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991.
Summary Cobalt(II) can be determined in 0.1 mol/l Na3citrate + 0.1 mol/l NH4Cl + 0.08% dimethylglyoxime as supporting electrolyte in the presence of a 50 000-fold excess of zinc by differential pulse polarography. The limit of determination is 4.2×10–5 mol/l Co (2.5 mg/l). Linear calibration curves are obtained within the range of 1×10–7 to 5×10–6 mol/l cobalt without zinc and in the presence of 5×10–3 mol/l Zn. The analytical method developed is suitable for the determination of cobalt in zinc plant solutions.
Cobaltbestimmung in Gegenwart hoher Zinkkonzentrationen mit Hilfe der Differential-Puls-Polarographie相似文献
992.
Travasso RD Buxton GA Kuksenok O Good K Balazs AC 《The Journal of chemical physics》2005,122(19):194906
Through a combination of simulation techniques, we determine both the structural evolution and mechanical properties of blends formed from immiscible ternary mixtures. In this approach, we first use the lattice Boltzmann method to simulate the phase separation dynamics of A/B/C fluid mixtures for varying compositions within the spinodal region. We also investigate the effect of an imposed shear on the phase ordering of the mixture. We assume that the fluid is quenched sufficiently rapidly that the phase-separated structure is preserved in the resultant solid. Then, the output from our morphological studies serves as the input to the lattice spring model, which is used to simulate the elastic response of solids to an applied deformation. These simulations reveal how the local stress and strain fields and the global Young's modulus depend on the composition of the blend and the stiffness of the components. By comparing the results for the sheared and unsheared cases, we can isolate optimal processing conditions for enhancing the mechanical performance of the blends. Overall, the findings provide fundamental insight into the relationship between structure, processing, and properties for heterogeneous materials and can yield guidelines for formulating blends with the desired macroscopic mechanical behavior. 相似文献
993.
Rare-earth oxide nanopolyhedra, nanoplates, and nanodisks 总被引:2,自引:0,他引:2
994.
995.
996.
In this work, new glass compositions in the TeO2-GeO2-Nb2O5-K2O system have been prepared and studied. The germanotellurite glasses were prepared by melt-quenching and their density, refractive index and characteristic temperatures have been determined. The structure of these glasses has been studied by infrared and Raman spectroscopies.The progressive replacement of TeO2 by GeO2 led to an increase of the glass transition and crystallisation temperatures of the glasses and a simultaneous decrease of their density and refractive index. Typical density and refractive index values of these glasses ranged from 4.98 to 3.85 g cm− 3 and 2.08 to 1.79, respectively, with increasing GeO2 content. The infrared spectra are dominated by a band ~ 640 cm− 1 in the tellurite glass and ~ 800 cm− 1 in the germanate glass. The Raman spectra of the germanotellurite glasses present an intense boson peak between ~ 34 and 47 cm− 1, together with high frequency peaks at ~ 670 cm− 1 and ~ 470 cm− 1 for high tellurite and high germanate glass compositions, respectively. The vibrational spectra of these germanotellurite glasses indicate that the glass network consists basically of TeO4 and [TeO3]/[TeO3 + 1] units, mixed with GeO4 and NbO6 polyhedra. 相似文献
997.
998.
利用等离子体增强化学气相沉积法制备Si-rich SiNx/N-rich SiNy多层膜,分别使用热退火和激光辐照技术对多层膜进行退火,以构筑三维限制、尺寸可控、有序的硅纳米晶.实验结果表明,经退火后,纳米硅晶粒在Si-rich SiNx子层内形成,其尺寸可由Si-rich SiNx子层厚度调控.实验还发现,激光辐照技术相比于热退火能更有效地改善多层膜的微结构,提高多层膜的晶化率,以激光技术诱导晶化的Si-rich SiNx/N-rich SiNy多层膜作为有源层构建电致发光器件,在室温下观察到了增强的电致可见发光,并且发光效率较退火前提高了40%以上.
关键词:
氮化硅
多层膜
限制结晶
纳米晶硅 相似文献
999.
1000.
我们利用单杂质Anderson模型及运动方程等理论,通过求解格林函数的方法研究了通过T型量子点结构(耦合于铁磁电极和介观环量子点结构)的自旋极化输运过程.研究结果表明,与量子点相耦合的铁磁电极中的极化强度是控制量子点电子输运的重要参数,由此可以达到自旋阀效应.另外我们还发现与量子点相耦合的介观环中的磁通会影响电子自旋向上和自旋向下近藤共振峰的分裂程度,但若加入适当的外磁场,那么这样的分裂将被抵消。 相似文献