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31.
The IR and Raman spectra are measured and analysed for sodium pyrophosphate decahydrate. The spectra are interpreted on the
basis of P2O
7
4−
ion and water vibrations. The observed results fit with the features predicted for the factor goup model. The appearance
of two sets of frequencies in the stretching and bending regions of water suggests the existence of two kinds of water molecules
in the crystal. This is confirmed by deuterium substitution. 相似文献
32.
M. R. Aswatha Narayana Rao 《Proceedings Mathematical Sciences》1940,12(4):354-356
33.
Dhevalapally B. Ramachary Vidadala V. Narayana Kinthada Ramakumar 《Tetrahedron letters》2008,49(17):2704-2709
A practical and novel ionic liquid promoted organocatalytic selective diazo-transfer process for the synthesis of highly substituted diazo-compounds in high yields is reported. The ionic liquid can be reused without affecting the reaction rates or yields over five runs. 相似文献
34.
35.
Grzegorz Dutkiewicz B. P. Siddaraju H. S. Yathirajan B. Narayana Maciej Kubicki 《Journal of chemical crystallography》2010,40(11):970-974
Abstract
The title compound, C22H28F3N3OS2+ × 2(C6H2N3O7 −) × (CH3)2SO—the picrate salt of the potent antipsychotic drug, fluphenazine—crystallizes in the triclinic P-1 space group with unit cell parameters a = 10.6333(12) ?, b = 11.9696(12) ?, c = 17.7036(15) ?, α = 103.265(9)°, β = 98.414(9)°, γ = 102.702(10)°. The ionic fragments: the fluphenazinium dictation, and two picrate anions, are joined by means of strong N–H···O and weak C–H···O hydrogen bonds into the chains of alternating cations and anions, expanding along [010] direction. Within the chain, the picrates interact by means of short π···π interactions: the mean distance between the planes is 3.366 ?; additional interaction of the same type between one of the picrates and the phenyl ring of the phenothiazine ring system additionally strengthen the pattern. The phenothiazine ring exists in a typical, “butterfly-like” conformation, with two terminal rings planar and the central ring in a slightly flattened boat form. This conformation results in the dihedral angle between the terminal rings of 41.76(5)°. The aliphatic chain which substitutes phenothiazine at N-position is not in an extended conformation, the torsion angles along this chain are 75.95(14)° and −163.96(10)°. The structure contains also the solvent—dimethylsulphoxide molecules, which are connected with the cation–anion structure by means of strong O–H···O hydrogen bonds. 相似文献36.
We report a new kind of experiment in which we take an array of nanoscale apertures that form a superfluid (4)He Josephson junction and apply quantum phase gradients directly along the array. We observe collective coherent behaviors from aperture elements, leading to quantum interference. Connections to superconducting and Bose-Einstein condensate Josephson junctions as well as phase coherence among the superfluid aperture array are discussed. 相似文献
37.
K.L.N. Deepak R. Kuladeep V. Praveen Kumar S. Venugopal Rao D. Narayana Rao 《Optics Communications》2011,284(12):3074-9305
We report microfabrication of structures in bulk and thin films of polystyrene (PS) using femtosecond (fs) laser pulses. For the first time to our knowledge, we report emission from the fs laser modified regions of bulk and thin films of PS when excited at 458, 488, and 514 nm. Moreover, we report the existence of peroxide type free radicals, for the first time, in fs laser irradiated bulk PS. We observed the suppression of Raman modes in case of structures fabricated at higher energies and the same effect was noticed in central portion of the structures fabricated. No appreciable broadening was observed in the case of structures fabricated at low energies. Possible applications resulting from such structures are discussed briefly. 相似文献
38.
S. Narayana Murthy 《Tetrahedron letters》2010,51(28):3649-237
Various 2-amino-4H-chromen-4-yl phosphonate derivatives were synthesized in good yields by condensation of salicylaldehyde, malononitrile or ethylcyanoacetate, and triethyl phosphite using β-cyclodextrin as a reusable catalyst under neutral conditions, in water. 相似文献
39.
G. Kavitha S. R. C. Vivek A. Govindaraj Chandrabhas Narayana 《Journal of Chemical Sciences》2003,115(5-6):689-694
The paper discusses the design of a low cost Raman spectrometer. Single-walled nanotubes (SWNT) have been studied to demonstrate
the reach of such a system. We observe both the radial-breathing mode (RBM) and the tangential mode from the SWNT. The tube
diameters of the SWNT used in these experiments have been determined using RBM to be predominantly 1.4 and 1.6 nm. These are
consistent with the TEM images taken of the same sample. The new method of producing SWNT using Ni-Y catalyst in electric-arc
discharge method produces nanotubes with very small dispersion in diameter and high yields. The chirality of the SWNT can
be deduced from their radial breathing modes, and it suggests that they are metallic in nature.
Dedicated to Professor C N R Rao on his 70th birthday 相似文献
40.
A. Lavagno A.M. Scarfone P. Narayana Swamy 《The European Physical Journal C - Particles and Fields》2006,47(1):253-261
On the basis of non-commutative q-calculus, we investigate a q-deformation of the classical Poisson bracket in order to formulate
a generalized q-deformed dynamics in the classical regime. The obtained q-deformed Poisson bracket appears invariant under
the action of the q-symplectic group of transformations. Within this framework we introduce the q-deformed Hamilton equations
and we derive the evolution equation for some simple q-deformed mechanical systems governed by a scalar potential dependent
only on the coordinate variable. It appears that the q-deformed Hamiltonian, which is the generator of the equation of motion,
is generally not conserved in time but, in correspondence, a new constant of motion is generated. Finally, by following the
standard canonical quantization rule, we compare the well-known q-deformed Heisenberg algebra with the algebra generated by
the q-deformed Poisson bracket.
PACS 02.45.Gh, 45.20.-d, 03.65.-w, 02.20.Uw 相似文献