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   24087篇
  免费   821篇
  国内免费   11篇
  2020年   231篇
  2019年   237篇
  2018年   364篇
  2017年   408篇
  2016年   408篇
  2015年   265篇
  2014年   341篇
  2013年   1832篇
  2012年   663篇
  2011年   721篇
  2010年   460篇
  2009年   421篇
  2008年   616篇
  2007年   602篇
  2006年   551篇
  2005年   499篇
  2004年   486篇
  2003年   446篇
  2002年   515篇
  2001年   761篇
  2000年   767篇
  1999年   585篇
  1998年   271篇
  1997年   232篇
  1992年   464篇
  1991年   424篇
  1990年   460篇
  1989年   431篇
  1988年   413篇
  1987年   412篇
  1986年   424篇
  1985年   435篇
  1984年   360篇
  1983年   320篇
  1982年   251篇
  1981年   237篇
  1979年   403篇
  1978年   291篇
  1977年   269篇
  1976年   248篇
  1975年   361篇
  1974年   399篇
  1973年   367篇
  1972年   342篇
  1971年   298篇
  1970年   271篇
  1969年   338篇
  1968年   374篇
  1967年   340篇
  1966年   343篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
211.
212.
Two experiments are reported which investigated how subject gender and time-of-day influenced the estimation of duration and the perception of task-related mental workload. In the first experiment, 24 subjects performed a filled time-estimation task in a constant blacked-out, noise-reduced environment at 0800h, 1200h, 1600h, and 2000h, respectively. In the second experiment, 12 different subjects performed an unfilled time estimation task in similar conditions at 0900h, 1400h, and 1900h. At the termination of all experimental sessions, participants completed the NASA Task Load Index workload assessment questionnaire as a measure of perceived mental workload. Results indicated that physiological response, reflected in body temperature change, followed an expected pattern of sequential increase with time-of-day. However, estimates of duration and the perception of mental workload showed no significant effects for time-of-day. In each of the experiments there were significant differences in time estimation and mental workload response contingent on the gender of the participant. These results are interpreted in light of the previous positive findings for circadian fluctuation in performance efficiency and the equivocal findings of a gender difference in time estimation. A unifying account of these collective results is given based on gender by time-of-day interactional effects. An earlier version of this paper was presented at the 32nd Annual Meeting of the Human Factors Society, Anaheim, CA, October, 1988.  相似文献   
213.
The authors used a correlated motion paradigm to investigate the effects of aging and gender on motion sensitivity. In 2 experiments with a total of 50 elderly and 50 young subjects, motion thresholds were significantly higher for elderly women. The correlated motion signal, which was embedded in random motion, may have been coherent to subjects in much the same way a form is in Witkin's Embedded Figures Test (EFT). In Experiment 2, EFT scores were obtained. A significant positive relationship between motion thresholds and EFT performance was found within each age group. Although gender-related perceptual style differences may contribute to motion perception effects, the authors argue that a common neural factor contributes to performance on both the EFT and the correlated motion task.  相似文献   
214.
215.
The relationship between memories of childhood experiences (e.g., adverse parenting) and adult depression often found raises questions of interpretation. On the one hand, both laboratory studies and clinicians' experiences suggest that subjects in a depressed mood frequently show a negative bias in perceptions and memories. Negative childhood memories in depressed persons might, therefore, be interpreted as epiphenomena of depressed mood instead of etiological factors. On the other hand, memories of childhood experiences seem remarkably stable across changes in depressed mood, especially when memories are elicited by means of standardized questionnaires. In the mood and memory literature several explanations for this stability are offered. For one thing, highly structured cues to elicit memories (such as in questionnaires) are hypothesized to be less susceptible to mood bias than unstructured memory cues (such as in free recall procedures). On the other hand, resource allocation theorists suggest that childhood memories, being well established and rehearsed, are relatively impervious to mood bias no matter how they are elicited. In this study we examined whether different methods of eliciting childhood memories (i.e., free recall and questionnaire-cued) are differentially susceptible to mood bias. To this aim, we used a mood induction procedure to induce depressed, neutral, and elated mood and assessed childhood memories both before and after the mood induction using both questionnaires and free recall to elicit memories. Results suggested that memories elicited by means of free recall as well as by means of questionnaire-cued recall were susceptible to depressed and elated mood bias. The implications for research addressing the link between childhood experiences and depression are discussed.  相似文献   
216.
Elderly women in subjectively good health--free of acute illness and major sleep pathologies--who were self-identified as good (n = 22) and poor (n = 16) sleepers were compared on measures of physical health, psychological symptoms, psychosocial status, and life-style. Poor sleepers reported longer sleep latencies, less total sleep time, more nonrestorative sleep, and more daytime fatigue than did good sleepers. Sleep recordings confirmed subjective reports, with shorter total sleep times and trends for lower sleep efficiency, longer sleep latencies, and more wake-after-sleep onset among women with subjective poor sleep. Poor sleepers also were more frequent users of sedative-hypnotic medications in the past. Current medication use, alcohol and caffeine use, daytime napping, and exercise were equivalent in both groups. Psychosocial status failed to discriminate groups. Poor sleepers reported significantly more psychological symptoms than did good sleepers. The levels of both psychological symptoms and sleep disturbance were mild.  相似文献   
217.
