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 present a systematic methodology for the accurate calculation of defect structures in supercells which we illustrate with a study of the neutral vacancy in silicon. This is a prototypical defect which has been studied extensively using ab initio methods, yet remarkably there is still no consensus about the energy o…
Comment on F. Wilhelm et al., Phys. Rev. Lett. 87, 207202 (2001)
Weakly nonlocal thermodynamic theories are critically revisited. A relocalized, irreversible thermodynamic theory of nonlocal phenomena is given, based on a modified form of the entropy current and new kind of internal variables, the so called current multipliers. The treatment is restricted to deal with nonlocality c…
A phase transition in an organic charge-transfer complex, which originates from the neutral-ionic valence instability, can be tuned toward zero kelvin with use of external pressure or chemical modification as a control parameter. The phase diagram and observed dielectric behaviors are typical of quantum paraelectricit…
We report the first example of a transition to long-range magnetic order in a purely dipolarly interacting molecular magnet. For the magnetic cluster compound ${\mathrm{M}\mathrm{n}}_{6}{\mathrm{O}}_{4}{\mathrm{B}\mathrm{r}}_{4}({\mathrm{E}\mathrm{t}}_{2}\mathrm{d}\mathrm{b}\mathrm{m}{)}_{6}$, the anisotropy experienc…
Langevin equation pertinent to diffusion limited aggregation of charged particles in the presence of an external magnetic field is solved exactly. The solution involves correlated random variables. A new scheme for exactly sampling the components of the position and velocity is proposed.
The 2p core excited XAS and XMCD spectra of Cr$_{1-δ}$Te with several concentrations of $δ$=0.11-0.33 have been measured. The observed XMCD lineshapes are found to very weakly depend on $δ$. The experimental results are analyzed in terms of the configuration-interaction picture with consideration of hybridization and…
We introduce a new class of foldable oligomers consisting of alternating rigid and flexible regions. The rigid segments overlap to give pi-stacked folded conformers whose formation is driven mostly by pi-pi molecular orbital overlaps. As the oligomer concentration increases, the folded molecular structures further sel…
We investigated ferromagnetism of a newly discovered ferromagnetic semiconductor Co-doped anatase ${\mathrm{T}\mathrm{i}\mathrm{O}}_{2}$ thin film, using the magnetic circular dichroism (MCD) at the Co ${L}_{2,3}$ absorption edges. The magnetic moment was observed to be $\ensuremath{\sim}0.1{\ensuremath{\mu}}_{B}/\mat…
The self-assembly of particles at fluid interfaces, driven by the reduction in interfacial energy, is well established. However, for nanoscopic particles, thermal fluctuations compete with interfacial energy and give rise to a particle-size-dependent self-assembly. Ligand-stabilized nanoparticles assembled into three-…
A study of miscibility, morphology, crystallization, and dynamic mechanical properties of polypropylene in the presence of a low-molecular-weight compound, hydrogenated dicyclopentadiene (DCPD), is described. Differential scanning calorimetry (DSC), optical microscopy (OM), and dynamic mechanical analysis (DMA) were u…
Blends of ethylene propylene diene terpolymer (EPDM) rubber with thermoplastic polyolefins such as low‐density polyethylene (LDPE), high‐density polyethylene (HDPE), high molecular weight polypropylene (PP), and polypropylene random copolymer grade (PP‐R) were prepared by melt mixing. The physico‐mechanical properties…
Elemental germanium and other metals, including Cu, In, Ag, Bi, Sn, and In, are transported under acidic ammonothermal conditions from the hot zone of a sealed quartz tube to the cool zone, where both crystalline and amorphous materials can deposit. Red amorphous Ge deposits when finely divided Ge that is covered with…
The thermal conductivity of polymers in the solid and molten phases, as functions of temperature and pressure, is an essential parameter to permit simulation of polymer processing by computer-aided engineering (CAE). A key factor for the thermal conductivity when used in CAE is the Bridgman parameter (g) as a function…
The effects of agitation in emulsion copolymerization have been studied using a semibatch emulsion copolymerization recipe that gave a latex with ca. 44 wt% solids. The two‐stage polymerization process consisted of an in situ seed‐formation step followed by copolymerization of the continuously added n‐butyl methacryla…
A G4.0 polymelamine dendrimer based on silica gel (PMDSG) was fabricated via a divergent approach via repetitive reaction of 2,4,6-trichloro-1,3,5-triazine and 1,6-hexylenediamine from a γ-aminopropyl silica gel (APSG) core for the first time. It was then used as the microcolumn packings for the flow injection (FI) pr…
We show that the polycrystalline perovskite antiferromagnet Pr0.5Sr0.5MnO3 exhibits a giant anisotropic magnetostriction (λt=1.5×10−3 at T=25 K and H=14.2 T) contrary to much smaller λt (<0.1×10−3) found in most other three-dimensional manganites. The value of λt decreases rapidly as the Néel temperature is app…
Photostimulated discharge spectroscopy of cellular polypropylene films between 200 and 400 nm showed the existence of at least three distinct trapping levels at 4.6, 5.6, and 6.3 eV. The effects of UV irradiation on the piezoelectric d33 coefficient was studied by monitoring thickness-extension resonances in the diele…
The equilibrium and nonequilibrium segmental dynamics of bisphenol-A-polycarbonate (PC) have been investigated near the glass transition by studying the rotational and translational diffusion of probe molecules in the polymer matrix. The temperature dependence of equilibrium dynamics was studied from 149 to 124 °C. We…
Jute yarns were pretreated by alkali (5% NaOH) and were grafted with two types of monomer such as 3‐(trimethoxysilyl)‐propylmethacrylate (silane) and acrylamide (AA) under ultraviolet (UV) radiation. The monomer concentrations were 30% in Methanol (MeOH) and irradiation times were 30 min and 60 min for silane and AA,…