Microphysical nonseparability and relativistic signals

Bell's proof and recent experiments sugested by it raised questions concerning the existence of supraluminal influences and the status of these with respect to Einstein's theory of relativity. These questions are briefly examined via an approach which is independent of any model. This approach generates a clear distinction between information perceivable by an observer, which is found to be transmited with infraluminal speed and influences acting inside the microphenomena. An informational treatment gives a quantitative indication concerning acting information.     

Rearrangement thermique des adduits du tetracyanoethylene de 2H-pyrannes

The addition of tetracyanotehylene to 2H-pyrans 1 results in a mixture of two isomeric adducts 6. The thermal decomposition of the compounds 6 gives rise to both a small percentage of the retro Diels-Alder, and a new mode of evolution leading to a mixture of furans (E+Z) 7. A detailed interpretation of the ¹³C spectra of the compounds 7 was established by comparison with the ¹³C spectra of 2,5-diphenylfuran and trans-stilbene. The structure 7 is confirmed by chemical degradation.     

Autour du théorème de Stein-Rosenberg

Summary The aim of this note is to present a synthesis of recent applications or extensions of the Stein-Rosenberg theorem on nonnegative matrices: convergence ofnon linear iterative process; truncated, or chaotic, or boolean Stein-Rosenberg theorems.The conclusion is the following: As it works through various mathematical contexts, the Stein-Rosenberg theorem expersses a rather deap idea of an essentially algorithmic nature.     

A charge-dependent three-nucleon potential

Using the p-wave part of the charge asymmetric three-nucleon potential we calculate the charge asymmetric binding energy in ³He³H nuclei. The total contribution which arise from the electromagnetic corrections to the three-nucleon potential turns out to be negligble.     

Anderson localization for one- and quasi-one-dimensional systems

We prove almost-sure exponential localization of all the eigenfunctions and nondegeneracy of the spectrum for random discrete Schrödinger operators on one- and quasi-one-dimensional lattices. This paper provides a much simpler proof of these results than previous approaches and extends to a much wider class of systems; we remark in particular that the singular continuous spectrum observed in some quasiperiodic systems disappears under arbitrarily small local perturbations of the potential. Our results allow us to prove that, e.g., for strong disorder, the smallest positive Lyapunov exponent of some products of random matrices does not vanish as the size of the matrices increases to infinity.     

Spectral density of surface states: Clean W(001) surface

The transfer matrix approach is applied to calculate the spectral density of electronic states for the W(001) surface. We use a tight-binding hamiltonian with a nine function basis: 6s, 6p and 5d. Results for $\text{k}$ points along the Σ and ? symmetry lines are presented for occupied states. Both surface and bulk features of the spectral density are in good agreement with angularly resolved photoemission spectra.     

Solution properties and unperturbed dimensions of poly(p-tert-butylstyrene)

The conformational and thermodynamic properties of poly(p-tert-butylstyrene) were investigated by osmometry, intrinsic viscosity, light scattering, gel permeation chromatography and phase equilibria measurements. Polymeric samples were anionically synthesized. 1-Nitropropane was found to be a θ-solvent for this polymer and the θ-temperature was determined as 31°C. Intrinsic viscosity-molecular weight relationships were obtained in a few solvents. Unperturbed dimensions, estimated from both viscosity and light scattering results, led to the characteristic ratio, C_α, of 13.4 ± 0.7 at 31°C. Comparison of this value with those for other polystyrene derivatives shows that the characteristic ratio increases with the bulkiness of the side-group due to the steric effect.