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排序方式: 共有1627条查询结果,搜索用时 15 毫秒
991.
Ravi P. Agarwal Smail Djebali Toufik Moussaoui Octavian G. Mustafa 《Journal of Computational and Applied Mathematics》2007
The aim of the present paper is twofold. Firstly, the paper surveys the literature concerning a specific topic in asymptotic integration theory of ordinary differential equations: the class of second order equations with Bihari-like nonlinearity. Secondly, some general existence results are established with regard to a condition that has been found recently to be of significant use in the theory of elliptic partial differential equations. 相似文献
992.
Ravi Pandiselvam Rathnakumar Kaavya Sergio I. Martinez Monteagudo V. Divya Surangna Jain Anandu Chandra Khanashyam Anjineyulu Kothakota V. Arun Prasath S. V. Ramesh N. U. Sruthi Manoj Kumar M. R. Manikantan Chinnaraja Ashok Kumar Amin Mousavi Khaneghah Daniel Cozzolino 《Molecules (Basel, Switzerland)》2022,27(10)
993.
Spinel oxide Cr0.5 Li0.5 Fe2O4 has been irradiated at Nuclear Science Centre, New Delhi, by 50 MeV lithium ions of fluence 5*1013 ions/cm2 and irradiation effect on hyperfine interactions has been investigated by Mossbauer spectroscopy. The Mossbauer spectrum
of irradiated sample shows no paramagnetic doublet contribution and the hyperfine fields corresponding to the Fe3+ in the octahedral (B) and the tetrahedral (A) sites are very well separated. That is the observed superimposed A and B sites
in unirradiated sample are split into separate lines after Li irradiation. Further an increase of the intensity of the lines
(2)–(5) with respect to (1)–(6) signals an orientation of the hyperfine magnetic field towards a direction perpendicular to
the ion path due to the irradiation induced strain by the latent tracks. The computer simulation of Mossbauer spectra indicated
that the irradiated Fe3+-site occupancy of the A-site hyperfine field increased from 43% to 55% whereas the B-site hyperfine field decreased from
57% to 45% compared to unirradiated sample. 相似文献
994.
Pandey Ravi Kamal Prakash Ranjana Prakash Hari 《International Journal of Theoretical Physics》2019,58(10):3342-3351
Controlled quantum teleportation of superposed coherent states using GHZ entangled 3-mode coherent states is studied. Proposed scheme can be implemented experimentally using linear optical components such as a symmetric lossless beam splitter, two phase-shifters and two photon counters. Fidelity is found close to unity for appreciable mean number of photons in coherent states and is 0.99 for mean photon number equal to two.
相似文献995.
M K Malik V D Nair R V Raghavan P Chaddah P K Mishra G Ravi Kumar B A Dasannacharya 《Pramana》1987,29(3):L321-L326
The successful extrusion of short lengths of brittle wires of YBa2Cu3O
y
that are superconducting above 77 K is reported. Detailed critical current measurements are presented on wires having undergone
different physical treatments. The highest critical current obtained from V-I data is ⋍ 90 A/cm2, but this particular wire shows clear evidence of flux-pinning forces corresponding to ⋍ 130 A/cm2. 相似文献
996.
We have measured the transport critical current densityJ
cof sintered YBa2Cu3O7, in various applied fields up to 185 Oe at 77 K. We find a sharp decay ofJ
cwith magnetic field. We show that this sharp decay is consistent with the low field hysteresis results of Groveret al. We argue that the observed field dependence is not caused by intragranular weak links. 相似文献
997.
Ra. Shanmugavadivu G. Ravi A. Nixon Azariah 《Journal of Physics and Chemistry of Solids》2006,67(8):1858-1861
A new nonlinear optical material glycine potassium sulphate (GPS) has been synthesized and optical quality crystals were grown from aqueous solution. This material has positive temperature coefficient revealed from the solubility studies. The grown crystals were characterized by employing several techniques such as single crystal and powder X-ray diffraction, thermo gravimetric analysis, FTIR and UV-vis-NIR spectra. The etching studies have been done on the (1 0 0) plane of the grown crystal. Preliminary measurements to find second harmonic generation efficiency of GPS has been carried out. 相似文献
998.
The control of enantiomeric purity and determination of individual enantiomeric drug molecules remains the subject of importance for clinical, analytical, and regulatory purposes and to facilitate an accurate evaluation of the risks posed by them to human health. A large number of pharmaceuticals are marketed and administered as racemates. Etodolac is among such nonsteroidal anti‐inflammatory drugs. Overall literature reports on its enantioseparation are scanty. Liquid chromatography (LC) methods of enantioseparation of (±)‐etodolac, including certain unconventional ones, are well covered and discussed in this paper. Methods of direct approach without using chiral columns or chiral thin‐layer chromatography plate and of indirect approach using certain chiral derivatizing agents such as (S)‐naproxen and (S)‐levofloxacin are described. Most interesting aspects include establishment of structure and molecular asymmetry of chemically different types of diastereomeric derivatives using liquid chromatography with mass spectrometry (LC–MS), 1H NMR spectroscopy and by drawing conformations in three dimensional views by using certain software. The methods provide chirality recognition even in the absence of pure enantiomers. Besides, recovery of pure enantiomers by detagging or via solubility difference of chiral inducing reagent and the analyte, without racemization at any stage, has been achieved. The limits of detection and quantification are much lower than the industry benchmarks. 相似文献
999.
Charanya Ravi 《Journal of Pure and Applied Algebra》2018,222(10):3248-3254
We prove a Grothendieck–Lefschetz theorem for equivariant Picard groups of non-singular varieties with finite group actions. 相似文献
1000.
A. Padmanabham V. Ravi Kumar T. Satyanarayana N. Veeraiah 《Journal of Physics and Chemistry of Solids》2009,70(3-4):669-679
PbO–Sb2O3–As2O3 glasses mixed with different concentrations of MoO3 (ranging from 0 to 1.0 mol%) were crystallized. The samples were characterized by X-ray diffraction, scanning electron microscopy and differential thermal analysis techniques. The X-ray diffraction and the scanning electron microscopic studies have revealed the presence of Pb5Sb2O8, PbSb2O6, SbAsO4, Sb2MoO6, Sb4Mo10O31, As4Mo3O15, Pb5Sb4O11 crystalline phases in these samples. The differential thermal analysis indicated that the surface crystallization prevails over the bulk crystallization as the concentration of the crystallizing agent is increased. The infrared (IR) spectral studies exhibit bands due to MoO4 structural units in addition to the conventional bands due to various antimonate and arsenate structural groups. The studies on PbO–Sb2O3–As2O3: MoO3 glass-ceramics with respect to various physical properties viz., dielectric properties over a range of frequency and temperature, optical absorption, electron spin resonance (ESR) and magnetic susceptibility at room temperature have also been reported. The optical absorption, ESR and magnetic susceptibility studies indicated that the molybdenum ions exist in Mo5+ state in addition to Mo6+ state in these samples. The redox ratio found to increase as the concentration of the MoO3 is increased. The variations observed in all these properties with the concentration of the crystallizing agent have been analyzed in the light of different oxidation states and environment of molybdenum ions in the glass ceramic network. 相似文献