Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
Five active site residues, Thr11, Glu12, Lys15, Lys37, and Ser41, implicated by the protein crystal structure studies of Escherichia coli DTBS, were mutated to determine their function in catalysis and substrate binding. Nine mutant enzymes, T11V, E12A, E12D, K15Q, K37L, K37Q, K37R, S41A, and S41C, were overproduced i…
By combining vibrational spectra and ab initio calculations, we obtained a consistent description of the IR and nonresonant Raman spectra, including intensities, of four thiophene based polymers—undoped and heavily doped poly(thiophene) (PTh), undoped poly(thieno[3,4-b]benzene) (PITN), and poly(thieno[3,4-b]pyrazine)…
Density functional calculations are used to investigate the non-ferroelectric end-points of the KTN and PZT alloy systems and to address the errors in the local approximation for KNbO3. In PbZrO3, substantial hybridization is found between O 2p and Zr 4d states and between O 2p and Pb s and p states. A strong Γ point…
The reduction of rhodium(III) porphyrins in polar aprotic solvents is a two-electron irreversible reaction yielding directly the Rh(I) complex. The cause of this irreversibility is not the metal−metal dimerization of the initially formed Rh(II) complex as believed earlier but rather deligation which generates a second…
The compound ${\mathrm{La}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$${\mathrm{Sr}}_{\mathrm{x}}$${\mathrm{MnO}}_{3}$ undergoes structural and magnetic phase transitions as a function of temperature and pressure. The temperature at which the structural phase transition from a high-temperature rhombohedral phase to a low-t…
Thiophenolate-capped nanoclusters of cadmium sulfide and the cadmium thiophenolate compounds Cd(SPh) 2, [Cd(SPh) 4 ](Me 4 N) 2, [Cd 4 (SPh) 10 ](Me 4 N) 2, and [Cd 4 X 4 (SPh) 6 ](Et 4 N) 2 (X = Cl, Br, I) have been studied by low-frequency FT-IR and Raman spectroscopy. In the spectrum of the cluster [S 4 Cd 10 (SPh)…
Chemical modification of isotactic polypropylene via a free-radical mechanism was studied using an on-line electron spin resonance spectrometer. Peroxides were used to provide primary radicals upon thermal decomposition at elevated temperatures for the generation of polymer backbone radicals. Four types of peroxides,…
It has been long thought that microscopic mechanisms related to magnetic short-range order were responsible for the temperature dependence of the electron paramagnetic resonance g tensor in low-dimensional magnetic systems. We show here that the demagnetizing field can explain qualitatively and quantitatively the obse…
Statistical model discrimination methods have been applied to the modeling of copolymerization kinetics in order to improve our ability to correctly choose between competing models. The objectives were to quantify the benefits of using model discrimination methods, to examine available copolymer measurements, and to r…
We consider the Hubbard model for electrons in a two-dimensional quasiperiodic tiling using the Hartree-Fock approximation. Numerical solutions are obtained for the first three square approximants of the perfect octagonal tiling. At half-filling, the magnetic state is antiferromagnetic. We calculate the distributions…
Organic single-crystal thin films (2−10 μm thick) of 1-(phenylazo)-2-naphthol (Sudan I) were grown by capillary filling from its molten state (∼133 °C) into cells constructed of two parallel pieces of indium tin oxide (ITO) coated glass followed by slow cooling to room temperature. The solidified crystals were needle-…
Fully dense silicon nitride (Si 3 N 4 ) has been produced by hot isostatically pressing α‐Si 3 N 4 powder at 1740°C under 160 MPa, with 0.5 wt% Y 2 O 3 and 0.5 wt% Al 2 O 3 as sintering additives. The sintered material was composed of very fine (0.5 μm) and equiaxed grains, as required for superplasticity. Before defo…
The oscillatory behavior of single crystalline n-Si(111) in dilute ammonium and sodium fluoride solutions is investigated. Simultaneous in-situ Fourier transform infrared analyses performed in the multiple internal reflection (FTIR-MIR) mode and photocurrent measurements show a pronounced variation in the integrated S…
ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTCP/MAS 13C NMR Spectra of Frozen Solutions of Poly(vinyl alcohol) with Different TacticitiesFumitaka Horii, Kenji Masuda, and Hironori KajiView Author Information Institute for Chemical Research, Kyoto University, Uji, Kyoto 611, Ja…
Adducts of the zwitterionic (ZW) form of merocyanine (MC) of five photochromic spirooxazines (SO) and spiropyrans (SP) have, for the first time, been prepared photochemically or thermally through a trapping reaction of metastable MC with trimethylsilyl cyanide (TMSCN) in dichloromethane. The adducts (ZWAs) form easily…
The chemical nature, especially with respect to the surface, of carbon blacks obtained by pyrolysis of used tyres (CBP) is very important for their use as reinforcing filler in rubbers. Both SIMS and Raman spectroscopy were used to investigate the surface and bulk chemistry of CBP obtained by vacuum pyrolysis of used…
The self-assembling of the [Ni(NO2)2(en)2], Mn(II), and NO2- constituents affords the bimetallic chain compound MnNi(NO2)4(en)2. The Mn(II)−Ni(II) intrachain interaction is ferromagnetic, and the compound is a metamagnet with a critical field 1.2 kOe. The magnetic properties were interpreted quantitatively, using a cl…
Dynamic mechanical experiments were conducted on melt-extruded uniaxially oriented high- density polyethylene films having a well-defined stacked lamellar morphology. Samples were cut at different angles with respect to the original machine direction (MD) and tested by increasing the temperature from 20 to 130 °C at a…
The aim of this experimental investigation was to compare the effect of using autologous particulate bone grafts with and without a bioresorbable barrier covering for augmentation of the rabbit skull bone. For this purpose, bilateral, circular, 8 mm wide and 1 mm deep skull bone defects were prepared and overfilled wi…
A series of combined main chain−side group thermotropic polyesters having varying lengths of oxypolymethyleneoxy spacers between the aromatic polyester main chain and the side azobenzene mesogenic unit have been synthesized and their liquid crystalline properties have been investigated. The thermal and liquid crystall…