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   14126篇
  免费   1019篇
  国内免费   423篇
  15568篇
  2024年   40篇
  2023年   211篇
  2022年   162篇
  2021年   200篇
  2020年   466篇
  2019年   447篇
  2018年   455篇
  2017年   492篇
  2016年   399篇
  2015年   290篇
  2014年   368篇
  2013年   1113篇
  2012年   238篇
  2011年   318篇
  2010年   280篇
  2009年   383篇
  2008年   427篇
  2007年   463篇
  2006年   463篇
  2005年   388篇
  2004年   331篇
  2003年   268篇
  2002年   216篇
  2001年   158篇
  2000年   127篇
  1999年   149篇
  1998年   110篇
  1997年   80篇
  1996年   77篇
  1995年   72篇
  1994年   53篇
  1993年   54篇
  1992年   56篇
  1991年   27篇
  1990年   32篇
  1989年   41篇
  1988年   25篇
  1985年   464篇
  1984年   594篇
  1983年   510篇
  1982年   574篇
  1981年   548篇
  1980年   541篇
  1979年   486篇
  1978年   539篇
  1977年   430篇
  1976年   408篇
  1975年   334篇
  1974年   341篇
  1973年   288篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
We assessed the effects of a computerized matching-to-sample procedure on the spelling performances of three students with mental retardation. Initially, the students could 1) match pictures and printed words to one another, and 2) match pictures and printed words to spoken words. However, they could not construct words to either pictures or spoken words (e.g., touch, in order, the letters s->h->o->e given the spoken-word sample Shoe). Word constructions then improved markedly after exposure to delayed constructed-response identity matching (e.g., touch the letters s->h->o->e given the printed-word sample shoe). One subject's oral and written spelling also improved. The results extend previous research by showing multiple positive effects of a computerized spelling intervention. These effects may have occurred in part because of the formation of stimulus classes among pictures, printed words, and spoken words.  相似文献   
12.
Genetic counselors have participated in the Michigan Newborn Screening Program on a contractual basis since 1988. Their role includes newborn screening education and training, newborn nursery site visits, and monitoring newborn screening in hospitals. Their impact has been to improve the quality of newborn screening services by reducing errors and increasing completion of data fields on newborn screening cards, improving hospital nursery cooperation and problem solving, and enhancing health department response to specific problems.  相似文献   
13.
Hwe Ik Zhang 《Zygon》1989,24(4):447-456
Abstract. The position and role of humanity in the world of life is examined in the light of the ontological structure of life itself. This problem is approached by considering the possible units of life representing various modes of life phenomena. I argue that the only meaningful unit of life without interposing some special external conditions is "global life" framed in a star-planet system. Any other possible unit of life exhibited by various kinds of individuals is conditional in the sense that it would leave out an essential part as "co-life." The relationship between human being and the global life should be understood in this general scheme of individual and global life. It is emphasized, however, that human being occupies a unique position in global life in the sense that humanity can promote either a cancerous situation or a healthy higher-order enhancement of the global life.  相似文献   
14.
Shu-hsien Liu 《Zygon》1989,24(4):457-468
Abstract. The traditional Chinese idea of t'ien-jen-ho-i (Heaven and humanity in union) implies that humanity has to live in harmony with nature. As science and technology progress, however, the idea appears increasingly outmoded, and it becomes fashionable to talk about overcoming nature. Ironically, though, the further science reaches the more clearly are its limitations exposed. The exploitation of nature not only endangers many life forms on earth but threatens the very existence of the human species. I propose that a reconstruction of the traditional Chinese idea of T'ien-jen-ho-i will help us envisage a new and salutary relation between humanity and nature.  相似文献   
15.
16.
