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 key features leading to low-energy grain boundaries in metals are discussed by reference to computer-simulated structures and geometrical analysis in terms of atom packing. Low energy is found to be associated with boundary structures consisting of relatively dense packing, and this can in turn be expressed in ter…
An experiment was carried out to investigate the preparation condition of anisotropic Ca system ferrite magnets with optimum magnetic and physical properties. Compositions were chosen according to the formula (CaO.nFe2O3)100-x(La2O3)x, wherexwas varied between 0 and 4.0, and n between 5.5 and 6.25. The optimum conditi…
A series of poly(alpha-amino acid)s with controlled chemical variations were investigated in order to assess the effect of different chemical moieties upon arterial thrombosis. The gross implant surface properties ranged from hydrophobic to hydrophilic ionic and nonionic. The materials were tested by implantation with…
Abstract Water‐insoluble carboxyl‐containing starches were prepared by grafting acrylonitrile onto a highly crosslinked starch followed by base saponification to convert nitrile groups into a mixture of carboxamide and carboxylate groups. Ceric ammonium nitrate or ferrous sulfate–hydrogen peroxide was used to initiate…
Abstract Effect of the concentration of four types of carbon black, namely, HAF, FEF, ISAF and GPF, on the electrical conductivity of SBR (1502) was studied. The anomalous behavior of conductivity [σ min in σ( T ) curves] becomes more pronounced as we approach a characteristic value of carbon concentration, F 0 , at w…
The low-temperature phases of the alkali hyperoxides K${\mathrm{O}}_{2}$, Rb${\mathrm{O}}_{2}$, and Cs${\mathrm{O}}_{2}$ have been investigated by means of electron paramagnetic resonance (EPR) and antiferromagnetic resonance (AFMR). The knowledge of their structural and magnetic properties could be enlarged substanti…
Spark-generated bubble behavior was observed in an unbounded fluid and in the vicinity of a wall, both for water and a polymer solution. The formation of the re-entering jet close to the wall is retarded in the presence of polymer additives.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTProton and carbon-13 nuclear magnetic resonance spectroscopy studies of aluminum halide-alkylpyridinium halide molten salts and their benzene solutionsJ. Robinson, R. C. Bugle, H. L. Chum, D. Koran, and R. A. OsteryoungCite this: J. Am. Chem. Soc. 1979, 101, 14, 3776–3779Pub…
The measurements of the anisotropy of the refractive index have been made for heptyl-cyanobiphenyl (7CB) at the surface as well as in the bulk by the interferometric method. Using these data, order parameters S̄ at the surface and S in the bulk were calculated. The results show that S̄ is slightly larger than S in the…
Using 22 Na as a radiotracer, mobilities of sodium ions in various types of SiO 2 glasses were measured and found to depend on the OH content in the silica network. Increasing OH content in SiO 2 considerably reduces the Na mobility. The effect of immobilization of Na is discussed in terms of an interaction between hy…
Abstract Sample horizons of an acid Inceptisol from New York, an Oxisol from Brazil, and an aluminum‐peat complex containing 1 mole of Al per mole of peat carboxyl groups were extracted with 1 N KCl and 1 N LaCl 3 . For all three materials, LaCl 3 extracted significantly more Al. The quantity of Al extracted expressed…
Diffraction gratings are used in many optical systems as beam splitters. In these applications the diffraction grating must (1) have high diffraction efficiency and (2) produce uniform intensities in the central block of diffracted beams. High diffraction efficiency is attained by making the grating a phase grating. I…
Relative cathodoluminescence quantum intensity measurements made on crystals containing a series of concentrations of each of the ions Ce 3+ , Eu 3+ , Tb 3+ , and Gd 3+ are reported as a function of temperature. For the first three of these activator ions the CL intensity increases with temperature, although the effic…
We report here the dependence on hydrostatic pressure up to 2.79 kbars of the two structures associated with the A 1 and A 2 transitions in the reflectivity spectra of graphite measured at room temperature in the photon energy range from 0.655 to 1.125 eV. By considering explicitly the effect of the trigonal warping u…
Abstract Activities of various bleaching earths for removal of β‐carotene from acetone solution were found to be in the decreasing order tonsil, fuller's earth, silica, and kaolin. Experimental evidence indicated that except for silica, in addition to physical adsorption, processes involving chemisorption and subseque…
This paper describes a statistical model for the strength of twisted bundles of stiff fibers. The model evolves from the classic model for bundle strength and is most applicable for short bundles with low friction between filaments; however, the model is believed to yield insight into the strength behavior of longer y…
Conformations of n-alkane molecules in the liquid state have been studied as a function of temperature and pressure using Raman scattering. Observations of conformationally sensitive Raman bands in hexane, heptane, octane, and hexadecane reveal no sign of the pressure-induced effects in polyethylene. Instead the Raman…
The author reviews several important aspects of the problem of one-dimensional metals, including a discussion of their instability, a survey of various materials which are more or less nearly one-dimensional, a fairly detailed treatment of the elementary excitations of charge density waves and a discussion of their el…
The skin relief influences the exterior aspect of the skin which is very sensitive to aging. It could also be related to the mechanical properties and structure of both dermis and stratum corneum. Consequently, quantitative measurement of the skin surface roughness would seem most useful, as it would permit a quantifi…
The effect known as ferroelectricity arises when forces between polarizable ions in a solid produce a spontaneous displacement of these ions which results in a lattice polarization below some characteristic (Curie) temperature. Fluctuations in this polarization may be thermally induced as in the case of classical ferr…