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141.
介绍了电泳技术制备YBCO高温超导厚膜的实验方法和YBCO高温超导厚膜的电学性质测量 ,讨论了在学生小型科研实验或设计实验中开展此实验的学时安排、注意事项和实验内容的扩展 . 相似文献
142.
143.
低能离子对酪氨酸溶液损伤作用的光谱研究初报 总被引:4,自引:3,他引:4
利用气体我放电产生低能离子,其在放电间隙的电场加速下撞击水溶液样品。了低能离子作用后酪氨酸溶液的紫外及红外吸收光谱的变化。结果表明,气体放电产生的离子对Tyr造成了多种损伤。不仅使化学键断裂,分子解体,而且外来的活性离子会与溶液中的元素形成新的化学基团,妆在受损伤分子碎片上组成新的损伤物质,充分体现了低能离子与物质相互作用的“离子沉积”效应。 相似文献
144.
采用双槽电化学腐蚀法以电阻率为10-15 Ω·cm的p型<100>晶向的单晶硅片制备了孔径约为1.5 μm, 孔深约为15-20 μm的p型多孔硅, 并以此多孔硅作为基底采用无电沉积法通过调控沉积时间在其表面沉积了不同厚度的银纳米颗粒薄膜. 采用扫描电子显微镜和X 射线衍射仪表征了银纳米颗粒/多孔硅复合材料的形貌和微观结构, 结果表明银纳米颗粒较均匀的分布于多孔硅的表面上且沉积时间对产物的形貌有重要影响. 采用静态配气法在室温下研究了银纳米颗粒/多孔硅复合材料对NH3的气敏性能. 气敏测试结果表明沉积时间对产物的气敏性能影响较大. 当沉积时间较短时, 适量银纳米颗粒掺杂的多孔硅复合材料由于其较高的比表面积以及特殊的形貌和结构, 对NH3气体表现出较高的灵敏度、优良的响应/恢复性能. 室温下, 其对50 ppm 的NH3气体的气敏灵敏度可以达到5.8左右. 相似文献
145.
离子束辅助淀积低温微光学元件红外宽带增透膜 总被引:1,自引:0,他引:1
简要叙述了锗基片微光学元件红外宽带减反膜的设计与制作。着重介绍了离子束辅助淀积制备该膜系的过程,给出了用该方法制作8~12μm波段的减反膜的测试曲线,它具有峰值透过率高,在设计波长范围内的平均透过率大于97%以上,膜层附着好,可以切割和擦洗,可以在室温和100K低温下反复循环使用。 相似文献
146.
The adsorption and decomposition of monoethylgermane (GeH3Et) on the Si(100)-(2×1) surface was investigated with the intent of elucidating the surface processes leading to the deposition of germanium. The low-temperature adsorption of the molecule was explored, as well as its thermal decomposition. H2 and C2H4 are observed as the desorption products in temperature-programmed desorption experiments. The ethylene is produced by a hydride elimination reaction within the adsorbed ethyl groups. The amount of Ge which can be deposited in a reaction cycle is correlated with the number of sites occupied by the ethyl groups upon the dissociation of GeH3Et. 相似文献
147.
Hydrogen generation from formic acid (FA) has received significant attention.The challenge is to obtain a highly active catalyst under mild conditions for practical applications.Here atomic layer deposition (ALD) of FeOx was performed to deposit an ultrathin oxide coating layer to a Pd/C catalyst,therein the FeOx coverage was precisely controlled by ALD cycles.Transmission electron microscopy and powder X-ray diffraction measurements suggest that the FeOx coating layer improved the thermal stability of Pd nanoparticles (NPs).X-ray photoelectron spectroscopy measurement showed that deposition of FeOx on the Pd NPs caused a positive shift of Pd3d binding energy.In the FA dehydrogenation reaction,the ultrathin FeOx layer on the Pd/C could considerably improve the catalytic activity,and Pd/C coated with 8 cycles of FeOx showed an optimized activity with turnover frequency being about 2 times higher than the uncoated one.The improved activities were in a volcanoshape as a function of the number of FeOx ALD cycles,indicating the coverage of FeOx is critical for the optimized activity.In summary,simultaneous improvements of activity and thermal stability of Pd/C catalyst by ultra-thin FeOx overlayer suggest to be an effective way to design active catalysts for the FA dehydrogenation reaction. 相似文献
148.
S. Abboudy A. Al-Hajri A. A. Al-Shahrani M. S. Al-Assiri L. Abulnasr A. Sweyllam A. W. Brinkman 《Il Nuovo Cimento D》1998,20(12):1881-1890
Summary A series of zinc stannate (Zn2 SnO4) thin films were prepared at four different substrate temperatures; namely, room-temperature (25°C), 50°C, 100°C and 200°C.
Direct-current resistivity measurements were performed on these samples in the temperature range from room temperature (∼290
K) up to about 500 K. A phase transition (of positive temperature coefficient (PTC) of resistance) was observed in the thin
film grown at room temperature at about 385 K. Other investigated samples showed a semiconducting behaviour of three distinct
conduction mechanisms extending from intrinsic to thermal freeze-out conduction. The width of the band gapE
g
was found to depend on the substrate temperature and was discussed in terms of a formation of a band tailing. Thermal freeze-out
was dominant at the lower temperature region.
On leave from Department of Physics, Faculty of Science, Alexandria University, Alexandria, Egypt. 相似文献
149.
I. A. Viktorov V. F. Gremenok I. V. Bodnar A. E. Hill R. D. Pilkington M. V. Yakushev R. D. Tomlinson 《Journal of Applied Spectroscopy》1999,66(4):659-663
We investigated the photoacoustic spectra of polycrystalline thin CuInSe2 films obtained by the method of pulsed laser evaporation onto glass substrates at 100–450°C. The spectra were taken near
the fundamental optical absorption edge using a high-resolution spectrometer and microphone-type sensor. We show the relation
between the photoacoustic spectrum and the structural properties of films. The interference effect observed is discussed.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 4, pp. 583–586, July–August, 1999. 相似文献
150.