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 anomalous behaviour of chalcogenide-glass switches, in the thin-film limit, is incorporated into the electrothermal switching model by taking account of both temperature and field dependences of the electrical conductivity. Calculations of the critical field as a function of temperature and thickness are compared…
Abstract The chain‐scission reaction which occurs in copolymers of styrene and acrylonitrile has been studied at temperatures of 262, 252, and 240°C. Under these conditions volatilization is negligible, and chain scission can be studied in virtual isolation. At 262°C three kinds of chain scission are discernible, name…
x-ray line broadening techniques have been used to determine both a - and c -direction crystallite sizes for a range of pyrolytic graphite samples whose effective formation temperature lay between 2330 and 3020°C. x-ray line profiles were analysed using the variance method. It is shown that if the proper allowance is…
Summary The‘precipitated‐calcium/precipitated‐phosphorus’ mole ratio approached a limiting value of 1 as the amount of phosphate, added to a suspension of calcareous soil in 0·01m CaC1 2 , was increased, indicating the precipitation of dicalcium phosphate. The phosphate and lime potentials provided further evidence th…
The moisture responses of plain jersey and 1 X 1 rib fabrics constructed from synthetic fiber-cotton blend yarns have been studied. The fabric responses include water vapor transmission, moisture imbibition, moisture regain, and air permeability. Measurements of the fabric strength and shrinkage are also reported. The…
ABSTRACT Native and cross-linked rat tail tendon collagen was irradiated with high energy electrons up to a maximum dose of 100 × 104 J kg − 1 (100 Mrd). Fibres irradiated dry showed greater damage when examined in the electron microscope using negative staining techniques than those irradiated wet. Cross-linking with…
Electron paramagnetic resonance (EPR) provides a sensitive tool by which microscopic bond rupture can be monitored simultaneously with observations of macroscopic deformation and failure. Past techniques for studying fracture in semicrystalline polymers have been extended to investigate degradation of unfilled ruber i…
Summary Many of the oxides and chalcogenides formed by the 3d transition metals and 4f rare-earth metals are antiferro-, ferri-and ferromagnetic semiconductors. In this review, several theoretical aspects of these materials are discussed, including electron correlation in narrow bands and the formation of electrostati…
The natural frequency of a spherical gas-filled bubble oscillating in a viscous compressible liquid is derived. Surface tension is also included in this solution, but gravity, gas diffusion and thermal conduction are neglected. The solutions of Minneart Richardson, Neppiras and Noltingk, Hirose and Okuyama, and Hought…
Summary Glass-ceramics based on the mineral cordierite have good mechanical and thermal properties. They can be easily prepared from glasses whose compositions lie in the primary phase field of cordierite on the 5 % CaO plane of the CaO-MgO-SiO 2 -Al 2 O 3 system. For uniform crystallization in the bulk, addition of a…
Abstract Polypropylene film was biaxially stretched in one step in air at 140°C or 152°C, and the deformation was studied optically. A linear relation held between Δ n ss and v A −½ for v A > 10, at both temperatures, where Δ n ss is the birefringence with respect to the normal to the film and v A is the degree of…
Abstract Soils sampled for laboratory characterization in Pennsylvania were separated into those profiles with fragipans and those without fragipans to determine statistically the soil properties consistently related to fragipan occurrence. Fragipans occurred in the following five parent material groups: aeolium, fluv…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPoly(2,6-diaryl-1,4-phenylene oxides)A. S. Hay and R. F. ClarkCite this: Macromolecules 1970, 3, 5, 533–535Publication Date (Print):September 1, 1970Publication History Published online1 May 2002Published inissue 1 September 1970https://pubs.acs.org/doi/10.1021/ma60017a012ht…
Production of sulphides of iron or of tin inside tinplate cans filled with sulphur-containing foodstuffs may cause stains which, although harmless, are a source of complaint from consumers. The formation of iron sulphide is widelythought to be a conversion by H2S or HS-ions of a preliminary Iron corrosion product. Evi…
Summary The application of classical nucleation theory to the initiation of crystal growth in glasses is discussed. Its application to experimental results obtained for the rate of nucleation in three types of glass, one showing nucleation separately from crystal growth, another showing simultaneous nucleation and gro…
The structure proposed for lead sesquioxide by Byström (1947) is incorrect. The space group found in the present work is P21/a with four Pb2O3 in the unit cell; the unit-cell dimensions are: a = 7.814, b = 5.625, c = 8.466 Å (all ± 0.003 Å); β = 124°48′ ± 5′. The structure has been determined by means of X-ray and neu…
Barium ferrite (Ba.0.6Fe2O3) platelets of approximately\frac{1}{2}\mum diameter and with intrinsic coercive force of about 5000 Oe were crystallized from a glass phase. To study the nature of the defects and their influence on the magnetic properties, the crystailized glass was plastically deformed by applying a press…
Abstract The processes of energy dissipation in polymeric foams are discussed. Theoretical considerations and experimental results show that impact behavior of foams with a rate independent modulus can accurately be predicted by Instron data.
The phenomenon, solid cadmium embrittlement, was identified and studied in the titanium alloys Ti-6Al-4V and Ti-8Al-1Mo-1V using cadmium coated tensile specimens and residual stress specimens. The conditions necessary for this phenomenon were found to be tensile stress and intimate contact between the cadmium and tita…
During measurement of preferred crystallographic orientation with the Schulz x-ray diffraction technique, several factors can cause defocusing. Earlier investigations showed that tilt of the specimen in Φ, the angle between the normal to the sample surface and the normal to the diffracting plane, is the most severe li…