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   4976篇
  免费   73篇
  国内免费   106篇
  2023年   20篇
  2022年   19篇
  2021年   29篇
  2020年   33篇
  2019年   20篇
  2018年   138篇
  2017年   116篇
  2016年   204篇
  2015年   114篇
  2014年   62篇
  2013年   98篇
  2012年   303篇
  2011年   284篇
  2010年   58篇
  2009年   63篇
  2008年   67篇
  2007年   74篇
  2006年   86篇
  2005年   1346篇
  2004年   670篇
  2003年   456篇
  2002年   139篇
  2001年   29篇
  2000年   11篇
  1999年   25篇
  1994年   11篇
  1992年   26篇
  1991年   43篇
  1990年   59篇
  1989年   45篇
  1988年   26篇
  1987年   41篇
  1986年   37篇
  1985年   32篇
  1984年   25篇
  1983年   19篇
  1979年   32篇
  1978年   10篇
  1976年   10篇
  1975年   29篇
  1974年   32篇
  1973年   30篇
  1972年   25篇
  1971年   25篇
  1970年   17篇
  1969年   19篇
  1968年   16篇
  1967年   17篇
  1966年   16篇
  1965年   7篇
排序方式: 共有5155条查询结果,搜索用时 15 毫秒
41.
Aged rats with extensive prior training on the radial maze retain the capacity for accurate spatial working memory (WM) for at least 3 months without practice. To investigate the temporal limits of this influence of prior experience we compared the reacquisition of spatial WM by a group of experienced 21.5-month-old rats to the original acquisition by naive 3-month-old rats. The aged rats had received 225 radial maze tests between 3 and 11 months of age. Despite 10 months without practice the old rats rapidly reacquired critical performance. Their reacquisition was markedly superior to original learning by the young rats, even when delays as long as 5 h were imposed between the rats' fourth and fifth choices during the daily tests in the eight-arm maze. Additional tests showed that neither young nor old rats employed a response strategy to maintain accurate spatial WM performance. Experience clearly confers long-lived protection against the otherwise deleterious effects of aging on spatial WM, but the mechanism by which this influence arises is unknown.  相似文献   
42.
The ability to think of a previously studied item has often been shown to be impaired when, in one way or another, the extraitem context is changed from study to test. In a series of five experiments, such impairment is induced in a somewhat different way. A fragment (e.g. r-i--rop) of a just-studied word (raindrop) is shown to be less readily completed if it is presented bit by bit (r------p, r----r-p, r-i--r-p, r-i--rop) rather than all at once (Experiments 1, 3, 4, and 5). No such effect is found if the word has not been studied beforehand (Experiments 2, 3, 4, and 5). This pattern of results occurs even when fragments of studied and nonstudied words occur in the same test and under conditions in which subjects cannot tell whether a given fragment is of a studied or nonstudied word (Experiments 4 and 5). In addition, for words that have been studied beforehand, the impairment is shown to increase systematically with the number of steps involved in the presentation of the word fragment (Experiment 3) and also to persist when the time allowed for completion of the final version of the fragment is increased from 4 s to a full minute (Experiment 5).  相似文献   
43.
The somatic and psychosocial development of 80 subjects with manifest affective-phasic psychoses is studied retrospectively and compared with that of an identically sized control group consisting of neuropsychiatrically healthy subjects. Statistically significant differences were found particularly in the answers to questions dealing with social situation and social adaptability. Achievement at school and vocational qualifications were lower among the parents of the patients than among those of the healthy subjects. Characteristic features of the patients' childhood and adolescence were transient depression, often for no apparent cause, and maladaption, and vocational wishes were fulfilled less often than among the controls. The patients experienced greater difficulty in settling in to a new group due to their contact difficulties.  相似文献   
44.
