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 common observation of cellular substructure ((1 ÷ 10 -2 )mm) at the sea-ice-ocean interface is explained by modelling the natural solidification of seawater as that of a dilute H 2 O-NaCl solution. Linear and nonlinear perturbation theories reveal that the one-dimensional planar steady state is morphologically uns…
Raman-scattering experiments have been carried out on stage-2 silver-intercalated ${\mathrm{TiS}}_{2}$ single crystals. Below a transition temperature near 300 K, the intercalated silver atoms become ordered in a structure that produces a \ensuremath{\surd}3a\ifmmode\times\else\texttimes\fi{} \ensuremath{\surd}3a\ifmm…
Abstract The degrees of swelling of rigid aromatic polyamide networks in various solvents, nonsolvents, and solvent mixtures were used to determine their solubility parameters. This was made possible because of the amorphous nature of the rigid networks and the low levels of intersegmental H‐bonding. The solubility pa…
Abstract The effect of low dose (1–20 Mrad) γ‐irradiation on five fluoropolymers (PVF, PVDF, ETFE, FEP, PFA), differing in fluorine content and chain structure, was studied. The radiation effect, reflected by changes in thermal and mechanical properties, as well as NaOH etched surface morphology, was investigated. The…
We present the results of a study of solid–fluid phase equilibria in systems of hard dumbbells for three values of the dumbbell bond length. Monte Carlo simulations were used to calculate the equation of state and Helmholtz free energy. Four orientationally ordered solid phases have been considered—the α-N2 structure…
We demonstrate that ${\mathrm{CdS}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Se}}_{\mathit{x}}$ nanocrystals embedded in glass suffer compressive strain which increases as the crystallite radius decreases. A model based on the dependence of the cluster surface free energy on the surface-to-volume ratio explains…
The optical spectra of actinide ions in the compound AnCl3 and doped into single-crystal LaCl3 were interpreted in terms of transitions within 5fN configurations. Energy-level calculations were carried out using an effective-operator Hamiltonian, the parameters of which were determined by fitting experimental data. At…
Small unilamellar vesicles (SUVs), consisting of highly purified distearoyl phosphatidylcholine and cholesterol (2:1 mol ratio) selectively increased the delivery of entrapped daunorubicin to solid tumors in vivo. When measured against free drug, SUV-entrapped daunorubicin produced a nearly 10-fold increase in tumor u…
Electronic structure and energetics of (0001) and (11\ifmmode\bar\else\textasciimacron\fi{}02) surfaces of sapphire, \ensuremath{\alpha}-${\mathrm{Al}}_{2}$${\mathrm{O}}_{3}$, were calculated using the self-consistent-field discrete variational (DV) method in the local-density framework. Clusters of a size of 70--120…
We show that low-temperature (230--390 \ifmmode^\circ\else\textdegree\fi{}C) desorption of hydrogen from 0.1 \ensuremath{\Omega} cm p-type porous Si structures leads to a redshift and gradual disappearance of the photoliminescence (PL). Furthermore, no blueshifting of the PL peaks is apparent with pore-widening treatm…
High-porosity porous silicon, after electrochemical oxidation, is a stable and highly reproducible luminescent material with a luminescence quantum efficiency as high as 3% at room temperature. Luminescence decay rates as long as several hundreds of microseconds show that radiative and nonradiative processes both have…
We present a detailed method to construct uniform meshes for fast Fourier transforms in electronic-structure calculations. We show that a drastic reduction in the mesh size can be frequently achieved by using an unconventional set of primitive lattice vectors. The same method can be applied also to obtain optimum sets…
The optical propagation in linear tapered waveguides is studied using both the beam propagation method as a non-modal technique and for local normal mode analysis. The comparison between the results obtained by the two techniques gives a good physical understanding of the transient behaviour of the optical field in th…
The excess charge relaxation in electret structures based on Teflon-FEP films, particularly the charge behaviour in the region of polymer-metal contact, has been investigated. Measurements were made using both the standard electret techniques and a special experimental method, based on observation of the partial recov…
In an attempt to produce polymeric pyroelectric Langmuir-Blodgett films, three derivatives of a hexadec-1-ene-maleic anhydride alternating polymer and two poly-(vinyl pyridine) derivatives have been deposited as alternate-layer films using a two-compartment trough. 1-Docosylamine and 22-tricosenoic acid were also alte…
A surface having a spatial gradient in its surface free energy was capable of causing drops of water placed on it to move uphill. This motion was the result of an imbalance in the forces due to surface tension acting on the liquid-solid contact line on the two opposite sides ("uphill" or "downhill") of the drop. The r…
The crystal structures and site-populations of 12 richterites have been refined to R indices of 1-2% using single-crystal MoKα X-ray diffraction data. Potassium-fluor-richterites from lamproites are characterized by [4] (Si+Al) sums less than 8.0 apfu (atoms per formula unit), suggesting the presence of other isomorph…
Zinc ferrite (ZnFe 2 O 4 ) has the cubic spinel structure with an (approximately) normal cation distribution. It was synthesised by direct reaction of the oxides at 800 ° C, and also by using a sodium tungstate flux with excess ZnO. Lattice parameters (a o ) of samples from both syntheses were emasured at room tempera…
The role of the attractive force in self-diffusion of atoms in a Lennard-Jones fluid is explored through molecular dynamics simulation. Expressions for the self-diffusion coefficient in terms of the memory function and the random force autocorrelation function are used to develop simple approximations which separate t…
Separable binary-phase array illuminators for fan-out up to 1024 x 1024 and ~65% two-dimensional efficiency are designed by simulated annealing with constraints for maximizing the minimum feature size. A new nonseparable trapezoidal coding technique is introduced and applied to design high-efficiency (~75%-80%) array…