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61.
In this article, we present a comparative study of the Raman spectra of alkali halides in relation to the lattice dynamics ofBorn andRaman. It is shown that the experimentally observed limit of the second-order spectra in almost all the cases can be explained well by the Lyddane-Sachs-Teller relation. It is also seen, while, an explanation of the second-order Raman spectrum of a crystal of diamond or zinc blende structure requires the frequencies from the critical points,W, Γ, X andL inBorn's analysis, the frequencies fromΓ, X andL alone are sufficient and necessary for an interpretation of the same onRaman's model. Some similarities in the determination of the long wave properties of crystals like elastic constants and limiting frequencies of the lattice vibrations in the symmetry directions in both the models are pointed out. 相似文献
62.
B. S. Maruthiprasad M. N. Sastri S. Rajagopal K. Seshan K. R. Krishnamurthy T. S. R. Prasada Rao 《Journal of Chemical Sciences》1988,100(6):459-462
The preparation of a novel nickel trihydroxy isocyanate, along with its distinguishing physicochemical characteristics has
been reported for the first time. 相似文献
63.
64.
V. G. Krishnamurthy 《Zeitschrift für Physik A Hadrons and Nuclei》1958,152(2):242-248
The ultraviolet bands of mercury bromide have been excited in uncondensed discharge and photographed with a quartz Littrow spectrograph. The class II system, lying betweenλ 2900 å to 2700 å, suggested byWieland as due to the triatomic molecule, has been studied in detail and ascribed to the diatomic molecule. The bands in the regionλ 2900 å to 2770å have been analysed into two systems which may form the two components of a2 II ?2 σ electronic transition with a2 II interval equal to 969·4 cm?1. Another system most probably due to2 σ?2 σ has been observed in the regionλ 2770 to 2720. 相似文献
65.
K.R. Sridharan J. Ramakrishna K. Ramachandran S.S. Krishnamurthy 《Journal of Molecular Structure》1980
The frequencies and variable-temperature behaviour of 35Cl nuclear quadrupole resonance in three aminocyclophosphazene derivatives are reported. The observed frequencies and multiplicity are correlated with the disposition of the substituents and the crystal structure. The temperature-dependence data are discussed in the framework of Bayer-Kushida-Brown equations and low-lying torsional (librational) frequencies and their average temperature coefficients are estimated. Brown's parabolic equation provides a good fit to the experimental data. Variable-temperature proton FT-NMR measurements (at 270 MHz) have also been carried out. The results are consistent with the NQR data and indicate the presence of two-site chemical exchange of the -NH protons and hydrogen bonding. 相似文献
66.
67.
68.
69.
Ghosh J. Varma A. Krishnamurthy N. 《Very Large Scale Integration (VLSI) Systems, IEEE Transactions on》1994,2(1):54-67
In a large nonblocking crossbar switch, the controller often becomes a bottleneck in terms of both performance and reliability. We present a number of schemes for distributing the setup function among multiple controllers, thus improving both the performance and the reliability of the switch. The controllers are symmetric and operate in parallel. We present four distributed control schemes that provide a range of tradeoffs in controller complexity, speed, and hardware overhead for nonblocking operation. We derive a lower bound of N(1-1/K) for the number of buses required for nonblocking operation of a crossbar switch with N ports and K controllers under certain constraints. We then describe a scheme that actually achieves this lower bound. Results from simulation indicate that the hardware overhead in terms of the extra buses needed is small for all the schemes if a small probability of blocking is acceptable 相似文献
70.
Collings I.B. Krishnamurthy V. Moore J.B. 《Signal Processing, IEEE Transactions on》1994,42(12):3535-3539
An on-line state and parameter identification scheme for hidden Markov models (HMMs) with states in a finite-discrete set is developed using recursive prediction error (RPE) techniques. The parameters of interest are the transition probabilities and discrete state values of a Markov chain. The noise density associated with the observations can also be estimated. Implementation aspects of the proposed algorithms are discussed, and simulation studies are presented to show that the algorithms converge for a wide variety of initializations. In addition, an improved version of an earlier proposed scheme (the Recursive Kullback-Leibler (RKL) algorithm) is presented with a parameterization that ensures positivity of transition probability estimates 相似文献