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   322篇
  免费   11篇
教育   217篇
科学研究   28篇
各国文化   10篇
体育   20篇
文化理论   8篇
信息传播   50篇
  2023年   2篇
  2022年   6篇
  2021年   4篇
  2020年   7篇
  2019年   7篇
  2018年   13篇
  2017年   11篇
  2016年   9篇
  2015年   11篇
  2014年   8篇
  2013年   55篇
  2012年   8篇
  2011年   12篇
  2010年   7篇
  2009年   6篇
  2008年   7篇
  2007年   3篇
  2006年   5篇
  2005年   5篇
  2004年   2篇
  2003年   4篇
  2002年   3篇
  2001年   3篇
  2000年   3篇
  1999年   9篇
  1998年   17篇
  1997年   3篇
  1996年   2篇
  1995年   15篇
  1994年   2篇
  1993年   3篇
  1992年   9篇
  1991年   8篇
  1990年   7篇
  1989年   6篇
  1988年   6篇
  1987年   5篇
  1986年   4篇
  1985年   2篇
  1984年   4篇
  1983年   3篇
  1982年   2篇
  1979年   3篇
  1976年   3篇
  1973年   2篇
  1924年   1篇
  1920年   1篇
  1867年   2篇
  1833年   2篇
  1830年   1篇
排序方式: 共有333条查询结果,搜索用时 0 毫秒
11.
12.
The Readers' Guide to Periodical Literature has been described as a cultural barometer. It supports scholars of history and culture by providing access to ideas circulated via the mass media in earlier times, but its own coverage and indexing practices also reveal attitudes and values toward issues of the time. The Progressive Era (1900–1924) coincides with the founding and growth of the Readers' Guide. Examining how the Readers' Guide directed readers' attention to matters of sexual and reproductive health in its first quarter century demonstrates changes in social attitudes and has implications for scholarly work. The array of index terms required to locate information on this topic indicates both barriers to information access for contemporary readers as well as challenges for present-day scholars concerned with recovering information of the era.  相似文献   
13.
Secondary data analysis was used to develop and examine disability-related differences in outcome constructs from the National Longitudinal Transition Study-2. Findings suggest that outcome constructs could be created that represented key elements of quality of life domains including social relationships, financial independence, financial supports, employment, emotional well-being, postsecondary education, independent living, health status, access to services, and advocating for needs. The constructs could be measured equivalently across disability groups, but young adults with high incidence disabilities, generally, experienced more positive outcomes than those with more severe disabilities, despite the finding that those with more severe disabilities have greater access to services and financial supports. Implications for future research and practice are discussed.  相似文献   
14.
An improvement on the transient response of tracking for the sampled-data system based on an improved PD-type iterative learning control (ILC) is proposed in this paper. The developed analog ILC method and the high-gain property tracker design methodology are first combined to significantly reduce learning epochs and overcome the initial condition shift problem and discontinuous reference input in the traditional ILC. Besides, the proposed ILC improves the transient response and decreases the rate of weighting matrices QQ to RR under the traditional linear quadratic tracker design. First, the off-line observer/Kalman filter identification (OKID) is used to determine the appropriate (low-) order system parameters and state estimator for the physical system with unknown system equation, so that the model-based PD-type ILC can be implemented for practical applications. Then, to improve the transient response and decrease the control effort, the proportional difference type (PD-type) ILC algorithm is combined with the high-gain property linear quadratic tracker (LQT) design to construct the high performance tracker for the model-based sampled-data systems. Furthermore, the discrete-time version high performance tracker design for the unknown stochastic sampled-data system via the iterative learning control method is proposed in this paper based on the Euler method and the digital redesign approach. Finally, some examples are given for illustrating the effectiveness of the proposed method.  相似文献   
15.
