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   9684篇
  免费   290篇
  国内免费   346篇
教育   4896篇
科学研究   2537篇
各国文化   10篇
体育   192篇
综合类   429篇
文化理论   14篇
信息传播   2242篇
  2024年   4篇
  2023年   109篇
  2022年   264篇
  2021年   467篇
  2020年   538篇
  2019年   469篇
  2018年   292篇
  2017年   330篇
  2016年   367篇
  2015年   425篇
  2014年   760篇
  2013年   722篇
  2012年   697篇
  2011年   667篇
  2010年   430篇
  2009年   442篇
  2008年   470篇
  2007年   539篇
  2006年   535篇
  2005年   454篇
  2004年   379篇
  2003年   326篇
  2002年   207篇
  2001年   141篇
  2000年   88篇
  1999年   52篇
  1998年   30篇
  1997年   28篇
  1996年   20篇
  1995年   11篇
  1994年   13篇
  1993年   3篇
  1992年   10篇
  1991年   6篇
  1990年   6篇
  1989年   5篇
  1985年   3篇
  1976年   1篇
  1957年   10篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
丁文姚  李健  韩毅 《图书情报工作》2019,63(22):118-128
[目的/意义] 探索期刊论文科学数据引用特征与规律不仅有助于描述学科领域对科学数据的利用情况,还能够揭示学术成果表达中的数据引用模式。[方法/过程] 以我国图书情报领域6种期刊2017年与2018年第一期刊载论文为样本,结合国家标准《信息技术科学数据引用》的引用元素,采用内容分析法从9个维度对样本论文的科学数据引用行为进行数据编码,应用统计学方法描述图书情报领域期刊论文科学数据引用特征并探索不同维度特征间的关联关系。[结果/结论] 图书情报领域期刊论文广泛引用来自国内外的统计整理类科学数据,对期刊论文中个人研究科学数据的引用量较大;科学数据引用标注方式与科学数据类型存在一定对应关系,但多样化的标注方式缺乏统一性;二手引用现象较为突出,二手引用程度与科学数据创建者类型相关。  相似文献   
42.
Aspect mining, which aims to extract ad hoc aspects from online reviews and predict rating or opinion on each aspect, can satisfy the personalized needs for evaluation of specific aspect on product quality. Recently, with the increase of related research, how to effectively integrate rating and review information has become the key issue for addressing this problem. Considering that matrix factorization is an effective tool for rating prediction and topic modeling is widely used for review processing, it is a natural idea to combine matrix factorization and topic modeling for aspect mining (or called aspect rating prediction). However, this idea faces several challenges on how to address suitable sharing factors, scale mismatch, and dependency relation of rating and review information. In this paper, we propose a novel model to effectively integrate Matrix factorization and Topic modeling for Aspect rating prediction (MaToAsp). To overcome the above challenges and ensure the performance, MaToAsp employs items as the sharing factors to combine matrix factorization and topic modeling, and introduces an interpretive preference probability to eliminate scale mismatch. In the hybrid model, we establish a dependency relation from ratings to sentiment terms in phrases. The experiments on two real datasets including Chinese Dianping and English Tripadvisor prove that MaToAsp not only obtains reasonable aspect identification but also achieves the best aspect rating prediction performance, compared to recent representative baselines.  相似文献   
43.
In recent years, strategies focused on data-driven innovation (DDI) have led to the emergence and development of new products and business models in the digital market. However, these advances have given rise to the development of sophisticated strategies for data management, predicting user behavior, or analyzing their actions. Accordingly, the large-scale analysis of user-generated data (UGD) has led to the emergence of user privacy concerns about how companies manage user data. Although there are some studies on data security, privacy protection, and data-driven strategies, a systematic review on the subject that would focus on both UGD and DDI as main concepts is lacking. Therefore, the present study aims to provide a comprehensive understanding of the main challenges related to user privacy that affect DDI. The methodology used in the present study unfolds in the following three phases; (i) a systematic literature review (SLR); (ii) in-depth interviews framed in the perspectives of UGD and DDI on user privacy concerns, and finally, (iii) topic-modeling using a Latent Dirichlet allocation (LDA) model to extract insights related to the object of study. Based on the results, we identify 14 topics related to the study of DDI and UGD strategies. In addition, 14 future research questions and 7 research propositions are presented that should be consider for the study of UGD, DDI and user privacy in digital markets. The paper concludes with an important discussion regarding the role of user privacy in DDI in digital markets.  相似文献   
44.
