全文获取类型
收费全文 | 43223篇 |
免费 | 794篇 |
国内免费 | 11篇 |
专业分类
44028篇 |
出版年
2020年 | 228篇 |
2018年 | 3713篇 |
2017年 | 3077篇 |
2016年 | 2550篇 |
2015年 | 441篇 |
2014年 | 390篇 |
2013年 | 1860篇 |
2012年 | 1176篇 |
2011年 | 3002篇 |
2010年 | 2861篇 |
2009年 | 1829篇 |
2008年 | 2222篇 |
2007年 | 2682篇 |
2006年 | 560篇 |
2005年 | 689篇 |
2004年 | 641篇 |
2003年 | 539篇 |
2002年 | 561篇 |
2001年 | 773篇 |
2000年 | 803篇 |
1999年 | 586篇 |
1998年 | 291篇 |
1997年 | 249篇 |
1996年 | 229篇 |
1992年 | 461篇 |
1991年 | 432篇 |
1990年 | 465篇 |
1989年 | 431篇 |
1988年 | 421篇 |
1987年 | 416篇 |
1986年 | 420篇 |
1985年 | 443篇 |
1984年 | 346篇 |
1983年 | 320篇 |
1982年 | 257篇 |
1981年 | 233篇 |
1979年 | 397篇 |
1978年 | 296篇 |
1977年 | 270篇 |
1976年 | 236篇 |
1975年 | 351篇 |
1974年 | 380篇 |
1973年 | 364篇 |
1972年 | 333篇 |
1971年 | 291篇 |
1970年 | 262篇 |
1969年 | 324篇 |
1968年 | 361篇 |
1967年 | 326篇 |
1966年 | 326篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
C. L. G. Whitmore R. B. Lawson C. E. Kozora 《Attention, perception & psychophysics》1976,19(2):211-213
Stereoscopic depth and subjective contour clarity were manipulated by varying the type of monocular configuration as well as magnitude and direction of disparity. The clarity of the subjective contours was influenced significantly by both magnitude and direction of disparity and by the type of monocular configuration. Subjective contours were always less clear when the objective monocular contour was discontinuous regardless of disparity. Stereoscopic depth estimates varied directly with magnitude and direction of disparity; however, depth magnitude reports were truncated when the disparity was carried by discontinuously defined patterns. 相似文献
992.
Lloyd G Humphreys Pang-Chieh Lin Allen Fleishman 《Journal of research in personality》1976,10(1):42-58
Data consisting of 79 cognitive measures from Project TALENT for 100,000 white and black high school students have been analyzed for possible race by sex interactions. Control variables included geographical area, grade in high school, and socio-economic class. Race by sex interactions are largest when socioeconomic class is controlled and are highly related to the size of the main effect of sex as well. White boys and girls differ more than black boys and girls whether the overall sex difference favors males or females. Sex by grade and, to a lesser extent, sex by area interactions were also moderately large and consistent with the size of the main effect of sex. Since there are no consistent relationships with other main effects, and since the measures producing sex differences also tend to produce the interactions, it is concluded that sex differences and the interactions with sex share the same causes. Differences between these results and those of Jensen are also discussed. 相似文献
993.
G M Schwartz H S Hoffman C L Stitt R R Marsh 《Journal of experimental psychology. Animal behavior processes》1976,2(1):28-37
Male hooded and albino rats were exposed to a light flash followed at various temporal intervals by a startle-eliciting 117 db. (re 20 muN/m2) burst of white noise. The visual stimulus engendered startle response inhibition (maximally when the lead time was 64-250 msec) as well as startle response latency reduction (maximally when the lead time was 2-8 msec). The temporal functions for the effects of visual stimuli paralleled those previously reported for startle modification by acoustic events. Further study revealed that, given optimal lead times, inhibition is produced reliably by weaker visual stimuli (3 X 10-6 cd-sec/cm2) than latency reduction (3 X 10-4 cd-sec/cm2). This differential sensitivity to visual stimuli is also analogous to previously reported findings for events in the acoustic environment. It reveals that the neural mechanisms that mediate latency reduction and inhibition can be engaged by either acoustic or visual stimulation. 相似文献
994.
An analysis of the meanings attached to 'careers education' in Britain and to 'career education' in the USA reveals a number of important differences, each of which identifies questionable assumptions in the careers education model emerging in Britain. Attention is also addressed to three major problems which have received inadequate attention in both countries: the socio-political aims of career(s) education, the extent to which it should be concerned with paid employment, and the relationship between the content of careers education curricula and the institutional structures within which these curricula are based. 相似文献
995.
996.
997.
Following a left CVA, a skilled professional typist sustained a disturbance of typing disproportionate to her handwriting disturbance. Typing errors were predominantly of the sequencing type, with spatial errors much less frequent, suggesting that the impairment was based on a relatively early (premotor) stage of processing. Depriving the subject of visual feedback during handwriting greatly increased her error rate. Similarly, interfering with auditory feedback during speech substantially reduced her self-correction of speech errors. These findings suggested that impaired ability to utilize somesthetic information--probably caused by the subject's parietal lobe lesion--may have been the basis of the typing disorder. 相似文献
998.
999.
This study examined the relationships between metamemory and strategic behavior in impulsive and reflective children. One hundred thirty children from the fourth, fifth, and sixth grades participated. Seventy-seven of these children had been tested 3 years earlier on metamemory and cognitive tempo tasks. At pretraining, children were assessed on metamemory, cognitive tempo, summarization skills, and teacher ratings of impulsive behavior in the classroom. Next, children in three experimental groups received prose summarization instructions, summarization instructions in conjunction with metacognitive training about the importance of a reflective approach to learning, or no instructions. Following training, children were again measured on tempo, summarization skills, and teacher ratings of impulsivity. Analyses of strategy maintenance data indicated superior performance for children who had received both summarization and metacognitive training. Causal modeling analyses showed that early metamemory was an antecedent of later strategy acquisition. The dual role of metacognition as a precursor of later strategy acquisition and controller of lower level strategies was highlighted. 相似文献
1000.