To further the understanding of the effects of early experiences, 9-month-old infants were observed during a frustration task. The analytical sample was composed of 348 linked triads of participants (adoptive parents, adopted child, and birth parent[s]) from a prospective adoption study. It was hypothesized that genetic risk for externalizing problems and affect dysregulation in the adoptive parents would independently and interactively predict a known precursor to externalizing problems: heightened infant attention to frustrating events. Results supported the moderation hypotheses involving adoptive mother affect dysregulation: Infants at genetic risk showed heightened attention to frustrating events only when the adoptive mother had higher levels of anxious and depressive symptoms. The Genotype × Environment interaction pattern held when substance use during pregnancy was considered.  相似文献   
16.
In Ireland and the UK it is accepted practice that agencies with formal responsibility for delivering school examinations allow examination candidates, and in many cases their teachers, to see their examination papers once they have been marked. Returned papers can carry various pieces of information; as well as the total score given for a performance, additional information is included in the form of the annotations left on the examination paper by the marking examiner. As far as we know there has been no research into how this information affects those who come into contact with it. The study uses teacher interview and survey data to explore whether a sociocultural approach to analysis can illuminate the factors that might influence their interpretation of those annotations. These analyses suggest that a key influence on the valid interpretation of an examiner's annotations is a teachers' involvement in examining activity. The analyses support further conceptualisation that these teacher-examiners' interpretative capacity is related to their positioning in a boundary zone between two different activity systems.  相似文献   
17.
Critics have argued that information and communication technologies (ICTs) disconnect people from their social networks and reduce public participation. Research in support of this perspective has been biased by two assumptions. The first is a tendency to privilege the Internet as a social system removed from the other ways people communicate. The second is a tendency to favor broadly supportive strong social ties. Survey and ethnographic observations from Netville, a 2-year community networking experiment, suggest that weak, not strong ties experience growth as a result of ICTs. By examining a unique and underexplored stage in the life cycle of a community networking project, the end of a networking trial, this article demonstrates how ICTs facilitate community participation and collective action (a) by creating large, dense networks of relatively weak social ties and (b) through the use of ICTs as an organizing tool.  相似文献   
18.
This paper compares and contrasts the use of AI principles in industrial training with more normal computer‐based training (CBT) approaches. A number of applications of CBT are illustrated (for example simulations, tutorial presentations, fault diagnosis, management games, industrial relations exercises) and compared with an alternative approach using AI. An evaluation of the relative merits of the two approaches will be given. Existing CBT packages are used to illustrate the points raised and the emphasis of the arguments will be on the effectiveness of AI and CBT in terms of both cost and learning. The position of AI applications within CBT is discussed, as is the task of getting started in applying these techniques.  相似文献   
19.
Intellectual performance is highly heritable and robustly predicts lifelong health and success but the earliest manifestations of genetic effects on this asset are not well understood. This study examined whether early executive function (EF) or verbal performance mediate genetic influences on subsequent intellectual performance, in 561 U.S.-based adoptees (57% male) and their birth and adoptive parents (70% and 92% White, 13% and 4% African American, 7% and 2% Latinx, respectively), administered measures in 2003–2017. Genetic influences on children's academic performance at 7 years were mediated by verbal performance at 4.5 years (β = .22, 95% CI [0.08, 0.35], p = .002) and not via EF, indicating that verbal performance is an early manifestation of genetic propensity for intellectual performance.  相似文献   
20.
The present study leveraged data from a longitudinal adoption study of 361 families recruited between 2003 and 2010 in the United States. We investigated how psychopathology symptoms in birth parents (BP; Mage = 24.1 years; 50.5–62.9% completed high school) and adoptive parents (AP; Mage = 37.8 years; 80.9% completed college; 94% mother–father couples) influenced children's behavioral inhibition (BI) trajectories. We used latent growth models of observed BI at 18 and 27 months, and 4.5 and 7 years in a sample of adopted children (Female = 42%, White = 57%, Black = 11%, Multi-racial = 21%, Latinx = 9%). BI generally decreased over time, yet there was substantial variability in these trajectories. Neither BP nor AP psychopathology symptoms independently predicted systematic differences in BI trajectories. Instead, we found that AP internalizing symptoms moderated the effects of BP psychopathology on trajectories of BI, indicating a gene by environment interaction.  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