全文获取类型
收费全文 | 4583篇 |
免费 | 600篇 |
国内免费 | 513篇 |
出版年
2024年 | 12篇 |
2023年 | 94篇 |
2022年 | 103篇 |
2021年 | 152篇 |
2020年 | 264篇 |
2019年 | 258篇 |
2018年 | 209篇 |
2017年 | 289篇 |
2016年 | 290篇 |
2015年 | 185篇 |
2014年 | 235篇 |
2013年 | 721篇 |
2012年 | 158篇 |
2011年 | 192篇 |
2010年 | 167篇 |
2009年 | 222篇 |
2008年 | 271篇 |
2007年 | 240篇 |
2006年 | 228篇 |
2005年 | 193篇 |
2004年 | 174篇 |
2003年 | 148篇 |
2002年 | 138篇 |
2001年 | 103篇 |
2000年 | 100篇 |
1999年 | 90篇 |
1998年 | 58篇 |
1997年 | 50篇 |
1996年 | 36篇 |
1995年 | 42篇 |
1994年 | 48篇 |
1993年 | 30篇 |
1992年 | 17篇 |
1991年 | 31篇 |
1990年 | 18篇 |
1989年 | 17篇 |
1988年 | 20篇 |
1987年 | 11篇 |
1986年 | 9篇 |
1985年 | 10篇 |
1984年 | 15篇 |
1983年 | 5篇 |
1982年 | 7篇 |
1981年 | 6篇 |
1980年 | 10篇 |
1979年 | 6篇 |
1978年 | 5篇 |
1977年 | 6篇 |
1976年 | 2篇 |
1975年 | 1篇 |
排序方式: 共有5696条查询结果,搜索用时 15 毫秒
31.
Edward O. Wilson 《Zygon》1990,25(3):245-262
Abstract. The sciences may be conceptualized as a hierarchy ranked by level of organization (e.g., many-body physics ranks above particle physics). Each science serves as an antidiscipline for the science above it; that is, between each pair, tense but creative interplay is inevitable. Biology has advanced through such tension between its subdisciplines and now can serve as an antidiscipline for the social sciences—for anthropology, for example, by examining the connection between cultural and biological evolution; for psychology, by addressing the nature of learning and the structure of the unconscious; for economics, by examining economically irrational behavior and by comparing economic activity in humans and other species. Sociology, concerned mainly with advanced literate societies, is relatively remote from the genetic basis of human social behavior. However, moving between biological and social levels of organization generates richness and points to new and unexpected principles. 相似文献
32.
该文较系统地论述了孟子的普通心理思想。主要问题是:心理学思想的基本观点,知虑心理思想,情欲心理思想,志意心理思想,智能心理思想,性习心理思想。 相似文献
33.
人类颜色视觉的计算理论 总被引:2,自引:0,他引:2
该文有机地结合了计算视觉理论和生态学视觉理论,指出颜色信息处理的根本任务是检测环境中的光不变量。在此基础上,作者提出了颜色视觉的计算理论以及计算理论本身的生物学标准。初级视觉计算是典型的不适定问题,动物的视觉系统则利用视环境中存在的条件将该不适定问题转化为定解问题。本文引入颜色视觉计算的免要条件,客观性约束,以及颜色认知的神经表象,证明了上述约束下颜色算法的存在性。本文给出了构造颜色知觉的基本假设。同时,该文还讨论了与上述问题密切相关的几个基本问题:神经表象的完备性,主观色觉的客观性,明度知觉和颜色知觉的统一,人类主观色觉的实现方式。 相似文献
34.
35.
36.
Arthur Peacocke 《Zygon》1993,28(4):469-484
Abstract. Variable judgments, both negative and positive, have been made by scientists (mainly physicists and astronomers) on the theological implications of their Findings. It is urged that science and theology are most appropriately related through a critical realist approach. On this basis some implications for our conceptions of God and our scientific perspectives on the created world are explored with respect to both divine Being and divine Becoming. A positive assessment of nature as created concludes the article. 相似文献
37.
How do people go about choosing between alternatives in relatively simple settings? This study explores some of the variables that past work suggests may be relevant. Volunteer subjects worked for money in six procedures in which the probability of a payment from either of two alternatives was 1.0, but the rate of pay (i.e. the speed with which a payment was delivered or the size of the payment) interacted with the subjects recent allocation of choices, which we define as the ‘internalities’. Because of the internalities, choosing the currently more profitable alternative did not maximize total earnings. Subjects were more likely to fail to maximize when the interaction between present pay and past choices was spread over longer sequences of choices, or when the reward variable was the speed, rather than the value, of each payment. Subjects often disregarded the internalities and were instead guided by the current yields of the two alternatives, which is a frequently observed tendency, called ‘melioration’, in experiments on choices by animals. The tendency toward melioration was only partially counteracted by explicit instructions on how to maximize earnings. We discuss a theoretical framework for melioration that postulates both motivational and cognitive sources. 相似文献
38.
The present study was designed to investigate visually handicapped students' explanations for failure when the motive to maintain or enhance self-esteem was in conflict with the motive to present a favorable social image. Subjects experienced manipulated failure in a text comprehension task and were subsequently asked to give causal and responsibility attributions in the presence of either a visually handicapped or a non-handicapped experimenter. It was expected that visually disabled participants would claim a handicap-bonus from the non-handicapped experimenter by explicitly presenting non-defensive attributions and accounts as well as handicap-related responses, while defensive explanations should be more pronounced when faced with a blind experimenter. The data provide support for the existence of presumed social expectations as determinants of individuals' verbal self-presentations. 相似文献
39.
Delay-reduction theory states that the effectiveness of a stimulus as a conditioned reinforcer may be predicted most accurately by the reduction in time to primary reinforcement correlated with its onset. We review support for the theory and then discuss two new types of experiments that assess it. One compares models of choice in situations wherein the less preferred outcome is made more accessible; the other investigates whether frequency of conditioned reinforcement affects choice beyond the effect exerted by frequency of primary reinforcement. 相似文献
40.
Momentary maximizing in concurrent schedules with a minimum interchangeover interval 总被引:2,自引:2,他引:0 下载免费PDF全文
Eight pigeons were trained on concurrent variable-interval variable-interval schedules with a minimum interchangeover time programmed as a consequence of changeovers. In Experiment 1 the reinforcement schedules remained constant while the minimum interchangeover time varied from 0 to 200 s. Relative response rates and relative time deviated from relative reinforcement rates toward indifference with long minimum interchangeover times. In Experiment 2 different reinforcement ratios were scheduled in successive experimental conditions with the minimum interchangeover time constant at 0, 2, 10, or 120 s. The exponent of the generalized matching equation was close to 1.0 when the minimum interchangeover time was 0 s (the typical procedure for concurrent schedules without a changeover delay) and decreased as that duration was increased. The data support the momentary maximizing theory and contradict molar maximizing theories and the melioration theory. 相似文献