全文获取类型
收费全文 | 37191篇 |
免费 | 880篇 |
国内免费 | 1094篇 |
专业分类
教育 | 20314篇 |
科学研究 | 8326篇 |
各国文化 | 44篇 |
体育 | 3133篇 |
综合类 | 2233篇 |
文化理论 | 81篇 |
信息传播 | 5034篇 |
出版年
2024年 | 14篇 |
2023年 | 201篇 |
2022年 | 562篇 |
2021年 | 980篇 |
2020年 | 1204篇 |
2019年 | 1057篇 |
2018年 | 908篇 |
2017年 | 899篇 |
2016年 | 1079篇 |
2015年 | 1331篇 |
2014年 | 2864篇 |
2013年 | 3101篇 |
2012年 | 3287篇 |
2011年 | 3322篇 |
2010年 | 2154篇 |
2009年 | 2078篇 |
2008年 | 2087篇 |
2007年 | 2363篇 |
2006年 | 2219篇 |
2005年 | 1801篇 |
2004年 | 1499篇 |
2003年 | 1203篇 |
2002年 | 918篇 |
2001年 | 677篇 |
2000年 | 444篇 |
1999年 | 232篇 |
1998年 | 155篇 |
1997年 | 118篇 |
1996年 | 77篇 |
1995年 | 56篇 |
1994年 | 61篇 |
1993年 | 52篇 |
1992年 | 41篇 |
1991年 | 36篇 |
1990年 | 18篇 |
1989年 | 32篇 |
1988年 | 4篇 |
1985年 | 4篇 |
1983年 | 1篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1957年 | 18篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Simona Balbi Michelangelo Misuraca Germana Scepi 《Information processing & management》2018,54(4):674-685
Web 2.0 allows people to express and share their opinions about products and services they buy/use. These opinions can be expressed in various ways: numbers, texts, emoticons, pictures, videos, audios, and so on. There has been great interest in the strategies for extracting, organising and analysing this kind of information. In a social media mining framework, in particular, the use of textual data has been explored in depth and still represents a challenge. On a rating and review website, user satisfaction can be detected both from a rating scale and from the written text. However, in common practice, there is a lack of algorithms able to combine judgments provided with both comments and scores. In this paper we propose a strategy to jointly measure the user evaluations obtained from the two systems. Text polarity is detected with a sentiment-based approach, and then combined with the associated rating score. The new rating scale has a finer granularity. Moreover, also enables the reviews to be ranked. We show the effectiveness of our proposal by analysing a set of reviews about the Uffizi Gallery in Florence (Italy) published on TripAdvisor. 相似文献
22.
科学数据共享研究现状与展望 总被引:2,自引:0,他引:2
[目的/意义] 分析科学数据共享的研究现状及其发展趋势,为促进国内相关理论研究与实践进展提供参考。[方法/过程] 通过对国内外文献进行梳理和归纳,提炼出与科学数据共享研究相关的三大类主题:科学数据共享发展需求、科学数据管理共享模式与机制和科学数据服务共享度与服务效果,并构建科学数据共享管理分析框架,该框架体现上述三类主题之间的因果关联,强调科学数据共享管理与服务的合理面、重要度、关键性。[结果/结论] 国内外现有研究尚存不足,未来研究在加强实证研究、着眼管理机制完善的同时,还需注重共享服务模式的创新。 相似文献
23.
Surabhi Verma Som Sekhar Bhattacharyya Saurav Kumar 《Information processing & management》2018,54(5):791-806
Research on the adoption of systems for big data analytics has drawn enormous attention in Information Systems research. This study extends big data analytics adoption research by examining the effects of system characteristics on the attitude of managers towards the usage of big data analytics systems. A research model has been proposed in this study based on an extensive review of literature pertaining to the Technology Acceptance Model, with further validation by a survey of 150 big data analytics users. Results of this survey confirm that characteristics of the big data analytics system have significant direct and indirect effects on belief in the benefits of big data analytics systems and perceived usefulness, attitude and adoption. Moreover, there are mediation effects that exist among the system characteristics, benefits of big data analytics systems, perceived usefulness and the attitude towards using big data analytics system. This study expands the existing body of knowledge on the adoption of big data analytics systems, and benefits big data analytics providers and vendors while helping in the formulation of their business models. 相似文献
24.
Wrist movements have been identified as an important factor in producing a successful golf swing, with their complex motion influencing both club head velocity and orientation. However, a detailed analysis of wrist angles is lacking in the literature. The purpose of this study was to determine kinematics across wrists and club head characteristics during the golf swing under weak, neutral and strong grip conditions. Twelve professional male golfers executed 24 shots using a driver under three grip conditions. A six degrees of freedom analysis of the hand with respect to the distal forearm was performed using a 10-camera three-dimensional motion capture system. Differences in joint angles were explored using repeated measures ANOVAs at key swing events (onset, top of backswing and impact), in addition club head velocity and clubface angle at impact were also explored. Main findings revealed significant differences in flexion/extension and internal/external rotation for both wrists at all swing events, whereas fewer significant interactions were found in ulnar/radial deviation across grips for both wrists at all events. Clubface angle only differed significantly between the weak and the strong and neural grips, presenting a more ‘open’ clubface to the intended hitting direction. This study is the first to explore tri-planar wrist movement and the effect of different grips, such analysis has implications for coaching knowledge and practice and should inform future research into different aspects of skill, technique analysis and may inform injury mechanisms/prevention. 相似文献
25.
