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951.
952.
In the present paper an attempt has been made to draw theoretically a correlation between the well-known Paschen curve and
the high-frequency breakdown characteristic of a gas device by interpreting electron mean free path in terms of the frequency
of the applied field. The analytical high-frequency breakdown characteristic, so obtained, agree fairly well with the experimental
results. 相似文献
953.
954.
955.
H. C. Meyer G. A. Tanton S. S. Mitra J. D. Stettler 《Applied Physics A: Materials Science & Processing》1977,13(3):307-309
The Faraday rotation associated with the Zeeman effect in gases is used to rotate the plane or polarization of plane polarized
light with low loss of intensity. Advantage is taken of the rapid decrease of absorption relative to Faraday rotation between
the split Zeeman components. Calculations of this Faraday rotation are applied to obtain design parameters for an isolator
for 5.26 μm which show a significant improvement over conventional designs. 相似文献
956.
Summary We study the thermoelectric power of the electrons under magnetic quantization in III–V, II–VI, PbTe/PbSnTe and strained layer
superlattices with graded interfaces and compare the same with the corresponding bulk specimens of the constituent materials
by formulating the respective expressions incorporating the broadening. It is found, by taking GaAs/Ga1−x
Al
x
As, CdS/CdTe, PbTe/PbSnTe and InAs/GaSb superlattices with graded interfaces as examples, that the thermoelectric power exhibits
oscillatory dependence with the inverse quantizing magnetic field due to Shubnikov-de Hass effect and increases with decreasing
electron concentration in an oscillatory manner in all the aforementioned cases. The thermopower in graded superlattices is
greater than that of constituent bulk materials together with the fact that the oscillations in superlattices show up much
more significantly as compared to the respective constituent materials. In addition, the well-known expressions for bulk specimens
of wide-gap semiconductors have also been obtained as special cases from our generalized expressions under certain limiting
conditions. 相似文献
957.
Nalâv Gülpinar Gautam Mitra István Maros 《Computational Optimization and Applications》2002,21(1):71-93
In this paper, we investigate how an embedded pure network structure arising in many linear programming (LP) problems can be exploited to create improved sparse simplex solution algorithms. The original coefficient matrix is partitioned into network and non-network parts. For this partitioning, a decomposition technique can be applied. The embedded network flow problem can be solved to optimality using a fast network flow algorithm. We investigate two alternative decompositions namely, Lagrangean and Benders. In the Lagrangean approach, the optimal solution of a network flow problem and in Benders the combined solution of the master and the subproblem are used to compute good (near optimal and near feasible) solutions for a given LP problem. In both cases, we terminate the decomposition algorithms after a preset number of passes and active variables identified by this procedure are then used to create an advanced basis for the original LP problem. We present comparisons with unit basis and a well established crash procedure. We find that the computational results of applying these techniques to a selection of Netlib models are promising enough to encourage further research in this area. 相似文献
958.
Recent experimental data on single hadron production by two-photon beams inpetra andpep have provided a unique opportunity for testing specific models of confinement through a study of one of their cleanest predictionsviz the γγ →H amplitudes. Motivated by this new facility, aqcd-oriented Bethe-Salpeter model of harmonic confinement, which has already been found to describe rather well several classes
of hadronic data (from mass spectra to electromagnetic and pionic couplings), is now employed for a detailed comparison of
its predictions onP → γγ andT → γγ couplings with the data. The agreement is quite good for all cases except one (η → γγ).
This paper is offered as a “Festschrift” in honour of Dr Raja Ramanna on the occasion of his sixtieth birthday. The subject
is theoretical in content but seeks to exploit an entirely new window opened by the latest experimental technology (on two-photon
physics). As such it is appropriately dedicated to one of the main architects of nuclear science in India. 相似文献
959.
960.
Aurpon W. Mitra Marvin M. HansenMichael E. Laurila Stanley P. KolisJoseph R. Martinelli 《Tetrahedron letters》2013
α-Aminoamides are shown to be useful as ligands in Goldberg amidations. A number of α-aminoamides are examined and the importance of substitution on the α-aminoamides is explored. Acetamide is focused on as the nucleophilic coupling partner due to its low cost, stability and convenience as a protecting group. The initial substrate scope for these catalysts is explored and includes electronically activated and deactivated aryl bromides, however o-substituted aryl bromides are problematic. 相似文献