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   31084篇
  免费   1437篇
  国内免费   21篇
  2020年   385篇
  2019年   400篇
  2018年   603篇
  2017年   577篇
  2016年   624篇
  2015年   475篇
  2014年   554篇
  2013年   2331篇
  2012年   1013篇
  2011年   1046篇
  2010年   652篇
  2009年   611篇
  2008年   841篇
  2007年   838篇
  2006年   728篇
  2005年   671篇
  2004年   631篇
  2003年   578篇
  2002年   607篇
  2001年   1274篇
  2000年   1263篇
  1999年   869篇
  1998年   337篇
  1997年   325篇
  1996年   293篇
  1995年   260篇
  1992年   693篇
  1991年   628篇
  1990年   666篇
  1989年   597篇
  1988年   580篇
  1987年   542篇
  1986年   544篇
  1985年   529篇
  1984年   454篇
  1983年   388篇
  1982年   274篇
  1979年   395篇
  1978年   327篇
  1977年   271篇
  1975年   361篇
  1974年   447篇
  1973年   412篇
  1972年   372篇
  1971年   334篇
  1970年   295篇
  1969年   357篇
  1968年   398篇
  1967年   340篇
  1966年   327篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
151.
Ceci and Liker (1986b) presented data that they contended shows two things: (a) Handicapping harness races is a cognitively complex undertaking that can be captured by a multiple regression model, and (b) neither overall skill at handicapping nor the complexity of the mental model used is related to standard measures of intelligence. The first contention is not at issue. But the second contention, that handicapping performance is unrelated to IQ, is not supported by the data presented; in fact, the opposite conclusion seems more likely. The purpose of this comment is to point out errors frequently made in individual-differences research concerning population definition, sample selection, dependent and independent variable reliability and validity and interpretation of results.  相似文献   
152.
Seven severely nonfluent aphasics and one relative or close friend were investigated in an interview situation. The conversation was videotaped and analyzed for the use of nonverbal communication between aphasic and partner. The results indicate that the group of aphasics used significantly more frequently and for a significantly longer period of time nonverbal channels of communication than their healthy partners. The aphasic patients also used significantly fewer speech-focused movements and significantly more codified gestures. Nonverbal elements were more frequently used as speech substitutes by the group of aphasics.  相似文献   
153.
Sprague-Dawley rats drank sweetened (3% dextrose + 0.144% saccharin, w/v) or unflavored water for 18 days and subsequent pain reactivity was assessed using a hot plate. Compared to the rats that consumed unflavored water, the rats that consumed sweet water responded more quickly on the hot plate indicating that their threshold for pain was lowered. Another group of rats given identical exposure to the fluids had their brains prepared for measuring opiate receptor binding using the delta-receptor ligand [3H]D-Ala-D-Leu-enkephalin ([3H]DADLE) and the mu-receptor selective ligand [3H]Tyr-D-Ala-Gly-MePhe-Gly-ol ([ 3H]DAGO). Binding of these opiates to mu- and delta-receptors in the cerebral cortex, striatum, hippocampus, hypothalamus, brain stem, and remaining brain regions was the same for the rats that drank sweet fluids and those that drank unflavored water. These findings suggest that drinking sweet fluids lowers pain thresholds but does not alter mu- and delta-receptors.  相似文献   
154.
Summary The interactive-activation model postulates (a) that activation at the letter level leads automatically to activation at the word level, (b) that the word-superiority effect reflects reactivation of letters by the word they spell, and (c) that subjects identify words on the basis of information obtained from separate letter-position channels. In the first two experiments, we showed words in upper, lower, or mixed case: the word-superiority effect was reduced when words were presented in mixed-case letters, presumably because extra-letter information is lost with mixed-case presentation; i.e., postulate (c) is wrong. The third experiment showed that when the letters of a word are rotated 180° subjects can identify the letters without producing a word-superiority effect; i.e., one of postulates (a) and (b) is wrong. In Experiments 4 and 5, we trained subjects to name words presented in inverted letters; training was more effective when subjects could exploit bigram information in addition to letter-channel information; i.e., reading inverted text is based on extra-letter-feature information, not on a general skill in rotating letters. Taken together, our data deny three of the interactive-activation model's major postulates. We offer some suggestions for future versions of the model. Electronic mail: Userid: MEWHORTD; Nodeid: QUCDN; Domain: BITNET  相似文献   
155.
