全文获取类型
收费全文 | 6041篇 |
免费 | 327篇 |
国内免费 | 5篇 |
专业分类
6373篇 |
出版年
2024年 | 11篇 |
2023年 | 71篇 |
2022年 | 91篇 |
2021年 | 118篇 |
2020年 | 155篇 |
2019年 | 154篇 |
2018年 | 290篇 |
2017年 | 287篇 |
2016年 | 255篇 |
2015年 | 162篇 |
2014年 | 192篇 |
2013年 | 837篇 |
2012年 | 452篇 |
2011年 | 455篇 |
2010年 | 278篇 |
2009年 | 183篇 |
2008年 | 360篇 |
2007年 | 299篇 |
2006年 | 270篇 |
2005年 | 228篇 |
2004年 | 139篇 |
2003年 | 148篇 |
2002年 | 142篇 |
2001年 | 63篇 |
2000年 | 88篇 |
1999年 | 53篇 |
1998年 | 36篇 |
1997年 | 23篇 |
1996年 | 28篇 |
1995年 | 23篇 |
1994年 | 19篇 |
1993年 | 18篇 |
1992年 | 35篇 |
1991年 | 33篇 |
1990年 | 26篇 |
1989年 | 32篇 |
1988年 | 29篇 |
1987年 | 21篇 |
1986年 | 12篇 |
1985年 | 14篇 |
1984年 | 21篇 |
1983年 | 16篇 |
1982年 | 12篇 |
1979年 | 17篇 |
1978年 | 12篇 |
1976年 | 14篇 |
1974年 | 11篇 |
1970年 | 11篇 |
1968年 | 13篇 |
1965年 | 10篇 |
排序方式: 共有6373条查询结果,搜索用时 0 毫秒
131.
Two predictions derived from Markovits and Barrouillet's (2001) developmental model of conditional reasoning were tested in a study in which 72 twelve-year-olds, 80 fifteen-year-olds, and 104 adults received a paper-and-pencil test of conditional reasoning with causal premises ("if cause P then effect Q"). First, we predicted that conditional premises would induce more correct uncertainty responses to the Affirmation of the consequent and Denial of the antecedent forms when the antecedent term is weakly associated to the consequent than when the two are strongly associated and that this effect would decrease with age. Second, uncertainty responding to the Denial of the antecedent form ("P is not true") should be easier when the formulation of the minor premise invites retrieval of alternate antecedents ("if something other than P is true"). The results were consistent with the hypotheses and indicate the importance of retrieval processes in understanding developmental patterns in conditional reasoning with familiar premises. 相似文献
132.
133.
The authors tested the hypothesis that fans of a sports team avoid private contact with their team when it is unsuccessful (cutting off reflected failure, or CORF), whereas fans actively seek private contact with their team when it is successful (basking in reflected glory, or BIRG). During the 2nd half of the 1999-2000 soccer season, the authors registered the number of visitors who had surfed the Web sites of 16 Belgian and 18 Dutch 1st-division teams on the 1st working day following a championship game. The authors obtained 586 valid measurements, which were transformed into z scores for each team separately. In line with the hypothesis, there were significantly more visitors after the teams won (BIRG) than after they lost (CORF). The effects of game outcome were not mediated by pregame expectations or by the size of the wins or losses. 相似文献
134.
Relationships between frequency of computer use or ability to use the computer effectively with the tendency to construct and process visual mental images were investigated by administering a computer-use questionnaire and a visualization questionnaire to a sample of 185 Italian and Spanish undergraduates. Analysis did not support associations between either (a) frequent computer use of any kind or (b) high competence in using the computer for various purposes and spontaneous use of imagery. 相似文献
135.
Gutiérrez G. de Guzmán I. P. Martínez J. Ojeda-Aciego M. Valverde A. 《Studia Logica》2002,72(1):85-112
The tree-based data structure of -tree for propositional formulas is introduced in an improved and optimised form. The -trees allow a compact representation for negation normal forms as well as for a number of reduction strategies in order to consider only those occurrences of literals which are relevant for the satisfiability of the input formula. These reduction strategies are divided into two subsets (meaning- and satisfiability-preserving transformations) and can be used to decrease the size of a negation normal form A at (at most) quadratic cost. The reduction strategies are aimed at decreasing the number of required branchings and, therefore, these strategies allow to limit the size of the search space for the SAT problem. 相似文献
136.
