The Influence of Multi-Photon Absorption on Photon Statistics

A previous approximation scheme [6] which allowed to calculate, in a simple manner, the quantity Δn²/n (n mean value and Δn² variance of the photon number) in the course of a multi-photon absorption process, is extended to study the change of the shape of the photon distribution, too. It turns out that there is a tendency to symmetrize the distribution. Moreover, an approximative expression for the asymptotic distribution to which the distribution tends after a sufficiently strong absorption, irrespective of the initial distribution, is found in form of a Gaussian.     

Styrofoam calorimeter for high energy CO2 lasers

A simple calorimeter that has been used to measure pulse energy and energy distribution of a pulsed gas-dynamic laser is described. The pulses had an energy density 10 J cm^-2 and width 0.1 s. Energy is determined from the volume of styrofoam melted by the pulse. Results showing the linearity of the method are given.     

Numerical evaluation of the 1S12-state radiative level shift

The one-photon self-energy radiative level shift for an electron in a Coulomb potential is evaluated numerically for the $\text{1S}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ state. The evaluation is done for values of the nuclear charge Z = 10, 20,…, 110. The errors in the values obtained are estimated to be less than 0.1 %. The results are compared with the results of previous calculations. The evaluation is based on the expressions given in the preceding paper.     

Zur Bestimmung der kritischen Micellbildungskonzentration von Polyäthylenoxiden durch pH-Wert-Messung

Colloid and Polymer Science - Die kritische Mizellbildungskonzentration von Polyäthylenoxiden wurde durch pH-Wert-Messungen bestimmt. Die Ergebnisse wurden mit der Bildung eines...     

A micro-reactor for preparing uniform molecularly imprinted polymer beads

In this study, uniform spherical molecularly imprinted polymer beads were prepared via controlled suspension polymerization in a spiral-shaped microchannel using mineral oil and perfluorocarbon liquid as continuous phases. Monodisperse droplets containing the monomers, template, initiator, and porogenic solvent were introduced into the microchannel, and particles of uniform size were produced by subsequent UV polymerization, quickly and without wasting polymer materials. The droplet/particle size was varied by changing the flow conditions in the microfluidic device. The diameter of the resulting products typically had a coefficient of variation (CV) below 2%. The specific binding sites that were created during the imprinting process were analysed via radioligand binding analysis. The molecularly imprinted microspheres produced in the liquid perfluorocarbon continuous phase had a higher binding capacity compared with the particles produced in the mineral oil continuous phase, though it should be noted that the aim of this study was not to optimize or maximize imprinting performance, but rather to demonstrate broad applicability and compatibility with known MIP production methods. The successful imprinting against a model compound using two very different continuous phases (one requiring a surfactant to stabilize the droplets the other not) demonstrates the generality of this current simple approach.     

Functional liquid crystal films selectively recognize amine vapours and simultaneously change their colour

During recent years, cholesteric liquid crystals have found only a few applications, one of them being temperature detection; in this study, however, we intend to show that the combination of cholesteric liquid crystals and molecules with a trifluoroacetyl function can be applied to optically detect amine vapours.     

Long cycles and spanning subgraphs of locally maximal 1-planar graphs

A graph is 1-planar if it has a drawing in the plane such that each edge is crossed at most once by another edge. Moreover, if this drawing has the additional property that for each crossing of two edges the end vertices of these edges induce a complete subgraph, then the graph is locally maximal 1-planar. For a 3-connected locally maximal 1-planar graph G, we show the existence of a spanning 3-connected planar subgraph and prove that G is Hamiltonian if G has at most three 3-vertex-cuts, and that G is traceable if G has at most four 3-vertex-cuts. Moreover, infinitely many nontraceable 5-connected 1-planar graphs are presented.