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11.
Umesh Balakrishnan Nallamuthu Ananthi Sakthivel Tamil Selvan Ravindra Pal Dr. Katsuhiko Ariga Dr. Sivan Velmathi Dr. Ajayan Vinu Dr. 《化学:亚洲杂志》2010,5(4):897-903
The immobilization of chiral oxazaborolidine complex in the well‐ordered mesochannels of SBA‐15 is demonstrated by a postsynthetic approach using 3‐aminopropyltriethoxysilane as a reactive surface modifier. The immobilized catalysts are characterized by various techniques, such as XRD, nitrogen adsorption, HRSEM, UV/Vis diffuse reflectance spectroscopy, and FTIR spectroscopy. The catalysts are used for the enantioselective reduction of aromatic prochiral ketones. The activity of the chiral oxazaborolidine complex immobilized SBA‐15 catalysts is also compared with that of the pure chiral oxazaborolidine complex, which is a homogeneous catalyst. It is found that the activity of the chiral complex immobilized SBA‐15 heterogeneous catalyst is comparable with that of the homogeneous catalyst. 相似文献
12.
K. Karthikeyan S. Amaresh D. Kalpana R. Kalai Selvan Y.S. Lee 《Journal of Physics and Chemistry of Solids》2012,73(2):363-367
Hierarchical structured Co-doped SnO2 nanoparticles are prepared by a low temperature hydrothermal process. The structural and surface morphologies of the SnO2 and Sn1?xCoxO2 nanoparticles are studied by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The Sn1?xCoxO2 nanoparticles form with a tetragonal rutile structure during the hydrothermal process without further calcination. The pseudocapacitance behavior of the Sn1?xCoxO2 nanoparticles is characterized by cyclic voltammetry (CV) in 1.0 M H2SO4 electrolyte. The specific capacitance (SC) is found to increase with an increase in cobalt content. A maximum SC of 840 F g?1 is obtained for a Sn0.96Co0.04O2 composite at a 10 mV s?1 scan rate. 相似文献
13.
M. Kanagaraj A. Krzton‐Maziopa G. Kalai Selvan E. Pomjakushina K. Conder S. Weyeneth R. Puzniak S. Arumugam 《固体物理学:研究快报》2013,7(3):218-220
We report on the effect of external pressure on the superconducting transition temperature (Tc) of as‐grown and thermally treated single crystals of superconducting iron chalcogenide Rb0.85Fe1.9Se2. The superconducting transition temperature of 27.1 K at ambient pressure for the as‐grown sample was found to increase up to 33.2 K for the sample annealed for 3 h at 215 °C in vacuum. An increase of Tc up to 28.2 K was observed for the as‐grown sample at a pressure of 0.83 GPa. For all the studied crystals, annealed in the temperature range between 215 °C and 290 °C, the external pressure seems to decrease the superconducting transition temperature and a negative pressure coefficient of Tc was observed. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
14.
Prathibha T. Selvan B. Robert Hemalatha V. Suba M. Amutha Chandra Swaroop Shaji Dinu Vijay Soja K. Sundararajan K. Ramanathan N. 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(5):2383-2391
Journal of Radioanalytical and Nuclear Chemistry - A spectrophotometric method, circumventing interference from F− ions, during estimation of Zr in U-Zr alloy fuel, has been developed.... 相似文献
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R. Kalai Selvan C. O. Augustin M. I. Oshtrakh O. B. Milder V. A. Semionkin 《Hyperfine Interactions》2007,179(1-3):33-38
A series of (CuFe2O4)1???x (SnO2) x nanocomposites (x = 0, 1, 5, 10, 20 wt.%) have been prepared by urea–nitrate combustion method. The room temperature Mössbauer spectra of CuFe2O4 and (CuFe2O4)0.99(SnO2)0.01 contained two sextets while remaining samples contained at least four sextets with additional doublet indicating the presence of paramagnetic phase. The variations of isomer shift, quadruple splitting and magnetic hyperfine field values were found with the addition of SnO2. 相似文献
18.
B.K. Nayak B. Eaton J.A.A. Selvan J. McLeskey M.C. Gupta R. Romero G. Ganguly 《Applied Physics A: Materials Science & Processing》2005,80(5):1077-1080
Semiconductor laser (=805 nm) crystallization of hydrogenated amorphous silicon (a-Si:H) deposited on a low-cost fluoride-doped tin-oxide-coated glass substrate is demonstrated. X-ray diffraction confirms that the structure of the polycrystalline silicon thus formed shows (111), (220), and (311) peaks. A sharp Raman peak at 520 cm-1 further confirms the crystallization. Atomic force microscope images of a Secco-etched laser-treated sample reveal the granular structure of the poly-Si. Grains as big as 10 times the film thickness are readily obtained and sample as thick as 5000 Å is easily crystallized. The method can be extended to films with a thickness of several microns. PACS 42.55.Px; 42.62.Cf; 81.05.Gc 相似文献
19.
B. Selvan K. Ramachandran B. C. Pillai D. Subhakar 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,61(3):663-675
Temperature of the substrate during plasma heating and spraying plays an
important role on quality of the substrate and coating. In this study a
three dimensional numerical model is developed to simulate the Ar-N2
plasma jet and conjugate heat transfer between plasma and substrate. The
influencing of operating parameters on thermal flux from the plasma to the
substrate and substrate temperature are discussed. Transient simulations are
carried out to predict the substrate temperature with heating time. The arc
current, gas flow rate, stand-off distance, substrate material and
environment around the substrate significantly affect the thermal flux to
the substrate. Heat flux to the substrate cannot be neglected in the coating
built-up models. Present model is validated by comparing the results of
present model with previous predictions and measurements. 相似文献
20.
R. Kalai Selvan A. Gedanken P. Anilkumar G. Manikandan C. Karunakaran 《Journal of Cluster Science》2009,20(2):291-305
We report herein on an efficient sonochemical method for the synthesis of rare earth orthovanadate nanorods/nanoparticles/nanospindles,
(general formula RVO4; R = La, Ce, Nd, Sm, Eu and Gd). TGA, XRD, FTIR, Raman, UV–Vis, and TEM studies are employed for their characterization and
for understanding their morphologies. In order to vary the textural properties of the rare earth vanadates, two surfactants,
polyethylene glycol (PEG) and amphiphilic triblock copolymer Pluronic P123, are chosen in the preparation. While the sonochemical
synthesis in the presence of PEG results in the formation of nearly spherical nanoparticles of LaVO4, CeVO4, SmVO4 and EuVO4, the same technique yields nanorods and nanospindles of NdVO4 and GdVO4, respectively. When P123 is used as the surfactant, the morphologies of RVO4 are strikingly different, and in most cases nanorods and nanospindles are formed. The photocatalytic activities of the rare
earth orthovanadate have been evaluated by studying the degradation of methylene blue, and CeVO4 seems to be the best catalyst in the heterogeneous photolysis. The electrocatalytic activity of the vanadates has been examined
by studying the hydrogen evolution reaction using a linear sweep voltammogram technique in 1 M of a H2SO4 solution. GdVO4 seems to be the best electrocatalyst.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献