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61.
Density functional theory (DFT) slab calculations, mainly using the generalised gradient approximation, have been used to investigate the minimum energy structures of molecular SO2 and SO3 on Cu(1 1 1) and Ni(1 1 1) surfaces. On Ni(1 1 1) the optimal local adsorption structures are in close agreement with experimental results for both molecular species obtained using the X-ray standing wavefield technique, although for adsorbed SO2 the energetic difference between two alternative lateral positions of the lying-down molecule on the surface is marginally significant. On Cu(1 1 1) the results for adsorbed SO2, in particular, were sensitive to the DFT functional used in the calculations, but in all cases failed to reproduce the experimentally-established preference for adsorption with the molecular plane perpendicular to the surface. This result is discussed in the context of previously published DFT results for these species adsorbed on Cu(1 0 0). The optimal geometry found for SO3 on Cu(1 1 1) is similar to that on Ni(1 1 1), providing agreement with experiment regarding the molecular orientation but not the adsorption site. 相似文献
62.
火焰原子吸收光谱法测定中药防风中铜、锰、锌和铁的不确定度评定 总被引:1,自引:0,他引:1
采用HNO3和HClO4消解防风样品,利用火焰原子吸收光谱法测定其中铜、锰、锌和铁含量.对测量过程中不确定度的产生原因进行了分析,并对防风中4种元素含量测定结果的不确定度进行了评定. 相似文献
63.
142名健康成人血清铜的含量测定 总被引:3,自引:0,他引:3
本文用原子吸收法对吉林市142名健康成人血清铜的含量进行了测定。结果表明,男性血清铜值稍代于女性,但经统计学处理无显著性差异(P>0.05)。提出其正常值范围。 相似文献
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66.
通过测定Nd∶YAG脉冲激光烧蚀金属Cu诱导产生光谱线及其强度随时间与空间的分布,结果表明等离子体辐射光谱线由原子光谱线、离子光谱线及连续辐射背景光组成,Cu原子光谱线的数目不仅比离子光谱线多,而且辐射强度比离子光谱线的大,以连续辐射背景光的辐射强度为最弱;原子光谱线的发光范围最大,持续时间最长;离子光谱线发光范围中等,持续时间中长;连续辐射背景光的发光范围最小,持续时间最短.讨论了激光诱导发光的机理,认为等离子体羽中连续辐射背景光主要来自近靶处高能电子的韧致辐射和电子与离子的复合激发,原子和离子光谱线主要由等离子体中高能电子的碰撞传能激发所引起,并用之较好地解释了所观察的实验现象. 相似文献
67.
The behavior of copper precipitation in cast multicrystalline silicon (mc-Si) annealed at different temperatures under air cooling (30 K/s) or slow cooling (0.3 K/s) was investigated by scanning infrared microscopy (SIRM). Comparing to Czochralski-grown silicon (Cz-Si), copper precipitated more easily in mc-Si, and the lowest temperature of copper precipitation in mc-Si was about 700 °C, lower than that in Cz-Si. It was also observed that copper preferably precipitated on grain boundaries so that near the grain boundaries the denuded zone formed. The results indicate that the defects including dislocations, grain boundaries and microdefects, as the heteronucleation sites, enhanced copper precipitation. Moreover, cooling rates had a great influence on the copper precipitation, especially at lower annealing temperatures. Generally air cooling led to the formation of high density of copper-precipitate colonies. 相似文献
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Shiheng Yin Dongxiao WuJi Yang Shumei LeiTongchun Kuang Bin Zhu 《Applied Surface Science》2011,257(20):8481-8485
Biomimic superhydrophobic surfaces with contact angle greater than 150° and low sliding angle on copper substrate were fabricated by means of a facile solution immersion and surface self-assembly method. The scanning electron microscopy showed a nanoneedle structure copper surface with sporadic flower-like aggregates after treatment with sodium hydroxide and potassium persulfate solution. X-ray photoelectron spectroscopy and X-ray diffraction results confirmed that the formed nanoneedles were crystallized Cu(OH)2. And the hydrophilic Cu(OH)2 surface can be further modified into superhydrophobic through surface self-assembly with dodecanoic acid. 相似文献
70.
B. Macalik L. Krajczyk J. Okal T. Morawska-Kowal K. D. Nierzewski M. Suszyńska 《辐射效应与固体损伤》2013,168(6-12):887-893
The ion-exchange process was used to introduce copper ions into soda lime silicate glasses (SLS), the composition of which corresponds to the miscibility gape in the Na 2 O-SiO 2 system. The samples have been immersed either in a molten Cu 2 Cl 2 or CuCl 2 at various temperatures from the range 720-940 v K for different time. The observed green colour of glass is related with the 790-nm absorption band related to the cupric ions. The annealing either in air or in the hydrogen atmosphere was used for the reduction of copper. The effectiveness of these procedures was analysed on a basis of the penetration profiles monitored by roentgenographic methods (diffraction and EDAX). Transmission electron microscopy (TEM) observations of the replicated surface and common optical absorption measurements have been used to study the morphology of the dopant ions. 相似文献