首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   23343篇
  免费   913篇
  国内免费   11篇
  24267篇
  2020年   212篇
  2019年   270篇
  2018年   390篇
  2017年   431篇
  2016年   442篇
  2015年   347篇
  2014年   371篇
  2013年   1963篇
  2012年   665篇
  2011年   692篇
  2010年   415篇
  2009年   393篇
  2008年   534篇
  2007年   597篇
  2006年   513篇
  2005年   480篇
  2004年   446篇
  2003年   448篇
  2002年   482篇
  2001年   767篇
  2000年   725篇
  1999年   556篇
  1998年   233篇
  1996年   239篇
  1992年   473篇
  1991年   470篇
  1990年   439篇
  1989年   412篇
  1988年   432篇
  1987年   392篇
  1986年   413篇
  1985年   410篇
  1984年   331篇
  1983年   300篇
  1982年   237篇
  1981年   227篇
  1979年   373篇
  1978年   277篇
  1977年   236篇
  1976年   218篇
  1975年   298篇
  1974年   383篇
  1973年   384篇
  1972年   296篇
  1971年   298篇
  1970年   296篇
  1969年   260篇
  1968年   357篇
  1967年   317篇
  1966年   293篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
911.
Most dimensional analyses of traditional Rorschach scoring categories have either failed to control for differences in total R or have done so by introducing a nonstandard mode of administration. Consequently, the results of such studies may be either distorted or of questionable relevance to more typical situations. The present analyses, which compared both group and individual forms of the Rorschach administered to large samples (over 500 each) of male medical students, controlled for differences in total R by using residualized scores from which the linear effects of R had been partialled. The factor-analytic results are expressed in terms of seven easily interpretable factors (including total R), five of which are similar across forms, and simple formulas for deriving norm-referenced factor scores from the data of individual test administrations are provided.  相似文献   
912.
913.
Three experiments demonstrated that prior training with one stimulus (CS1) would block acquisition of the rabbit's nictitating membrane response (NMR) to another stimulus (CS2) which was more contiguous to the US during serial compound training (CS1-CS2-US). Specifically, the CS1-US interval was 800 msec, which produces only a modest rate of CR acquisition, while the CS2-US interval was 400 msec, which is an optimal value for the NMR preparation. Experiment 1 demonstrated blocking when CS1 overlapped CS2, and Experiment 3 demonstrated blocking when CS1 and CS2 were presented in a strictly sequential fashion. Experiment 2 showed that the magnitude of blocking in the serial compound was comparable to that obtained in a simultaneous compound in which both the CS1-US and CS2-US intervals were 800 msec, thus making CS2 less contiguous with the US than in the serial compound. Moreover, the level of responding to CS2 in all serial compound groups (blocking and control) was lower than in the simultaneous compound groups. The present findings provide further evidence that the associative consequences of CS-US contiguity can be highly attenuated by processes of attention or competition for associative strength.  相似文献   
914.
Two experiments investigated whether steady-state interactions in multiple schedules depend exclusively on the following schedule of reinforcement. Experiment 1 used a four-component multiple schedule in which two components were associated with the same constant schedule of reinforcement, and where rate of reinforcement was varied in the component that followed one of these. Contrast effects were reliable only in the component that preceded the point of reinforcement variation, although some contrast did occur otherwise. In those instances where contrast other than the following-schedule effect did occur, it was accounted for by the effect of the preceding schedule, an effect for which there were consistent individual differences among subjects, and which varied with component duration. Experiment 2 used a three-component schedule, in which reinforcement rate was varied in the middle component. The results were consistent with Experiment 1, as the following-schedule effect was the only consistent effect that occurred, although an effect of the preceding schedule did occur for some subjects under some conditions, and was especially evident early in training. The conclusion from both experiments is that there is no general effect of relative rate of reinforcement apart from the sum of the effects of the preceding and following schedules, and that the following-schedule effect is the fundamental cause of steady-state interactions.  相似文献   
915.
