全文获取类型
收费全文 | 14196篇 |
免费 | 606篇 |
国内免费 | 6篇 |
出版年
2023年 | 80篇 |
2021年 | 141篇 |
2020年 | 251篇 |
2019年 | 282篇 |
2018年 | 389篇 |
2017年 | 365篇 |
2016年 | 424篇 |
2015年 | 292篇 |
2014年 | 378篇 |
2013年 | 1529篇 |
2012年 | 636篇 |
2011年 | 645篇 |
2010年 | 459篇 |
2009年 | 476篇 |
2008年 | 669篇 |
2007年 | 640篇 |
2006年 | 588篇 |
2005年 | 500篇 |
2004年 | 537篇 |
2003年 | 475篇 |
2002年 | 474篇 |
2001年 | 217篇 |
2000年 | 248篇 |
1999年 | 234篇 |
1998年 | 215篇 |
1997年 | 178篇 |
1996年 | 133篇 |
1995年 | 158篇 |
1994年 | 159篇 |
1993年 | 154篇 |
1992年 | 161篇 |
1991年 | 136篇 |
1990年 | 144篇 |
1989年 | 130篇 |
1988年 | 145篇 |
1987年 | 141篇 |
1986年 | 102篇 |
1985年 | 129篇 |
1984年 | 136篇 |
1983年 | 117篇 |
1982年 | 121篇 |
1981年 | 125篇 |
1980年 | 121篇 |
1979年 | 136篇 |
1978年 | 121篇 |
1977年 | 105篇 |
1976年 | 119篇 |
1975年 | 86篇 |
1974年 | 96篇 |
1973年 | 76篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
921.
Numerically small disciplines can be jeopardized by geographic difficulties, if student populations at universities are small and distances between them large. This problem could be addressed, if teaching resources could be shared among several universities and students in several locations could be taught simultaneously. We present the results of a trial in simultaneous Internet and videoconferencing delivery of an introductory cognitive science laboratory. The trial relied on off-the-shelf software and hardware. Students found the delivery nearly as effective as a locally run laboratory, despite a noticeable difference in the level of interactivity between the remote and other, local laboratory classes. We discuss possible further improvements in teaching efficiency and efficacy. 相似文献
922.
Elaina M. Frieda Amanda C. Walley James E. Flege Michael E. Sloane 《Attention, perception & psychophysics》1999,61(3):561-577
Two experiments were conducted to evaluate the perceptual magnet effect. In Experiment 1, Amer-ican English speakers representing diverse dialects were presented with a fine-grained set of stimuli (varying in just noticeable differences forF1 andF2) and indicated whether they heard “/i/” or “not /i/,” thus delimiting the /i/ portion of the vowel space for individual subjects. Then these same subjects selected their own /i/ prototype with a method-of-adjustment procedure. The data from this experiment were used to synthesize customized prototype and nonprototype stimulus sets for Experiment 2. In Experiment 2,24 of our original 37 subjects completed a discrimination task for each of three conditions, in which vector stimuli varied from the subject’s prototype, the nonprototype, or a foreign vowel (/y/) in 15-mel steps. Subjects displayed higher discrimination, as indexed byd′, for the nonprototype condition than they did for both the prototype and the foreign conditions. In addition, discrimination was better for variants further away from the referent in each condition. However, discrimination was not especially poor for stimuli close to subjects’ individual prototypes—a result that would have yielded the strongest support for the operation of a magnet effect. This negative finding, together with other aspects of our results, raises problems for any theory of vowel perception that relies solely on “one-size-fits-all” prototype representations. 相似文献
923.
Viewed from the center of projection, a perspective picture presents the pictorial depth information of a scene. Knowing the center of projection, one can reconstruct the depicted scene. Assuming another viewpoint is the center of projection will cause one to reconstruct a transformed scene. Despite these transformations, we appreciate pictures from other viewpoints. The compensation hypothesis states that the visible picture surface allows observers to compensate for transformations by locating the center of projection and experiencing pictorial space from there. We show that observers neither completely compensate for nor experience transformations of space as geometry would predict. We propose a modified compensation hypothesis according to which different degrees of visibility of the picture surface invoke different degrees of compensation. 相似文献
924.
925.
