نتایج جستجو برای: niobium compounds
تعداد نتایج: 229674 فیلتر نتایج به سال:
the main purpose of this research was to:1.develop a coking model for thermal cracking of naphtha.2.study coke inhibition methods using different coke inhibitors.developing a coking model in naphtha cracking reactors requires a suitable model of the thermal cracking reactor based on a reliable kinetic model.to obtain reliable results all these models shall be solved simultaneously.for this pu...
In this presented work, pure and holmium, niobium, holmium–niobium co-doped titanium dioxide nanopowders were synthesized by the sol–gel method. Their morphological, structural, optical, photocatalytic properties analyzed scanning electron microscopy, X-ray diffraction, UV–visible spectrophotometer. The activities of examined using ultraviolet light. results have shown that doping both with a s...
Title of dissertation: UNUSUAL ELECTRONIC TRANSPORT AND MAGNETISM IN TITANIUM OXIDE BASED SEMICONDUCTORS AND METALS Shixiong Zhang, Doctor of Philosophy, 2007 Dissertation directed by: Professor T. Venky Venkatesan Department of Physics The main objective of this thesis was to explore the structural, electrical, magnetic and optical properties of titanium based novel oxide thin films, such as t...
The data reported in this article are structural and physicochemical properties for bare and F, O, OH and CH3O-functionalized Nb n+1C n (n = 1, 2, 3 and 4) MXenes. The structural properties are presented as top views and side views from the X direction of the optimal structures of studied MXenes. The physicochemical properties include quantum capacitances, electrostatic potentials and electroni...
We have found that some of the usually poor dienophiles (2-cycloenones) can undergo Diels-Alder reaction at -78 degrees C with unusually high stereoselectivity in the presence of niobium pentachloride as a Lewis acid catalyst. A remarkable difference in reaction rates for unsubstituted and alpha- or beta-methyl substituted 2-cycloenones was also observed.
The electrical and magnetic properties were measured on polycrystalline samples of niobium diselenide intercalated with gadolinium atoms. dependences the resistance temperature point to a predominantly phonon scattering mechanism for charge carriers, while concentration are determined by increasing interstitial Gd x NbSe 2 (0≤ x≤0.33) studied in range 2-350 K fields up 70 kOe. Based results stu...
اسانس گیاهان (خشک شده در سایه)، tanacetum tenuisectum , tanacetum polycephalum به دو روش: 1- تقطیر با آب 2- برای اولین بار به روش میکرواستخراج فاز جامد در فضای فوقانی گرفته شد و به روش gc/ms مورد آنالیز و شناسایی واقع گردید. عمده ترکیبات اسانس سرشاخه های گلدار گیاه (tanacetum polycephalum) hydrodistillation % compounds 12.07 camphor 10.66 1, 8- cineole 9.57 chrysanthenyl acetate – t...
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