全文获取类型
收费全文 | 319篇 |
免费 | 8篇 |
国内免费 | 40篇 |
专业分类
电工技术 | 11篇 |
综合类 | 7篇 |
化学工业 | 21篇 |
金属工艺 | 6篇 |
机械仪表 | 24篇 |
建筑科学 | 6篇 |
能源动力 | 2篇 |
轻工业 | 6篇 |
石油天然气 | 6篇 |
无线电 | 9篇 |
一般工业技术 | 15篇 |
冶金工业 | 6篇 |
原子能技术 | 56篇 |
自动化技术 | 192篇 |
出版年
2023年 | 1篇 |
2021年 | 6篇 |
2020年 | 2篇 |
2019年 | 4篇 |
2018年 | 2篇 |
2017年 | 5篇 |
2016年 | 10篇 |
2015年 | 6篇 |
2014年 | 6篇 |
2013年 | 18篇 |
2012年 | 11篇 |
2011年 | 21篇 |
2010年 | 10篇 |
2009年 | 8篇 |
2008年 | 9篇 |
2007年 | 12篇 |
2006年 | 11篇 |
2005年 | 7篇 |
2004年 | 5篇 |
2003年 | 21篇 |
2002年 | 40篇 |
2001年 | 43篇 |
2000年 | 42篇 |
1999年 | 37篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1981年 | 2篇 |
排序方式: 共有367条查询结果,搜索用时 406 毫秒
21.
近年来,用户对企业的效益和效率要求进一步提高,已不再满足于装置的自动化水平的提高,而是把整个工厂(Plant)甚至整个企业集团作为一个可控、健康的有机体来运行,目标是构建一个具备系统性、全面性、实时性和准确性的现代化工厂。流程控制的自动化、仪器仪表使用及维护的智能化、企业管理的信息化等都已成为现代化工厂的标志,随着DCS系统、MES企业管理软件、资产管理软件、ERP等技术的快速发展,为构建现代化工厂提供了坚实的基础。以PlantWeb工厂管理网为基础,通过对其特点、结构及核心应用的详细介绍,阐明了企业自动化系统体系在构建智能化工厂的设计与实现过程,通过该工厂的成功实施进一步说明PlantWeb工厂管控网在智能化工厂建造的优势,为其他工厂的现代化建造或改造提供思路和借鉴。 相似文献
22.
介绍了一种以HART通讯协议为基础的计量监控系统的设计方案,对该系统软件和硬件的构成、数据的采集与通讯和操作界面作了详细介绍,重点阐述了如何利用AMS设备管理软件、OPC通讯技术和iFIX工控组态软件,实现计量数据的采集、上传、统计及显示。 相似文献
23.
24.
In the present paper a new numerical method for the Boltzmann equation is developed. The gain part of the collision integral
is written in a form which allows its numerical computation on the uniform grid to be carried out efficiently. The amount
of numerical work is shown to be of the order O(n
6log(n)) for the most general model of interaction and of the order O(n
6) for the Variable Hard Spheres (VHS) interaction model, while the formal accuracy is of the order O(n
−2). Here n denotes the number of discretisation points in one direction of the velocity space. Some numerical examples for Maxwell pseudo-molecules
and for the hard spheres model illustrate the accuracy and the efficiency of the method in comparison with DSMC computations
in the spatially homogeneous case.
Received June 18, 2002; revised August 23, 2002 Published online: October 24, 2002 相似文献
25.
A general discussion of the including approximation of a curve by a fat arc is given followed by an algorithm for constructing an including fat arc for a parametric Bézier curve. An example of applying the algorithm is given. The results for a fat arc are then used to develop an including approximation for a curve segment using a fat biarc. An algorithm for a fat biarc including approximation is provided followed by examples of Bézier curves being included by a fat biarc. 相似文献
26.
The paper deals with Nitsche type mortaring as a finite element method (FEM) for treating non-matching meshes of triangles
at the interface of some domain decomposition. The approach is applied to the Poisson equation with Dirichlet boundary conditions
(as a model problem) under the aspect that the interface passes re-entrant corners of the domain. For such problems and non-matching
meshes with and without local refinement near the re-entrant corner, some properties of the finite element scheme and error
estimates are proved. They show that appropriate mesh grading yields convergence rates as known for the classical FEM in presence
of regular solutions. Finally, a numerical example illustrates the approach and the theoretical results.
Received July 5, 2001; revised February 5, 2002 Published online April 25, 2002 相似文献
27.
Gerd Kunert 《Computing》2002,69(3):265-272
This paper considers a singularly perturbed reaction diffusion problem. It is investigated whether adaptive approaches are
successful to design robust solution procedures. A key ingredient is the a posteriori error estimator. Since robust and mathematically analysed error estimation is possible in the energy norm, the focus is on this choice of norm and its implications. The numerical performance for several model problems confirms
that the proposed adaptive algorithm (in conjunction with an energy norm error estimator) produces optimal results. Hence
the energy norm is suitable for the purpose considered here. The investigations also provide valuable justification for forthcoming
research.
Received October 25, 2001; revised July 12, 2002 Published online: October 24, 2002 相似文献
28.
A cascadic multigrid (CMG) method for elliptic problems with strong material jumps is proposed and analyzed. Non–matching
grids at interfaces between subdomains are allowed and treated by mortar elements. The arising saddle point problems are solved
by a subspace confined conjugate gradient method as smoother for the CMG. Details of algorithmic realization including adaptivity
are elaborated. Numerical results illustrate the efficiency of the new subspace CMG algorithm.
Received December 14, 2001; revised September 2, 2002 Published online: November 18, 2002 相似文献
29.
北京大学6MV串列静电加速器上建成4条束流输运线,加速^1H,^12C,^16O,^19F,^35Cl,^79Br等离子,并开展物理实验研究。首次利用D(^12C,p)^13C核反应建立起高灵敏度的氘分析法;利用共振核反应^1H(^19F,αγ)^16O分析材料中氢的深度分布;用重离子背散射分析超导材料YBa2Cu3O7-x;用35MeV^35Cl和45MeV^79Br的弹性前冲分析不同材料中的轻 相似文献
30.
AbstractSpeech enhancement is an interesting research area that aims at improving the quality and intelligibility of the speech that is affected by the additive noises, such as airport noise, train noise, restaurant noise, and so on. The presence of these background noises degrades the comfort of listening of the end user. This article proposes a speech enhancement method that uses a novel feature extraction which removes the noise spectrum from the noisy speech signal using a novel fractional delta-AMS (amplitude modulation spectrogram) feature extraction and the D-matrix feature extraction method. The fractional delta-AMS feature extraction strategy is the modification of the delta-AMS with the fractional calculus that increases the sharpness of the feature extraction. The extracted features from the frames are used to determine the optimal mask of all the frames of the noisy speech signal and the mask is employed for training the deep belief neural networks (DBN). The two metrics root mean square error (RMSE) and perceptual evaluation of speech quality (PESQ) are used to evaluate the method. The proposed method yields a better value of PESQ at all level of noise and RMSE decreases with increased noise level. 相似文献