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   64303篇
  免费   2459篇
  国内免费   31篇
  66793篇
  2020年   682篇
  2019年   889篇
  2018年   1201篇
  2017年   1317篇
  2016年   1278篇
  2015年   921篇
  2014年   1089篇
  2013年   5051篇
  2012年   1963篇
  2011年   2071篇
  2010年   1338篇
  2009年   1313篇
  2008年   1867篇
  2007年   1836篇
  2006年   1656篇
  2005年   1446篇
  2004年   1349篇
  2003年   1347篇
  2002年   1297篇
  2001年   2108篇
  2000年   2040篇
  1999年   1552篇
  1998年   696篇
  1997年   633篇
  1996年   605篇
  1994年   606篇
  1992年   1309篇
  1991年   1206篇
  1990年   1223篇
  1989年   1107篇
  1988年   1108篇
  1987年   1069篇
  1986年   1061篇
  1985年   1068篇
  1984年   905篇
  1983年   791篇
  1982年   603篇
  1979年   959篇
  1978年   702篇
  1977年   631篇
  1975年   797篇
  1974年   851篇
  1973年   938篇
  1972年   741篇
  1971年   669篇
  1970年   619篇
  1969年   690篇
  1968年   792篇
  1967年   719篇
  1966年   701篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
871.
Alternate monocular and binocular exposure to complementary stimulation can yield opposite but coexisting aftereffects that are contingent on whether the test display is viewed with one eye or two eyes. The motion aftereffect was studied by adapting each eye separately to a contracting spiral and both eyes together to an expanding spiral. The stationary test spiral subsequently appeared to be expanding when viewed monocularly, but to be contracting when it was seen with both eyes open. With respect to the McCollough effect, after monocular exposure to red-vertical and green-horizontal gratings and binocular exposure to red-horizontal and green-vertical gratings, the appearance of the color of the test gratings when viewed with one eye was different from that when viewed with both eyes. Opposite, coexisting aftereffects induced by complementary stimulation can be interpreted as evidence that there are unique binocular aspects to visual function.  相似文献   
872.
A McCollough effect was induced in subjects by having them view typical adapting stimuli binocularly for 5 min. In the control condition, the strength of the McCollough effect was measured 20 min after the end of the adaptation. The strength was measured during monocular and binocular viewing of a test pattern via a color cancellation technique. Monocular strengths for the two eyes of a given subject were equal to each other and slightly weaker than the binocular strength. In the test condition, 15 min of the 20 min between adaptation and testing were spent monocularly viewing black and white gratings of the same orientation and spatial frequency as the adapting gratings. The strength of the effect as measured ipsilaterally was markedly decreased from that in the control condition. The strength of the effect as measured with the contralateral eye showed only a small decrease from that of the control condition. This finding is relevant to various models of the McCollough effect and related color aftereffects, especially those that posit a “learning” type of mechanism between achromatic spatial channels (which exhibit clear interocular transfer of various achromatic effects) and monocular color channels.  相似文献   
873.
A survey of academic psychologists was taken to determine present use of computers in instruction, willingness to use good education software, and kinds of potential uses of computers in psychology courses. A majority of the respondents reported using computers in instruction. Respondents indicated substantial willingness to adopt computer-based courseware. Respondents believed that a variety of uses, including classroom demonstrations and student experiments, would facilitate student learning. The results of the survey are compared with the instructional modules the task force is developing.  相似文献   
874.
There exist surprisingly few normative lists of word meanings even though homographs—words having single spellings but two or more distinct meanings—are useful in studying memory and language. The meaning norms that are available all have one or more weaknesses, including: (1) the collection of free associates rather than meanings as responses to the stimulus words; (2) the collection of single rather than multiple responses to the stimulus words; (3) the inclusion of only the two most frequently occurring meaning categories, rather than all meaning categories, for the stimulus words; (4) omission of the responses typical of each meaning category; (5) inadequate randomization of the presentation order of the stimulus words; and (6) unpaced presentation of the stimulus words. We have compiled meaning norms for 90 common English words of low, medium, and high concreteness using a methodology designed to correct these weaknesses. Analysis showed that words of medium concreteness have significantly more first-response meanings than do words of either low or high concreteness, lending support to the view that concreteness is a categorical, rather than a continuous, semantic attribute.  相似文献   
875.
