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71.
Galina V. Benemanskaya Sergey V. Ivanov Mikhail N. Lapushkin 《Solid State Communications》2007,143(10):476-480
We report on the observation of new phenomena that arise under Cs adsorption on n-GaN(0001) and n-InGaN(0001) surfaces. First, an extremely highly quantum efficient photoemission has been found by excitation with visible light in the transparency region of GaN and InGaN. The photoemission is revealed to appear due to the formation of an electron accumulation layer in the vicinity of the surfaces. Second, a large variety of band bending and potential wells are provided by the Cs coverages. The accumulated charge density at the n-InGaN surface is much stronger than that at the n-GaN surface. Third, a new effect is revealed, namely, the appearance of an oscillation structure in the spectral dependences of the threshold photoemission. A model concept is proposed for photocurrent oscillations that takes into account the formation of an accumulation layer and the multiple-beam interference in parallel-sided GaN or InGaN samples. 相似文献
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A modification of the multigrid method for the solution of linear algebraic equation systems with a strongly nonsymmetric matrix obtained after difference approximation of the convection-diffusion equation with dominant convection is proposed. Specially created triangular iterative methods have been used as the smoothers of the multigrid method. Some theoretical and numerical results are presented. 相似文献
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Tao Song Corey N. W. Lam Dominic C. M. Ng Galina Orlova Julia Laskin De-Cai Fang Ivan K. Chu 《Journal of the American Society for Mass Spectrometry》2009,20(6):972-984
The dissociation of [CuII(L)His]•2+ complexes [L=diethylenetriamine (dien) or 1,4,7-triazacyclononane (9-aneN3)] bears a strong resemblance to the previously reported behavior of [CuII(L)GGH]•2+ complexes. We have used low-energy collision-induced dissociation experiments and density functional theory (DFT) calculations
at the B3LYP/6-31+G(d) level to study the macrocyclic effect of the auxiliary ligands on the formation of His•+ from prototypical [CuII(L)His]•2+ systems. DFT revealed that the relative energy barriers of the same electron-transfer (ET) dissociation pathways of [CuII(9-aneN3)His]•2+ and [CuII(dien)His]•2+ are very similar, with the ET reactions of [CuII(9-aneN3)His]•2+ leading to the generation of two distinct His•+ species; in contrast, the proton transfer (PT) dissociation pathways of [CuII(9-aneN3)His]•2+ and [CuII(dien)His]•2+ differ considerably. The PT reactions of [CuII(9-aneN3)His]•2+ are associated with substantially higher barriers (>13 kcal/mol) than those of [CuII(dien)His]•2+. Thus, the sterically encumbered auxiliary 9-aneN3 ligand facilitates ET reactions while moderating PT reactions, allowing the formation of hitherto nonobservable histidine
radical cations. 相似文献
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Nina Perkas Michael Shuster Galina Amirian Yuri Koltypin Aharon Gedanken 《Journal of polymer science. Part A, Polymer chemistry》2008,46(5):1719-1729
Silver nanoparticles were immobilized on the surface of polypropylene (PP) porous beads by an ultrasound‐assisted reduction method. The structure and properties of the silver–PP composite were characterized with XRD, TEM, HRSEM, EDX, XPS, and Raman spectroscopy. Water‐soluble polymers such as PEG, PVA, and PVP were used as stabilizing agents for preventing the agglomeration of the silver nanoparticles. With PVP, a homogeneous distribution of silver nanocrystals, 50 nm in size, on the PP surface was achieved. The mechanism proposed for the silver anchoring to the inert polymer accounts for a localized melting of the PP. The beads of the silver PP composite demonstrated good stability and high antibacterial activity. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1719–1729, 2008 相似文献
80.
Sergey Miltsov Vladimir Karavan Alexandr Misharev Galina Starova Julian Alonso-Chamarro Mar Puyol 《Tetrahedron letters》2017,58(34):3353-3357
meso-Bromosubstituted indodicarbocyanine dyes produce dimeric molecules, together with the debrominated species, under acid catalysis. The relationship between the dimerization and hydrodebromination routes depends on the aryl substitution of the dyes. A possible reaction mechanism is also proposed. 相似文献