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91.
Occurrence and prevention of photodissolution at the phase junction of magnetite and titanium dioxide 总被引:12,自引:0,他引:12
Donia Beydoun Rose Amal Gary Low Stephen McEvoy 《Journal of molecular catalysis. A, Chemical》2002,180(1-2):193-200
A stable magnetic photocatalyst was prepared by coating a magnetic core with a layer of photoactive titanium dioxide. A direct deposition of titanium dioxide onto the surface of magnetic iron oxide particles proved ineffective in producing a stable magnetic photocatalyst, with high levels of photodissolution being observed with these samples. This observed photodissolution is believed to be due to the dissolution of the iron oxide phase, induced by the photoactive the titanium dioxide layer due to electronic interactions at the phase junction in these magnetic photocatalysts. The introduction of an intermediate passive SiO2 layer between the titanium dioxide phase and the iron oxide phase inhibited the direct electrical contact and hence prevented the photodissolution of the iron oxide phase. The magnetic photocatalyst is for use in slurry-type reactors from which the catalyst can be easily recovered by the application of an external magnetic field. 相似文献
92.
Amal E. M. Khaleel 《Monatshefte für Chemie / Chemical Monthly》2002,133(2):183-187
Summary. Three new 4-quinolinone alkaloids (5,6-dimethoxy-2-(3-methoxyphenyl)-1H-quinolin-4-one, 5,6-dimethoxy-2-(3,4-dimethoxyphenyl)-1H-quinolin-4-one, 5,6-dimethoxy-2-(2,5,6-trimethoxyphenyl)-1H-quinolin-4-one) were isolated from the leaves of Casimiroa edulis Llave et Lex (Rutaceae) cultivated in Egypt. Their structures were determined by UV/Vis, IR, 1H and 13C NMR, and EI mass spectroscopy. The alkaloids were also detected in the kernels of the seeds.
Received May 28, 2001. Accepted (revised) July 24, 2001 相似文献
93.
The palladium-catalyzed formal [3+2] cycloaddition reaction of alkylidenecyclopropanes with 1,2-diazines proceeded smoothly to give the corresponding 5-azaindolizine derivatives in good to allowable yields. For example, in the presence of 5 mol % of Pd(PPh(3))(4), the reaction of 1-propylhexylidenecyclopropane with phthalazine or with pyridazine proceeded at 120 degrees C without solvent, and the corresponding 2-(1-butylpentyl)pyrrolo[2,1-a]phthalazine or 6-(1-butylpentyl)pyrrolo[1,2-b]pyridazine was obtained in 61% or 49% yield, respectively. 相似文献
94.
95.
The Fokker-Planck equation in one dimension has been solved for a system in a periodic potential and linearly perturbed by a time- and space- varying external electric field. The solution is not exact, but we believe it is less approximate than any attempted previously on this problem. We have calculated the frequency and wave-vector dependent mobility and discussed its behaviour in some limiting cases.The application of our model to various physical situations is discussed. 相似文献
96.
Amal K. Das 《Solid State Communications》1978,27(12):1445-1447
The solution of the sine-Gordon equation for a medium is studied in a simplified “quasi-linear” approximation. Several aspects of this approximation are explored and compared with other approximate solutions for the sine-Gordon soliton. 相似文献
97.
Naji Al Dahoudi Amal AlKahlout Sabina Heusing Petra Herbeck-Engel Rudolf Karos Peter Oliveira 《Journal of Sol-Gel Science and Technology》2013,67(3):556-564
Crystalline indium doped zinc oxide (IZO) nanopowders were synthesized using hydrothermal treatment processing. Increasing the doping ratio of indium in the zinc oxide significantly influences the phase structure and shape of the nanopowders resulting in nanorod to nanoparticulate morphologies. As the doping profile increases, the crystallite size decreases, the band gap energy blue shifts and the specific surface area increases (measured by BET method). Additionally Raman spectroscopy exhibited shifts of several peaks, as well as revealed new peaks, confirming the substitution of indium ions within the zinc oxide lattice sites. An IZO suspension made of IZO nanoparticles (In/Zn = 3 atm.%) with a zeta potential greater than 30 mV at pH = 6 was successfully spin-coated on glass substrates for to make transparent conductive coatings evincing sheet resistances as low as 35 kΩ□ (ρ = 4.9 × 10?3 Ω m,) with transmission in the visible range as high as 90 %. 相似文献
98.
Amal M.F. Al-Aboudi Barakat E. Abu-Irmaileh Firas F. Awwadi Monther A. Khanfar 《Natural product research》2015,29(2):102-108
Three new seco-ursadiene triterpenoids 1–3 together with 11 known compounds were isolated from Salvia syriaca of Jordanian origin. The compounds were identified by using NMR spectroscopy including extensive 2D NMR experiments and mass spectrometry. The structure of compound 3 was confirmed by X-ray crystallography, and the information thus obtained was used to confirm the stereochemistry of compounds 1 and 2. This is the second report of 17,22-seco-17(28),12-ursadien-22-oic acids. 相似文献
99.
100.