全文获取类型
| 收费全文 | 2766篇 |
| 免费 | 115篇 |
| 国内免费 | 31篇 |
专业分类
| 电工技术 | 79篇 |
| 综合类 | 21篇 |
| 化学工业 | 893篇 |
| 金属工艺 | 75篇 |
| 机械仪表 | 81篇 |
| 建筑科学 | 93篇 |
| 矿业工程 | 6篇 |
| 能源动力 | 141篇 |
| 轻工业 | 254篇 |
| 水利工程 | 54篇 |
| 石油天然气 | 52篇 |
| 武器工业 | 5篇 |
| 无线电 | 219篇 |
| 一般工业技术 | 397篇 |
| 冶金工业 | 96篇 |
| 原子能技术 | 9篇 |
| 自动化技术 | 437篇 |
出版年
| 2025年 | 1篇 |
| 2024年 | 57篇 |
| 2023年 | 53篇 |
| 2022年 | 74篇 |
| 2021年 | 202篇 |
| 2020年 | 158篇 |
| 2019年 | 213篇 |
| 2018年 | 238篇 |
| 2017年 | 225篇 |
| 2016年 | 197篇 |
| 2015年 | 113篇 |
| 2014年 | 200篇 |
| 2013年 | 277篇 |
| 2012年 | 195篇 |
| 2011年 | 211篇 |
| 2010年 | 114篇 |
| 2009年 | 109篇 |
| 2008年 | 69篇 |
| 2007年 | 46篇 |
| 2006年 | 47篇 |
| 2005年 | 19篇 |
| 2004年 | 11篇 |
| 2003年 | 15篇 |
| 2002年 | 9篇 |
| 2001年 | 7篇 |
| 2000年 | 5篇 |
| 1999年 | 6篇 |
| 1998年 | 7篇 |
| 1997年 | 2篇 |
| 1996年 | 7篇 |
| 1995年 | 1篇 |
| 1994年 | 2篇 |
| 1993年 | 2篇 |
| 1992年 | 1篇 |
| 1991年 | 3篇 |
| 1990年 | 4篇 |
| 1987年 | 1篇 |
| 1985年 | 1篇 |
| 1984年 | 2篇 |
| 1983年 | 3篇 |
| 1982年 | 2篇 |
| 1981年 | 1篇 |
| 1976年 | 1篇 |
| 1975年 | 1篇 |
排序方式： 共有2912条查询结果，搜索用时 15 毫秒
961.
Sepide Lotfi Khaled Abdelghany Hossein Hashemi 《Computer-Aided Civil and Infrastructure Engineering》2019,34(1):21-37
This article presents a modeling framework for the operations of on‐demand mobility services (ODMS) in urban areas. The framework provides the capabilities to analyze ODMS operations while representing emerging services such as ridesharing and transfer. The problem is formulated as a mixed integer program and an efficient decomposition‐based methodology is developed for its solution. The methodology adopts a modified version of the column generation algorithm, which implements iterative decomposition and network augmentation techniques to allow studying networks of moderate size. The results of a set of experiments considering grid and real‐world networks are presented. The results show that increasing the number of passengers willing to rideshare and/or transfer improves the overall performance of ODMS as it increases number of served passengers and associated profit and reduces the number of used vehicles. Although presented as an offline planning tool, the methodology could be adopted for real‐time applications as adequate computational resources become available. 相似文献
962.
Successful public open spaces are comfortable arenas where people of different backgrounds, genders and ethnicities benefit from miscellaneous opportunities. This paper seeks to determine the components of a successful public open space. First, a self-administered questionnaire survey identifies the users’ evaluations. Second, structured interviews explore the experts’ opinions about the relevant issues. The results show that social success is the most important factor in making successful public open spaces, while the physical attributes play the least significant role in such spaces. The paper presents a series of pragmatic suggestions that assist urban designers, landscape architects, architects, policy-makers and urban planners in creating lively communities in city centres, which contributes to the social sustainability of cities. 相似文献
963.
964.
965.
966.
