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。
First-principles band calculations are performed for the first time for an open-structured zeolite (LTA) with guest atoms (potassium) introduced in their cages. A surprisingly simple band structure emerges, which indicates that this system may be regarded as a "supercrystal", where each cluster of guest atoms with dia…
The bamboo-shaped carbon nanotubes were synthesized on a large scale through an ethanol thermal reduction process, in which ethanol was used as the carbon source and magnesium was used as the reductant. The toxic or corrosive reagents have been completely avoided. Furthermore, Y-junction carbon nanotubes obtained from…
The final stage of latex film formation was simulated by introducing donors and acceptors into the adjacent compartments of a cube. Homogenous and/or heterogeneous donor-acceptor distributions were chosen for different types of simulations. The interdiffusion of the donors and the acceptors within these cubes was gene…
The closely related phases alpha- and beta-A(2)Hg(3)M(2)S(8) (A = K, Rb; M = Ge, Sn) have been discovered using the alkali polychalcogenide flux method and are described in detail. They present new structure types with a polar noncentrosymmetric crystallographic motif and strong nonlinear second-harmonic generation (S…
We investigated the upconversion properties of nanocrystalline and bulk Y 2 O 3:Er 3+ as a function of the erbium concentration (1, 2, 5, 10, 25, and 35 mol %). Following excitation with 980 nm, upconverted emission is observed from the 2 H 11/2, 4 S 3/2, and 4 F 9/2 excited states to the 4 I 15/2 ground state centere…
The excited-state dynamics of trans-azobenzene were investigated by femtosecond time-resolved photoelectron spectroscopy and ab initio molecular dynamics. Two near-degenerate pipi* excited states, S2 and S3,4, were identified in a region hitherto associated with only one excited state. These results help to explain co…
Abstract The dielectric properties of lanthanum (La) and titanium (Ti) modified SBN ceramics were investigated in this work. The ferroelectric to paraelectric transition temperature is found to be sensitive to the substitution degree of host ions. In particular, high values of permittivity at room temperature and a st…
The intrinsic linewidth of Ag(100) electronic image-potential states versus the momentum parallel to the surface has been obtained from line-shape analysis of high-resolution angle-resolved two-photon photoemission spectra. For the $n=1$ state, the measured intrinsic linewidths have been observed to increase from 14 m…
The anharmonic decay rates of atomic vibrations in amorphous silicon $(a$-Si) and paracrystalline silicon $(p$-Si), containing small crystalline grains embedded in a disordered matrix, are calculated using realistic structural models. The models are 1000-atom four-coordinated networks relaxed to a local minimum of the…
ADVERTISEMENT RETURN TO ISSUEPREVNoteSynthesis and Thermal Properties of Hydrogenated Poly(styrene-co-1,1-diphenylethylene) CopolymersJing J. Xu and Frank S. BatesView Author Information Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455 Cite this: Macromole…
Abstract Microhardness tests, Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC) measurements were performed on melt‐pressed films of multicomponent blends based on low‐density polyethylene (LDPE), linear LDPE (LLDPE), high‐density polyethylene (HDPE), and polypropylene (PP), a…
In this Letter, crystal growth of a symmetric crystalline−amorphous diblock copolymer, poly(styrene- b -ε-caprolactone) (PS- b -PCL), in thin films was investigated by atomic force microscopy (AFM). Relief structures of holes and islands were formed during annealing the film at the molten state, and the in situ observ…
A novel tubular form of graphitic boron nitride (BN) displaying a hollow conical-helix was discovered. It was generated via wrapping a single beltlike filament according to the geometry of an Archimedes spiral. Cone apex angles of helical-conical nanotubes (HCNTs) were found to exhibit specific values, each of which r…
We report on experiments of light transmissivity, at wavelengths of 532 nm and 400 nm, through an Au film with a wedge shape. Our results exhibit a resemblance with those reported for observing negative refraction in proposed left-handed materials. This resemblance is present even though the medium that we used is wel…
A novel sol−gel route based on aluminum lactate and sodium polyphosphate aqueous solutions has been developed to produce sodium aluminophosphate gels and glasses with the composition 43.8:12.5:43.8 Na 2 O/Al 2 O 3 /P 2 O 5 . Preparations were optimized on the basis of detailed 27 Al solution- state NMR data, revealing…
First-principles studies of the geometry and energetics of the ${\mathrm{Si}}_{36}$ cluster are performed by searching 17 structural isomers including cage, wire, and stuffed fullerene. It is found that the tricapped-trigonal-prism unit is not the structural unit for ${\mathrm{Si}}_{36},$ and the stable structure is i…
We have investigated the magnetic and transport properties of ${\mathrm{Pr}}_{0.65}{\mathrm{Ca}}_{0.35}{\mathrm{MnO}}_{3}$ and ${\mathrm{Pr}}_{0.82}{\mathrm{Na}}_{0.18}{\mathrm{MnO}}_{3}$ with almost the same doping level under various magnetic fields. Upon applying a field of 4 T, both compounds undergo a metamagneti…
We have used scanning tunneling microscopy and potentiometry to study the microstructure and nanoscopic current transport in thin films of ${\mathrm{La}}_{0.7}{\mathrm{Ca}}_{0.3}{\mathrm{MnO}}_{3}$ grown on ${\mathrm{SrTiO}}_{3}$ and ${\mathrm{NdGaO}}_{3}$ substrates. Thin (50 nm) films, which are strained, show step-…
Abstract Maleated polyethylene/silicate nanocomposite and maleated polyethylene/SiO 2 blown films were prepared by melt extrusion. The silicate and SiO 2 significantly affected the physical properties of the films. The former films showed higher tensile strength than the latter films. This high reinforcement effect se…
Abstract Although poly(ethyl methacrylate) (PEMA) and poly(methyl methacrylate) (PMMA) are only slightly different in structure, they are known to be immiscible. Polystyrene is not miscible with PEMA or PMMA. However, when polystyrene is modified to contain certain vinyl phenol groups to become poly(styrene‐ co ‐vinyl…