全文获取类型
收费全文 | 7616篇 |
免费 | 369篇 |
国内免费 | 374篇 |
专业分类
电工技术 | 135篇 |
技术理论 | 9篇 |
综合类 | 912篇 |
化学工业 | 707篇 |
金属工艺 | 107篇 |
机械仪表 | 224篇 |
建筑科学 | 695篇 |
矿业工程 | 221篇 |
能源动力 | 157篇 |
轻工业 | 320篇 |
水利工程 | 141篇 |
石油天然气 | 101篇 |
武器工业 | 1032篇 |
无线电 | 708篇 |
一般工业技术 | 763篇 |
冶金工业 | 572篇 |
原子能技术 | 170篇 |
自动化技术 | 1385篇 |
出版年
2024年 | 8篇 |
2023年 | 65篇 |
2022年 | 101篇 |
2021年 | 144篇 |
2020年 | 152篇 |
2019年 | 119篇 |
2018年 | 98篇 |
2017年 | 357篇 |
2016年 | 383篇 |
2015年 | 383篇 |
2014年 | 547篇 |
2013年 | 433篇 |
2012年 | 405篇 |
2011年 | 616篇 |
2010年 | 472篇 |
2009年 | 508篇 |
2008年 | 392篇 |
2007年 | 502篇 |
2006年 | 474篇 |
2005年 | 345篇 |
2004年 | 291篇 |
2003年 | 294篇 |
2002年 | 213篇 |
2001年 | 200篇 |
2000年 | 174篇 |
1999年 | 142篇 |
1998年 | 78篇 |
1997年 | 63篇 |
1996年 | 56篇 |
1995年 | 41篇 |
1994年 | 50篇 |
1993年 | 31篇 |
1992年 | 20篇 |
1991年 | 17篇 |
1990年 | 29篇 |
1989年 | 25篇 |
1988年 | 11篇 |
1986年 | 13篇 |
1985年 | 6篇 |
1984年 | 7篇 |
1982年 | 5篇 |
1970年 | 5篇 |
1967年 | 4篇 |
1966年 | 6篇 |
1965年 | 5篇 |
1964年 | 9篇 |
1963年 | 5篇 |
1961年 | 5篇 |
1960年 | 5篇 |
1955年 | 6篇 |
排序方式: 共有8359条查询结果,搜索用时 31 毫秒
1.
Marion Börnhorst Jens Friedland Bjarne Kreitz Emanuele Moioli Gregor Wehinger 《化学,工程师,技术》2021,93(8):1210-1213
In this article, the results of the NaWuReT (Early Career Reaction Engineers) workshop on the topic “Are we doing relevant science?” are presented. The topics “(In)surmountable hurdles for Citizen Scientists in reaction engineering?” and “Circular Economy in reaction engineering with/for society?” were discussed. Therefrom, a variety of ideas and suggestions were extracted. 相似文献
2.
3.
The effect of the emergency perception of bystanders of cyberbullying victims on helping behaviors is often neglected in research on cyberbullying. In this study, we explored the influence of this cognitive factor on cyber-bystanders’ helping tendencies as well as elucidated possible underlying processes. The results of two studies were reported. In Study 1, 150 undergraduates read a true case of a girl experiencing cyberbullying. The results indicated that when the participants perceived the victim’s situation to be more critical (i.e., higher emergency perception), their helping tendencies were stronger, partly through increased state empathy followed by feelings of responsibility to help. In Study 2, we randomly assigned 300 undergraduates to two groups. The low emergency group read the same cyberbullying case as Study 1, whereas the cyberbullying case read by the high emergency group contained additional emergency information of the victim. The results indicated that the high emergency group expressed stronger helping tendencies than did the low emergency group. This effect was caused by a stronger perception that the victim was in an emergency situation, which not only strengthened the participants’ helping tendencies directly but also indirectly through increasing their state empathy and feelings of responsibility to help. 相似文献
4.
Eduardo H. Diniz Erica S. Siqueira Eric van Heck 《Information Technology for Development》2019,25(1):69-91
ABSTRACTCommunity currencies are used to pay for products or services within specific groups defined by geographical boundaries or specific common interests. Financial crises, social emergence in developing countries, and increased access to digital devices have stimulated a growing number of communities worldwide to develop digital currency projects. These projects use technologies ranging from traditional plastic cards to mobile phones and blockchain technologies. Following the design science research approach, this paper analyzes digital community currencies (DCCs) by developing a taxonomy based on platform architecture, governance, transactionality and virtuality. By investigating 22 DCC platforms around the world, 4 groups were distinguished: local, proprietary, commons and cyber. The identification of these four different groups of digital community currencies allows us to better discuss the potentials and limitations of each one of them. The presented taxonomy can be useful to researchers and practitioners both to explain and to design DCC platforms. Discussing each of the emerging categories from the proposed taxonomy helps us to provide insights into DCCs, offering a new theoretical frame for investigating the particular case of digital payment platforms. 相似文献
5.
