Materials Literature
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The precise assignments of cross polarization/magic angle spinning (CP/MAS) (13)C NMR spectra of cellulose I(alpha) and I(beta) were performed by using (13)C labeled cellulose biosynthesized by Acetobacter xylinum (A. xylinum) ATCC10245 strain from culture medium containing D-[1,3-(13)C]glycerol or D-[2-(13)C]glucose…
We theoretically study the development of spontaneous magnetization in diluted magnetic semiconductors as arising from a percolation of bound magnetic polarons. Within the framework of a generalized percolation theory we derive analytic expressions for the Curie temperature and the magnetization in the limit of low ca…
Understanding factors that affect the potassium (K) status of soil is important to chemical prediction of plant-available K in corn (Zea mays L.). Soils vary widely in their ability to replenish labile K from nonlabile forms. No research has been done to investigate the effects clay fraction mineralogy of South Dakota…
This paper presents piezoelectricity in germanium-doped silica (germanosilicate) films produced by poling treatment. The germanosilicate films were prepared on Si substrates by RF magnetron sputtering. The films were poled by electric fields of 2–4 ×10 7 V/m at a temperature above 300°C. Before the poling, no piezoele…
The electrical response of defect centres, which are distributed randomly in space and interact via electrostatic forces, is examined by Monte Carlo simulation of dipolar lattice gas models. Coulomb interactions are found to have a profound influence on the a.c. conductivity or the dielectric loss spectrum, when the i…
This paper describes a method of simultaneously executing both observations using a charge-coupled device (CCD) camera with stroboscopic light and measurement of bubble radius with light scattering. This optical system consists of a beam splitter inserted between a lens and the CCD camera, and a photomultiplier tube (…
The ultrasonic decomposition of a mixture of two hydrophilic organic compounds, phenol and p -chlorophenol, in aqueous solution was investigated. The effect of the initial concentration of phenol and p -chlorophenol on the overall decomposition rate was examined experimentally. The overall decomposition rate constant…
Abstract High molecular weight, soluble, amorphous, partially aliphatic polyimides were successfully synthesized using an ester acid high‐temperature solution imidization route, which allows one to control desired glass‐transition ( T g ) and processing temperatures. This method involves the prereaction of aromatic di…
We study geometrically controlled twist transitions of a nematic confined between a sinusoidal grating and a flat substrate. In these cells, the transition to the twisted state is driven by surface effects. We have identified the mechanisms responsible for the transition analytically and used exact numerical calculati…
[structure: see text] New chiral terpyridines containing Frechét-type dendrons have been readily synthesized by coupling dendritic benzyl bromide and 4'-[6-(2,2'-dihydroxy-1,1'-binaphthyl)]-2,2':6'2' '-terpyridine. These chiral dendritic terpyridines were used to efficiently construct high molecular weight hybrid meta…
Two new biflavonoids, namely, 6'"-hydroxylophirone B (1) and 6'"-hydroxylophirone B 4"'-O-beta-glucoside (2), were isolated from the stem bark of Ochna integerrima, together with five known compounds. The structures of 1 and 2 were determined by spectral data interpretation.
An original interferometer-based setup for measurements of length of needlelike samples is developed, and thermal expansion of o-TaS(3) crystals is studied. Below the Peierls transition the temperature hysteresis of length L is observed, the width of the hysteresis loop deltaL/L being up to 5 x 10(-5). The behavior of…
The purpose of this study is to clarify experimentally the influence of streaming induced by ultrasonic vibration on heat transfer using a horn-type ultrasonic vibrator. A horn tip of 6 mm diameter and 60.7 kHz resonant frequency was used as the ultrasonic transducer. Heat transfer experiments for a downward-facing ho…
The dynamic mean-field density functional method, driven from the generalized time-dependent Ginzburg–Landau equation, was applied to the mesoscopic dynamics of the multi-arms star block copolymer melts in two-dimensional lattice model. The implicit Gaussian density functional expression of a multi-arms star block cop…
Abstract Novel alternating conjugated copolymers ( P1–P6 ) consisting of an electron‐deficient benzothiadiazole and a variety of electron‐rich thiophene‐arene‐thiophene units were synthesized by palladium‐catalyzed polycondensations (Stille and Suzuki reactions), aiming at processable materials with a reduced optical…
A hypothetical protein encoded by the gene YjeE of Haemophilus influenzae was selected as part of a structural genomics project for X-ray analysis to assist with the functional assignment. The protein is considered essential to bacteria because the gene is present in virtually all bacterial genomes but not in those of…
We study the structural and dynamical characteristics of the sodium atoms inside and outside the ``diffusion channels'' in glassy ${\mathrm{Na}}_{2}\mathrm{O}\ensuremath{-}4{\mathrm{SiO}}_{2}$ (NS4) using classical molecular dynamics. We show that on average neither energetic arguments nor local environment considerat…
The supercooled dynamics of a Lennard-Jones model liquid is numerically investigated studying relevant points of the potential energy surface, i.e., the minima of the square gradient of total potential energy V. The main findings are (i) the number of negative curvatures n of these sampled points appears to extrapolat…
The surface tension of interacting polymers in a good solvent is calculated theoretically and by computer simulations for a planar wall geometry and for the insertion of a single colloidal hard sphere. This is achieved for the planar wall and for the larger spheres by an adsorption method, and for smaller spheres by a…
The N-confused porphyrin complex Mn(II)(NCHPP)Br exhibits a nonplanar porphyrin ring with an inner core C-H on the inverted pyrrole ring. The aerobic metal oxidation promotes the dissociation of an inner-core proton on the inverted pyrrole ring and changes the N-confused porphyrin conformation to a planar porphyrin ri…