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   19558篇
  免费   1858篇
  国内免费   1343篇
  2023年   274篇
  2022年   257篇
  2021年   363篇
  2020年   650篇
  2019年   730篇
  2018年   686篇
  2017年   801篇
  2016年   766篇
  2015年   528篇
  2014年   645篇
  2013年   2187篇
  2012年   445篇
  2011年   544篇
  2010年   480篇
  2009年   669篇
  2008年   864篇
  2007年   944篇
  2006年   900篇
  2005年   804篇
  2004年   680篇
  2003年   584篇
  2002年   528篇
  2001年   330篇
  2000年   330篇
  1999年   269篇
  1998年   211篇
  1997年   183篇
  1996年   162篇
  1995年   137篇
  1994年   129篇
  1993年   105篇
  1992年   98篇
  1991年   57篇
  1990年   61篇
  1989年   44篇
  1988年   53篇
  1987年   39篇
  1985年   419篇
  1984年   460篇
  1983年   370篇
  1982年   475篇
  1981年   464篇
  1980年   468篇
  1979年   414篇
  1978年   476篇
  1977年   395篇
  1976年   390篇
  1975年   295篇
  1974年   282篇
  1973年   244篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
The country‐of‐origin effect is a topic central to the field of international marketing. Country of origin has been found to exert a particularly potent effect on consumer evaluation in situations where there is a strong link between a country and a particular product category. The present study provides further insight into how this particular effect can be understood. Drawing on a novel conceptualization of how country image and product categories interact, this study tested the relative evaluative relevance of product category with respect to estimates of brand equity across a variety of product categories. The findings suggest that facets of a country's image that are more closely related to the evaluation situation exert a greater influence on the evaluation of brands. This result encourages scholars as well as practitioners to re‐evaluate which situations might cause the country of origin effect to hold managerial relevance and paves the way for new paths toward a more comprehensive understanding of the effect. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
13.
Gábor L. Ambrus 《Zygon》2020,55(4):875-897
We are easily misguided as to the true nature of Facebook, and tend to treat it simply as a powerful technological instrument in the service of human intentions. We can, however, gain a better picture of it through recourse to the Jewish tradition of the golem, an image of human beings, created by them in a re-enactment of their own creation by God. It turns into a magic servant in modernity with an inherent dynamic running between its human and its subhuman characteristics. This dynamic is the main cause behind its becoming uncontrollable. In like manner, what is subhuman in Facebook serves its masters and functions under their total control, but also empowers Facebook's increasingly human operation, an algorithm-based capability which raises growing doubts about what counts as human. Facebook implies the crisis of humanity which coincides with the “death of God,” that is, the obsolescence of the idea of a divine creator.  相似文献   
14.
This paper investigates the salience of social-psychological factors in explaining why drivers purchase (or fail to purchase) New Energy Vehicles (NEVs)—including hybrid electric vehicles, battery electric vehicles, and fuel cell electric vehicles—in China. A questionnaire measuring six dimensions (including attitudes, subjective norms, perceived behavioral control, personal norms, low-carbon awareness and policy) was distributed in Tianjin, where aggressive policy incentives for NEVs exist yet adoption rates remain low. Correlation analysis and hierarchical multiple regression analyses are applied data collected through 811 valid questionnaires. We present three main findings. First, there is an “awareness-behavior gap” whereby low-carbon awareness has a slight moderating effect on purchasing behavior via psychological factors. Second, subjective norms has a stronger influence on intention to purchase New Energy Vehicles than other social-psychological factors. Third, acceptability of government policies has positive significant impact on adoption of New Energy Vehicles, which can provide reference potential template for other countries whose market for New Energy Vehicles is also in an early stage.  相似文献   
15.
We examined the functional role of verbalizations in the generalization of self-instructional training with preschoolers. Children learned to overtly self-instruct during classroom work periods prior to covert training. Data were collected on children's acquisition of verbal regulation during training and on overt use of self-instructions in the classroom generalization setting. Results of a multiple baseline design across subjects indicated that treatment effects were evident in the training setting but did not generalize to the classroom until children were emitting overt self-instructions in the classroom itself. The production of self-verbalizations in the generalization setting was related to changes in correct responding, on-task behavior, and efficiency in completing academic work.  相似文献   
16.