Science of science has become a popular topic that attracts great attentions from the research community. The development of data analytics technologies and the readily available scholarly data enable the exploration of data-driven prediction, which plays a pivotal role in finding the trend of scientific impact. In this paper, we analyse methods and applications in data-driven prediction in the science of science, and discuss their significance. First, we introduce the background and review the current state of the science of science. Second, we review data-driven prediction based on paper citation count, and investigate research issues in this area. Then, we discuss methods to predict scholar impact, and we analyse different approaches to promote the scholarly collaboration in the collaboration network. This paper also discusses open issues and existing challenges, and suggests potential research directions. 相似文献
6.
7.
Andrew T. Miranda 《Theoretical Issues in Ergonomics Science》2019,20(1):73-83
AbstractLike many scientific topics, Human Factors, and Ergonomics concepts are susceptible to being misunderstood by people unfamiliar with the subject matter. Most of the time these misunderstandings are harmless, like when a safety poster within a work setting encourages employees to 'overcome complacency'. This misunderstanding of complacency suggests it is a motivational aspect of human behaviour correctable with encouragement, whereas the human factors approach to overcoming complacency would be to evaluate how task design could diminish the destructive consequences of unexpected changes within a routine setting. No harm comes from the message within the safety poster, other than some wasted ink and paper, but misconceptions among particular audiences can eventually result in dire consequences for the human operator. This paper presents recent evidence that the concepts are being misapplied by casual consumers of human factors, particularly in the aftermath of accidents within complex systems, in ways detrimental to the core mission of improving the well-being of the human operator. Later, because this special issue presents new ways to demonstrate value via return on investment, practical efforts we can take to overcome such misconceptions are suggested. 相似文献
8.
为将系统故障演化过程(system fault evolution process,SFEP)的文本描述转化为空间故障网络(space fault network,SFN)结构,用于故障分析,本文提出SFEP文本因果关系提取方法,及其与SFN基本结构的转化方法。首先给出SFEP中事件的几种典型因果关系。随后提出因果关系与SFN基本结构的转化流程。本文方法围绕着关键字和因果关系组模式展开,通过模型的不断学习补充和丰富关键字和组模式。最终使方法具备将SFEP文本转化为SFN结构的能力。以飞机起落架故障发生过程文本为例进行了应用,实验结果表明该方法可用于SFEP文本中的因果关系分析,并得到了理想的SFN。完善的关键字和组模式有利于使用计算机智能处理SFEP的SFN。 相似文献
9.
Asli Agirbas 《建筑学研究前沿(英文版)》2020,9(4):940-950
This study aims to test two hypotheses: teaching building information modeling (BIM) in relation to construction science provides students with a remarkable understanding of the nature of construction science (Hypothesis 1), and if the student has positive attitude toward the use of the BIM program, then efficiency by which construction science is taught by its means is improved (Hypothesis 2). Results and process of a case study with a novel teaching methodology were discussed in terms of the benefits of the students. A questionnaire study was conducted on the student group with which the case study was performed to test each student's attitude. Results were evaluated statistically. When BIM is integrated with the teaching of basic construction courses within architecture degree programs, the students understood the building system principles simply and effectively. As a result of the statistical analysis, the students find the applied method effective. Moreover, their attitude toward BIM affects the process. 相似文献
10.
Social media has been widely used for emergency communication both in disaster-affected areas and unaffected areas. Comparing emotional reaction and information propagation between on-site users and off-site users from a spatiotemporal perspective can help better comprehend collective human behavior during natural disasters. In this study, we investigate sentiment and retweet patterns of disaster-affected areas and disaster-unaffected areas at different stages of Hurricane Harvey. The results show that off-site tweets were more negative than on-site tweets, especially during the disaster. As for retweet patterns, indifferent-neutral and positive tweets spread broader than mixed-neutral and negative tweets. However, negative tweets spread faster than positive tweets, which reveals that social media users were more sensitive to negative information in disaster situations. With the development of the disaster, social media users were more sensitive to on-site positive messages than off-site negative posts. This data-driven study reveals the significant effect of sentiment expression on the publication and re-distribution of disaster-related messages. It generates implications for emergency communication and disaster management. 相似文献