The anisotropy, lifetime, and fluctuations of the cosmic rays are considered for a model in which the cosmic-ray sources are random discrete events in space-time.

We have found a bubble-chamber picture which shows three contemporaneous high-energy cosmic-ray tracks. One of the tracks has ionization which is that expected of a charge-$\frac{2}{3}$ particle if the mass of this particle is less than 6.5 GeV. The observed ionization is also consistent with that which is expected of a charge-$\frac{1}{3}$ particle with a mass of 8.0±3.0 GeV.

A relationship between the frequency of the occurrence of starquakes on pulsars and the shear strength of the solid crust of these objects is derived assuming various mechanisms of damping of their rates of rotation. Tentative conclusions concerning the shear strength, the age, and the composition of the Crab and the Vela pulsars are made.

The production of the $A_1$ has been reported at 12.8 GeV/c in the reaction $K^{+}p\to Kp\left(3\mathrm{}\pi \right)$. It has also been reported at 9.0 GeV/c in the reactions $K^{+}p\to Kp\left(3\mathrm{}\pi \right)$ and $K^{+}p\to Kp\left(4\mathrm{}\pi \right)$. At 12.0 GeV/c, with five times the data of the 12.8-GeV/c experiment and three times the data of the 9.0-GeV/c experiment, we see no evidence for $A_1$ production in any of these reactions.

Evidence is presented for a new effect in ortho-para ${\mathrm{H}}_2$ conversion on magnetic solid surfaces at low temperature. This effect is a resonant exchange of energy between the spins of the magnetic impurities and ${\mathrm{H}}_2$ molecules which are absorbed in their vicinity. This process could explain the strong activities of many catalysts.

We have measured the energy dependence of the 4610- and 4765-Å lines of ${\mathrm{Ar}}^{+}$ excited in low-energy ${\mathrm{He}}^{+}$ +Ar collisions from threshold to 700 eV ${\mathrm{He}}^{+}$ energy. The 4610-Å line rises sharply with energy to a peak near threshold, while the rise of the 4765-Å line is more gradual than previously reported and than most other lines excited in this process. The 4765-Å line still shows, however, a much lower energy peak than predicted by the adiabatic hypothesis. The threshold behavior of the 4610- and 4765-Å lines appears to be typical of lines emitted from levels with ${}_{}{}^1{}_{}{}^{}D$ and ${}_{}{}^3{}_{}{}^{}P$ parent terms, respectively.

A general kinetic theory of intercollisional interference effects has been developed. Applied to collision-induced light scattering in rare gases, it predicts a peak at the incident frequency, with a height of about 25% of the intracollisional peak and a width proportional to the density.

Modulation coupling between electron upper-hybrid modes and ion modes propagating nearly perpendicular to the axial magnetic field is shown to be effective in collisionless and semicollisionless regimes. A complete probeless feedback stabilization scheme based on such mode coupling is described.

Measurements of the dielectric loss in a liquid crystal, exhibiting both nematic and smectic phases, show an ordering with the long axes of the molecules preferring a direction papallel to both dc and 5000-Hz electric fields in the nematic phase. In the smectic phase the preferred direction is parallel to a 5000-Hz electric field and perpendicular to a dc field. The observed alignment of the smectic phase in a dc field is believed to be anomalous and it is suggested that this effect may be associated with the conductivity anisotropy.

A careful look at the data on the specific-heat anomaly in bcc solid ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ reveals that it disagrees in temperature dependence and concentration dependence with the theory recently proposed by Varma.

Superconductivity has been observed in a high-pressure phase of cesium. Yttrium, normal at zero pressure down to millidegree temperatures, shows pressure-induced superconductivity above 110 kbar, apparently without change in crystal structure. Superconductivity, once restricted to the puzzling case of lanthanum in this part of the periodic system, turns out to be the general phenomenon when we apply pressure.

If only nearest-neighbor quadrupole-quadrupole couplings are included in a rigid-lattice model of fcc solid ortho-${\mathrm{H}}_2$, the usually assumed $\mathrm{Pa}3\mathrm{}$ order is stable only at the lowest temperatures, and an order with space group $\mathrm{Cmmm}$ is stable at higher $T$. This $\mathrm{Cmmm}$ order is destabilized by inclusion in the model of as little as 15% of the unshielded $\mathrm{QQ}$ coupling to second and other neighbors. Inclusion of second-neighbor interactions in the model seems necessary and sufficient to eliminate spurious qualitative behavior, and to make appropriate a libron theory starting from the assumption of $\mathrm{Pa}3\mathrm{}$ order.

Under appropriate experimental conditions helicon waves can propagate in semimetals. The region of strong helicon-phonon coupling occurs at rather low magnetic fields, and this coupling can strongly influence the direct generation of sound.

We report a new type of pair-line spectrum, namely, the recombination of a double neutral donor with a shallow neutral acceptor. An isotope shift in this pair-line spectrum proves that the acceptor is lithium. This identification, together with the results of chemical doping experiments, provides strong evidence that the $I_1$ lines in CdS are due to Li and Na.

Cyclotron-resonance studies of silver have revealed two additional series of oscillations, one between the fundamental and the second harmonic, the other above the fundamental resonance. These series are caused by the excitation of weakly damped discrete-spectrum waves propagating perpendicular to the static magnetic field.

We have measured the Brillouin spectrum of LiF at hypersound frequencies in the [100] and [110] planes. In addition to the longitudinal mode we have observed the pure transverse modes in these planes. Both the polarization and the relevant intensities confirm the assignment. The measured elastic constants are compared with ultrasonic data.

A microscopic interpretation of ${\epsilon }_d$, the mean $d$-band energy in the Heine-Hubbard interpolation description of the transition metals, and of $\epsilon \left({\Gamma }_1\right)$, the bottom of the conduction bands, is given in terms of a "renormalized atom" concept. The implication for the cohesive energy of the transition metals is considered within the same framework and contrasted to the alkali metals.

The temperature variation of sublattice magnetization in the quadratic layer antiferromagnets ${\mathrm{K}}_2$Ni${\mathrm{F}}_4$ and ${\mathrm{K}}_2$Mn${\mathrm{F}}_4$ has been determined by measuring the NMR frequency of out-of-layer ${}_{}{}^{19}{}_{}{}^{}\mathrm{F}$ nuclei in these compounds. The results are found to agree with a simple two-dimensional spin-wave theory for $T\lesssim \frac{T_{\mathrm{N}}}{2}$, with $T_{\mathrm{N}}=\mathrm{N}\acute{\mathrm{c}}\mathrm{eel} \mathrm{temperature}$. Some evidence is found for residual exchange coupling between second-neighbor layers in ${\mathrm{K}}_2$Ni${\mathrm{F}}_4$; upper limits for such coupling are set. Evidence is also presented for a large zero-point spin reduction in ${\mathrm{K}}_2$Ni${\mathrm{F}}_4$.

Strange asymmetries observed in magnetic neutron guides are explained in terms of an additional surface current due to the spin-orbit interaction of the neutrons in the Coulomb field of the atoms. This result enhances the approach of the index of refraction for the total reflection of neutrons using the propagator of the Schrödinger equation.

${}_{}{}^{44}{}_{}{}^{}\mathrm{Ca}$ was found to show both a smaller shift and width than ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ for the $3d-2p$ pionic-atom x-ray transition. From this measurement and an optical-model analysis, it can be deduced that the neutron distribution at the surface of the ${}_{}{}^{44}{}_{}{}^{}\mathrm{Ca}$ nucleus extends significantly beyond the proton distribution.