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   5971篇
  免费   681篇
  国内免费   154篇
电工技术   250篇
综合类   746篇
化学工业   173篇
金属工艺   46篇
机械仪表   98篇
建筑科学   1480篇
矿业工程   714篇
能源动力   114篇
轻工业   876篇
水利工程   320篇
石油天然气   308篇
武器工业   28篇
无线电   221篇
一般工业技术   374篇
冶金工业   325篇
原子能技术   58篇
自动化技术   675篇
  2024年   28篇
  2023年   85篇
  2022年   164篇
  2021年   232篇
  2020年   242篇
  2019年   152篇
  2018年   157篇
  2017年   185篇
  2016年   211篇
  2015年   220篇
  2014年   438篇
  2013年   408篇
  2012年   392篇
  2011年   440篇
  2010年   356篇
  2009年   370篇
  2008年   351篇
  2007年   357篇
  2006年   293篇
  2005年   282篇
  2004年   250篇
  2003年   210篇
  2002年   182篇
  2001年   121篇
  2000年   114篇
  1999年   89篇
  1998年   79篇
  1997年   53篇
  1996年   67篇
  1995年   51篇
  1994年   40篇
  1993年   27篇
  1992年   31篇
  1991年   14篇
  1990年   6篇
  1989年   18篇
  1988年   4篇
  1987年   5篇
  1986年   12篇
  1985年   8篇
  1983年   3篇
  1982年   6篇
  1981年   5篇
  1977年   3篇
  1976年   4篇
  1975年   4篇
  1974年   4篇
  1962年   3篇
  1958年   3篇
  1955年   4篇
排序方式: 共有6806条查询结果,搜索用时 15 毫秒
61.
电阻率法是电法找水应用中历史较长、理论研究较为完善、应用最为广泛的一种方法。通过对高密度电阻率法的基本原理和不同装置类型的介绍及其在马山变电所新建工程场地水文勘察中的应用,为合理布置最佳水井井位提供水文物探依据。  相似文献   
62.
Librarians can improve their online tutorials by borrowing usability testing techniques from the computer science field to improve the human-computer interface. This study involved a multimethod usability test of librarian-created tutorials to determine what students learned, how they felt on several affective questions, and what they suggested for improving the tutorials. Results of pre- and post-tests showed that student knowledge increased, and surveys and focus group findings lean to several suggestions for improving engagement and placing tutorials where they will be most effective. This case study demonstrates the value of user input to improve the effectiveness of online instruction for information literacy.  相似文献   
63.
This study aims to address the paradigms of consumers’ adoption behavior for mobile government, posits the factors which pursue citizens’ intention to adopt mobile government services, and reveals the impact of cultural dimensions in perceiving driving factors of mobile government adoption. The mobile government adoption model was developed and tested among users of three different countries, namely Bangladesh, Canada, and Germany. The finding suggests the rationale that cross-cultural differences impact consumers’ perception of mobile government adoption behavior.  相似文献   
64.
近年来,岩土工程勘察技术发展得非常快,研究领域不断拓展,取得了较多的成就。但是,在发展过程中也存在一些不足。重点分析了岩土工程勘察工作,并结合实际工作提出一些个人意见,以期能为相关工作提供帮助。  相似文献   
65.
The study aimed to examine the relationship between green consumption value, satisfaction, and loyalty of driving hybrid cars among elderly consumers. Data were collected from a cross‐sectional survey of 314 elderly consumers who purchased hybrid cars in the United States. A partial least squares analysis revealed that elderly consumers’ social, price, and quality values positively influenced the satisfaction of their hybrid car experience, and their satisfaction significantly influenced their loyalty of hybrid car. The relationship between green consumption value, satisfaction, and loyalty toward driving hybrid cars among elderly consumers revealed insight into their value orientations toward the hybrid car. Special efforts are suggested in promoting hybrid car use to elderly consumer groups. Marketers should pay attention to changing beliefs and increasing perceived values of driving a hybrid car for consumers to encourage them to use green products.  相似文献   
66.
Database query verification schemes provide correctness guarantees for database queries. Typically such guarantees are required and advisable where queries are executed on untrusted servers. This need to verify query results, even though they may have been executed on one’s own database, is something new that has arisen with the advent of cloud services. The traditional model of hosting one’s own databases on one’s own servers did not require such verification because the hardware and software were both entirely within one’s control, and therefore fully trusted. However, with the economical and technological benefits of cloud services beckoning, many are now considering outsourcing both data and execution of database queries to the cloud, despite obvious risks. This survey paper provides an overview into the field of database query verification and explores the current state of the art in terms of query execution and correctness guarantees provided for query results. We also provide indications towards future work in the area.  相似文献   
67.
根据南水北调中线一期工程建设过程中的科技攻关,本文重点介绍了长距离自流输水线路输水型式选择、施工测量控制、混凝土重力坝再加高和软基中承受内水压力的水工隧洞设计施工中的几个关键技术问题,系统阐述了上述关键技术问题的解决思路和作者的再思考。  相似文献   
68.

A group of users in Copenhagen were asked to evaluate how important a number of user interface characteristics were for them. The results show high importance of efficient daily use and of possibilities for exploratory learning while tutorial materials were of less importance. Users also were asked to evaluate four usability aspects of a number of popular programs. Results show that the quality pleasant to work with has the largest impact on evaluations of overall user‐friendliness while users seem able to view usability independently from the number of features in an application.  相似文献   
69.
Application development productivity is becoming an increasingly important issue in the MIS department. Unfortunately, dramatic improvements in hardware performance have not been matched with corresponding advances in software development, even though there have been significant investments in productivity tools. This article identifies a range of productivity tools and presents results from a survey of MIS managers that reveals which specific tools are being used and their relative importance to software development productivity.  相似文献   
70.
Psychologists are an understudied population in terms of information needs and information seeking behavior. This article provides theoretical analysis accompanied with some empirical evidence drawn from a nationwide survey of psychologists working in the Greek National Healthcare System (GNHS). The empirical study was conducted during the spring of 2011, through a specially designed questionnaire distributed to all psychologists within GNHS. Psychologists seek information for patient consultation purposes and for knowledge updating; they prefer using their personal library, internet search engines, and their colleagues as information sources, while the main obstacles they face include the lack of hospital libraries. This research identified the need to more strongly link hospital library services to health psychologists on the grounds of their information needs and behaviors.  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