Pigeons were trained in delayed matching-to-sample with two postsample stimuli. A postsample R-cue signaled that a matching choice phase would follow. A postsample F-cue signaled that a matching choice phase would not follow. Previous research found reduced matching accuracy on F-cued probe trials when comparison stimuli were presented in the choice phase. The present four experiments systematically varied the events following an F-cue to determine the conditions under which the F-cue reduces delayed-matching accuracy. When F-cues and R-cues controlled different behavior, matching on probe trials was poor. When both cues controlled the same behavior, matching on probe trials was good. This result is best explained by the theory that comparison stimuli retrieve the sample representation, but only in the behavioral context established by the R-cue. The present research supports the view that response-produced stimuli serve a contextual role in animal short-term memory.  相似文献   
916.
The testing of Convulsofin carried out in 220 patients at 14 clinics over a period of six months confirms the international experience gained with valproic acid and sodium valproinate. The main field of application of Convulsofin according to the experience gained will again be the treatment of fits in generalised primary epilepsy for which it permits to carry out a monotherapy to a remarkable extent. The favourable effect of the preparation in photosensitivity could be confirmed. Also in generalised secondary epilepsy and in fits of partial epilepsy. Convulsofin is partly effective, so that it can recommended as a co-medication in the treatment of therapy-resistant forms of these epilepsies which are difficult to treat. Decrease in thrombocytes, transient increase in serum transaminases, gastrointestinal disorders, loss of hair and undesired increases in body-weight were the more frequently occurring side-effects.  相似文献   
917.
Directional judgments are typically slower when relative location is described by the words “east” and “west” or “right” and “left” than when described by the words “north” and “south” or “up” and “down.” A series of experiments are reported that disentangle verbal from perceptual encoding explanations for right-left difficulty. Overall, our results support a verbal encoding explanation for right-left confusion in the adult. Experiments 1-3 demonstrate that in a response-differentiation task, it is response to the labels “north,” “east,” “south,” and “west” that is responsible for right-left confusion. In addition, Experiments 4-6 demonstrate that right-left difficulty in a mirror image discrimination task is contingent on the use of directional labels. (The data also suggest that it may be more difficult to deal with “up,” “down,” “left,” and “right” than with “north,” “south,” “east,” and “west”) The data are interpreted as inconsistent with a bilateral symmetry explanation for right-left confusion.  相似文献   
918.
The three experiments reported in this study were each conducted in two phases. The first phase of Experiment 1 involved a same-different comparison task requiring “same” responses for both mixed-case (e.g., MAIN main) and pure-case (e.g., near near) pairs. This was followed by Phase 2, a surprise recognition test in which a graphemic effect on word retention was indicated by the superior recognition accuracy obtained for pure-case compared with mixed-case pairs. The first phases of Experiments 2 and 3 involved pronounceability and imageability judgment tasks, respectively. Graphemic retention was assessed by contrasting recognition accuracy for letter strings presented, during Phase 2, in their original Phase 1 case, with letter strings presented, during Phase 2, in. a graphemically dissimilar new case. The experiments provided evidence that there was minimal retention of the graphemic representations from which the phonemic representations of words are generated and, further, that the locus of this effect is probably postlexical. Nonwords were recognized more accurately than words in all three experiments. The latter result was attributed to differences between nonwords and words in both graphemic retention and semantic distinctiveness.  相似文献   
919.
920.
To assess the development of dichotic ear asymmetries and handedness, 208 male school children were evaluated in kindergarten and at Grades 2 and 5 (ages 66, 92, and 130 months of age, respectively) with a dichotic listening task and a hand preference test. The Wide Range Achievement Test (WRAT) also was administered at each of the three grade levels. There was significant variability in handedness scores over time only for those subjects whose scores at initial testing, that is, in kindergarten, identified them as non-right-handers. Both right and left handers had a significant increase in dichotic listening scores over time; however, only right handers had a significant right ear advantage at each evaluation. Regression analyses showed that combined hand preference scores and ear recall scores at each probe when combined accounted for almost 44% of the variance in WRAT achievement scores at Grade 5. Ear asymmetry scores, however, were not predictive of school achievement.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号