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   6845篇
  免费   198篇
  国内免费   104篇
电工技术   83篇
综合类   655篇
化学工业   691篇
金属工艺   91篇
机械仪表   347篇
建筑科学   310篇
矿业工程   39篇
能源动力   46篇
轻工业   107篇
水利工程   13篇
石油天然气   20篇
武器工业   10篇
无线电   412篇
一般工业技术   147篇
冶金工业   99篇
原子能技术   15篇
自动化技术   4062篇
  2024年   6篇
  2023年   57篇
  2022年   70篇
  2021年   171篇
  2020年   137篇
  2019年   96篇
  2018年   80篇
  2017年   114篇
  2016年   222篇
  2015年   201篇
  2014年   639篇
  2013年   435篇
  2012年   647篇
  2011年   986篇
  2010年   548篇
  2009年   467篇
  2008年   528篇
  2007年   484篇
  2006年   298篇
  2005年   168篇
  2004年   157篇
  2003年   155篇
  2002年   145篇
  2001年   76篇
  2000年   49篇
  1999年   57篇
  1998年   30篇
  1997年   20篇
  1996年   16篇
  1995年   12篇
  1994年   14篇
  1993年   7篇
  1992年   6篇
  1991年   3篇
  1990年   3篇
  1989年   5篇
  1988年   6篇
  1987年   2篇
  1986年   6篇
  1985年   9篇
  1984年   2篇
  1983年   2篇
  1982年   1篇
  1981年   2篇
  1979年   5篇
  1978年   1篇
  1974年   1篇
  1971年   1篇
排序方式: 共有7147条查询结果,搜索用时 31 毫秒
1.
教学行为分析作是教学质量分析的重要组成部分,也是教学引导与反馈机制的重要依据。文章阐述了人工智能(AI)的含义及发展历程,重点分析总结了教学行为分析方法及AI在教学行为分析上的应用。文章以东南大学电工电子在线实验为研究平台,探索分析了AI技术在实验教学行为分析上的可行性,梳理了基于专家系统的在线实验分析系统的设计思路,充分探讨了“智能”教育在实验教学中的深刻内涵。  相似文献   
2.
In the current study, a single cell of a planar SOFC is firstly modeled in 3D using commercial SOFC module of ANSYS Fluent and the results are validated against the experimental investigations in the literature. Many researchers have used ANSYS Fluent for simulating solid oxide fuel cells. However, there is a huge gap in the literature on explaining the detailed procedure that should be followed in order to use this software effectively. A thorough step-by-step approach is presented to provide a deep insight into the software. Thereafter, a simplified quasi-2D method with infinitely shorter computational time is developed and the results are compared with the 3D model. It is found that the reduced model is capable of being utilized as an alternate method for both online diagnosis and designing active control strategies.  相似文献   
3.
The current study set out to investigate to what extent ISIS is bolstering its jihadist ideology on a ‘cut-and-paste’ or ‘cherry-picked’ version of Islam in their renowned online propaganda magazine Dabiq. The main objective was to examine in a systematic and quantitative way to what extent ISIS utilizes the Koran in an atomistic, truncated and tailored manner to bolster its religious legitimacy. A total of 15 issues of Dabiq and 700 Koranic references were scrutinized. By means of a quantitative analysis we developed an innovative taxonomy of Koranic chapters and verses (i.e. surahs and ayat, respectively) on the basis of their appearance in Dabiq. Our large-scale data analysis provide consistent empirical evidence for severe decontextualization practices of the Koran in three ways: (1) a thin, Medinan-dominated religious layer, (2) ayah mutilation, and (3) clustered versus exclusive mentions. Limitations and implications for future research, policy makers and CVE initiatives are discussed.  相似文献   
4.
《云南化工》2019,(10):145-147
催化裂化催化剂应具有良好的颗粒分布,以保证良好的流化状态。一般要求催化剂颗粒<40μm的不大于25%,40~111μm不小于50%,>111μm的不大于30%。目前催化裂化催化剂生产过程中通常采用压力式喷雾干燥成型工艺,用高压泵把制备好的胶体在与热空气的接触中,迅速脱去水分汽化,即得到粉状或颗粒状干燥产品。现有生产装置在生产过程中,因分析结果滞后,无法及时指导装置调整催化剂成品的粒度分布,特引进使用了在线粒度分析仪。通过对该分析仪的简单研究,介绍了该分析仪的使用现状,并对使用中出现的问题进行了简单总结。  相似文献   
5.