Forty normal subjects (20 left-handed; 20 right-handed) were submitted to a proprioceptive straight ahead pointing task while blindfolded to study the effect of the hand used and of the hand preference on the estimation of the subjective sagittal middle. Results showed that left-handed and right-handed subjects both deviated to the left of the objective sagittal middle and presented an effect of the hand used and of the starting point affecting their straight ahead performance in a similar way. In all subjects whatever their manual preference, using the left hand and starting 30 degrees to left induced a tendency to deviate to the same side, whereas using the right hand and starting 30 degrees to right induced a tendency to place the subjective middle to the right of the objective middle. These results are interpreted with regard to the hypothesis of a cortical control of the position of the egocentric reference. 相似文献
137.
A generic problem in vision is to know which information drives the perception of a stimulus. We address this problem in a case study that involves the perceptual reversal of an ambiguous image (here, Dali's painting the Slave Market with the Disappearing Bust of Voltaire 1940). In experiment 1, we use 'bubbles' (Gosselin and Schyns, 2001 Vision Research 41 2261-2271) to disambiguate the image and to determine the specific visual information that drives each possible perception (here, the nuns versus the bust of Voltaire). Experiment 2 validates that this information does determine the selective perception of the ambiguous image. We adapted the spatial-frequency channels of observers selectively to the information that mediates one of the two perceptions, to induce the opposite perception of the ambiguous image in a transfer phase. Together, the results suggest a method of revealing the visual information that drives perception. 相似文献
138.
Lists of thematically related words were presented to participants with or without a concurrent task. In Experiments 1 and 2, respectively, English or Spanish word lists were either low or high in concreteness (concrete vs abstract words) and were presented, respectively, auditorily or visually for study. The addition of a concurrent visual or auditory task, respectively, substantially reduced correct recall and doubled the frequency of false memory reports (nonstudied critical or theme words). Divided attention was interpreted as having reduced the opportunity for participants to monitor successfully their elicitations of critical associates. Comparisons of concrete and abstract lists revealed significantly more recalls of false memories for abstract than concrete word lists. Comparisons between two levels of attention, two levels of word concreteness, and two presentation modalities failed to support the "more is less" effect by which enhanced correct recall is accompanied by increased frequencies of false memories. 相似文献
139.
Jezová D Skultétyová I Makatsori A Moncek F Duncko R 《Stress (Amsterdam, Netherlands)》2002,5(3):177-183
Neuroendocrine activation during stress is affected by many factors contributing to the variability of the stress response. The present study was aimed at evaluating long-term changes in hypothalamo-pituitary-adrenocortical (HPA) axis function and in hedonic behavior in adult offspring prenatally stressed by maternal food restriction, with attention on possible gender differences. Adult offspring were blood sampled via a tail artery cannula. Prenatally stressed females had significantly higher adrenal weights compared to males. Plasma ACTH levels, which rose in response to acute stress induced by handling, were significantly higher in females compared to those in males. A similar pattern was found in plasma corticosterone. The rise in ACTH levels was more pronounced in prenatally stressed rats though the rise in corticosterone failed to be modified. Corticotropin releasing hormone (CRH) and proopiomelanocortin mRNA levels in the hypothalamic paraventricular nucleus and anterior pituitary, respectively, were found to be unchanged. The present experiments failed to reveal a decrease in hedonic behavior in prenatally stressed rats. In contrast, in male offspring a tendency to a higher sucrose preference was observed. These data together with observed changes in hormone and CRH mRNA levels indicate that the gestational stress used did not result in a depression-like state in adult offspring. 相似文献
140.
The contextual modulation of conditioned taste aversions by the physical environment and time of day is similar 下载免费PDF全文
Morón I Manrique T Molero A Ballesteros MA Gallo M Fenton A 《Learning & memory (Cold Spring Harbor, N.Y.)》2002,9(5):218-223
In a pair of experiments, we have compared the ability of changes of place (Exp. 1) and changes of time of day (Exp. 2) to separately modulate learned saline-aversion memory phenomena in rats. Neither a spatial nor a temporal change disrupted latent inhibition using the present behavioral procedure. However, pre-exposure to the taste increased the contextual control of the learned aversion expression. The aversion reappeared in the place or at the time of conditioning after extinction in a different context. The results indicate that environmental and temporal contexts can independently, but similarly modulate taste aversion learning. 相似文献