Convergence of bivariate cardinal interpolation

We give necessary and sufficient conditions for the convergence of cardinal interpolation with bivariate box splines as the degree tends to infinity.     

Positive definiteness and positive differences

A previous inequality [2] in certain context, which holds in the application to the monotonicity of correlations in classical discrete Heisenberg ferromagnets with 2-dimensional spin [3], is extended to positive definiteness of a function on a group.     

The thermal degradation of acrylic acid–ethylene polymers

A Study of the thermal degradation of a copolymer of ethylene and acrylic acid is presented. The degradation mechanism of the acrylic acid portion of the polymer was found to be dehydration of the acid, forming anhydride, and decarboxylation of the anhydride, forming unsaturation. The resultant unsaturation reduces the copolymer-s stability to both thermal and oxidative degradation.     

Dielektrische Eigenschaften von Benzin-in-Wasser-Mikroemulsionen im Frequenz-bereich 100 kHz bis 5 MHz

Ohne Zusammenfassung     

A general integrated process for synthesizing olefin oxides

Metal oxide solid reactants are shown to react with vicinal alkyl dibromides to selectively form olefin oxides and fully regenerable metal bromides.     

Sound attenuation study on the bose-Einstein condensation of magnons in TlCuCl3

We investigate experimentally and theoretically sound attenuation in the quantum spin system TlCuCl3 in magnetic fields at low temperatures. Near the point of Bose-Einstein condensation of magnons a sharp peak in the sound attenuation is observed. The peak demonstrates a hysteresis as a function of the magnetic field pointing to a first-order contribution to the transition. The sound damping has a Drude-like form arising as a result of hard-core magnon-magnon collisions. The strength of the coupling between lattice and magnons is estimated from the experimental data. The puzzling relationship between the transition temperature and the concentration of magnons is explained by their "relativistic" dispersion.     

Simulations and Sensitivity Analysis of the Vestibulo-Ocular Reflex

Computer simulations and sensitivity analysis of vestibulo-ocular reflex (VOR) gain and phase were performed. The analyses were used to identify neural structures and anatomic sites capable of producing abnormal VOR gain and phase behaviors reported to exist in blind adults.     

Theory of digital phase shifters based on high-Tcsuperconducting films

A theory of digital phase shifters based on transition from a superconducting (S) state into a normal (N) state in high-T_c superconductor (HTS) films is developed. It is shown that the insertion-loss level in the phase shifters is determined by the commutation quality of the HTS film and does not depend on the S-N switching element shape and size. The procedure for designing the S-N phase shifter with minimum insertion loss is equivalent to designing a matching circuit for the termination Z=√R_SR_N (R_S and R_N are the resistances of the switching element in the S- and N-states, respectively). Different versions of S-N phase shifters are suggested and discussed. High-quality S-N phase shifters can be successfully designed in a 1-10 GHz frequency range and find application on the receiving end of microwave systems     

Spin relaxation in nanowires by hyperfine coupling

Hyperfine interactions establish limits on spin dynamics and relaxation rates in ensembles of semiconductor quantum dots. It is the confinement of electrons which determines nonzero hyperfine coupling and leads to the spin relaxation. As a result, in nanowires one would expect the vanishing of this effect due to extended electron states. However, even for relatively clean wires, disorder plays a crucial role and makes electron localization sufficient to cause spin relaxation on the time scale of the order of 10 ns. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)