This work describes a novel teaching methodology and its application in a subject framed in the last course of the master’s degree in Chemical Engineering at the University of Seville. The main aim consists of promoting a way to facilitate professional practice in this field to the students. Authors also aim at guiding the transition to the new learning requirements demanded by the European Higher Education Area (EHEA).The novel methodology is based on the development of a detailed design of a pilot plant that can be further evaluated by the students themselves. Students are also allowed to run experiments at the facility and carry out several standard tests to verify the quality of the results of their works. The novelty of this proposal consists of incorporating a real installation available in our department to drive new learning methodologies applied in Chemical Engineering curricula. The methodology is distributed across several tasks: training (self-learning), project execution and supervision, comparison with a real installation and pilot plant experiences. The application of the proposed teaching methodology provided quality didactic material production, high satisfaction of the students with the new learning approach and the fact that they gained practical experience at industrial scale.  相似文献   
6.
There is growing recognition that blockchain technology has significant potential to alter how organizations and people work and communicate. However, theoretical guidance concerning how organizations leverage blockchain technology to enhance value creation for users is still limited. Grounded in the socio-technical perspective and leveraging the rich data obtained from case analyses of blockchain-enabled online communities, this paper develops a theoretical model to identify the core value drivers that blockchain enables for online communities. The core value drivers include: a reputation-value system, data ownership mechanisms, and verification & tracking mechanisms. Our findings suggest that these three value drivers enhance value creation of online communities by motivating participation and protecting contributions.  相似文献   
7.
We propose a Discussion Logic-based Text Analytics (DiLTA) framework, which combines theories developed in social science and text mining fields. The framework extracts features that uncover discussion logic and uses these features in analyzing online discussions. A series of models are proposed including conversation disentanglement, coherence analysis, and visualization. Validation experiments showed that DiLTA achieved significantly superior performance over existing text analytics methods in reconstructing internal structure. A case study using DiLTA-enabled visualization on a healthcare forum illustrates the great potential of DiLTA in assisting comprehension of the internal linkage, structure, and logic of online group discussions.  相似文献   
8.
The extent to which the deliberative scenario brackets socio-economic inequalities (i.e., functioning as an ideal public sphere) has been long-debating. This study empirically addresses this question in the online setting. We test whether offline advantages (i.e., economic and cultural capitals) can be translated into power in online deliberation and how their dynamic relations further influence interlocutors’ deliberation experience (i.e., perceived procedural fairness and validity claim). Power is conceptualized as network power, including prestige (indegree), leadership (outdegree), and brokering power (betweenness). A national sample of Singaporeans participated in a three-week online deliberation, and network power is measured based on the web log. The participants answered a two-wave (i.e., pre- and post-deliberation) survey to indicate individual attributes. Structural equation modeling finds that online deliberation brackets as well as reinforces offline status. Economic capital is suppressed while cultural capital translates into network power, which further influences interlocutors’ evaluation of the deliberation.  相似文献   
9.
对英语教学质量实施科学化的评价关系到英语教学质量的提升,为减少主观因素的影响,本文提出一种ELM的教学质量评价方法,该种方法将可以在很大程度上提高教学质量评价的精度。对影响英语教学质量的12个指标进行打分,以此作为ELM的输入,同时将英语教学质量的综合得分作为ELM的输出。评价结果表明,基于EIM的英语教学质量评价结果比SVM、BP具有了很大程度的提升,为实施英语教学质量的评价提供了参考。  相似文献   
10.
The present study explored the relation between exchanging social support on online teacher groups and teacher self-efficacy. An online survey was conducted inside a massive Facebook teacher group, and 584 elementary school teachers provided information regarding Facebook use, self-efficacy for creative teaching, and the extent to which they provided and received support on the online teacher group. Results showed that teacher self-efficacy varied as a function of years of teaching experience, length of group membership, and the extent to which teachers provided and received social support on the online teacher group. Furthermore, the providing of online support predicted teacher self-efficacy after taking into account the effects of teaching experience and group membership. The findings are discussed in terms of the features and importance of social support exchange on online teacher support groups.  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