Materials Literature
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The polyvinylchloride (PVC) differs from other polymer materials by low thermostability. The process of dehydrochlorination takes place even at low temperatures. The purpose of this investigation was to determine the influence of different PVC additives on formation of hydrogen chloride (HCl) from thermal degradation…
We study the transport of electrons in a Fibonacci magnetic superlattice produced on a two-dimensional electron gas modulated by parallel magnetic-field stripes arranged in a Fibonacci sequence. Both the transmission coefficient and conductance exhibit self similarity and the six-circle property. The presence of exten…
The crystallographic superstructures of the charge-orbital ordered phases were investigated for layered manganites, ${\mathrm{Nd}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{1+x}{\mathrm{MnO}}_{4}$ $(x=2/3,$ 3/4), by high-resolution electron microscopy (HREM) at low temperature. Transverse and sinusoidal structural distortion g…
Monomer−dimer equilibrium of nitroso compounds was investigated in the solid state under cryogenic photochemical conditions. It was found that nitroso dimers can be UV-photolytically converted to nitroso monomers at 12 K, and reverted to dimers by visible light irradiation or warming above 170 K. Such a photothermal “…
Porphyrins bearing two external coordination sites allowed the stepwise preparation of polymetallic oligomers connected by metal centers.
Kinetic studies were performed with microperoxidase-8 (Fe(III)MP-8), the proteolytic breakdown product of horse heart cytochrome c containing an octapeptide linked to an iron protoporphyrin IX. Mn(III) was substituted for Fe(III) in Mn(III)MP-8. The mechanism of formation of the reactive metal-oxo and metal-hydroperox…
The solvent structure in the crystals of ten aspartic proteinases has been analyzed to find the possible roles of conserved water molecules in their structure and activity. 17 waters have been identified which are common to at least eight of the ten examined enzyme structures. These include the catalytic water molecul…
A versatile and simple method for preparing highly homogeneous iron-oxide-doped alumina nanosized powders of different compositions is described. The method consists of the hydrolysis with ammonium hydroxide of aluminum and iron nitrate aqueous solutions confined within the reverse micelle nanocavities of water-in-oil…
The crystal structure of the YrbI protein from Haemophilus influenzae (HI1679) was determined at a 1.67-A resolution. The function of the protein had not been assigned previously, and it is annotated as hypothetical in sequence databases. The protein exhibits the alpha/beta-hydrolase fold (also termed the Rossmann fol…
A method is presented to calculate efficiently small-angle neutron and X-ray solution scattering intensities from explicit-atom models of macromolecules and the surrounding solvent. The method is based on a multipole expansion of the scattering amplitude. It is particularly appropriate for extensive configurational av…
The magnetic susceptibility of the organic superconductors $\ensuremath{\kappa}\ensuremath{-}(\mathrm{h}8\mathrm{}or\mathrm{}\mathrm{d}8\ensuremath{-}\mathrm{E}\mathrm{T}{)}_{2}X,$ $X=\mathrm{Cu}(\mathrm{NCS}{)}_{2}$ and $\mathrm{Cu}[\mathrm{N}(\mathrm{CN}{)}_{2}]\mathrm{Br}$ has been studied. A metallic phase below $…
The chemical reaction of a hydrogenated diamond surface with the radical initiator benzoyl peroxide was performed in order to investigate the reactivity of the diamond surface. It was found that the hydrogen atoms on the diamond surface are abstracted by the radical species generated from benzoyl peroxide. The reactio…
The T<sub>g</sub> of thin films of PS with sec-butyl-initiated proton terminations and those with the lower energy fluoroalkylsilyl termination was measured. In comparison, the latter exhibit a drastically higher reduction in the T<sub>g</sub> with decreasing film thickness. The result evidences the first time that a…
Abstract The use of natural rubber (NR) for partly substituting elastomeric chlorinated polyethylene (CPE) was determined. Mechanical and thermal aging properties as well as oil resistance of the blends were also investigated. The amount of NR in blends significantly affected the properties of the blends. The blends w…
Results of a powder neutron diffraction study of the high-temperature monoclinic ${(F}_{M}^{\mathrm{HT}})$ to a low-temperature monoclinic ${(F}_{M}^{\mathrm{LT}})$ phase transition in $\mathrm{Pb}({\mathrm{Ti}}_{1\ensuremath{-}x}{\mathrm{Zr}}_{x}){\mathrm{O}}_{3}$ discovered recently by Ragini et al. are presented fo…
Dihydroazulene (DHA)/vinylheptafulvene (VHF) photochromism has been investigated by studying the isomerization of 1,2,3,8a,9-pentahydrocyclopent[a]azulene-9,9-dicarbonitrile through complete active space-self consistent field calculations on the ground (S(0)) and first excited (S(1)) states of smaller model compounds.…
Locally rubbing the surface of a polymer using the stylus of an atomic force microscope (AFM nano-rubbing) has recently found extensive applications in prototyping novel micro- and nano-structured liquid crystal (LC) electro-optic devices. We report here on the detailed characteristics of the AFM nano-rubbed polyimide…
Recently we have found that carbons can be grown into well-aligned two-dimensional sheets (dubbed carbon nanowalls) on a substrate through manipulating the electrical conduction from the catalyst to the bias electrode in a microwave plasma enhanced chemical vapor deposition system. The existence of a strong lateral el…
The gas-phase derivatization procedure was employed for direct (i.e., without chemical activation of terminal carboxylic groups) amidization of oxidized single-walled carbon nanotubes (SWNTs) with simple aliphatic amines. The procedure includes treatment of SWNTs with amine vapors under reduced pressure and a temperat…
Carbon nanotubes yield to mechanical force by a primary dislocation dipole whose formation energy describes the thermodynamic stability of the tubule. However, the real-time strength is determined by the rate of defect formation, defined in turn by the activation barrier for the bond flip. First extensive computations…