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   2400篇
  免费   45篇
  国内免费   29篇
教育   1706篇
科学研究   290篇
各国文化   21篇
体育   153篇
综合类   71篇
文化理论   19篇
信息传播   214篇
  2023年   12篇
  2022年   38篇
  2021年   61篇
  2020年   71篇
  2019年   64篇
  2018年   84篇
  2017年   100篇
  2016年   79篇
  2015年   91篇
  2014年   128篇
  2013年   390篇
  2012年   123篇
  2011年   135篇
  2010年   111篇
  2009年   102篇
  2008年   105篇
  2007年   96篇
  2006年   90篇
  2005年   69篇
  2004年   72篇
  2003年   49篇
  2002年   50篇
  2001年   34篇
  2000年   37篇
  1999年   22篇
  1998年   25篇
  1997年   17篇
  1996年   15篇
  1995年   13篇
  1994年   13篇
  1993年   5篇
  1992年   5篇
  1991年   15篇
  1990年   11篇
  1989年   8篇
  1988年   10篇
  1987年   7篇
  1986年   5篇
  1985年   14篇
  1984年   10篇
  1983年   4篇
  1982年   7篇
  1981年   9篇
  1979年   4篇
  1978年   4篇
  1976年   4篇
  1972年   4篇
  1885年   3篇
  1882年   6篇
  1880年   5篇
排序方式: 共有2474条查询结果,搜索用时 15 毫秒
61.
北京耕地流失的时空特征与驱动机制   总被引:14,自引:0,他引:14  
孙强  蔡运龙  王乐 《资源科学》2007,29(4):158-163
利用1996年和2004年北京市两期土地利用图,提取各类用地的图斑,运用GIS技术和数理统计方法,分析了1996年~2004年间北京耕地流失的特点及其影响因素。结果发现:1996年~2004年北京土地利用变化中,大多数地类转换都与耕地直接有关,耕地流失是北京土地利用变化的核心问题;城镇扩展主要占用耕地,且耕地生产力高的平原地区因建设占用而流失的耕地量大;远郊山区耕地被建设占用的压力相对较小,但被生态用地占用的压力相对较大;1996年~2004年间,尽管耕地面积减少,但耕地破碎化程度却在加重;地形和交通状况对耕地的空间变化过程影响显著。本文研究表明,第三产业的快速发展是促使北京地区耕地流失的最主要的动力, 由此带来的居民生活水平提高对北京耕地变化的解释力最强,恰好与前人相关研究结论相互印证;人口快速增长、区域土地市场过度竞争、农业结构调整及退耕还林政策也是北京耕地流失的重要驱动因素。  相似文献   
62.
Factor analysis of the Swedish version of the Wechsler Adult Intelligence Scale-Revised (WAIS-R) on a group of 88 adult individuals with dyslexia showed a three-factor structure with a verbal comprehension (VC) factor, a perceptual organization (PO) factor, and a freedom from distractibility (FD) factor. The results of this factor analysis support earlier findings from factor analyses of adults in the original U.S. normative sample and in different clinical groups. The profile of scores for the sample of individuals with dyslexia showed the expected pattern, with PO highest and FD lowest. The predicted pattern was also observed using Bannatyne's recategorization of WAIS-R subtests. As has been true for other typical and exceptional samples, women scored significantly higher than men on the Digit Symbol subtest. Related to this gender difference, Digit Symbol scores proved to be sensitive to problems associated with dyslexia only for men with dyslexia. Also, education level was shown to be related to verbal (V)-performance (P) IQ discrepancy, with larger P > V differences observed for participants with fewer years of formal schooling. Regardless of these gender and education differences, the characteristic factor score and Bannatyne patterns were identified for both men and women and for three different subsamples categorized by educational level.  相似文献   
63.
分形及分形艺术的研究方兴未艾。通过结合现代包装工业的切实需求,阐述将分形艺术及理论用于包装设计和包装防伪的思想,并提出可供实施的方法,分析其广阔的应用前景。  相似文献   
64.
