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51.
K. R. Krishna Iyer P. Neelakantan T. Radhakrishnan 《Journal of Polymer Science.Polymer Physics》1968,6(10):1747-1758
The Rayleigh-Gans theory of light scattering by a homogeneous cylinder has been applied to the case of scattering by a pad of fibers immersed in a liquid. The theory enables one to locate precisely the matching wavelength at which the mean refractive index of a sample of optically heterogeneous fibers coincides with that of an immersion medium. Thereby it offers a method of determining the mean refractive index. Besides, it facilitates a quantitative estimation of the variability of refractive index. The new technique has been used to study the birefringence of untreated cotton and ramie. The results are presented and discussed. 相似文献
52.
Utility of Zeo-Karb 226 and Dowex A-l for the separation of Tl and In at 5-ppm level from high-purity zinc and zinc-base alloys has been investigated. With Zeo-Karb 226 (NH(4)(+)), T1(+) is conveniently separated from these materials and also from many other cations, with l.0M ammonium nitrate as the eluent. It is subsequently determined with Rhodamine B. This separation principle is also applied to the analysis of Pb-Tl alloys. Both Tl and In (along with Fe) are preconcentrated on Zeo-Karb 226(H(+)) from a solution of the sample at pH 3.0. Suitable methods of subsequent determination of Tl and In are described. In the case of Dowex A-1(H(+)), Tl(+), In(3+), Fe(3+) and Cu(2+) are retained from a solution of the sample at pH 2.0. An o-phenanthroline solution at pH 2.0 elutes all but traces of Cu(2+). In(3+) along with Fe(3+) is eluted with l.0M hydrochloric acid. Finally, Tl is eluted with 2.0M hydrochloric acid containing sulphurous acid. 相似文献
53.
54.
The galleries of an Mg-Al layered double hydroxide have been functionalized by intercalation of carboxymethyl beta-cyclodextrin cavities. The anchored cavities form a random array of identical-sized hydrophobic nanopockets arranged in a bilayer fashion in the interlamellar space of the layered solid. Naphthalene molecules have been included within these cavities by partitioning from a polar solvent. The fluorescence from the included naphthalene shows an unusual behavior--the excimer to monomer emission intensity decreases with increasing concentration of included naphthalene. This is shown to be a consequence of the absence of translational mobility of the naphthalene--cyclodextrin adduct in the functionalized solid. Two types of included naphthalene have been identified: a preformed excimer-like species characterized by the absence of rise time in decay measurements and a monomeric species that is incapable of excimer formation due to the absence of suitably located included naphthalenes in its proximity. The concentration of each species and the enthalpy for excimer formation have been determined from the temperature variation of fluorescence intensities. 相似文献
55.
Jaya N. Iyer 《Compositio Mathematica》2003,136(3):317-321
In this paper, we show that the Chern classes c
k
of the de Rham bundle
defined on any good toroidal compactification
of the moduli space of Abelian varieties of dimension g are zero in the rational Chow ring of
, for g=4, 5 and k>0. 相似文献
56.
Jaya N. Iyer 《Transactions of the American Mathematical Society》2003,355(8):3209-3216
We show that ample line bundles on a -dimensional simple abelian variety , satisfying 2^g\cdot g!$">, give projective normal embeddings, for all .
57.
In this paper we derive a probabilistic representation of the deterministic three‐dimensional Navier‐Stokes equations based on stochastic Lagrangian paths. The particle trajectories obey SDEs driven by a uniform Wiener process; the inviscid Weber formula for the Euler equations of ideal fluids is used to recover the velocity field. This method admits a self‐contained proof of local existence for the nonlinear stochastic system and can be extended to formulate stochastic representations of related hydrodynamic‐type equations, including viscous Burgers equations and Lagrangian‐averaged Navier‐Stokes alpha models. © 2007 Wiley Periodicals, Inc. 相似文献
58.
Venkatesh Vasudevan Robert D. Cook Ronald K. Hanson Craig T. Bowman David M. Golden 《国际化学动力学杂志》2008,40(8):488-495
The reaction between methyl and hydroxyl radicals has been studied in reflected shock wave experiments using narrow‐linewidth OH laser absorption. OH radicals were generated by the rapid thermal decomposition of tert‐butyl hydroperoxide. Two different species were used as CH3 radical precursors, azomethane and methyl iodide. The overall rate coefficient of the CH3 + OH reaction was determined in the temperature range 1081–1426 K under conditions of chemical isolation. The experimental data are in good agreement with a recent theoretical study of the reaction. The decomposition of methanol to methyl and OH radicals was also investigated behind reflected shock waves. The current measurements are in good agreement with a recent experimental study and a master equation simulation. © 2008 Wiley Periodicals, Inc. 40: 488–495, 2008 相似文献
59.
S. Kapoor C. Gopinathan R. M. Iyer 《Journal of Radioanalytical and Nuclear Chemistry》1989,130(2):409-415
Trapped electron (e
T
–
) reactivity in methanol-isopropanol glasses irradiated at 77 K has been studied as a function of trap-depth, the variation in the trap depth being achieved by varying the methanol:isopropanol ratio. Benzyl chloride and carbon disulfide have been used as scavengers. In the case of the glasses containing benzyl chloride, the observed yield of the benzyl radical has been correlated with the trapping efficiency of the matrix. The data has been interpreted with the aim of assessing the relative importance of tunnelling in the scavenging of electrons in low temperature glassy matrices. 相似文献
60.
Vivekanandan Kannan Pradeep Narayanaswamy Deepak Gadamsetty Partha Hazra Anand Khedkar Harish Iyer 《Rapid communications in mass spectrometry : RCM》2009,23(7):1035-1042
Glycoforms of glargine expressed in Pichia pastoris were isolated by high‐performance liquid chromatography and analyzed by a series of chemical and mass spectrometric methods for the identification of various glycoforms, glycosylation position, nature and structure of glycans. Reduction and alkylation, peptide mapping techniques were used to decipher the amino acid site at which glycosylation had taken place. Chemical methods were coupled with mass spectrometry techniques such as electrospray ionization and matrix‐assisted laser desorption/ionization for identification of the glycosylation site. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献