全文获取类型
收费全文 | 1927篇 |
免费 | 87篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 11篇 |
综合类 | 26篇 |
化学工业 | 465篇 |
金属工艺 | 55篇 |
机械仪表 | 63篇 |
建筑科学 | 58篇 |
矿业工程 | 2篇 |
能源动力 | 110篇 |
轻工业 | 205篇 |
水利工程 | 13篇 |
石油天然气 | 13篇 |
无线电 | 120篇 |
一般工业技术 | 339篇 |
冶金工业 | 267篇 |
原子能技术 | 16篇 |
自动化技术 | 254篇 |
出版年
2024年 | 6篇 |
2023年 | 28篇 |
2022年 | 23篇 |
2021年 | 58篇 |
2020年 | 55篇 |
2019年 | 40篇 |
2018年 | 68篇 |
2017年 | 81篇 |
2016年 | 73篇 |
2015年 | 53篇 |
2014年 | 85篇 |
2013年 | 189篇 |
2012年 | 106篇 |
2011年 | 99篇 |
2010年 | 88篇 |
2009年 | 89篇 |
2008年 | 89篇 |
2007年 | 77篇 |
2006年 | 60篇 |
2005年 | 47篇 |
2004年 | 53篇 |
2003年 | 56篇 |
2002年 | 27篇 |
2001年 | 24篇 |
2000年 | 16篇 |
1999年 | 33篇 |
1998年 | 101篇 |
1997年 | 47篇 |
1996年 | 49篇 |
1995年 | 25篇 |
1994年 | 14篇 |
1993年 | 12篇 |
1992年 | 8篇 |
1991年 | 7篇 |
1990年 | 7篇 |
1989年 | 8篇 |
1988年 | 10篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 7篇 |
1983年 | 4篇 |
1982年 | 8篇 |
1981年 | 5篇 |
1980年 | 10篇 |
1979年 | 7篇 |
1977年 | 8篇 |
1976年 | 19篇 |
1974年 | 4篇 |
1973年 | 5篇 |
1972年 | 3篇 |
排序方式: 共有2017条查询结果,搜索用时 15 毫秒
181.
182.
Ayenur Gürgen Elif Topalolu Derya Ustamer Sibel Yldz Nurgül Ay 《Color research and application》2019,44(5):824-833
In this study, the colorimetric parameters (L*, a*, b*) and mass loss of heat‐treated bamboo were investigated, and the obtained results were modeled by using two methods: multiple linear regression (MLR) and artificial neural network (ANN). First, bamboo samples were exposed to heat treatment at different temperatures (110°C, 140°C, 170°C, and 200°C) and durations (15, 30, 45, 60, 75, 90, and 115 minutes) in a laboratory oven. Then, the colorimetric parameters (L*, a*, b*) and mass loss of each sample were measured after each period of heat treatment. All data were modeled by using two methods separately for each parameter and the performances of these proposed methods were compared. It was found that color change and mass loss increased with increasing temperature and duration of heat treatment. Mean absolute percentage error (MAPE) values of all obtained MLR ranged from 0.64% to 10.63%, while the all MAPE values of ANN were found to be lower than 1.5%. Based on these results, it can be said that MLR and ANN could be used to evaluate the changes on the selected properties of heat‐treated bamboo samples. On the other hand, it should be emphasized that the ANN gave more accurate results than the MLR method because of its learning capability. 相似文献
183.
Powder coatings formed by flame spraying are being used in industrial applications. The resistance of plastics and their composite materials to chemicals, solvents, and atmospheric conditions and their high impact strength even at low service temperatures increase the importance of plastic and plastic‐based coatings. In this study, an ethylene vinyl alcohol copolymer powder was coated via flame spraying with gases of oxygen and acetylene. The bond strengths and microstructures of the coatings were determined with tensile testing, scanning electron microscopy, and Fourier transform infrared. The bond strengths of the coatings were determined according to ASTM C 633. Oxidizing, carburizing, and neutral flames were used. The bond strengths were lower for the oxidizing and carburizing coatings than for the neutral flame coatings. The results indicated that during the flame‐spraying process, the composition, gas, spraying distance, and coating thickness were important factors in the coating bond strength. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1357–1364, 2004 相似文献
184.
185.
一株丝状真菌发酵法产红色素培养基的研究 总被引:1,自引:0,他引:1
研究了一株丝状真菌Miug-2.7发酵法生产红色素的液体培养基最佳组分,以及液体发酵培养基最佳配方.结果表明,本试验范围内最佳质量配比是淀粉3%,蛋白胨1.0%,诱导物1%,起始pH7.5. 相似文献
186.
王为 《湖北工业大学学报》2003,18(4):23-26
介绍了先进制造技术的发展历程及其系统体系,重点阐述了现代制造系统工程设计技术的重要地位,并对我国加入世贸组织后制造业前景作了简要展望. 相似文献
187.
基于快速原型制造技术的产品开发 总被引:2,自引:0,他引:2
介绍了适应市场的快速响应设计技术的内容,关键技术和具体实施策略,快速响应设计在企业竞争中的作用.同时说明了快速原型制造技术在快速制造中的作用. 相似文献
188.
S. Besset L. Jézéquel 《International journal for numerical methods in engineering》2010,82(12):1560-1573
This paper deals with modal criteria allowing optimization of structures through active structural acoustic control (ASAC) based on the independent modal strategy control (IMSC). The aim of the paper is to propose efficient criteria allowing to process optimization of structures by determining the most important modes to control considering only the location of the excitation on the structure. A generalized modal synthesis is used to study the coupled fluid–structure system. Modal criteria are proposed in order to determine the best choice for the controlled modes used in IMSC method. The way the ASAC will be applied is not discussed in the paper. Numerical simulations are computed to show the efficiency of the method, considering a simple vibroacoustic structure. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
189.
190.
Muhammad Haûdz Fazli bin Md Fauadi Saifudin Haûz Yahaya Tomohiro Murata 《IEEJ Transactions on Electrical and Electronic Engineering》2013,8(4):371-379
The need to have an efficient transportation system has attracted worldwide attention. Although there is increasing demand to implement distributed control system for industrial applications, there is still an unexplored potential of deploying distributed transportation system. This paper focuses on dynamic assignment of transportation requests to a fleet of vehicles in real time. We introduce an improved combinatorial auction methodology to accommodate the distributed task assignment procedure. Based on a multiagent architecture, each vehicle is represented by an intelligent agent that bids for task and plans its own schedule. On the other hand, the auctioneer has the objective of minimizing transportation tardiness. An automated guided vehicle (AGV) has been selected as the case study, and numerical experiments have been carried out. The result obtained shows that the improved task assignment approach is able to produce performance competitive to a conventional task assignment. © 2013 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献