A way of resolving the difference between the Fermi-Landau and multiperipheral pictures of particle production is suggested. The basic observation is that if the Fermi-Landau fluid is already one-dimensional in the formation stage, then the entropy will be greatly reduced compared to the standard treatment. This allows the possibility for logarithmic growth with energy of the multiplicity, in agreement with the multiperipheral picture.

The differential cross sections for rotational, vibrational, and rotational-vibrational excitation by electron impact at 4.5 eV in ${\mathrm{H}}_2$ have been measured with a resolution of 18-22 meV. The cross-section ratio of pure vibrational excitation ($\Delta j=0\mathrm{}$) to rotational-vibrational ($j=1\mathrm{}\to 3$) excitation for $v=1, 2, \mathrm{and} 3$ shows the expected $p$-wave character. However, at a given angle of observation, this ratio decreases as the vibrational quantum number increases. This effect has not been predicted by theory.

It is shown that the Schrödinger equation for electronic wave functions can be modified so that its solutions describe a molecule as a collection of interacting atoms or other units. The interaction potential between electrons localized in different units is the weakest one possible that is consistent with the constraint that the corresponding localized wave function yield upon symmetry projection one solution to the Schrödinger equation. The binding energy of the system can be calculated directly.

This paper reports the polarization of the ${}_{}{}^{43}{}_{}{}^{}\mathrm{Ca}$ nuclei (natural abundance of 0.13%) in Ca${\mathrm{F}}_2$ by a three-step process: dynamic nuclear polarization of the ${}_{}{}^{19}{}_{}{}^{}\mathrm{F}$ nuclei, adiabatic demagnetization in the rotating frame of these spins, and finally rf thermal mixing, in an appropriate rotating frame, of the ${}_{}{}^{43}{}_{}{}^{}\mathrm{Ca}$ Zeeman energy with the nuclear dipolar interaction energy. In this way high polarizations up to (80 ± 15)% could be obtained, which made possible the direct observation by NMR of the ${}_{}{}^{43}{}_{}{}^{}\mathrm{Ca}$ nuclei in a 1-${\mathrm{mm}}^3$ sample.

In the presence of a magnetic field the ${}_{}{}^3{}_{}{}^{}\mathrm{He} A$ phase is interposed between the normal liquid and the ${}_{}{}^3{}_{}{}^{}\mathrm{He} B$ phase for all pressures measured, including pressures below that of the polycritical point. This can be understood on the basis of known nuclear paramagnetic properties if at a given pressure both ${}_{}{}^3{}_{}{}^{}\mathrm{He} A$ and ${}_{}{}^3{}_{}{}^{}\mathrm{He} B$ have the same critical temperature and if there are plausible small differences in the heat capacties of the two phases.

Self-phase modulation in a ${\mathrm{CO}}_2$-laser breakdown plasma is observed to down-shift the wavelength from 10.6 to about 10.0 μm. This results from the sudden drop in refractive index, from 1 to 0, which accompanies the ionization of the gas. The pressure dependence of this effect in nitrogen is opposite to that in helium.

A fast toroidal pinch with very small aspect ratio (2.6) is operated to test tokamak configuration. A narrow stability window appears between $q=1.3\mathrm{} \mathrm{and} 1.5$. In the stable region the energy loss from the plasma is mainly governed by the decay of the plasma current, which, in the present case, is controlled by the external circuit. In the unstable region, the energy-loss rate observed under clean vacuum conditions is found to agree approximately with the calculated growth rate of the kink mode.

High-$\beta$ confinement of a hot-ion plasma has been observed in the 2XII magnetic mirror experiment. The maximum measured $\beta$ values of 0.3 to 0.4 were near the limit predicted for mirror equilibrium in the 2XII mirror ratio of 1.8 to 2.3.

Analysis of the scattered intensity and photocount correlation function of light scattered from charged R17 virus indicates incipient macromolecular ordering.

Chemisorption of oxygen on Al and Mg was found to cause photon emission with a probability of about ${10}^{-7\mathrm{}}$ per molecule. The photon intensity was continuously recorded for oxygen exposures ${10}^{-8\mathrm{}}$-${10}^{-1\mathrm{}}$ Torr sec. The intensity is closely related to the chemisorption rate and a rate ${<10\mathrm{}}^{-3\mathrm{}}$ monolayer/sec was easily detected. Spectral analysis revealed broad emission bands with maxima at 5100 and 5900 Å for Al + ${\mathrm{O}}_2$ and at 4700 and 5600 Å for Mg + ${\mathrm{O}}_2$.

