全文获取类型
收费全文 | 7885篇 |
免费 | 710篇 |
国内免费 | 768篇 |
专业分类
电工技术 | 176篇 |
综合类 | 356篇 |
化学工业 | 597篇 |
金属工艺 | 3438篇 |
机械仪表 | 602篇 |
建筑科学 | 210篇 |
矿业工程 | 79篇 |
能源动力 | 183篇 |
轻工业 | 167篇 |
水利工程 | 8篇 |
石油天然气 | 358篇 |
武器工业 | 59篇 |
无线电 | 104篇 |
一般工业技术 | 1299篇 |
冶金工业 | 1514篇 |
原子能技术 | 201篇 |
自动化技术 | 12篇 |
出版年
2024年 | 22篇 |
2023年 | 135篇 |
2022年 | 255篇 |
2021年 | 294篇 |
2020年 | 284篇 |
2019年 | 246篇 |
2018年 | 197篇 |
2017年 | 318篇 |
2016年 | 322篇 |
2015年 | 374篇 |
2014年 | 451篇 |
2013年 | 613篇 |
2012年 | 585篇 |
2011年 | 641篇 |
2010年 | 447篇 |
2009年 | 499篇 |
2008年 | 370篇 |
2007年 | 468篇 |
2006年 | 429篇 |
2005年 | 398篇 |
2004年 | 371篇 |
2003年 | 269篇 |
2002年 | 222篇 |
2001年 | 178篇 |
2000年 | 176篇 |
1999年 | 138篇 |
1998年 | 106篇 |
1997年 | 101篇 |
1996年 | 103篇 |
1995年 | 69篇 |
1994年 | 65篇 |
1993年 | 51篇 |
1992年 | 39篇 |
1991年 | 23篇 |
1990年 | 23篇 |
1989年 | 30篇 |
1988年 | 8篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 7篇 |
1984年 | 7篇 |
1983年 | 5篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1980年 | 2篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1959年 | 3篇 |
排序方式: 共有9363条查询结果,搜索用时 15 毫秒
1.
Nicolas Larché Benoit Emo Audrey Allion Elisabeth Johansson Dominique Thierry 《工业材料与腐蚀》2021,72(8):1338-1349
With lower alloying cost and higher mechanical properties, lean duplex stainless steels can be an alternative to the more commonly used austenitic stainless steels. However, these alloys are still not the preferred choice, probably due to a lack of field experience. A study was thus initiated in view of defining the limits of use of selected (lean) duplexes for urban wastewater treatment units. The present paper shows the localized corrosion performance of selected lean duplexes in chloride contaminated solutions. The results are compared with austenitic S30403 and S31603 and with the more standard duplexes S82441 and S32205. The effect of welding was also investigated. Exposures in field municipal wastewater plants were conducted for 1 year in low and high chloride content units. The results show that lean duplexes S32101 and S32202 can be used as alternatives to S30403 and S31603 in low chloride electrolytes. At 500 ppm of chloride content, duplex stainless steel S32304 showed better corrosion resistance than S30403 and S31603. For higher chloride contents (1000 ppm and above) the standard duplexes S82441 and S32205 shall be preferred. 相似文献
2.
3.
Muntasir Hashim Farnoosh Farhad David Smyth‐Boyle Robert Akid Xiang Zhang Philip J. Withers 《工业材料与腐蚀》2019,70(11):2009-2019
The environmental performance of 316L grade stainless steel, in the form of tensile specimens containing a single corrosion pit with various aspect ratios, under cyclic loading in aerated chloride solutions is investigated in this study. Results from environmental tests were compared and contrasted with those obtained using finite element analysis (FEA). Fractography of the failed specimens obtained from experiments revealed that fatigue crack initiation took place at the base of the shallow pit. The crack initiation shifted towards the shoulder and the mouth of the pit for pits of increasing depth. This process is well predicted by FEA, as the strain contour maps show that strain is the highest around the centric strip of the pit. However, for shallow pits, local strain is uniformly distributed around that strip but begins to concentrate more towards the shoulder and the mouth region for increasingly deep pits. 相似文献
4.
5.
6.
Electrochemical impedance spectroscopy (EIS), anodic polarization and scanning electron microscopy techniques were used to investigate the damage mechanism in the transpassive potential region of AISI ... 相似文献
7.
8.
Jialong Tian M. Babar Shahzad Wei Wang Lichang Yin Zhouhua Jiang Ke Yang 《材料科学技术学报》2018,34(9):1671-1675
The effect of Co addition on the formation of Ni-Ti clusters in maraging stainless steel was studied by three dimensional atom probe (3DAP) and first-principles calculation. The cluster analysis based on the maximum separation approach showed an increase in size but a decrease in density of Ni-Ti clusters with increasing the Co content. The first-principles calculation indicated weaker Co-Ni (Co-Ti) interactions than Co-Ti (Fe-Ti) interactions, which should be the essential reason for the change of distribution characteristics of Ni-Ti clusters in bcc Fe caused by Co addition. 相似文献
9.
摘 要:主要介绍Sasol Agri公司硫酸四系统的技术改造,分两步进行,第一步更换转化器、热换热器及主省煤器,生产能力由1600t/d提高到1750 t/d,且鼓风机出口压力很低。第二步更换干燥塔、二吸塔及冷换热器,连续生产能力在1950 t/d以上。使用不锈钢材质及克瓦纳·凯密迪公司专有的换热器,使装置的改造相当成功,维护及操作费用较低,并具有较大的灵活性和可操作性。 相似文献
10.