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   530篇
  免费   54篇
  国内免费   27篇
电工技术   10篇
技术理论   1篇
综合类   41篇
化学工业   8篇
金属工艺   5篇
机械仪表   22篇
建筑科学   93篇
矿业工程   2篇
能源动力   5篇
轻工业   12篇
水利工程   8篇
无线电   28篇
一般工业技术   57篇
冶金工业   120篇
自动化技术   199篇
  2024年   8篇
  2023年   13篇
  2022年   22篇
  2021年   27篇
  2020年   27篇
  2019年   15篇
  2018年   16篇
  2017年   15篇
  2016年   8篇
  2015年   11篇
  2014年   18篇
  2013年   30篇
  2012年   27篇
  2011年   30篇
  2010年   35篇
  2009年   32篇
  2008年   43篇
  2007年   29篇
  2006年   20篇
  2005年   30篇
  2004年   21篇
  2003年   18篇
  2002年   17篇
  2001年   17篇
  2000年   8篇
  1999年   6篇
  1998年   9篇
  1997年   6篇
  1996年   11篇
  1995年   7篇
  1994年   6篇
  1993年   5篇
  1992年   6篇
  1991年   2篇
  1990年   1篇
  1989年   2篇
  1988年   2篇
  1987年   2篇
  1982年   1篇
  1977年   1篇
  1975年   1篇
  1972年   1篇
  1966年   1篇
  1965年   1篇
  1964年   1篇
  1963年   1篇
  1954年   1篇
排序方式: 共有611条查询结果,搜索用时 390 毫秒
41.
化学产品工程作为化学工程学科的一个新方向或化学工程学科的新范式已提出很多年,但学术界对其学科内涵理解不一。本文对化学产品工程的学科内涵进行了分析和探讨,认为其核心是通过过程和设备对产品的纳微结构和复杂大分子结构进行调控;化学产品工程仍隶属过程工程,是面向高附加值产品、实现产品结构可控、定向、高效制备的过程工程。通过与传统的以满足市场需求和提高生产效率为目标的过程开发和放大的化学工程研究类比,提出了化学产品工程的主要研究内容,并讨论了其研究的方法论问题,以推动相关的基础研究工作。  相似文献   
42.
From AlphaGo to ChatGPT,the field of AI has launched a series of remarkable achievements in recent years.Analyzing,comparing,and summarizing these achievements at the paradigm level is important for future AI innovation,but has not received sufficient attention.In this paper,we give an overview and perspective on machine learning paradigms.First,we propose a paradigm taxonomy with three levels and seven dimensions from a knowledge perspective.Accordingly,we give an overview on three basic and tw...  相似文献   
43.
The problem of power allocation in cognitive radio networks plays an important role to improve the efficiency of spectrum utilization. However, most of previous works focus on the power allocation for secondary users in spectrum sharing overlay or spectrum sharing underlay, which needs to frequently handoff between the idle spectrum bands or considers the interference constraints in all spectrum bands respectively. In order to reduce the handoff and fully utilize the spectrum resource, we propose a new spectrum sharing paradigm which not only can just need to adjust the transmit power in spectrum bands instead of frequently handoff between idle spectrum bands, but can fully utilize the spectrum resource as we only consider the interference power constraints in active spectrum bands rather than in all spectrum bands. Then based on this new spectrum sharing paradigm and the constraint conditions, we study the distributed power allocation for secondary users and formulate the optimization problem as a non-cooperative game problem, after that the variational inequality approach is used to solve this game problem and a Nash equilibria solution is got, finally simulation results are illustrated to demonstrate the performance of the proposed scheme.  相似文献   
44.
Proactive adjustments of response strategies in the stop-signal paradigm.   总被引:2,自引:0,他引:2  
In the stop-signal paradigm, fast responses are harder to inhibit than slow responses, so subjects must balance speed in the go task with successful stopping in the stop task. In theory, subjects achieve this balance by adjusting response thresholds for the go task, making proactive adjustments in response to instructions that indicate that relevant stop signals are likely to occur. The 5 experiments reported here tested this theoretical claim, presenting cues that indicated whether or not stop signals were relevant for the next few trials. Subjects made proactive response-strategy adjustments in each experiment: Diffusion-model fits showed that response threshold increased when participants expected stop signals to occur, slowing go responses and increasing accuracy. Furthermore, the results show that subjects can make proactive response-strategy adjustments on a trial-by-trial basis, suggesting a flexible cognitive system that can proactively adjust itself in changing environments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
45.
