly complements other explanations for texture segregation asymmetry (e.g. Rubenstein and Sagi, 1990 Journal of the Optical Society of America A 7 1632-1643). Second the relative significance of textons and anti-textons in human texture segregation is investigated for a limited set of texture patterns. Subjects consistently judged a combination of texton and anti-texton gradients as more conspicuous than texton-only gradients, and judged texton-only gradients as being more conspicuous than anti-texton-only gradients. In the absence of strong texton gradients the regularity versus irregularity of anti-textons agrees with perceived texture segregation. Using PE outputs as anti-texton features thus enabled the conception of various useful tests on texture segregation. The PE is originally intended as a general image segmentation method based on symmetry axes. With this paper we therefore hope to relate anti-textons with visual processing in a wider sense. 相似文献
242.
The current article suggests a possible synthesis of Skinner's (1957) treatment of verbal behavior with the more recent behavioral interpretation of language known as relational frame theory. The rationale for attempting to combine these two approaches is first outlined. Subsequently, each of the verbal operants described by Skinner is examined and subjected to a relational frame analysis. In each case, two types of operants are identified; one based on direct contingencies of reinforcement and the other based on arbitrarily applicable relational responding. The latter operants are labeled verbal because they can be distinguished from other forms of social behavior, and they appear to possess the symbolic or referential qualities often ascribed to human language. By applying relational frame theory to Skinner's verbal operants, we aim to contribute towards the development of a modern behavior-analytic research agenda in human language and cognition. 相似文献
243.
Robert E. Lee Kathleen Burns Jager Jason B. Whiting Catherine T. Kwantes 《Contemporary Family Therapy》2000,22(1):81-90
Confirmatory factor analysis and regression analyses of the Beavers Interactional Scales did not appear to support the model offered by its developers, namely, several specified family attributes contributing respectively to two global factors of Family Competence and Family Style. Moreover, regression analysis indicated that only three of 12 items predicted raters' assessments of Global Family Health, and one of seven items predicted Global Family Style. Individuals interested in the family dynamic centripetal/centrifugal might best think of that as a unitary entity and rate it accordingly. 相似文献
244.
The measurement properties of the Center for Epidemiologic Studies--Depression Scale (CES-D; L. S. Radloff, 1977) were evaluated in a probability sample of homeless adults residing in a large and demographically diverse community. The findings from this investigation suggest that the CES-D is a reliable measure of depressive symptoms among homeless adults and that the factor structure of the scale replicates the factor structure found in the general population. Change in the CES-D scores was associated with change in residential status, with participants who had made a transition from homelessness to regular domicile, reporting significantly lower levels of depressive symptomatology. This result indicates the scale's sensitivity to current depressive mood, as affected by significant life events encountered by homeless persons. 相似文献
245.
Samuel D. Kron 《Journal of religion and health》1968,7(4):333-341
246.
247.
248.
This paper outlines the ways in which an individual’s notions of sexuality are challenged by immigration. It describes four basic facets of sexuality and the ways in which each are rooted in culture. These include (1) the relative importance of sexuality in daily life; (2) potential or overt homosexuality; (3) marriage—whether based on arrangement or love; and (4) cross-cultural romantic and marital relationships. Immigration can stir up conflicts in each of these realms and lead to defensive retreat into familiar customs or a counterphasic plunge into new cultural avenues. Ideally, it would lead to a working-through of these conflicts and subsequent growth in the immigrant’s understanding of his or her sexual self. 相似文献
249.
Deane-Peter Baker 《International Journal for Philosophy of Religion》2005,57(2):77-103
Alvin Plantingas Warranted Christian Belief is without questionone of the central texts of the Reformed epistemology movement. Critiques of Plantingas defence have been both multiple and varied. As varied as these responses are, however, it is my contention that many of them amount to the same thing. It is the purpose of this paper to offer an overview of the main lines of attack that have been directed as Plantingas project, and thereafter to show how many, if not most, of these objections can be understood as versions or aspects of the same criticism, what I call the Inadequacy Thesis. 相似文献
250.
This article examines how between-individual comparisons influence performance evaluations in rating tasks. The authors demonstrated a systematic change in the perceived difference across ratees as a result of changing the way performance information is expressed. Study 1 found that perceived performance difference between 2 individuals was greater when their objective performance levels were presented with small numbers (e.g., absence rates of 2% vs. 5%) than when they were presented with large numbers (e.g., attendance rates of 98% vs. 95%). Extending this finding to situations involving trade-offs between multiple performance attributes across ratees, Study 2 showed that the relative preference for 1 ratee over another actually reversed when the presentation format of the performance information changed. The authors draw upon prospect theory to offer a theoretical framework describing the between-individual comparison aspect of performance evaluation. 相似文献