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   225篇
  免费   2篇
  国内免费   2篇
教育   175篇
科学研究   23篇
各国文化   3篇
体育   11篇
文化理论   4篇
信息传播   13篇
  2023年   3篇
  2022年   4篇
  2021年   4篇
  2020年   5篇
  2019年   12篇
  2018年   16篇
  2017年   9篇
  2016年   12篇
  2015年   10篇
  2014年   13篇
  2013年   55篇
  2012年   4篇
  2011年   16篇
  2010年   3篇
  2009年   2篇
  2008年   8篇
  2007年   7篇
  2006年   3篇
  2005年   3篇
  2004年   6篇
  2003年   2篇
  2002年   1篇
  2001年   2篇
  2000年   1篇
  1999年   2篇
  1998年   5篇
  1996年   3篇
  1995年   2篇
  1992年   2篇
  1990年   1篇
  1987年   1篇
  1984年   1篇
  1980年   1篇
  1979年   1篇
  1975年   1篇
  1971年   1篇
  1967年   1篇
  1964年   1篇
  1963年   1篇
  1961年   1篇
  1923年   1篇
  1915年   1篇
  1912年   1篇
排序方式: 共有229条查询结果,搜索用时 15 毫秒
131.
The exposure of historic stone to processes of lichen-induced surface biomodification is determined, first and foremost, by the bioreceptivity of those surfaces to lichen colonization. As an important component of surface bioreceptivity, spatiotemporal variation in stone surface temperature plays a critical role in the spatial distribution of saxicolous lichen on historic stone structures, especially within seasonally hot environments. The ornate limestone and tufa stairwell of the Monastery of Cartuja (1516), Granada, Spain, exhibits significant aspect-related differences in lichen distribution. Lichen coverage and diurnal fluctuations in stone surface temperature on the stairwell were monitored and mapped, under anticyclonic conditions in summer and winter, using an infrared thermometer and Geographical Information Systems approach. This research suggests that it is not extreme high surface temperatures that determine the presence or absence of lichen coverage on stonework. Instead, average stone surface temperatures over the course of the year seem to play a critical role in determining whether or not surfaces are receptive to lichen colonization and subsequent biomodification. It is inferred that lichen, capable of surviving extreme surface temperatures during the Mediterranean summer in an ametabolic state, require a respite period of lower temperatures within which they can metabolize, grow and reproduce. The higher the average annual temperature a surface experiences, the shorter the respite period for any lichen potentially inhabiting that surface. A critical average temperature threshold of approximately 21 °C has been identified on the stairwell, with average stone surface temperatures greater than this generally inhibiting lichen colonization. A brief visual condition assessment between lichen-covered and lichen-free surfaces on the limestone sections of the stairwell suggests relative bioprotection induced by lichen coverage, with stonework quality and sharpness remaining more defined beneath lichen-covered surfaces. The methodology employed in this paper may have further applications in the monitoring and mapping of thermal stress fatigue on historic building materials.  相似文献   
132.
Resilience is an interactive process involving internal skills that should be promoted, especially in the early stages of development. This study aims to adapt and implement two themes from the European Curriculum for Resilience Promotion – RESCUR, namely, ‘Developing Communication Skills’ and ‘Establishing and Maintaining Healthy Relationships’, for deaf and hard-of-hearing (DHH) students. The study included 37 children and adolescents from three Portuguese regions and its impact was evaluated through the perspectives of the students, their guardians and their teachers. Each 90-minute session was implemented weekly. The sessions followed the RESCUR curriculum structure with necessary adaptations to the mindfulness activities, stories, role-play and worksheets. The mean scores increased from pre- to post-intervention assessment on all instruments, namely, KIDSCREEN-10 (children/adolescents), KIDSCREEN-10 (guardians) and CYRM-28 (teachers). The implementation of adapted curricula promoting resilience seems to be beneficial to DHH children, allowing the development of specific resilience-associated skills, and thus enhancing health, well-being and quality of life.  相似文献   
133.
