全文获取类型
收费全文 | 670篇 |
免费 | 87篇 |
国内免费 | 79篇 |
专业分类
电工技术 | 19篇 |
综合类 | 38篇 |
化学工业 | 38篇 |
金属工艺 | 22篇 |
机械仪表 | 42篇 |
建筑科学 | 14篇 |
矿业工程 | 10篇 |
能源动力 | 37篇 |
轻工业 | 9篇 |
水利工程 | 4篇 |
石油天然气 | 15篇 |
武器工业 | 4篇 |
无线电 | 202篇 |
一般工业技术 | 61篇 |
冶金工业 | 5篇 |
原子能技术 | 11篇 |
自动化技术 | 305篇 |
出版年
2023年 | 3篇 |
2022年 | 16篇 |
2021年 | 15篇 |
2020年 | 17篇 |
2019年 | 13篇 |
2018年 | 20篇 |
2017年 | 19篇 |
2016年 | 33篇 |
2015年 | 33篇 |
2014年 | 54篇 |
2013年 | 69篇 |
2012年 | 51篇 |
2011年 | 51篇 |
2010年 | 32篇 |
2009年 | 39篇 |
2008年 | 40篇 |
2007年 | 37篇 |
2006年 | 32篇 |
2005年 | 32篇 |
2004年 | 28篇 |
2003年 | 18篇 |
2002年 | 19篇 |
2001年 | 9篇 |
2000年 | 12篇 |
1999年 | 15篇 |
1998年 | 15篇 |
1997年 | 17篇 |
1996年 | 19篇 |
1995年 | 19篇 |
1994年 | 9篇 |
1993年 | 10篇 |
1992年 | 7篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 5篇 |
1988年 | 9篇 |
1987年 | 4篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1980年 | 1篇 |
排序方式: 共有836条查询结果,搜索用时 15 毫秒
1.
2.
Yahia Lebbah 《Artificial Intelligence》2002,139(1):109-132
Search algorithms for solving Numeric CSPs (Constraint Satisfaction Problems) make an extensive use of filtering techniques. In this paper1 we show how those filtering techniques can be accelerated by discovering and exploiting some regularities during the filtering process. Two kinds of regularities are discussed, cyclic phenomena in the propagation queue and numeric regularities of the domains of the variables. We also present in this paper an attempt to unify numeric CSPs solving methods from two distinct communities, that of CSP in artificial intelligence, and that of interval analysis. 相似文献
3.
It is shown that the well known two-pass sequential local transformation algorithm for computing a distance transformation in rectangular domains may fail in some convex integer domains, but that a four-pass algorithm is sufficient in all two-dimensional convex domains. For non-convex domains the number of passes necessary is shown to be generally greater. Two propagation algorithms for computing the distance transformation are described and shown theoretically and experimentally to be computationally more efficient than the sequential local transformation algorithm in non-convex domains of complex shape. The relationship of the distance transformation in non-convex domains to some more general transformations is explored. 相似文献
4.
传播介质特性对爆破震动信号分析中小波包时频特征的影响 总被引:1,自引:1,他引:0
传播介质是指爆破震动赖以向外传播的地层介质 ,其基本特征是影响爆破震动时频分布的主要因素之一。当传播介质中有爆破震动通过时 ,其动态响应将会因其原地结构的不同而在响应持续时间、频谱、响应的衰减等特征方面均有较大差异。本文利用岩体 (岩土混合体 )基本质量指标BQ值以及完整性系数Kv 来量化传播介质特性。通过对不同岩层地质条件下产生的爆破震动进行小波包分析 ,探讨了传播介质特性量化参数与爆破震动时频分布之间的关系。研究中发现 ,传播介质特性对单段波形小波包细节信号的主振频带分布、峰值质点振速及衰减阻尼比等时频特征参数均有较大影响 ,其中主振频带分布范围随着传播介质的完整性系数Kv 值减小而增大 ,优势频率值随完整性系数Kv 值减小而增加 ,而峰值质点振速及衰减阻尼比与完整性系数Kv 值之间的规律性不强 相似文献
5.
In this letter, an integrated application of the prediction for radio wave propagation with the Geographic Information System (GIS) is presented and a real prediction system based on GIS is implemented. 相似文献
6.
Jrme Bachmann Jean marc Linares Jean Michel Sprauel Pierre Bourdet 《Precision Engineering》2004,28(1):342-88
The authorities of the standards organization International Organization of Standardization (ISO) advocate mastering any uncertainties in all parts of the industrialization process. In the three-dimensional (3D) measurement process, uncertainty is usually obtained at the end of a battery of tests. It is defined as a whole because it includes several types of errors, known systematic components, unknown systematic components and random components. Automated calculations of uncertainty can be made based on statistics. This method is based on statistical concepts, which are in accordance with “The Guide to the expression of the uncertainty in measurement” (GUM). It also enables us to generate uncertainties on the verification of ISO specifications (or specs in the ISO directives). In the course of this article, a usage will be presented that takes the knowledge of uncertainties into account: this usage will help the operator to take a decision on the conformance of a mechanical part in reference to its conformance to geometric tolerance. 相似文献
7.
卡通是大众所钟爱的一种艺术形式,在这样一个文化多元而开放的时代,人们推崇的卡通形象无论从造型、个性与角色背景方面都呈现出显著的"草根化"趋势,而这种趋势已成为推动卡通文化流动和发展的原动力之一。 相似文献
8.
Tae?Joon?Chung Min?Chan?Kim Chang?Kyun?ChoiEmail author 《Korean Journal of Chemical Engineering》2004,21(1):41-47
The temporal development of thermal disturbances in the fluid layer heated isothermally from below is investigated, based
on propagation theory. This theory is examined by using scaling. To examine the behavior of thermal instability the mean-field
approximation is employed and resulting equations are solved by Galerkin method. The stability criteria to mark the onset
of convective instability are newly suggested as the intersection point of the growth rate of averaged temperature with that
of its fluctuation. The resulting critical time is close to that derived from propagation theory. By considering the nonlinear
effects, the characteristic times to represent the detection time of manifest convection and also to exhibit the minimum Nusselt
number are discussed. 相似文献
9.
We present a data‐driven method for automatically recoloring a photo to enhance its appearance or change a viewer's emotional response to it. A compact representation called a RegionNet summarizes color and geometric features of image regions, and geometric relationships between them. Correlations between color property distributions and geometric features of regions are learned from a database of well‐colored photos. A probabilistic factor graph model is used to summarize distributions of color properties and generate an overall probability distribution for color suggestions. Given a new input image, we can generate multiple recolored results which unlike previous automatic results, are both natural and artistic, and compatible with their spatial arrangements. 相似文献
10.