This paper responds to a trend of contracting out subjective well-being econometrics to demonstrate social return on investment (SROI) for evidence-based policy-making. We discuss an evolving ecology of ‘external’ research taking place ‘between’ the academy and commercial consultancy. We then contextualise this as waves of research methodologies and consultancy for the cultural sector. The new model of ‘external between’ consultancy research for policy is not only placed between the University and the market, but also facilitates discourse between policy sectors, government, the media and the academy. Specifically, it enables seductive but selective arguments for advocacy that claim authority through academic affiliation, yet are not evaluated for robustness. To critically engage with an emergent form of what Stone calls ‘causal stories’, we replicate a publicly funded externally commissioned SROI model that argues for the value of cultural activities to well-being. We find that the author’s operationalisation of participation and well-being are crucial, yet their representation of the relationship problematic, and their estimates questionable. This case study ‘re-performs’ econometric modelling national-level survey data for the cultural sector to reveal practices that create norms of expertise for policy-making that are not rigorous. We conclude that fluid claims to authority allow experimental econometric models and measures to perform across the cultural economy as if ratified. This new model of advocacy research requires closer academic consideration given the changing research funding structures and recent attention to expertise and the contracting out of public services. 相似文献
26.
Elizabeth Joan Kelly 《Journal of Web Librarianship》2018,12(1):28-45
This article outlines evidence-based methods for cultural heritage institutions to look for news and mentions about their collections and services online. Google Alerts were created for repository names, websites, and finding aid websites for 66 institutions randomly selected from the Archive Grid database. Results were analyzed to determine Google Alerts' accuracy, what types of institutions would benefit most from using Google Alerts, what the content of the sources found by the alerts was, what types of publications returned the most results, and if Google Alerts could also identify image reuse. While Google Alerts' accuracy for returning usable results for analysis was not very high, the structure of alert e-mails makes discarding irrelevant results simple and quick. Mid- to large-sized museums and institutions staging frequent exhibits and events, as well as those with active collections, return the largest number of alerts. News publications and social media publish the most content related to cultural heritage institutions. Though the sample set was small, Google Alerts also was able to identify image reuse. 相似文献
27.
[目的/意义]为了深入了解科研众筹平台中的项目情况,本文对科研众筹项目的基本特征、研究主题和不同类型科研众筹项目的属性对比进行研究。[研究设计/方法]首先对科研众筹的起源、价值和运作模式进行了梳理;随后爬取了科研众筹平台Experiment的项目信息,并对该平台中科研项目的发起者、背书者、项目记录、所属学科、资助情况等进行特征描述;基于LDA模型对科研众筹项目主题进一步细化,并对不同资金筹集和不同主题分类情况下的科研众筹项目的属性差异进行比较分析。[结论/发现]科研众筹主题主要集中在生物学和生态学两个领域,不同资金筹集达成情况的科研众筹项目在项目背书者数量、信息记录次数和讨论次数上具有显著差异;不同主题的科研众筹项目在其讨论次数上具有显著差异。同时,是否提供视频和是否参与资助挑战在不同资金筹集达成情况和不同主题的科研众筹项目上均具有显著差异。[创新/价值]深入分析了科研众筹平台中项目主题及属性对比情况,对科研众筹平台优化信息审核机制、社交机制和信息展示机制具有一定的参考价值。 相似文献
28.
[目的/意义]从用户动机视角对Altmetrics指标的本质和价值进行分析,使Altmetrics的应用更为科学合理。[研究设计/方法]首先对相关文献中的动机进行组织提炼与规范化表述。在此基础上引入用户行为理论解释和分析用户动机体现的指标价值。再选取Twitter提及量指标,使用内容分析法进行案例研究。[结论/发现]提炼出19种用户动机,其中有6种动机会降低指标应用价值。[创新/价值]探索Altmetrics数据的产生机制,在一定程度上回答了Altmetrics指标可用性问题。 相似文献
29.
ABSTRACT Historic Japanese textiles from over 1000 years ago generally show marked deterioration and only very rare examples show their original forms and much information about textile reproduction has been lost. The replication of textile braids lacks systematic methodology and is still being practiced by only few individual braiding experts. The recreation of original braids as close as possible to original braids is a part of Japan’s intangible cultural heritage. The aim of this study is to clarify the decision-making procedure through which the braiding experts can decipher the original braiding structures. As a preliminary study of this project, interviews of a braid researcher and a replicating expert, Makiko Tada were performed regarding her working practices. It is important to clarify the braiding parameters for structural analysis such as the number of transits and the balance of ridges, and it became clear that the orientation of multiple colored threads plays an important role. The expert’s replicate works were also analyzed using a text-mining statistical technique to clarify the relationship of braiding parameters. The relationship between each braiding parameter and production method such as loop manipulation and Taka-dai became clear. As a result, the process of deciphering the original braid structure has been compiled in simplified workflows, which could contribute to the standardization and improvement in efficiency of replication of cultural property braids. 相似文献
30.