Memory for previously learned figural sequences and item-to-item covariations within figural sequences was examined under explicit and implicit instructional conditions in three age groups: young adults (17-23 years); middle-aged adults (35-45 years); and older adults (55-65 years). In Phase 1 of the experiment, the acquisition phase, half the subjects in each age group learned sequences of three to eight items in which the item-to-item changes conformed to an artificial grammar, and the other half of the subjects in each age group learned strings in which the item-to-item changes were nongrammatical. In Phase 2, the implicit/explicit test phase, subjects made forced-choice judgments about parts of the strings that they learned in Phase 1, under either explicit or implicit instructions. Analyses of Phase 2 data revealed that subjects in both instructional conditions used item-to-item covariations in making decisions about grammatical strings. However, use of previously learned covariations as well as the number of correct judgments about previously learned strings was greater in the explicit condition than in the implicit condition. An age-related deficit was found for explicit recognition of grammar-following sequences. 相似文献
926.
This research investigates preferences and judgments under ambiguous vs conflicting information. Three studies provided evidence for two major hypotheses: (1) Conflicting messages from two equally believable sources are dispreferred in general to two informatively equivalent, ambiguous, but agreeing messages from the same sources (i.e., conflict aversion); and (2) conflicting sources are perceived as less credible than ambiguous sources. Studies 2 and 3 yielded evidence for two framing effects. First, when the outcome was negative, subjects' preferences were nearly evenly split between conflict and ambiguity, whereas a positive outcome produced marked conflict aversion. Second, a high probability of a negative outcome or a low probability of a positive one induced conflict preference. However, no framing effects were found for source credibility judgments. Study 3 also investigated whether subject identification with a source might affect preferences or credibility judgments, but found no evi dence for such an effect. The findings suggest cognitive and moti vational explanations for conflict aversion as distinct from ambi guity aversion. The cognitive heuristic is that conflict raises suspicions about whether the sources are trustworthy or credi ble. The motivational explanation stems from that idea that if sources disagree, then the judge not only becomes uncertain but also must disagree with at least one of the sources, whereas if the sources agree then the judge may agree with them and only has to bear the uncertainty. 相似文献
927.
Georg H. Eifert Michael J. Zvolensky John T. Sorrell Derek R. Hopko C. W. Lejuez 《Journal of psychopathology and behavioral assessment》1999,21(4):293-305
The purpose of this study was to examine the extent to which anxiety-related individual difference variables predict anxious responding when individuals experience aversive bodily sensations. Thus, we explore several psychological and behavioral predictors of response to a single 25-sec inhalation of 20% carbon dioxide-enriched air in 70 nonclinical participants. Predictor variables included anxiety sensitivity, suffocation fear, heart-focused anxiety, and breath-holding duration. Multiple regression analyses indicated that only anxiety sensitivity significantly predicted postchallenge panic symptoms, whereas both anxiety sensitivity and suffocation fear predicted postchallenge anxiety. These data are in accord with current models of panic disorder that emphasize the role of fear of fear in producing heightened anxiety and panic symptoms and help clarify specific predictors of anxiety-related responding to biological challenge. 相似文献
928.
Michael Clark 《Ratio》1999,12(1):1-13
Was Luther avowing a genuine moral incapacity when he claimed that he could do no other? Bernard Williams has distinguished moral from psychological incapacity in terms of deliberation. There are three particular difficulties for the notion: in addition to (1) scepticism about whether the agent is genuinely incapable, there are (2) the possibility of conflicting moral incapacities, and (3) apparent cases where there is no actual or possible deliberation. If (1) can be countered, (2) can be met by ceteris paribus clauses, and it is shown that these do not remove the element of necessity. And (3) can be met by showing how possible deliberation is involved in putative counter-examples. Williams' account needs to be augmented to deal with cases of the morally unthinkable, and refined to allow for incipient attempts to do the morally impossible 相似文献
929.
Christopher D. Ratcliff Michael Czuchry Nikki C. Scarberry Jennifer C. Thomas Donald F. Dansereau Charles G. Lord 《Journal of applied social psychology》1999,29(5):994-1009
An important application of psychological principles involves increasing intentions to engage in activities that, although admittedly beneficial, are often not initially appealing (e.g., studying, quitting smoking, dieting). The present study tests the utility of directed thinking as a tool for eliciting intentions to engage in such activities. Undergraduate students were directed to think either about the reasons why people should find studying enjoyable or about the actions that people might take to make studying enjoyable. Regardless of whether they thought as individuals or in cooperating dyads, students who thought about actions later reported greater intentions to spend time studying than did students who thought about reasons. The results have both theoretical and practical significance. 相似文献
930.