17.
This study compared the effectiveness of a videotape training program with other methods of teaching children self-protection to prevent child abduction. Subjects were kindergarten and first-grade students. Four experimental conditions were presented: videotape with behavior rehearsal, videotape only, a standard safety program, and no training. Acquisition of self-protective behaviors was measured at posttraining and follow-up by having confederate adults entice the children near their schools and homes. Results revealed that the videotape program with behavior rehearsal was highly effective in teaching children safe responses to potential abductors. The standard safety program was effective with fewer than half of the children. Three fourths of the children who received no training immediately agreed to go with the confederate suspects. The videotape program can be easily used with groups of young children in a classroom setting.  相似文献   
18.
In a series of conditions, pigeons chose between 1.5 s and 3 s of access to grain, each preceded by some delay. The delay that preceded the small reinforcer was constant throughout a condition. The delay that preceded the large reinforcer was increased or decreased a number of times each session in order to estimate an "indifference point," a delay at which the subject chose each alternative about equally often. The experiment was designed to determine whether variations in any of four features of this adjusting-delay procedure would systematically alter the estimated indifference points. The four features were the total trial duration, the number of center-key responses necessary to begin a trial, the number of choice trials that preceded each change in the adjusting delay, and step size--the size of each increment and decrement in the delay. Manipulation of the first three features had no systematic effects on the indifference points. As step size was increased from 0.5 s to 6 s, within-session variability of the adjusting delay steadily increased, and the 6-s step size produced larger indifference-point estimates for some subjects. The results suggest that, within certain limits, these procedural features can be altered without affecting the indifference-point estimates, but that the use of a large step size can distort the estimates. Some theoretical implications of the relative constancy of indifference points across these procedural variations are discussed.  相似文献   
19.
Three severely mentally retarded adolescents were studied under discrete-trial procedures in which a choice was arranged between edible reinforcers that differed in magnitude and, in some conditions, delay. In the absence of delays the larger reinforcer was consistently chosen. Under conditions in which the smaller reinforcer was not delayed, increasing the delay to delivery of the larger reinforcer decreased the percentage of trials in which that reinforcer was chosen. All subjects directed the majority of choice responses to the smaller reinforcer when the larger reinforcer was sufficiently delayed, although the value at which this occurred differed across subjects. Under conditions in which the larger reinforcer initially was sufficiently delayed to result in preference for the smaller one, progressively increasing in 5-s increments the delay to both reinforcers increased percentage of trials with the larger reinforcer chosen. At sufficiently long delays, 2 of the subjects consistently chose the larger, but more delayed, reinforcer, and the 3rd subject chose that reinforcer on half of the trials. These results are consistent with the findings of prior studies in which adult humans responded to terminate noise and pigeons responded to produce food.  相似文献   
20.
In two experiments, key-peck responding of pigeons was compared under variable-interval schedules that arranged immediate reinforcement and ones that arranged unsignaled delays of reinforcement. Responses during the nominal unsignaled delay periods had no effect on the reinforcer presentations. In Experiment 1, the unsignaled delays were studied using variable-interval schedules as baselines. Relative to the immediate reinforcement condition, 0.5-s unsignaled delays decreased the duration of the reinforced interresponse times and increased the overall frequency of short (<0.5-s) interresponse times. Longer, 5.0-s unsignaled delays increased the duration of the reinforced interresponse times and decreased the overall frequency of the short interresponse times. In Experiment 2, similar effects to those of Experiment 1 were obtained when the 0.5-s unsignaled delays were imposed upon a baseline schedule that explicitly arranged reinforcement of short interresponse times and therefore already generated a large number of short interresponse times. The results support earlier suggestions that the unsignaled 0.5-s delays change the functional response unit from a single key peck to a multiple key-peck unit. These findings are discussed in terms of the mechanisms by which contingencies control response structure in the absence of specific structural requirements.  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