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排序方式: 共有143条查询结果,搜索用时 15 毫秒
1.
ANALYSIS OF THE X-RAY PHOTOELECTRON SPECTRA OF a-SiOCF FILMS PREPARED BY PLASMA-ENHANCED CHEMICAL VAPOUR DEPOSITION 下载免费PDF全文
The preparation of a-SiOCF films from Si(OC2H5)4, C4F8 and/or Ar using the plasma-enhanced chemical vapour deposition method is reported. The chemical bonding structures of the films are analysed by x-ray photoelectron spectroscopy (XPS). In the case of the films deposited from the mixture with and without Ar, the configurations of F-Si-O-Si, Si-OH, Si-O-Si, C-CF and C-F are contained. However, there is also the C-C configuration in the film prepared from the mixture with Ar. Moreover, it is found that the photoelectron peaks of Si 2p, O 1s and F 1s for the film deposited from the feeding gas with Ar show the same shift of about 1eV toward high binding energy in comparison with those for the film prepared from the feeding gas without Ar. No evidence reveals the presence of an Si-C bond in the films. 相似文献
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Spectroscopic properties of Yb~(3+)-doped TeO_2–BaO–BaF_2–Nb_2O_5-based oxyfluoride tellurite glasses 下载免费PDF全文
A series of oxyfluoride glasses with the compositions of 75 mol% TeO2, 10 mol% Nb2O5,(15 mol%-x) BaO, x BaF2(x = 0 mol%, 5 mol%, 10 mol%, 15 mol%) doped with Yb2O3 were prepared by the melt-quenching method. Their emission cross-sections, fluorescence lifetimes, and gain properties were investigated by using the absorption spectra and the fluorescence decay curves. The results show that by substituting BaF2 for BaO, the emission cross-section decreases from 1.37 pm2 to 1.21 pm2, and the fluorescence lifetime increases from 0.71 ms to 0.96 ms. These properties indicate that this oxyfluoride tellurite glass may have potential uses as the Yb2O3-doped gain medium in a solid laser. 相似文献
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纳米碳酸锌的制备和热分解动力学参数的测定 总被引:3,自引:0,他引:3
Nanosized zinc carbonate was prepared in the droplet of nano-reactor based on microemusion. The influences of the concentration of the surfactant and reactant on the diameter of nanoparticles were studied and the kinetic pa-rameters of thermal decomposition reaction were determined. It can be shown from experimental results, the di-ameter of the droplet in the microemulsion which have dissolved reactant zinc nitrate and sal volatile is between 4.9nm and 7.7nm, 6.2nm and 12.4nm, respectively. Nanosized zinc carbonate prepared by the method of mi-croemusion has shown good dispersion, narrow distribution and light agglomeration. The particle size of nanosized zinc carbonate is between 5nm and 40nm, and its kinetic parameters of thermal decomposition reaction-activation energy E and reaction order n are 110kJ·mol-1 and 0.9, respectively. 相似文献
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采用水热法合成RUB-13分子筛,探讨了有机模板剂(OSDA)、硅源、晶化温度和水硅比等制备条件对RUB-13分子筛晶体结构的影响,考察了RUB-13分子筛在甲醇制烯烃(MTO)反应中的催化性能。结果表明,采用1,2,2,6,6-五甲基哌啶(PMP)为有机模板剂、白炭黑为硅源,在晶化温度为170℃的条件下,选择H2O/Si比为100和80时可分别合成出高纯度的低硅铝比(Si/Al=100)和高硅铝比(Si/Al=200)的RUB-13分子筛晶体,且晶粒呈棒状形貌。H-Al-B-RUB-13(Si/Al=200)分子筛用于催化甲醇制烯烃反应时,在400℃下表现出高的低碳烯烃选择性(C2=-5选择性达97. 8%,丙烯选择性为54. 5%),优于传统的H-SAPO-34和H-ZSM-5分子筛催化剂。 相似文献
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分别以拟薄水铝石、硅溶胶和磷酸为铝源、硅源和磷源,四乙基氢氧化铵为模板剂,采用两步水热晶化法合成出粒径为200~300 nm的纳米级SAPO-34分子筛.采用X射线衍射(XRD)、X射线荧光光谱(XRF)、29Si 、27Al、31P MAS NMR、SEM、BET和NH3-TPD等手段对合成的SAPO-34分子筛进行... 相似文献
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Reservoir computing has been considered as a promising intelligent computing paradigm for effectively processing complex temporal information. Exploiting tunable and reproducible dynamics in the single electronic device have been desired to implement the “reservoir” and the “readout” layer of reservoir computing system. Two-dimensional moiré materials, with an artificial lattice constant many times larger than the atomic length scale, are one type of most studied artificial quantum materials in ... 相似文献