U wire samples under very high confining gas pressures are heated Ohmically into the liquid phase. The sample diameter is measured after achievement of thermodynamic equilibrium. Enthalpy-volume isobars and resistivity-enthalpy curves are obtained. The data are fitted with a soft-sphere theory of liquids, and the critical point of U is estimated.

Probability distributions for Fourier components of the electric field, including joint distributions for different Fourier components and multiple-time distributions for the same component, are determined using two assumptions within the spirit of weak-turbulence theory. This statistical framework is then applied to the special case where the turbulence is dominated by the wave-particle interaction (i.e., the quasilinear case).

Laser-radiation scattering is proposed as a method for measuring impurities in tokamak or toroidal pinch plasmas. A direct measurement of the effective charge for momentum transfer, $\overline{Z}$, appears feasible by this technique.

A systematic study is made of the efficiency of first-harmonic ion-cyclotron heating in hot, dense, large plasmas. Promising heating times are derived when the imposed axial wavelength satisfies the rather restrictive high-temperature, high-density limitation $k_z>~{{\omega }_{\mathrm{pi}}}^2{V}_i{{\omega }_{\mathrm{ci}}}^{-1\mathrm{}}{c}^{-2\mathrm{}}$.

The linear combination of muffin-tin orbitals technique has been used to calculate the electronic energy levels of a five-layer Cu (001) film. We do not find any surface states in the $s-d$ gap as had been predicted and calculated in other theoretical studies. Instead we find the energy levels to be nearly indistinguishable from those of the bulk crystal, which agrees with ion-neutralization-spectroscopy data on Cu crystals and with photoemission data from thin overlayers of Cu on Ag substrates.

Soft-x-ray appearance-potential spectra of rare-earth elements are interpreted in terms of strong resonance interactions between the incident electrons and atomic $4f$ states. These interactions account for both the large intensity and the threshold shifts of the measured signal. This resonance persists in La, Ce, Pr, and Nd when present as only a few atomic percent in a NiCr alloy reflecting the local character of the interaction.

New pseudopotential calculations of the densities of states of trigonal Se and Te (in excellent agreement with recent photoemission measurements) are used to show that two easily resolved peaks in the photoemission data are directly related to interchain and intrachain bonding. This identification is accomplished by calculating electronic charge densities as a function of energy for different energy regions. Finally we introduce a new method for determining bonding charges by extracting short-wavelength components of the electronic charge density.

Low-temperature electrical resistivities of Pd-Ag alloys show a positive $T^2$ temperature dependence in the concentration range above 60 at.% Ag. This behavior supplements the well-known resistivity minima observed in alloys with lower concentrations of Ag, and strongly favors the model of scattering from localized exchange-enhanced Pd $d$ states, as against $s\to d$ scattering in the rigid-, or collective-, band description of the alloys.

The electronic structure of an isolated TCNQ mulecule has been calculated by the self-consistent statistical-exchange multiple-scattering method. By using overlapping atomic spheres in place of nonoverlapping atomic spheres, a significant increase in physical realism has been achieved. The theoretical model provides a satisfactory account of the photoemission spectra of TCNQ vapor and solid TCNQ. The singlet-triplet splitting for the lowest optical transition is found to be 0.84 eV.

The field dependences of the magneto-optical rotation of the two time-reversed states of antiferromagnetic dysprosium aluminum garnet show significant differences. These are interpreted in terms of the spatial variation in the signs of the spin-spin interactions demanded by the crystal symmetry. The coexistence of the two time-reversed states has been studied by microscopy made possible by the rotation difference and also by a striking "decoration" of the domain walls by paramagnetic nuclei.

The noncharacteristic radiation observed in heavy-ion bombardment of Si was investigated with 200-keV ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$, ${}_{}{}^{35,37}{}_{}{}^{}\mathrm{Cl}$, ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ar}$, ${}_{}{}^{39,41}{}_{}{}^{}\mathrm{K}$, ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$, and ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ti}$ projectiles ($16<~Z<~22$) on Si. The high-energy tail of the noncharacteristic radiation is observed to shift to higher energies as projectile $Z$ is increased. The observed end-point energy shifts are in agreement with the interpretation that the radiation arises from the radiative decay of a projectile $2p$ vacancy in the quasimolecule formed by the projectile and the target atom during the collision.

