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。
A structural model is proposed to account fully for observed x-ray scattering by certain nematic mesophases above their transition to smectic-C phases. In an external magnetic field, the constituent molecules tend to align into nearly periodic parallel chains that give rise to disc-like intensity distributions along t…
The optical principles of the Zeiss OPMI 1, 6-S, and 7 P/H operating microscopes are discussed, along with standard and fiberoptic illumination systems and the range of currently available support systems.
Diffusion couple experiments on the carbon diffusion in austenitic Fe‐Si‐C alloys at temperatures between 950 to 1150°C. Influence of the Si‐content in the range 1 to 6 wtpct Si and of the carbon content on the carbon diffusivity. Discussion of the decrease in diffusivity caused by Si. Method for computer evaluation o…
Abstract Experiments have been carried out to investigate the effect of equibiaxial orientation on the thermal conductivity of a series of natural rubber compounds. The conductivity was measured normal to the direction of stretch. The main effect has been explained quantitatively and an equation obtained which relates…
We have measured the optical absorption characteristics of copper oxide single crystals in the range from 1.1 to 2.0 eV. The crystals were annealed at various oxygen pressures at high temperatures and quenched to room temperature. A major, broad, previously unknown absorption peak was found at 1.6 eV which we relate t…
Abstract When certain substances, notably waxes, are incorporated into rubber during vulcanization, the surface of the vulcanized rubber may subsequently become covered by a film of the substance diffusing out. This phenomenon, known as blooming, depends on the substance being soluble at the vulcanization temperature…
Abstract The responses of a polymer flame to changes of specimen diameter, ignition position, and stability of the burning surface were determined. These extrinsic flame parameters restricted the transport of oxygen from the environment to the burning surface. With increasing restriction the oxygen demand from the env…
Experimental results are presented for impact of two parallel plates of 6061-T6 Aluminum, skewed at an angle of 26.6° from the axis of the projectile. A transverse displacement interferometer (TDI) [1] with a 200 lines/mm grating is used to monitor the transverse motion of the rear surface of the aluminum target plate…
Luminescence of is six times as bright as that of under 365 nm light excitation at room temperature, but it suffers from thermal quenching at higher temperatures. The quenching is mainly caused by non‐radiative relaxation from the emitting states. Energy diffusion among the lowest excited states, , to sinks is a main…
Abstract Fourier transform infrared spectroscopy has been used in conjunction with differential scanning calorimetric measurements to investigate the nature of molecular degradation and its effect on the phase transition temperatures in irradiated polytetrafluoroethylene (PTFE). Both the 19 and 30°C transitions are ob…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSpin-state isomerism of tris(2-picolylamine)iron(II). The diiodide and the hydrated dichlorideBradley A. Katz and Charles E. StrouseCite this: Inorg. Chem. 1980, 19, 3, 658–665Publication Date (Print):March 1, 1980Publication History Published online1 May 2002Published iniss…
The crystal structure of the high-temperature form of K2SO 4 was redetermined from three-dimensional X-ray diffractometer data at 1073 K and refined to an R value of 0.086 for 66 observed reflexions. The structure belongs to the hexagonal space group P63/mmc, with a = 5.947 (2), c = 8.375 (3) A, Z = 2, and D x = 2.26…
Abstract The crystal structures of the α and β forms of Dl-methionine have been refined by block-diagonal least-squares calculations using three-dimensional X-ray data to R=0.118 and 0.088 respectively. The structures of both the forms are essentially the same as those previously reported by Mathieson (Acta Crystallog…
Spatial (radial and longitudinal) yield spectra for electron energy degradation in molecular nitrogen gas for 25‐eV to 10‐keV incident electrons have been generated by using a Monte Carlo technique. These spatial yield spectra associated with the electron degradation process can be employed to calculate a ‘yield’ for…
On the basis of different surface treatments of a Type 316 stainless steel, results of protective film composition as obtained by Auger electron spectroscopy (AES) are related to resistance to initiation of crevice corrosion. The nickel content of the protective film was similar after all treatments, whereas the chrom…
Abstract A recent, corrected thermodynamic equation for the Gapon cation exchange selectivity coefficient produces a relation between the exchangeable sodium ratio (ESR) and the sodium adsorption ratio (SAR) that is indistinguishable from the widely used, empirical ESR‐SAR relation when SAR ≤ 40. In this sense, the th…
Thermal changes occurring during the setting of restorative materials have been measured accurately using a differential scanning calorimeter. The results were used to evaluate setting characteristics. The heat of reaction and rate of heat output may be significant in determining thermal damage to the pulp. The heat c…
A measurement of electric current is made on polypyromellitimide films of 25 µm thickness at temperatures of 120-180°C and electric fields 4-500 kV/cm over a time range of 10-3600 s. Since the low field conduction has been confirmed to be ionic, an attempt is made to fit the field-current plot to the theoretical curve…
SUMMARY Recent developments in the application of the SEM to semiconductor assessment are described. Formulae are presented for the calculation of the mean carrier density injected by the electron beam. A procedure for the correction of diffusion length measurements for surface recombination is outlined. Measured diff…
Abstract Potentiometric titration and ion adsorption data were analyzed according to theory which treats soils as mixtures of permanent and variable charge minerals. Evidence of permanent positive charge was found in a Spodosol and two Oxisols. Surface areas calculated from negative ion adsorption below and above the…