Short-term memory for actions was investigated for young adult and elderly adult subjects with the Brown-Peterson procedure at retention intervals of 0 and 15 s. The short-term memory trials were followed by the long-term recall of the prior to-be-remembered actions. The 15-s retention interval was filled either with no activity or with 1 of 3 different interfering activities. Verbal interference had little effect on short-term memory at either age level. Actions performed in the interval either by the subjects or by the experimenter produced significantly lower recall scores at each age level, with the decrement being more pronounced for the elderly than for the young subjects. The long-term memory results indicated that successful short-term recall enhanced later long-term recall, regardless of age level.  相似文献   
218.
The Australian study investigated condom-specific assertiveness and condom use as a means of prevention infection from sexually transmitted diseases. 211 men participated including 83 homosexual men (aged 19-62 years) and 128 heterosexual men (aged 17-49) who completed a questionnaire that comprised demographic details such as age, monogamy, and sexual activity as well as attitudinal and assertiveness measures. General assertiveness was measured by the Rathus Assertiveness Schedule (RAS) which had been widely used across a wide range of social situations. Assertiveness relating specifically to situations involving condoms was measured by the Condom Assertiveness Scale (CAS). Intention to use condoms was positively related to favorable attitudes, which were related to condom-specific assertiveness for both groups. For the heterosexual men only, general social assertiveness was negatively related to attitudes toward condoms. For both groups, the condom-specific measure of assertiveness was positively correlated with attitudes toward condoms. Condom-specific assertiveness was positively related to general social assertiveness as measured by the Rathus Assertiveness Schedule for the homosexual, but not for the heterosexual men. The negative relationship between general assertiveness and attitude to condoms among the heterosexual men implies that the risk reducing behavior of condom use did not seem to accord with the perceptions of masculinity and social assertiveness among heterosexual men. Thus, female partners of such heterosexual men exhibiting negative attitudes toward condom use combined with assertiveness would have to overcome resistance to insist on the use of condoms. Recently some advertising campaigns have been directed at women. The promotion of condom use among heterosexual men has to deal with the perceptions of condom use as unmasculine behavior.  相似文献   
219.
The development of competence was studied in a longitudinal sample of 98 children, with measurement points when the children were 7, 10, and 12 years old. Competence was defined in terms of adequate adaptation to developmental tasks, both on a general and on a domain-specijic level. The general form of competence was measured by ego-resiliency, reflecting fexibility and ability to solve developmental problems Domain-specific competencies were measured by school achievement and social preference. The results showed that ego-resiliency was related to the two domain-specific competencies, although the hypothesized causal direction from general competence to specific competencies was not supported. Both domain-specific competencies were found to have a feedback effect on ego-resiliency. This feedback effect was stronger for social preference. These results suggest a transactional relationship between general and domain-specific competencies, and point to the importance of domain-specific competencies (especially social preference by the peer group) in the development of general competence in the child.  相似文献   
220.
Aristotle considers all examples, as far as they are used as rhetorical arguments, to be inductions (Rhetoric 1, 2, 8). On the other hand, he finds it worthwhile to distinguish different kinds of examples (viz., historical example, comparison, and fable). Moreover, comparisons and fables are said to be made by the orator, whereas historical examples are not (Rhetoric 2, 20, 2s). The present article attempts to explain this opposition.A close examination of what can be meant by induction reveals that this term applies differently to historical examples and to comparisons and fables. In a broader sense, all examples can be called inductions, insofar as a certain logical relation, different from the syllogistic one, obtains between conclusion and premises. This relation, however, is unable to explain why examples can serve as arguments. Applied to historical examples only, the term induction preserves its original meaning of checking samples in a number sufficient to yield generalization. In its narrow sense, induction gives a satisfactory account of how historical examples work. As for comparisons and fables — to which induction applies in a broader sense only — Aristotle fails to explain what makes them arguments. The explanation, missing in Rhetoric 2, 20, can, however, be given according to the general lines of Aristotelian dialectics and rhetorics. The main task of comparison and fable is to elaborate a so far unconsidered middle term (M) meeting the following conditions: the hearer is prepared to agree that M applies to the subject of the conclusion and that the predicate of the conclusion applies to M. All examples make use of a general proposition from which their conclusion can be inferred. Historical examples (like real inductions) produce instances, in order to confirm a proposition previously admitted as suitable premise, provided that its truth can be proved. Comparison and fables, by introducing a new middle term, try to form a premise susceptible of being admitted without proof.
La classification des exemples d'après Aristote (Rhétorique 2,20)
  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