Detailed field- and frequency-dependent conductivity measurements are reported in ${\mathrm{}\left(\mathrm{TMTSF}\right)\mathrm{}}_2$P${\mathrm{F}}_6$. No threshold field and a small dielectric constant are found, implying the absence of restoring forces. No evidence is found for wide- or narrow-band noise in the nonlinear regime. This, together with the preliminary observation of a high mobility, suggests that single-particle effects are largely responsible for the nonlinear conductivity below the transition.

A large resonance was observed in the $\mathrm{C}\mathrm{}\left(1s\right)\mathrm{}$ angle-resolved photoemission cross section of CO overlayers on Ni(111) and Ni(001), with use of synchrotron radiation at the Stanford Synchrotron Radiation Laboratory, while none was observed for $\mathrm{O}\mathrm{}\left(1s\right)\mathrm{}$. Energy-, angular-, and polarization-dependence measurements showed that the $\mathrm{C}\mathrm{}\left(1s\right)\mathrm{}$ resonance, which is peaked at $h\nu =311\mathrm{}$ eV, is closely related to the shape resonance predicted for the $\mathrm{C}\mathrm{}\left(1s\right)\mathrm{}$ level in isolated CO. However, the surface potential introduces strong substrate-dependent deviations from gas-phase theory.

Metallic iodine in the high-pressure phase above $P_t=21\mathrm{}$ GPa is found to form a body-centered orthorhombic Bravais lattice. Hence, pressure-induced molecular dissociation takes place at $P_t$.

Nuclear magnetic resonance and dielectric susceptibility data are reported in KTa${\mathrm{O}}_3$: Li which show, for the first time, ordering of random-site electric dipoles in a nonpolar lattice.

The $T_c\mathrm{}\left(p\right)\mathrm{}$ vs $p$ phase diagram and the critical behavior of the magnetic susceptibility of the randomly diluted, three-dimensional, Ising, dipolar-coupled ferromagnet $\mathrm{Li}{\mathrm{Tb}}_p{\mathrm{Y}}_{1-p}{\mathrm{F}}_4$ has been measured for $0.97>~p>~0.46$. For $p>~0.46$ the $T_c\mathrm{}\left(p\right)\mathrm{}$ phase diagram obeys the relation $T_c\mathrm{}\left(p\right)=2.88\mathrm{} \mathrm{K}-(3.24\mathrm{}\pm 0.10 \mathrm{K})(1-p)\mathrm{}$. At small $p$, a power-law fit is found to be qualitatively more in agreement with the data than either the renormalization-group logarithmically corrected power law or a recent prediction for the random dipolar Ising magnet.

The rotational diffusion of rodlike $M-13\mathrm{}$ viruses in solution has been measured at concentrations intermediate between the dilute and the concentrated regimes. The strong concentration dependence observed is in agreement with the Doi-Edwards model based upon simple steric hindrance arguments between rotating rodlike macromolecules. The dependence of the rotational diffusion coefficient on the virus length has also been investigated.

An argument is presented for the validity of the quadrupole formula for gravitational radiation energy loss in the far field of nearly Newtonian (e.g., binary stellar) systems. This agrument differs from earlier ones in that it determines beforehand the formal accuracy of approximation required to describe gravitationally self-interacting systems, uses the corresponding approximate equation of motion explicitly, and evaluates the appropriate asymptotic quantities by matching along the correct space-time light cones.

A new derivation of the quadrupole formulas and balance equations of general relativity for gravitationally bound systems is given which overcomes objections raised to previous derivations.

Equilibrium polymerization can be described by the $n\to 0$ limit of the $n$-vector model of magnetism in a small magnetic field. Nonclassical critical effects are predicted. The earlier theory of Tobolsky and Eisenberg is a mean-field approximation to the present theory. An application is made to the polymerization in sulfur.

The decay rate for $\eta \to 3\pi$ is calculated with use of the $u_3$ tadpole piece of the quark Hamiltonian, but without assumptions of chiral perturbation theory. The calculation is performed within the framework of the bag model; however, the results are independent of bag parameters and depend only on (1) the light quark mass difference $|m_u-m_d|$ and (2) the quark structure of the $\epsilon \mathrm{}\left(700\right)\mathrm{}$. Comparison of the present calculated $\eta$ decay rate with experiment shows that most theoretical estimates of $m_u-m_d$ imply a substantial four-quark component in the $\epsilon \mathrm{}\left(700\right)\mathrm{}$.

Monte Carlo calculations of the specific heat of the four-dimensional SU(2) lattice gauge model show a sharp peak where Creutz discovered a crossover in the value of the string tension. In this region is also found a rapid increase in the correlation length and a slowing down in the Monte Carlo convergence towards equilibrium.

