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131.
132.
133.
An experimental configuration based on gated, double boundary GaAs/AlGaAs devices provides the first demonstration of dual distinct, tunable Hall resistances in the same sample over the weak- and strongmagnetic field limits, including the simultaneous observability of dual quantized Hall effects of dissimilar filling factors. These experiments suggest that the ordinary Hall resistance examined in experiment is essentially a topological resistance determined by connectivity, which need not reflect all “local” values of the off-diagonal resistivity, θ M ρ xy . 相似文献
134.
We consider the problems of finding the maximum number of vertex-disjoint triangles (VTP) and edge-disjoint triangles (ETP) in a simple graph. Both problems are NP-hard. The algorithm with the best approximation ratio known so far for these problems has ratio 3/2+?, a result that follows from a more general algorithm for set packing obtained by Hurkens and Schrijver [On the size of systems of sets every t of which have an SDR, with an application to the worst-case ratio of heuristics for packing problems, SIAM J. Discrete Math. 2(1) (1989) 68-72]. We present improvements on the approximation ratio for restricted cases of VTP and ETP that are known to be APX-hard: we give an approximation algorithm for VTP on graphs with maximum degree 4 with ratio slightly less than 1.2, and for ETP on graphs with maximum degree 5 with ratio 4/3. We also present an exact linear-time algorithm for VTP on the class of indifference graphs. 相似文献
135.
R.G. Mani 《Solid State Communications》2007,144(9):409-412
We illustrate some experimental features of the recently discovered radiation-induced zero-resistance states in the high-mobility GaAs/AlGaAs system, with a special emphasis on the interplay between the radiation-induced changes in the diagonal resistance and the Hall effect. We show that, quantum Hall effects, i.e., quantum Hall plateaus, disappear under photoexcitation, at the minima of the radiation-induced magnetoresistance oscillations. 相似文献
136.
A molecular force field for the study of the dynamics of graphite has been reported earlier (Mani and Ramani 1974). In the
present paper we present calculations of the single phonon density of states and the lattice specific heat. Most of the peaks
in the frequency distribution function have been identified and classified using symmetry-required critical points. The validity
of the force field used has also been discussed. 相似文献
137.
M. R. A. Pillai J. H. Gupte T. Jyotsna R. S. Mani 《Journal of Radioanalytical and Nuclear Chemistry》1987,116(1):193-202
Radioiodinated insulin and thyroid stimulating hormones were prepared using 1,3,4,6-tetrachloro-3, 6-diphenylglycouril (Iodogen). Conditions of iodination like concentration of iodogen, reaction time, etc., were optimized to get maximum yield. Stability studies of iodogen coated tubes were carried out over a period of time. The dependence of iodination yield on varying amounts of activity and protein concentration were investigated. Iodination yield over a range of pH was also studied. The radiolabelled hormones prepared by this method were used in radioimmunoassay and were compared with tracers prepared by the Chloramine-T method. 相似文献
138.
Ohne Zusammenfassung
Der erste Verfasser ist von einer Harkness Fellowship des Commonwealth Fund unterstützt worden, der zweite Verfasser von einem
Stipendium des Schweizerischen Nationalfonds 相似文献
139.
140.
P. Mani 《Israel Journal of Mathematics》1971,9(3):380-388
In the first part, the Euler-Gram formula for the angle sum of a convex polytope is extended to cellular decompositions of
arbitrary polyhedra. The second part contains an attempt to define Steiner points for unions of finitely many convex compact
sets, and states some of their properties.
Research supported by a fellowship of the Swiss National Foundation. 相似文献