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   2524篇
  免费   287篇
  国内免费   208篇
  2024年   4篇
  2023年   45篇
  2022年   28篇
  2021年   49篇
  2020年   108篇
  2019年   148篇
  2018年   107篇
  2017年   150篇
  2016年   125篇
  2015年   80篇
  2014年   106篇
  2013年   413篇
  2012年   74篇
  2011年   112篇
  2010年   62篇
  2009年   136篇
  2008年   155篇
  2007年   145篇
  2006年   97篇
  2005年   116篇
  2004年   102篇
  2003年   90篇
  2002年   71篇
  2001年   77篇
  2000年   57篇
  1999年   31篇
  1998年   47篇
  1997年   37篇
  1996年   33篇
  1995年   56篇
  1994年   20篇
  1993年   11篇
  1992年   13篇
  1991年   6篇
  1989年   5篇
  1988年   10篇
  1987年   3篇
  1985年   8篇
  1984年   11篇
  1983年   12篇
  1982年   5篇
  1981年   7篇
  1980年   12篇
  1979年   9篇
  1978年   7篇
  1977年   8篇
  1976年   3篇
  1975年   2篇
  1974年   4篇
  1973年   1篇
排序方式: 共有3019条查询结果,搜索用时 15 毫秒
51.
本文运用个案研究方法 ,从人类理性的角度分析了企业在不同的生产经营条件下的目标设置方式 ,发现不确定性和目标难度对管理者的目标设置过程有很大的影响。在确定的 ,且任务较容易的情况下 ,目标设置是以一种与理性期望模型相一致的方式进行的 ,而在高度不确定的条件下 ,管理者则倾向于采用渐进适应的模式设置目标。对管理者的经营活动作进一步深入的分析发现 ,在高难度的任务目标情景中 ,决策者更多地从战略的层次 ,而不是从具体的层次上寻求实现目标的途径 ,从而提出了目标难度与实绩的“策略搜索层次”假设  相似文献   
52.
对听觉条件下中文字词劣效果的问题进行了实验考察,结果发现:在文章听点作业中,被试对高、低频目标字词语音的正误判断量存在着显著性差别,前者较后者成绩差,表现出字词劣效果的现象;在单字词的听点作业中,未发现被试对高、低频目标字词语音正误判断量方面的显著性差别;无论在文章还是单字词的听点作业中,被试对高、低频目标字词语音的正误判断量均比较低下,表明语音知觉的范畴性特征对字词语音的辩认准确性具有较大影响。  相似文献   
53.
The meaning and properties of a commonly used index of reliability, S/L,were examined critically. It was found that the index does not reflect any conventional concept of reliability. When used for an identical behavioral observation session, it is not statistically correlated with other reliability indices. Within an observation session, the standardizing measure of Lis beyond the control of the investigator. Furthermore, the reason for the choice of Las the standard is unclear. The role of chance agreement in S/Lis not known. The exact interpretation of the index depends on which observer reports L.Overall the conceptual and mathematical meaning of S/Lis dubious. It is suggested that the S/Lindex should not be used until its nature is shown to be a measure of reliability. Other approaches such as the intraclass correlations and generalizability coefficients should be used instead.The authors are indebted to Johnny Matson for his critique of an earlier version of this paper.  相似文献   
54.
55.
Weight and height data from two studies were recomputed, and original data were computed using a Weight Index formula that accounts for the interaction of actual weight/height changes in growing children and compares this ratio with that of normed weight/height ratios for equal-aged children. Recomputing the data of one study showed that the Weight Index is a more sensitive procedure for assessing long-term behavioral treatment of obesity for girls than weight alone. Recomputing the data of a second study showed that the Weight Index formula is consistent for boys and girls and is a more sensitive procedure for assessing long-term effects of a variety of medical treatments for obesity than the Ponderal Index or weight alone. Computation of the data for 17 “normal” children in a preschool class showed a zero Weight Index score before and after a six-month interval elapsed without treatment. The procedure may be useful in assessing ponderosity or anorexia over intervals of six months or more with growing children or difference between actual and normed weight over shorter intervals.  相似文献   
56.
57.
Two hypotheses were tested about how young children answer questions with the quantifiers all and some: (a) that children use syntactic cues in determining which noun phrase is quantified, and (b) that children evaluate a some-statement as part of evaluating an all-statement. To test these hypotheses, the same group of 60 4- to 7-year-olds were asked four contrasting types of quantitative questions. The results indicated that children can use syntactic cues under some presentation conditions. However, there was no evidence for an asymmetry between the all-and some-questions. A model of how young children might answer quantitative questions was then considered.  相似文献   
58.
Clinical and autopsy studies were made on a right-handed man who had central deafness and subcortical motor aphasia, and the literature on central deafness and on subcortical motor aphasia was analyzed. Central deafness is due to bilateral destruction of the primary auditory cortex. It is sometimes difficult to distinguish from word deafness and from auditory agnosia, which are due to pathology in other parts of the temporal lobes. There is almost always some preserved hearing in central deafness, possibly from some auditory pathway other than the classical pathway. In this patient the subcortical motor aphasia was due to bilateral destruction of the motor cortex for the mouth and throat. In some other cases subcortical motor aphasia was due to the same pathology that usually causes Broca's aphasia; in these cases the unexpected preservation of writing was perhaps related to some difference in how language functions were organized in the brain.  相似文献   
59.
The capacity to selectively attend to only one of multiple, spatially separated, simultaneous sound sources—the “cocktail party” effect—was evaluated in normal subjects and in those with anterior temporal lobectomy using common environmental sounds. A significant deficit in this capacity was observed for those stimuli located on the side of space contralateral to the lobectomy, a finding consistent with the hypothesis that within each anterior temporal lobe is a mechanism that is normally capable of enhancing the perceptual salience of one acoustic stimulus on the opposite side of space, when other sound sources are present on that side. Damage to this mechanism also appears to be associated with a deficit of spatial localization for sounds contralateral to the lesion.  相似文献   
60.
Performance maintained under concurrent schedules consisting of a variable-interval avoidance component and a variable-interval positive-reinforcement component was studied in three human subjects using points exchangeable for money as the reinforcer. The rate of responding in the avoidance component increased, and the rate of responding in the positive-reinforcement component declined, as a function of the frequency of point-losses avoided in the avoidance component. The performance of all three subjects conformed to equations proposed by Herrnstein to describe behavior in concurrent schedules. The logarithms of the ratios of the response rates in the two components, and the logarithms of the ratios of the times spent in the two components, were linearly related to the logarithms of the ratios of the frequency of loss avoidance in the avoidance component to the frequency of reinforcement in the positive-reinforcement component. When a changeover delay of 5.0 sec was imposed, the slopes of the linear functions were close to 1.0 in the case of two subjects, whereas the third subject exhibited significant undermatching. For two subjects the changeover delay was then reduced to 2.0 sec; in both cases the slopes of the linear functions were lower than under the 5.0-sec condition. One subject participated in a third phase, in which no changeover delay was imposed; there was a further reduction in the slopes of the linear functions.  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