全文获取类型
收费全文 | 569篇 |
免费 | 57篇 |
专业分类
电工技术 | 10篇 |
化学工业 | 128篇 |
金属工艺 | 14篇 |
机械仪表 | 8篇 |
建筑科学 | 17篇 |
能源动力 | 31篇 |
轻工业 | 47篇 |
水利工程 | 10篇 |
无线电 | 45篇 |
一般工业技术 | 151篇 |
冶金工业 | 24篇 |
原子能技术 | 10篇 |
自动化技术 | 131篇 |
出版年
2024年 | 1篇 |
2023年 | 11篇 |
2022年 | 10篇 |
2021年 | 30篇 |
2020年 | 22篇 |
2019年 | 18篇 |
2018年 | 24篇 |
2017年 | 30篇 |
2016年 | 30篇 |
2015年 | 26篇 |
2014年 | 30篇 |
2013年 | 61篇 |
2012年 | 38篇 |
2011年 | 71篇 |
2010年 | 35篇 |
2009年 | 44篇 |
2008年 | 44篇 |
2007年 | 28篇 |
2006年 | 24篇 |
2005年 | 18篇 |
2004年 | 10篇 |
2003年 | 5篇 |
2002年 | 4篇 |
2000年 | 2篇 |
1998年 | 2篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有626条查询结果,搜索用时 31 毫秒
11.
This editorial introduces the special issue of the Elsevier journal, Engineering Application of Artificial Intelligence, on Distributed control of production systems. The current technology in communication and embedded systems allows products and production resources to play a more active role in the production process. This new active capacity will generate major changes in organizations and information systems (e.g., Enterprise Resource Planning (ERP) and Manufacturing Execution Systems (MES)). New approaches are now required for modelling, testing and assessing the features made possible by the decisional and informational capabilities of these new active entities. One among the many possibilities is to use agents and holons, since agent and holon-based approaches assume interaction between intelligent entities to facilitate the emergence of a global behavior. This special issue thus focuses on the possible applications of distributed approaches for the design, evaluation and implementation of new control architectures for production systems. Both fundamental and applied research papers are presented. 相似文献
12.
Damien Sulla-Menashe Mark A. Friedl Olga N. Krankina Alessandro Baccini Curtis E. Woodcock Adam Sibley Guoqing Sun Viacheslav Kharuk Vladimir Elsakov 《Remote sensing of environment》2011,115(2):392-403
The Northern Eurasian land mass encompasses a diverse array of land cover types including tundra, boreal forest, wetlands, semi-arid steppe, and agricultural land use. Despite the well-established importance of Northern Eurasia in the global carbon and climate system, the distribution and properties of land cover in this region are not well characterized. To address this knowledge and data gap, a hierarchical mapping approach was developed that encompasses the study area for the Northern Eurasia Earth System Partnership Initiative (NEESPI). The Northern Eurasia Land Cover (NELC) database developed in this study follows the FAO-Land Cover Classification System and provides nested groupings of land cover characteristics, with separate layers for land use, wetlands, and tundra. The database implementation is substantially different from other large-scale land cover datasets that provide maps based on a single set of discrete classes. By providing a database consisting of nested maps and complementary layers, the NELC database provides a flexible framework that allows users to tailor maps to suit their needs. The methods used to create the database combine empirically derived climate–vegetation relationships with results from supervised classifications based on Moderate Resolution Imaging Spectroradiometer (MODIS) data. The hierarchical approach provides an effective framework for integrating climate–vegetation relationships with remote sensing-based classifications, and also allows sources of error to be characterized and attributed to specific levels in the hierarchy. The cross-validated accuracy was 73% for the land cover map and 73% and 91% for the agriculture and wetland classifications, respectively. These results support the use of hierarchical classification and climate–vegetation relationships for mapping land cover at continental scales. 相似文献
13.
14.
15.
16.
Composite materials owe their success to the ability to favour mechanical properties in specific directions whilst minimising the weight of components. Although the composite manufacturing process has been progressively improved, subtle defects such as fibre waviness are still commonplace. Any localised departure of a ply from the desired lay-up direction is known to adversely affect strength. Therefore, manufacturers and end users are interested in detecting defects such as fibre waviness at various stages during prototyping and as part of the manufacturing process. In this paper, an ultrasonic array is used to both image the composite and extract information that characterises the scattering of the interior structure. The scattering information is encoded in the scattering matrix: defined as the far field amplitude of scattered signals from a defect as a function of the incident and scattering angles. A method for extracting the scattering matrix from experimental array data over a spatially localised region is presented. Ultimately this could lead to the ability to map the distribution of scattering behaviour within the composite. The method is demonstrated on composite samples containing various levels of waviness. It is also shown that use of the differences in the scattering matrices can offer the possibility to statistically differentiate wavinesses of different nature and severity. 相似文献
17.
Mohammed A?der Andrée-Anne Martel Joanny Ferracci Damien de Halleux 《Food and Bioprocess Technology》2012,5(8):3051-3065
The main objective of the present project was the purification of brown flaxseed meal from coloring pigments in order to improve its potential use as ingredient in food formulations. Thus, this work was aimed to study the bleaching of non-defatted brown flaxseed meal in dilute hydrogen peroxide solutions. Bleaching was evaluated according to the Hunter L, (a), and (b) color scale as function of the hydrogen peroxide concentration (1%, 2%, and 3% v/v), the meal concentration (2.5%, 5%, and 10% w/w), the bleaching time (10, 20, and 30?min), and the pH (3, 7, and 9). Effect of all the independent variables was significant. The L value was the most significantly affected parameter and increased as the concentration of hydrogen peroxide increased, but decreased as the concentration of flaxseed meal increased. The L value was observed to be higher at pH?9 than at pH?3 and 7. The b value, which represents the yellowness, was significantly increased from 18.70?±?0.01 (control sample) to 35.45?±?0.04 after the meal was treated with a 3% hydrogen peroxide solution at pH?9. Total phenolics content significantly decreased when the meal was treated with 3% (v/v) hydrogen peroxide solution. This concentration yielded the higher L color value (highly bleached meal). 相似文献
18.
19.
Damien Trentesaux Cyrille Pach Abdelghani Bekrar Yves Sallez Thierry Berger Thérèse Bonte Paulo Leitão José Barbosa 《Control Engineering Practice》2013,21(9):1204-1225
Benchmarking is comparing the output of different systems for a given set of input data in order to improve the system’s performance. Faced with the lack of realistic and operational benchmarks that can be used for testing optimization methods and control systems in flexible systems, this paper proposes a benchmark system based on a real production cell. A three-step method is presented: data preparation, experimentation, and reporting. This benchmark allows the evaluation of static optimization performances using traditional operation research tools and the evaluation of control system's robustness faced with unexpected events. 相似文献
20.