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。
We report experimental evidence showing a direct correlation between the alignment of carbon nanofibers (CNFs) prepared by plasma-enhanced chemical-vapor deposition and the location of the catalyst particle during CNF growth. In particular, we find that CNFs that have a catalyst particle at the tip (i.e., growth proce…
Of the ``presolar particles'' extracted from carbonaceous chondrite dissolution residues, i.e. of those particles which show isotopic evidence of solidification in the neighborhood of other stars prior to the origin of our solar system, one subset has an interesting concentric graphite-rim/graphene-core structure. We…
Small polaron behavior in a two dimensional honeycomb net is studied by applying the strong coupling perturbative method to the Holstein molecular crystal model. We find that small optical polarons can be mobile also if the electrons are strongly coupled to the lattice. Before the polarons localize and become very hea…
We study the Aharonov-Bohm effect in a coupled 2$\times$2 quantum dot array with two-terminals. A striking conductance dip arising from the Fano interference is found as the energy levels of the intermediate dots are mismatched, which is lifted in the presence of a magnetic flux. A novel five peak structure is observe…
The syntheses and crystal structures of the eight-membered cyclo -stannasiloxanes cyclo -[ t -Bu(OH)Si(OSn t -Bu 2 O) 2 Si(OH) t -Bu] ( 1 ) and cyclo -{ t -Bu 2 Si[OSn(CH 2 SiMe 3 ) 2 O] 2 Si t -Bu 2 } ( 2 ) as well as the synthesis of the six-membered cyclo -stannasiloxane cyclo -{ t -Bu 2 Si[OSn(CH 2 SiMe 3 ) 2 ] 2…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTBridging the Ruddlesden−Popper and the Aurivillius Phases: Synthesis and Structure of a Novel Series of Layered Perovskite Oxides, (BiO)LnTiO4 (Ln = La, Nd, Sm)Thathan Sivakumar, Ram Seshadri, and Jagannatha GopalakrishnanView Author Information Solid State and Structu…
Dynamic secondary ion mass spectrometry was performed to determine the dynamics of thin free-standing polystyrene films by investigating probe diffusion in a high molecular weight polymer matrix. It is found that the temperature dependence of the diffusion of small molecular probes can be described by the WLF equation…
The gelation and gel-melting processes have been investigated by time-resolved dynamic light scattering for gelatin aqueous solutions (1) during both cooling and heating processes with a fixed rate (0.10 °C/min) and (2) after quenching from 50 to 10 °C. In both cases, the gelation threshold was clearly observed as (i)…
The crystal structure of hexagonal LuMnO3 at room temperature is isomorphous with YMnO3 and deviates in important details from the early work of Yakel et al. [Acta Cryst. (1963), 16, 957–962]. Mn is near the centre of its oxygen coordination environment. On the threefold axes, the apical O—Lu bonds have alternating l…
We report the first synthesis and characterization of nanocrystalline Bi 2 Te 3 with particle sizes less than 10 nm. The reaction of BiOClO 4 · x H 2 O with (Me 3 Si) 2 Te in a reverse micelle formed by sodium dioctylsulfosuccinate and water in hexane has produced good yields (71%) of a black powder that has been char…
We present a versatile method, based on the electrostatic self-assembly of oppositely charged species onto sacrificial templates, for the preparation of nanotubes. Polymer and polymer composite nanotubes were prepared by the layer-by-layer (LbL) deposition of polyelectrolytes and/or a charged inorganic molecular precu…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTFluorous Catalysis without Fluorous Solvents: A Friendlier Catalyst Recovery/Recycling Protocol Based upon Thermomorphic Properties and Liquid/Solid Phase SeparationMarc Wende, Ralf Meier, and J. A. GladyszView Author Information Institut für Organische Chemie Friedric…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTMolecular Recognition Inside of Multifunctionalized Mesoporous Silicas: Toward Selective Fluorescence Detection of Dopamine and GlucosamineVictor S.-Y. Lin, Cheng-Yu Lai, Jianguo Huang, Se-Ahn Song, and Shu XuView Author Information Department of Chemistry, Iowa State…
The mean-square optical anisotropy 〈Γ 2 〉 was determined from anisotropic light scattering measurements for nine samples of poly( n -hexyl isocyanate) (PHIC), a typical semiflexible polymer, in the range of weight-average molecular weight from 1.65 × 10 4 to 1.04 × 10 5 in n -hexane at 25.0 °C. It was found that the b…
The Debye equation gives the spherically averaged diffracted intensity from a group of atoms and is exact under the first Born, or kinematic, approximation. Algebraic simplifications are developed for calculating multiplicities in the double summation and are used in a new algorithm for implementing this equation. The…
Abstract Sb‐doped ZnO nanocrystallites of average grain size about 10 nm were made by using the citrate method. Raman spectra of the Sb‐doped ZnO nanocrystallites at room temperature are reported. Shifts and broadening of the Raman peak with Sb increasing content were observed and it was found that the intensity of a…
Abstract Hot‐stage optical microscopy was used to study the crystal morphology, nucleation, and spherulitic growth rates of poly( p ‐dioxanone) (PDS) homopolymer and an 89/11 PDS/glycolide segmented block copolymer. A wide range of crystallization conditions were experimentally accessible, allowing the inspection of v…
Highly aligned carbon nanotubes (NTs) have been directly grown on metallic surfaces and in the channels of anodic aluminum oxide (AAO) templates at a low temperature by bias-enhanced microwave plasma chemical vapor deposition. Microwave plasma generated nanoparticles of various sizes (10−100 nm) on metallic surfaces,…
Although a commonly neglected fact, the physical properties of chiral carbon nanotubes may differ significantly from those of the usually considered, simpler achiral tubes. We show that the phonon eigenvectors, e.g., of the high-energy eigenmodes no longer fall into axial and circumferential modes as in armchair and z…
We have determined the crystal structure of MTH938 (Fig. 1), a hypothetical protein encoded by the Methanobacterium thermoautotrophicum (Mthe) genome (DNA bases 843,263–862,747),1 at 2.2 Å resolution by Se-Met multiwavelength anomalous diffraction (MAD) techniques. Se-Met labeled MTH938 crystallized with the symmetry…