Density and flux analysis for the collinear H + H2, reaction

Quantal wavefunction, density and flux maps have been computed for the hydrogen exchange reaction. We find that the threshold for appearance of quantal     

Evaluation of functional integrals around a continuous set of important field configurations

For euclidean functional integrals, the relevance of configurations beyond the set of classical solutions is investigated. We propose an equation to select the important configurations and derive general expressions for their contribution to the integral. Employing a pseudoparticle picture, we perform a dilute-gas approximation and estimate finite-density corrections through a virial expansion. The methods are exemplified for the anharmonic oscillator and the double well potential.     

La selectivite de l'attaque au brome dans le cadre du dosage de l'oxygene dans l'aluminium: Selectivity of the bromine—methanol dissolution in the determination of oxygen in aluminium

(Selectivity of the bromine—methanol dissolution in the determination of oxygen in aluminium.) The chemical determination of oxygen in aluminium by the classical bromine—methanol method is compared with the 14-MeV neutron activation technique. It is shown that the bromine dissolution method is affected by compounds such as AlN or MgAl₂O₄. A mode of operation which limits the resulting error is proposed.     

Bonding criteria for diatomic molecular orbitals and inter-relations among them

Bonding criteria for molecular orbitals in diatomic molecules are discussed. An orbital force criterion is shown to have several conceptual and practical advantages, providing a basis for the investigation of inter-relations among many of the commonly employed criteria.It is found that interconsistency among those criteria is guaranteed, within the framework of Koopmans' Theorem, if the orbital energies are monotonic in the range (R _e, ).The application of the orbital force criterion to the second row homonuclear diatomics exhibits reasonable chemical trends concerning the valence-shell orbitals, as well as indications of a slightly antibonding nature of the inner orbitals.Based on a section of a thesis to be submitted by Y.T. to the Senate of the Technion-Israel Institute of Technology, in partial fulfilment of the requirements for the D.Sc. degree     

Sum rules from boundary dispersion relations

Sum rules for inelastic reactions are derived from boundary dispersion relations. If sufficient data or a model is available for the amplitude in the direct channel, then these sum rules provide a means of studying the dynamics in the cross channel. The convergence of these sum rules is investigated, assuming they can be saturated with narrow-width resonances, and rough estimates of the coupling constants of cross-channel exchanges for the photoproduction of pseudoscalar mesons are obtained.     

Intensity measurements,self-broadening coefficients,and rotational intensity distribution for lines of the oxygen B band at 6880 Å

Quantitative measurements of intensities and half-widths were made for individual rotational lines of the atmospheric oxygen B band. The total band intensity, as derived from the line intensity measurements, is 40·8±0·6 cm^?1km^?1atm^?1 STP. As had been previously found in this laboratory for the oxygen A band, the relative line intensities conform closely to the rotational distribution calculated by either Schlapp or by Watson. The line half-widths at half-intensity were determined for oxygen self-broadening for the ${}^{\mathrm{P}}\text{Q}$ and ${}^{\mathrm{P}}\text{P}$ branch lines and for a few ${}^{\mathrm{R}}\text{Q}$ and ${}^{\mathrm{R}}\text{R}$ branch lines near the band origin, and were found to vary from 0·064 cm^?1atm^?1 at J′ = 1 to 0·042 cm^?1atm^?1 at J′ = 25.     

r-entropy,equipartition, and Ornstein’s isomorphism theorem inR n

A new approach is given to the entropy of a probability-preserving group action (in the context ofZ and ofR _n ), by defining an approximate “r-entropy”, 0<r<1, and lettingr → 0. If the usual entropy may be described as the growth rate of the number of essential names, then ther-entropy is the growth rate of the number of essential “groups of names” of width≦r, in an appropriate sense. The approach is especially useful for actions of continuous groups. We apply these techniques to state and prove a “second order” equipartition theorem forZ _m ×R _n and to give a “natural” proof of Ornstein’s isomorphism theorem for Bernoulli actions ofZ _m ×R _n , as well as a characterization of such actions which seems to be the appropriate generalization of “finitely determined”.     

Open quasi-free systems

We compute the time evolution of an infinitely extended, open, quasi-free system in the weak coupling limit followed by the thermodynamic limit, and we derive the Onsager relations and the properties of entropy production.On leave of absence from Istituto di Fisica dell'Università, Milan, Italy     

On the occupation of interstitial sites by hydrogen atoms in intermetallic hydrides: A quantitative model

A simple model to predict the relative occupation numbers of various interstitial sites in intermetallic hydrides is proposed. The model assumes that the occupation numbers are determined by Boltzmann distribution function as well as by the heat of formation of the “imaginary binary hydrides” formed between the hydrogen atoms and the host metallic atoms forming the interstitial sites. Comparison of our calculations with recent neutron scattering data on various hydrides indicate good agreement at T=300 K.