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   22888篇
  免费   936篇
  国内免费   12篇
  2020年   230篇
  2019年   291篇
  2018年   407篇
  2017年   441篇
  2016年   472篇
  2015年   352篇
  2014年   413篇
  2013年   1856篇
  2012年   680篇
  2011年   717篇
  2010年   437篇
  2009年   402篇
  2008年   526篇
  2007年   608篇
  2006年   505篇
  2005年   470篇
  2004年   449篇
  2003年   430篇
  2002年   455篇
  2001年   756篇
  2000年   722篇
  1999年   548篇
  1998年   218篇
  1996年   226篇
  1992年   453篇
  1991年   448篇
  1990年   432篇
  1989年   406篇
  1988年   428篇
  1987年   384篇
  1986年   391篇
  1985年   394篇
  1984年   315篇
  1983年   281篇
  1982年   208篇
  1981年   211篇
  1979年   354篇
  1978年   262篇
  1977年   222篇
  1976年   205篇
  1975年   284篇
  1974年   360篇
  1973年   371篇
  1972年   290篇
  1971年   287篇
  1970年   285篇
  1969年   257篇
  1968年   353篇
  1967年   305篇
  1966年   289篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Adult-child interactions during stressful medical procedures were investigated in 43 pediatric patients videotaped during a venipuncture procedure in the course of cancer treatment. Relations among six adult behavior categories (explain, distract, command to engage in coping behavior, give control to the child, praise, and criticize/threat/bargain) and three child behavior categories (momentary distress, cry/scream, and cope) were examined using correlational and sequential analysis. Results indicated that adult distraction resulted in increased child coping and reduced momentary distress and crying. Adult explanations, although a likely response to child distress and crying, did not result in a reduction of these behaviors. Attempts to give the child control reduced child crying. Implications for clinical interventions during painful medical procedures are discussed.  相似文献   
3.
4.
Ten untreated patients with recently diagnosed Parkinson's disease (PD), 9 treated patients with more advanced pathology, and 17 matched normal controls were investigated with three reaction tasks with increasing cognitive load but identical motor requirements: simple reaction, choice reaction with indicative stimuli, and choice reaction with ambiguous stimuli. Times required until a home key was released (= reaction time) and from then until a response key was pressed (= movement time) were recorded. Estimates of pure decision time (overall response time minus movement time in a simple reaction time task) revealed a difference between advanced and early PD patients. Advanced PD patients showed an overall slowing of decision time in the reaction time tasks, but the effect of the cognitive load of the tasks on the decision time was comparable to a control group. The untreated early PD patients performed quite normally in the more simple decision tasks but showed a disproportionate slowing of decision time in tasks with higher cognitive load.  相似文献   
5.
6.
7.
The problem of representing the spatial structure of images, which arises in visual object processing, is commonly described using terminology borrowed from propositional theories of cognition, notably, the concept of compositionality. The classical propositional stance mandates representations composed of symbols, which stand for atomic or composite entities and enter into arbitrarily nested relationships. We argue that the main desiderata of a representational system—productivity and systematicity—can (indeed, for a number of reasons, should) be achieved without recourse to the classical, proposition‐like compositionality. We show how this can be done, by describing a systematic and productive model of the representation of visual structure, which relies on static rather than dynamic binding and uses coarsely coded rather than atomic shape primitives.  相似文献   
8.
Adult age differences in the consistency effect were examined in 3 experiments. The consistency effect refers to items inconsistent with expectations being better remembered than items consistent with expectations. Younger and older adults walked into an office room and viewed objects that varied in their consistency with expectation. Immediate and delayed recognition tests on item information (i.e., distractors were defined by their semantic identity) revealed that both age groups recognized unexpected items better than expected items. However, when recognition of token information was requested (i.e., distractors were defined by their physical appearance), younger adults, in contrast to older adults, exhibited consistency effects. Also, under divided attention, young adults revealed the same pattern of data as did elderly adults under full attention. The results are discussed in terms of capacity-related differences in distinctive encoding.  相似文献   
9.
We investigated motivational and cognitive processes of behavior change with respect to mammography screening. One hundred forty-two women (ages 40 and older) recruited from three worksites answered a 41-item questionnaire consisting of statements based on constructs from the transtheoretical model of behavior change. Principal-components analysis identified two factors: a six-item component representing positive perceptions of mammography (Pros) and a six-item component representing avoidance of mammography (Cons). Analysis of variance showed that Pros, Cons, and a derived Decisional Balance measure (Pros minus Cons) were associated with stage of mammography adoption. Results are consistent with applications of the model to smoking cessation. The model is also discussed as it relates to other theories of behavior change and as a general strategy for analyzing perceptual data pertinent to health-related actions and intentions for behavioral change.  相似文献   
10.
Range of electric vehicles (EVs) has long been considered a major barrier in acceptance of electric mobility. We examined the nature of how range is experienced in an EV and whether variables from other adaptation contexts, notably stress, have explanatory power for inter‐individual differences in what we term comfortable range. Forty EVs were leased to a sample of users for a 6‐month field study. Qualitative and quantitative analyses of range experiences were performed, including regression analyses to examine the role of stress‐buffering personality traits and coping skills in comfortable range. Users appraised range as a resource to which they could successfully adapt and that satisfied most of their daily mobility needs. However, indicators were found that suggested suboptimal range utilisation. Stress‐buffering personality traits (control beliefs, ambiguity tolerance) and coping skills (subjective range competence, daily range practice) were found to play a substantial role in comfortable range. Hence, it may be possible to overcome perceived range barriers with the assistance of psychological interventions such as information, training, and interface design. Providing drivers with a reliable usable range may be more important than enhancing maximal range in an electric mobility system.  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