Transverse electron scattering form factors from the ground-state rotational band of ${}_{}{}^{181}{}_{}{}^{}\mathrm{Ta}$ have been measured to study the single-particle contribution to the magnetization current density. The data are compared with a Hartree-Fock calculation by use of density matrix expansion with filling approximation.

The interacting boson approximation has been applied to the deformed nucleus ${}_{}{}^{168}{}_{}{}^{}\mathrm{Er}$. The parametrization used corresponds to a description close to the SU(3) limit of the model. The calculation, which is the most detailed test of the interacting boson approximation to date, correctly reproduces the complete sequence of positive-parity collective bands below the pairing gap and provides an excellent overall description of their decay properties.

Double charge exchange is observed for the first time with heavy ions by using the reaction ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$(${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{14}{}_{}{}^{}\mathrm{O}$)${}_{}{}^{40}{}_{}{}^{}\mathrm{Ar}$ at 51 MeV incident energy. Angular distributions for the rearrangement-transfer reaction ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$(${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{15}{}_{}{}^{}\mathrm{O}$)${}_{}{}^{39}{}_{}{}^{}\mathrm{Ar}$ were also measured, and both exotic reactions are compared with the more usual one- and two-proton transfer reactions (${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{15}{}_{}{}^{}\mathrm{N}$) and (${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$). Cross sections for the exotic processes are surprisingly large: ∼10 μb/sr for (${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{14}{}_{}{}^{}\mathrm{O}$) and ∼200 μb/sr for (${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{15}{}_{}{}^{}\mathrm{O}$).

Angular distributions of the analyzing power $A\left(\theta \right)$ and the differential cross section $\frac{d\sigma \left(\theta \right)}{d\Omega }$ for the reaction ${}_{}{}^9{}_{}{}^{}\mathrm{Be}$($p_{\mathrm{pol}}$, ${\pi }^{-}$)${}_{}{}^{10}{}_{}{}^{}\mathrm{C}$(g.s.) have been measured with 200-MeV polarized protons at laboratory angles between 25° and 150°. The measured $A\left(\theta \right)$, which is negative for ${{\theta }_{\pi }}^{\mathrm{c}.\mathrm{m}.\mathrm{}}\lesssim 70°$ and positive thereafter, is quite different from those of ($p_{\mathrm{pol}}$,${\pi }^{+}$) reactions, for which $A\left(\theta \right)$ is typically negative at all angles. The present $\frac{d\sigma \left(\theta \right)}{d\Omega }$ is backward peaked, unlike all previously measured ($p$,${\pi }^{-}$) distributions.

Previously reported differences between the measured proton and neutron energy spectra for the reaction ∼400 MeV/nucleon ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$+$\mathrm{U}\to p$,$n+X$ are discussed. A parameter-free cascade-coalescence model of heavy-ion collisions is shown to account for these differences. Such measurements are shown to be sensitive to the degree of projectile-target equilibration in relativistic nuclear collisions.

It is shown that low-energy deuteron photodisintegration data provide evidence that the traditional view of the $\mathrm{NN}$ interaction mediated by the exchange of mesons between two almost-point nucleons breaks down for a separation distance of less than about 1.5 fm. The discrepancy can be remedied by a phenomenological modification of the theory in which the extended nature of the nucleon is explicitly recognized.

Highly resolved spectra are presented which show how the low-magnetic-field energy-level structure of a single-electron atom gives rise to the quasi-Landau resonances as the field is increased. Data from the strong-mixing region where electric and magnetic forces are comparable reveal that evenly spaced energy levels are a general feature, irrespective of parity and magnetic quantum number of the states. The quasi-Landau resonances emerge by a concentration of oscillator strength into a single level of each term.

Experimental potentials for the $X{}_{}{}^2{}_{}{}^{}\Sigma _{}^{+}{}_{}{}^{}$ and $A{}_{}{}^2{}_{}{}^{}\Pi$ states of the NaHe molecule are presented. The potentials are generated from the temperature dependence of the red wing of the Na resonance line perturbed by He. For the $A{}_{}{}^2{}_{}{}^{}\Pi$ state an unexpectedly large value is obtained for $D_e=480\mathrm{}\left(50\right)\mathrm{}$ ${\mathrm{cm}}^{-1\mathrm{}}$ at $R_e=4.4\mathrm{}\left(2\right)\mathrm{}{a}_0$. The physical basis for this result, which indicates an important role for the internal structure of the rare gas in determining the repulsive part of the alkali-rare-gas interaction, is discussed.

Amplification of millimeter-wave electromagnetic radiation within the cathode region of a cold-cathode glow discharge is reported. A model based on stimulated emission of bremsstrahlung is suggested.