Firms are increasingly relying on business insights obtained by deploying data analytics. Analytics-driven business decisions have thus taken a strategic imperative role for the competitive advantage of a firm to endure. The extent and effectiveness through which business firms can actually derive benefits by deploying big data-based practices requires deep analysis and calls for extensive research. This study extends the big data analytics capability (BDAC) model by examining the mediatory effects of organizational culture (CL) between internal analytical knowledge (KN) and BDAC, as well as the mediating effects of BDAC between CL and firm performance. The findings bring into focus that CL plays the role of complementary mediation between BDAC and KN to positively impact firm performance (FP); BDAC also plays a similar mediatory role between CL and the performance of a firm.  相似文献   
45.
ABSTRACT

This study aimed to assess which combination of subjective and empirical data might help to identify the expertise level. A group of 10 expert coaches classified 40 participants in 5 different expertise groups based on the video footage of the rallies. The expertise levels were determined using a typology based on a continuum of 5 conative stages: (1) structural, (2) functional, (3) technical, (4) contextual, and (5) expertise. The video allowed empirical measurement of the duration of the rallies, and tri-axial accelerometers measured the intensity of the player’s involvement. A principal component analysis showed that two dimensions explained 54.9% of the total variance in the data and that conative stage and empirical parameters during rallies (duration, intensity of the game) were correlated with axis 1, whereas duration and acceleration data between rallies were correlated with axis 2. A random forest algorithm showed that among the parameters considered, acceleration, duration of the rallies, and time between rallies could predict conative stages with a prediction accuracy above possibility.

This study suggests that performance analysis benefits from the confrontation of subjective and objective data in order to design training plans according to the expertise level of the participants.  相似文献   
46.
Technical difficulties occasionally lead to missing item scores and hence to incomplete data on computerized tests. It is not straightforward to report scores to the examinees whose data are incomplete due to technical difficulties. Such reporting essentially involves imputation of missing scores. In this paper, a simulation study based on data from three educational tests is used to compare the performances of six approaches for imputation of missing scores. One of the approaches, based on data mining, is the first application of its kind to the problem of imputation of missing data. The approach based on data mining and a multiple imputation approach based on chained equations led to the most accurate imputation of missing scores, and hence to most accurate score reporting. A simple approach based on linear regression performed the next best overall. Several recommendations are made regarding the reporting of scores to examinees with incomplete data.  相似文献   
47.
我国职业教育近年来异军突起,招生火,就业率高,优势逐渐显现。为了我国职业院校可持续发展、继续保持良性循环,在此提出"引企入校建深度实训基地,提升学生综合职业力"的观点,并从三个方面阐述:一是我国职业教育实训教学现状与存在的问题,二是引企入校建深度实训基地、提升学生综合职业力的特色,三是实施路径。旨在抛砖引玉,探索出符合我国职业教育实训教学发展特色和规律的途径、方法,为加快推进我国经济发展方式转变提供强有力的高素质技能型人才。  相似文献   
48.
数据结构是高等院校计算机专业的一门重要的专业课。就目前普遍采用的面向过程的教学方式的弊端,提出了进行对象化的教学方式。结合我院实践,提出了一系列的教学步骤,并对此作了分析和探讨。  相似文献   
49.
数据同步技术随着企业对各个信息系统之间数据共享的重视而变得越来越重要,数据同步的方法有很多,本文主要介绍基于ETL技术和基于全表扫描及哈希对比两种数据同步方法。基于ETL技术的数据同步是基于中间逻辑表完成数据转换,再通过主键和时间戳的对比而完成数据同步过程。本文以Kettle工具为例进行分析;基于全表扫描及哈希对比的数据同步是基于视图完成数据转换,再通过hash算法扫描对比而完成数据同步过程。  相似文献   
50.
肖刚 《教育技术导刊》2019,18(10):182-185
数据库同步是实现不同系统之间数据共享的有效方法。现有异构数据库同步模型能有效解决记录的同步新增,但由于同步记录查询基于数据表名和关键字值,若不考虑同步数据库节点变化,将导致数据库不适用于某些遗留系统。针对该问题,提出同步控制和主从记录映射方法,在同步控制层记录主从记录映射关系。在采用双向中间件方法的同步技术基础上,设计基于标准数据格式的数据转换,降低数据转换模块开发维护成本,并根据模型应用WCF框架实现系统。实践应用表明,该模型可实现异构数库之间同步更新。  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