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   9487篇
  免费   126篇
  国内免费   9篇
教育   6610篇
科学研究   1141篇
各国文化   62篇
体育   643篇
综合类   3篇
文化理论   58篇
信息传播   1105篇
  2022年   63篇
  2021年   113篇
  2020年   166篇
  2019年   206篇
  2018年   337篇
  2017年   342篇
  2016年   312篇
  2015年   200篇
  2014年   322篇
  2013年   1596篇
  2012年   244篇
  2011年   269篇
  2010年   235篇
  2009年   210篇
  2008年   267篇
  2007年   218篇
  2006年   193篇
  2005年   180篇
  2004年   195篇
  2003年   141篇
  2002年   149篇
  2001年   212篇
  2000年   213篇
  1999年   192篇
  1998年   102篇
  1997年   139篇
  1996年   116篇
  1995年   87篇
  1994年   103篇
  1993年   74篇
  1992年   168篇
  1991年   131篇
  1990年   117篇
  1989年   147篇
  1988年   130篇
  1987年   105篇
  1986年   107篇
  1985年   114篇
  1984年   81篇
  1983年   95篇
  1982年   60篇
  1981年   73篇
  1980年   63篇
  1979年   104篇
  1978年   66篇
  1977年   64篇
  1976年   56篇
  1975年   50篇
  1974年   60篇
  1973年   56篇
排序方式: 共有9622条查询结果,搜索用时 31 毫秒
911.
Despite the importance of early writing development to children’s school success, research documents that early childhood teachers spend little time actively supporting children’s writing development in preschool classrooms. This article provides a framework for integrating writing experiences across the early childhood curriculum. Practical examples are given regarding how writing opportunities can be incorporated into existing activities and play settings. The metaphor of backgrounding and foregrounding writing experiences is used to illustrate ways that teachers can set writing rich environments and activities in a manner that makes it easier for teachers to bring these experiences into everyday learning opportunities. Attention is given to how teachers can bring writing to the foreground of the curriculum by drawing attention to writing materials, making natural connections with children’s interest and play, and scaffolding children’s early writing attempts and experiences.  相似文献   
912.
913.
914.
915.
916.
Alcohol-related posts on social-networking sites (SNS) can damage college students’ reputations and relationships and contribute to risky behavior. However, little is known about how college drinkers engage in privacy management involving alcohol content. Through 48 interviews and a Communication Privacy Management lens, this study uncovered criteria on which students relied to develop relatively impermeable boundaries around alcohol posts, the ways they collectively negotiated privacy with peers, and how participants implicitly and explicitly communicatively negotiated privacy turbulence. Findings suggest important connections between the co-occurrence of online privacy management and identity management, including how facework is involved in remediating privacy breaches and the co-opting of privacy. Findings also inform efforts to educate college drinkers about on-and-offline strategies to manage alcohol-related SNS content.  相似文献   
917.
Most of the fastest-growing string collections today are repetitive, that is, most of the constituent documents are similar to many others. As these collections keep growing, a key approach to handling them is to exploit their repetitiveness, which can reduce their space usage by orders of magnitude. We study the problem of indexing repetitive string collections in order to perform efficient document retrieval operations on them. Document retrieval problems are routinely solved by search engines on large natural language collections, but the techniques are less developed on generic string collections. The case of repetitive string collections is even less understood, and there are very few existing solutions. We develop two novel ideas, interleaved LCPs and precomputed document lists, that yield highly compressed indexes solving the problem of document listing (find all the documents where a string appears), top-k document retrieval (find the k documents where a string appears most often), and document counting (count the number of documents where a string appears). We also show that a classical data structure supporting the latter query becomes highly compressible on repetitive data. Finally, we show how the tools we developed can be combined to solve ranked conjunctive and disjunctive multi-term queries under the simple \({\textsf{tf}}{\textsf{-}}{\textsf{idf}}\) model of relevance. We thoroughly evaluate the resulting techniques in various real-life repetitiveness scenarios, and recommend the best choices for each case.  相似文献   
918.
To examine current practices in the use of psychoeducational evaluations for service delivery, we surveyed 91 service providers to college students with learning disabilities. The three purposes of the survey were to determine (a) whether service delivery decisions are based on information from psychoeducational evaluations, (b) which sections of the psychoeducational report are most useful in making service delivery decisions, and (c) the respondents' satisfaction with the tests and measurements for service delivery. The findings supported the common belief that data from psychoeducational evaluations serve as the primary basis for both eligibility and specific accommodation determinations. Respondents reported that all sections of the psychoeducational evaluation written report were useful, with the least useful section being test scores and the most useful being the summary of cognitive strengths and weaknesses. However, the section used most often for service delivery decisions was the professional's recommendations.  相似文献   
919.
In this paper, decomposition methods for multidimensional data hypercubes of OLAP systems are investigated. Criteria for reducing the computational complexity of the decomposition methods are presented and comparisons are made with the traditional solutions of multidimensional data analysis problems. Examples illustrating the application of these criteria to investigating the dynamics of computational complexity changes for specific types of reduction problems are considered.  相似文献   
920.
Mechanochemistry     
K L Sebastian 《Resonance》2007,12(5):48-59
Nano-sized molecular motors, which consume chemicals and do mechanical work are ubiquitous in nature. One of the most powerful such motors is the viral packaging motor, which consumes ATP and packages the viral DNA into the procapsid (the protein shell) of the virus. A pulling force applied to the loose end of the DNA can slow down the rate of packaging, thus showing that a mechanical force can slow down a chemical reaction. In this article we describe this packaging process and what is known about the mechanochemistry of the motor. K L Sebastian is a Professor in the Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore. His areas of interest is theoretical chemistry.  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