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   2883篇
  免费   102篇
  国内免费   2篇
  2020年   45篇
  2019年   60篇
  2018年   52篇
  2017年   66篇
  2016年   71篇
  2015年   63篇
  2014年   61篇
  2013年   336篇
  2012年   102篇
  2011年   117篇
  2010年   76篇
  2009年   70篇
  2008年   96篇
  2007年   99篇
  2006年   100篇
  2005年   92篇
  2004年   93篇
  2003年   83篇
  2002年   104篇
  2001年   50篇
  2000年   41篇
  1999年   47篇
  1998年   34篇
  1997年   39篇
  1996年   41篇
  1995年   49篇
  1994年   33篇
  1993年   46篇
  1992年   31篇
  1991年   42篇
  1990年   34篇
  1989年   31篇
  1988年   43篇
  1987年   35篇
  1986年   28篇
  1985年   43篇
  1984年   34篇
  1983年   36篇
  1982年   32篇
  1981年   36篇
  1980年   30篇
  1979年   31篇
  1978年   31篇
  1977年   37篇
  1976年   33篇
  1975年   25篇
  1974年   25篇
  1973年   20篇
  1970年   16篇
  1967年   20篇
排序方式: 共有2987条查询结果,搜索用时 15 毫秒
131.
While measurement of temperature as an index of circadian rhythmicity is not a difficult task with infrahuman subjects, long-term monitoring of deep body temperature with human subjects poses numerous measurement and safety problems. A preparation is described that is highly accurate, inexpensive, chronic, comfortable, and eliminates safety problems associated with more traditional methods of temperature measurement.  相似文献   
132.
Procedures for observing, coding, and analyzing parent-infant interactions are described. Sample data are presented to illustrate the outcome of these procedures and the manner in which developmental issues can be addressed using the hardware and software systems described.  相似文献   
133.
134.
A total of 400 children at ages 5, 9, and 12 years were given a component selection task with stimuli differing in color and shape. Relative salience of these two stimulus components was manipulated across subjects in two ways: the standard shapes and colors from previous studies were compared with standard shapes in fluorescent colors, and the latter materials were compared with nonsense shapes in fluorescent colors. While fluorescence of color had little effect, the replacement of standard shapes with nonsense figures caused attention to be redirected from shape to color as the primary cue for learning. This effect was more pronounced at age 9 than at age 5. Apparently there is a greater tendency for older than for younger children to withdraw attention from a normally dominant component such as shape, when it is advantageous to adopt another feature such as color as the primary functional cue. An additional variable was integration of components (color within shape vs color as background for shape). Integration produced generally greater attention to color but did not affect the general pattern of salience effects.  相似文献   
135.
Two experiments examined the role of information storage and frequency estimation processes in a simple decision task. On each trial from one to five simultaneous sequences of information were presented, and subjects were required to monitor and respond to each sequence. In one study independent groups of subjects gave decisions, recognition responses. or frequency judgments. In a second study recall responses were obtained from subjects as part of the decision and frequency judgment tasks. Changes in performance as the number of simultaneous sequences increased suggested an independence of decisions from memory for specific information. Performance on the decision and frequency judgment tasks exceeded at times that which was possible on the basis of specific information available. Other data suggested that subjects in the frequency estimation tasks maintained an accurate frequency count when possible, but in the decision task kept little more than a record of their currently favored hypothesis. When direct counting was prevented in the second experiment. performance in the two tasks was not significantly different, suggesting that the two processes are very similar under such conditions.  相似文献   
136.
137.
138.
139.
OBJECTIVE: The premise that pessimistic health appraisals compromise well-being whereas optimistic appraisals are compensatory was examined in a longitudinal study of 232 community-dwelling older adults (ages 79-98 years). DESIGN: Subjective health (SH) appraisals were contrasted with objective health (OH) to identify realists, whose ratings were congruent (SH = OH), distinguishing them from health pessimists (SH < OH) and health optimists (SH > OH), whose ratings were incongruent. Analyses of covariance were used to examine group differences 2 years later on well-being and health care. MAIN OUTCOME MEASURES: Outcome measures were psychological well-being (life satisfaction, positive and negative emotions), functional well-being (objective and perceived physical activity, activity restriction), and health care (health care management, hospital admissions, length of hospital stays). RESULTS: Compared with realists, pessimists had significantly poorer outcomes and optimists had better outcomes. Because perceived control (PC) was weaker among pessimists and stronger among optimists, supplemental analysis determined whether PC differences explained these findings. When accounting for PC, many pessimism and optimism effects became nonsignificant, yet effects on functional well-being remained unchanged. CONCLUSION: Findings have implications for older adults at risk of functional decline.  相似文献   
140.
Recent experience with attempts to test relatively simple patterns such as three-tone sequences in a traditional dichotic-listening paradigm indicates that when such sequences are used for both target and contralateral interference, performance tends to be low in both ears and not useful for measuring or comparing ear advantages in various target conditions. It is reported that tests with a variety of sounds presented contralaterally to three-element patterns show that several such sounds can (1) allow performance in at least one ear to remain above floor values, (2) result in performance in at least one ear that is below ceiling, and (3) reveal ear advantages that are similar in direction and magnitude to those seen with the traditional dichotic paradigm.  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