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。
Vibrationally resolved photoelectron spectra are obtained for the small TiC x - ( x = 2−5) clusters. Adiabatic electron affinities (EAs) and low-lying electronic states are measured for the neutral TiC x clusters. While the EAs are similar for the series of clusters, 1.542 eV for TiC 2, 1.561 eV for TiC 3, 1.494 eV fo…
Synthetic routes to soluble planar poly(phenylenethiophene)s and polythiophenes are described. The main polymer backbones are synthesized via Pd(0)-catalyzed couplings of the electron-rich N,N ‘-(bis- tert -butoxycarbonyl)-3,4-diamino-2,5-bis(tri- n -butylstannyl)thiophene with electron-deficient aryldibromodiones. Th…
The compounds [Mn 2 (bpm) 3 (NCS) 4 ] ( 1 ), [Mn(bpm)(NCO) 2 ] ( 2 ), and [Mn 2 (bpm)(N 3 ) 4 ] ( 3 ) (where bpm= 2,2‘-bipyrimidine) have been synthesized and characterized. Compound 1 crystallizes in the triclinic P 1̄ space group, with a = 9.122(1) Å, b = 9.229(1) Å, c = 11.710(2) Å, α = 74.89(1)°, β = 80.30(1)°, γ…
Measurements of antiproton stopping powers around the stopping-power maximum are presented for targets of Al, Si, Ti, Cu, Ag, Ta, Pt, and Au. The Low Energy Antiproton Ring antiproton beam of 5.9 MeV is degraded to 50--700 keV, and the energy loss is found by measuring the antiproton velocity before and after the targ…
High-angle annular dark-field (HAADF) images of an Al 72 Ni 20 Co 8 decagonal quasicrystal have been taken for the first time. It has been found that the transition metals form pentagonal and star-shaped cluster columns with radii of about 0.4 nm. The atom-cluster columns with a 2 nm diameter of the alloy, which have…
In this paper we present results from molecular dynamics simulations performed using a system of Gay-Berne particles confined between two substrates in a slab geometry. We use a nonseparable anisotropic molecule-substrate interaction potential and investigate weak and moderate molecule-substrate coupling strengths. We…
Optical properties of Cd y Zn 1 - y S nanoparticles differing by their size and composition are presented. The fluorescence quantum yield increases with increasing particle size and composition ( y ). The photoluminescence, PL, spectra are due to defect states and follow the quantum size effect. A red-shift in the flu…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTApplication of X-ray Powder Diffraction Techniques to the Solution of Unknown Crystal StructuresDamodara M. Poojary and Abraham ClearfieldView Author Information Department of Chemistry, Texas A & M University, College Station, Texas 77843 Cite this: Acc. Chem. Res. 1997, 30…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTLarge Variations in 13Cα Chemical Shift Anisotropy in Proteins Correlate with Secondary StructureNico Tjandra and Ad BaxView Author Information Laboratory of Biophysical Chemistry National Heart, Lung, and Blood Institute Laboratory of Chemical Physics National Institu…
We have used scanning force microscopy and transmission electron microscopy to study the microphase separation of P(S- b- 2VP) block copolymers on chemically structured substrates. Gold was patterned by microcontact printing to form regions of self-assembled alkyl monolayers terminated by −CH 3 or −OH. The differences…
A bulk bundle (with a diameter of about 100 µ m) of single-walled nanotubes (SWNTs), which were obtained after a purification process of carbon soot containing SWNTs, was used as an electron emitter. Many spikes of micro-bundles (with a typical diameter of 20–30 nm) of SWNTs extruded from the surface of the bulk emitt…
The phenomenology of the subglass relaxation processes as a function of temperature is investigated, taking as a probe system the β relaxation behavior of a main chain segmented liquid crystalline polyester. Real ( E ‘) and imaginary parts ( E ‘‘) of the modulus were measured as a function of temperature in isochronal…
Elevated temperature STM has been used to obtain atomic resolution images of flat regions, defect sites and step edges on the (001) surface of crystalline nickel oxide. Identification of surface lattice sites seen in empty and filled states (nickel and oxygen sites, respectively) is consistent with recent theoretical…
Abstract Styrene derivatives with pendant cyclotriphosphazenes carrying ethoxy ( 1 ) and ethylene glycol monomethyl ether groups (O(CH 2 CH 2 ) n CH 3 : 2 , n = 1; 3 , n = 2; 4 , n = 3) and their (co)polymers were prepared, and the selective binding and transport toward silver picrate by these ligands were examined. T…
Abstract Well‐defined block and graft copolymers of different types with different compositions and molecular weights, such as styrene(S)‐2‐vinylpyridine(P) diblock copolymers, SP star‐shaped block copolymers, PSP triblock copolymers, styrene(S)‐isoprene(I) multiblock copolymers of the (SI) n type, ISP triblock copoly…
Cadmium oxide films obtained by magnetron sputtering of a cadmium target in a nitrogenoxygen mixture are investigated. It is established that these films have a lower resistivity than do films obtained by other methods. It is concluded that the practical utilization of CdO films as transparent electrodes would be wort…
Abstract An elecron-transfer complex of a substituted manganese porphyrin with tetracyanoethylene was prepared. Crystal structure analysis revealed that there exists quasi-two dimensional interaction in the complex, which was shown to be a magnet with Tc of 6.0 K.
The fracture toughness of single‐crystal YAG was measured as a function of temperature in air and under vacuum using the SENB technique up to 1600°C. The measured KIC was 2.2 MPa·m 1/2 at room temperature and it increased with temperature above 1200°C, reaching a value of 4.5 MPa·m 1/2 at 1600°C in air. The effects of…
Abstract Platinum electrode modified with polyaniline by electropolymerization exhibits amperometric sensitivity to nonprotonated ammonia in aqueous solutions in the anodic range of potentials. Sensitivity of response depends mostly on the kind of doping anions used and the polarization potential applied during measur…
Abstract Miargyrite is the low-temperature monoclinic derivative of a high temperature cubic galena/halite structure. The essential features of its crystal structure (Knowles, 1959) were confirmed, but the details of the bonding changed [new space group C 121; a 12.824(1), b 4.4060(3), c 13.193(1) Å, β 98.567(6)°]. Th…