全文获取类型
收费全文 | 33899篇 |
免费 | 1433篇 |
国内免费 | 16篇 |
出版年
2020年 | 386篇 |
2019年 | 420篇 |
2018年 | 646篇 |
2017年 | 621篇 |
2016年 | 652篇 |
2015年 | 459篇 |
2014年 | 622篇 |
2013年 | 2963篇 |
2012年 | 1058篇 |
2011年 | 1150篇 |
2010年 | 661篇 |
2009年 | 754篇 |
2008年 | 1058篇 |
2007年 | 1005篇 |
2006年 | 954篇 |
2005年 | 898篇 |
2004年 | 875篇 |
2003年 | 854篇 |
2002年 | 837篇 |
2001年 | 1013篇 |
2000年 | 971篇 |
1999年 | 777篇 |
1998年 | 441篇 |
1997年 | 408篇 |
1996年 | 345篇 |
1995年 | 360篇 |
1994年 | 319篇 |
1993年 | 361篇 |
1992年 | 644篇 |
1991年 | 559篇 |
1990年 | 623篇 |
1989年 | 524篇 |
1988年 | 499篇 |
1987年 | 493篇 |
1986年 | 501篇 |
1985年 | 579篇 |
1984年 | 509篇 |
1983年 | 466篇 |
1982年 | 399篇 |
1981年 | 356篇 |
1979年 | 448篇 |
1978年 | 423篇 |
1977年 | 351篇 |
1976年 | 346篇 |
1975年 | 432篇 |
1974年 | 493篇 |
1973年 | 450篇 |
1972年 | 347篇 |
1968年 | 358篇 |
1966年 | 329篇 |
排序方式: 共有10000条查询结果,搜索用时 218 毫秒
861.
862.
863.
In this paper, we describe software that turns a Macintosh computer into an off-the-shelf tool for experiments on visual search. Our design goals included portability (between members of the Macintosh computer family and between various research settings), user-friendliness (equivalent to Macintosh programming standards), flexibility (to allow replication and extension of important experiments on visual search), and adaptability (very short design-to-data and data-to-analysis turnaround times). We describe how the software meets these goals in three major phases of an experiment: stimulus construction, experimental control, and statistical analysis. We then list several landmark studies of visual search that can be easily designed and extended with the software. Finally, we outline plans for expanding the experimental variations that will be supported in future versions of the software. 相似文献
864.
An automated system for measuring intracranial self-stimulation behavior is described. The system consists of two Commodore 6502 microcomputers interfaced with a constant-current generator and a standard operant chamber. The system hardware allows sine- and square-wave stimulation. Stimulus intensity can be varied in 256 steps between 0 and 100, 0 and 500, or 0 and 1,000 /µA. The system programs, which are written in machine language, allow the control of various schedules of reinforcement, the counting of operant responses and reinforcements, the measurement of interresponse intervals, and the storage of the data on disk. The software is designed for the determination of the threshold of reinforcement, on the basis of the titration of postreinforcement pauses caused by changeover in schedule control between concurrent continuous reinforcement and fixed ratio schedules. 相似文献
865.
John B. Pittenger 《Attention, perception & psychophysics》1990,48(2):124-130
Growth systematically changes the body proportions of both humans and animals so that the ratio of head height to body height decreases with age. Prior studies have demonstrated that body proportions provide effective information for age perception. To test the proposal that illustrators incorporate this information into their drawings, measurements were made of the head and body heights of 100 pairs of animals appearing in children’s picture books. In 93 pairs, the animal intended to be perceived as older had a smaller head-to-body ratio than did the younger animal. Ratings collected for 25 of these pairs showed that both perceived age and cuteness are significantly correlated with body proportions. The magnitudes of the correlations were only modest, suggesting that other aspects of the drawings influenced perceived age and cuteness. In addition, observers reported that body proportions are only one of a variety of factors influencing age and cuteness perception. As has been found in other studies, perceived age and cuteness were negatively correlated. 相似文献
866.
OPTIMISM AND FUNDAMENTALISM 总被引:2,自引:0,他引:2
867.
Young Children's Understanding of Thinking and Consciousness 总被引:2,自引:0,他引:2
John H. Flavell 《Current directions in psychological science》1993,2(2):40-40
868.
869.
Depression in some patients with spinal cord injuries may be clinically significant and, when present, should be treated to
decrease morbidity including decreased physical functioning. Depression associated with spinal cord injury (SCI) may be misevaluated,
due to (1) nonspecific multifactorial production of depression symptoms and (2) SCI-specific decrease in somatic sensory central
nervous system input. The Somatic Suppression Hypothesis suggests that SCI patients have difficulty experiencing any intense
emotion because of suppression of physiological arousal. In addition, cognitive processes that may reduce depression in SCI
patients include: (1) attribution of somatic symptoms of depression to medical (biological) causes, (2) realistic, positive
expectations for physical improvement, and (3) the perception that the disability of the SCI is only minimally related to
the patient’s self-care after complete evaluation. Health personnel should accept lack of depression in SCI, and should encourage
positive realistic expectations of recovery. 相似文献
870.
Donna Y. Ford J. John Harris James M. Schuerger 《Journal of counseling and development : JCD》1993,71(4):409-417
A review of the literature suggests that a paucity of information exists regarding how culture-specific issues such as being both Black and gifted influence the psychological needs and personality development of gifted Black students. Stellar attempts, however, are currently underway to develop theories and perspectives of racial identity development among Black students. These theories and perspectives are discussed in an attempt to understand and address the psychological and social needs of gifted Black students. 相似文献