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   63815篇
  免费   2571篇
  国内免费   20篇
  66406篇
  2020年   611篇
  2019年   804篇
  2018年   1068篇
  2017年   1110篇
  2016年   1175篇
  2015年   871篇
  2014年   1014篇
  2013年   4754篇
  2012年   1885篇
  2011年   2068篇
  2010年   1272篇
  2009年   1265篇
  2008年   1781篇
  2007年   1806篇
  2006年   1651篇
  2005年   1454篇
  2004年   1350篇
  2003年   1264篇
  2002年   1388篇
  2001年   2101篇
  2000年   2079篇
  1999年   1564篇
  1998年   722篇
  1997年   641篇
  1996年   647篇
  1993年   585篇
  1992年   1315篇
  1991年   1222篇
  1990年   1199篇
  1989年   1092篇
  1988年   1078篇
  1987年   1033篇
  1986年   1115篇
  1985年   1124篇
  1984年   945篇
  1983年   853篇
  1982年   600篇
  1981年   604篇
  1979年   1014篇
  1978年   713篇
  1975年   814篇
  1974年   895篇
  1973年   976篇
  1972年   820篇
  1971年   780篇
  1970年   699篇
  1969年   724篇
  1968年   906篇
  1967年   843篇
  1966年   686篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
181.
Connectionism and cognitive architecture: a critical analysis   总被引:54,自引:0,他引:54  
J A Fodor  Z W Pylyshyn 《Cognition》1988,28(1-2):3-71
  相似文献   
182.
A precursor of language acquisition in young infants   总被引:6,自引:0,他引:6  
  相似文献   
183.
184.
185.
186.
Love and Lust Revisited: intentionality, homosexuality and moral education   总被引:1,自引:0,他引:1  
ABSTRACT In his book Sexual Desire , Roger Scruton wrongly maintains that human sexual experience is essentially intentional. His thesis depends on his highly revisionary definitions of 'sexual arousal' and 'sexual desire', the artificial nature of which I expose and criticise.
He admits that homosexual desire is capable of the same kind of intentionality as heterosexual desire, and is therefore not intrinsically obscene or perverted, but he advances reasons why homosexuality is morally different from heterosexuality and is therefore an object of disapproval. His arguments presuppose 'an impassable moral divide' between the sexes and are, on his own admission, not very cogent.
Since he allows that homosexual desire is a natural and spontaneous phenomenon and also proposes that moral education should guide us towards a state in which our sexuality is entirely integrated within a life of personal affection and responsibility, consistency requires that he adopt a sexual ideology which does not discriminate against homosexuality. For homosexuals are unlikely to achieve the 'sexual integrity' which Scruton advocates (and which I endorse) if they are constantly encouraged to disparage their own sexual nature and if social institutions make no positive provision for them.  相似文献   
187.
J R Lackner  P DiZio 《Perception》1988,17(1):71-80
When a limb is used for locomotion, patterns of afferent and efferent activity related to its own motion are present as well as visual, vestibular, and other proprioceptive information about motion of the whole body. A study is reported in which it was asked whether visual stimulation present during whole-body motion can influence the perception of the leg movements propelling the body. Subjects were tested in conditions in which the stepping movements they made were identical but the amount of body displacement relative to inertial space and to the visual surround varied. These test conditions were created by getting the subjects to walk on a rotatable platform centered inside a large, independently rotatable, optokinetic drum. In each test condition, subjects, without looking at their legs, compared, against a standard condition in which the floor and drum were both stationary, their speed of body motion, their stride length and stepping rate, the direction of their steps, and the perceived force they exerted during stepping. When visual surround motion was incompatible with the motion normally associated with the stepping movements being made, changes in apparent body motion and in the awareness of the frequency, extent, and direction of the voluntary stepping movements resulted.  相似文献   
188.
Orientation discrimination and cortical function in the human newborn   总被引:1,自引:0,他引:1  
A Slater  V Morison  M Somers 《Perception》1988,17(5):597-602
There is some controversy concerning whether or not the visual abilities of the newborn are mediated entirely through subcortical pathways or whether the visual cortex is functioning at birth. A critical test of cortical functioning is discrimination of orientation: orientation-selective neurons are found in the visual cortex but not in subcortical parts of the visual system. An experiment is described in which newborn infants were habituated to a square-wave grating oriented 45 degrees from vertical. After habituation, significant preferences for the novel, mirror-image, grating were found, a result which argues for some degree of visual cortical functioning at birth.  相似文献   
189.
Iconic memory, which was initially regarded as a unitary phenomenon, has since been subdivided into several components. In the present work we examined the joint effects of two such components (visible persistence and the visual analog representation) on performance in a partial report task. The display consisted of 15 alphabetic characters arranged around the perimeter of an imaginary circle on the face of an oscilloscope. The observer named the character singled out by a bar-probe. Two factors were varied: exposure duration of the array (10, 50, 100, 150, 200, 300, 400 or 500 ms) and duration of blank period (interstimulus interval, ISI) between the termination of the array and the onset of the probe (0, 50, 100, 150, or 200 ms). Performance was progressively impaired as both exposure duration and ISI were increased. The results were explained in terms of a probabilistic combinatorial model in which the timecourses of visible persistence and of the visual analog representation are regarded as time-locked to the onset and to the end of stimulation, respectively. The impairing effect of exposure duration was attributed to the relatively high spatial demands of the task that could be met optimally by information in visible persistence (which declines as a function of exposure duration), but less adequately by information in the visual analog representation. A second experiment, employing a task with lesser spatial demands, confirmed this interpretation.  相似文献   
190.
The possibility that rats can navigate in the Morris water maze by reducing the difference between the memorized platform scene and the current sensory input was tested in nine blind rats. A computerized videosystem monitored the rats' movements in the pool and converted the rat-target distance into tones the frequency of which increased in 64 equal steps from 120 Hz at 128 cm to 7680 Hz at 0 cm. During 15 days of training to find a fixed platform position from different starting points (12 trials per day) average escape latencies decreased from 39.0 to 25.4 s. The performance significantly deteriorated when the acoustic distance signalization was omitted and/or when the target position was changed form trial to trial. It is concluded that blind rats solved the task by simultaneously employing search strategy based on position responses, mapping using acoustic background beacons, and distance reduction navigation. It is argued that the various strategies are additive and that their relative significance depends of the conditions of the experiment.  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