This study examines the effect of R&D tax credits on innovation activities of Canadian manufacturing firms. Over the 1997-1999 period the Federal and Provincial R&D tax credit programs were used by more than one third of all manufacturing firms and by close to two thirds of firms in high-technology sectors. We investigate the average effect of R&D tax credits on a series of innovation indicators such as: number of new products, sales with new products, originality of innovation, etc. using a non-parametric matching approach. Compared to a hypothetical situation in the absence of R&D tax credits, recipients of tax credits show significantly better scores on most but not all performance indicators. We therefore conclude that tax credits lead to additional innovation output.  相似文献   
134.
Ultrasound is being investigated as a trigger mechanism to deliver high concentrations of chemotherapy drugs to cancerous tissues using polymeric micelles. In this paper, we examined the kinetics of acoustic release of doxorubicin using stabilized and non-stabilized micelles. Kinetic models were used to regress release and re-encapsulation time constants for three different compounds, namely non-stabilized Pluronic® P105 micelles, P105 micelles stabilized using an interpenetrating network of N,N-diethylacrylamide and micelles formed by PEO-b-poly(NIPAAm-co-HEMA-lactaten). Results showed that the kinetic release constant (kr) depends on the micellar system under investigation. On the other hand, there is no statistically significant difference between re-encapsulation rate constants for stabilized and unstabilized micelles. We hypothesize that kr depends on the degree of cross-linking or stabilization.  相似文献   
135.
In the recent years, several libraries in the United States have been experimenting with Book Industry Standards and Communications (BISAC), the classification system of the book industry, as an alternative to the Dewey Decimal Classification. Although rarely discussed, these cases of implementation of BISAC arguably resemble other past cases of replacement of traditional classifications that received the name of reader-interest classifications. In this article, a comparison of the BISAC cases to the previous cases of reader-interest classifications is taken in order to determine if the current application of BISAC to libraries is susceptible to the same problems, dangers, and ends as occurred in the past.  相似文献   
136.
ABSTRACT

The purpose of this study was to investigate the impact of older volunteers’ available human, social, and cultural capital on their motivational forces to volunteer, measured through the Volunteer Function Inventory. A large European database of 955 older volunteers (i.e., aged 50+) was employed, and Seemingly Unrelated Regressions showed that older volunteers have different motivations according to different sets of individual resources. Furthermore, lower amounts of human and social capital (e.g., low educational level, poor health, being widowed, divorced or single) are associated with a higher propensity to volunteer to enhance one’s own self-esteem, to avoid thinking of personal problems, and for social reasons. These results have important implications for policy makers and voluntary organizations if they want to enhance volunteering among older people with less resources, i.e., that are more at risk of social exclusion. For example, according to the results of this study, policy makers could consider developing more tailored opportunities for involving older volunteers with low educational level, poor health, widowed, divorced, or single. They could do this by underlying that volunteering offers possibilities to satisfy motivational needs important to the, elderly, e.g., to increase self-esteem, to deal with personal problems in a better way, and to have satisfying social contacts.  相似文献   
137.
This paper analyzes the impact of a reminiscence program on the psychological well-being and ego integrity of elderly people with depressive symptomatology. Ninety people aged 65 and over participated in a quasi-experimental design with pretest and posttest evaluations. They were assigned to one of three groups: (a) experimental group (reminiscence sessions); (b) control group or (c) control-placebo group (weekly relaxation sessions). The results indicate that only the experimental group had significant increases in its overall psychological well-being and ego integrity. This suggests that the promotion of instrumental and integrative reminiscences is an important therapeutic tool for psychological well-being in elderly people with depressive symptomatology.  相似文献   
138.
Teachers are a critical mass of professionals whose growth within the teaching profession is of great consequence to the effective imparting of knowledge and skills to students. While previous studies maintain that superior subject matter mastery, the ability to relate well to students, and innovative teaching strategies are qualities inherent in the teacher that qualify them to be adjudged as expert teachers, the present qualitative study argues that teachers’ life in the academe, their choice of Self-enhancement schemes, their self-view and their conception of the schoolwork environment are contributory building blocks in defining and maintaining their expertise.  相似文献   
139.
140.
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