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101.
F. M. Radwan A. M. Abd El-Hameed M. R. Mahmoud R. B. Fahim 《Journal of Thermal Analysis and Calorimetry》1987,32(3):883-891
The parent material, ammonium permanganate, was carefully decomposed in air at 120°. The product, referred to as the starting material (SM), was then subjected to thermal treatment in air for 5 hr in the temperature range 150–1200°. Chemical analysis of SM indicated that the main decomposition product of NH4MnO4 was Mn2O3, together with MnO2, NH4NO3, H2O and O2. Mn3O4 started to form at 900°. The infrared spectra of various calcination products revealed the retention of NH
4
+
in the lattice structure up to 300°, and reflected the presence of excess oxygen as coordinated O
2
–
. The TG, DTA and IRA results on SM supported the chemical analysis data. X-ray analysis was carried out for phase identification and to follow transformations and the formation of a solid solution between MnO2 and Mn2O3.
Paper presented at the World Conference on Thermal Analysis, Madeira (Portugal), 1986. 相似文献
Zusammenfassung Die Muttersubstanz, Aramoniumpermanganat, wurde in Luft bei 120° vorsichtig zersetzt. Das dabei erhaltene Ausgangsmaterial (SM) wurde danach in Luft 5 Stunden im Temperaturbereich von 150–1200° thermisch behandelt. Die chemische Analyse von SM ergab, daß als Hauptprodukt der Zersetzung von NH4MnO4, Mn2O3 auftritt neben MnO2, NH4NO3, H2O und O2. Die Bildung von Mn3O4 beginnt bei 900°. Aus Infrarotspektren verschiedener Kalzinierungsprodukte ist ersichtlich, daß in der Gitterstruktur NH 4 + bis 300° zurückgehalten wird und überschüssiger Sauerstoff in Form von koordiniertem O2 vorliegt. Die Ergebnisse der TG-, DTA- und IRA-Untersuchungen von SM bestätigen Daten der chemischen Analyse. Mittels Röntgenanalyse wurden die Phasen identifiziert und der Verlauf der Phasenübergänge und der Bildung einer festen Lösung zwischen MnO2 und Mn2O3 verfolgt.
120°. , , 5 150–1200°. , , , , . 900° Mn3O4. 300° - O 2 – . , . , .
Paper presented at the World Conference on Thermal Analysis, Madeira (Portugal), 1986. 相似文献
102.
The study of the oxidation of low density polyethylene is carried out under fluidized conditions in air and ozone. Special attention is paid to the formation of peroxides and hydroperoxides. Their production is optimized according to various parameters (temperature, time, quantity of ozone, flow of the gaseous current) using an experimental design method. Peroxides and hydroperoxides are titrated by a colorimetric method using diphenylpicrylhydrazyl as reagent. A correlation between i.r. carbonyl ratio and the yield of peroxides has been established. 相似文献
103.
104.
M. M. Ghorab N. M. H. Taha M. A. A. Radwan N. E. Amin M. A. Shehab I. M. I. Faker 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):2891-2905
This article describes the synthesis of some novel sulfone bis-compounds bearing the biologically active thioether 3–6 ; thioureido 7, 8, 15, 16; triazole 10, 11; thiosemicarbazido 9, 12, 13; and 1,3,4-thiadiazole 14, 17 moieties starting with 4,4′-diisothiocyanato-1,1-diphenylsulfone 2. The structures of newly synthesized compounds were confirmed by elemental analysis, IR, 1 H-NMR and mass spectral data. Compound 3 was found to be the most active compound against Escherichia coli. Also, compound 15 acted as potent cytotoxic agent. 相似文献
105.
Shih‐Sheng Wang Yu‐Hui Chen Jiun‐Yang Chang Tsong‐Long Hwang Chung‐Hsiung Chen Ashraf Taha Khalil Ya‐Ching Shen 《Helvetica chimica acta》2009,92(10):2092-2100
Chemical investigation of the Taiwanese gorgonian coral Junceella juncea resulted in the isolation of four new briarane‐type diterpenoids, juncenolides H, I, J, and K ( 1 – 4 ). Their structures were determined on the basis of spectroscopic analysis, especially 1‐ and 2D‐NMR. The inhibitory effects of compounds 1 – 4 on superoxide‐anion generation and elastase release by human neutrophils were evaluated. 相似文献
106.