Two cebus monkeys, with many years of experience matching a variety of static visual stimuli (forms and colors) within a standard matching-to-sample paradigm, were trained to press a left lever when a pair of displayed static stimuli were the same and to press a right lever when they were different. After learning the same/different task, the monkeys were tested for transfer to dynamic visual stimuli (flashing versus steady green disks), with which they had no previous experience. Both failed to transfer to the dynamic stimuli. A third monkey, also with massive past experience matching static visual stimuli, was tested for transfer to the dynamic stimuli within our standard matching paradigm, and it, too, failed. All 3 subjects were unable to reach a moderate acquisition criterion despite as many as 52 sessions of training with the dynamic stimuli. These results provide further evidence that, in monkeys, the matching (or identity) concept has a very limited reach; they consequently do not support the view held by some theorists that an abstract matching concept based on physical similarity is a general endowment of animals.  相似文献   
17.
Two studies using a computer-simulated, strategy-formulation game and business students were conducted using simultaneous verbal protocols. It was found that a number of information-processing and information-evaluation thought processes were significantly related to game performance. Consistent with what is known about individual decision making, the present results suggest that, for the task used in this study, individuals who engage in causal analysis perform better than those who do not. But those who focus on negative emotions, blindly repeat previously successful decisions, and engage in illogical through processes perform more poorly than those who do not. Causal replication using real managers within organizational settings, however, is needed before firm conclusions can be drawn from this research.  相似文献   
18.
Within the framework of valence-instrumentality (VI) theory, a fourfold model is developed to predict the contribution which is made by one outcome of an alternative to the valence of that alternative. The proposed model uses four subjective conditional probabilities which are based on the presence and absence of an alternative, and on the occurrence and nonoccurrence of an outcome. Valence is defined as the difference between the attractiveness values of the occurrence of an alternative (or an outcome) and the nonoccurrence of an alternative (or an outcome). Also, differences between subjective probabilities replace instrumentalities. Alternative valence-instrumentality formulations are analyzed in relation to the proposed fourfold model. The proposed model can be understood as a consistent application of Vroom's model (1964, Work and motivation, New York: Wiley), while other models are judged to be relatively deficient. The fourfold model, in combination with a matrix formulation of expectancy concepts, addresses a number of criticisms of VI theory and makes possible a test of the theory within the limits of its own assumptions.  相似文献   
19.
This research investigated the relationships between technology, interdependence, job characteristics, and employee satisfaction, performance, and influence. Technology was operationalized at the individual level of analysis to include the dimensions of input uncertainty, conversion uncertainty, and output uncertainty. Pooled, sequential, and reciprocal interdependence was assessed. The results indicated that input and conversion uncertainty and interdependence were strongly related to such job characteristics as autonomy, skill variety, task identity, task significance, and task feedback. While the job characteristics related positively to employee satisfaction, input and conversion uncertainty related negatively to satisfaction, thus creating a mutual suppression effect. Although the uncertainty dimensions did not relate significantly to performance, there is some evidence that this negative relationship was being suppressed by the positive relationship between job characteristics and performance. Both the job characteristics and the technology dimensions related positively to influence. Results were discussed in terms of appropriate matches between technology and job characteristics.  相似文献   
20.
Tapping rate and variability were measured as 73 normal, right-handed children in Grades 1–4 engaged in speeded unimanual finger tapping with and without concurrent recitation. Speaking reduced the rate of tapping and increased its variability to a greater extent in younger children than in older children. Developmental changes in variability but not rate were attributable to a greater number of lengthy (>500 ms) pauses in the tapping of younger children. Speaking slowed the right hand more than the left, and the degree of this asymmetry was constant across grade levels. The right-hand effect for tapping rate was not attributable to lengthy pauses. In contrast, asymmetric increases in tapping variability occurred only among children in Grade 1 and only when lengthy pauses were included in the data. The results implicate three mechanisms of intertask interference: one involving capacity limitations, a second involving cross-talk between motor control mechanisms for speech and finger movement, respectively, and a third factor involving occasional diversion of attention from tapping to speaking. These mechanisms are discussed in relation to developmental changes in mental capacity.  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