When the donor spins in $n$-CdS are simultaneously irradiated with laser light at frequency ${\omega }_L$ and microwaves at frequency ${\omega }_0$ near the spin resonance, intense sidebands at ${\omega }_L\pm {\omega }_0$ are observed for forward scattering which are more than 3 orders of magnitude greater than those for spontaneous spin-flip Raman scattering. This phenomenon is explained as Raman scattering from coherent states.

By use of Kubo's statistical formalism, we show that the orientational fluctuations of interacting molecules are responsible for both the narrow central component and the broad Rayleigh-wing component in the light-scattering spectrum of a liquid crystalline material. The same formalism also describes the optical Kerr effect. We also point out the difference between the microscopic and the macroscopic order parameters.

The first measurements of longitudinal spin relaxation due to binary atomic collisions in bulk ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ gas are reported. At 4.2 K the data are fitted by the expression $\rho T_1=61\mathrm{}\pm 2$ sec g ${\mathrm{cm}}^{-3\mathrm{}}$ for densities $\rho$ such that $0.01<\mathrm{}\rho <0.05\mathrm{}$ g ${\mathrm{cm}}^{-3\mathrm{}}$. At lower densities wall relaxation predominates and at higher densities a binary collision theory is inadequate. A model of wall relaxation is given which identifies the role of the absorbed phase of ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ on the wall.

Two-scale-factor universality is used to show that a simple combination of measurable critical amplitudes is universal. Good experimental agreement is observed.

The observed dependence of the $\frac{1}{f}$ noise in metal films on the temperature coefficient of resistance and on sample volume, and the observation of frequency-dependent spatial correlations of the noise, suggest the noise is due to a thermal-diffusion mechanism. The assumption of a spectrum for the intrinsic temperature fluctuations with an explicit $\frac{1}{f}$ region, and the condition $〈{\left(\Delta T\right)}^2〉=\frac{k{T}^2}{C_V}$, yield quantitative predictions of the noise power in excellent agreement with experiment.

Interactions between strongly correlated electrons (or holes) and spin waves are investigated with the aid of a simple physical model. The model is the large-interaction limit of the Hubbard model with an additional ferromagnetic Heisenberg interaction between nearest-neighbor singly occupied sites. We find that even though there is no obvious electron-magnon attraction in the model, electron-magnon bound states exist for some crystal structures.

Anomalous $\frac{\epsilon }{{\beta }^{+}}$ decay branching ratios for "hindered allowed" transitions (measured by ${\gamma }^{\pm }-\gamma$ and x-$\gamma$ coincidence techniques) have been found in ${}_{}{}^{145g}{}_{}{}^{}\mathrm{Gd}\to {}_{}{}^{145}{}_{}{}^{}\mathrm{Eu}(808.5-\mathrm{keV}\mathrm{state})$ and ${}_{}{}^{143g}{}_{}{}^{}\mathrm{Sm}\to {}_{}{}^{143}{}_{}{}^{}\mathrm{Pm}(1173.2-\mathrm{keV}\mathrm{state})$. These ratios exceed theoretical predictions by factors of 24 and 5, respectively. Thirteen additional ratios from these nuclei and ${}_{}{}^{143}{}_{}{}^{}\mathrm{Eu}$ agree with the predictions. This is the first conclusive evidence of the failure of the allowed assumption in nuclear $\beta$ decay and of the presence of interference effects.

We report the first measurement of primary-cosmic-ray positrons above 5 GeV. Both $e^{+}$ and $e^{-}$ fluxes were measured, using a balloon-borne magnetic spectrometer. Background was suppressed using a new technique which combines both selective trigger and identification of bremsstrahlung photons created by $e^{\pm }$ upon entering the instrument. If no positrons originate at cosmic-ray sources, our observed ratio $\frac{e^{+}}{(e^{+}+e^{-})}=0.08\mathrm{}\pm 0.02$ requires source protons to traverse 3.5±1.5 g/${\mathrm{cm}}^2$ of interstellar material.

An examination is made of the dimensional analysis usually employed to solve the renormalization group equations for the asymptotic region. It is argued that if this analysis is done systematically, one must in general add new inhomogeneous terms to the asymptotic equations even after invoking Weinberg's theorem to discard the (generalized) mass insertion term. These new inhomogeneities are entirely determined by the physical thresholds of the theory. They are shown to provide a natural explanation of Bjorken scaling in interacting field theories.