Seraj Faiza Kanwal Khan Khalid Mohammed Khan Ajmal Ali Muhammad Khalil Ruqaiya Ul-Haq Zaheer Hameed Shehryar Taha Muhammad Salar Uzma Perveen Shahnaz 《Molecular diversity》2021,25(1):143-157
Molecular Diversity - Novel ibuprofen derivatives 1–19 including ibuprofen hydrazide 1, and substituted thiourea derivatives 2–19 were synthesized and characterized by EI-MS, FAB-MS,... 相似文献
107.
Aziz Taha Javaid Saba Aziz Asim Sadiq M. A. 《Journal of Thermal Analysis and Calorimetry》2021,143(2):985-1002
Journal of Thermal Analysis and Calorimetry - The fully developed boundary layer flow and heat transfer model of an unsteady, incompressible, electrically conducting, optically thick and... 相似文献
108.
Deeb Marji Khamis Abbas Riyadh Saymeh Ziyad Taha 《Journal of inclusion phenomena and macrocyclic chemistry》1999,34(1):49-56
A conductance study of the interaction between substituted ammonium ions with three crown ethers in aqueous solution has been carried out at different temperatures. The formation constants of the 1 : 1 complexes at various temperatures were determined from the molar conductance-mole ratio data and found to vary in the order 18C6 > 15C5 > 12C4 for the same salt and with the same crown, the formation constants vary in the order (C2H5)3NHCl > (C2H5)4NBr > (CH3)3NPhI.The enthalpy and entropy of complexation were determined from the temperature dependence of the formation constants. The results indicate that the complexation process is enthalpy unfavored and entropy favored. The influence on the thermodynamic data for different parameters such as cavity size of crown ethers and nature of salt are discussed. 相似文献
109.
Mohammad Nooredeen Abbas Abdel Latief A. Radwan Naglaa M. Nooredeen Mahmoud A. Abd El-Ghaffar 《Journal of Solid State Electrochemistry》2016,20(6):1599-1612
A novel solid-state selective sensor for mono-hydrogen phosphate (HPO4)?2 based on copper monoamino phthalocyanine (CuMAPc) ionophore covalently attached to poly (n-butyl acrylate) (PnBA) has been developed and potentiometrically evaluated. The all solid-state sensor was constructed by the application of a thin film of a polymer cocktail containing a CuMAPc–PBDA ionophore and benzyl-dimethylhexadecyl ammonium chloride (BDMHAC) as a lipophilic cationic additive onto a gold electrode pre-coated with the conducting polymer poly (3,4-ethylenedioxythiophene) (PEDOT) as an ion and electron transducer. The sensor with 14.31 % of CuMAPc-PnBA (ionophore II) exhibited a good selectivity for (HPO4)?2. The thus constructed sensor discriminated many anions, including F?, Cl?, Br?, I–, CH3COO?, NO3 ?, ClO4 ?, and SO4 2?. The potentiometric response of the phosphate selective electrode was found to be independent of the pH of sample solution in the range 6–9. The sensor showed a Nernstian slope of ?29.8 ± 0.3 mV conc.?1 decade?1 with linear range of 4.0 × 10?9–1.0 × 10?2 mol L?1 and detection limit of 1.0 × 10?9 mol L?1 at pH 8.0. The proposed phosphate sensor has been utilized as a detector for the flow injection potentiometric determination of phosphate in different water samples at the nanomolar concentration range. 相似文献
110.
Khalifa N. M. Haiba M. E. Taha M. M. Al-Omar M. A. 《Russian Journal of General Chemistry》2019,89(2):319-323
Russian Journal of General Chemistry - Novel polycyclic compounds, 1-pyrene-based pyridone derivatives, are synthesized by treatment of pyrenyl acetohydtazide with several arylidenemalononitriles... 相似文献