We analyze the feasibility of a novel, hydrogen fuel cell electric generator to provide power with zero noise and emissions for myriad ground based applications. The hydrogen fuel cell electric generator utilizes a novel, scalable apparatus that safely generates hydrogen (H2) on demand according to a novel method, using a controlled chemical reaction between water (H2O) and sodium (Na) metal that yields hydrogen gas of sufficient purity for direct use in fuel cells without risk of contaminating sensitive catalysts. The sodium hydroxide (NaOH) byproduct of the hydrogen producing reaction, is collected within the apparatus for later reprocessing by electrolysis, to recover the Na reactant. The detailed analysis shows that the novel, hydrogen fuel cell electric generator will be capable of meeting the clean power requirements for residential and commercial buildings including single family homes and light commercial establishments under a wide range of geographic and climatic conditions.  相似文献   
46.
可持续水资源管理量化研究的关键问题   总被引:1,自引:1,他引:0  
“可持续水资源管理”是当今世界水问题研究的热点之一 [1 ] 。目前 ,国际上对可持续水资源管理的研究还处在对量化研究的积极探索阶段。由于可持续水资源管理量化研究涉及的内容广泛、许多基础问题还没有完全解决 ,使得可持续水资源管理量化研究方法还很不成熟。本文在总结前期研究成果的基础上 ,探讨了目前研究的几个关键问题 ,即准则问题、指标体系问题、基础模型问题、量化方法问题  相似文献   
47.
在邓宁的折衷范式下阐述了我国商业银行进行对外直接投资所具有的所有权优势、区位优势和内部化优势。随着我国经济的发展和非金融企业对外投资的增加,其对外直接投资规模会不断扩大,但政府需为其创造一个有利的环境,并在折衷范式框架下具体分析了面临的问题和可采取的对策。  相似文献   
48.
应用ATM网络实现电力系统远程实时监控   总被引:4,自引:0,他引:4  
提出了电力系统实时决策系统中超远程强实时通信的设计与实现方法,在网络拓扑上采用星形的多智能客户机组/中央服务器群集模式;网络物理载体采用能够提供高带宽和极短时延的基于光放大技术的同步光纤网;在通信方式的选择上,采用基于无确认的方式并且能够提供良好的实时服务的兼容性的ATM技术,通过对可靠性和实时通信时延进行精确估算,表明采用此设计方式,可以满足电力系统实时决策和紧急控制对上千千米超远程通信的可靠性和实时性要求。  相似文献   
49.
Abstract.  In this journal, Chen and Hirschheim have provided a historical analysis of positivist and interpretivist research paradigms and methodologies in the 10 years following the much cited work of Orlikowski and Baroudi. In this paper, we investigate the mysterious case of the missing paradigm – that of the critical approach to information systems (IS) research. We take Chen and Hirschheim's survey as our starting point and aim to fill the gap left by the absence of the critical paradigm in their analysis and make some criticisms of their method. Recent years have seen the growth of IS research that consciously adopts a critical perspective. This paper charts the development of critical IS research over the period of 1991–2001, adding some comments on more recent developments. We conclude by critically reflecting on the current development of critical research in the field of IS.  相似文献   
50.
Facing the scale, heterogeneity and dynamics of the global computing platform emerging on top of the Internet, autonomic computing has been raised recently as one of the top challenges of computer science research. Such a paradigm calls for alternative programming abstractions, able to express autonomic behaviours. In this quest, nature-inspired analogies regained a lot of interest. More specifically, the chemical programming paradigm, which envisions a program’s execution as a succession of reactions between molecules representing data to produce a result, has been shown to provide some adequate abstractions for the high-level specification of autonomic systems.  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