Resolution beyond natural linewidth via flourescence in modulated beams

A new method is proposed for obtaining spectral resolution beyond the natural linewidth using excitation by a laser beam whose intensity is weakly modulated in time at a low frequency ν. Th modulated fluorescence at 2ν, is shown to posses subnatural linewidth. The resolution of two lines lying within the natural linewidth of each other is explicitly considered.     

A simple method for calculating thermal expansion of crystals

Summary A simple method based on the classical statistical mechanics is suggested for the calculation of thermal expansion of crystals. The adequacy of the procedure is tested for alkali halide crystals in conjunction with the interatomic potential of the modified Born-Mayer Type.     

Evaluation of the thermodynamic parameters for association process of hydrogen bond complexes from the dielectric relaxation measurements.

A relation between the free energy for dipole relaxation process and that for the association process has been proposed. Using this relation, an equation has been defined for evaluating the association equilibrium constant from the dielectric relaxation measurements. These equations have been applied to study the association of dimethyl sulphoxide and p-tolyl sulphoxide with proton donors (phenol and O-cresol) in an inert solvent carbon-tetra-chloride in the temperature range 298–322K. The calculation of the association equilibrium constant and hence the thermodynamic parameters have shown the wide scope, the proposed relations can be put to in the study of the association process of hydrogen bond complexes.     

Electron and plasma stream reflection at a nonadiabatic mirror

Experimental investigations of the phenomena occurring when low density electron and plasma beams are injected into a nonadiabatic magnetic mirror are presented. Effects of nonadiabaticity and mirror ratio on the reflectivity of the magnetic mirror are measured. Transition of the mirror from adiabatic to strongly nonadiabatic results in setting up of a potential barrier which enhances the reflectivity.     

Transfer of charge in liquid alloys

Hard sphere diameters of liquid alkali metal alloys (Na-Cs and K-Rb) are calculated at 373 K ensuring the minimum Helmholtz free energy of the system. These diameters are then used to fix the packing density of the alloy. On alloying, the hard sphere diameters of Na in Na-Cs and K in K-Rb alloys expand whereas those of Cs and Rb contract.     

Interpolation by almost quartic splines

In this paper we define a new class of quartic splines of classC ² and solve the problem of (0, 2) interpolation by the elements of this class. We also study the possibility of the solution of the problems of (0, 1) and (1, 2) interpolations by the elements of the same class. Error estimates are obtained in each case.