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611.
612.
Ring-scission polymerizations of 6-methyl and 6,7-methylenedioxybenz-3,1-oxazin-2,4-dione have been studied in the presence of catalysts such as aq HCl, the corresponding anthranilamide, N-methylaniline, o-chloroaniline and acid amides under various conditions. These substances underwent ring-scission polymerization affording polyanthranilides in the presence of the first four catalysts under appropriate experimental conditions. The samples were insoluble in all organic solvents including formic acid. They were soluble in sulphuric acid with degradation. They were characterized by i.r. and thermogravimetric analysis. 相似文献
613.
Georgios N. Charos Paulette Clancy Keith E. Gubbins Chandrashekhar D. Naik 《Fluid Phase Equilibria》1985,23(1):59-78
Interactive computer graphic techniques have been developed for the display of binary mixture phase diagrams. The diagrams are defined in temperature-pressure-composition space, and are portrayed as wireframe objects with depth perception in order to provide a three-dimensional effect. The displays used were vectro refresh workstations whose transformation hardware allows real-time rotation, rescaling, and translation of the diagrams, while software allows the extraction of constant property Px, Tx, PT and x - y plots. The equilibrium surfaces and the critical lines were calculated using the Redlich-Kwong equation of state and its Soave modification. 相似文献
614.
A recent proposal [1] correlating the Cotton effects and dione chirality of various cyclic α-diketones according to a skewed glyoxal model is held to require revision in the light of overriding evidence from molecular models and the effects expected from substituent chirality contributions. 相似文献
615.
Triethyl oxonium fluoroborate either preformed or preparedin situ by the reaction of boron trifluoride etherate with epichlorohydrin does not initiate the homo or copolymerization of vinyl
monomers. Small conversions to copolymers by use of these initiators with low methyl methacrylate incorporation is ascribed
to conventional vinyl copolymerizations, initiated by free boron trifluoride and/or protonic impurities in the system. 相似文献
616.
617.
618.
R.A. Ganeev A.I. Ryasnyanskiy U. Chakravarty P.A. Naik H. Srivastava M.K. Tiwari P.D. Gupta 《Applied physics. B, Lasers and optics》2007,86(2):337-341
A study of indium nanoparticles prepared by two laser ablation techniques is reported. The suspensions of indium nanoparticles
were prepared using the laser ablation of bulk indium in liquids. The prepared suspensions of indium nanoparticles were analyzed
by the X-ray fluorescence spectroscopy and absorption spectroscopy. The position of the surface plasmon resonance of In-containing
suspensions (350 nm) was consistent with the estimations taking into account the average size of In nanoparticles (43 nm)
measured using the X-ray fluorescence spectroscopy. The nonlinear optical parameters of indium nanoparticles-containing liquids
were studied by the z-scan technique using a picosecond Nd:YAG laser. We compare the laser ablation in liquids with the laser
ablation of indium in vacuum at the tight and weak focusing conditions of a Ti:sapphire laser and analyze the 60 nm indium
nanoparticles synthesized in the latter case.
PACS 42.65.An; 42.65.Hw; 42.65.Jx; 61.46.Df; 78.67.Bf 相似文献
619.
R. A. Ganeev P. A. Naik H. Singhal U. Chakravarty V. Arora J. A. Chakera R. A. Khan M. Raghuramaiah S. R. Kumbhare R. P. Kushwaha P. D. Gupta 《Optics and Spectroscopy》2007,103(5):831-838
The results of investigation of the higher harmonics (from the 21st to the 61st order) of radiation of a femtosecond laser (793 nm, 48 fs) that are generated in silver plasma are presented. The changes in the shape and spectra of harmonics for different chirps of the laser radiation are studied. It is found that the wavelengths of harmonics generated in the region of the plateaulike distribution of the converted radiation intensity can be tuned. It is shown that the conditions of phase matching between harmonics and laser radiation are different for different modulations of the femtosecond pulse spectrum. The tuning range of the spectrum of the converted radiation in the region of lower harmonics, which lie in the beginning region of the plateau, is shown to amount to 0.8 nm. 相似文献
620.
G. Ramesh J. Prashanth J. Laxman Naik B. Venkatram Reddy 《Journal of Structural Chemistry》2018,59(5):1022-1031
In this study, FT-IR and FT-Raman spectra of 3-methyl picolinic acid (MPA) are recorded in the ranges 4000–450 cm–1 and 4000–50 cm–1, respectively. The optimized geometry is obtained by scaled quantum mechanical calculations using density functional theory employing the B3LYP functional with the 6–311++G(d,p) basis set. Vibrational assignments are suggested for all the fundamental vibrations unambiguously, using the potential energy distribution obtained in the computations. The rms error between the observed and calculated frequencies is found to be 8.48 cm–1. The dipole moment, polarizability, and hyperpolarizability values are computed to study the NLO behavior of the molecule. The NBO analysis is made to study the stability of the molecule arising from hyperconjugative interactions and charge delocalization. 相似文献