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   747篇
  免费   42篇
电工技术   10篇
综合类   3篇
化学工业   217篇
金属工艺   20篇
机械仪表   17篇
建筑科学   56篇
矿业工程   3篇
能源动力   38篇
轻工业   48篇
水利工程   3篇
石油天然气   5篇
无线电   47篇
一般工业技术   152篇
冶金工业   34篇
原子能技术   3篇
自动化技术   133篇
  2024年   1篇
  2023年   12篇
  2022年   17篇
  2021年   28篇
  2020年   11篇
  2019年   22篇
  2018年   26篇
  2017年   27篇
  2016年   22篇
  2015年   27篇
  2014年   39篇
  2013年   49篇
  2012年   45篇
  2011年   64篇
  2010年   35篇
  2009年   42篇
  2008年   49篇
  2007年   43篇
  2006年   39篇
  2005年   41篇
  2004年   27篇
  2003年   26篇
  2002年   19篇
  2001年   19篇
  2000年   5篇
  1999年   15篇
  1998年   12篇
  1997年   7篇
  1996年   6篇
  1995年   3篇
  1994年   1篇
  1993年   1篇
  1992年   1篇
  1990年   2篇
  1985年   1篇
  1973年   1篇
  1972年   2篇
  1971年   2篇
排序方式: 共有789条查询结果,搜索用时 15 毫秒
11.
The repeated median line estimator is a highly robust method for fitting a regression line to a set of n data points in the plane. In this paper, we consider the problem of updating the estimate after a point is removed from or added to the data set. This problem occurs, e.g., in statistical online monitoring, where the computational effort is often critical. We present a deterministic algorithm for the update working in O(n) time and O(n2) space.  相似文献   
12.
13.
The single‐atom transistor represents a quantum electronic device at room temperature, allowing the switching of an electric current by the controlled and reversible relocation of one single atom within a metallic quantum point contact. So far, the device operates by applying a small voltage to a control electrode or “gate” within the aqueous electrolyte. Here, the operation of the atomic device in the quasi‐solid state is demonstrated. Gelation of pyrogenic silica transforms the electrolyte into the quasi‐solid state, exhibiting the cohesive properties of a solid and the diffusive properties of a liquid, preventing the leakage problem and avoiding the handling of a liquid system. The electrolyte is characterized by cyclic voltammetry, conductivity measurements, and rotation viscometry. Thus, a first demonstration of the single‐atom transistor operating in the quasi‐solid‐state is given. The silver single‐atom and atomic‐scale transistors in the quasi‐solid‐state allow bistable switching between zero and quantized conductance levels, which are integer multiples of the conductance quantum G0 = 2e2/h. Source–drain currents ranging from 1 to 8 µA are applied in these experiments. Any obvious influence of the gelation of the aqueous electrolyte on the electron transport within the quantum point contact is not observed.  相似文献   
14.
Emotional dissonance resulting from an employee's emotional labor is usually considered to lead to negative employee outcomes, such as job dissatisfaction and emotional exhaustion. Drawing on Festinger's (1957) cognitive dissonance theory, we argue that the relationship between service employees' surface acting and job dissatisfaction and emotional exhaustion is moderated by 2 aspects of a service worker's self-concept: the importance of displaying authentic emotions (reflecting the self-concept's self-liking dimension) and the employee's self-efficacy when faking emotions (reflecting the self-competence dimension). A survey of 528 frontline employees from a wide variety of service jobs provides support for the moderating role of both self-concept dimensions, which moderate 3 out of 4 relationships. Theoretical and practical implications are discussed from the perspectives of cognitive dissonance and emotional labor theories. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
15.
16.
17.
Fast camera‐based luminescence‐imaging measurements on perovskite solar cells are presented. The fundamental correlation between the luminescence intensity and the open circuit voltage predicted by the generalised Planck law is confirmed, enabling various quantitative methods for the detection of efficiency‐limiting defects to be applied to this new cell structure. Interstinegly, it is found that this fundamental correlation is valid only for light‐soaked devices. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
18.
19.
The chemical industry is one of the key industrial sectors in Germany and at the same time one of the largest consumers of energy and raw materials. A successful energy transition and the development of a circular economy can only succeed if they are actively supported and shaped by the chemical industry – through the redesign of existing production processes and the exploration and implementation of new process routes. The challenge is to realize this transformation within a very short time and for many production processes, whereby a much larger number of process routes must be explored. Digital technologies are key to master this transformation towards more sustainability, climate, and environmental protection. The KEEN project aims to explore and leverage artificial intelligence (AI) opportunities in process industry. The newly developed AI methods are tested wherever possible in real working environments and production plants to prove the economic benefit, applicability, and reliability of the methods and technologies.  相似文献   
20.
In fluoropolymers, a large portion or even all of the hydrogen atoms in a polymer chain are replaced by fluorine, which results in a number of special properties such as high chemical and temperature resistance. As a result of this combination of properties, these high-performance polymers are not replaceable, or only with difficulty, for some applications. The recycling of polymers and the associated closing of material loops is an essential development task for the entire polymer industry. Materials such as fluoropolymers have a special position due to their chemical composition and their low market volume, as they cannot be recycled together with other bulk polymers at the end of their life cycle. This paper discusses different processes in terms of their technical maturity and suitability to allow fluoropolymers to be fully recycled.  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