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   1495篇
  免费   75篇
  国内免费   41篇
电工技术   55篇
综合类   110篇
化学工业   149篇
金属工艺   32篇
机械仪表   159篇
建筑科学   149篇
矿业工程   51篇
能源动力   39篇
轻工业   154篇
水利工程   16篇
石油天然气   53篇
武器工业   3篇
无线电   92篇
一般工业技术   112篇
冶金工业   43篇
原子能技术   69篇
自动化技术   325篇
  2024年   5篇
  2023年   12篇
  2022年   19篇
  2021年   31篇
  2020年   34篇
  2019年   18篇
  2018年   28篇
  2017年   21篇
  2016年   29篇
  2015年   43篇
  2014年   78篇
  2013年   102篇
  2012年   99篇
  2011年   89篇
  2010年   92篇
  2009年   88篇
  2008年   70篇
  2007年   101篇
  2006年   78篇
  2005年   56篇
  2004年   74篇
  2003年   60篇
  2002年   45篇
  2001年   30篇
  2000年   24篇
  1999年   37篇
  1998年   45篇
  1997年   30篇
  1996年   37篇
  1995年   20篇
  1994年   16篇
  1993年   9篇
  1992年   18篇
  1991年   10篇
  1990年   9篇
  1989年   10篇
  1988年   6篇
  1987年   4篇
  1985年   2篇
  1984年   7篇
  1983年   9篇
  1982年   1篇
  1980年   2篇
  1979年   2篇
  1978年   1篇
  1976年   5篇
  1974年   1篇
  1973年   1篇
  1960年   1篇
  1954年   1篇
排序方式: 共有1611条查询结果,搜索用时 31 毫秒
31.
Many studies have been conducted to determine how to present information on mobile phones in such a way as to enhance usability, but those studies have not considered what information users need for effective decision making. To investigate what users want from mobile phones, we carried out a content preparation study. A questionnaire was constructed based on prior results from website content research, traditional usability studies on consumer electronics, and extensive study on various types of mobile phones; it was completed by 375 Chinese industrial participants. The statistical results revealed nine major factors of mobile phone content: information relating to input/search, functions, operation, multimedia functions, stored files, phone calls, help/service, accessory functions, and messages. Also, users of different ages and genders evidenced different requirements for mobile phone content, especially concerning accessory and multimedia functions. This study suggests guidelines for mobile phone designers targeted at the Chinese market and provides a base for content study of other information appliances.  相似文献   
32.
We consider the determinism checking of XML Schema content models, as required by the W3C Recommendation. We argue that currently applied solutions have flaws and make processors vulnerable to exponential resource needs by pathological schemas, and we help to eliminate this potential vulnerability of XML Schema based systems. XML Schema content models are essentially regular expressions extended with numeric occurrence indicators. A previously published polynomial-time solution to check the determinism of such expressions is improved to run in linear time, and the improved algorithm is implemented and evaluated experimentally. When compared to the corresponding method of a popular production-quality XML Schema processor, the new implementation runs orders of magnitude faster. Enhancing the solution to take further extensions of XML Schema into account without compromising its linear scalability is also discussed.  相似文献   
33.
The purpose of the present study was to examine the prevalence of cyber-bullying through Facebook in a sample of 226 Greek university undergraduates, and to explore whether big five personality characteristics, narcissism, as well as attitudes toward Facebook, technological knowledge and skills were predictive of such behavior. Participants completed a self-report questionnaire measuring the above constructs. Results indicated that almost one third of the sample reported Facebook bullying engagement at least once during the past month, with male students reporting more frequent involvement than females. Bullying through Facebook was predicted by low Agreeableness and more time spent on Facebook only for males, whereas for females none of the studied variables predicted engagement in Facebook bullying. Findings are discussed in terms of prevention and intervention strategies.  相似文献   
34.
The A2-domain of blood coagulation factor VIIIa is non-covalently bound to the A1 and A3 domains via weak intermolecular interactions. Functional instability due to rapid dissociation of A2-domain from the active FVIII in blood presents a major hurdle for the therapeutic applications of FVIIIa to treat Hemophilia-A. To identify the ideal hot-spot residues at the interface of A2 and A1/A3 domains that could enhance the structural stability of FVIIIa, we performed a comprehensive computational mutagenesis study of two A2-domain residues, Asp519 and Glu665, that interface the A1 and A3-domains. Each residue was mutated to 15 uncharged amino-acids and the mutant structures were refined by MD simulations. Based on the estimated relative binding affinities of mutant structures, we predict that the mutation of Asp519 to Leu, Gln, Thr, Val and the mutation of Glu665 to Val, Ile, Met, Asn and Trp enhance the A2-domain binding affinity by more than 20 kcal/mol, compared to the WT structure. We anticipate that these predictions will be valuable for enzymatic studies towards the rational design of FVIIIa synthetic constructs with improved A2-domain binding affinity.  相似文献   
35.
李浩 《自动化博览》2013,(12):78-80,88
并网机组的一次调频功能对于电网的稳定性来说至关重要。随着“两个细则”的发布,电网对一次调频功能的考核越来越严格。在此背景下,本文总结了影响一次调频的11个因素并给出了相应的解决措施,具有一定的借鉴意义。  相似文献   
36.
This paper explores the impacts of essential elements of management on IT application maturity (ITAM). A game theoretical model is established to show that a firm's IT application maturity should match with its essential elements of management. In order to further validate the analytical result, a data set with 137 firms was collected via a survey instrument. Using reliability and factor analysis on the dataset, a four-dimension measurement construct of IT application maturity is proposed together with a three-dimension measurement construct of essential elements of management. Empirical analysis is then conducted to address research questions on the impacts of essential elements of management on IT application maturity. It is found that while a firm's strategic cooperation capability has no significant effect on IT application maturity, its internal coordination capability positively influences all four dimensions of IT application maturity. For the firm's execution capability, although it shows no significant effect on the overall IT application maturity, it does positively affect the technology and man-machine synergy dimensions of IT application maturity. The findings of this study offer practical guidance for organizations to better align their IT application maturity with essential elements of management.  相似文献   
37.
This paper proposes a systematic approach to developing comprehensive guidelines for mobile phone user interface, and presents a case study to validate the approach. The approach applies a systematic combination of three critical factors: general usability principles, UI components and guideline properties to developing guidelines. In the case study, this factor combination approach was very effective in collecting experts’ ideas, creating guidelines and editing them. The resulting style guide can provide comprehensive and useful guidelines for designing mobile phone UI.

Relevance to Industry

UI designers can use the results of the study as a practical method to develop style guides for mobile phone UIs. The approach taken in the study will also be helpful in managing complex guideline information systematically.  相似文献   
38.
39.
In this paper we study an alternative way of treating Polish notation. Instead of proving unique reading for a well-behaved set of terms, we interpret any string of the alphabet in a monoid that extends, in a specifiable sense, the given algebra of functions.  相似文献   
40.
文本相似度的计算在数字图书馆系统里有着广泛的应用前景。该文采用余弦系数和向量空间模型计算文本的相似度,并给出了实现的方法。  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