A one-step synthesis of a free base secochlorin from a 2,3-dimethoxy porphyrin
The synthesis and X-ray structure of a C2 symmetric secochlorin 2, obtained by a photosensitized oxidative ring opening of a 2,3-dimethoxy porphyrin, is described.
Materials Literature
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Microstructural change and precipitation hardening in melt–spun Mg–X–Ca alloys
Mg–Al–Si–Ca and Mg–Zn–Ca base alloys were rapidly solidified bymelt spinning at the cooling rate of about a million K/s. The melt-spun ribbons were aged in the range 100–400%C for 1 h. The effect of additional elements on microstructural change and precipitation hardening after heat treatment was investigated using TE…
Thermochemical Properties of Si2F6 and SiF4 in Gas and Condensed Phases
The available data for determining the thermochemical parameters for Si2F6 and SiF4 has been assembled. With this information, the thermochemical functions for Si2F6 and SiF4 have been calculated as ideal gases in the harmonic oscillator approximation. These results are presented in the format of the NIST–JANAF Thermo…
Sigma radicals in gamma-irradiated single crystals of 2-thiothymine
Thioanalogs of the nucleic-acid bases are known photosensitive probes and good traps of radiation energy. Radiation-induced sulfur-centered free radicals stabilized on the base thioanalogs molecules are of the cationic origin. Their electronic configuration is of the π type, unless an electron-donating group, like Cl−…
Molecular dynamics study of deposition mechanism of cubic boron nitride
We have performed molecular dynamics simulations of bombardment of graphitic boron nitride (gBN) by energetic boron and nitrogen particles in order to examine the roles of ion bombardment in ion/plasma-assisted deposition of cubic boron nitride (cBN) thin films. We have found that the interaction of the energetic part…
Influence of Deformation Temperature on Microstructure Evolution and Static Recrystallization of Polycrystalline Copper
Static recrystallization was studied in warm and hot deformed polycrystalline copper (99.99%). Samples were compressed to a strain of 0.25 at 573 K and 723 K at a strain rate of 2×10−1 s−1, quenched in water, and subsequently isothermally annealed at 673 K . Static recrystallization kinetics were found to be faster in…
Sewing for the Apparel Industry
I. APPAREL PRODUCTION. 1. Overview to Apparel Production. 2. Industrial Equipment: Orientation. 3. Basic Machine Skills. 4. Basic Production Skills. 5. Other Industrial Machines. II. BASIC OPERATIONS. 6. Seams, Types, Classifications, and Basic Plain Seams. 7. More Plain Seams. 8. Seam Finishes. 9. Self-finished Seams…
Magnetic Properties of TbCu7-Type Sm-Fe-Co-Nb-Zr System Nitriding Compounds.
Experiments were carried out to investigate the magnetic properties of Sm-Fe-Co-Nb-Zr system nitriding compounds with TbCu7-type structure. Sm8(Fe0.95Co0.05)88.0Nb4.0-xZrx (X=0-4) alloy ribbons were prepared by the single roller rapid-quenching method, and the effects of alloy composition, and conditions of heat-treat…
A New Sealant Material for Solid Oxide Fuel Cells Using Glass-Ceramic.
