Materials Literature
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It is indicated that the stability of average valence +4/3 of Cu, i.e. Cu +4/3 , in various (DCNQI) 2 Cu salts is the consequence of strong correlation at Cu sites. It is also discussed that the phase diagram separating metallic and insulating states together with the reentrance on the plane of pressure and temperatur…
Prolonged exposure to band-gap light decreases the photoconductivity of annealed films of amorphous chalcogenides (${\mathrm{As}}_{2}$${\mathrm{S}}_{3}$, ${\mathrm{As}}_{3}$${\mathrm{S}}_{7}$, AsS, ${\mathrm{As}}_{2}$${\mathrm{Se}}_{3}$, ${\mathrm{GeS}}_{2}$, ${\mathrm{GeSe}}_{2}$, and GeSe). This can be attributed to…
The thermal expansion, specific heat, dielectric constant, and resistivity of the novel organic nonlinear crystal, L-arginine phosphate monohydrate have been measured as a function of temperature. The thermal expansion is highly anisotropic and has been interpreted on the basis of crystal structure. The dielectric con…
SF6 samples (PSF6=100 or 200 kPa) were submitted to point-to-plane dc negative polarity corona discharges in the presence of water [concentration=2000 ppmv (parts per million by volume)] or without the addition of water. The stable gaseous byproducts formed, (SO2F2, SOF2, and S2F10) were assayed by gas-phase chromatog…
Abstract An investigation was carried out into the effect of the extent of reaction on the mechanical properties, in a mixture of an epoxy prepolymer and a cycloaliphatic diamine, above the gel point. First, the most adequate technique to approach the extent of reaction was chosen between differential scanning calorim…
The in-crystal molecular dipole moment of the nonlinear optical material 2-methyl-4-nitroaniline has been determined from a charge density analysis of x-ray diffraction data. The results indicate a considerable enhancement of the free molecule dipole moment, due to the crystal field. The analysis suggests that aspheri…
Collagen fibrils generated in vitro at 37 degrees C by enzymic removal of C-terminal propeptides from type I pC-collagen (an intermediate in the normal processing of type I procollagen to collagen containing the C-terminal propeptides but not the N-terminal propeptides) display shape polarity, with one tip fine tapere…
Hall effect and infrared absorption measurements of n-type silicon carbide of the 6H polytype are employed to investigate the energy position of the ground state and excited states of the nitrogen donor. A donor model is proposed that assigns four series of absorption lines to electronic transitions of three donor spe…
Hot-filament chemical vapor deposition is a common method employed for diamond deposition. Due to the filament-substrate proximity, large temperature variations across the substrate is often possible. Variations in substrate temperature need to be minimized in order to deposit polycrystalline diamond films of uniform…
Stoichiometric films of cupric and cuprous oxide are deposited on Si, MgO, and Y-ZrO2 substrates by pulsed excimer laser ablation technique. It is found that the equilibrium phase diagram based considerations dictate the phase formation. The films are characterized by small-angle x-ray diffraction, infrared, and UV-vi…
The electronic structure of ${\mathrm{La}}_{\mathit{x}}$${\mathrm{Sr}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{TiO}}_{3}$ has been studied by photoemission and x-ray absorption spectroscopy. Electron doping through La substitution induces a new photoemission feature of Ti 3d character within the band gap of ${\…
We investigate the second-order nonlinear optical properties of octupolar molecules, as opposed to traditional charge transfer dipolar molecules. We consider in particular the case of hexasubstituted aromatic rings, trianiline, trinitrobenzene, and tri-amino-,tri-nitro-benzene (TATB).
Bond formation fundamentals. Composition and characteristics of adhesives. Composition and characteristics of wood. Characteristics conferred in preparation of wood. Characteristics conferred in preparing adhesives. Wood geometry factors. Consolidation processes. Quality control. Bond performance: testing and evaluati…
A study of the semiconductor-metal transition in the series ${\mathrm{La}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Sr}}_{\mathit{x}}$${\mathrm{CoO}}_{3}$, x=0.0--0.4, using electron-spectroscopy techniques is presented. The results show that the ground state of ${\mathrm{LaCoO}}_{3}$ has strongly mixed characte…
The zinc-blende (ZB) and wurtzite (W) structures are the most common crystal forms of binary octet semiconductors. In this work we have developed a simple scaling that systematizes the T=0 energy difference \ensuremath{\Delta}${\mathit{E}}_{\mathrm{W}\mathrm{\ensuremath{-}}\mathrm{ZB}}$ between W and ZB for all simple…
Effects on diamond-diamond friction of ultra-high vacuum (UHV) ( approximately 4*10 -9 Torr) and low pressure ( approximately 1*10 -5 Torr) gases including hydrogen, oxygen and nitrogen in their molecular and atomic states have been investigated. The friction coefficient for diamond sliding on diamond in UHV was found…
Using site-specific mutagenesis, we have constructed two mutants of Escherichia coli dihydrofolate reductase (ecDHFR) to investigate further the function of a weakly acidic side chain at position 27 in substrate protonation: Asp27-->Glu (D27E) and Asp27-->Cys (D27C). The crystal structure of D27E ecDHFR in a binary co…
The gene (pcaB) for 3-carboxymuconate lactonizing enzyme (CMLE; 3-carboxymuconate cycloisomerase; EC 5.5.1.2) from Pseudomonas putida has been cloned into pMG27NS, a temperature-sensitive expression vector, and expressed in Escherichia coli N4830. The specific activity and kinetic parameters of the recombinant CMLE we…
The effect of pressure on the Raman and IR modes of NaOH and NaOD have been measured for pressures up to 25 GPa and temperatures down to 100 K, using the diamond anvil technique. Changes in the Raman and IR spectra indicate transformations into different structures. The results reveal that the phase diagrams of NaOH a…
The initial sticking probability of copper on a thin silica film has been measured in the temperature range 90–700 K using temperature programmed desorption. The copper sticking probability depends markedly on the surface temperature, varying from 0.6±0.1 at 90 K to less than 0.1 above 400 K. Upon covering the silica…