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41.
Summary Tri-and quadri-dentate Schiff bases have been synthesized from the reaction of dehydroacetic acid with diamines, aminoacids, aminophenols and aminoalcohols. The copper(II) and some nickel(II) and palladium(II) chelates of these ligands as well as copper(II) complexes of bidentate Schiff bases of dehydroacetic acid with anilines have been prepared and characterised by electronic, i.r. and n.m.r. spectral measurements and magnetic moments. 相似文献
42.
B. Subramanian R. Ananthakumar M. Jayachandran 《Crystal Research and Technology》2011,46(12):1273-1282
TiN/NbN multilayer coatings were deposited with various substrate temperatures by DC reactive magnetron sputtering method onto Si (111) and glass substrates. The effect of substrate temperature on the structural and optical properties of TiN/NbN multilayers was investigated by X‐ray diffraction, X‐ray photoelectron spectroscopy, Field emission scanning electron microscopy and Photoluminescence measurements. The composition was analyzed by X‐ray photoelectron spectroscopy. X‐ray diffraction results showed that the layers crystallized in cubic structure for TiN and hexagonal structure for NbN. It was found that grain size increased with increase in substrate temperature. The surface morphology of the TiN/NbN thin films showed a dense and smooth surface with substrate temperature upto 200 °C but after 300 °C, the grains became larger and coarse surface was observed. The TiN/NbN multilayer coatings exhibited the characteristic peaks centered at 180, 210 and 560 cm‐1. Red band emission peaks were observed in the wavelength range of 700‐710 nm. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
43.
A. Moses Ezhil Raj V. Bena Jothy C. Ravidhas T. Som M. Jayachandran C. Sanjeeviraja 《Radiation Physics and Chemistry》2009,78(11):914-921
Energetic 1.5 MeV Li+ irradiation on MgO thin film surfaces for fluences 1013, 1014 and 1015 ions/cm2 led to radiation damage that altered the grain size from 29 to 9 nm and the internal stress. Optical absorption bands at 5.0, 3.49, 2.16 and 1.27 eV revealed, respectively, the presence of, oxygen vacancies, anion divacancies and trapped-hole centers. DC electrical conductivity of was increased by three orders of magnitude at room temperature as the fluence was increased to 1015 ions/cm2. 相似文献
44.
A. Moses Ezhil Raj D. Deva Jayanthi V. Bena Jothy M. Jayachandran C. Sanjeeviraja 《Crystal Research and Technology》2008,43(12):1307-1313
Single crystals of barium oxalate monohydrate (BaC2O4.H2O, BOM) were grown in pure form by controlled diffusion of Ba2+ using the gel technique at different temperatures. Starting from aqueous Ba2+ chloride (BaCl2) and acetic acid (C2H2O4) in gel, this method offers a low‐cost and an easiest alternative to other preparation methods for the production of barium oxalate bulky single crystals. The optimal conditions for the growth of BOM crystals in silica gel were found by investigating different growth parameters such as gel pH, gel aging and crystallization temperature. Irrespective of all such crystallization environments, growth rate of the crystals were initially less and then exhibited supersaturation effect leading to non‐linearity. Gel aging and temperature has profound effect on nucleation density that resulted less number of crystals of maximum size in the gel matrix. Perfect single crystals were grown on gels of higher pH. The macropore morphology and porosity was controlled by changing age of the gel. It has been found that temperature has a fabulous effect in controlling the nucleation density by altering the supersaturation conditions for the formation of critical nuclei. The entire growth kinetics informed that the grown crystals were derived by the one dimensional diffusion controlled process. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
45.
An efficient method for the synthesis of substituted isoquinolinium salts from benzaldehydes, amines, and alkynes via ruthenium-catalyzed C-H bond activation and annulation in one pot is described. 相似文献
46.
K. Jeyadheepan P. Palanichamy V. Swaminathan M. Jayachandran C. Sanjeeviraja 《Applied Physics A: Materials Science & Processing》2010,98(4):919-925
Cadmium stannate (Cd2SnO4) thin films were prepared by the RF magnetron sputtering technique on glass substrates with substrate temperatures of room
temperature (RT), 100°C, 200°C and 300°C. Photoacoustic analyses were made to obtain the thermal diffusivity and the optical
bandgap values of the Cd2SnO4 thin films. The change in thermal diffusivity of the films with the substrate temperature was analyzed. The optical bandgap
values obtained from the photoacoustic spectroscopy were compared with the values obtained from the optical transmittance
spectra. X-ray photoelectron spectroscopic (XPS) studies confirm the formation of stoichiometric films. Surface morphological
studies by atomic force microscopy (AFM) revealed the crystalline nature of the films deposited at 100°C. 相似文献
47.
This paper presents numerical simulation of the physical phenomena in heat pipe. The vapour dynamics of working fluid is considered in the numerical analysis of the heat pipe. A two-phase analysis is carried out for the heat pipe. The compressible flow equations for vapour-phase interaction with water particle phase are solved by a finite volume technique. A three stage Runge-Kutta time-stepping method is employed to solve vapour dynamics. Damping term is added to stablize the numerical scheme. An example is worked out to study the two phase flow in the heat pipe. 相似文献
48.
S. P. Patil D. B. Kalgutkar N. Jayachandran V. K. P. Unny 《Journal of Radioanalytical and Nuclear Chemistry》2005,266(1):75-78
Summary An attractive and simple method has been developed for the preparation of ammonium [14C]thiocyanate from [14C]thiourea which eliminates the necessity of handling highly hazardous potassium [14C] cyanide. [14C]thiourea was isomerized to ammonium [14C]thiocyanate by heating the aqueous solution of thiourea (12%) in a sealed tube at 160 °C for 24 hours. The product formed was purified by silica-gel column chromatography. A radiochemical yield of 92.7% was obtained based on [14C]thiourea. The specific activity of the product obtained was 53.3 mCi/mmol (1.97 GBq/mmol) and the radiochemical purity was greater than 99%. This method has not been reported so far for the production of this labeled compound. 相似文献
49.
Reaction of 1,3-disubstituted isobenzofurans (IBFs) with selenium dioxide in tetrahydrofuran (THF) at room temperature led to the formation of 1,2-diaroyl/(heteroaroyl)benzenes in good to excellent yields. 相似文献
50.
Liquid-liquid extraction separation of iron(III) with 2-ethyl hexyl phosphonic acid mono 2-ethyl hexyl ester (PC-88A) in toluene has been studied. Quantitative extraction of iron(III) with 5 x 10(-3) M PC-88A in toluene is observed in the pH range 0.75-2.5. From the extracted complex species in the organic phase iron(III) was stripped with 1-4 M HNO(3), 1.5-4 M H(2)SO(4) and 1.5-4 M HCl, and later determined spectrophotometrically by thiocyanate method. Separation of iron(III) was carried out with some of the first transition metals in binary and multicomponent mixtures. This method was extended for the determination of iron in real samples. 相似文献