全文获取类型
收费全文 | 260篇 |
免费 | 7篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 5篇 |
化学工业 | 73篇 |
金属工艺 | 18篇 |
机械仪表 | 15篇 |
建筑科学 | 10篇 |
能源动力 | 7篇 |
轻工业 | 7篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
无线电 | 8篇 |
一般工业技术 | 80篇 |
冶金工业 | 2篇 |
原子能技术 | 3篇 |
自动化技术 | 38篇 |
出版年
2023年 | 2篇 |
2022年 | 8篇 |
2021年 | 8篇 |
2020年 | 5篇 |
2019年 | 5篇 |
2018年 | 11篇 |
2017年 | 2篇 |
2016年 | 4篇 |
2015年 | 7篇 |
2014年 | 7篇 |
2013年 | 19篇 |
2012年 | 13篇 |
2011年 | 16篇 |
2010年 | 12篇 |
2009年 | 22篇 |
2008年 | 10篇 |
2007年 | 8篇 |
2006年 | 10篇 |
2005年 | 7篇 |
2004年 | 10篇 |
2003年 | 11篇 |
2002年 | 7篇 |
2001年 | 9篇 |
2000年 | 12篇 |
1999年 | 5篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 7篇 |
1995年 | 6篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1977年 | 3篇 |
排序方式: 共有268条查询结果,搜索用时 15 毫秒
1.
Aleksandar Miletić Peter Panjan Miha Čekada Lazar Kovačević Pal Terek Janez Kovač Goran Dražič Branko Škorić 《Ceramics International》2021,47(2):2022-2033
With the goal to produce a hard and tough coating intended for tribological applications, CrAlN/TiSiN nanolayer coating was prepared by alternative deposition of CrAlN and TiSiN layers. In the first part of the article, a detailed study of phase composition, microstructure, and layer structure of CrAlN/TiSiN coating is presented. In the second part, its mechanical properties, fracture and tribological behavior are compared to the nanocomposite TiSiN coating. An industrial magnetron sputtering unit was used for coating deposition. X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy were used for compositional and microstructural analysis. Mechanical properties and fracture behavior were studied by instrumented indentation and focused ion beam techniques. Tribological properties were evaluated by ball-on-disk test in a linear reciprocal mode. A complex layer structure was found in the nanolayer coating. The TiSiN layers were epitaxially stabilized inside the coating which led to formation of dislocations at interfaces, to introduction of disturbances in the coating growth, and as a result, to development of fine-grained columnar microstructure. Indentation load required for the onset of fracture was twice lower for the nanolayer CrAlN/TiSiN, compared to the nanocomposite TiSiN coating. This agrees very well with their mechanical properties, with H3/E2 being twice higher for the TiSiN coating. However, the nanolayer coating experienced less severe damage, which had a strong impact on tribological behavior. A magnitude of order lower wear rate and four times lower steady state friction coefficient were found for the nanolayer coating. 相似文献
2.
Monitoring of nitrate (NO3-) and nitrite (NO2-) content in agricultural products in Slovenia has been carried out since 1996. The results of monitoring over the period 1996-2002 are presented. During this time 924 samples of 14 different agricultural products (potato, lettuce, apples, carrot, silage maize, cabbage, grapes, peaches, string beans, cereals, pears, cucumbers, strawberries and tomato) were analysed. The samples were taken at the time of maturity directly from growing sites and they were analysed using segmented flow analysis. The average nitrate contents were the highest in lettuce (1074 mg kg-1), cabbage (881 mg kg-1), string beans (298 mg kg-1) and carrot (264 mg kg-1), and they were moderately high in potato (158 mg kg-1), silage maize (122 mg kg-1), strawberries (94 mg kg-1), cucumbers (93 mg kg-1) and cereals (49 mg kg-1). Low nitrate contents (below 6 mg kg-1) were found in fruit (grapes, peaches, apples and pears) and tomato. With the exception of cereals (8.9 mg kg-1), apples (1.5 mg kg-1), potato (1.2 mg kg-1) and pears (1.0 mg kg-1) the content of nitrites did not exceed 0.5 mg kg-1. It may be concluded that the results of the monitoring were in most cases similar to the results of investigations obtained in other countries. 相似文献
3.
4.
The microstructure and properties of NdFeB sintered permanent magnets were analysed by different methods. Samples analysed were sintered and thermally treated. The hard magnetic Nd2Fe14B phase and amorphous neodymium-rich phase were observed by TEM. The neodymium-rich phase contained iron and boron, in elemental and in B2O3 form, which is known as a glass former. At the sintering temperature, Nd2Fe14B and the neodymium-rich phase are supersaturated with iron, which should be dissolved at the annealing temperature to react with neodymium and boron and form additional Nd2Fe14B phase. Iron precipitates of size up to 2 nm were detected in the Nd2Fe14B phase. These superparamagnetic precipitates of -Fe could affect the hard magnetic properties of NdFeB magnets. 相似文献
5.
6.
Hana Marko Janez Marina Santo Silvo Sre
o Marija 《Sensors and actuators. B, Chemical》2008,133(2):699-704
In this paper we present a novel approach to preparing large-displacement 65Pb(Mg1/3Nb2/3)O3–35PbTiO3/Pt (65/35 PMN–PT/Pt) bimorph actuators. These “substrate-free”, bending-type actuators were prepared by screen-printing the 65/35 PMN–PT and Pt thick-film pastes as the electrodes on alumina substrates. After this screen printing and the subsequent firing the 65/35 PMN–PT/Pt composites were peeled off from the substrates. Displacements of nearly 100 μm at 18 V were achieved for actuators with dimensions of 1.8 cm × 2.5 mm × 50 μm for the 65/35 PMN–PT layer. The normalized displacement (the displacement per unit length) was 40 μm/cm at 18 V. The experimental results together with a computation procedure were used to obtain the material parameters for a finite-element analysis of the 65/35 PMN–PT/Pt bimorph actuators. 相似文献
7.
8.
9.
10.
Abstract There has been a great deal of research on characterising bulk solids. However, some of the characteristics, particularly the time‐dependent and random changes of properties, still remain insufficiently understood. The focus of this article is to study the influence of particle size, size distribution, moisture content, and particle shape on the unconfined yield strength of bulk solids. We present some interesting results about the influence of the particle size distribution on the unconfined yield strength of a bulk solid and a new method for determining the influence of particle shape on the unconfined yield strength of a bulk solid, which was made possible by the design and use of a novel attritor. 相似文献