全文获取类型
收费全文 | 24775篇 |
免费 | 2610篇 |
国内免费 | 1766篇 |
专业分类
电工技术 | 2116篇 |
技术理论 | 7篇 |
综合类 | 3387篇 |
化学工业 | 581篇 |
金属工艺 | 218篇 |
机械仪表 | 1140篇 |
建筑科学 | 8329篇 |
矿业工程 | 351篇 |
能源动力 | 334篇 |
轻工业 | 379篇 |
水利工程 | 202篇 |
石油天然气 | 445篇 |
武器工业 | 234篇 |
无线电 | 2556篇 |
一般工业技术 | 1779篇 |
冶金工业 | 1173篇 |
原子能技术 | 163篇 |
自动化技术 | 5757篇 |
出版年
2024年 | 125篇 |
2023年 | 325篇 |
2022年 | 602篇 |
2021年 | 656篇 |
2020年 | 690篇 |
2019年 | 594篇 |
2018年 | 573篇 |
2017年 | 701篇 |
2016年 | 817篇 |
2015年 | 922篇 |
2014年 | 1718篇 |
2013年 | 1394篇 |
2012年 | 1849篇 |
2011年 | 2080篇 |
2010年 | 1816篇 |
2009年 | 1796篇 |
2008年 | 1747篇 |
2007年 | 1890篇 |
2006年 | 1650篇 |
2005年 | 1311篇 |
2004年 | 1057篇 |
2003年 | 878篇 |
2002年 | 716篇 |
2001年 | 625篇 |
2000年 | 512篇 |
1999年 | 410篇 |
1998年 | 296篇 |
1997年 | 217篇 |
1996年 | 193篇 |
1995年 | 183篇 |
1994年 | 146篇 |
1993年 | 109篇 |
1992年 | 119篇 |
1991年 | 59篇 |
1990年 | 53篇 |
1989年 | 57篇 |
1988年 | 46篇 |
1987年 | 26篇 |
1986年 | 24篇 |
1985年 | 16篇 |
1984年 | 11篇 |
1983年 | 8篇 |
1982年 | 12篇 |
1981年 | 14篇 |
1980年 | 8篇 |
1979年 | 8篇 |
1964年 | 10篇 |
1960年 | 7篇 |
1959年 | 10篇 |
1956年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Carels Robert A.; Cacciapaglia Holly; Pérez-Benítez Carlos I.; Douglass Olivia; Christie Samantha; O'Brien William H. 《Canadian Metallurgical Quarterly》2003,71(4):753
Reports an error in the original article by R. A. Carels et al (Journal of Consulting & Clinical Psychology, 2003[Jun], Vol 71[3], 613-618). On page 615, Lines 18, 20, 22, of Table 1, the data in the rows that read "Tachycardia in min per hr," "Repetitive PVCs per hr," and "PVCs per hr" are incorrectly reported in the n and % columns. They should have been reported in the M and SD columns. The corrected table is provided. (The following abstract of this article originally appeared in record 2003-00756-023.) Ventricular arrhythmia exhibits considerable within-subject variability that cannot be attributed to clinical status alone. This investigation examined the extent to which cardiac arrhythmia was associated with psychological and physical factors assessed during the hour preceding arrhythmic or nonarrhythmic activity. Approximately twice hourly, 46 patients randomly completed a diary assessing mood and physical symptoms during 24-hr electrocardiographic monitoring. Greater negative emotion was associated with increased arrhythmia. Additionally, greater negative emotion was significantly associated with increased arrhythmia among participants in a low left ventricular ejection fraction group (LVEF). However, this relationship between negative emotion and arrhythmia was not... (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
22.
Generalized null space uncorrelated Fisher discriminant analysis for linear dimensionality reduction
We propose a generalized null space uncorrelated Fisher discriminant analysis (GNUFDA) technique integrating the uncorrelated discriminant analysis and weighted pairwise Fisher criterion. The GNUFDA can effectively deal with the small sample-size problem and perform satisfactorily when the dimensionality of the null space decreases with increase in the number of training samples per class and/or classes, C. The proposed GNUFDA can extract at most C-1 optimal uncorrelated discriminative vectors without being influenced by the null-space dimensionality. 相似文献
23.
