全文获取类型
收费全文 | 916篇 |
免费 | 77篇 |
国内免费 | 196篇 |
专业分类
电工技术 | 8篇 |
综合类 | 51篇 |
化学工业 | 82篇 |
金属工艺 | 643篇 |
机械仪表 | 54篇 |
建筑科学 | 18篇 |
矿业工程 | 7篇 |
能源动力 | 10篇 |
轻工业 | 13篇 |
水利工程 | 3篇 |
石油天然气 | 59篇 |
武器工业 | 3篇 |
无线电 | 5篇 |
一般工业技术 | 136篇 |
冶金工业 | 87篇 |
原子能技术 | 8篇 |
自动化技术 | 2篇 |
出版年
2024年 | 4篇 |
2023年 | 8篇 |
2022年 | 37篇 |
2021年 | 38篇 |
2020年 | 35篇 |
2019年 | 37篇 |
2018年 | 31篇 |
2017年 | 66篇 |
2016年 | 64篇 |
2015年 | 44篇 |
2014年 | 42篇 |
2013年 | 63篇 |
2012年 | 76篇 |
2011年 | 77篇 |
2010年 | 51篇 |
2009年 | 69篇 |
2008年 | 31篇 |
2007年 | 40篇 |
2006年 | 41篇 |
2005年 | 42篇 |
2004年 | 41篇 |
2003年 | 45篇 |
2002年 | 31篇 |
2001年 | 38篇 |
2000年 | 27篇 |
1999年 | 29篇 |
1998年 | 12篇 |
1997年 | 12篇 |
1996年 | 16篇 |
1995年 | 5篇 |
1994年 | 7篇 |
1993年 | 7篇 |
1992年 | 12篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有1189条查询结果,搜索用时 15 毫秒
11.
离子注入对铁及其低合金、铝及其合金耐腐蚀性能的影响 总被引:1,自引:0,他引:1
离子注入对金属腐蚀行为的研究已达30年.研究结果表明离子注入对改变金属表面成分和表面性能是极为有效的技术.本文概述了离子注入对铁及其低合金、铝及其合金的腐蚀电化学行为的影响.涉及的注入离子达十余种。 相似文献
12.
From the corrosion fatigue test under intermit-tent wetting condition for offshore structural steelof A537 cl.l and data analysis,some results associ-ated with the role of pits in fatigue process havebeen discussed. 相似文献
13.
The resistance to pitting corrosion of austenitic stainless steel Cr18Mn12N has been studied in model solutions of sulphuric
acid (0.5 m) containing chloride ions (0.5 m). The cyclic potentiodynamic method has been employed to investigate the effects of chloride ions and agitation rate on the
pitting and repassivation potentials. Electron and optical microscopy, electron diffraction spectroscopy and atomic absorption
spectrometry have been used to detect the surface sites for pit formation and the growth of pit nuclei. The results obtained
with chromium–manganese–nitrogen steel have been compared with those of austenitic Cr18Ni9 stainless steel. A similarity in
pit initiation is established, while steel composition exhibits no significant effect. Cr18Mn12N steel is less prone to repassivation
as compared with Cr18Ni9 steel. 相似文献
14.
Failure analysis and a study of the wear mechanism were performed on a heavily loaded carburized gear with some unusual features. The analysis showed that the different failure forms on the tooth surface of the gear were dependent on the sub-surface shearing stress, the lubrication conditions and the surface roughness. Delaminations formed on the addendum surface were the main reason for the gear failure. A suggestion for improvement has been tried, and a desirable result has been obtained. 相似文献
15.
The generation of surface roughness during slurry erosion-corrosion and its effect on the pitting potential 总被引:1,自引:0,他引:1
Results of experiments performed to isolate the effect of surface roughness generated during slurry erosion-corrosion of 304L stainless steel are presented. Surfaces prepared by grinding to different finishes show that increasing the roughness lowers the pitting potential in chloride solution. Subsequent erosion by an aqueous sand slurry then alters this pitting potential (Ep), as measured in the solution phase alone, in a manner dependent on the initial surface roughness. Surfaces which were initially rougher show a pronounced rise in p after erosion, while those with an initially smoother finish show a fall in Ep after erosion. Measurement of Ep during erosion-corrosion does not fit either process, with values of Ep lower than those predicted from the surface roughness alone. 相似文献
16.
17.
Corrosion-Electrochemical behavior of a commercial API5CT grade L80 type 13Cr tubing enriched with microalloying elements
is studied in 6, 7.5, 9, 12 and 15% HCl solutions by electrochemical methods. The objective is to contribute to the comprehension
of corrosion phenomena caused by HCl of similar concentrations, generally used in acidizing job. The corrosion morphology
is examined by scanning electron microscopy (SEM) coupled with EDAX. The soluble corrosion products are analyzed by atomic
absorption spectroscopy and colorimetric methods. General, as well as localized, corrosion is present. The severest general
corrosion with a maximum rate of 26 mm/year is obtained at 15% HCl. The localized corrosion which morphologically differs
as function of HCl concentrations is revealed by SEM investigation. In all the above HCl solutions, the commercial 13% Cr
martensitic stainless steel tubing shows no passive state. Above 6% HCl, the microalloying elements promote forming a discontinuous
film of the corrosion products. The corrosion rate slightly decreases in 15% HCl compared to the published data on a conventional
13% Cr martensitic stainless steel tubing. This is due to both the chemical composition (silicon, manganese and vanadium)
and microstructural properties. Copper seems to additionally accelerate the corrosion of the alloy.
Published in Russian in Zashchita Metallov, 2007, Vol. 43, No. 4, pp. 372–380.
The article was translated by the authors in English. 相似文献
18.
19.
Corrosion in wet lime/limestone systems used for flue gas desulfurization in thermal power plants is of great concern. The
frequent variations in acidity and in chloride and fluoride ion concentrations experienced by such systems pose a serious
threat to the materials of construction. Currently used materials mostly type 316L stainless steel often fail to meet their
life expectancy. The present study evaluates the performance of advanced Ni- Cr- Mo alloys 59 and C- 276 in a simulated sulfur
dioxide scrubber environment. Accelerated tests showed that high Ni- Cr- Mo alloys have little tendency to leach metal ions
such as chromium, nickel, and molybdenum at different impressed potentials. Scanning electron microscopy was used to examine
the morphology of pitting attack. 相似文献
20.
工业纯Al的缝隙腐蚀再钝化电位 总被引:1,自引:0,他引:1
工业纯Al的缝隙腐蚀再钝化电位ER是缝隙结构的特征值,与缝隙腐蚀下限电位VCREV一致,比孔蚀电位负约100mV,说明缝隙腐蚀更易发生. 相似文献