We report a new sealant material for solid oxide fuel cells (SOFCs) using glass-ceramic. A glass-ceramic based on the CaO-Al2O3-SiO2 system was selected as a sealant because it can be easily molded to give a gastight seal and remains in a solid-like state under typical fuel cell operating conditions. Calcium alumina s…
Reflection and transmission of optical narrow-extent pulses by axially excited chiral sculptured thin films
Chiral sculptured thin films (STFs) have unidirectionally periodic electromagnetic constitutive properties and therefore exhibit the circular Bragg phenomenon. The time-domain Maxwell equations are solved using finite difference calculus in order to establish the spatiotemporal anatomy of the action of axially excited…
Nonlinear Properties of Waveguides with Twisted Nematic Liquid Crystal
Optical reorientational nonli neari ty in tw isted nematic li quid crystallin e planar w aveguide is analyzed theoreticall y. It is shown that optical nonlinearity for guided mo des in analyzed w aveguides can be appro ximated by saturation nonlin earity . Predicted nonlinear ity is large enough to observe eects like…
Rim Characteristics and Their Effects on the Thermal Conductivity in High Burnup UO2Fuel
Characteristics of high burnup UO2 fuel such as threshold burnup for the formation of high burnup microstructure (rim), rim average burnup and rim width were estimated and then the thermal conductivity degradation due to the porous rim region was investigated. The threshold burnup for rim formation was estimated as a…
Crystallization kinetics of poly(1,4-butylene-co-ethylene terephthalate)
The crystallization kinetics of poly(butylene terephthalate) (PBT), poly(ethylene terephthalate) (PET), and their copolymers poly(1,4-butylene-co-ethylene terephthalate) (PBET) containing 70/30, 65/35 and 60/40 molar ratios of 1,4-butanediol/ethylene glycol were investigated using differential scanning calorimetry (DS…
Recent Progress of SiC-Fibers and SiC/SiC-Composites for Fusion Applications
Recent progress in R&D of SiC fibers and reinforced SiC matrix (SiC/SiC) composites in Japan, especially focusing on the activities of CREST-ACE program, is presented. Firstly, the present status of high performance SiC fiber development, such as Hi-Nicalon Type-S and Tyrano-SA, is provided. The high performance SiC m…
Dynamic-Mechanical Properties of Ethylene/α-Olefin Copolymers Prepared by a Metallocene Catalyst
The influence of comonomer content and type on the dynamic-mechanical behavior of some ethylene/α-olefin (1-hexene, 1-octene, 1-decene, 1-octadecene and 4-methyl-1-pentene) copolymers was studied. It was observed that the comonomer content has great influence on α- and β-transitions, but almost no influence on γ-trans…
Hydroformylation of 1-Hexene over Co/SiO2 Catalysts: Influence of Pore Size of Support.
Silica-supported cobalt catalyst was studied for hydroformylation of 1-hexene. The influence of pore size of the silica support was investigated. It was found that cobalt catalyst supported on silica with appropriate pore size, about 6-10 nm, was active for the reaction with very high selectivity to oxygenates. The sm…
Hydrogen behavior during stress-corrosion cracking of an AZ31 magnesium alloy.
Hydrogen behavior during stress-corrosion cracking in an AZ31 magnesium alloy was studied by using hydrogen microprint technique (HMT), which is a method to visualize points of hydrogen emission from metals. Tensile test specimens were prepared from an extruded bar of the AZ31 magnesium alloy and deformed in tension a…
Characterization of Aspartate Kinase III of Bacillus subtilis
A search in the Bacillus subtilis genome sequence found that the gene designated yclM encode(s) a protein showing significant identity in amino acid sequence to aspartate kinases. When yclM was introduced into Escherichia coli cells deficient in all three aspartate kinase genes, production of a protein with molecular…
The Structure of Type-II Al-Ni-Co Decagonal Quasicrystal Studied by Atomic-Scale Electron Microscopic Observations
The structure of an Al–Ni–Co decagonal quasicrystal, showing electron diffraction patterns called “type-II”, in an Al71.5Ni12.5Co16 alloy, has been examined by high-angle annular detector dark-field scanning transmission electron microscopy and high-resolution transmission electron microscopy. Its structure has a colu…
Characterization of the Strain-amplitude and Frequency Dependent Damping Capacity in the M2052 Alloy
In order to reveal the damping behavior of M2052 alloy dependent on the strain-amplitude and frequency, a centrally excited beam sample was used in free-decaying and frequency sweeping damping measurement. The decaying oscillations and the resonant peaks were obtained directly by the surface strain of the sample. Freq…