Growth, thermal stability and structure of ultrathin Zn-layers on Pd(1 1 1)

Low-energy ion scattering with monolayer sensitivity was applied to investigate ultrathin films of zinc on Pd(1?1?1). Uptake curves taken at 150?K indicate the simultaneous growth of multilayers with negligible interlayer transport. Annealing experiments for two-monolayer films reveal a rapid decrease in the zinc content on the surface layer at temperatures above 300?K, forming a metastable state with a Pd:Zn surface ratio of approx. 1:1 in the temperature region between 400 and 550?K. This state is most easily explained as a slightly buckled p(2?×?1)-PdZn surface alloy, with Zn atoms located approx. 0.25?? above their Pd counterparts.     

On data-guided optimal control simulation of human motion

This work investigates the combination of optical motion capturing data with optimal control simulations of human motion, which can be important in a wide range of applications in the professional as well as the private sector, ranging from health and ergonomics over human-machine-interaction to sports and games [1–3]. There are methodically very different approaches to include optical measurement data in the simulation of human motion, see e.g. [4–6]. Two different approaches to combine data and simulation are investigated in this work. Either we use a soft constraints approach, where the difference of simulated and measured marker positions is part of the objective function (1), or we formulate an hard constraints approach with nonlinear constraints that set an upper bound on this difference (2), while the objective function is purely physiologically motivated. (© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

New Organosiloxanes Containing Silacycles

Abstract

The synthesis of carbon substituted 1, 1-dichloro- and l, l-bis(diethylamino)silacyclobutanes and butenes and their polycondensation reactions with bisphenol A, 1,2-ethanediol and 1,6-hexanediol is described. The monomer silacycles and the organosiloxane polymers are characterized by NMR (¹H-, ¹³C-, ²⁹Si-), GPC, DSC and elemental analysis.     

On vibrations in non-linear,forced, friction-excited systems

To accelerate the development of non-linear, friction-excited systems, i.e. automotive friction brakes, novel test procedures are being developed. These include the study of the system's forced vibrations. However, there is a lack of knowledge concerning feasible test procedures, the assessment of the gathered data, and the possible vibration phenomena. In this context, the contribution at hand discusses vibrations in non-linear, forced, friction-excited systems. In the pre-flutter regime proposed criteria for identification of parameter regions in which limit cycle oscillations can occur are challenged. In the post-flutter regime frequency spectra for different excitation conditions are studied. (© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Controlling the early stages of pentacene growth by supersonic molecular beam deposition

The key role of the pentacene kinetic energy (Ek) in the early stages of growth on SiOx/Si is demonstrated: islands with smooth borders and increased coalescence differ remarkably from fractal-like thermal growth. Increasing Ek to 6.4 eV, the morphology evolves towards higher density of smaller islands. At higher coverage, coalescence grows with Ek up to a much more uniform, less defected monolayer. The growth, interpreted by the diffusion mediated model, shows the critical nucleus changing from 3 to 2 pentacene for Ek>5-6 eV. Optimal conditions to produce single crystalline films are envisaged.     

New q‐Hermite polynomials: characterization,operators algebra and associated coherent states

This paper addresses a construction of new q‐Hermite polynomials with a full characterization of their main properties and corresponding raising and lowering operator algebra. The three‐term recursive relation as well as the second‐order differential equation obeyed by these new polynomials are explicitly derived. Relevant operator actions, including the eigenvalue problem of the deformed oscillator and the self‐adjointness of the related position and momentum operators, are investigated and analyzed. The associated coherent states are constructed and discussed with an explicit resolution of the induced moment problem. The phase collapse in a q‐deformed boson system is studied.     

Packing of three copies of a graph

A graph of order n is said to be 3-placeable if there are three edge-disjoint copies of this graph in K_n. An (n, n − 1)-graph is a graph of order n with n − 1 edges. In this paper we characterize all the (n, n − 1)-graphs which contain no cycles of length 3 or 4 and which are 3-placeable. © 1996 John Wiley & Sons, Inc.