全文获取类型
收费全文 | 48397篇 |
免费 | 1689篇 |
国内免费 | 22篇 |
出版年
2019年 | 470篇 |
2018年 | 633篇 |
2017年 | 678篇 |
2016年 | 750篇 |
2015年 | 550篇 |
2014年 | 661篇 |
2013年 | 3507篇 |
2012年 | 1195篇 |
2011年 | 1250篇 |
2010年 | 803篇 |
2009年 | 793篇 |
2008年 | 1188篇 |
2007年 | 1070篇 |
2006年 | 984篇 |
2005年 | 915篇 |
2004年 | 867篇 |
2003年 | 886篇 |
2002年 | 925篇 |
2001年 | 1267篇 |
2000年 | 1244篇 |
1999年 | 928篇 |
1998年 | 481篇 |
1997年 | 487篇 |
1992年 | 906篇 |
1991年 | 849篇 |
1990年 | 866篇 |
1989年 | 839篇 |
1988年 | 795篇 |
1987年 | 782篇 |
1986年 | 841篇 |
1985年 | 863篇 |
1984年 | 740篇 |
1983年 | 680篇 |
1982年 | 499篇 |
1981年 | 561篇 |
1979年 | 802篇 |
1978年 | 619篇 |
1977年 | 546篇 |
1976年 | 544篇 |
1975年 | 706篇 |
1974年 | 839篇 |
1973年 | 888篇 |
1972年 | 707篇 |
1971年 | 720篇 |
1970年 | 671篇 |
1969年 | 710篇 |
1968年 | 881篇 |
1967年 | 814篇 |
1966年 | 816篇 |
1958年 | 469篇 |
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
881.
882.
A computer system, based on the Radio Shack Color Computer, for running experiments in cognitive psychology is described. The system was designed according to the following principles: first, all of the equipment should consist of inexpensive, off-the-shelf components; second, the language used to implement experiments should have real-time commands embedded within the character strings to be displayed, and these real-time commands should be interpreted at run time; third, the system should serve multiple subjects, yet one host should be able to run display terminals for several subjects on independent experiments; and fourth, the system should be able to interface to other display devices and other response-recording devices. Two examples of other devices are discussed: an oscilloscope for rapid visual display and an Apple Macintosh for display of pictures. 相似文献
883.
884.
The ability of infants to perceive three-dimensional structure from transformations of linear perspective was investigated in two studies. Infants were habituated to the pattern of linear perspective transformations corresponding to a particular three-dimensional object, and their relative preference for that object as compared with a different three-dimensional object was assessed both before and after habituation. The habituation displays showed the distorting shadow cast by a rotating object and therefore provided only transformations of linear perspective as information specifying three-dimensional form. The pre- and posttest displays involved the actual three-dimensional objects and provided binocular, shading, and texture information specifying three-dimensional form, but did not provide informative transformations of linear perspective. In Study 1, 6-month-olds showed changes in preference from pre- to posttest that were related to the identity of the object whose shadow they had seen during habituation; 4-month-olds, however, did not show preference changes related to the habituation object. In Study 2, rhythm information that may have served as a basis for responding in Study 1 was eliminated from the test displays. Six-month-olds again showed changes in preference that were dependent on their habituation experience. It is concluded that, by 6 months of age, infants are able to perceive object structure from the isolated cue of transformations of linear perspective. The findings are discussed with reference to infants’ three-dimensional form perception based on other cues and also with reference to the emergence of certain spatially related moter activities. 相似文献
885.
Stanley Coren Clare Porac Leonard H. Theodor 《Attention, perception & psychophysics》1986,39(5):327-333
Two experiments showed the influence of perceptual set on the perception of subjective contours. In the first, the perceived shape of a subjective-contour figure (a minimal version of the Ehrenstein configuration) was varied by altering the observer’s viewing set. The second experiment showed that apparent depth emerged in subjective-contour figures when observers were set to perceive the illusory contours. 相似文献
886.
