• Volume 10, Issue 1

      January 1978,   pages  1-113

    • Photo and electroluminescence of ZnO : Er and ZnO : Ag, Er electroluminors

      S Bhushan M Saleem S Chandra

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      A number of ZnO : Er and ZnO : Ag, Er electroluminors have been prepared and their photo (PL) and electroluminescent (EL) properties investigated. While the addition of Ag slightly shifts the PL spectra towards longer wavelength side, the EL spectra not only shift but consist of some new transitions. In ZnO : Er electroluminors, additional transitions also exist at higher frequencies of excitations. Brightness waves for this system consist of two secondary peaks during each half cycle of exciting field. Temperature dependence shows two broad peaks. While voltage dependence of ZnO : Er satisfies the relationB=B0 exp(−b/V1/2), the relationB=B0V exp(−b/V1/2) is found to be suitable for ZnO : Ag, Er electroluminor. Possible mechanisms for these phenomena have been proposed.

    • Effect of the crystal potential on electronic polarizabilities of ions in alkaline earth chalcogenides

      S C Agrawal O P Sharma Jai Shanker

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      The electronic polarizabilities of ions in alkaline earth chalcogenides are estimated by taking account of the effect of the crystalline potential. The polarizabilities thus obtained are found to present a good agreement with experimental data. It has been shown that the polarizabilities and radii of alkaline earth and chalcogenide ions follow the polarizability-radius cube relation approximately well.

    • Thermodynamic perturbation theory for the (12-6-n) fluids

      K P Shukla

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      A perturbation method in which attractive forces are taken as perturbation of the repulsive (reference) forces is applied to calculate the thermodynamic properties of (12-6-n) fluids in terms of the properties of hard-sphere fluid. The numerical values of the thermodynamic properties (free energy per particle, compressibility and excess internal energy) for a range of temperature and density are given for (12-6-8) fluids. Further, two perturbation schemes are adopted to evaluate the total radial distribution function using the EXP version of the optimized cluster theory (OCT). The numerical results are reliable as reported at two states (T* = 1·036,ρ* = 0·65 andT* = 0·719ρ* = 0·85) for the (12-6-8) fluid and the Lennard-Jones (12-6) fluid as well.

    • Generation of gluons from quark confinement

      G Rajasekaran V Srinivasan

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      We study a model of quark confinement defined by the vanishing of colour currents. The model is shown to be equivalent to quantum chromodynamics and this equivalence is interpreted as due to the compositeness of the colour gluons. The Green’s functions of the theory are found to contain nontrivial structure only for colour singlet composites which can be identified with hadrons.

    • Independent particle model approach to nuclear mass formula and mass relationships

      Jitendra C Parikh

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      A nuclear mass formula is derived using a few extremely reasonable assumptions within an independent particle model with residual interactions. The parameters in the mass formula are determined by a least square fit to the experimental energies. The mass formula is further used to study Garvey-Kelson and Franzini-Radicati mass relationships.

    • Elastic scattering of electrons by argon atoms

      S P Khare Ashok Kumar

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      The partial wave method with a central potential has been applied to investigate the elastic scattering of electrons by the argon atoms in the intermediate energy range (100 eV − 1 keV). The central potential includes the effects of the static field, exchange and polarization. The results are in good accord with recent experimental data.

    • Extremum uncertainty product and sum states

      C L Mehta Sunil Kumar

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      We consider the states with extremum products and sums of the uncertainties in non-commuting observables. These are illustrated by two specific examples of harmonic oscillator and the angular momentum states. It shows that the coherent states of the harmonic oscillator are characterized by the minimum uncertainty sum 〈(Δq)2〉 + 〈(Δp)2〉. The extremum values of the sums and products of the uncertainties of the components of the angular momentum are also obtained.

    • Method for construction of operators in Fock space

      Alberto Chamorro

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      It is shown, by providing a general method for the construction that any Fock space linear operator defined on the dense linear manifold spanned by the particle number representation basis can be represented in terms of the annihilation and creation operators. The normal form of the representation is unique.

    • Deterministic model equations of motion for quantum mechanics and some new modes of quantum behaviour

      R K Varma

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      In this paper we propose a deterministic basis for quantum mechanics and give equations of motion (derivable from an action principle) which describe deterministic trajectories in an extended space that the quantum events are assumed to follow. By applying the laws of classical probability, namely the conservation of probability along the deterministic trajectories, we derive a probability description which is found to be a generalization of the Schrödinger description with built-in probability interpretation. The generalized description admits of an infinite number of wave functions following coupled set of Schrödinger-like equations while the total probability is given by the sum of the modulus squared of all these wave functions, one of which is identified as the Schrödinger function. If all the functions other than the Schrödinger wave function be neglected the Schrödinger description is retrieved. It is thus concluded that the classical probability not only embrances probability in quantum mechanics but allows other new modes for its propagation.

      We thus predict new modes of quantum behaviour and we discuss two situations and propose experiments where these modes could be looked for. Finally, our theory also provides an identification for the quantum of action, ħ.

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