全文获取类型
收费全文 | 62019篇 |
免费 | 769篇 |
国内免费 | 6篇 |
专业分类
62794篇 |
出版年
2020年 | 448篇 |
2019年 | 586篇 |
2018年 | 3989篇 |
2017年 | 3363篇 |
2016年 | 2968篇 |
2015年 | 780篇 |
2014年 | 794篇 |
2013年 | 3609篇 |
2012年 | 1866篇 |
2011年 | 3552篇 |
2010年 | 3206篇 |
2009年 | 2301篇 |
2008年 | 2777篇 |
2007年 | 3224篇 |
2006年 | 1167篇 |
2005年 | 1190篇 |
2004年 | 1115篇 |
2003年 | 1045篇 |
2002年 | 1015篇 |
2001年 | 1242篇 |
2000年 | 1279篇 |
1999年 | 946篇 |
1998年 | 513篇 |
1997年 | 474篇 |
1996年 | 454篇 |
1995年 | 457篇 |
1994年 | 434篇 |
1992年 | 778篇 |
1991年 | 728篇 |
1990年 | 689篇 |
1989年 | 662篇 |
1988年 | 661篇 |
1987年 | 606篇 |
1986年 | 609篇 |
1985年 | 677篇 |
1984年 | 582篇 |
1983年 | 568篇 |
1982年 | 475篇 |
1981年 | 430篇 |
1980年 | 423篇 |
1979年 | 610篇 |
1978年 | 487篇 |
1977年 | 461篇 |
1976年 | 469篇 |
1975年 | 511篇 |
1974年 | 583篇 |
1973年 | 612篇 |
1972年 | 508篇 |
1968年 | 500篇 |
1967年 | 428篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
911.
The notion that verbal ability is related to mental processing speed was examined using tasks that systematically varied in semantic content. Subjects' reaction times were measured in five tasks involving arrow matching, physical identity word matching, or taxonomic identity word matching. The findings indicated that matching tasks using different decision rules and different stimuli were all related to verbal ability. In fact, reaction time for subjects required to judge whether two arrows pointed in the same direction was the best predictor of verbal ability. One explanation of the results is that speed of information processing (a general factor) may be the important component of verbal ability which is measured by seemingly different matching tasks. 相似文献
912.
913.
Previous research has shown that perceived odor strength does not vary with flow rate of an odorant vapor entering the naris when that variation is produced by subject-controlled changes in sniff pressure, but that it does vary with flow rate when the variation is produced by experimenter-controlled changes in the resistance of the olfactometric system. We have suggested an odor-constancy model in which invariance of perceived odor strength is linked to perceived effort of sniffing, and have hypothesized that changed resistance will have its effect because there is no corresponding change in perceived effort when sniff pressure is held constant. In two studies, subjects made magnitude estimations of the perceived effort of sniffing; sniff pressure was controlled by having the subject match his sniff, displayed on a storage oscilloscope face, to a pattern specifying its required shape, duration, and level. In Experiment 1, resistance was fixed while sniff pressure varied; perceived effort grew as the .8 power of the required sniff pressure. In Experiment 2, sniff pressure and resistance were varied in a factorial design; perceived effort grew as the .8 power of pressure at fixed resistance, but remained unchanged when resistance varied at fixed pressure. This outcome provides indirect support for the odor-constancy model, since it shows that perceived effort covaries with flow rate under the condition in which constancy is found but does not change under the condition in which constancy fails. 相似文献
914.
Proctor (1981) presented a theoretical framework that distinguishes factors contributing to disparities in time to classify physical-same, name-same, and different letter pairs as a function of three variables: method of presentation (simultaneous vs. successive), case relationship (samecase vs. opposite-case pairs), and blocking (blocked vs. mixed presentation of same-case and opposite-case pairs). He also argued that these variables were critical in multIletter matches, and performed a between-study comparison of existing data to support his contention. Because comparison across studies is always a tenuous process and because the absence of several relevant conditions precluded a complete analysis of predictions, a within-experiment manipulation of the three relevant variables was desirable. The present study reports such an experiment. In general, the factorial manipulation of variables supported predictions of Proctor’s framework and indicated that many phenomena of multiletter matching, including the widely studied fast-“same” phenomenon, are attributable primarily to differences in the rate at which component letter pairs are matched. 相似文献
915.
James P. Cunningham Lynn A. Cooper Celia C. Reaves 《Attention, perception & psychophysics》1982,32(1):50-60
In the first experiment, in which two successively presented free-form visual patterns varied in their similarity to each other, subjects had to decide, in one condition, if the patterns were “identical” and in two other conditions if the patterns were “similar.” Qualitative individual differences in the effect of similarity on the time required to make a decision were found in the “identity” condition, and these differences interacted with the “similarity” conditions. The individual differences and the experimental effects are interpreted in terms of a two-process model of the visual comparison process—a holistic matching process that is sometimes accompanied by an analytic difference detection process. In the second experiment, the same subjects repeatedly categorized subsets of the free-form visual patterns on the basis of similarity. There appeared to be no individual differences in the subjects’ perceptions of similarity, but subjects’ perceptions did differ from the assumptions made by the experimenters when they established the response criteria for the first experiment. 相似文献
916.
The correspondence between subjective and neural response to change in acoustic intensity was considered by deriving power functions from subjective loudness estimations and from the amplitude and latency of auditory brainstem evoked response components (BER). Thirty-six subjects provided loudness magnitude estimations of 2-sec trains of positive polarity click stimuli, 20/sec, at intensity levels ranging from 55 to 90 dB in 5-dB steps. The loudness power function yielded an exponent of .48. With longer trains of the same click stimuli, the exponents of BER latency measures ranged from -.14 for wave I to -.03 for later waves. The exponents of BER amplitude-intensity functions ranged from .40 to .19. Although these exponents tended to be larger than exponents previously reported, they were all lower than the exponent derived from the subjective loudness estimates, and a clear correspondence between the exponents of the loudness and BER component intensity functions was not found. 相似文献
917.
918.
A behaviorally-oriented activities therapy program was designed and implemented with adolescents who manifested problems in school, at home, and with peers. Baseline measures for target behaviors were taken within the activities therapy program and, after a behavioral analysis, specific techniques were chosen to remediate problems. Techniques employed included: contingency contracting, assertiveness training, relaxation training, and cognitive restructuring. Evaluation of the effectiveness of each program was performed through daily measurement of the frequency of the occurrence of the target behaviors. Three case studies are presented which are illustrative of the range of programs which can be successfully implemented with this population. 相似文献
919.
The test-retest reliability of alcohol abusers' self-reports of their daily drinking and daily drinking, alcohol-related incarcerations and their drinking problem history were highly reliable (r = +0.79 to +0.98). Limits on the generalizability of these finclings are discussed. ing dispositions for the 360-day period preceding admission to treatment. Results indicated that. over a 6-week test-retest interval, outpatient male alcohol abusers' self-reports of their daily drinking, alcohol-related incarcerations and their drinking problem history were highly reliable (r = +0.79 to +0.98). Limits on the generalizability of these finclings are discussed. 相似文献
920.
The treatment of an apparently authentic case of obsessional slowness is described. The relationship between behaviour change and emotional events is discussed. The findings replicate those of Rachman (1974). 相似文献