A. H. C. van der Heijden R. Schreuder L. Maris M. Neerincx 《Attention, perception & psychophysics》1984,36(6):577-585
This study investigates the separate activation versus coactivation issue for redundant targets in a simple letter-detection paradigm with latency as the dependent variable. The results of a one-response visual-search task are reported. Since, on single-target trials, only the target was presented and no accompanying noise element, no “distraction decrement” caused by irrelevant noise elements (Grice et al., 1984) was to be expected. The data obtained showed a clear redundantsignal effect. Subsequent detailed analysis of the latency data using Miller’s (1982) procedure indicated that the results were consistent with a separate activation model and failed to provide convincing evidence in favor of coactivation models. A further analysis of the data indicated that, in the present study, the separate channels were negatively correlated for a range of fast RTs and positively correlated for intermediate and larger RTs. No evidence in favor of Grice et al.’s (1984) distraction-decrement hypothesis was found. The conclusions of this study are that (1) a separate activation model summarizes the essential features of information processing in this simple visual search task, and (2) no convincing evidence in favor of coactivation in visual search tasks has been reported in the literature up to now. 相似文献
887.
Six tasks administered on a MINC-11 minicomputer were used in studying the effects of long, continuous work periods and fatigue on physical and cognitive task performance. Submaximal physiological workload measurement was done during one of these tasks for a subject walking on a treadmill. The MINC-11 system is described, as are the six tasks programs. Four of these tasks measured various types of reaction times, another involved complex information processing, and one appraised moods, physical symptoms, fatigue, and the physiological status of subjects. 相似文献
888.
Patricia H. Werhane 《Theoretical medicine and bioethics》1984,5(3):359-363
The recent Supreme Court decision upholding Roe v. Wade and in particular, the dissent by Justice Sandra Day O'Connor, sheds new light on the issue of abortion. Let us consider any stage of a pregnancy when abortion is medically safe for the mother. If at that stage it is also medically viable to save the fetus, is an abortion performed at that stage of pregnancy morally justifiable? For example, if it is, or becomes, medically safe to perform abortions after first trimester of pregnancy and at the same time saving a fetus is, or becomes, medically viable or not unusual during some stage of the second trimester, can abortions during and after that stage of pregnancy be justified? With a number of qualifications I shall argue the thesis that as a general rule, but not an absolute rule, abortion in these instances is not usually justifiable. For if it is, then one will also have to grant the moral justification for a number of other highly questionable medical practices. This thesis is not to be identified with the stronger claim that abortions of viable fetuses can never be performed. There are surely exceptions such as when the life or health of the mother is in danger. But, I shall argue, the justification for making such exceptions is on different grounds than is sometimes claimed because one must weigh the health of the mother against the life of another human being. 相似文献
889.
An analysis of some sensitizing agents in the pathogenesis of stress-induced gastric erosive disease
B. H. Natelson M. Ferrara-Ryan D. Creighton J. Yavorsky G. Curtis W. N. Tapp 《Integrative psychological & behavioral science》1984,19(4):195-199
Prior surgical implantation of a venous catheter sensitized rats to coldimmobilization stress. Three of six catheterized females succumbed during the stress. The remaining rats fell into two groups in terms of their core temperature at the end of the stress period: Male uncatheterized rats had higher temperatures than rats in the other three groups. No relation was found between catheter patency and magnitude of hypothermia. Degree of gastric disease paralleled the core temperature findings in that the male uncatheterized rats had significantly fewer gastric erosions than the rats in the other three groups. Additionally, a robust effect of gender was found with uncatheterized females showing more hypothermia and more gastric disease than uncatheterized males. A subsequent experiment was conducted to evaluate whether anesthesia or wearing the protective spring was responsible in part for the sensitization seen. Here, the gender difference was less although females consistently averaged lower core temperatures after stress than did males. Despite similar core temperatures after stress, females that were prepared with the protective spring apparatus developed more gastric disease than female controls or similarly treated males. Thus, the additional sensitization exhibited by females in the first experiment may relate to the fact that both catheterization and the taping procedure were sensitizers while only catheterization was a sensitizer for males. 相似文献
890.
S. Stefan Soltysik Thomas Nicholas W. Jeffrey Wilson 《Integrative psychological & behavioral science》1984,19(4):169-181
Respiratory rate, respiration amplitude, and vocal responses were recorded in cats of different ages during classic conditioning. Vocal responses to the conditional stimulus (CS) appeared first in 8-week-old kittens, and became prominent at older ages. An increase in respiration rate occurred after the onset of the CS in cats of all ages. Similarly, the decrease of respiration amplitude was observed at all ages, but only in 8-week-old and older subjects did this response resemble an adult pattern. In 4-week-old kittens the response was characterized by an early and brief peak, suggesting an alpha conditional response (CR). Clear and significant discrimination between a warning and a safety signal was present in both respiratory and vocal responses after the age of 8 weeks. 相似文献