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   19575篇
  免费   415篇
  国内免费   7篇
  19997篇
  2021年   160篇
  2020年   277篇
  2019年   281篇
  2018年   396篇
  2017年   426篇
  2016年   421篇
  2015年   320篇
  2014年   352篇
  2013年   1527篇
  2012年   645篇
  2011年   733篇
  2010年   446篇
  2009年   418篇
  2008年   571篇
  2007年   543篇
  2006年   463篇
  2005年   411篇
  2004年   418篇
  2003年   370篇
  2002年   393篇
  2001年   741篇
  2000年   756篇
  1999年   507篇
  1998年   218篇
  1997年   199篇
  1996年   159篇
  1995年   157篇
  1993年   165篇
  1992年   384篇
  1991年   347篇
  1990年   369篇
  1989年   354篇
  1988年   342篇
  1987年   309篇
  1986年   326篇
  1985年   327篇
  1984年   259篇
  1983年   220篇
  1979年   205篇
  1978年   175篇
  1975年   197篇
  1974年   260篇
  1973年   208篇
  1972年   213篇
  1971年   182篇
  1970年   157篇
  1969年   203篇
  1968年   212篇
  1967年   171篇
  1966年   197篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
871.
872.
The effectiveness of a domain-specific latent semantic analysis (LSA) in assessing reading strategies was examined. Students were given self-explanation reading training (SERT) and asked to think aloud after each sentence in a science text. Novice and expert human raters and two LSA spaces (general reading, science) rated the similarity of each think-aloud protocol to benchmarks representing three different reading strategies (minimal, local, and global). The science LSA space correlated highly with human judgments, and more highly than did the general reading space. Also, cosines from the science LSA spaces can distinguish between different levels of semantic similarity, but may have trouble in distinguishing local processing protocols. Thus, a domain-specific LSA space is advantageous regardless of the size of the space. The results are discussedin the context of applying the science LSA to a computer-based version of SERT that gives online feedback based on LSA cosines.  相似文献   
873.
Representing properties locally   总被引:2,自引:0,他引:2  
Theories of knowledge such as feature lists, semantic networks, and localist neural nets typically use a single global symbol to represent a property that occurs in multiple concepts. Thus, a global symbol represents mane across HORSE, PONY, and LION. Alternatively, perceptual theories of knowledge, as well as distributed representational systems, assume that properties take different local forms in different concepts. Thus, different local forms of mane exist for HORSE, PONY, and LION, each capturing the specific form that mane takes in its respective concept. Three experiments used the property verification task to assess whether properties are represented globally or locally (e.g., Does a PONY have mane?). If a single global form represents a property, then verifying it in any concept should increase its accessibility and speed its verification later in any other concept. Verifying mane for PONY should benefit as much from having verified mane for LION earlier as from verifying mane for HORSE. If properties are represented locally, however, verifying a property should only benefit from verifying a similar form earlier. Verifying mane for PONY should only benefit from verifying mane for HORSE, not from verifying mane for LION. Findings from three experiments strongly supported local property representation and ruled out the interpretation that object similarity was responsible (e.g., the greater overall similarity between HORSE and PONY than between LION and PONY). The findings further suggest that property representation and verification are complicated phenomena, grounded in sensory-motor simulations.  相似文献   
874.
A group of high school juniors and a group of high school seniors in Izmir, Turkey completed measures of test anxiety, coping skills, and perceived health status both before and after a major exam period. Students with high test anxiety used less effective coping mechanisms and tended to have poorer perceptions of their health. Prior to the exams, juniors displayed higher test anxiety and used less effective coping mechanisms than seniors. After the exam periods, improvements were seen for both age groups on perceived health, but scores of younger students remained significantly higher than scores of seniors on one of the key measures of test anxiety. Results of the study lend support to those of previous studies done in other cultural contexts, and findings have implications for the development of interventions designed to help students cope with stress.  相似文献   
875.
Two experiments investigated the mechanisms underlying analogical transfer in the clue-word reading task developed by Goswami and her colleagues. Across both experiments, an equivalent number of "analogy" responses were made regardless of whether the clue word was seen or just heard. In addition, the number of "analogy" responses to words sharing both orthographic and phonological overlap with the clue words was no greater than that shown to words sharing only pronunciations. These results provide no evidence for the view that beginning readers make genuine orthographic-based analogies. Instead, the findings are interpreted within a framework in which phonological priming, in combination with the children's own partial decoding attempts based on limited orthographic knowledge, account for their performance on the clue-word task. It is concluded that the extent to which beginning readers make orthographic analogies is overestimated and as a consequence, theories that emphasize the importance of orthographic analogy as a mechanism driving the development of early reading skills need to be questioned.  相似文献   
876.
