The magnetic hyperfine splitting of ${}_{}{}^{195m}{}_{}{}^{}\mathrm{Pt}\mathrm{}\left(\mathrm{Fe}\right)\mathrm{}$ was determined by the technique of nuclear magnetic resonance on oriented nuclei as $\frac{\mu H}{\mathrm{hI}}=89.5\mathrm{}\pm 0.5$ MHz. With additional $\gamma$-ray anisotropy data for the 129- and 99-keV $\gamma$ rays, we derived the spin, $I=\frac{13}{2}$, and the magnetic moment of the isomeric state, $\mu \left(\frac{13}{2}\right)=\pm (0.597\mathrm{}\pm 0.015){\mu }_N$, as well as the $\frac{E2\mathrm{}}{M1\mathrm{}}$ mixing ratio of the 99-keV $\gamma$ transition, $\delta =-0.16\mathrm{}\pm 0.02$.

Very quiet, steady-state plasmas in axial magnetic fields with density fluctuations less than 0.1% may be produced in a beam-plasm discharge. The dependence of the density and electron temperature on the discharge parameters are in accordance with the predictions of a one-dimensional plasma model.

Ultrasonic and Brillouin absorption and velocity data along the critical isochore in xenon are reinterpreted in terms of modified theoretical expressions derived within the framework of the Fixman-Mistura theory. The new expressions mainly arise from avoiding the unjustified assumption of small dispersion near a liquid-gas critical point. Numerical analysis of the data shows quite satisfactory agreement between theory and experiment for both sound absorption and dispersion.

Specific heats of ${\mathrm{He}}^4$ monolayers on graphite indicate two-dimensional solid phases. Debye temperatures $\Theta$ range from 17.6° to 56° systematically with coverage. Anomalies are identified with melting, but the melting process is a continuous transition. Films and bulk solid ${\mathrm{He}}^4$ at equal values of interatomic spacing have nearly the same $\Theta$'s and melting temperatures.

Stabilization of the two-stream instability in a weakly ionized plasma (equatorial electrojet) is studied using fluid equations. It is shown that a macroscopic quasilinear process acts to reduce the electron flow to a threshold level (ion sound speed), thereby stabilizing the instability. This result gives an explanation of constant Doppler shifts of radar echoes in the electrojet. It is further shown that the saturation level of the fluctuations agrees with that of observations.

When an electric field is applied perpendicularly to a cholesteric planar texture, periodic perturbations arise. The frequency dependence of the threshold of this instability is reported for nematic-cholesteric mixtures with both positive and negative dielectric anisotropy. In the latter case a "conduction" and a "dielectric" regime are observed, as in nematics. Our results are in agreement with a recent extension to ac excitations of Helfrich's theories for cholesterics.

The electron work function was measured by the Fowler method for four faces of a copper single crystal. The crystal was cleaned by repeated cycles of ion bombardment and annealing at 700°C under ultrahigh vacuum conditions. With uncertainties of $\delta \Phi =\pm 0.03$ eV, the work functions were found to be ${\Phi }_{110}=4.48\mathrm{}$ eV, ${\Phi }_{112}=4.53\mathrm{}$ eV, ${\Phi }_{100}=4.59\mathrm{}$ eV, and ${\Phi }_{111}=4.94\mathrm{}$ eV.

The polar magneto-optic Kerr effect of ${\mathrm{Bi}}_{0.8}$${\mathrm{Ca}}_{2.2}$${\mathrm{Fe}}_{3.9}$${\mathrm{V}}_{1.1}$${\mathrm{O}}_{12}$ has been measured between 0.5 and 0.24 μm. A strong magneto-optical transition is found at 0.47 μm which is not observed in ${\mathrm{Y}}_3$${\mathrm{Fe}}_5$${\mathrm{O}}_{12}$. This transition is concluded to be the origin of the anomalous large Faraday rotation of ${\mathrm{Bi}}_x{\mathrm{Ca}}_{3-x}{\mathrm{Fe}}_{3.5+0.5x}{\mathrm{V}}_{1.5-0.5x}{\mathrm{O}}_{12}$ recently reported and is interpreted as a charge transfer of an electron from an oxygen $p$ orbital to an antibonding $e$ orbital of the tetrahedral iron complex. The large rotation is attributed to a mixing of O and Bi orbitals.

By an accurate analysis it is demonstrated how Fukuda's model, which is based on the coexistence of two kinds of minima on the ${}_{}{}^3{}_{}{}^{}T_{1\mathrm{u}}^{}{}_{}{}^{}$ and ${}_{}{}^3{}_{}{}^{}A_{1\mathrm{u}}^{}{}_{}{}^{}$ adiabatic potential-energy surfaces, is not tenable in the framework of Russell-Saunders coupling. A generalized calculation to the intermediate-coupling case shows that two kinds of minima can coexist on the ${}_{}{}^3{}_{}{}^{}{T}_{1u}_{}^{*}{}_{}{}^{}$ adiabatic potential-energy surfaces if the spin-orbit interaction is of a suitable value as compared with the Jahn-Teller interaction and the exchange energy.

