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。
Thermal cycling effects in a Cu-13.7 Al-4.0 Ni (mass%) alloy have been studied by optical and electron microscopy observations and X-ray diffraction. Transformation temperatures, Ms and Af, decrease gradually with increasing thermal cycles, the magnitude of the decrease reaching about 40 K after 10000 cycles. Martensi…
It has been experimentally demonstrated that micrometersized particles of graphite deposited on the surface of copper and niobium electrodes can promote the field emission of electrons in the range of 5-20 MV ·m-1. From measurements of the current-voltage characteristic, electron spectrum, and emission image of such s…
Tetraphenylporphinatoiron (III) catalyzed the reductive activation of molecular oxygen in the presence of NaBH4 and Me4NOH. Several olefins were oxidized with this system and oxidized products were isolated in high yields.
A chitosan film was newly prepared from the liquid crystal solution. The unit cell parameters of crystal were determined: a=8.67 Å, b=10.24 Å (fiber axis), c=8.92 Å, and β=92.6°. These parameters accorded with those of the (1-3) crystal reported previously within an experimental error. In addition, the packing of mole…
We summarize the current status of our studies of the macroscopic linear mechanical properties of nematic liquid crystals formed from solutions of rigid or semirigid rod-like polymers. The polymer system we have studied is a racemic mixture of poly(benzyl glutamate) dissolved in a mixture of dioxane and methylene chlo…
The Landau-de Gennes free energy expansion coefficients for nematic polymers are evaluated on the basis of a molecular-statistical model. It is proved that the obtained expansion provides a reliable qualitative description of the phase transition to the nematic state for polymers with arbitrary molecular length and ri…
The general physical features and a mathematical description of spectral diffusion in glasses at low temperatures is considered. The condition is found for when spectral diffusion can be treated as a Markovian process. The physical reason for the Lorenzian form of a two-level system spectral line shape is considered.…
Abstract A neutron diffraction study at 20 K of a single crystal of scolecite (CaAl 2 Si 3 O 10 · 3H 2 O, a = 6.516(2), b = 18.948(3), c = 9.761(1) Å, β = 108.98(1)°; Cc , Z = 4, D c = 2.28 g/cm 3 ) utilized 2109 diffraction intensities from the Brookhaven National Laboratory High Flux Beam Reactor ( λ = 1.0505(1) Å,…
Abstract The mechanism of cellulose alkalization in isopropyl alcohol (IPA)–water–sodium hydroxide system was studied from the viewpoint of the selective distribution of sodium hydroxide between cellulose and the medium, and of the lattice transition of cellulose. A mixture of IPA, water, and sodium hydroxide spontane…
Evidence is presented to support the view that the surface of a fascicle reflects the wave pattern of its constituent collagen fibrils. The wave pattern shows considerable variation within and between fascicles. Smooth continuous phase shifts in crimp angles and crimp lengths across the width and along the length of a…
The Marshall Procedure as applied to design and control of asphalt mixtures used in the Department of Defense evolved during the period from World War II to the late 1950's. Motivation for its development came from a need for a mix design procedure to proportion aggregate and asphalt binder to sustain increasing wheel…
The Structure of a new bis-cyclotribenzyl cavitand, (2), forming an internal 1 : 1 Complex (‘cavitate’) with dichloromethane, has been determined by single X-ray crystallography.
Abstract A number of polysaccharides of the starch type, including maltodextrins and cyclodextrins and some other well‐known polysaccharides have been oxidized by periodate/chlorite (two‐step method) or hypochlorite (one‐step method), yielding ring‐opened polycarboxylates. The oxidation products from the starch type s…
Substitution of tetraphenylporphyrinatomanganese(III) complexes on the peripheral phenyl groups makes these compounds suitable as catalysts for the epoxidation of terminal olefins with mono-oxygen donors such as sodium or lithium hypochlorite and potassium hydrogen peroxomonosulphate in a biphasic system.
Single-crystal e.s.r. spectra of u.v.-irradiated octakis(methylammonium) decamolybdate(VI) dihydrate, [NH3Me]8[Mo8O26(MoO4)2]·2H2O, show the formation of two distinct localized MoVO5(OH) sites, resulting from a hydrogen-bonding proton transfer from [NH3Me]+ to a bridging oxygen atom in the anion. Analysis of the e.s.r…
Dans cet article sont donnes 150 parametres de solubilite de matieres cosmetiques ainsi que les methodes pour leur calcul et un programme d'ordinateur
Résumé. 2014 Les variations en fonction de la température des invariants du paramètre d’ordre sont mesurées dans les phases nématiques uniaxes et biaxes de différents mélanges de laurate de potassium, 1-decanol, D2O. Elles montrent que les transitions de phase nématique uniaxe-biaxe sont du second ordre et de champ mo…
The relationship between low-molar-mass or monomeric liquid crystals and polymeric liquid crystals is explored by examining the historical development of experimental and theoretical aspects of the latter materials. Polymeric liquid crystals are initially contrasted with conventional, non-mesogenic, flexible polymer c…
Aqueuous solutions of copper(I) iodide, potassium iodide, and the crown ether from unexpectedly different and novel structure: [Cu4I6][Cu8I13]K7(12-crown-4)6 with two different clusters per asymmetric, unit and polymeric modifications, [Cu4I6]K2(15-crown-5)2, and [Cu3I4]K(dibenzo-24-crown-8) depending upon identity of…
Hydrogen attack (HA) is a degradation process occurring in steel exposed to hot, high-pressure hydrogen. It is caused by the nucleation, growth, and ultimate link-up into fissures of small methane bubbles – primarily on grain boundaries. The location and growth kinetics of the submicrometre bubbles during the incubati…