Deformations of incompressible bodies with free boundaries

Communicated by C. Dafermos     

Poincaré series and holomorphic averaging

Summary We provide an alternate proof of McMullen's theorem on contractive properties of the Poincaré series operator in the special case of the universal covering. This case includes in particular Kra's Theta Conjecture.Oblatum 16-X-1991 & 14-IV-1992First author supported in part by a grant from the National Science Foundation     

The experimental structure of199Au and the interacting boson-fermion model

Gamma rays of¹⁹⁹Au obtained after double neutron capture in¹⁹⁷Au were measured at the ILL high flux reactor. A level scheme up to 1770 keV excitation energy is established. The result is compared with IBFM and Boson-Fermion-Symmetry calculations.     

Azine bridged silver coordination polymers: Powder X-ray diffraction route to crystal structure determination of silver benzotriazole

In continuation of our interest in solid-state structures of silver complexes of photographic importance, the structure for silver benzotriazole (AgBZT), has now been obtained. The preferred method for solving crystal structures is via single-crystal X-ray diffraction (XRD). However, for some materials, growing single crystals of appropriate size and quality is often difficult or even impossible. AgBZT is an example of such a silver complex with poor solubility. The usual routes to preparing single crystals using recrystallization from a cooperating solvent resulted in polycrystalline powder samples. We propose a crystal structure for AgBZT, solved from synchrotron X-ray powder diffraction data, using a direct-space Monte Carlo simulated annealing approach. AgBZT crystals are monoclinic, (P2₁/c), with unit cell dimensions, a=14.8052(3) Å, b=3.7498(4) Å, c=12.3495(12) Å, and β=114.200(6)°. The AgBZT complex is constructed from all three of the Benzotriazole (BZT) nitrogens bonding to a separate silver atom. As a consequence of this bonding mode, the structure is a highly cross-linked, coordination polymer.     

A note on an SOR-like method for augmented systems

Golub et al. (2001, BIT, 41, 71–85) gave a generalizedsuccessive over-relaxation method for the augmented systems.In this paper, the connection between the SOR-like method andthe preconditioned conjugate gradient (PCG) method for the augmentedsystems is investigated. It is shown that the PCG method isat least as accurate (fast) as the SOR-like method. Numericalexamples demonstrate that the PCG method is much faster thanthe SOR-like method.     

Self-organization in aggregating colloids

Summary The interceluster organization of a two-dimensional colloidal system undergoing diffusion-limited cluster-cluster aggregation is considered. During this process the system evolves into a stationary, scaling state. In this state the organization arises from effective intercluster repulsion due to the mutually exclusive depletion zones surrounding each cluster. It is shown that in the scaling regime the relevant size of the depletion zones is determined by the separation between clusters, rather than the cluster size. Paper presented at the I International Conference on Scaling Concepts and Complex Fluids, Copanello, Italy, July 4–8, 1994.     

InAs/GaSb/AlSb resonant tunneling spin device concepts

We discuss device concepts for creating spin-polarized current sources without external magnetic fields, using non-magnetic 6.1 Å semiconductor resonant tunneling structures. Spin filters, spin pumps, and spin transistors that exploit structural and bulk inversion asymmetries will be examined.