An important purpose of internships in teacher preparation programmes is to develop competence through experience. The research questions in the present study concern student teachers’ interpersonal profiles (i.e. patterns of their interpersonal behaviour as perceived by students) and the accuracy of their self-belief regarding the interpersonal relationship with students at the beginning and end of the internship. Participants were student teachers (n=34) of a one-year teacher education programme. There were fewer student teachers with preferable interpersonal profiles at the end of the internship than in the beginning. Self-beliefs at the beginning indicated that the majority of student teachers were underestimating themselves; at the end of the internship most of them were overestimating themselves. About two-thirds had more accurate self-beliefs at the end of the internship than at the beginning. Overestimating oneself seemed negatively related to more accurate self-beliefs at the end of the internship and student teachers with more preferable profiles had more accurate self-beliefs.  相似文献   
65.
Abstract

Recent significant changes in technology such as Artificial Intelligence (AI) and big data analysis have a wide impact in many areas of human societies, not least in education. Advances in efficiency of new technologies, with impacts in renewable energy and transport affected by environmental concerns and climate change mitigation, demand a reassessment and adjustment of the industrial structure of the economy. Technological advances enhancing creativity and analytical skills mean people must learn and adapt to a fast-changing economic environment. This paper present some key changes in Australian educational areas in recent years that are important and relevant to the subject of education innovation and philosophy to achieve outcomes in training and sustainable economic development, as anticipated by the community and government. Education courses and curricula in many countries have been transformed by technological advance. It is the swift incorporation of new technologies that best prepares students for the dynamics of economic and social change. Even though technological responsiveness is not a new phenomenon, it is established that the teaching methods found to be most successful include complementary and supplemental courses producing multi-skilled and creative graduates. These courses are delivered with significant emphasis upon self-development skills and are less focused upon traditional content. A move toward horizontal focus and a student-centric balance is the current trend, displacing vertical over-specialisation of learning. Yet, the central role of educator is seen as still appropriate and necessary where the aim is to equip graduates with creative and adaptive skills.  相似文献   
66.
ABSTRACT

Along with the dramatic expansion of private tutoring around the world, a significant body of literature has been produced to understand this phenomenon. While many studies consider the issue of geographic location, the spatial dimension tends not to be a central focus of private tutoring studies. In contrast, the present essay applies mobility theory to research from Cambodia, where private tutoring is essential to student success. It does so in order to place private tutoring provision into a broader perspective that includes but moves beyond the economic dimensions of supply and demand and the sociological dimensions of economic, cultural, and social capital to include consideration of how private tutoring provision is constrained by a multidimensional spatial field of possibilities and how private tutoring participation is enabled by one’s position and abilities in relation to that field. The paper argues for increased attention to ‘spatial capital’ in studies of private tutoring and education generally.  相似文献   
67.
为克服因显示屏、视觉等因素造成的阅读不便,满足用户听资讯的需求,结合语音合成技术,提出基于Android平台的资讯播报软件。软件在服务器端通过RSS及其相关技术实现自动采集资讯,手机客户端运用API以及科大讯飞提供的语音SDK实现了频道订阅与资讯播报,通过HTTP协议实现手机端能即时获得订阅频道的最新资讯。实验结果表明,软件满足用户轻松愉快的阅读需求,同时具备高自然度的语音播报功能。  相似文献   
68.
对于高职院校的学生来说,英语应用文信函的写作是英语综合能力的重要组成部分,也是高等学校英语应用能力考试的基本要求之一。本文结合当前高职学生英语应用文信函写作的现状和实际存在的问题,提出了"三段式"写作策略并进行了详细的阐述分析,以帮助学生提高英语应用文信函的写作水平。  相似文献   
69.
湿地是人类社会存在和发展不可或缺的重要资源,是人类赖以生存的重要物质基础,其开发、利用、保护已经引起世界各国的普遍重视。从我国湿地保护管理的现状来看,湿地保护与合理利用在我国还仅处于起步阶段,存在着很多的问题。本文在分析了我国湿地保护利用中存在的问题,借鉴国外相关经验,提出了有效的解决措施。  相似文献   
70.
The earliest ovules in the Late Devonian (Famennian) are surrounded by a cupule that is involved in both protection and pollination, and generally have free integumentary lobes. Here we report a new taxon from the Famennian of China, Guazia dongzhiensis gen. et sp. nov. The terminally borne ovule is apparently acupulate (without cupule) and has four radially arranged wing-like integumentary lobes that are extensively fused, and folded lengthwise and inwards. Guazia provides evidence that not all Devonian seeds possess a cupule and it increases their diversity in integumentary lobes. This genus also suggests that the integuments develop new functions, probably including wind dispersal at the expense of the cupules.  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