On the basis of three experiences, 9-month-olds recall specific events after one month. We tested whether multiple experiences are necessary, or merely facilitative, of 9-month-olds' long-term recall. In two experiments, using deferred imitation, infants were exposed to multi-step sequences either one time, two times, or three times prior to a one-month delay. In Experiment 1, regardless of the number of experiences, infants did not demonstrate recall. In Experiment 2, infants were tested on and reexposed to the events after one week; recall was tested again one month later. Performance after 1 week in Experiment 2 was greater than performance after one month in Experiment 1. Moreover, presumably as a function of reexposure after one week, infants recalled the individual actions of the events one month later. Infants in the three-experience condition also evidenced ordered recall after one month. Implications for the developmental status of the neural substrate supporting long-term recall are discussed.  相似文献   
877.
In a study among 72 nurses, the affective consequences of social comparison were examined and related to neuroticism (N) and to social comparison orientation (SCO). Participants were confronted with a bogus interview with an upward versus a downward comparison target. Positive affect and identification were higher, and negative affect was lower, in the upward than in the downward comparison condition. Independent of their SCO, the higher individuals were in N, the less they identified with the upward comparison target, the more they identified with the downward comparison target, and the less positive affect they showed following confrontation with the upward comparison target. In contrast, independent of their level of N, the higher individuals were in SCO, the more negative affect they showed following confrontation with the downward comparison target. The effects on negative affect stayed the same when controlling for positive affect, and the effects on positive affect stayed the same when controlling for negative affect. These effects were also obtained when perceived direction was used as a predictor instead of the experimentally manipulated direction. It is concluded that, although N and SCO are correlated, these variables seem to have independent and distinct effects upon the responses to social comparison information.  相似文献   
878.
Adding material that provided an associative connection to a pun enhances perceived humor, as shown in a previous series of studies. Because those results had been based on one-sentence statements that may have relied, in part, on brevity for humor, the purpose of the present study was to evaluate reactions to context and puns (mostly spoonerisms) with more lengthy material to add generality to those findings. Three within-subject studies were conducted in which short fables were manipulated systematically such that the final sentence was or was not a pun and contextual information pertaining to both meanings of the pun was or was not present in the body of the stories. Results showed that the pun itself was a powerful contributor to perceived humor and cleverness and that contextual information amplified those perceptions. Arousal, surprise, and detection of appropriate incongruity are discussed.  相似文献   
879.
A theoretical framework based on the concepts and tools of nonlinear dynamical systems is advanced to account for both the persistent and transitory changes traditionally shown for the learning and development of motor skills. The multiple time scales of change in task outcome over time are interpreted as originating from the system's trajectory on an evolving attractor landscape. Different bifurcations between attractor organizations and transient phenomena can lead to exponential, power law, or S-shaped learning curves. This unified dynamical account of the functions and time scales in motor learning and development offers several new hypotheses for future research on the nature of change in learning theory.  相似文献   
880.
We investigated prospectively the relationship of Type A behavior and its subcomponents with cardiac mortality and recurrent nonfatal cardiac events in a 2-yr. follow-up of 90 patients [69 men and 21 women, M age=56.4 yr., SD=8.4] after acute coronary syndrome. Type A behavior was assessed via the general Bortner Type A Index. Each patient completed the Bortner's scale before hospital discharge. During the first 2-yr. follow-up, there were 14 cardiac deaths among patients with myocardial infarction. 8 patients had recurrent cardiac events and were hospitalized, and 19 patients had an effort-induced angina pectoris. Patients with acute myocardial infarction who died during follow-up had a significantly lower Bortner score than patients with a secondary cardiac event. Bortner scores of patients with acute myocardial infarction who died indicated Type B behavioral patterns. Mortality was significantly higher in the patients classified as showing Type B (21.8%) behavior than in the patients classified as showing Type A (12.0%) behavior. Patients with a secondary cardiac event had more common Type A behavior patterns and higher Bortner scores than patients without a secondary cardiac event. The items on Bortner's scale "very competitive, ever rushed, tries to do too many things at once, fast in daily activities and expresses feelings" were inversely associated with cardiac deaths. These findings suggest that patients with acute coronary syndrome classified by scores on the Bortner scale as Type B behavior have a greater probability of death, and patients classified on the Bortner scale as Type A behavior have a greater probability of secondary cardiac events during follow-up. This finding may have implications for the treatment of patients with acute coronary syndrome. The inferior survival of patients with Type B personalities argues against attempts to modify Type A behavior in postinfarction patients.  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