Materials Literature
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We investigate freezing characteristics of a finite dipolar hexagonal plate by the Monte Carlo simulation. The hexagonal plate is cut out from a piled triangular lattice of three layers with FCC-like (ABCABC) stacking structure. In the present study an annealing simulation is performed for the dipolar plate uniaxially…
Information about the nature of the low-temperature anomalies and in particular the properties of the tunneling systems in silica and lithium silica glasses are revealed via computer simulations. The potential energy landscape of these systems is systematically explored for adjacent pairs of local minima which may act…
The n-alkanes C12H26, C14H30, and C16H34 have been imbibed and solidified in mesoporous Vycor glass with a mean pore diameter of 10 nm. The samples have been investigated by x-ray diffractometry and calorimetric measurements. The structures and phase sequences have been determined. Apart from a reduction and the hyste…
We present a general multi-component density functional theory in which electrons and nuclei are treated completely quantum mechanically, without the use of a Born-Oppenheimer approximation. The two fundamental quantities in terms of which our theory is formulated are the nuclear N-body density and the electron densit…
A mean-field approximation of a model for double perovskites that takes into account the coupling between itinerant electron spins and localized spins is developed. As in previously reported theoretical results, and contrary to experimental observation, the critical temperature is suppressed for large electron density…
Using stimulus-sensitive microgel particles as an emulsifier, we have prepared a new type of emulsion responsive to pH, ionic strength, and temperature changes. Each of these environmental changes can trigger a volume phase transition in poly( N -isopropylacrylamide) (PNIPAM) microgel particles containing some carboxy…
Very high molecular weight ( M n up to 700 000) and narrowly polydispersed (PDI = 1.1−1.4) hyperbranched polyglycerols (HPG) were synthesized by ring-opening multibranching polymerization of glycidol using dioxane as an emulsifying agent. Broader molecular weight distributions with low molecular weight fractions were…
Abstract Summary: Uniform core‐sheath nanofibers are prepared by electrospinning a water‐in‐oil emulsion in which the aqueous phase consists of a poly(ethylene oxide) (PEO) solution in water and the oily phase is a chloroform solution of an amphiphilic poly(ethylene glycol)‐poly( L ‐lactic acid) (PEG‐PLA) diblock copo…
Pendry et al. have reported electromagnetically anisotropic and inhomogeneous shells that, in theory, completely shield an interior structure of arbitrary size from electromagnetic fields without perturbing the external fields. Neither the coordinate transformation-based analytical formulation nor the supporting ray-t…
Singlet oxygen reacts with binaphthyl phosphine derivatives such as 1,1'-binaphthyl di-tert-butyl phosphine to form the corresponding binaphthyl-2-oxide phosphine oxides. This new intramolecular arene epoxidation reaction proceeds with complete retention of stereochemistry. The binaphthyl-2-oxide di-tert-butyl phosphi…
A novel algorithm to track the columnar front in one- (1D) and two-dimensional (2D) solidification problems has been developed and coupled with the governing equations of a deterministic model to predict the columnar-to-equiaxed transition (CET). The new algorithm, inspired by the cellular automaton (CA) technique, re…
The intensities of Raman-scattering bands in the spectrum of vitreous As 2 S 3 assigned to vibrations of intrinsic homopolar As-As ( ∼ 234 cm −1 ) and S-S ( ∼ 490 cm −1 ) bonds increase much more with the power of the exciting laser than does the principle vibrational band which is related to As-S-As glass-network vib…
A novel differential interferometer is being developed to measure the electron density gradient and its fluctuations. Two separate laser beams with slight spatial offset and frequency difference are coupled into a single mixer making a heterodyne measurement of the phase difference which is <1% of the total pha…
The Saupe ordering matrix of a banana-shaped mesogenic molecule as a solute in a common nematic calamitic solvent has been determined by 2H-NMR spectroscopy as a function of temperature. The temperature dependence of the Saupe ordering matrix element associated with the principal molecular axis is consistent with a gl…
Adsorption and reaction of benzene molecules on clean ${\mathrm{TiO}}_{2}(110)$ and on ${\mathrm{TiO}}_{2}(110)$ with deposited Pd nanoparticles are investigated using a combination of scanning tunneling microscopy (STM), temperature-programmed desorption, and first-principles calculations. Above $\ensuremath{\sim}50\…
Atom-transfer radical polymerization (ATRP) has been used to modify the surface of ZnO nanowires with a variety of methacrylate and styrene polymers in a living fashion. The polymers show narrow polydispersities ( M n / M w = 1.10−1.19), and polymerization could be reinitiated after removal of the nanowires from solut…
YciF is a protein that is up-regulated when bacteria experience stress conditions, and is highly conserved in a range of bacterial species. YciF has no known structure or biochemical function. To learn more about its potential molecular function and its role in the bacterial stress response, we solved the crystal stru…
Licht an: Ganz im Gegensatz zu SnIV-Komplexen normaler Porphyrine binden SnIV-Komplexe von N-invertierten Oxoporphyrinen Halogenide stark und unter deutlicher Fluoreszenzverstärkung in der axialen Position (siehe Schema; Ar=Ph, p-CF3C6H4, p-CH3C6H4) und können somit als neuartiger Prototyp von Fluoreszenzsensoren für…
Kristallkugeln: Kolloidale Kristallmikropartikel mit der Struktur eines dreidimensionalen photonischen Kristalls können mit einem Tröpfchengenerator erzeugt werden. Ihre Reflexionsspektren lassen sich als codierende Elemente verwenden, und ein Multiplex-Bioassay bestätigt die Eignung der Partikel als Codierungsträger…
Optimizing the active site: A pyridoxal 5′-phosphate(PLP)-dependent alanine racemase was converted into a retro-aldolase by a single active-site mutation. This new catalyst reacts efficiently with quaternary β-hydroxy α-amino acids, a class of molecules that natural aldolases have not been evolved to handle. Computati…