Yvon Maday Frédéric Magoulès 《Computer Methods in Applied Mechanics and Engineering》2007,196(8):1541-1553
In this paper an original variant of the Schwarz domain decomposition method is introduced for heterogeneous media. This method uses new optimized interface conditions specially designed to take into account the heterogeneity between the sub-domains on each sides of the interfaces. Numerical experiments illustrate the dependency of the proposed method with respect to several parameters, and confirm the robustness and efficiency of this method based on such optimized interface conditions. Several mesh partitions taking into account multiple cross points are considered in these experiments. 相似文献
24.
Markovian and semi-Markovian random processes are used to analyze the problem of optimal search for signals in a multichannel
communication system with arbitrarily distributed random outputs. The search efficiency factor is found in explicit form based
on state space merging, and a mathematical programming problem is set up to find a numerical suboptimal solution.
__________
Translated from Kibernetika i Sistemnyi Analiz, No. 3, pp. 144–150, May–June 2007. 相似文献
25.
CIE TC8‐01 has adopted a new color appearance model: CIECAM021 replaces the CIECAM97s.2 The new model consists of a number of refinements and simplifications of the CIECAM97s color appearance model. This article describes further tests to the robustness of the forward and reverse modes. © 2005 Wiley Periodicals, Inc. Col Res Appl, 30, 99–106, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20087 相似文献
26.
Automated techniques for satellite imagery navigation and co-location are especially required for environmental monitoring activities intensively using satellite data. In this work are presented the results obtained after 2 years of operational use of the Subpixel Automatic Navigation of AVHRR (SANA) scheme. An automatic method for accuracy assessment of satellite navigation techniques, which permits a preliminary evaluation of their performances, dealing with a large collection of test images is also proposed. The navigation accuracy assessment, performed by using a selection of small islands as reference points, is discussed.Results achieved over more than 400 Advanced Very-High-Resolution Radiometer (AVHRR) scenes confirm that the SANA scheme is a very accurate one (computed mean navigation error is generally about one AVHRR pixel). Furthermore, because of its high processing speed, it can be considered a suitable tool for intensive satellite data processing in multitemporal analyses, especially required for environmental studies as well as for operational monitoring purposes. 相似文献
27.
Aleksej G. Voloboj 《Computer Graphics Forum》1993,12(5):289-296
The paper describes the colour approximation problem and the method of dynamic palette construction is suggested for its solution. The method uses the graphic display palette based on the computed true colour of the individual picture. Some aspects of human colour perception are considered. Two metrics in colour space are introduced to estimate closeness of the suggested colour approximation. The method was applied to visualize 3D scenes generated by ray tracing. 相似文献
28.
张丹凤 《数码设计:surface》2012,(6):126-127
本文从产品设计在情感化产品中的造型语言入手,从本能情感、行为情感和反思情感三方面具体阐述了情感化的造型语言在现代产品设计中的体现形式,旨在让人们对于产品的造型语言有更加深入清晰的认识,更好的实现工业产品的人性化设计。 相似文献
29.
宋晓东 《数码设计:surface》2012,(6):77-79
在消费社会的背景下,消费文化观念获得重要突破——"消费是一种体验",消费文化催生了现代商业空间环境的体验功能。本文归纳了在消费文化影响下体验型商业空间环境的特质,以案例为基础讨论了各类体验型商业空间环境的特点,并在设计理念的层面上对情境体验空间、主题体验空间、超现实体验空间的营造思路做出了探索。 相似文献
30.
Cyber–physical systems are becoming increasingly complex. In these advanced systems, the different engineering domains involved in the design process become more and more intertwined. Therefore, a traditional (sequential) design process becomes inefficient in finding good design options. Instead, an integrated approach is needed where parameters in multiple different engineering domains can be chosen, evaluated, and optimized to achieve a good overall solution. However, in such an approach, the combined design space becomes vast. As such, methods are needed to mitigate this problem.In this paper, we show a method for systematically capturing and updating domain knowledge in the context of a co-design process involving different engineering domains, i.e. control and embedded. We rely on ontologies to reason about the relationships between parameters in the different domains. This allows us to derive a stepwise design space exploration workflow where this domain knowledge is used to quickly reduce the design space to a subset of likely good candidates. We illustrate our approach by applying it to the design space exploration process for an advanced electric motor control system and its deployment on embedded hardware. 相似文献