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Synthesis and characterization of yttrium-aluminum-iron and yttrium-cerium-iron citric complexes 被引量:2
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作者 N. Petrova D. Todorovsky1 +1 位作者 I. Mitov G. Tyuliev 《Journal of Rare Earths》 SCIE EI CAS CSCD 2008年第3期307-314,共8页
Fe-, Y-Fe-Al- and Y-Ce-Fe- citrates were synthesized in ethylene glycol (EG) medium under conditions similar to those used in the polymerized complex method. Their elemental composition, IR,^ 13C and ^1H NMR, X-ray ... Fe-, Y-Fe-Al- and Y-Ce-Fe- citrates were synthesized in ethylene glycol (EG) medium under conditions similar to those used in the polymerized complex method. Their elemental composition, IR,^ 13C and ^1H NMR, X-ray photoelectron and Mossbauer spectra were studied, and formulae describing their composition were proposed. The complexes contained EG bonded as adduct and ester with citric acid ligand and did not contain ligands with deprotonated alcoholic groups. The complexes consisted of agglomerated spheres, 0.7-3 μm in diameter. The local composition of the products was established by energy dispersive X-ray microanalysis. The comparison of the number of the ligands, their average electrical charge and the esterification degree of mono-, di- and trimetallic complexes proved the mixed-metal nature of the species studied. The thermal decomposition of the complexes was studied and a general scheme of the processes taking place was proposed. Highly crystalline, phase homogeneous YaFe4AlO12 was produced after heating the respective complex at 1000 ℃. Ce-doped yttrium-iron garnet, similarly prepared, contained traces of CeO2. 展开更多
关键词 GARNETS polymerized complex method Mossbauer spectroscopy thermal analysis nmr-spectroscopy rare earths
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Metabolomics for characterization of gender differences in patients infected with dengue virus
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作者 Nurul Shahfiza Hasnah Osman +2 位作者 Tang T.Hock Khozirah Shaari Abdel-Hamid Z Abdel-Hamid 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2015年第6期452-457,共6页
Objective:To determine the metabolic response associate with dengue infection based on human gender metabolic differences by means of ~1H NMR-spectrometry.Methods:The mid-stream urine collected from both male and fema... Objective:To determine the metabolic response associate with dengue infection based on human gender metabolic differences by means of ~1H NMR-spectrometry.Methods:The mid-stream urine collected from both male and female patients diagnosed with dengue fever at Penang General Hospital and fourty-three healthy individuals were analyzed with^1H NMR spectroscopy,followed by chemometric multivariate analysis.NMR signals which highlighted in the OPLS-DA S-plot were further selected and identified using Human Metabolome Database,Chenonix Profiler.Results:The results pointed out that NMR urine profiling was able to capture human gender metabolic differences that are important for the distinction of classes of individuals of similar physiological conditions;infected with dengue.Distinct differences between dengue infected patients versus healthy individuals and subtle differences in male versus female infected with dengue were found to be related to the metabolism of amino acid and tricarboxylic acid intermediates cycle.Conclusions:The ~1H NMR metabolomic investigation combined with appropriate algorithms and pattern recognition procedures,gave an evidence for the existence of distinct metabolic differentiation of individuals,according to their gender,modulates with the infection risk. 展开更多
关键词 Metabolomics DENGUE INFECTION nmr-spectroscopy
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Effect of Temperature on the Reaction of 2-(N-acetylamine)-3-(3,5-di-<i>tert</i>-butyl-4-hydroxyphenyl)-propionic Acid with Oxygen in an Alkaline Condition
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作者 A. A. Volodkin G. E. Zaikov +3 位作者 L. N. Kurkovskaja S. M. Lomakin I. M. Levina E. V. Koverzanova 《Advances in Chemical Engineering and Science》 2015年第3期262-269,共8页
Results of oxidation 2-(N-acetylamine)-3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid oxygen depend on temperature. At 55℃?- 60℃, 2,4-di-tert-butylbicyclo(4,3,1)deca-4,6-dien-8-(N-acetylamine)-3,9-dion-1-oxa i... Results of oxidation 2-(N-acetylamine)-3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid oxygen depend on temperature. At 55℃?- 60℃, 2,4-di-tert-butylbicyclo(4,3,1)deca-4,6-dien-8-(N-acetylamine)-3,9-dion-1-oxa is formed. The constitution is based on dates of spectrums 1Н and 13С NMR. At 95℃?- 97℃, mixtures of 2,4-di-tert-butylbicyclo(4,3,1)deca-4,6-dien-8-(N-acetylamine)-3,9-dion-1-oxa and of 6,8-di-tert-butyl-3-(N-acetylamine)spiro(4,5)deca-1-oxa-5,8-dien-2,7-dione are produced. Structures are calculated by the method of Hartrii-Foka. Values of enthalpies and of entropies allow to assume dynamic isomerism. 展开更多
关键词 2-(N-acetylamine)-3-(3 5-di-tert-butyl-4-hydroxyphenyl)-propionic Acid 6 8-di-tert-butyl-3-(N-acetylamine)spiro(4 5)deca-1-oxa-5 8-dien-2 7-dione Oxidation by OXYGEN 2 4-Di-tert-butylbicyclo(4 3 1)deca-4 6-dien-8-(N-acetylamine)-3 9-dion-1-oxa nmr-spectroscopy
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