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。
The fracture process in ceramic materials upon impact loading is complex in nature. Most often, the brittle ceramic deforms inelastically due to microcracking under shock (compression) loading. At high-velocity impact, the shock generated microcracks rapidly open and extend under subsequent tension (due to the release…
We have demonstrated that single point diamond turning can be used to generate high optical quality finished surfaces on a new organic nonlinear crystal, L-arginine phosphate (LAP). The proper choice of cutting conditions can produce surfaces with <5-A rms local roughness. Local softening or melting near the cutting t…
We have measured inelastic-electron-scattering spectra of several hexagonal-boron-nitride samples with momentum transfer both in and out of the a-b plane and obtained the dielectric and optical constants from 0 to 60 eV. The low-q energy-loss spectrum with momentum in the plane is dominated by the \ensuremath{\pi}-ele…
An increase of the room-temperature band gap from 4.23 to 4.96 eV is observed in crystals of the superionic material yttria-stabilized cubic zirconia (YSZ) when the crystals are reduced either electrolytically or in a hydrogen atmosphere. The original absorption edge of 4.23 eV in unreduced YSZ can be accounted for by…
Our recently developed RISM integral equation theory of the structure and thermodynamics of homopolymer melts is generalized to polymer mixtures. The mean spherical approximation (MSA) closure to the generalized Ornstein–Zernike equations is employed, in conjunction with the neglect of explicit chain end effects and t…
It is known experimentally that Heusler alloys, Ni 2 MnGa and Co 2 NbSn undergo the cubic-to-tetragonal lattice transformation, in a ferromagnetic state and a paramagnetic one, respectively. We calculated electronic structures of Co 2 NbSn and Ni 2 MnGa for both cubic and tetragonal structures by KKR method. Comparing…
The rate of reaction for oxidation of CO over (210) and (111) single-crystal surfaces of platinum has been studied as a function of reactant pressures (PO2,PCO) and sample temperature (T), both experimentally and by computer simulation. Experimental results on both surfaces show regions with a steady high rate of reac…
A direct comparison of the infrared-active vibrational (IRAV) modes in heavily doped, lightly doped, and photoexcited trans-(CH${)}_{\mathrm{x}}$ is presented. The infrared absorption spectrum of heavily doped trans-(CH${)}_{\mathrm{x}}$ exhibits doping-induced IRAV modes and an onset of electronic absorption which ar…
Properties of one-dimensional quasiperiodic discrete Schr\"odinger equations are analyzed by means of a finite-size scaling of the spectrum and the wave function. The incommensurate Harper model, which has only one Fourier component in the potential, is analyzed as an example, and some quantitative results, which are…
The band structures of cubic ${\mathrm{Cu}}_{2}$O and monoclinic CuO crystals have been calculated by means of the first-principles orthogonalized linear combination of atomic orbitals method. Using the wave functions obtained, the frequency-dependent interband optical conductivities are also evaluated. The results sh…
Polycrystalline barium titanate that has been doped to give a positive temperature coefficient of resistance (PTCR) effect is an inhomogeneous material electrically. Analysis of ac impedance data using the complex impedance plane representation gives the dc resistance of PTCR ceramics. By additional use of the complex…
The dielectric relaxation of 1,2,4-butanetriol in its supercooled liquid state has been studied at pressures up to 1 GPa. The frequency of the applied field is varied within the range from 1 mHz to 10 MHz. The automated and computer controlled dielectric spectroscopy measuring system is presented in detail. It is foun…
Low resistance ohmic contacts were manufactured on a natural semiconducting diamond (type IIb), by implanting boron ions at a temperature of 200 degrees C. This was followed by annealing at 1200 degrees C and removal of the top ion-damaged layer by etching in a hot acids solution. The thin, highly doped surface which…
Li 2 B 4 O 7 activated with a Cu impurity exhibits the 'unique' characteristics of linear thermoluminescence (TL) effects, a rare feature very similar to that of LiF:Mg, Cu, P, another phosphor of this category. Its thermoluminescence is investigated for its trap distribution characteristics. The analysis, based on a…
The nature and production of x-rays diffraction effects structures, composition, properties and occurences of clay minerals sample preparation techniques for clay minerals sample preparation techniques for clay minerals identification of individual clay minerals and associated minerals identification of mixed layered…
Cross-sectional and plan-view transmission electron micrograph analysis of the structure of porous silicon reveals that the pore walls are also porous, yielding a large distribution of pore sizes for a given porous silicon sample. This infrastructure appears to be a universal morphological feature of porous silicon, i…
ABSTRACT Stress corrosion cracking (SCC) in nonmagnetic drill string components made of austenitic stainless steel alloys has been a long-standing industry-wide problem. Three currently available technologies, each capable of producing a zero frequency of SCC, are presented in this paper. The application of compressiv…
Abstract When applied as conformance treatments, foams are required to effectively reduce gas injectivities over prolonged periods of time. Frequently, this ability must be manifested in the presence of a residual oil saturation which often exerts a destabilizing effect on foam and the capacity to generate foam. In th…
The ability of algae and bacteria to accumulate heavy metals from the surrounding environment is a widely recognized phenomenon that has a number of important implications. This work reports on the development of a quantitative model that addresses the basic mechanisms inherent in many uptake processes. The model post…
We have previously reported on liposome formulations with reduced uptake by the reticuloendothelial system, prolonged circulation time, and enhanced accumulation in transplanted tumors. One of these formulations, consisting of hydrogenated phosphatidylinositol (HPI), hydrogenated phosphatidylcholine (HPC), and cholest…