Materials Literature
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Repetitive polypeptides of sequence [(AlaGly)3ProGluGly]16 3a, have been prepared in Escherichia coli as overexpressed recombinant proteins. Replacement of more than 90% of the naturally occurring proline (Pro) residues with 3,4-dehydroproline (Dhp) in sequence 3a was achieved by in vivo expression of the target prote…
Fourier transform Infrared (FTIR) analysis was applied to characterize the surface of atmospherically exposed metal plates. Early stages of atmospheric corrosion result in formation of corrosion films. Corrosion films are made up of layers of corrosion products initially caused from chemical reactions between the meta…
The dynamics of an 18-arm poly(isoprene) star polymer ${(M}_{n}^{\mathrm{arm}}$=7360 g/mol) is investigated by dynamic light scattering and viscometry. Above the overlap concentration ${c}^{*}$ the intensity autocorrelation functions show a two-step decay, which implies the existence of long range correlations, $\ensu…
A new material has been processed and characterized. It is a lightweight and high-damping composite formed by unidirectional Mg 2 Si fibres embedded in a pure magnesium matrix. This composite has been produced by unidirectional solidification of a Mg-Si near eutectic alloy (2 wt% Si). Mechanical strength was measured…
The effects of pressure (0.1−450 MPa) on enol−keto tautomerization reaction in salicylic acid (SA) have been investigated by steady-state absorption, fluorescence emission, and excitation spectroscopy. In dilute solutions, the emission intensity of the keto form of the monomer shows marked increase with pressure. In c…
Polarized Raman and infrared spectra of bis(thiourea)cadmium chloride, a novel semiorganic nonlinear optical crystal, were recorded to determine the symmetries of molecular vibrations. The observed Raman and infrared bands are assigned to molecular vibrations of thiourea, cadmium–sulphur and cadmium–chloride bonds. Th…
Fully cyclized, organo soluble, phenylethynyl-terminated, ether-imide oligomers of 2–10,000 g/mol (Mn) were prepared by the reaction of 2,2′-bis[4-(3,4-dicarboxyphenoxy)phenyl]-propane dianhydride (bisphenol-A dianhydride, BPADA) with a stoichiometric excess of either para, meta, or isomeric mixtures of phenylene diam…
The reduction of nitric oxide by propene in the presence of excessive oxygen over Pt/ZSM-5 has been investigated by in situ diffuse reflectance infrared Fourier transform spectrometry (DRIFTS) over a wide range of temperatures. It has been found that the main surface species formed during the reaction at low temperatu…
The systematic presence of a spectrum has been observed that has been termed anomalous SERS in the spectra on silver sols of a set of monocarboxylic acids, characterized by being independent of the adsorbate that is initially added and whose bands cannot be correlated with the respective Raman solution spectra. It has…
The cationic amphiphilic cobalt(II) phthalocyanines have been prepared, and are characterized by UV-absorption spectra in water and organic solvents and in their mixtures. The monomer–dimer transformation equilibrium was affected by solvent polarity and the length of the alkyl chains in the amphiphilic parts. All comp…
Polymeric two- and three-dimensional, homo- and heterometallic oxalatebridged coordination compounds offer exciting opportunities, mainly in the fields of molecular magnetism and photophysics. Given that a large variety of magnetic phenomena have been reported so far from these molecular magnets, very limited experien…
The high-brilliance beamline (BL4/ID2) at the European Synchrotron Radiation Facility (ESRF) in Grenoble has been constructed with the emphasis on time-resolved small-angle X-ray scattering and macromolecular crystallography. It has been open to users for two years. The beamline has opened up new areas in small-angle…
The complex anion bis(azido)(tetraphenylporphinato)ferrate(III) has been synthesized and characterized by variable-temperature X-ray structure determinations, powder and single-crystal EPR, IR, and Mössbauer spectroscopy, and magnetic susceptibility measurements. The synthesis utilizes 18-crown-6 to solubilize sodium…
Abstract Specific volumes are presented for 4-n-pentyl-4´-cyanobiphenyl (5CB) and trans-4-(4´-octyl-cyclo-hexyl)-benzonitrile (8PCH) for temperatures between 300 and 370 K up to 300 MPa. The p,V m ,T data were determined for the liquid crystalline and isotropic phases, and partly also for the solid phase adjacent to t…
Microporous manganese oxides with layer and tunnel structures have been synthesized by methods such as redox precipitation, thermal and hydrothermal alteration, sol-gel processing, and microwave heating. The open frameworks of these materials are composed of edge and corner shared MnO6 octahedra, with the internal por…
Infra-Red spectra of a series of substituted salicylaldehyde and 2-hydroxy-naphthaldehyde Schiff bases were used to investigate enol-keto tautomeric equilibrium. Two model compounds, namely, salicylidinaniline and naphthylidinequinolineamine Schiff bases were used to represent the enol and keto forms, respectively. Fr…
Porous silicon electroluminescent devices have been fabricated from n-type substrates using indium tin oxide, hole-transporting poly(9-vinyl carbazole) and p-type nickel oxide films as hole injecting contacts. The addition of the polymer layer, which increases the contact area by penetrating into the porous microstruc…
The oxidation of vinyl and silyl enol ethers with aqueous hydrogen peroxide was first achieved by the use of peroxotungstophosphate (PCWP) as the catalyst. For example, the oxidation of 1-ethoxy-1-octene with a stoichiometric amount of 35% H(2)O(2) in the presence of PCWP (0.5 mol %) in a mixed solvent of methanol and…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTLow-Temperature Synthesis of Aluminum Sulfide as the Solvate Al4S6(NMe3)4 in Hydrocarbon SolutionRudolf J. Wehmschulte and Philip P. PowerView Author Information Department of Chemistry University of California Davis, California 95616 Cite this: J. Am. Chem. Soc. 1997,…
A bisphthalocyanine lutetium derivative substituted with benzo-15-crown-5 subunits, [(15C5) 4 Pc] 2 Lu ( 1 ), has been shown to form sandwich complexes with cations such as potassium ion, the complexes further form pillarlike aggregates. Light scattering studies have been carried out as a function of the ratio [K + ]/…