نتایج جستجو برای: spectroscopic methods
تعداد نتایج: 1913166 فیلتر نتایج به سال:
From hexanic extract of aerial parts of Peucedanum ruthenicum M. Bieb (Apiaceae) collected from Mazandaran province of Iran, four triterpenoids namely taraxasterol, y-taraxasterol, poriferasterol and b-sitosterol have been isolated by column chromatography, thin layer chromatography, and crystallization. Their structures were elucidated by spectroscopic methods (UV, IR, MS, 1H and 13C-N...
The aim of the present study is to synthesize the oxovanadium complex of the V3+ ion with isatin sciff bases. Spectroscopic methods have been used to confirm these models of complexation and to understand the structures of the species formed in methanolic solution. We also have isolated a complex of Vanadium (III) with isatin schiff bases in the solid phase.
the methods which are used to analyze microstrip antennas, are divited into three categories: empirical methods, semi-empirical methods and full-wave analysis. empirical and semi-empirical methods are generally based on some fundamental simplifying assumptions about quality of surface current distribution and substrate thickness. thses simplificatioms cause low accuracy in field evaluation. ful...
an anionic fe(ii) complex, (bmim)4[fe(cn)6] (where bmim is 1-butyl-3-methylimidazolium), was synthesized in ionic liquid [bmim][pf6] under reflux condition. the complex was characterized by elemental analysis and spectroscopic methods. the magnetite (fe3o4) nanoparticles were prepared by the hydrothermal and solvothermal (in ionic liquid [bmim][pf6]) methods from (bmim)4[fe(cn)6] as a precursor...
the rationale behind the present study is that particular learning strategies produce more effective results when applied together. the present study tried to investigate the efficiency of the semantic-context strategy alone with a technique called, keyword method. to clarify the point, the current study seeked to find answer to the following question: are the keyword and semantic-context metho...
Seven new donor/acceptor oligothiophenes 1-2 were synthesized by Stille coupling in moderate to good yields. Compounds 1-2 were completely characterized by the usual spectroscopic methods. In agreement with the electrochemical and the spectroscopic studies for this compounds the new derivatives prepared, can find application for manufacturing new materials with strong non-linear optical (NLO) p...
In this study, we combined different physico-chemical methods to show the effect of overheating on the quality of golden fry cooking oil. Those methods include spectroscopic methods such us 1H-NMR, 13C-NMR and FTIR. Results showed that both overheating and excessive reuse of golden fry cooking oil seriously affected its quality by increasing its density, viscosity and different indexes like ref...
Solvation is essential for protein activities. To study internal solvation of protein, site-directed mutagenesis is applied. Intrinsic fluorescent probe, tryptophan, is inserted into desired position inside protein molecule for ultrafast spectroscopic study. Here we review this unique method for protein dynamics researches. We introduce the frontiers of protein solvation, site-directed mutagene...
The electronic structures with spin-orbit effects of the zirconium nitride ZrN molecule are investigated by the methods of multireference single and double configuration interaction. The potential energy curves are calculated along with the spectroscopic constants for the lowest-lying 34 spin-orbit states Ω in ZrN. A good agreement is displayed by comparing the calculated spectroscopic constant...
in the area of vocabulary teaching and learning although much research has been done, only some of it has led to effective techniques of vocabulary teaching and many language learners still have problem learning vocabulary. the urge behind this study was to investigate three methods of teaching words. the first one was teaching words in context based on a traditional method of teaching that is,...
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