全文获取类型
收费全文 | 14867篇 |
免费 | 1957篇 |
国内免费 | 1544篇 |
专业分类
电工技术 | 713篇 |
技术理论 | 4篇 |
综合类 | 1914篇 |
化学工业 | 388篇 |
金属工艺 | 297篇 |
机械仪表 | 1036篇 |
建筑科学 | 798篇 |
矿业工程 | 171篇 |
能源动力 | 180篇 |
轻工业 | 287篇 |
水利工程 | 242篇 |
石油天然气 | 342篇 |
武器工业 | 203篇 |
无线电 | 1296篇 |
一般工业技术 | 1544篇 |
冶金工业 | 682篇 |
原子能技术 | 109篇 |
自动化技术 | 8162篇 |
出版年
2024年 | 116篇 |
2023年 | 340篇 |
2022年 | 518篇 |
2021年 | 540篇 |
2020年 | 496篇 |
2019年 | 444篇 |
2018年 | 369篇 |
2017年 | 420篇 |
2016年 | 552篇 |
2015年 | 548篇 |
2014年 | 760篇 |
2013年 | 973篇 |
2012年 | 878篇 |
2011年 | 1025篇 |
2010年 | 871篇 |
2009年 | 955篇 |
2008年 | 977篇 |
2007年 | 1125篇 |
2006年 | 995篇 |
2005年 | 819篇 |
2004年 | 739篇 |
2003年 | 692篇 |
2002年 | 538篇 |
2001年 | 461篇 |
2000年 | 406篇 |
1999年 | 328篇 |
1998年 | 228篇 |
1997年 | 161篇 |
1996年 | 163篇 |
1995年 | 178篇 |
1994年 | 129篇 |
1993年 | 118篇 |
1992年 | 95篇 |
1991年 | 85篇 |
1990年 | 64篇 |
1989年 | 67篇 |
1988年 | 53篇 |
1987年 | 22篇 |
1986年 | 24篇 |
1985年 | 17篇 |
1984年 | 8篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1980年 | 10篇 |
1979年 | 7篇 |
1963年 | 4篇 |
1960年 | 3篇 |
1959年 | 3篇 |
1958年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
51.
52.
The objective of this study is to explore the possibility of capturing the reasoning process used in bidding a hand in a bridge
game by an artificial neural network. We show that a multilayer feedforward neural network can be trained to learn to make
an opening bid with a new hand. The game of bridge, like many other games used in artificial intelligence, can easily be represented
in a machine. But, unlike most games used in artificial intelligence, bridge uses subtle reasoning over and above the agreed
conventional system, to make a bid from the pattern of a given hand. Although it is difficult for a player to spell out the
precise reasoning process he uses, we find that a neural network can indeed capture it. We demonstrate the results for the
case of one-level opening bids, and discuss the need for a hierarchical architecture to deal with bids at all levels. 相似文献
53.
就工程项目管理企业知识管理建设框架进行了理论的阐述,从建立支持企业知识共享、创新的平台和促进该平台运作的机制提出了知识管理中最重要的两点,指出进行企业知识管理建设对企业未来发展具有重要的影响。 相似文献
54.
应用型机械本科专业教学体系改革研究与实践 总被引:4,自引:0,他引:4
根据当前高等教育改革与发展的指导思想,紧紧围绕国家实施制造业信息化建设工程为背景,积极配合打造浙江先进制造业基地建设,结合现代机械专业结构调整,本着交叉、复合、应用型人才的培养目标,塑造具有宽口径、厚基础和强创新意识的人才培养理念,以数字化设计制造为核心,以机械技术、电子技术、信息技术和管理学科结合为主线,突出知识综合与创新能力,强调专业实践与专业知识的有效结合,有的放矢实施机械专业教学改革与实践。 相似文献
55.
Predictive Maintenance can provide an increase in safety, quality and availability in industrial plants. However, the setting up of a Predictive Maintenance Programme is a strategic decision that until now has lacked analysis of questions related to its setting up, management and control. In this paper, an evaluation system is proposed that carries out the decision making in relation to the feasibility of the setting up. The evaluation system uses a combination of tools belonging to operational research such as: Analytic Hierarchy Process, decision rules and Bayesian tools. This system is a help tool available to the managers of Predictive Maintenance Programmes which can both increase the number of Predictive Maintenance Programmes set up and avoid the failure of these programmes. The Evaluation System has been tested in a petrochemical plant and in a food industry. 相似文献
56.
Power deposition profiles generated by Ion Cyclotron Resonance Heating (ICRH) in non-circular tokamaks are studied using a ray-tracing technique. The simulation results for the Experimental Advanced Superconductor Tokamak (EAST) D-shaped plasma are presented. It is indicated that the spatial distributions of plasma parameters (plasma density, species temperature, minority ion concentration, etc.) have an significant influence on the power deposition profiles. The findings may be highly useful to the planned plasma heating and experiments in EAST. 相似文献
57.
Hyun-Ho Choi Sang-Yoon Lee Il-Yoon Choi Hyo-Nam Cho Sankaran Mahadevan 《Reliability Engineering & System Safety》2006,91(6):674-688
Until now, in many forensic reports, the failure cause assessments are usually carried out by a deterministic approach so far. However, it may be possible for the forensic investigation to lead to unreasonable results far from the real collapse scenario, because the deterministic approach does not systematically take into account any information on the uncertainties involved in the failures of structures.Reliability-based failure cause assessment (reliability-based forensic engineering) methodology is developed which can incorporate the uncertainties involved in structural failures and structures, and to apply them to the collapsed bridge in order to identify the most critical failure scenario and find the cause that triggered the bridge collapse. Moreover, to save the time and cost of evaluation, an algorithm of automated event tree analysis (ETA) is proposed and possible to automatically calculate the failure probabilities of the failure events and the occurrence probabilities of failure scenarios. Also, for reliability analysis, uncertainties are estimated more reasonably by using the Bayesian approach based on the experimental laboratory testing data in the forensic report. For the applicability, the proposed approach is applied to the Hang-ju Grand Bridge, which collapsed during construction, and compared with deterministic approach. 相似文献
58.
59.
科技期刊编辑专业化和学者化是保证期刊学术质量的关键 总被引:1,自引:0,他引:1
一般科技期刊刊载的论文内容都具有很强的专业性,这就要求科技期刊编辑必须具有丰富的专业知识和较高的学术水平才能胜任编辑工作.从编辑过程的选题组稿、论文初审、选择审稿专家和编辑加工四个方面对此进行了阐述,指出了提高科技期刊编辑的相关专业知识和学术水平的措施. 相似文献
60.
ABSTRACT: In a screening of South African indigenous food plants for antioxidant activity by testing for inhibition of lipid peroxidation, the "potherbs" Amaranthus sp., Sisymbrium thellungii , and Urtica dioica had very high activity. This activity was greatest in the boiled extract of Amaranthus sp. and the boilet and aqueous extracts of Sisymbrium thellungii and Urtica dioica. The activity in the aqueous extract of Nasturtium aquatica was lost by boiling. High activity was also obtained with the teas Galium aparine and Aspalathus linearis (Rooibos) and with the tuber Colocasia esculenta. 相似文献