The integral stable allocation problem on graphs

As a generalisation of the stable matching problem Baïou and Balinski (2002) [1] defined the stable allocation problem for bipartite graphs, where both the edges and the vertices may have capacities. They constructed a so-called inductive algorithm, that always finds a stable allocation in strongly polynomial time. Here, we generalise their algorithm for non-bipartite graphs with integral capacities. We show that the algorithm does not remain polynomial, although we also present a scaling technique that makes the algorithm weakly polynomial.     

A mainly NMR-based structure elucidation of a surprising vindoline trimer with the aid of non-uniform sampled 1H-13C HSQC and HMBC spectra

Structural Chemistry - Two unexpected and unusual vindoline trimers, a ketone and a methyl ether cation, were isolated from a reaction aimed at producing new, synthetically modified vinca...     

Thermal properties of electrospun polyvinylpyrrolidone/titanium tetraisopropoxide composite nanofibers

Journal of Thermal Analysis and Calorimetry - In this work, polyvinylpyrrolidone/titanium tetraisopropoxide (PVP/TTIP) composite nanofibers were prepared by electrospinning from alcoholic...     

Rapid Optimization of Reaction Conditions Based on Comprehensive Reaction Analysis Using a Continuous Flow Microwave Reactor

Generally, the flow method has the advantage of a precise control over the reaction parameters and a facile modification of the reaction conditions, while a continuous flow microwave reactor allows for the quick optimization of reaction conditions owing to the rapid uniform heating. In this study, we developed a “9+4+1 method” to optimize reaction conditions based on comprehensive reaction analysis using a flow microwave reactor. The proposed method is expected to contribute to the synthesis of various fine and bulk chemicals by reducing cost and wastage, and by conserving time.     

Pyridino-18-crown-6 ether type chemosensors containing a benzothiazole fluorophore unit: Synthesis and enantiomeric recognition studies

Three new fluorescent enantiopure pyridino-18-crown-6 ethers containing a benzothiazole unit were prepared, and the enantiomeric discrimination of these sensor molecules toward the hydrogen perchlorate salts of 1-phenylethylamine, 1-(1-naphthyl)ethylamine, phenylglycine methyl ester and phenylalanine methyl ester was studied in acetonitrile by fluorescence spectroscopy. The ligands revealed appreciable or moderate selectivity toward the enantiomers of hydrogen perchlorate salts of 1-phenylethylamine, 1-(1-naphthyl)ethylamine and phenylglycine methyl ester.     

Brane vector phenomenology

Local oscillations of the brane world are manifested as massive vector fields. Their coupling to the Standard Model can be obtained using the method of nonlinear realizations of the spontaneously broken higher-dimensional space–time symmetries, and to an extent, are model independent. Phenomenological limits on these vector field parameters are obtained using LEP collider data and dark matter constraints.     

Electronic states at dislocations and metal silicide precipitates in?crystalline silicon and their role in?solar cell materials

Predominant dislocation types in solar silicon are dissociated into 30°- and 90°-partials with reconstructed cores. Besides shallow 1D-band localized in their strain field and a quasi-2D band at the stacking fault connecting the two partials, the existence of several intrinsic core defects with deep lying levels has been demonstrated by electron spin resonance. The majority of core defects occur in nonequilibrium situations and, with the exception of a small EPR-signal assigned to a reconstruction defect, vanish after careful annealing above 800°C. There is good evidence now that part of deep levels observed in dislocated silicon is associated with impurities, especially with transition metal impurities. Electron-hole-pair recombination at a dislocation mainly runs via its shallow bands and is strongly increased by impurities bound to its core or in the strain field. The concentration of these impurities can be reduced by gettering processes to such a low level that radiative recombination at dislocations yields a luminescence efficiency of 0.1% at room temperature. A quite coherent picture has emerged for metal impurity precipitation in silicon. Early stages of precipitation in defect-free silicon are characterised by kinetically selected metastable defects forming as a result of large chemical driving forces for precipitation. Such defects are associated with deep level spectra which show the properties of extended multielectron defects. The evolution of the system to energetically more favourable configurations proceeds via ordinary particle coarsening but also via internal ripening, a process reminiscent of the above-mentioned metastable defects. Electronically, the defects evolve into metal-like inclusions which in general seem to act as strong recombination centers for minority carriers. In the presence of dislocations metastable defects quickly transform into equilibrium structures in the course of precipitation or do not form at all. In the presence of several metal impurities silicide precipitates which can be described as solid solutions of the respective metal atoms are observed, which is at least qualitatively in accord with ternary phase diagrams. Like single-metal silicide precipitates, strong minority carrier recombination is also typical for those multi-metal silicide particles.     

Spatial frequency combs and supercontinuum generation in one-dimensional photonic lattices

We experimentally demonstrate the formation of spatial supercontinuum and of spatial frequency combs in nonlinear photonic lattices. This process results from multiple four-wave mixing initiated by launching two Floquet-Bloch modes into a one-dimensional lattice. The dynamics of the waves is sensitively dependent on the transverse momentum difference between the two initial modes: when this momentum difference is commensurable with the lattice momentum the waves evolve into a frequency comb, whereas when it is incommensurable the waves evolve into a supercontinuum of spatial frequencies.     

Higher-band gap soliton formation in defocusing photonic lattices

We report on the experimental observation of higher-band gap solitons in a one-dimensional photonic lattice possessing a defocusing saturable nonlinearity. Pure Floquet-Bloch modes of the first three bands are excited using a prism-coupler setup, and spatial gap solitons of different width are formed, the latter property being related to the increasing anomalous diffraction in the three bands and the fixed value of the nonlinearity in our lithium niobate sample.     

Dendronized Polymers via Macromonomer Route in Supercritical Carbon Dioxide

Radical polymerizations from third to fifth generation macromonomers were conducted in supercritical carbon dioxide (scCO₂). It was found that all monomers were not soluble in such a medium, and reactions occurred in the CO₂‐swollen monomer matrices. Despite the expected severe diffusion limitations, very high conversions and molecular weights were obtained. It is believed that the plasticization effect induced by the CO₂ plays a key role in these surprising findings. Scanning force microscopical analyses confirmed that mainly linear dendronized polymers were obtained and therefore chain transfer to polymer is virtually irrelevant.