全文获取类型
收费全文 | 606篇 |
免费 | 21篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 5篇 |
化学工业 | 116篇 |
金属工艺 | 9篇 |
机械仪表 | 19篇 |
建筑科学 | 28篇 |
能源动力 | 19篇 |
轻工业 | 56篇 |
水利工程 | 10篇 |
石油天然气 | 9篇 |
无线电 | 35篇 |
一般工业技术 | 144篇 |
冶金工业 | 89篇 |
原子能技术 | 2篇 |
自动化技术 | 87篇 |
出版年
2023年 | 9篇 |
2022年 | 19篇 |
2021年 | 17篇 |
2020年 | 16篇 |
2019年 | 23篇 |
2018年 | 20篇 |
2017年 | 9篇 |
2016年 | 26篇 |
2015年 | 20篇 |
2014年 | 28篇 |
2013年 | 39篇 |
2012年 | 34篇 |
2011年 | 44篇 |
2010年 | 39篇 |
2009年 | 25篇 |
2008年 | 21篇 |
2007年 | 26篇 |
2006年 | 26篇 |
2005年 | 26篇 |
2004年 | 11篇 |
2003年 | 17篇 |
2002年 | 15篇 |
2001年 | 10篇 |
2000年 | 9篇 |
1999年 | 11篇 |
1998年 | 6篇 |
1997年 | 2篇 |
1996年 | 6篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1987年 | 2篇 |
1983年 | 3篇 |
1982年 | 6篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 6篇 |
1976年 | 4篇 |
1975年 | 3篇 |
1974年 | 5篇 |
1973年 | 5篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有628条查询结果,搜索用时 15 毫秒
11.
Practices and risks associated with operation of tie-down lashings in the vehicle transport industry
Load restraint systems in automobile transport utilise tie-down lashings placed over the car’s tyres, which are tensioned manually by the operator using a ratchet assembly. This process has been identified as a significant manual handling injury risk. The aim of this study was to gain insight on the current practices associated with tie-down lashings operation, and identify the gaps between current and optimal practice. We approached this with qualitative and quantitative assessments and one numerical simulation to establish: (i) insight into the factors involved in ratcheting; (ii) the required tension to hold the car on the trailer; and (iii) the tension achieved by drivers in practice and associated joint loads. We identified that the method recommended to the drivers was not used in practice. Drivers instead tensioned the straps to the maximum of their capability, leading to over-tensioning and mechanical overload at the shoulder and elbow. We identified the postures and strategies that resulted in the lowest loads on the upper body during ratcheting (using both hands and performing the task with their full body). This research marks the first step towards the development of a training programme aiming at changing practice to reduce injury risks associated with the operation of tie-down lashings in the automobile transport industry.
Practitioner Summary: The study investigated current practice associated with the operation of tie-down lashings through qualitative (interviews) and quantitative (biomechanical analysis) methods. Operators tended to systematically over-tension the lashings and consequently overexert, increasing injury risks. 相似文献
12.
Clean Technologies and Environmental Policy - Industrial wastes can be used as alternative fuel sources for the substitution of fossil fuel if they contain good calorific values. Through... 相似文献
13.
Mcmullen Thomas B. Salamida Dominic P. 《Industry Applications, IEEE Transactions on》1976,(5):527-529
Operation of an elastomeric blade requires the use of a boundary lubricant to remove residual xerographic toner from the photoreceptor efficiently. A radioactive tracer technique was used to study the behaviour of a number of lubricants used in the xerographic process. Both filming and nonfilming type lubricants were investigated using this technique. The results indicated that the lubricant film deposited on the photoreceptor must be in the thickness range of from 1 to 3 molecular layers for acceptable xerographic development and cleaning. Film thickness was shown to be dependent on the class of lubricant, the concentration of lubricant in toner, and the inclusion of a silica compound in the toner. Films are dynamic in nature, continuously being formed and removed during the xerographic process. Parameters affecting the filming mechanism are discussed. 相似文献
14.
15.
16.
17.
Quan-Bao Ma Jürgen Ziegler Bernhard Kaiser Dominic Fertig Wolfram Calvet Eswaran Murugasen Wolfram Jaegermann 《International Journal of Hydrogen Energy》2014
The electrochemical properties of single-crystalline p-type 3C-SiC films on p-Si substrate were investigated as an electrode in H2SO4 aqueous solutions in dark and under white light illumination. The photoelectrochemical (PEC) measurements indicates the p-type 3C-SiC film on p-Si substrate can generate a cathodic photocurrent as a photocathode, which corresponds to hydrogen production, and generate an anodic photocurrent as a photoanode, which corresponds to oxygen evolution. The surface chemical states of the films were investigated by XPS. In order to observe the surface chemical state changes after PEC test, the range of applied potential to the electrode was divided into three zones: −3.6 to 0 V, 0–1.5 V and 1.5–4 V vs. Ag/AgCl. After separated PEC tests in these three areas, XPS shows the surface of the SiC film in the range of −3.6 to 0 V and 0–1.5 V was stable without oxidation except the band bending occurred. But in the range of 1.5–4 V the film surface was oxidized due to anodic oxidation. 相似文献
18.
19.
A number of critiques have been published drawing attention to the gaps in research methods applied to issues surrounding homelessness and service utilisation in Britain. This paper discusses the use of social identity, a theory drawn from the field of applied social psychology, and synthesises it with the pathways model, thereby providing a framework to further explore service utilisation. The synthesised framework was used to predict the uptake of outreach services in a prospective study of 121 homeless people in a major UK city. In general, homeless people's use of intervention services was affected by the extent to which they identified with the support services themselves. The study demonstrates the central role of social identity in understanding service utilisation patterns, and shows the importance of applying fresh techniques to fine-tune our understanding of uptake in the long term. 相似文献
20.
Jingjing Liu Yimin Zhou Grahame E. Faulkner Dominic C. O'Brien Steve Collins 《International Journal of Circuit Theory and Applications》2015,43(7):840-853
The ability to create and direct beams of light means that optical communications potentially offer a large power advantage over RF communications for sensor networks. This paper presents an optically powered receiver front end for wireless optical communications. A complete optical receiver front end including a photodetector, clock and Manchester data recovery circuits has been fabricated using the UMC 180 nm CMOS process. A novel modulation scheme is described that has been devised so that this front end can recover the clock and Manchester data from an optical beam. Experimental results show that the total current consumption of the optical receiver front end is as low as 18.8 nA for a 0.5 V supply when a 1 kbps Manchester data and 8 kHz clock signal are successfully recovered. This means that photodiodes on the same substrate as the front end circuits extract enough power from the communications beam to allow the front end to work at distances of up to 10 m from the transmitter. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献