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   32149篇
  免费   1368篇
  国内免费   18篇
  2020年   335篇
  2019年   443篇
  2018年   597篇
  2017年   567篇
  2016年   607篇
  2015年   442篇
  2014年   556篇
  2013年   2553篇
  2012年   973篇
  2011年   1096篇
  2010年   644篇
  2009年   654篇
  2008年   858篇
  2007年   869篇
  2006年   797篇
  2005年   666篇
  2004年   683篇
  2003年   641篇
  2002年   636篇
  2001年   1102篇
  2000年   1154篇
  1999年   779篇
  1998年   375篇
  1997年   321篇
  1996年   301篇
  1995年   288篇
  1992年   614篇
  1991年   588篇
  1990年   616篇
  1989年   589篇
  1988年   570篇
  1987年   504篇
  1986年   537篇
  1985年   545篇
  1984年   424篇
  1983年   403篇
  1982年   279篇
  1979年   429篇
  1978年   369篇
  1977年   274篇
  1975年   390篇
  1974年   470篇
  1973年   451篇
  1972年   420篇
  1971年   374篇
  1970年   304篇
  1969年   379篇
  1968年   440篇
  1967年   389篇
  1966年   377篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
171.
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   
172.
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   
173.
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   
174.
175.
Surviving members of the Berkeley Older Generation Study were interviewed and tested with the Wechsler Adult Intelligence Scale in 1969-1970 and again in 1983-1984, when subjects' ages ranged from 73 to 93. Health was assessed by self-reports at both measurement periods. Although many individuals showed some decline in intellectual functioning, substantial individual differences were apparent at all age levels. More than one half of the subjects showed no reliable change, and a minority showed a reliable increase in verbal scores. The role of self-reported health has increasing importance in the maintenance of intellectual functioning in advanced old age.  相似文献   
176.
177.
Differences in reproduction as well as in behavior in the presence of females were evaluated according to dominant and subordinate male rank in albino mice, in the temporary absence of each male's antagonist. Dominant males reproduced more successfully than subordinate males. Subordinate males were generally inactive, except for displacement activities, during the first 15 min they were exposed to female partners. These findings suggest that mechanisms other than male-male interference or mating order may be operating or influencing behavior and reproductive results.  相似文献   
178.
Although stress and anxiety have long been assumed to play an exacerbatory role in asthma, no study has systematically documented that daily exacerbations of asthma symptoms are related to stress and/or anxiety. In this study, 24 airways obstruction patients (12 asthmatics and 12 chronic obstructive pulmonary disease patients) were instructed to monitor the severity of daily respiratory symptoms. In addition, subjects recorded their daily anxiety level and the number and perceived impact of daily stressors. The results showed that although there were differences between high- and low-stress days for both groups, there were no differences between groups on symptom severity or between high- and low-anxiety days, as measured by the State-Trait Anxiety Inventory (STAI). Thus, although the number and impact of daily stressors were found to be directly associated with the severity of asthma symptoms, anxiety does not appear to have a direct role in the exacerbation of asthma. The findings failed to support the anxiety theory of asthma but provided an explanation for the poor results obtained in previous treatment studies which employed anxiety management with asthmatics.  相似文献   
179.
180.
In this study, the relations among depression, anxiety, and neuroticism measured by self-report questionnaires were investigated. Subjects were 207 psychiatric patients. High correlations were found among self-report scales purporting to measure depression, anxiety, and neuroticism. Results of a content analysis showed considerable overlap among these scales. A division of items into six content categories did not result in lower correlations compared to the original scales.  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