Materials Literature
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We used our previously implemented GW approximation (GWA) based on the all-electron full-potential projector augmented wave (PAW) method to study the optical properties of small, medium and large-band-gap semiconductors: Si, GaAs, AlAs, InP, Mg$_2$Si, C, and LiCl. The aim being to study the size of both local-field (L…
We have studied the dynamics of electrons in single wall carbon nanotubes using femtosecond time-resolved photoemission. The lifetime of electrons excited to the pi* bands is found to decrease continuously from 130 fs at 0.2 eV down to less than 20 fs at energies above 1.5 eV with respect to the Fermi level. This shou…
It was recently reported that water soluble conducting polyaniline may be prepared using a new template-guided enzymatic approach. To address the mechanistic role of the template in this reaction, various macromolecular and surfactant templates were investigated. It was found that the template provides a necessary typ…
Lewis acid mediated hydrosilylation of alkynes and alkenes on non-oxidized hydride-terminated porous silicon derivatizes the surface with alkenyl and alkyl functionalities, respectively. A very broad range of chemical groups may be incorporated, allowing for tailoring of the interfacial characteristics of the material…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTEnvironment-Sensitive Stabilization of Core−Shell Structured Polyion Complex Micelle by Reversible Cross-Linking of the Core through Disulfide BondY. Kakizawa, A. Harada, and K. KataokaView Author Information Department of Materials Science Graduate School of Engineeri…
Reactions of [Fe II (CN) 2 (bpy) 2 ] and [Fe III (CN) 2 (bpy) 2 ](PF 6 ) with [Cu II (bpy)(CH 3 OH) 2 ](PF 6 ) 2 in methanol yielded cyanide-bridged cyclic tetranuclear complexes of [Fe II 2 Cu II 2 (μ-CN) 4 (bpy) 6 ](PF 6 ) 4 ·2H 2 O·4CHCl 3 ( 1 ) and [Fe III 2 Cu II 2 (μ-CN) 4 (bpy) 6 ](PF 6 ) 6 ·4CH 3 CN·2CHCl 3 (…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTSynthesis of [28]Heptaphyrin(1.0.0.1.0.0.0) and [32]Octaphyrin(1.0.0.0.1.0.0.0) via a Directed Oxidative Ring Closure: The First Expanded Porphyrins Containing a Quaterpyrrole SubunitJonathan L. Sessler, Daniel Seidel, and Vincent LynchView Author Information Departmen…
We present a detailed molecular-dynamics study of the diffusion and coalescence of large (249-atom) gold clusters on graphite surfaces. The diffusivity of monoclusters is found to be comparable to that for single adatoms. Likewise, and even more important, cluster dimers are also found to diffuse at a rate which is co…
We study several one dimensional step flow models. Numerical simulations show that the slope of the profile exhibits scaling in all cases. We apply a scaling ansatz to the various step flow models and investigate their long time evolution. This evolution is described in terms of a continuous step density function, whi…
Polypropylene now has a history of nearly 45 years since its discovery and 40 years since its commercialization. It has established itself as one of the most important polymers that has engineering plastic properties at commodity plastics prices. The end of the growth of polypropylene is not in sight.
With a view to further refining the use of the exceptional group G 2 in atomic and nuclear spectroscopy, it is confirmed that a simple finite subgroup L 168 ~ PSL 2 (7) of order 168 of the symmetric group S 8 is also a subgroup of G 2 . It is established by character theoretic and other methods that there are two dist…
Traditional stabilization systems for polypropylene are typically based on a binary combination of a phenolic antioxidant and a phosphorus based melt processing stabilizer. The phenolic antioxidant provides melt processing stability as a hydrogen atom donor and free radical scavenger; it also provides the polymer with…
For spin-polarized low-energy electrons impinging on non-magnetic crystalline surfaces, the collision with a valence electron and the ensuing emission of an electron pair are treated in a distorted-wave Born approximation formalism with exchange, in which the four relevant quasi-one-electron states are solutions of th…
The progresses obtained in both catalyst performances and process technologies have made the continuous expansion of PP properties possible. The discovery of MgCl2-supported catalysts and the development of their controlled spherical morphology produced a real revolution in the catalytic-system performances. A series…
We have shown in the present article, starting from the high capacity PP′s on the market, the development of long-chain branched PP which means melt strength PP. As a basis, the radical mechanism were used to synthesize long-chain branched PP. Most known is the process at low temperature by using electron-beam-irradia…
Boron carbide-filled (BN) x C y nanotubes with outer layers of pure carbon and inner layers of pure boron nitride (BN) have been synthesized for the first time in high yield by using pure carbon nanotubes (CNTs) as templates. The (BN) x C y nanotubes form by capillary filling of boron oxide vapor condensed into the in…
We report an investigation of how much protein structural information could be obtained using a site-directed fluorescence labeling (SDFL) strategy. In our experiments, we used 21 consecutive single-cysteine substitution mutants in T4 lysozyme (residues T115-K135), located in a helix-turn-helix motif. The mutants were…
The preparation and characterization of two crystalline forms of [Fe(TMP)(5-MeHIm) 2 ]ClO 4 with distinctly different molecular structures are reported. Crystal structure analysis shows that paral -[Fe(TMP)(5-MeHIm) 2 ]ClO 4 has the axial imidazole ligands arranged in a relative parallel orientation (over a slightly S…
Unoccupied density of states (DOS) for the polar (0001) Zn, (000 ) O and non-polar (10 0) ZnO surfaces and for a MgO(001)-c(2 × 2) thin film were studied using total current spectroscopy (TCS). TC spectra of the ZnO surfaces reveal the Zn 4s-O 2p band (6.2 eV) and two DOS maxima in the Zn 4p-O 2p band which exhibited…
Recent progress in transition metal catalyzed propylene polymerization based upon single-site catalysts and melt compounding of polypropylene is stimulating the development of novel polypropylene materials with unconventional property combinations such as improved low temperature toughness, low haze, elasticity, and i…