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991.
二甲苯不饱和聚酯树脂在30%硝酸中的腐蚀行为 总被引:1,自引:0,他引:1
通过失重及表面腐蚀层厚度的测定以及红外吸收光谱(FT-IR)、扫描电镜(SEM)等分析手段研究了二甲苯不饱和聚酯树脂(SUPR)在30%硝酸溶液中的腐蚀行为,提出了材料耐该介质腐蚀的机理。结果表明,失重和表面腐蚀层厚度经一定时间浸泡后趋于稳定,不同温度下达到的稳定失重和腐蚀层厚度值不同。腐蚀机理为:浸泡过程中试样表面发生了物理吸附及化学反应,形成了一层淡黄色的特,其厚度与温度有关。该层物质阻止了硝 相似文献
992.
Naphthenic acid corrosion (NAC) and erosion-corrosion (NAEC) behavior of Mo-bearing (0-7.0 wt.%) stainless steels have been investigated in laboratory to evaluate the essential role of Mo on their NAC and NAEC resistance. The NAC and NAEC resistance of a high-velocity-oxygen-fuel (HVOF) thermal sprayed Mo-bearing stainless-steel coating was also investigated in both laboratory and an oil refinery. It was found that increasing the Mo content remarkably enhanced the NAC and NAEC resistance of stainless steels. The Mo-rich areas or phases in the steels played an importance role in resisting the NAEC. The HVOF coating showed excellent NAC and NAEC resistance in laboratory tests. The 700-day field test in an oil refinery revealed that the coating can effectively prevent the carbon-steel substrate from erosion-corrosion during long-term exposure in oil-refining environment. The corresponding NAC and NAEC mechanisms of the stainless steels and the beneficial role of Mo were discussed by taking account of inherent susceptibility of metal elements to corrosion, possible effects of Mo on surface films, and Mo-induced change in microstructure and microhardness. 相似文献
993.
ZHAO Xuehui ) HUANG Kelong) JIAO Feipeng) LI Zhiaojian) and PENG Xiahui) ) College of Chemistry Chemical Engineering Central South University Changsha China ) Chemistry Department Hunan Technology BOE Science University Zhuzhou China 《稀有金属(英文版)》2006,(2)
1. Introduction Rare earth elements have an important function inlife process. The fluorescence enhancement of lan-thanides in aqueous solutions has therefore becomean area of active study in trace-level estimation oflanthanides using spectrofluorimetry [1]. Its possiblemechanism and application as fluorescence probesin biological systems have also attracted attention inrecent years [2]. Generally, fluorescence enhance-ment can be achieved through ligand sensitization.Various ligands have bee… 相似文献
994.
995.
1 INTRODUCTIONThereservesofniobium containingmineralsinChinatakethesecondplaceintheworld ,anddis tributemainlyinBaiyuneboofInnerMongolia ,TaimeiofGuangdongProvinceandYichunofJiangxiProvince ,etc .Niobium containingmineralsweredis coveredover 130kinds ,butonlyafewofthemhadindustrialvalue .Fersmiteisoneoftheseveralvaluedindustrialniobium containingminerals[1,2 ] .Theprocessingofniobium containingmineralsistoodifficultduetotheirfinesizeandnumerousspeciesandcomplexcomposing .Inmiddleperi… 相似文献
996.
不锈钢,铜和铝合金酸性土壤腐蚀行为研究 总被引:4,自引:2,他引:4
研究了1Cr13,1Cr18Ni9Ti,H62黄铜和Ly11铝合金在酸性土壤中的腐蚀行为,结果表明,Ly11铝合金的腐蚀率比不锈钢的腐蚀率约大50倍,发现Ly11铝合金在不同种的酸性土壤中的腐蚀率与其腐蚀产物的相结构有一定的对应关系 相似文献
997.
溶剂萃取法从废电子元件中回收钯 总被引:4,自引:3,他引:4
用溶剂萃取法从硝酸浸取液中提取Pd~(2+)与Cu~(2+),Ni~(2+).N_(235)作Pd~(2+)的萃取剂,煤油作稀释剂,癸醇作调相剂,最佳工艺条件是萃取剂组成,25%N_(235)—10%癸醇—65%煤油;硝酸浓度,0.5~3mol/L;温度,室温;1.5mol/L HNO_2作负载有机相杂质离子Ni~(2+),Cu~(2+)的洗涤剂,其一次洗涤率近100%;6%硫脲,或5%氨水作负载有机相中Pd~(2+)的反萃剂,其一次反萃率分别为98.6%,68.5%. 相似文献
998.
The fluorescence of terbium (Ⅲ) was enhanced by about three orders of magnitude in the presence of trimellitic acid (benzene-l, 2, 4-tricarboxylic acid (TLA)) in aqueous solution at pH 6. The fluorescence intensity could be greatly increased when the system of Tb3+-TLA was treated with La3+ (or Gd3+) and TritonX- 100. The addition of La3+ (or Gd3+) enhances the fluorescence of the system by about two orders of magnitude due to cofluorescence, and the TritonX-100 micellar medium plays an important role for stabilization of the system. Both the intermolecular energy transfer mode and intramolecular energy transfer mode are responsible for the mechanism of fluorescence enhancement. In the optimum conditions, the fluorescence intensity is a linear function of Tb3+ concentration in the range of 7.8 × 10-9-3.6 × 10-6 mol/L for the system Tb3+-La3+-TLA and 1.0 × 10-8-4.7 × 10-6 mol/L for the system Tb3+-Gd3+-TLA, and the limits of detection are 4.6 ×10-10 mol/L and 6.0 × 10-10 mol/L, respectively. 相似文献
999.
1000.
ZHANG Xiuying LOU Xiangdong YIN Guoyin and ZHANG Youjua
) College of Chemistry Environmental Science Key Laboratory of Environmental Science Engineering Education Commission of Henan Henan Normal University Xinxiang China
) Anyang teachers college Anyang China 《稀有金属(英文版)》2004,(1)
The extraction behavior and mechanism of gallium(Ⅲ) and thallium(Ⅰ) or indium(Ⅲ) and thallium(Ⅰ) with Sec-octylphenoxy acetic acid (CA-12) from hydrochloric acid solution in sulphonating kerosene were studied. Optimum extraction conditions were evaluated from critical study of various experimental parameters and the probable composition of the extracted species is ascertained from lg D-lg C plots. The effects of different ions on the determination of these ions were examined. 相似文献