Materials Literature
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Using a recently developed method, we show here that solvent effects on the first molecular hyperpolarizabilities of push-pull polyenes can be predicted by evaluation of the relaxation contribution βr to the hyperpolarizability from vibrational infrared and Raman intensities and vibrational frequencies. The molecules…
In 1990, Liu and Cohen presented a pseudopotential study of the structural and electronic properties of β- C 3 N 4 , a hypothetical compound. The calculated properties of β- C 3 N 4 , including bulk modulus and velocity of sound, were found to be comparable to that of diamond suggesting high values for hardness and fo…
We present an analysis of the extensive photolysis of an adsorbate resulting from adsorbate core-level excitation. The system studied was SiF4 adsorbed on Ge(100) at 30 K. Photolysis fragments and molecular species (identified with Si 2p soft x-ray photoemission spectroscopy) were measured as a function of monochromat…
The hydrothermal synthesis and single-crystal structure of potassium vanadium(V) selenite, K(VO 2 ) 3 (SeO 3 ) 2 , are reported. K(VO 2 ) 3 (SeO 3 ) 2 is a layered phase based on a hexagonal tungsten-oxide-like array of corner-sharing VO 6 octahedra capped by Se atoms, and is isostructural with NH 4 (VO 2 ) 3 (SeO 3 )…
Hydrogenophaga pseudoflava (formerly Pseudomonas pseudoflava) was able to accumulate a large amount of copolyesters when grown on mixed substrates of glucose and lactones in a batch fermentation. Lactones such as γ-butyrolactone, γ-valerolactone, and higher analogues generally did not support cell growth when used as…
Cyclic oligo(3-hydroxybutyrate), oligo(3-HB), was synthesized and purified, resulting in oligolides that contained three to seven (R)-3-hydroxybutyrate units (triolides up to heptolides). In addition, linear 3-HB octamers obtained as either tert-butyl or methyl esters were substituted with different end groups at the…
The vacancy model for the electronic structure in silicon of substitutional transition elements near the end of the 3d, 4d, and 5d series is described and a simplified theoretical treatment for their paramagnetic properties is presented. It is concluded that the complete set of such impurities for which experimental i…
The increasing commercial importance of polyhydroxyalkanoates calls for the development of new, more efficient production processes. This can only be achieved by considering the kinetics of polyhydroxyalkanoate accumulation in fermentors, but efforts in this area have been few. In a 10-L fed-batch fermentor, Alcaligen…
SrS:Ce is an intensively investigated phosphor due to its blue-green electroluminescence, which shows efficient blue emission after filtering. Recently reported devices based on this material have demonstrated a luminous efficiency of 1.6 lm/W. The luminescence properties of SrS:Ce,X (X=Na or Cl) have been studied on…
Spherical quantum-dot--quantum-well nanocrystallites, with internal radial quantum-well band profiles, can now be fabricated. Pair states in these nanoheterostructures are determined by electron-hole attraction, global confinement in the dot, and local confinement within the well. Configuration-interaction calculation…
Interrelationship among electronic structures of α -(ET) 2 I 3 , (ET) 2 MHg(SCN) 4 and κ -(ET) 2 X is studied theoretically. The effects of on-site Coulomb interaction are investigated at absolute zero within the Hartree-Fock approximation. If Coulomb interaction exceeds some critical value, various kinds of antiferro…
Microstructural changes that occur in a GeSbTe film during repetitious overwriting in phase-change optical recording were investigated. The GeSbTe active layer was melted by a focused laser diode (LD) beam during each overwriting process over amorphous mark formation. The repetitious solidification and liquefaction pr…
The miscibility, morphology, and biodegradability of a binary blend of bacterial poly((R)-3-hydroxybutyric acid)(P((R)-3HB);Mn = 300,000) with atactic poly((R,S)-lactic acid)(P((R,S)-LA);Mn = 9,000) were studied by means of differential scanning calorimetry, optical microscopy, scanning electron microscopy, and hydrol…
X-ray diffraction and electrical resistance have been measured for amorphous and crystalline Te 1- x Se x mixtures (0≤ x ≤1) under high pressure up to 30 GPa, and four high pressure phases of Te-Se mixtures have been observed: a monoclinic phase with 6 atoms per unit cell (M-I phase); a monoclinic phase with 4 atoms p…
A number of Escherichia coli strains including K12, B, W, XL1-Blue, DH5 alpha, HB101, JM109, and C600 were transformed with the stable high-copy-number plasmid pSYL105 containing the Alcaligenes eutrophus polyhydroxyalkanoic acid biosynthesis genes, and were subsequently compared for their ability to synthesize and ac…
Based on first-principles total-energy calculations we have determined the chemical identity and adsorption site of the adatoms observed recently in scanning tunneling microscopy on the SiC(0001)\ensuremath{\surd}3\ifmmode\times\else\texttimes\fi{}\ensuremath{\surd}3 surface. The calculations indicate that Si adatoms…
Pseudomonas cepacia was evaluated for its ability to utilize xylose, a major hemicellulosic sugar of hardwoods, for the production of the biodegradable, thermoplastic poly(β-hydroxybutyrate) (PHB). This culture produced 2.6 g∙L −1 of biomass containing 60% (w/w) PHB when grown in shake flasks on an ammonium-limited, m…
SrTiO3 thin film has been formed on Si(100) substrates with various single buffer layers such as SrO, CeO2, CaF2, CoSi2 and a multibuffer layer, YSZ/Y2O3/YBa2Cu3O7 by ArF excimer laser ablation. The relation of lattice orientation of buffer layers with SrTiO3 layer has been elucidated. The orientation of SrTiO3 film i…
It is increasingly clear that poly(3-hydroxybutyrate) (PHB) is not just an inert storage polymer, confined to certain bacteria, but a ubiquitous, interactive, solvating biopolymer involved in important physiological functions. Low molecular weight PHB, complexed to other macromolecules (c-PHB), is widely distributed i…
The poly(3-hydroxybutyrate) (PHB) depolymerase structural gene of Comamonas sp. (phaZCsp) was cloned in Escherichia coli and identified by halo formation on PHB-containing solid medium. The nucleotide sequence of a 1719 base pair MboI fragment was determined and contained one large open reading frame (ORF1, 1542 base…