Simulations of space use by animals were run to determine the relationship among home range area estimates, variability, and sample size (number of locations). As sample size increased, home range size increased asymptotically, whereas variability decreased among mean home range area estimates generated by multiple simulations for the same sample size. Our results suggest that field workers should ascertain between 100 and 200 locations in order to estimate reliably home range area. In some cases, this suggested guideline is higher than values found in the few published studies in which the relationship between home range area and number of locations is addressed. Sampling differences for small species occupying relatively small home ranges indicate that fewer locations may be sufficient to allow for a reliable estimate of home range. Intraspecific variability in social status (group member, loner, resident, transient), age, sex, reproductive condition, and food resources also have to be considered, as do season, habitat, and differences in sampling and analytical methods. Comparative data still are needed.  相似文献   
876.
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   
877.
When a relatively weak signal, such as a mild tone, precedes an intense reflex-eliciting stimulus by an appropriate interval (about 100 msec), the amplitude of the elicited reaction is often reduced. It was found that in student volunteers a brief gap in a steady pure tone that occurred 150 msec prior to a mild tap to the glabella (the flat region between the eyebrows) could inhibit the eyeblink elicited by the tap. It was also found that a shift in tonal frequency across a gap in a tone was more inhibitory than a gap with no frequency shift, but it was no more inhibitory than the onset of the short second tone alone. The final study determined the minimum amount of frequency shift required to produce an additional inhibitory effect above that of a gap alone. The findings are discussed in terms of various aspects of sensory processing.  相似文献   
878.
An experiment which employed each of 18 subjects in four days of testing was used to examine acute secobarbital dose treatment effects on choice reaction time in a Cooper and Shepard (1973) character recognition task. Manipulations of visual stimulus degradation, character difficulty, 180 degree rotation, and mirror-image reversal were included in order to evaluate the hypothesis that the drug affects performance by disrupting early stimulus input processing. The results indicate significant increases in the effect of secobarbital on reaction time and errors under conditions of visual stimulus degradation. The effects of the drug, however, were not changed by 180 degree rotation of the target character or by the other task variables. The results were interpreted to indicate that secobarbital impairs performance primarily by placing selective stress on hypothetical early encoding activities and that later processing operations (associated with use of an internal representation of the target character) are not affected by the drug. Strengths and weaknesses of the two-stage model of visual stimulus processing are discussed and implications of the model for future drug research are indicated.  相似文献   
879.
Three measures of chronic self-esteem, plus four measures developed to assess situational components of self-esteem (task-specific self-esteem and social self-esteem), were administered to 238 undergraduates at a large, urban university and a community college in the southeastern United States. Evidence for a composite construct of self-esteem was found. Results also indicate task-specific self-esteem correlates as high as .42 (p < .01) with chronic self-esteem and as high as .76 (p < .01) with social self-esteem. Task-specific self-esteem was found to be a better predictor of grade point average than chronic or social self-esteem. Suggestions are made for further research on the situational components of self-esteem to extend current findings.  相似文献   
880.
It is by the application of the principle of neutrality, born of his respect for the essential otherness of the patient, that the analyst focuses the dyadic analytic work in the service of the patient's growing self-analytic capacity. Thus, the general principle of neutrality is distinguished from the technical tactic of abstinence, the latter being a specific function utilized to facilitate and foster analytic regression. Neutrality can be defined as it applies to the major subfunctions of the analyst's work ego. Perception of the patient's intrapsychic processes (both empathically and cognitively) requires a neutrality of appearance on the analyst's part in order to minimize the distortion of the unfolding transference neurosis. Integration and understanding of the patient's communications require mastery and neutralization of the analyst's own internal processes in order to minimize countertransferential distortions. Appropriate interpretive intervention requires neutrality of action, i.e., mastery of impulses related to power, neutralizing them into the service of the analytic work; tact is defined as a specific psychoanalytic function in this regard. Collaborative ignorance is examined as a specific instance of false neutrality. In this an analytic guise serves to mask a countertransferential conflict. Neutrality serves as an overriding technical principle, not an imperative for perfectionism . Factors intrinsic to the analytic process also influence the application of this principle.  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