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   1279篇
  免费   11篇
  国内免费   2篇
教育   868篇
科学研究   147篇
各国文化   23篇
体育   85篇
综合类   1篇
文化理论   33篇
信息传播   135篇
  2019年   22篇
  2018年   34篇
  2017年   29篇
  2016年   21篇
  2015年   19篇
  2014年   20篇
  2013年   356篇
  2012年   17篇
  2011年   32篇
  2010年   16篇
  2009年   24篇
  2008年   27篇
  2007年   27篇
  2006年   16篇
  2005年   16篇
  2004年   23篇
  2003年   14篇
  2002年   15篇
  2001年   18篇
  2000年   12篇
  1999年   16篇
  1998年   11篇
  1997年   11篇
  1996年   14篇
  1995年   18篇
  1994年   17篇
  1993年   22篇
  1992年   18篇
  1991年   13篇
  1990年   15篇
  1989年   9篇
  1988年   10篇
  1987年   16篇
  1986年   18篇
  1985年   12篇
  1984年   12篇
  1983年   12篇
  1982年   13篇
  1981年   11篇
  1980年   14篇
  1979年   16篇
  1978年   14篇
  1977年   17篇
  1976年   16篇
  1975年   10篇
  1974年   15篇
  1973年   11篇
  1970年   8篇
  1966年   9篇
  1920年   8篇
排序方式: 共有1292条查询结果,搜索用时 0 毫秒
71.
The early identification of young children's special educational needs (SEN), as well as the development of specific strategies to support those children identified with special needs, are increasingly recognised as crucial to facilitating good adjustment to school and to ensuring that such children are helped to reach their full potential in education. Using a large national sample of young children in England whose developmental progress was followed up from pre‐school, this study investigates which child, family, home and pre‐school factors can be viewed as risk or protective factors for later SEN‐status at age 10. The experience of high‐quality pre‐school education is shown to reduce the likelihood of a child being identified as experiencing SEN in the long run. Teachers’ assessments of SEN are found to be strongly related to children's reading and mathematics attainment, but other factors also predict SEN, including a child's age within a year group.  相似文献   
72.
There is increasing enthusiasm for teaching approaches that combine mathematics and biology. The call for integrating more quantitative work in biology education has led to new teaching tools that improve quantitative skills. Little is known, however, about whether increasing interdisciplinary work can lead to adverse effects, such as the development of broader but shallower skills or the possibility that math anxiety causes some students to disengage in the classroom, or, paradoxically, to focus so much on the mathematics that they lose sight of its application for the biological concepts in the center of the unit at hand. We have developed and assessed an integrative learning module and found disciplinary learning gains to be equally strong in first-year students who actively engaged in embedded quantitative calculations as in those students who were merely presented with quantitative data in the context of interpreting biological and biostatistical results. When presented to advanced biology students, our quantitative learning tool increased test performance significantly. We conclude from our study that the addition of mathematical calculations to the first year and advanced biology curricula did not hinder overall student learning, and may increase disciplinary learning and data interpretation skills in advanced students.  相似文献   
73.
As new media technologies and platforms emerge and take hold in our society, traditional publishers are wondering: What’s in this new content climate for me? The simple answer is: a lot. The digital world, mobile content delivery mechanisms and the public’s increasing comfort—even preference for—a media menu from which they can pick and choose what they want and how they want to receive it, brings exciting and potentially lucrative opportunities. For publishers who understand how to leverage their brand and create authentic, identifiable value in the eyes of the customer, risk can be reduced and new revenue streams built. Here are four best practices to position your publishing company for growth.  相似文献   
74.
The successful encapsulation of human hepatocellular carcinoma (HepG2) cells would greatly assist a broad range of applications in tissue engineering. Due to the harsh conditions during standard chitosan fiber fabrication processes, encapsulation of HepG2 cells in chitosan fibers has been challenging. Here, we describe the successful wet-spinning of chitosan-alginate fibers using a coaxial flow microfluidic chip. We determined the optimal mixing conditions for generating chitosan-alginate fibers, including a 1:5 ratio of 2% (w∕w) water-soluble chitosan (WSC) solution to 2% (w∕w) alginate solution. Ratio including higher than 2% (w∕w) WSC solution increased aggregation throughout the mixture. By suspending cells in the WSC-alginate solution, we successfully fabricated HepG2 cell-laden fibers. The encapsulated HepG2 cells in the chitosan-alginate fibers were more viable than cells encapsulated in pure alginate fibers, suggesting that cross-linked chitosan provides a better environment for HepG2 cells than alginate alone. In addition, we found that the adhesion of HepG2 cells on the chitosan-alginate fiber is much better than that on the alginate fibers.  相似文献   
75.
76.

In two dimensions (2D), representations associated with slopes are seen in numerous forms before representations associated with derivatives are presented. These include the slope between two points and the constant slope of a linear function of a single variable. In almost all multivariable calculus textbooks, however, the first discussion of slopes in three dimensions (3D) is seen with the introduction of partial derivatives. The nature of the discussions indicates that authors seem to assume that students are able to naturally extend the concept of a 2D slope to 3D and correspondingly it is not necessary to explicitly present slopes in 3D. This article presents results comparing students that do not explicitly discuss slopes in 3D with students that explicitly discuss slopes in 3D as a precursor to discussing derivatives in 3D. The results indicate that students may, in fact, have significant difficulty extending the concept of a 2D slope to a 3D slope. And that the explicit presentation of slopes in 3D as a precursor to the presentation of derivatives in 3D may significantly improve student comprehension of topics of differentiation in multivariable calculus.

  相似文献   
77.
Genetics instruction in introductory biology is often confined to Mendelian genetics and avoids the complexities of variation in quantitative traits. Given the driving question “What determines variation in phenotype (Pv)? (Pv=Genotypic variation Gv + environmental variation Ev),” we developed a 4-wk unit for an inquiry-based laboratory course focused on the inheritance and expression of a quantitative trait in varying environments. We utilized Brassica rapa Fast Plants as a model organism to study variation in the phenotype anthocyanin pigment intensity. As an initial curriculum assessment, we used free word association to examine students’ cognitive structures before and after the unit and explanations in students’ final research posters with particular focus on variation (Pv = Gv + Ev). Comparison of pre- and postunit word frequency revealed a shift in words and a pattern of co-occurring concepts indicative of change in cognitive structure, with particular focus on “variation” as a proposed threshold concept and primary goal for students’ explanations. Given review of 53 posters, we found ∼50% of students capable of intermediate to high-level explanations combining both Gv and Ev influence on expression of anthocyanin intensity (Pv). While far from “plug and play,” this conceptually rich, inquiry-based unit holds promise for effective integration of quantitative and Mendelian genetics.  相似文献   
78.
79.
80.
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