By 48 patients with Wilson's disease the brainstem acoustic evoked potentials were stated. There were 35 pathological findings (73%), 13 were normal (27%). The waves, determined by the middle and upper brainstem (Pons and Mesencephalon) showed most of all pathological changes. Those patients with forms of Wilson's disease called Pseudoskelerose and Pseudoparkinson showed the most pathological findings. But one could watch these findings by about 30% of patients in preclinical stage. This method can possibly be used for early detection of disorders of brainstem functions and in the same way it can be used for control of treatment by patients in preclinical stage.  相似文献   
45.
Dominant group members often are not aware of the privileges they benefit from due to their dominant group membership. Yet individuals are members of multiple groups and may simultaneously occupy multiple categories of dominance and marginality, raising the question of how different group memberships work in concert to facilitate or inhibit awareness of multiple forms of privilege. Examining awareness of privilege is important as awareness may be linked to action to dismantle systems of privilege that maintain oppression and inequality. Grounded in intersectional scholarship, in this study we examined how occupying intersecting categories of race/ethnicity, gender, and religion corresponded to an awareness of White, male, and Christian privilege. In a sample of 2321 Midwestern college students, we demonstrated that students from marginalized groups broadly reported greater awareness of all forms of privilege than students from dominant groups, and the difference between marginalized and dominant groups was most pronounced when the specific group category (e.g., gender) aligned with the type of privilege (e.g., male privilege). We also tested interactions among race/ethnicity, gender, and religion, only finding an interaction between race/ethnicity and religion for awareness of White and male privilege. These findings helped to clarify that multiple group memberships tended to contribute to awareness as multiple main effects rather than as multiplicative. Finally, we examined mean differences among the eight intersected groups to explore similarities and differences among groups in awareness of all types of privilege. Taken together, these findings quantitatively demonstrate the ways in which group memberships work together to contribute to awareness of multiple forms of privilege. We discuss study limitations and implications for community psychology research and practice.  相似文献   
46.
自闭症谱系障碍(Autism Spectrum Disorder, ASD)表现为社会交往困难以及重复刻板兴趣或行为。社交动机理论提出ASD个体是由于社交动机缺乏导致的社交障碍。目前该理论缺乏理论元素及结构关系的系统论证, 及基于此理论的低龄ASD儿童群体的研究证据。本研究拟采用心理实验法、眼动及近红外脑成像技术, 探索低龄ASD儿童早期社交奖赏、社交定向异常眼动标记及眶额叶脑区活动的神经机制。此外, 通过音乐奖赏强化学习的干预方式改善该理论的核心元素(社交奖赏), 观测能否改善ASD儿童的社交动机。本研究的开展有望对该理论进行系统验证, 并形成改善社交行为的潜在干预方案。  相似文献   
47.
跨期选择是对不同时间点的得失的权衡与选择。伊索寓言《蚂蚁和蚱蜢》假借群居型昆虫的跨期选择偏爱暗喻投资未来的慢策略比只顾眼前的快策略更利于生存。用跨期选择领域通用的语言解读这一寓言便是:选择大而迟选项的蚂蚁比选择小而早选项的蚱蜢更可能扛过严冬而生存下来。为了探索何种跨期选择策略更有助于我们扛过疫情,本研究调查了亚非欧美大洋洲这5大洲18个国家共计26355名受测者对混合得失双结果的跨期选择偏爱,测量了人们平时和疫时跨期选择偏爱的变易程度(2类变易的程度指标),以及人们自评的扛疫成效。跨文化比较结果的主要发现是:不同通货的选择变易程度(指标1)和不同时期的选择变易程度(指标2)能联合预测中国/新加坡文化圈国民的自评扛疫成效;不同时期的选择变易程度(指标2)也可以单独预测印度/马来西亚/菲律宾/尼日利亚文化圈国民的自评扛疫成效;这2类选择偏爱变易的程度指标不能预测其他文化圈国民的自评扛疫成效(或者预测方向和假设相反)。基于易经“穷则变,变则通”的要旨和跨国比较的发现,我们认为:面临历史危机时善于变通的特长抑或成就了中华民族特有的竞争优势;在应对危机时,与中国文化距离越相近的国家或民族抑或也能...  相似文献   
48.
49.
50.
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