Nonequilibrium desorption of atoms and molecules from surfaces

A model, based on concepts from the theory of atom-surface accommodation coefficients, for nonequilibrium desorption of atoms and molecules from surfaces is proposed. We contend that the nonequilibrium effects should be expected to be general properties of not only polyatomic molecule-surface systems, but of all desorbing systems. The model predicts large deviations from the equilibrium dependences, on desorption angle, of (a) the desorbing atomic flux, (b) the average energy of desorbing atoms and (c) the desorbing atomic speed ratio. The deviations are larger when the accommodation coefficient is smaller.     

Vibrational,rotational, and isotopic dependence of CaBr X2Σ spin-rotational and HFS parameters

The previously published molecular-beam, laser-rf, double-resonance study of the rotational and isotopic dependences of the spin-rotational and hyperfine interactions in the v″ = 0, X²Σ state of CaBr is supplemented here with data for v″ = 1. The vibrational dependence of the parameters is now obtained. The results for CaBr are displayed along with analogous, previously published results for CaF and CaCl.     

Landau-Ginzburg theory of phase transitions in heated rotating nuclei

The Landau-Ginzburg theory is applied to heated rotating superfluid systems. It is demonstrated that the free energy F' is an even function of the order parameter Δ even when external fields are present. The energy surfaces F'(Δ) are calculated for various rotational frequencies and temperatures. These surfaces provide clear illustrations of first-order and second-order phase transitions, as well as a critical point.     

Whittaker vectors and conical vectors

A holomorphic family of differential operators of infinite order is constructed that transforms conical vectors for principal series representations of quasi-split, linear, semi-simple Lie groups into Whittaker vectors. Using this transform, it is shown that algebraic Whittaker vectors (as studied by Kostant) extend to ultradistributions of Gevrey type on principal series representations. For each element of the small Weyl group, a meromorphic family of Whittaker vectors is constructed from this transform and the Kunze-Stein intertwining integrals. An explict formula is derived for the smooth Whittaker vector (discovered by Jacquet), in terms of these families of ultradistribution Whittaker vectors. In particular, this gives new proofs of Jacquet's analytic continuation of the smooth Whittaker vector and its functional equation (Jacquet and Schiffman). Applications of the transform are also given to the theory of Verma modules.     

Bestimmung der Kernmomente des Ho165 aus der Hyperfeinstruktur des Grundzustandes im Ho I-Spektrum

In an atomic beam magnetic resonance experiment, the hyperfine interaction constantsA andB of the⁴ I _2/15-groundstate of Ho¹⁶⁵ were found to beA=800,58389 (50) MHz,B=?1667,997 (50) MHz. Using an effective value for 〈r ^?3〉, the magnetic moment of the Ho¹⁶⁵ nucleus was calculated to beμ=4·1(4)μ _n . The quadrupolement was determined by use of the 〈r ^?3〉 given byWatson andFreeman. The result isQ=2·4·10^?24 cm².     

Synthesis of thia-ellipticine, 5,11-dimethylbenzothieno[2,3-g]isoquinoline

1,4-Dimethyldibenzothiophene (VII) was synthesized and was converted with butyl dichloromethyl ether to the 2-aldehyde (VIII). The structure was confirmed by an independent synthesis of the 2-ester (XI) derived from it. The 2-aldehyde (VIII) with aminoacetaldehyde diethylacetal formed the Schiff′s base (IX), and Pomeranz-Fritsch cyclization with 105% superphosphoric acid then formed thia-ellipticine (II), an isostere of the antitumor alkaloid, ellipticine.     

Experiments on damping at contacts of a sphere with flat plates

An apparatus for studying slip damping at rounded contacts for three different systems of forces is described. Experimental results for the constant normal force/varying tangential force problem when a Type 316 stainless-steel sphere is driven between two flat Type 316 stainless-steel plates are presented. They are in fair agreement with theoretical predictions by R. D. Mindlin,et al.