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.     

NMR study of catechol and some catecholamines

The proton magnetic resonance spectra of catechol, epinephrine, dopamine, synephrine, tyramine and amphetamine have been analysed by computer simulation. The chemical shifts and coupling constants are discussed, with their molecular implications. Convenient parameters are introduced for the additivity of substituent effects on chemical shifts of aromatic protons. The additivity rule of coupling constants is extended to these compounds.     

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.     

Elastic constant pressure derivatives and stability of the bcc phase of InTl alloys

Hydrostatic-pressure derivatives of the elastic stiffness constants have been measured ultrasonically in a bcc InTl alloy of composition near the eutectoid. The shear modulus $\text{1}\text{2}\text{(C}{}_{11}\text{?C}{}_{12}\text{)}$ is small, but does not soften under pressure: the eutectoid reaction is not directly associated with a mode softening shear instability. Anharmonic contributions to the excess vibrational entropy from the q 〈110〉, e 〈1$\text{1}$0〉 modes which stabilize the bcc structure are small compared with the harmonic contributions.     

Acceleration by aggregation of successive approximation methods

Methods of successive approximation for solving linear systems or minimization problems are accelerated by aggregation-disaggregation processes. These processes, which modify the iterates being produced, are characterized by a two directional flow of information between the original higher dimensional problem and a lower dimensional aggregated version. This technique is characterized by means of Galerkin approximations, and this in turn permits analysis of the method. A deterministic as well as probabilistic analysis is given of a number of specific aggregation-disaggregation examples. Numerical experiments have been performed, and these confirm the analysis and demonstrate the acceleration.