967.
Saeid Ebrahimi Hossein A. Dabbagh 《International Journal of Food Science & Technology》2019,54(9):2770-2779
L-Ascorbic acid (AA) is an essential component for organisms and is responsible for various functions in the human body. Its structure is in a way that suffering significant structural changes during storage. Herein, the stability of L-ascorbic acid aqueous solution at various thermal (25 and 90 °C ± 2) and atmospheric oxygen or argon was monitored by optical rotation changes as a function of time intervals. Under oxygen, specific optical rotation [α] of the solution was decreased from + 22.0 to + 2.0 after 32 days and under argon + 11.5 after 9 months at 25 °C. The loss of [α] increased at 90 °C under both oxygen and argon atmospheres. Subsequently, the obtained reaction mixtures were evaporated to dryness and analysed by FT-IR, 1H-NMR and GC-MS techniques. Results of these analyses indicate that AA was decomposed to a complex mixture of reaction products. 相似文献
968.
Mohammadali Hajizadeh Hossein Ebrahimnezhad 《Computer Animation and Virtual Worlds》2016,27(6):556-576
Efficient compression techniques are required for animated mesh sequences with fixed connectivity and time‐varying geometry. In this paper, we propose a key‐frame‐based technique for three‐dimensional dynamic mesh compression. First, key‐frames are extracted from the animated sequence. Extracted key‐frames are then linearly combined using blending weights to predict the vertex locations of the other frames. These blending weights play a key role in the proposed algorithm because the prediction performance and the required number of key‐frames greatly depend on these weights. We present a novel method in order to compute the optimum blending weight that makes it possible to predict location of the vertices of the non‐key frames with the minimum number of key‐frames. The residual prediction errors are finally quantized and encoded using Huffman coding and another heuristic method. Experimental results on different test sequences with various sizes, topologies, and geometries demonstrate the privileged performance of the proposed method compared with the previous techniques. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
969.
Seyed Mahdi Abtahi Seyed Hossein Sadati Hassan Salarieh 《Asian journal of control》2016,18(5):1845-1855
Quasi‐periodic and chaotic behavior, along with the control of chaos for a Gyrostat satellite (GS), is investigated in this work. The quaternion‐based dynamical model of the GS is first derived, and then the influences of the reaction wheels in the GS structure, under the gravity gradient perturbation that causes a route to chaos through quasi‐periodicity mechanism, is investigated. For the suppression of chaos in the system, a chaos control system with the quaternion feedback is designed for the GS based on the extension of the Ott‐Grebogi‐Yorke (OGY) method using the linearization of the Poincaré map. In the extended OGY controller, the Poincaré map is estimated using the Least Square Support Vector Machine (LSSVM) technique. After linearization of the Poincaré map, the Discrete‐time Linear Quadratic Regulator (DLQR) is applied on the linearized Poincaré map, making the DLQR‐OGY controller for chaos. The DLQR‐OGY control system stabilizes the orbits to the fixed points providing a small control input signal, which leads to a decrease in the control effort and energy consumption in the GS system. 相似文献
970.
Mohsen Zare Michel Croq Farhad Hossein‐Arabi Rene Brunet Yves Roquelaure 《人机工程学与制造业中的人性因素》2016,26(2):205-223
Competition is an ongoing challenge confronting industrial corporations, particularly automobile manufacturing. Striving to improve product quality and productivity, automotive industries have used different quality management approaches, such as reduced variability, total quality management, and lean management, over recent years. Furthermore, incorporating proactive ergonomics such as physical and organizational ergonomics and psychosocial factors into the structure of a company is considered to be a support for productivity and quality. Several studies have shown the effects of ergonomics on better quality. Application of both quality management approaches and ergonomics in an integrated manner in the manufacturing production system is emphasized because they are similar concepts with the same objectives, that is, to improve efficiency. In this study, a comprehensive review was undertaken and 25 studies were reviewed in order to define how integration of an ergonomic approach in the manufacturing production system can reduce defects and improve quality in the production process. 相似文献