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。
New enantiomerically pure binaphthyl derivatives bearing triphenylphosphine or phosphonate groups have been synthesized and used as building blocks to prepare the first optically active TTF and TCAQ dimers. Due to the restricted rotation of the two naphthalene rings, binaphthyl derivatives are ideal candidates to be u…
Serine hydroxymethyltransferase (SHMT) is a pyridoxal phosphate-dependent enzyme that catalyzes the reversible conversion of serine and tetrahydrofolate to glycine and methylenetetrahydrofolate. This reaction generates single carbon units for purine, thymidine, and methionine biosynthesis. The enzyme is a homotetramer…
The first hydrogen porous metallic membrane was a palladium tube with 1 mm wall thickness which T. Graham[1] used for measuring the hydrogen permeability at different temperatures. His experiments ...
Carbon nitride powder has been prepared by solid-state reaction between cyanuric chloride or its fluoro analogue and lithium nitride. The determined, by elemental analysis, atomic N/C ratio (1.33) in the synthesized material is entirely consistent with the C 3 N 4 stoichiometry. Combined material characterization data…
Heat capacities of the spin quantum number S = 1 / 2 two-dimensional Heisenberg antiferromagnet bis(2-amino-5-chloropyridinium) tetrabromocuprate(II) [(5CAP) 2 CuBr 4 ] crystal and its nonmagnetic analogue, the bis(2-amino-5-chloropyridinium) tetrabromozincate(II) [(5CAP) 2 ZnBr 4 ] crystal, were measured by adiabatic…
CdTe nanocrystals sequestered and passivated in an amorphous TiO 2 thin film matrix have been prepared by RF sputtering from a composite TiO 2 :CdTe target. The CdTe nanocrystal size and volume fraction increases from 15 to 40 nm and 2 to 20% respectively as the film thickness increases, typically from 0.05 to 0.25 µm…
Supramolecular enantiodifferentiating photoisomerization of (Z)-cyclooctene (1Z) to the chiral (E)-isomer (1E) via inclusion and sensitization by modified alpha-, beta-, and/or gamma-cyclodextrin derivatives, possessing benzoate (2a, 3a, 4a), isomeric phthalates (3b-d), and tethered benzamide (3e) chromophores, has be…
Photosensitive films incorporating molecular photoacid generators compartmentalized within a silica-surfactant mesophase were prepared by an evaporation-induced self-assembly process. Ultraviolet exposure promoted localized acid-catalyzed siloxane condensation, which can be used for selective etching of unexposed regi…
Hybrid systems of a semiconjugated organic polymer and single-wall nanotubes have been characterized by optical absorption spectroscopy, electron microscopy, and Raman spectroscopy. It is demonstrated that solutions of the polymer are capable of suspending nanotubes indefinitely while the majority of the accompanying…
From electronic structure calculations, we find that carriers injected into dangling-bond atomic wires on the Si(001) surface will self-trap to form localised polaron states. The self-trapping distortion takes the form of a local suppression of the buckling of the dimers in the wire, and is qualitatively different for…
We have determined the magnetic structures of the Dy and Fe sublattices in DyFe 6 Ge 6 by high-resolution neutron powder diffraction. The crystal space group is orthorhombic Cmcm . The Fe sublattice is antiferromagnetic with a Néel temperature of 489(1) K and it orders along the [100] direction with a magnetic space g…
In this paper, the formation of the different aggregates of a water-soluble tetracationic porphyrin, TMPyP, anchored to an anionic phospholipid matrix, DMPA, and assembled in LB films has been investigated. The use of different solid substrates such as hydrophilic glass and supports modified by the transfer of monolay…
Addition of [Cp*Ru(MeCN) 3 ]PF 6 to M(PcOEt) (PcOEt = octakis(ethoxy)phthalocyanine; M = H 2, Ni ( 1 ), Cu, VO) in dichloromethane results in the formation of {Cp*Ru[η 6 -M(PcOEt)]}PF 6 . The molecular structure of 1 reveals η 6 -coordination of Cp*Ru 2+ to one of the isoindole subunits of the phthalocyanine ligand. T…
We report on the magnetic and transport measurements in an Fe-doped colossal magnetoresistance compound (La 0.65 Ca 0.35 MnO 3 ). Increased spin disorder and a decrease of T c with increasing Fe content are evident. We find that the resistivity data above T p fits better to a variable range hopping model and the local…
Oxidation of a series of TTF vinylogues has been investigated in acetonitrile and dichloromethane. Depending on the substituent and the solvent, two single-electron transfers or one two-electron process was observed. Density functional modeling calculations and detailed analysis of the electrochemical behavior show th…
We use a density-functional based tight-binding method to study diamond growth steps by depositing dicarbon species onto a hydrogen-free diamond (110) surface. Subsequent C_2 molecules are deposited on an initially clean surface, in the vicinity of a growing adsorbate cluster, and finally, near vacancies just before c…
The adequate interpretation of scanning tunneling microscopy (STM) images of the clean Si(001) surface is presented. We have performed both STM observations and {\it ab initio} simulations of STM images for buckled dimers on the clean Si(001) surface. By comparing experimental results with theoretical ones, it is reve…
The distinction between absolute and convective instabilities is well known in the context of hydrodynamics and plasma physics. In this Letter, we examine an epitaxial crystal growth model from this point of view and show that a strain-induced step bunching instability can be convective. Using analytic stability theor…
It has been proposed recently that localized excitations and recombinations in the silanone Si O bond is the source for the red photoluminescence (PL) observed for oxygen-exposed porous silicon (PS). One concern with this proposal is the expected low chemical stability of the Si O bond. By using quantum chemistry calc…
Hexagonal (MCM-41) mesoporous materials were synthesized at 23 °C using hexadecyltrimethylammonium bromide (HDTMA) and tetramethyl-orthosilicate (TMOS) or Na-silicate. Products with (as-synthesized and dried at 23 or 70 °C) HDTMA removed significant amounts of trichlorethylene and tetrachloroethylene from water, simil…