The magnetic properties of DySb have been studied using specific-heat, susceptibility, and neutron scattering techniques. It is found that there is a single first-order magnetic phase transition with a marked lattice distortion at 9.5 K. This result is in disagreement with the recent work claiming successive structural (quadrupole) and magnetic phase transitions at 11.5 and 9.5 K, respectively.

A new phase, most probably antiferromagnetic, is revealed in Invar at high pressures by Mössbauer experiments. In ${\mathrm{Fe}}_{0.70}$${\mathrm{Ni}}_{0.30}$ the Néel temperature has a slope of +1.9±0.3°K/kbar with a zero-pressure intercept of - 41 ± 21°K.

We find that over thirty solids having high one-dimensional conductivity form a class of materials whose electronic properties are determined principally by structural disorder.

A Thomas-Fermi approach is used to investigate the importance of the nuclear density distribution on pre-equilibrium decay. Two different density-dependent phenomena are pointed out, and both are shown to be equally important in modifying and improving pre-equilibrium decay predictions with respect to earlier models in which average density distributions were assumed.

Accurate measurements have been made of the analyzing power for the reaction $\mathrm{T}\mathrm{}(p,d)\mathrm{}\mathrm{D}$ which are equivalent to proton polarizations from $\mathrm{D}\mathrm{}(d,p)\mathrm{}\mathrm{T}$. If allowance is made for the reaction $Q$-value difference between $\mathrm{D}\mathrm{}(d,p)\mathrm{}\mathrm{T}$ and $\mathrm{D}\mathrm{}(d,n)\mathrm{}{}_{}{}^3{}_{}{}^{}\mathrm{He}$, thus comparing the data at the same outgoing neutron and proton energies, the polarizations are identical. This agreement eliminates much of the concern about charge-symmetry violation in the $d+d$ reactions.

Perturbed angular correlations were measured between 1.98-MeV $\gamma$ rays de-exciting the 3.3-psec $2^{+}$ state of ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$ and the ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}_{}^{*}{}_{}{}^{}$ particles following the reaction ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$(${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}_{}^{*}{}_{}{}^{}$)${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ at 33 MeV. A magnetic spectrometer was used to resolve the ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}_{}^{*}{}_{}{}^{}$ ions into the component $8^{+}$, $7^{+}$, and $6^{+}$ charge states, and the correlations were determined separately for each. The measurements yield information on hyperfine interactions in the $7^{+}$ and $6^{+}$ charge states. Limits are obtained on the ionic ground-state occupancies and on the value of the nuclear $g$ factor.

The giant $E1\mathrm{}$ resonances of ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ have been studied with the polarized-proton capture reactions ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}(p,{\gamma }_0){}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ and ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}(p,{\gamma }_1){}_{}{}^{12}{}_{}{}^{}\mathrm{C}$. The effects of proton polarization on the angular distributions were large and of opposite sign for ${\gamma }_0$ and ${\gamma }_1$. Coupled with the unpolarized measurements the polarized results produce additional significant limitations on the allowed configurations of the giant $E1\mathrm{}$ resonances in ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$.

Elementary arguments determine the operator superstructure for a special but broad class of covariant field theories. Field operators and generators of interest are shown to be bilinear expressions in conventional creation and annihilation operators. Nontrivial interaction is incompatible with canonical (anti) commutation relations.

A sensitive search was made for 2.64-mm line emission from a cloud of CN, whose excitation is known from optical measurements, with essentially a null result. This provides strong support for the proposition that the excitation temperature deduced from the optical CN lines is equal to the temperature of the microwave background.

We report an investigation of the production channels of the $A3\mathrm{}$ region of the ${\pi }^{-}{\pi }^{-}{\pi }^{-}$ mass spectrum from the reaction ${\pi }^{-}p\to p{\pi }^{+}{\pi }^{-}{\pi }^{-}$ at 13 and 20 $\frac{\mathrm{GeV}}{c}$. Evidence that the A3 has a substantial branching ratio to $3\pi$ is obtained; its mass and width are measured as 1658 ± 8 MeV and ${53}_{-16\mathrm{}}^{+20\mathrm{}}$ MeV, respectively. To satisfactorily describe the data an additional peak is required with mass 1830 MeV and width 130 MeV.

Antiprotron-deuteron inelastic-scattering differential cross sections have been measured near 1.8 $\frac{\mathrm{GeV}}{c}$. An impulse approximation is employed to extract antiproton-neutron differential cross sections. The technique allows us to study this reaction in a low-momentum-transfer region ($0.03<\mathrm{}\left|t\right|<0.15\mathrm{}$ Ge${\mathrm{V}}^2$) never explored before. Our data indicate that the real part of the antiproton-neutron forward scattering amplitude is consistent with zero. A comparison of antiproton-proton and anitproton-neutron differential cross sections confirms the previously reported crossover phenomenon in the region of the first diffraction minimum.