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。
Abstract One of the most common methods of preventing downhole and topside mineral scale formation in oilfields is through the use of chemical scale inhibitors. Several aspects of the brine composition may affect the performance of the various scale inhibitors used in oilfield applications. In this paper, we focus on…
Hen egg-white lysozyme dissolved in glycerol containing 1% water was studied by using CD and amide proton exchange monitored by two-dimensional 1H NMR. The far- and near-UV CD spectra of the protein showed that the secondary and tertiary structures of lysozyme in glycerol were similar to those in water. Thermal meltin…
Permalloy (Py:Ni81Fe19) exhibits an anisotropic magnetoresistance (AMR) which is very often used to read magnetic signals from storage devices. Py-films of thickness 20nm were prepared by dc-magnetron sputtering in a magnetic field onto thermally oxidized Si-wafers and annealed ex situ at temperatures up to 1000K in o…
We use computer simulations to study the behavior of atomically sharp and blunted cracks in various f.c.c. metals. The simulations use effective medium potentials which contain many-body interactions. We find that when using potentials representing platinum and gold a sharp crack is stable with respect to the emission…
Photochemical release (uncaging) of bioactive messengers with three-dimensional spatial resolution in light-scattering media would be greatly facilitated if the photolysis could be powered by pairs of IR photons rather than the customary single UV photons. The quadratic dependence on light intensity would confine the…
We examined the effects of the tie-molecule fraction on the yielding behavior of two isotactic polypropylenes, one having little ethylene content and the other as the homopolymer with no ethylene. The tie-molecule fraction of the samples used in this study was controlled by blending ethylene-α-olefin of an α-olefin co…
A new class of thermally robust sol-gel polymers have been prepared from the disilaoxacyclopentane derivative 1 by ring-opening polymerization to form nonshrinking polysiloxanes. This reaction, which does not need solvent or water, can be used for, amongst other things, the encapsulation of an electronic microchip.
A region of broad nonlinear curvature is observed in DSC traces of ABA copolymers during temperature sweeps between the glass transition temperatures of the two principal microphases. This curvature is attributed to a smoothly varying composition profile through the interfacial region lying between microphases. The sh…
The electronic and magnetic states in doped perovskite cobaltites, $(\mathrm{L}\mathrm{a},\mathrm{S}\mathrm{r}){\mathrm{CoO}}_{3},$ are studied in the numerically exact diagonalization method on ${\mathrm{Co}}_{2}{\mathrm{O}}_{11}$ clusters. For realistic parameter values, it is shown that a high spin state and an int…
The dodecameric type II dehydroquinases (DHQases) have an unusual quaternary structure in which four trimeric units are arranged with cubic 23 symmetry. The unfolding and refolding behaviour of the enzymes from Streptomyces coelicolor and Mycobacterium tuberculosis have been studied. Gel-permeation studies show that,…
Aromatic liquid crystalline epoxy resin (LCE) based on naphthalene mesogen was synthesized and cured with aromatic diamines to prepare heat-resistant LCE networks. Diaminodiphenylester (DDE) and diaminodiphenylsulfone (DDS) were used as curing agents. The curing reaction and liquid crystalline phase of LCE were monito…
SCD (spin-singlet charge density) description of electron-hole exchange interaction is shown to provide a bridge among the various traditional ways of description of LT splitting of polarization modes, i.e., the interaction among the induced polarization charge, electron-hole exchange interaction (for excitons), and t…
The electronic structures of organic solids ${(\mathrm{C}\mathrm{H}}_{3}{)}_{4}{\mathrm{N}[\mathrm{Ni}(\mathrm{dmit})}_{2}{]}_{2}$ and $\ensuremath{\beta}\ensuremath{-}{(\mathrm{C}\mathrm{H}}_{3}{)}_{4}{\mathrm{N}[\mathrm{Pd}(\mathrm{dmit})}_{2}{]}_{2}$ (dmit=2-thioxo-1,3-dithion-4,5-dithiolate) are studied by first-p…
The characteristics of the diffuse phase transition of Pb(Fe2/3W1/3)O3 relaxor ceramics doped with different amounts of Mn are investigated. The freezing temperature Tf, obtained by fitting the ω,Tmax to the Vogel–Fulcher relationship, clearly changes with the Mn content. It increases as the Mn content increases, appr…
The formation of nanosized crystallites of magnetite, Fe3O4, by heat treatment of a glass containing iron oxide was investigated. The magnetic properties of the glass ceramic manufactured strongly depend on the heat treatment conditions. The evolution of size distribution and volume fraction of the nanocrystallites fo…
Fresnoite, Ba2TiOSi2O7, has been predicted structurally to be a new ferroelectric. Detection of both ac and dc dielectric hysteresis verifies the prediction. The spontaneous polarization Ps estimated from the hysteresis at 1.2 MV m−1 ac is ∼0.2 C m−2 at 295 K, comparable with the minimum Ps observed in one-dimensional…
Alignment control of mesogenic groups in a photocrosslinkable polymer liquid crystalline film was achieved by linearly polarized (LP) ultraviolet (UV) irradiation followed by heating. The alignment direction was parallel to the electric vector of the incident LPUV light and the tilt angle of the mesogenic groups could…
Variable temperature scanning-tunneling-microscopy/spectroscopy studies on single crystals and epitaxial thin films of hole-doped manganites, which show colossal magnetoresistance, have been done. We have investigated the variation of the density of states (DOS), at and near the Fermi energy ${(E}_{f}),$ as a function…
We report the variation of the structure and the electronic properties of amorphous nitrogenated carbon films (a-CH:Nx) prepared in dual electron cyclotron resonance-radio-frequency plasma from different mixtures of methane and nitrogen. Electron energy-loss spectroscopy, Auger electron spectroscopy, spectroscopic ell…
The transmission and reflection coefficients of a carbon nanotube with a scatterer are calculated in a tight-binding model. The result obtained in a k · p scheme is shown to be essentially valid, including the complete absence of back scattering for scatterers with range larger than the lattice constant, unless the st…