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。
Tetramethylammonium tetrachlorozincate, {N(CH 3 ) 4 } 2 ZnCl 4 has been found to undergo successive phase transitions at about -112, -92, 3.3, 6.0 and 20°C and to show ferroelectricity along the a axis in the temperature range between 3.3 and 6.0°C.
The nature of Sb 2 O 5 , a matter of dispute to the present day, has now been elucidated by crystal structure analysis. The principles of coordination and connection accord with those of BNb 2 O 5 . This is the first such relationship between the pentoxide of a main group element and that of a subgroup element.
Abstract Depolymerization of poly‐ϵ‐caprolactam chips was carried out at low pressures (3–15 mm Hg) and elevated temperature (225°–270°C) in the presence of sodium hydroxide as catalyst. The effects of variation of amount of sodium hydroxide, time, temperature, and pressure on ϵ‐caprolactam yield were studied. With in…
A smoothing procedure is described which eliminates spurious details on crystallite-size distribution functions deduced from X-ray line profiles. It is based on a least-squares process with a stabilization scheme and is applied to composite specimens prepared by mixing known quantities of samples of nickel hydroxide,…
A multiple integral expansion of the Boltzmann superposition principle when applied to sinusoidal shear oscillations becomes σ(t)=γ0[G1′ sinωt+G1″ cosωt]+γ03[G3′ sinωt+H3′ sin3ωt+G3″ cosωt+H3″ cos3ωt]+γ05[0]. We have evaluated this constitutive equation with hollow cylinders of polycarbonate and polymethylmethacrylate…
The temperature variation of the separation of Shockley partials of single dissociated dislocations in Cu-6·44 at. % Al and Cu-13·43 at. % Al has been measured by means of in situ thermal cycling experiments in a high-voltage electron microscope; a weak-beam high-resolution imaging technique was used for the observati…
The intermetallic compound Fe 3 Sn 2 has been studied by Mossbauer spectroscopy and magnetisation measurements. This compound is ferromagnetic from approximately 220K to T c =657K. In this temperature range, the spin directions are close to or parallel to the c axis while at low temperature they are perpendicular to i…
Abstract The transition between the amorphous state and 3 crystalline modifications of poly(ε‐caprolactam) (polyamide‐6) has been investigated in Part 1 by IR spectroscopy. With these results as background the relation between heat of fusion Δ H * and specific volume v is now investigated as a function of crystallizat…
Abstract The hydrated form of tubular halloysite [halloysite (10 Å)] was observed by a conventional electron microscope equipped with an environmental cell (E.C.), by which the “natural” form was revealed without dehydration of the interlayer water. This study mainly reports the selected area electron diffraction (SAE…
The numerical solution of the Clausius-Mossotti problem for the permittivity of a suspension of perfectly conducting spheres in a cubic array is presented for sc, fcc, and bcc lattices. The results apply to electrical permittivity, magnetic permeability, electrical and thermal conductivity, and particle diffusivity. T…
The unmetamorphosed equivalents of the regionally metamorphosed clays and marls that make up the Alpine Liassic black shale formation consist of illite, irregular mixed-layer illite/montmorillonite, chlorite, kaolinite, quartz, calcite, and dolomite, with accessory feldspars and organic material. At higher grade, in t…
This investigation is concerned with the effect of chromium and molybdenum on the formation of the passive film of stainless steels, and its corrosion resistance to the chloride ion. The corrosion resistance to the chloride ion was estimated by the potential decay method and the measurement of the anodic polarization…
The crystal structures of the high pressure Ga(II) and Ga(III) forms of gallium were studied by single-crystal x-ray diffraction using a diamond anvil device. Ga(II) has a body-centered-cubic structure with a=5.951±0.005 Å and 12 atoms in the centered cell; Ga(III) has a body-centered-tetragonal cell with a=2.813±0.00…
The localization and synthesis of alphafoetoprotein (AFP) during mouse embryogenesis were studied by immunoperoxidase and by immunoprecipitation after radioactive labelling, using an antiserum prepared against AFP. AFP is first detectable in embryos on the 7th day of gestation (7th day embryos). In 7th and 8th day emb…
Abstract Reinforcement mechanisms of fiber‐glass reinforced plastics (FRP) under wet conditions are reviewed with emphasis on molecular structures of glass/matrix interfaces. Included are studies on glass surface, the glass/coupling agent interface, silane coupling agents on glass surfaces as well as in solution, the…
Abstract TlGaSe 2 kristallisiert monoklin mit a = 10,772(3) Å; b = 10,771(5) Å; c = 15,636(8) Å; β = 100,6(3)°; Z = 16; Raumgruppe Cc. Nach der Verfeinerung mit 1366 unabhängigen Reflexen ergab sich ein R‐Wert von R = 0,082 (MoKα‐Strahlung). Die Verbindung bildet ein Schichtengitter mit zwei Anionenschichten parallel…
Using the R-line fluorescence of trace Cr3+ in sintered Al2O3 as an example, a method of analysis is outlined for determining the residual microstress and macrostress in a polycrystalline aggregate. It uses the shift and broadening, induced by residual stress, of a line due to a transition in an atomic system dissolve…
A chemical-bond approach reveals the possibility of several unusual bonding configurations that have relatively low energy in materials with lone-pair valence electrons. Valence-alternation pairs (V.A.P.) are the lowest energy charged defects. The interconversion between positive and negative centres is described in d…
Using muffin-tin orbitals and the atomic-sphere approximation, we have studied the band structures of Chevrel-phase molybdenum chalcogenides, ${M}_{m}{\mathrm{Mo}}_{6}{X}_{8\ensuremath{-}x}$. Generally, these compounds exist for a broad variety of elements, $M=\mathrm{Pb},\mathrm{Sn},\mathrm{Ag},\mathrm{Cu}$ and $X=\m…
The no-reflow phenomenon was studied following reconstitution of blood flow by microvascular anastomosis in an ischemic and denervated free epigastric flap in the rabbit. Microscopic, histological, angiographic, and hematological studies demonstrated the progressive nature of this obstruction to the peripheral blood f…