Measurements of the Kapitza conductance by the ac technique between 1.2 and 1.8 K are reported for thin oriented single-crystal disks of high-purity gallium. The data show convincing evidence that the conduction electrons play a dominant role in the transmission of heat across the metal-He-II interfaces.

An ellipsometer has been used with picosecond pulses to measure the time evolution of optically generated plasmas in intrinsic Ge. By measuring the change in optical ellipticity of a weak probe beam following the absorption of an intense excitation pulse, the time evolution of the plasma density can be determined with a precision of a few picoseconds. At a density of 1.7 × ${10}^{20}$ ${\mathrm{cm}}^{-3\mathrm{}}$, the ambipolar diffusivity of the plasma was observed to be a factor of 3 greater than the low-density value, consistent with a simple theoretical model of diffusion in the degenerate regime.

Ionization energies for chemisorbed acetylene, ethylene, and benzene exhibit $\pi$-orbital bonding shifts (∼ 0.9-1.5 eV) as well as large nonchemical-bonding relaxation shifts of ∼ 1-3 eV for both $\pi$ and $\sigma$ orbitals. Dehydrogenation of chemisorbed ethylene to acetylene for $T\gtrsim 230$°K is directly observed. We estimate $\pi -d$ bonding interaction strengths and chemisorption energies from spectroscopic energy levels and predict that this surface reaction becomes exothermic because of $\pi -d$ bonding.

It is shown that the long-ranged part of the dipolar interaction in ferromagnets leads to effective elastic and magnetoelastic constants for acoustic waves that depend on the polarization of the waves.

The joint probability distribution for $\mathrm{Re}G$ and $\mathrm{Im}G$ in a disordered one-dimensional system has been obtained by solving an integral equation numerically. Thus quantities directly related to transport properties have been obtained for the first time.

Double-quantum transitions have been observed in the resonance depolarization spectrum of ${}_{}{}^{12}{}_{}{}^{}\mathrm{B}$ implanted in a single-crystal beryllium host. The effect is observed at large depolarizing fields and gives a line unshifted by quadrupolar interactions.

Coincidence measurements of charged particles emitted in a narrow cone in ${}_{}{}^7{}_{}{}^{}\mathrm{L}\mathrm{i}+$${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$, near grazing incidence, show that the two-step breakup via the ${\frac{7}{2}}^{-}$ (4.63 MeV) state in the $\alpha +t$ channel is very weak, in agreement with the predictions of the corresponding inelastic process (${\sigma }_{\mathrm{tot}}=350\mathrm{}$ μb). An important $\alpha -d$ coincidence yield comes from the following mechanism: ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$(${}_{}{}^7{}_{}{}^{}\mathrm{Li}$, ${}_{}{}^6{}_{}{}^{}\mathrm{L}\mathrm{i}*$ (2.18 MeV)) ${}_{}{}^{198}{}_{}{}^{}\mathrm{Au}$, ${}_{}{}^6{}_{}{}^{}\mathrm{Li}_{}^{*}{}_{}{}^{}\left(2.18\mathrm{} \mathrm{MeV}\right)\to \alpha +d$; ${\sigma }_{\mathrm{tot}}<~9\pm 2$ mb. The experimental optimum $Q$ value of the first step of this process is $Q_{\mathrm{opt}}=-1.8\mathrm{}\pm 0.1$ MeV.

Thermal photons are present in every initial state, and nonthermal photons are present in many systems of interest. Furthermore, stimulated emission promotes the infrared divergence of quantum electrodynamics from logarithmic to an inverse power in a Planck distribution. I have calculated to order $e^2$ the background-photon corrections to the cross section for scattering a charged particle off an external Coulomb potential. I demonstrate the cancelation of infrared divergences, and derive a formal shift in the masses of charged particles. I interpret this shift, and discuss atomic spectra.

Asymptotically free field theories of the strong interactions make specific predictions for the breakdown of scaling in deep inelastic electroproduction. I propose to use the Bloom-Gilman local duality connection between inelastic structure functions and elastic form factors to predict the high-$q^2$ behavior of the magnetic form factor. The results agree with experiment but are not a conclusive test of asymptotic freedom.

The breakdown of Bjorken scaling in asymptotically free gauge theories of the strong interactions is explored for its implications on the large-$q^2$ behavior of nucleon form factors. Duality arguments of Bloom and Gilman are invoked to relate the form-factor behavior to the threshold properties of deep inelastic structure functions. For very large $q^2$ the form factors are predicted to fall faster than any inverse power of $q^2$.