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101.
采用双控体积巨正则系综分子动力学(DCV-GCMD)方法, 用二维狭缝代替传统的一维狭缝构建膜孔模型研究了温度对氮氧纯气体及其混合物在碳膜内的渗透特性, 探讨了氮氧分离机理. 提出了一种新的计算二元混合气体中各组分通量和分离系数的方法, 即模拟中引入迭代, 解决了前人忽略低压侧气体组成和压力影响的问题. 试验结果表明: 当氮氧以纯气体的形式分别透过碳膜时, 二者均遵循Knudsen扩散方式, 且低温下氮气具有较大的渗透性质; 而当二者以混合物的形式一起透过碳膜时, 低温下二者之间存在竞争吸附, 孔宽对气体的渗透影响显著, 尤其是膜孔较小的时候, 分子筛效应控制氮氧分离; 高温下吸附影响不显著. 相似文献
102.
R. A. Manzhos Yu. M. Maksimov B. I. Podlovchenko 《Russian Journal of Electrochemistry》2005,41(8):832-837
Transients of the open-circuit potential, which are observed during the interaction of formic acid with preliminarily adsorbed oxygen (Oads) on a Pt/Pt electrode in 0.5 M H2SO4, are measured. It is established, by means of the method of cathodic potentiodynamic pulses, that the slowest interaction of formic acid with Oads occurs in the region of large coverages of the electrode surface by oxygen (θO ∼1–0.8). A presumption is put forward that the process rate in this region is defined by a direct reaction of Oads with molecules of formic acid from the bulk solution. It is shown that the interaction of formic acid with Oads in the region of intermediate coverages (θO ∼ 0.8–0.2) proceeds via a mechanism of “conjugated reactions.” Transients of the open-circuit potential for formic acid are compared to transients for carbon monoxide obtained in analogous conditions. The substantially shorter overall time of potential decay in the case of CO (at the same concentrations) is caused by a faster reaction of CO with adsorbed oxygen in the region of large θO. The difference is explained by assuming that the HCOOH adsorption as opposed to CO bears a dissociative character.__________Translated from Elektrokhimiya, Vol. 41, No. 8, 2005, pp. 936–942.Original Russian Text Copyright © 2005 by Manzhos, Maksimov, Podlovchenko. 相似文献
103.
Summary Multipulse experiments reveal qualitative and quantitative, time-resolved information about the interaction of N2O with ZSM-5 type zeolites under conditions of catalytic applications, like the mechanism of N2O decomposition, amount and reactivity of an atomic surface oxygen species. 相似文献
104.
Three new cobalt complexes were synthesized by solid-state reaction at room temperature. It was found that one mole of complex reacted with two moles of oxygen at room temperature. And the oxygenated complexes [Co·(L1)2·2O2](NO3)2·2H2O (L1=N,N′-bis(4-hydroxyl-3-methoxy-benzyl)-triethylenetetramine), [Co·(L2)2·2O2](NO3)2 ·2H2O (L2=N,N′-bis(4-hydroxyl-benzyl)-triethylenetetramine) and [Co·L3·2O2](NO3)2·2H2O (L3=N,N′-bis(2-hydroxyl-benzyl)-triethylenetetramine) were obtained and characterized by elemental analysis, IR spectra, 1H NMR, TG/DTA, UV-Vis and molar conductance. The coordinated oxygen contents in the oxygenated complex were also determined by weight method. It was found that one O2 molecule coordinated to the Co ion and formed superoxo type oxygenated complex. 相似文献
105.
《Arabian Journal of Chemistry》2020,13(12):8848-8887
Phthalocyanine (Pc) complexes are an important class of dyes with numerous (e.g., biological, photophysical, and analytical) applications. Among the methods used to improve the properties of these complexes, one should mention the introduction of different substituents, variation of the central metal ion, ligand exchange, and conjugation to nanomaterials (e.g., carbon-based nanomaterials and metal nanoparticles (NPs)). This work briefly reviews Pc complex conjugation to Ag and Au NPs, highlights the different NP shapes, and discusses the diversity of conjugation approaches. Moreover, the use of UV–Vis spectroscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, atomic force microscopy, dynamic light scattering and Fourier transform infrared spectroscopy to characterize Pc-NP hybrids is summarized. The effect of conjugation on Pc photo-physicochemical properties (fluorescence, singlet oxygen generation, triplet state formation, and optical limiting behavior) is discussed, and future perspectives for the synthesis and applications of new hybrids are provided. 相似文献
106.
用热聚法固定指示剂的光纤氧气传感器研究 总被引:5,自引:0,他引:5
采用热聚法将甲叉双丙烯酰胺(MBBA)聚合并共价交联在硅烷化的玻璃微珠上 ,同时将指示剂Ru(Ⅱ)-邻啡咯啉配合物物理包埋于聚合物中,研制了一种基于 荧光猝灭原理的光纤氧气传感器,采用NaHSO_3-O_2-MnSO_4体系引发MBBA水溶液热 聚合后应,通过确定NaHSO_3,MnSO_4,MBBA和Ru(phen)_3Cl_2的最佳反应浓度以及 玻璃微珠的尺寸,优化了聚合反应条件,改善了指示剂的固定效果,制备了性能较 好的传感器探头,该传感器的检测下限为5×10~(-6)(V/V),响应时间为10s该传感 器连续工作50min,重复性标准偏差为±1%。 相似文献
107.
A New High Temperature Form of TiO: H? TiO Single crystals of a high temperature form of TiO (H? TiO) were prepared above 3 000°C by CO2-LASER technique. They crystallize with a hitherto unobserved crystal structure of oxides with titanium in the oxidation state two, isotypic to tungsten carbide with Ti2+ in a trigonal prismatic surrounding by oxygen. Space group D–P6 m2, a = 3.0310, c = 3.2377 Å, Z = 1. 相似文献
108.
用TPD-MS和TPR技术研究了Mn-O/γ-Al2O3和Mn-O/ZrO+γ-Al2O3催化剂中表面氧的脱附、还原性能和再生氧化恢复性能,并用XRD对催化剂的固相结构进行了表征。结果表明,Mn-O/γ-Al2O3或Mn-O/ZrO2+γ-Al2O3催化剂上存在MnO2、Mn2O3和少量Mn3O4物种。ZrO2的存在不影响Mn-O/γ-Al2O3的TPR的TPD的特征峰,但使MnO2的量明显增加, 相似文献
109.
Aquino AJ Tunega D Haberhauer G Gerzabek MH Lischka H 《Journal of computational chemistry》2003,24(15):1853-1863
Hydrogen-bonded interactions between local defect structures on broken clay surfaces modeled as molecular clusters and the organic molecules acetic acid, acetate, and N-methylacetamide (NMA) have been investigated. Density functional theory and polarized basis sets have been used for the computation of optimized interaction complexes and formation energies. The activity of the defect structures has been characterized as physical or chemical in terms of the strength of the hydrogen bonds formed. Chemical defects lead to significantly enhanced interactions with stronger hydrogen bonds and larger elongation of OH bonds in comparison to the physical defects. The type of interaction with the defect structure significantly influences the planarity of the model peptide bond in NMA. Both cases, enhancement of the planarity by increase of the CN double bond character and strong deviations from planarity, are observed. 相似文献
110.
Marta Teijeira 《Tetrahedron letters》2005,46(35):5889-5892
We describe an efficient new approach for the synthesis of a chiral butenolide that is based on the oxidation of a chiral furan ring with singlet oxygen in the presence of Hünig’s base, followed by Luche reduction and in situ lactonization. 相似文献