Materials Literature
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Bone morphogenetic proteins (BMPs) were originally identified by their ability to induce ectopic bone formation and have been shown to promote both chondrogenesis and chondrocyte hypertrophy. BMPs have recently been found to activate a membrane serine/threonine kinase signaling mechanism in a variety of cell types, bu…
We have investigated fast relaxational processes and the much debated boson peak in the strong glass former, ${\mathrm{B}}_{2}{\mathrm{O}}_{3},$ from 60 to 1300 K (glass transition temperature 523 K) using coherent inelastic neutron scattering. The wave-vector dependence of the dynamic structure factor is different fo…
The room-temperature photoluminescence (PL) of Tb3+ ions has been studied. The Tb ions were implanted into 200 nm thick SiO2 on Si wafers. To achieve a uniform Tb distribution, the implantations were performed at 50, 100, and 190 keV to a total dose of 8.8×1014–1.3×1016 ions/cm2, resulting in Tb concentrations of 0.18…
Erbium environments in several multicomponent glasses are investigated using X-ray absorption fine structure spectroscopy on the Er LIII-edge. Glass hosts studied include aluminosilicate, fluorosilicate, phosphosilicate, alkali phosphate, fluoride, and another multicomponent silicate glass. The Er–O separation is foun…
Milled B-doped mesophase pitch-based carbon fibers (mMPCF's) prepared from a melt-blown petroleum mesophase pitch precursor material have been developed for enhanced Li uptake capacity in Li ion batteries. Raman spectroscopy has been used to investigate the structure of graphitized and B-doped mMPCF's using 632.8-nm H…
A variety of 18-membered cyclodepsipeptides with alternating repeats of aromatic (phenyl or pyridyl) and Ser units in the ring have been synthesized and studied by X-ray crystallography for self-assembly patterns. Single-crystal structures of the macrocycles showed similar, relatively flat-ring structures. Those molec…
A homogeneous and stable amorphous‐type cordierite (2MgO2Al 2 O 3 5SiO 2 ) powder was prepared by a solution‐polymerization route employing a Pechini resin or a poly(vinyl alcohol) (PVA) solution as the polymeric carrier. After calcination at 800°C for 1 h under atmospheric conditions, the bulky precursor changed into…
EXAFS spectra of distorted and disordered small MoS 2 particles were simulated by means of the FEFF7 program. The simulated EXAFS spectra of several models were compared with observed EXAFS spectra of small MoS 2 particles which had been characterized by TEM (Calais et al. J. Catal . 1998, 174, 130). The EXAFS spectra…
Heterologous expression of the phaC1 gene from Pseudomonas aeruginosa, which encodes one of the polyhydroxyalkanoic acid synthases, in Escherichia coli impaired in fatty acid beta-oxidation results in polyhydroxyalkanoic acid accumulation when cells were cultivated on fatty acids. We evaluated the application of the f…
Excitation of a triad artificial photosynthetic reaction center consisting of a porphyrin (P) covalently linked to a fullerene electron acceptor (C 60 ) and a carotenoid secondary donor (C) leads to the formation of a long-lived C • + −P−C 60 • - charge-separated state via photoinduced electron transfer. This reaction…
A scheme for generating complex, spatially separated patterns of multiple types of semiconducting and/or metallic nanocrystals is presented. The process is based on lithographic patterning of organic monolayers that contain a photolabile protection group and are covalently bound to SiO2 surfaces. The process results i…
High-quality B-doped homoepitaxial diamond films have been synthesized by microwave plasma chemical-vapor-deposition (CVD) using a mixture consisting of CH 4 , H 2 , and trimethylboron B(CH 3 ) 3 diluted by H 2 gas. These films have been obtained on the basis of the approach that high-quality diamond films should be g…
The photochemistry of M3(CO)12 [M = Ru (1a), Os (1b)] with pyrazole, 3,5-dimethylpyrazole, and 3,5-diphenylpyrazole is documented. With 1a, photolysis with pyrazole leads to the substitution product HRu3(CO)10(C3H3N2) (2a). In the case of 1b, the initial product is the ortho-metallated species HOs3(CO)10(C3H3N2) (3b),…
Dans ce travail on presente une vision generale des techniques numeriques permettant une augmentation importante du rapport signal-bruit dans une grande variete d'applications comme, par exemple, dans les mesures par sonde de Langmuir destinees a la determination des fonctions de distribution de l'energie des electron…
Numerous circular, 30 to 270 μm‐diameter bore holes in several species of gastropod and bivalve shells from Julian Lake, southern Ontario, Canada are similar in appearance to the ichnotaxa Oichnus simplex, Oichnus paraboloides, and Tremichnus isp. These ichnotaxa are well described from marine systems but are rarely r…
X-ray photoemission measurements of CuSO4 are presented.
The crystal structures of five new cristobalite-related sodium aluminosilicates with four different structure types from the system Na 2− x Al 2− x Si x O 4 , 0 ≤ x ≤ 1 [Na 1.95 Al 1.95 Si 0.05 O 4 , P 4 1 2 1 2, a = 5.2997 (6), c = 7.0758 (9) Å; Na 1.75 Al 1.75 Si 0.25 O 4 , Pbca , a = 10.4221 (11), b = 14.264 (3), c…
Mechanical properties of materials are based on structure or morphology and on the micromechanical processes of deformation and fracture, i.e. on the “micromechanics”. Developments mainly in electron microscopy and scanning force microscopy opened up a wide range of experiments previously impossible, including the in…
An experimental method has been developed that uses laser-induced fluorescence detection of N atoms to monitor NO formation from a surface-catalyzed reaction on quartz. Well-characterized mixtures of N and O atoms were generated through NO titration of N atoms produced in a microwave discharge. Experiments were carrie…
A type 329Jl duplex stainless steel was gas tungsten arc welded without filler material in an Ar–N 2 gas mixture atmosphere with the aim of changing only the nitrogen content in the weld metal. The effect of nitrogen on the microstructure and corrosion properties of the weld metal was examined. An increase in nitrogen…