全文获取类型
收费全文 | 531篇 |
免费 | 426篇 |
国内免费 | 42篇 |
专业分类
999篇 |
出版年
2024年 | 1篇 |
2023年 | 10篇 |
2022年 | 4篇 |
2021年 | 40篇 |
2020年 | 13篇 |
2019年 | 113篇 |
2018年 | 131篇 |
2017年 | 152篇 |
2016年 | 92篇 |
2015年 | 74篇 |
2014年 | 31篇 |
2013年 | 29篇 |
2012年 | 25篇 |
2011年 | 30篇 |
2010年 | 16篇 |
2009年 | 14篇 |
2008年 | 16篇 |
2007年 | 14篇 |
2006年 | 19篇 |
2005年 | 14篇 |
2004年 | 13篇 |
2003年 | 6篇 |
2002年 | 6篇 |
2001年 | 3篇 |
2000年 | 9篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1989年 | 1篇 |
1985年 | 24篇 |
1984年 | 10篇 |
1983年 | 12篇 |
1982年 | 10篇 |
1981年 | 6篇 |
1980年 | 8篇 |
1979年 | 12篇 |
1978年 | 10篇 |
1977年 | 8篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1974年 | 5篇 |
1973年 | 2篇 |
排序方式: 共有999条查询结果,搜索用时 15 毫秒
1.
In a conditioned inhibition paradigm (A+, B+, AX?_, pigeons received either of two keylight stimuli reliably followed by food (A+, B+). However, when one of these keylights was accompanied by another stimulus, food did not follow (AX?). For some groups, the putative inhibitor was a tone, whereas for others it was illumination of a red houselight. The birds pecked the A and B stimuli at a high rate. When X was red houselight, the birds pecked A at a much lower rate in the presence of X. When X was a tone, discrimination between A and AX was much poorer. Moreover, in a transfer test, red houselight inhibited responding to the other keylight, B, but tone did not. These results indicate that red houselight becomes a conditioned inhibitor more quickly than tone in appetitive situations, just as red houselight becomes a conditioned excitor more quickly in those situations. These results contradict the assertion that the latter outcome occurs because red houselight is a stronger appetitive excitor than tone at the start of the experiment (the “head start” hypothesis). 相似文献
2.
Accuracy and laterality of ear preference in repeating 2, 3 and 4 word pairs (WP) of dichotic stimuli in English and French were determined in 80 right-handed subjects (anglophone/francophone, male/female), who were tested in both their native language (L1) and nonnative language (L2). Relative performance accuracy decreased as a function of word pairs per trial (from 2 to 4) as well as language (from L1 to L2). Right-lateral preference in turn increased as a function of WP (from 2 to 4) as well as language (L1 to L2). Right-ear advantage (REA) in L2 decreased as a function of language proficiency (low to high). REA was observed in over 90% of subjects. A rationale for greater lateralization of L2 performance is offered. 相似文献
3.
Four chronic global aphasics were treated with Blissymbols (C. K. Bliss, 1965, Semantography-Blissymbolics, Sydney: Semantography Pub.). As soon as possible the therapeutic communication was based solely on the use of the symbols. Three patients seemed to benefit from therapy. In one case therapy had to be discontinued because of massive perseveration. In one patient expression of needs relied solely on the use of the symbols. In another, expressive speech could be restored to such an extent that communication by the use of symbols was discontinued. 相似文献
4.
Levitt M 《Science and engineering ethics》1997,3(3):305-315
Empirical research with young people in Finland, Germany, Spain and Britain was carried out as part of the BIOCULT project
funded by the European Union. The project focused on their attitudes to biotechnology and, in particular, the formation of
arguments about risk and safety. This paper looks at the responses of 14–18 year olds to a story about the so called anti-obesity
gene, in the form of advice to a friend who is taking it. The majority advised against taking it with some differences by
gender and country. Most reservations were on grounds of safety and the feeling that ‘natural’ ways to lose weight are better:
A minority questioned the idea of striving for a ‘perfect’ body. The types of arguments used by the young people reveal underlying
perspectives on the place of human beings in the world and whether they have a right to manipulate nature and their own bodies.
Marie Levitt is a sociologist with research interests in attitudes and values in relation to biotechnology, health and religion. 相似文献
5.
Game logic and its applications I 总被引:3,自引:0,他引:3
This paper provides a logic framework for investigations of game theoretical problems. We adopt an infinitary extension of classical predicate logic as the base logic of the framework. The reason for an infinitary extension is to express the common knowledge concept explicitly. Depending upon the choice of axioms on the knowledge operators, there is a hierarchy of logics. The limit case is an infinitary predicate extension of modal propositional logic KD4, and is of special interest in applications. In Part I, we develop the basic framework, and show some applications: an epistemic axiomatization of Nash equilibrium and formal undecidability on the playability of a game. To show the formal undecidability, we use a term existence theorem, which will be proved in Part II.The authors thank Hiroakira Ono for helpful discussions and encouragements from the early stage of this research project, and Philippe Mongin, Mitio Takano and a referee of this journal for comments on earlier versions of this paper. The first and second authors are partially supported, respectively, by Tokyo Center of Economic Research and Grant-in-Aids for Scientific Research 04640215, Ministry of Education, Science and Culture.Presented by H. Ono 相似文献
6.
The performances of two groups of retarded spellers (who were equated with respect to the level of deficient performance in spelling, but who differed in the level of phonetic accuracy of their misspellings) at two different age levels were compared to those of normal spellers who had been matched for age and WISC Performance IQ with the retarded spelling groups. The results indicated very marked differences in a number of linguistic skills between the normal spellers and the retarded spellers whose misspellings were characterized by phonetic inaccuracy. The performances of the retarded spellers who produced a preponderance of phonetically accurate misspellings differed markedly from those of the normal spellers only when the task demands involved fairly complex linguistic-cognitive operations. For the most part, the differences among the three groups were in evidence only at the older age level studied. 相似文献
7.
8.
Rats were trained to bar-press for water in the presence of a simultaneous compound tone-light stimulus using a discrete-trial procedure. Different groups were given between 300 and 3900 trials. When subsequently tested in extinction, all rats showed consistent levels of responding to the compound stimulus but responding to the tone and light components declined as a function of number of training trials. This is a demonstration of spontaneous configuring. Two other experiments showed that with similar procedures generalization from a component of the training stimulus to other values on the same continuum decreases with increased training with the compound stimulus. It was concluded that configuring and generalization from a single stimulus involve the same processes. 相似文献
9.
A case of agraphia is documented which resembles in every respect the pattern of results obtained in deep dyslexia. Pronounceable pseudowords could not be written to dictation while concrete nouns were more accurately transcribed than abstract nouns. Verbs and functions words were written very poorly and oral spelling was impaired. In addition, semantic paragraphias were present. In contrast to the deficit observed in writing, no such impairment was found for reading. It is concluded that writing can occur without phoneme-grapheme conversion and that codes generated for reading are functionally distinct from codes generated for writing. 相似文献
10.
Predictions of deficits in children's social problem-solving competencies due to early and continuing father absence were investigated. To test these predictions, equal numbers of father-present and father-absent third graders matched on a number of variables were assessed on measures of social problem-solving performance. In Phase 2 of the study, half of the children from the father-absent category received a 15 week intervention programme which was conducted by adult male trainers to provide structured practice in social problem solving. Results demonstrated that father-absent treatment subjects, compared to father-absent control subjects, improved their social problem-solving skills significantly. Despite improvement due to intervention, social problem-solving scores for father-absent treatment subjects were still below those for father-present control subjects. Educational and developmental implications of the findings were discussed. 相似文献