Materials Literature
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We propose a novel type of ionization front in layered semiconductor structures. The propagation is due to the interplay of band-to-band tunneling and impact ionization. Our numerical simulations show that the front can be triggered when an extremely sharp voltage ramp ($\sim 10 {\rm kV/ns}$) is applied in reverse dir…
Abstract With increasing awareness of environmental concerns, various chemical finishes for processing of textiles have been discussed. In this paper major changes which have occured to satisfy the consumer's demand in terms of comfort, easy care, health, and hygiene are reviewed. © 2002 Wiley Periodicals, Inc. J Appl…
We describe a Monte Carlo scheme for simulating polydisperse fluids within the grand canonical ensemble. Given some polydisperse attribute $σ$, the state of the system is described by a density distribution $ρ(σ)$ whose form is controlled by the imposed chemical potential distribution $μ(σ)$. We detail how histogram e…
We study thermopower in strongly correlated electron systems with orbital degeneracy using numerical diagonalization method on finite-size clusters. It is shown that the thermopower is strongly enhanced by the spin and orbital degrees of freedom, but the resistivity is significantly less affected. A key for the strate…
This review covers the research on brown algal pheromones from the first structural characterisation of an active principle in 1971 to the recent detailed insight into their biosynthesis. Development of analytical methods and bioassays that lead to the identification of a structural variety of different fatty acid-der…
Large spectral fluctuations, on a time scale of many seconds, are demonstrated in the surface-enhanced Raman scattering of single rhodamine 6G molecules adsorbed on silver nanocrystals and excited at 532 nm. These fluctuations are especially evident in the case of the vibrational bands at 614 and 774 cm -1 . A definit…
In this work the complete valence-band structure of the molybdenum dichalcogenides ${\mathrm{MoS}}_{2},$ ${\mathrm{MoSe}}_{2},$ and $\ensuremath{\alpha}\ensuremath{-}{\mathrm{MoTe}}_{2}$ is presented and discussed in comparison. The valence bands have been studied using both angle-resolved photoelectron spectroscopy (…
The growth of vertically aligned carbon nanotubes using a direct current plasma enhanced chemical vapor deposition system is reported. The growth properties are studied as a function of the Ni catalyst layer thickness, bias voltage, deposition temperature, C2H2:NH3 ratio, and pressure. It was found that the diameter,…
Two-dimensional lattices of carbon, boron-nitride, and fluorine-carbon compositions are treated with ab initio methods in order to evaluate and compare their mechanical properties in a uniform fashion. The demonstrated robustness of continuum elasticity up to very small length-scale allows one to define and compute th…
Several proteases require propeptides for the correct folding of their own protease domain. We have recently found that the propeptide from a thermostable subtilisin homolog aqualysin I can refold subtilisin BPN' when added in trans. Here, we constructed chimeric genes with subtilisin E and aqualysin I to attempt the…
Abstract Biosynthetic processes for production of linear proteins, polysaccharides, and polyhydroxyalkanoates (PHAs) are discussed. Processes for converting the linear biopolymers into useful products are described. Techniques and additives for improving the processability of PHAs and potential applications of PHAs ar…
Abstract A series of poly(arylene ether)s were successfully prepared by aromatic, nucleophilic substitution reactions with various perfluoroalkyl‐activated bisfluoromonomers with 4,4′‐bishydroxybiphenyl and 4,4′‐bishydroxyterphenyl. 4,4′‐Bishydroxyterphenyl was synthesized through the Grignard coupling reaction of mag…
Poly(lactic acid) (PLA) is a biodegradable polymer, but its applications are limited by its high cost. Blending granular starch with PLA reduces the cost, but the blend has poor strength properties. In this study, a 55/45 (w/w) mixture of PLA (weight-average molecular weight = 120,000 Da) and dried wheat starch was bl…
A previously unexplored class of heterocyclic bidentate chelating groups, 6-carboxamido-5,4-hydroxypyrimidinones (6-substituted-HOPYs), have been synthesized by two routes that provide a flexible entry into this ligand system. These are related to, but distinct from, the hydroxypyridonates and have been characterized…
Thermoplastic elastomers of a styrene−butadiene−styrene (SBS) triblock copolymer containing grafts of an azobenzene side-chain liquid crystalline polymer were prepared by polymerization of an azobenzene acrylate monomer in solutions with dissolved SBS. Stretching thin films at room temperature induces long-range orien…
Two new porphyrin arrays-a hexamer and a nonamer-have been synthesized and characterized by elemental analysis as well as mass, (1)H NMR, and UV-vis spectroscopic methods. The scheme of construction of these arrays employs a synthetic protocol involving sequential "organic" and "inorganic" reactions conducted, respect…
The lamello-columnar mesophase of a [1]benzothieno[3,2-b][1]benzothiophene-2,7-dicarboxylate (BTBT) derivative has been investigated by means of X-rays on an aligned sample. The most probable model of molecular organisation corresponds to an assembly of microcolumns made of alternatively crossed molecules, within the…
The aluminum chloride complexes [(O∼∼O)AlCl] 2, I, [(O∼CHMe∼O)AlCl] 2, II, and TPPAlCl, III, where O∼∼O = 5,5‘,6,6‘-tetramethyl-3,3‘-di- tert -butyl-1,1‘-biphenoxide, O∼CHMe∼O = 2,2‘-ethylidenebis-4,6-di- tert -butylphenoxide, and TPP = tetraphenyl porphyrin, are shown to be inactive in initiating the ring-opening pol…
The nuclear and magnetic structures of the monoclinic ( P 2 1 / n, A-LFP) and rhombohedral ( R 3̄ B-LFP) forms of Li 3 Fe 2 (PO 4 ) 3 have been solved by using powder neutron diffraction at room temperature and 1.5 K on polycrystalline samples. Both structures are built on [Fe 2 (PO 4 ) 3 ] ‘lantern units' that are co…
The crystallization of ordered microporous−mesoporous silica, SBA-15, has been investigated in the presence of an ionic salt, such as sodium chloride, under microwave-hydrothermal conditions. The crystallization was performed by templating a silica precursor (tetraethyl orthosilicate or sodium silicate) with pluronic1…