Sensitivity analysis for shortest path problems and maximum capacity path problems in undirected graphs

This paper addresses sensitivity analysis questions concerning the shortest path problem and the maximum capacity path problem in an undirected network. For both problems, we determine the maximum and minimum weights that each edge can have so that a given path remains optimal. For both problems, we show how to determine these maximum and minimum values for all edges in O(m + K log K) time, where m is the number of edges in the network, and K is the number of edges on the given optimal path.     

Short range order and the development of long range order in Ni4Mo

The short-range ordered structure present in quenched Ni₄Mo and the initial development of the long-range-ordered structure have been studied using single crystal X-ray diffuse scattering techniques. Measurements of the diffuse X-ray intensities were made in a volume in reciprocal space for the f.c.c. alloy resulting in a quantitative determination of the three dimensional local-order parameters. The local-order parameters were used for a computer simulation of the atomic configuration.The local atomic arrangements for the quenched alloy consist of a strong preference for no molybdenum atom pairs as first neighbors. The atoms tend to satisfy the long-range-ordered structure of Ni₄Mo in which there are no Mo-Mo pairs as first neighbors, only one Mo atom as second neighbors and six or more as third neighbors. A rodlike morphology consisting of a strong preference for 200 and 400 Mo-Mo pairs exists on ordering for 5 min at 650°C. This result is similar to the rodlike morphology present in dilute Ni-W alloys and explains the [100] streaking of the short-range order peaks observed in the diffraction studies.     

Coupled-channels calculations of intermediate energy π−C inelastic scattering and charge exchange

Coupled-channels calculations have been carried out for pion inelastic scattering and charge exchange on 1p-shell nuclei at pion energies between 120 and 226 MeV. A momentum space technique is used, with the 1p-shell shell-model wavefunctions of Cohen and Kurath. Results are presented here for A=13. Channel-coupling effects are negligible in the strong 3/2^- and 5/2^- inelastic excitations of ¹³C, but enhance the analog charge-exchange cross sections by 7 to 20%.     

Metrics of static spheroidal charged dust distributions

Two sets of solutions for a static incoherent charge distribution with spheroidal symmetry are presented. In one set, the charge distribution can be bounded and the charge-to-mass-density ratio is unity everywhere in relativistic units. In the other, the distribution pervades the entire space and the ratio of charge to mass-density also varies at different points.U.G.C. Teacher-fellow, on leave from Physics Department, B.N. Mahavidyalaya, Itachuna, Hooghly, India.     

On the gate-controlled surface capacitance of MOS structures of Si having n-channel inversion layers

An attempt is made to work out a simple theory of gate-controlled MOS capacitance based on the triangular potential-well approximation. The predicted dependence of the capacitance on gate voltage is in excellent qualitative agreement with the recent experimental observation reported elsewhere.On leave of absence fromthe Dept. of Physics, University of Patna, Patna, India.     

Influence of a large magnetic field on electron diffusion in degenerate n-type specimens of InAs and InSb at very low temperatures

An expression is derived for the diffusivity-mobility ratio of the electrons in highly degenerate n-type specimens of InAs and InSb at very low temperatures in the presence of a large magnetic field. It is then shown that the diffusivity-mobility ratio and the diffusivity decrease continuously with increasing magnetic field. This is indirectly supported by showing agreement between the magnetic field dependence of the ratio and that of the linewidth of spontaneous emission from InSb junction lasers as reported in the literature.The authors are indebted to Professor J. N.Bhar for his keen interest in the work.     

Terpenoids—LVIII Base catalysed reactions with N-lithioethylenediamine

The use of lithioethylenediamine as a dehydrogenating and isomerizing reagent has been further extended and applied to new mono-, sesqui- and diterpenes. Structures of reaction products, including the phenol (XXVII), recently obtained as a degradation product of copaene, were decided on the basis of IR, UV and NMR spectral studies. Some of the transformations carried out with the help of this reagent do not appear possible with any other known reagent.     

Influence of band tails on the diffusivity-mobility ratio in highly degenerate semiconductors

The diffusivity-mobility ratio of the carriers in highly degenerate semiconductors in which the impurity states form band tails is shown to be directly determined by the characteristic energies of the tails at low temperatures.