This research was designed to investigate development and behavioral mediation in lines of ICR mice that have been selectively bred for aggressive behavior. General behavioral reactivity and behavioral immobility have been implicated as potential mediators by prior analyses of preattack interactions. To evaluate the separate roles of these dispositions, the emergence of attacks in genetically selected lines was tracked for 11 years by three levels of analysis: over successive generations, over development, and over dyadic interactions. Convergent outcomes were observed in all three levels with respect to two findings: (a) Robust line differences were obtained in attack behaviors, and (b) strong associations were found between line differences in attacks and line differences in behavioral immobility. Conversely, all three levels of analysis indicated a weak and inconsistent association between line differences in attacks and measures of social and nonsocial reactivity.  相似文献   
156.
When given a choice between two mashes of equal caloric density but differing flavors, rats (Rattus norvegicus) show a robust preference for the flavor previously associated with a higher calorie food. This finding suggests that rats may identify food quality by sensory cues such as taste. Our initial attempt to show this effect in the golden Syrian hamster (Mesocricetus auratus) failed, apparently because of this species's tendency to store both high- and low-calorie mashes in their cheek pouches during conditioning trials. Initially we attempted to circumvent this seeming morphological constraint on learning by presenting low- and high-calorie mashes on alternate days. This procedure too failed to produce evidence of flavor-caloric learning, although this procedure produced robust learning in another rodent, the Mongolian gerbil (Meriones unguiculatus). Another method of preventing cheek pouching--concurrently presenting low- and high-calorie liquid diets--was more successful; then, hamsters showed clear evidence of flavor-caloric learning. Thus, although flavor-caloric learning is demonstrable in species of rodent besides the rat, the circumstances under which it occurs vary.  相似文献   
157.
We trained budgerigars by operant conditioning to discriminate among a set of contact calls in a same-different task and analyzed response latencies from this task by using multidimensional-scaling (MDS) and cluster-analysis procedures. Humans listened to the same calls and indicated the similarity between pairs of calls by a direct rating procedure. An MDS program (sindscal) was used to arrange these complex acoustic stimuli in multidimensional space reflecting perceptual organization. Multiple regression techniques were used to identify the acoustic characteristics of contact calls that were correlated with the perceptual dimensions obtained from MDS. A number of spectral characteristics (e.g., peak frequency, rate of frequency modulation, and concentration of spectral energy) emerged as important for both budgerigars and humans, but the relative salience of these cues differed for the two species. Additional tests with two groups of budgerigars--cagemates and noncagemates--showed that experience with calls can change the salience of various acoustic characteristics used for perceptual organization and individual recognition.  相似文献   
158.
It is proposed that expert knowledge can operate as a cognitive cueing structure for the acquisition and retention of new information in memory. Two experiments are reported which demonstrate that expert knowledge about football and clothing can act as mnemonic cues for the recall of information newly associated with that knowledge. In Experiment 1 expert terms from the domains of football and clothing and those neutral nouns paired with them were both better recalled by experts than by non-experts. In Experiment 2 passages containing information contrary to factual knowledge about football and clothing were recalled better by experts than by non-experts, in spite of the fact that information in the passages contradicted what the experts already knew. The results of the two experiments were interpreted as showing that expert knowledge provides mental cues that have desirable mnemonic properties such as constructibility, associability, discriminability and invertibility. Also, the interpretation of expert knowledge as a cognitive cueing structure is compared to Ausubel's ideas regarding advance organizers.  相似文献   
159.
In this interview, two counseling psychologists describe aspects of a relatively unique career counseling service that has been validated by 40 years of success in the marketplace. Composed of 3 intensive individual interviews and 15 to 25 hours of educational and psychological testing, the service assists clients in identifying and beginning pursuit of suitable educational and occupational goals. The counselors describe how they organize and sift through test results to formulate recommendations for a client's unique career circumstances, why they accept responsibility for developing and presenting concrete recommendations, and what the changes in their clients' concerns suggest about the evolution of work in the United States. Their specificity and professionalism will help counselors understand the craft of career counseling.  相似文献   
160.
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