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排序方式: 共有93条查询结果,搜索用时 15 毫秒
21.
Ezhil Raj AM Selvan G Ravidhas C Jayachandran M Sanjeeviraja C 《Journal of colloid and interface science》2008,328(2):396-401
MgIn(2)O(4), which has an inverse spinel structure, has been adopted as the transparent material in optoelectronic device fabrication due to its high optical transparency and electrical conductivity. Such a technologically important material was prepared by the spray pyrolysis technique. Precursors prepared for the cationic ratio Mg/In=0.5 were thermally sprayed onto glass substrates at 400 and 450 degrees C. We report herein the preparation and characterization of the films by X-ray diffraction (XRD), energy-dispersive absorption X-ray spectroscopy (EDAX), and atomic force microscopy (AFM). The XRD results showed the single phase formation of the material that revealed the presence of Mg(2+) and In(3+) in the inverse spinel-related structure. The FTIR and EDAX results further confirmed that the nanocrystalline films were mainly composed of magnesium, indium, and oxygen, in agreement with XRD analysis. We surmised from the AFM micrographs that the atoms have enough diffusion activation energy to occupy the correct site in the crystal lattice. For the 423-nm-thick magnesium indium oxide films grown at 400 degrees C, the electrical conductivity was 5.63x10(-6) Scm(-1) and the average optical transmittance was 63% in the visible range (400-700 nm). Similar MgIn(2)O(4) films deposited at 450 degrees C have a conductivity value of 1.5x10(-5) Scm(-1) and an average transmittance of 75%. Hall coefficient observations showed n-type electrical conductivity and high electron carrier concentration of 2.7x10(19) cm(-3). 相似文献
22.
Direct Synthesis of Protoberberine Alkaloids by Rh‐Catalyzed C−H Bond Activation as the Key Step
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Dr. Jayachandran Jayakumar Prof. Dr. Chien‐Hong Cheng 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(5):1800-1804
A one‐pot reaction of substituted benzaldehydes with alkyne–amines by a Rh‐catalyzed C?H activation and annulation to afford various natural and unnatural protoberberine alkaloids is reported. This reaction provides a convenient route for the generation of a compound library of protoberberine salts, which recently have attracted great attention because of their diverse biological activities. In addition, pyridinium salt derivatives can also be formed in good yields from α,β‐unsaturated aldehydes and amino–alkynes. This reaction proceeds with excellent regioselectivity and good functional group compatibility under mild reaction conditions by using O2 as the oxidant. 相似文献
23.
A numerically fast algorithm has been developed to solve the viscous two-phase flow in an axisymmetric rocket nozzle. A Eulerian–Eulerian approach is employed in the computation to couple the gas–particle flow. Turbulence closure is achieved using a Baldwin–Lomax model. The numerical procedure employs a multistage time-stepping Runge–Kutta scheme in conjunction with a finite volume method and is made computationally fast for the axisymmetric nozzle. The present numerical scheme is applied to compute the flow field inside JPL and AGARD nozzles. © 1998 John Wiley & Sons, Ltd. 相似文献
24.
Luttmann E Ensign DL Vaidyanathan V Houston M Rimon N Øland J Jayachandran G Friedrichs M Pande VS 《Journal of computational chemistry》2009,30(2):268-274
Implementation of molecular dynamics (MD) calculations on novel architectures will vastly increase its power to calculate the physical properties of complex systems. Herein, we detail algorithmic advances developed to accelerate MD simulations on the Cell processor, a commodity processor found in PlayStation 3 (PS3). In particular, we discuss issues regarding memory access versus computation and the types of calculations which are best suited for streaming processors such as the Cell, focusing on implicit solvation models. We conclude with a comparison of improved performance on the PS3's Cell processor over more traditional processors. 相似文献
25.
We present a technique for biomolecular free energy calculations that exploits highly parallelized sampling to significantly reduce the time to results. The technique combines free energies for multiple, nonoverlapping configurational macrostates and is naturally suited to distributed computing. We describe a methodology that uses this technique with docking, molecular dynamics, and free energy perturbation to compute absolute free energies of binding quickly compared to previous methods. The method does not require a priori knowledge of the binding pose as long as the docking technique used can generate reasonable binding modes. We demonstrate the method on the protein FKBP12 and eight of its inhibitors. 相似文献
26.
K. Ashok B. Subramanian P. Kuppusami M. Jayachandran 《Crystal Research and Technology》2009,44(5):511-516
Thin zirconium nitride (ZrN) films were prepared by using reactive direct current (DC) magnetron sputtering onto D9 steel substrates. XRD technique was employed to study the coatings, observing variations of crystallite size, crystallite texture and lattice constant, as a function of substrate temperature. Chemical states of the ZrN thin films were determined by X‐ray photoelectron microscopy (XPS). AFM picture showed the presence of spherical shaped grains on the top of homogeneous granular surface. The hardness and elastic modulus values were measured by nanoindendation and their values are 18.5 and 343 GPa respectively. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
27.
28.
Spectroscopically pure bismuth is evaporated onto glass substrates at different substrate temperature using a Hind Hivac coating
plant. The electrical conductivity of bismuth thin films, prepared at different substrate temperatures is measured and thermal
activation energy is evaluated. From the recorded optical absorption spectrum in the ultraviolet and visible regions optical
band gapE
g is determined. X-ray diffractograms are recorded and lattice parameters are determined. 相似文献
29.
K. P. Asokan J. Sebastian N. Jayachandran V. K. P. Unny 《Journal of Radioanalytical and Nuclear Chemistry》2005,262(3):767-769
Simple and easy to operate experimental assemblies were for the first time designed for the successful preparation of potassium 32P-phosphonate from 32P-orthophosphate. Phosphate was first converted to phosphoryl chloride by reacting with phosphorus pentachloride. Then the phosphoryl chloride formed was reduced to phosphorus trichloride by heating with charcoal at 650 °C. The latter was absorbed in aqueous potassium hydroxide to obtain potassium 32P-phosphonate at a yield of about 75%. The chemical purity of 32P-phosphonate was assayed using ion-chromatography and the radiochemical purity was also determined.The authors thank Shri. J. K. Ghosh, Chief Executive, BRIT and Dr. N. Sivaprasad, General Manager, RPh & ILCJ, BRIT for their support and encouragement throughout this work. 相似文献
30.
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