The recently determined value of the quadrupole moment of ${\mathrm{Fe}}^{57m}$ has been shown to explain consistently the observed quadrupole coupling constants associated with two non-equivalent Fe sites in yttrium iron garnet.

On the basis of the Strutinsky shell-correction method applied to realistic diffuse-surface potentials we have calculated the shape of the island of superheavy nuclei. With respect to spontaneous fission, the island is a mountain ridge extending from 114 protons to about 124 protons. The descent from the mountain down to the sea of instability is rather gentle for decreasing neutron numbers below 184, but is more rapid on the other three sides.

A new high-spin isomer ${}_{}{}^{177m_2}{}_{}{}^{}\mathrm{Hf}$ has been produced via the reactions ${}_{}{}^{176}{}_{}{}^{}\mathrm{Yb}(\alpha ,3n){}_{}{}^{177}{}_{}{}^{}\mathrm{Hf}$ and ${}_{}{}^{186}{}_{}{}^{}\mathrm{W}(p,p\alpha 5n){}_{}{}^{177}{}_{}{}^{}\mathrm{Hf}$. It is interpreted as a $K^{\pi }={\frac{37}{2}}^{-}$ five-quasiparticle state. Seven $\gamma$ rays attributed to the decay of this new isomer, and the $\gamma$ radiation from 1.1-sec ${}_{}{}^{177m_1}{}_{}{}^{}\mathrm{Hf}$ in equilibrium, decayed with a (51.6 ± 1.6)-min half-life. These $\gamma$ rays result from de-excitation of an isomeric level in ${}_{}{}^{177}{}_{}{}^{}\mathrm{Hf}$ at 2739.7 keV to the rotational band members of the $K^{\pi }={\frac{23}{2}}^{+}$ isomeric state.

We present data on the differential cross section for the reaction ${\pi }^{-}p\to {\pi }^{+}\Delta {\mathrm{}\left(1236\right)\mathrm{}}^{-}$ for ${\pi }^{+}$ scattered backward near 180°, $-0.002>u-u_{max}\gtrsim -0.09\mathrm{}$ ${(\mathrm{G}\mathrm{e}\mathrm{v}/\mathit{c})}^2$, with incident ${\pi }^{-}$ beam momenta between 2.15 and 6 GeV/c. The differential cross section exhibits a sharp backward dip which appears to persist over this range of incident momenta.

A new parton model is defined. Two predictions are obtained for deep-inelastic $e-p$ scattering: (1) At an inyariant momentum transfer $-Q^2$ of 1 ${\mathrm{GeV}}^2$, at least half the final states will contain a $K$ meson. (2) For a value of $-Q^2$ somewhere between 8 and 30 ${\mathrm{GeV}}^2$ the Bjorken scaling prediction will be violated and a large fraction of the final states will contain an antibaryon.

We show that the squared coupling constant ${\eta }_{\mathrm{PPP}}\mathrm{}\left(t\right)\mathrm{}$ connecting three Pomeranchukons, which has acquired considerable interest recently, can be evaluated directly from experiment. We use data at 24 GeV/c for the reaction $p+p\to p^{+}$ background for this purpose. We find that ${\eta }_{\mathrm{PPP}}\mathrm{}\left(0\right)=0.005\mathrm{}$ is consistent with theoretical estimates. Further, ${\eta }_{\mathrm{PPP}}\mathrm{}\left(t\right)\mathrm{}$ falls very rapidly at $t$ goes from 0 to -1.5 ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$.

The hypothesis of leading light-cone singularity dominance is examined for vertex functions in the so-called $A$ limit with $\omega =1\mathrm{}$ and for scattering amplitudes in the Regge limit. It is shown that, in the field expansion, terms less singular on the light cone must be as important asymptotically as the more singular terms, unless the asymptotic behavior changes abruptly when an external leg goes slightly off the mass shell.

Semiclassical radiation theory provides parallel derivations of spontaneous emission and of spontaneous incoherent scattering of radiation. In the latter case, in constrast to the former, the theory is in clear disagreement with established experimental data since it predicts equal intensity for Stokes and anti-Stokes lines in Raman scattering. A new postulate of semiquantization is proposed to restore agreement with experiment without quantizing the electromagnetic field.

