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71.
Maryam Abrishamkar Seyed Naser Azizi Jahan Bakhsh Raoof 《Monatshefte für Chemie / Chemical Monthly》2012,14(5):409-412
Abstract
Methanol is used as a fuel in the direct methanol fuel cell. Direct oxidation of methanol encounters large overvoltages at most unmodified electrode surfaces. The development of new procedures for electrocatalytic oxidation of methanol to decrease this overvoltage is therefore very desirable. In this paper, we report a new zeolite-modified carbon paste electrode based on Ni-ZSM-5 for methanol electrooxidation. Nanocrystallites of ZSM-5 (Si/Al of 50) with average particle size of 58 nm were synthesized using clear solutions at low temperature (90 °C) under atmospheric pressure. Ni(II) ions were incorporated into the zeolite by immersion of the modified carbon paste electrode with synthesized zeolite in a 1.0 M nickel chloride solution. Cyclic voltammetry showed that by using nano-sized zeolite, the oxidation current increased compared with that of micron-sized zeolite crystallites. 相似文献72.
Superparamagnetic tungstophosphoric acid supported on silica-encapsulated γ-Fe2O3 was used as an efficient catalyst for the direct oxidation of secondary amines to nitrones with hydrogen peroxide as the oxidant. The catalyst could be recycled up to four times without significant loss of activity. 相似文献
73.
It is well known by results of Golod and Shafarevich that the Hilbert 2-class field tower of any real quadratic number field, in which the discriminant is not a sum of two squares and divisible by eight primes, is infinite. The aim of this article is to extend this result to any real abelian 2-extension over the field of rational numbers. So using genus theory, units of biquadratic number fields and norm residue symbol, we prove that for every real abelian 2-extension over ? in which eight primes ramify and one of theses primes ≡ ?1 (mod 4), the Hilbert 2-class field tower is infinite. 相似文献
74.
Azizi Masitah Abdul Halim Isahak Wan Nor Roslam Wan Masdar Mohd Shahbudin Somalu Mahendra Rao Yarmo Mohd Ambar 《Research on Chemical Intermediates》2018,44(11):6787-6802
Research on Chemical Intermediates - Hydrogen is considered a promising energy carrier for the future, especially for clean energy generation via fuel cell technologies. Formic acid is one of the... 相似文献
75.
R. Pourgholi N. Azizi Y.S. Gasimov F. Aliev H.K. Khalafi 《Communications in Nonlinear Science & Numerical Simulation》2009,14(6):2664-2669
In this paper, we consider an inverse heat conduction problem (IHCP). A set of temperature measurements at a single sensor location inside the heat conduction body is required. Using a transformation, the ill-posed IHCP becomes a Cauchy problem. Since the solution of Cauchy problem, exists and is unique but not always stable, the ill-posed problem is closely approximated by a well-posed problem. For this new well-posed problem, the existence, uniqueness, and stability of the solution are proved. 相似文献
76.
Aouissi S. Mayer D. C. Ismaili M. C. Talbi M. Azizi A. 《Periodica Mathematica Hungarica》2020,81(2):250-274
Periodica Mathematica Hungarica - Let $$k=k_0(\root 3 \of {d})$$ be a cubic Kummer extension of $$k_0=\mathbb {Q}(\zeta _3)$$ with $$d>1$$ a cube-free integer and $$\zeta _3$$ a primitive... 相似文献
77.
The synthesis of zeolite ANA under static hydrothermal conditions was performed accompanied by an additional static and ultrasonic‐assisted aging of the reaction mixture prior to crystallization. The aging process was compared with stirring‐assisted aging, microwave‐assisted aging and syntheses without any aging. The influence of aging time on the crystallization time of zeolite ANA was investigated. The static and ultrasonic‐assisted aging can shorten the crystallization time of the ANA phase. Moreover, ultrasonic‐assisted aging leads to altered morphologies of the particles. The products were characterized by X‐ray diffraction (XRD) and scanning electron microscopy (SEM). 相似文献
78.
M. Taghinejad-Roudbaneh S.R. Ebrahimi S. Azizi P. Shawrang 《Radiation Physics and Chemistry》2010,79(12):1264-1269
The aim of the present study was to determine the impact of electron beam (EB) irradiation at doses of 15, 30 and 45 kGy on the nutritional value of canola meal. The phytic acid and total glucosinolate content of EB-irradiated canola meal decreased as irradiation doses increased (P<0.01). From in situ results, irradiation of canola meal at doses of 45 kGy decreased (P<0.05) the effective degradibility of crude protein (CP) by 14%, compared with an untreated sample. In vitro CP digestibility of EB-irradiated canola meal at doses of 15 and 30 kGy was improved (P<0.05). Electrophoresis results showed that napin and cruciferin sub-units of 30 and 45 kGy EB-irradiated canola meal were more resistant to degradation, compared with an untreated sample. Electron beam irradiation was effective in protecting CP from ruminal degradation and reducing antinutritional factors of irradiated canola meal. 相似文献
79.
This paper is a reply to a recent paper on the isomers of trisulfur oxides (Chem. Commun., 2005, 3712) where the accuracy of the CASPT2 method is called in question. We illustrate that their results are due to an inadequate choice of active orbitals. Some results for related O and S containing molecules are also presented to strengthen the argumentation. It is concluded that the CASPT2 method is accurate to at least 0.1 eV (2 kcal mol(-1)) for this type of systems. 相似文献
80.
An operationally simple and entirely green protocol for heteropoly acid (10 mg) catalyst conjugate addition of indoles and pyrrole to unsaturated carbonyl compounds and nitroalkene in water at ambient temperature in good to excellent yields has been developed. 相似文献