Materials Literature
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ADVERTISEMENT RETURN TO ISSUECommunication to the...Communication to the EditorNEXTNondestructive Measurement of a Glass Transition Temperature at Spin-Cast Semicrystalline Polymer SurfacesJ. Hyun, D. E. Aspnes, and J. J. CuomoView Author Information Department of Materials Science and Engineering, North Carolina Stat…
Solid electrolytes were prepared by the introduction of Li[(CF 3 SO 2 ) 2 N] into amorphous branched polymers and dendritic macromolecular hosts. These materials exhibit high ionic conductivity, but high concentrations of salt increase the glass transition temperatures, with an attendant decrease in ionic conductivity.
The first known paramagnetic, tetrahedral cyanide complex, [Mn(II)(CN)(4)](2)(-), is formed by the photoinduced decomposition of [Mn(IV)(CN)(6)](2)(-) in nonaqueous solutions or by thermal decomposition in the solid state. In acetonitrile or dichloromethane, photoexcitation into the ligand-to-metal charge transfer ban…
Time-dependent density functional calculations have been performed on the symmetry and spin-allowed E u excited states of the nickel tetrapyrrole series, NiP, NiPz, NiTBP, and NiPc. Optical spectra collected in noncoordinating solvents are presented for NiTBP, for the newly synthesized octaethyl nickel porphyrazine, N…
Polystyrene-based systems with varying donor−acceptor−donor (D−A−D) hydrogen bonding side chains were synthesized. Recognition interactions between these polymers and guest flavin 5 were studied through 1 H NMR titration experiments. Using these systems, we have shown that the efficiency of recognition between the pol…
We constructed, by the first-principles calculations, a magnetic phase diagram of Sr$_{2}$RuO$_4$ in the space spanned by structural distortions. Our phase diagram can qualitatively explain the experimental one for Ca$_{2-x}$Sr$_x$RuO$_4$. We found that the rotation and the tilting of RuO$_6$ octahedron are responsibl…
In this paper, we reported the structural properties and superconductivity of Mg(B1-xCx)2 compounds. Powder x-ray diffraction results indicate that the samples crystallize in a hexagonal AlB2-type structure. Due to the chemical activity of Mg powders, a small amount of MgO impurity phase was detected by x-ray diffract…
To gain insights into the fundamental and characteristic features of the surface of doped manganites, we constructed a general magnetic phase diagram of La$_{1-x}$Sr$_{x}$MnO$_3$ (001) surfaces in the plane spanned by $x$ and the bulk tetragonal distortion $c/a$, from the first-principles calculations. We found that t…
A fascinating class of patterns, often encountered in nature as meandering cracks on rocks, dried-out fields and tectonic plates is produced by the fracture of solids. Here we report the observation and modeling of an unusual type of patterns consisting of spiral cracks within fragments of a thin layer of drying preci…
We report on a numerical study of quantum diffusion over micron lengths in defect-free multi-walled nanotubes. The intershell coupling allows the electron spreading over several shells, and when their periodicities along the nanotube axis are incommensurate, which is likely in real materials, the electronic propagatio…
A new nonadentate ligand, N, N, N1, N1-[2,6-bis(3'-aminomethyl-1'-pyrazolyl)-4-phenylpyridine]tetrakis(acetic acid) (BPTA) for a Tb3+ fluorescent complex was synthesized. The Tb3+ complex is strongly fluorescent, having a large fluorescence quantum yield of 1.00 and very long fluorescence lifetime of 2.681 ms in 0.05…
Ultralong beltlike (or ribbonlike) nanostructures (so-called nanobelts) were successfully synthesized for semiconducting oxides of zinc, tin, indium, cadmium, and gallium by simply evaporating the desired commercial metal oxide powders at high temperatures. The as-synthesized oxide nanobelts are pure, structurally uni…
The proton conductivity in the hydrogen-bonded systems with strong correlations between protons is investigated theoretically in the context of the two-stage transport modeling approach. The distortions of the nearest ionic groups at the formation of the hydrogen bond are shown to be the reason for the strong proton–p…
We investigate the morphology of diblock copolymers in the vicinity of flat, chemically patterned surfaces. We use a Ginzburg−Landau free energy to describe the spatial variations of the order parameter in terms of a general two-dimensional surface pattern above the order−disorder transition. The propagation of severa…
Abstract This work deals with the cationic ring‐opening polymerization of the ester‐substituted cyclic carbonates 5‐methyl‐5‐benzoyloxymethyl‐1,3‐dioxan‐2‐one ( CC1 ) and 4‐benzoyloxymethyl‐1,3‐dioxan‐2‐one ( CC4 ). The polymerization was carried out with trifluoromethanesulfonic acid, methyl trifluoromethanesulfonate…
The surface plasmon polariton-enhanced Raman spectra of size-selected, matrix-isolated C 14 neutral clusters are presented along with the calculated vibrational frequencies for the ring and linear chain isomers. The Raman spectra show resonance enhancement over a range of excitation wavelengths from 457.9 to 514.5 nm.…
Two crystal structures of human ornithine transcarbamylase (OTCase) complexed with the substrate carbamoyl phosphate (CP) have been solved. One structure, whose crystals were prepared by substituting N-phosphonacetyl-L-ornithine (PALO) liganded crystals with CP, has been refined at 2.4 Å (1 Å = 0.1nm) resolution to a…
Abstract Cloud point and solution density data between 20 and 100°C and pressures to 3000 bar are presented for poly(lactide) (PLA) and poly(lactide‐co‐glycolide) (PLGA x , where the molar concentration of glycolide in the backbone x ranges from 0 to 50 mol %) in supercritical CO 2 , CHClF 2 , and CHF 3 . PLA dissolve…
Abstract 4‐Cyclohexylurazole (1) R = cyclohexyl (CHU) was prepared from cyclohexyl isocyanate in two steps. Polycondensation reactions of compound CHU with hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), and toluene‐2,4‐diisocyanate (TDI) were performed in DMAc/chloroform and DMAC in the presence of…
Abstract To improve the strengths of the adhesive joints of high density polyethylene (HDPE) and polypropylene (PP) to steel, the surfaces of HDPE and PP sheets have been treated by DC glow discharge to increase the polar component of surface energy significantly. Present study investigates the effect of mechanical po…