It has been found that nuclear reaction recoils ejected from a target and thermalized in helium attach to large molecular clusters produced from impurities by the intense ionization generated by the beam passing through helium. When the clusters containing the recoils are entrained in a room-temperature sonic helium flow, they attain kinetic energies of up to 700 keV on account of their high molecular weights which were found to be as high as ${10}^8$ u. Highly efficient separations of nuclear reaction recoils from helium carrier gas have been achieved as a result of the formation of these large clusters.

The exactly solvable Baker-Essam model for a compressible Ising lattice is re-examined. We find that, depending on the type of constraint imposed upon the system, the second-order phase transition either gets renormalized or is changed into a first-order transition. We resolve the apparent disagreement of this result with Fisher's renormalization theory by showing that, in fact, our result is typical of the correct state of affairs to be expected on the basis of the general theory of critical points in systems with hidden variables.

Experiments are reported which show that the electrical birefringence of the isotropic phase of two nematic liquid crystals depends on electrical conductivity. It is argued that the conduction-induced alignment is due to local conduction anisotropy.

The helical twisting power in nematic ($\mathrm{methoxybenzylidene} p-\mathrm{aminophenyl}\mathrm{acetate}$)-cholesteric (cholesteryl propionate) mixtures as a function of cholesteric material concentration is studied by measuring the circular dichroism, the wavelength of selective reflection, and the Grandjean fringes. It is found that as the cholesteric material concentration increases, the twisting power of the mixtures increases linearly up to a certain concentration, beyond which, however, it increases more slowly, taking a maximum value at some specific concentration which normally falls in the high-concentration region.

The soft-x-ray absorption spectrum from the Si $L_{\mathrm{II},\mathrm{III}}$ shell is used to study several energy-band models for Si. The calculations are based on the empirical pseudopotential method. The results support the recent Si band model obtained by Stukel, Euwema, and Chaney, Lin, and Lafon. We suggest that the ${\Gamma }_{2^{\prime }}$ level lies below ${\Gamma }_{15}$ in the Si conduction band.

Experimental evidence is presented for the existence of both the volume and surface photoelectric effects in aluminum. Good agreement is obtained between the observed strengths of the surface effect and the predictions of the Mitchell-Makinson theories when the photoemission due to surface plasmon decay is divided into surface and volume photoeffect components.

We have observed that the normalized tunnel conductance $\frac{{\left(\frac{\mathrm{dI}}{\mathrm{dV}}\right)}_S}{{\left(\frac{\mathrm{dI}}{\mathrm{dV}}\right)}_N}$ of Si-Pb junctions shows a strong dependence on the electron concentration of the bulk Si electrodes. The phonon-induced structure in the tunneling density of states of superconducting Pb is enhanced in the data with Pb positively biased and is suppressed in the data with Pb negatively biased. These enhancement and suppression effects increase with decreasing electron concentration in Si.

By using optical methods to detect paramagnetic resonance signals from triplet excitons and from trapped triplet excitations in benzophenone, we have shown that spin angular momentum is conserved in triplet-triplet energy transfer.

The annihilation rate of positrons in the alkali metals has been measured at room temperature for pressures up to 55 kbar. The observed departure from simple predictions of the free-electron gas model are explainable on the basis of changes in the fraction of core annihilations. This interpretation is not, however, consistent with the changes in the Doppler-broadened line shape.

The first observation of the resolved fine-structure splitting of a localized moment in a metal is reported in the EPR spectrum of single-crystal dilute Au:Gd alloys. A theory of line narrowing of fine-structure lines from spin-spin couplings and localized-conduction electron exchange is developed. The narrowing distorts the observed resonance line shape, and is essential to the extraction of the fine-structure splitting parameter: $b_4=-20\mathrm{}\pm 1$ G.

Temperature-dependent hyperfine-field studies of FeSi and FeMn alloys show that ferromagnetism in iron is a result of long-range exchange interactions, coupling largely localized magnetic moments. This long-range exchange is probably due to the partially itinerant character of the $3d$ electrons.

A new theory based on the coherent-potential approximation is presented for the spin susceptibility $\chi$ in disordered binary alloys having arbitrary concentration and scattering-potential strengths. In the dilute-alloy limit the susceptibility contains all formerly derived expressions for $\chi$ as well as new physically significant terms. In the weak-scattering limit, an extension of the local-exchange-enhancement model is obtained which can be satisfactorily applied to nondilute Pd-Pt.