Materials Literature
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We investigate photoisomerization (PI), the shape change of a molecule upon photoabsorption, in a dissipative environment using a simple spin-boson model. We identify two classes of environment depending on whether it "entangles" with the molecule. In the absence of entanglement, the environment merely causes a blue s…
Using photoconduction study we demonstrate that the low-temperature Ohmic conduction of TaS$_3$ is not provided by single-particle excitations -- electrons and holes excited over the Peierls gap. Instead, the low-temperature Ohmic conduction is mostly provided by collective excitations having the activation energy abo…
Abstract The focus of this work is the study of the dispersion mechanism of soybean stock‐based nanofibers in a plastic matrix. The cellulose nanofibers were extracted from soybean stock by chemo‐mechanical treatments. These are bundles of cellulose nanofibers with a diameter ranging between 50 and 100 nm and lengths…
A simple supramolecular hydrogel based on D-glucosamine, a naturally occurring aminosaccharide, promises new biomaterials for applications such as wound healing.
We show how nacre and pearl construction in bivalve and gastropod molluscs can be understood in terms of successive processes of controlled self-assembly from the molecular- to the macro-scale. This dynamics involves the physics of the formation of both solid and liquid crystals and of membranes and fluids to produce…
A simple two-step plasmachemical methodology is outlined for the fabrication of microcondensor surfaces. This comprises the creation of a superhydrophobic background followed by pulsed plasma deposition of a hydrophilic polymer array. Microcondensation efficiency has been explored in terms of the chemical nature of th…
Vapor deposition has been used to create glassy materials with extraordinary thermodynamic and kinetic stability and high density. For glasses prepared from indomethacin or 1,3-bis-(1-naphthyl)-5-(2-naphthyl)benzene, stability is optimized when deposition occurs on substrates at a temperature of 50 K below the convent…
In this letter, we report that vertically well-aligned ZnO nanowires were grown on GaN epilayers and c-plane sapphire via a vapor-liquid-solid process by introducing a 3 nm Au thin film as a catalyst. In our experiments, epitaxially grown ZnO nanowires on Au-coated GaN were vertically well-aligned, while nanowires nor…
The Langmuir−Blodgett (LB) method was applied to low molecular weight organogelator N -[ N -(6-hydroxyhexyl)-3-carbamoylpropyl]-3,4,5-tris(dodecyloxy)benzamide ( 1 ) to form molecular-assembly fibers on a solid substrate. Molecule 1 formed a stable monolayer up to 40 mN/m at the air−water interface. The monolayer was…
We model an entire poly(ethylene terephthalate) (PET) solid-state polymerization (SSP) process with precrystallizers, crystallizers, SSP reactors, and dryers using a unified cell approach. This approach builds complex unit-operation models using individual cells, or continuous-stirred-tank reactor (CSTR) models. Each…
We propose a new method for fitting a model of specimen charging to scanning electron microscope (SEM) images. Charging effects cause errors when one attempts to infer the size or shape of a specimen from an image. The goal of our method is to enable image analysis algorithms for measurement, segmentation, and three-d…
Shells of the freshwater, pulmonate snail Physa (Mollusca, Gasteropoda), ranging from 0.5 to 10 mm in length, were studied using scanning microscopy, x-ray analysis, and infrared spectroscopy. Results obtained suggest that the shell is composed of aragonite, which occurs in several distinct crystalline forms. A select…
A spectrum image is recorded as an x-y array of beam locations at each of which a spectrum of radiation is recorded as stimulated by the beam. The large database or "datacube" that results from a single image presents a significant challenge to the analyst to recover information efficiently, especially in the case whe…
Cu(PPh3)3(TCNE) (TCNE = tetracyanoethylene) and 14 other examples form [TCNE]22- dimers possessing a long 2.89 +/- 0.05 A two-electron four-center (2e-/4c) C-C bond in the solid state. This bond arises from the overlap of the b2g pi* singly occupied molecular orbital (SOMO) on each [TCNE]*- fragment, forming a filled…
The p25 protein from Thermus aquaticus (Taq) was initially identified as a protein that bound preferentially to AT-rich DNA. The purified protein was characterized as a homodimer. In vitro, this protein displays nonsequence specific dsDNA-binding activity.1 Database searches revealed more than 30 gram-positive bacteri…
Three practically useful reductions of phenomenological mesoscopic field dislocation mechanics (PMFDM) are explored to evaluate some of their capabilities and limitations. Lower-order gradient plasticity arises as one of these reduced frameworks, and a boundary condition appropriate for the modelling of constrained pl…
The compounds p-R−C 6 H 4 −CH CH−C⋮C−TMS (R = NO 2, N(CH 3 ) 2, OCH 3 ) were obtained from Wittig olefination of TMS−C⋮C−CH 2 PPh 3 Br with p-R−C 6 H 4 −CHO in THF, which can be desilylated to give p-R−C 6 H 4 −CH CH−C⋮C−H. Treatment of RuHCl(CO)(PPh 3 ) 3 with p-R−C 6 H 4 −CH CH−C⋮C−H produced RuCl(CO)(PPh 3 ) 2 (CH…
Patterned polymer films are grafted from chemically active surface templates prepared by the localized electrochemical oxidation of an n-octadecyltrichlorosilane monolayer to form addressable areas for the site-selective binding of a bromine-terminated precursor. Atom-transfer radical polymerization of polystyrene gen…
We present strategies for improving the power output of large-area pn-junctions for thermoelectric power conversion. The gradient of the pn-junction's built-in potential is used to separate thermally generated electron–hole pairs. An externally applied temperature gradient along the pn-junction induces a driving force…
Weltrekord: Die Isolierung und Charakterisierung eines dianionischen homoleptischen Isocyanidmetallats gelang erstmals mit [Fe(CNXyl)4]2− (Xyl=2,6-Dimethylphenyl; siehe Struktur: Fe rot, N blau, C grau). Spektroskopie- und Strukturdaten sprechen dafür, dass in dieser elektronenreichen Spezies die stärkste Metall-Isocy…