Materials Literature
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Abstract N-(4-Alkoxybenzylidene)-4-halogenoanilines have been synthesized, and the phase transitions determined using a differential scanning calorimeter and a polarizing microscope. Smectic and nematic phases have been observed for fluoro and chloro derivatives whereas bromo and iodo derivatives exhibit only a smecti…
The interpretation of the configurations 4 f N 6 s and 4 f N 5 d has been improved by using complete matrices for N = 6 and N = 8. Generalized constants which describe the evolution of the electrostatic parameters as a function of N have been fitted by the least-squares method, from 492 energy levels of second spectra…
Abstract The temperature dependence of the microwave per mittivity of PbHPO 4 is determined at 8.2, 9.6 and 37 GHz in the para‐ and ferroelectric phase. The data are not consistent with a Debye‐type relaxation. In addition the far‐infrared reflection spectra between 15 and 650 cm −1 are measured with radiation polariz…
Some questions of repassivation potential, ER, were considered by using a nut/nut crevice of Type 316 steel which is similar in design to the geometry of a real crevice. The first is the variation of ER with the extent of previous growth as has been confirmed in the case of ER against pit propagation. Cyclic polarizat…
Magnetic susceptibility measurements are reported for a series of tetranuclear copper (II) complexes [Cu4OX6L4](X = Br or Cl; L = Cl, Br, C5H5N, C5H5NO, tetramethylurea, or dimethyl sulphoxide). These data and literature data on other tetranuclear complexes describe a range of magnetic behaviour, varying from strong i…
The title complex crystallizes in the triclinic space group P with unit-cell dimensions a= 12.17(1), b= 13.28(1), c= 8.67(1)Å, α= 97.78(8)°, β= 89.93(8)°, γ= 98.93(8)°, and Z= 2. The structure has been solved from X-ray single-crystal counter data and refined by least-squares calculations to R= 0.07 for 1 689 signific…
Abstract A major drawback of mineral stability determinations by the solubility method has been that oftentimes years are required to reach equilibrium. Minimum equilibration times require that minimum amounts of solution be equilibrated with maximum amounts of mineral. Thus, about 10 ml of solution was displaced from…
Mating behavior and oviposition in the pycnogonid Pt-opallene longiceps (Bi'hm) were observed in the laboratory. The female collects the eggs laid and transfers them to the male. The male forms bracelet-like egg masses and cames them on its ovigerous legs until hatching. The processes of copulation and oviposition are…
Methods for preparing experimental animal tissues for the scanning electron microscope (SEM) have evolved from so many sources, with such lack of standardization that interpretation of the results is difficult, and inter-investigation comparisons usually impossible. To distinguish the surface changes inherent in any p…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSolid-state photooligomerization of an extended chiral bifunctional monomer, (+)-2,4:3,5-di-O-methylene-D-mannitol 1,6-di-trans-cinnamateJoel Bernstein, Bernard S. Green, and Miriam RejtoCite this: J. Am. Chem. Soc. 1980, 102, 1, 323–328Publication Date (Print):January 1, 19…
Abstract Titania gels were prepared by oxidation of precipitates of hydrous Ti III oxide obtained at different pH values from aqueous titanous chloride by the addition of ammonia. The gels were dried at 110–120°C (383–393 K) and their surface properties were characterised by nitrogen adsorption at 196°C (77 K). The ni…
The luminescence emission under X-ray and ultraviolet (UV) excitation of BaTiO3 crystals (obtained by different methods and with various amount of iron doping) has been obtained in a wide temperature range. The temperature dependence of the half-width, position of the maximum and emission intensity of the various band…
The crystal structure of a natural calcium heulandite (Ca)heu and a partially silver-exchanged heulandite (Ag,Ca)heu is reported. The monoclinic crystals, space group C2/m, have cell parameters a= 17.672(6), b= 17.930(6), c= 7.443(4)Å, β= 116.5(1)°, Z= 1, and formula Ca3.1Na1.1K0.1Al7.6Si28.5O72·24H2O (from electron m…
The variation of the periodicity along the $C$ axis (${N}^{\ensuremath{'}}C$) as a function of temperature in ${\mathrm{Fe}}_{9}$${\mathrm{S}}_{10}$, where ${N}^{\ensuremath{'}}$ varies between 5 and 1 over the range 300-600 K, has been investigated. The antiferromagnetic to ferrimagnetic ($\ensuremath{\lambda}$) phas…
Abstract A new detection configuration for the Scanning Electron Microscope (SEM) has been devised, which allows the imaging of the surfaces of a specimen in the open room, i.e., at atmospheric pressure. Such a device gives rise to a new microscope: the Atmospheric Scanning Electron Microscope (ASEM). In this configur…
The effect of preparation method, calcination temperature and sodium content on the dispersion of molybdenum on the surface of γ-Al2O3, as well as on the kind of molybdenum species formed thereon, has been studied using diffuse reflectance spectroscopy (d.r.s), X-ray powder analysis (X.r.), X-ray photoelectron spectro…
Primary cultures of rabbit corneal endothelial cells were labeled with proline and the medium proteins were fractionated by sedimentation through sucrose density gradients. A new collagen, endothelial cell (EC) collagen, was completely separated from type IV collagen without denaturation by this technique. Sodium dode…
We report magnetic susceptibility (χs) data from 2.6 to 300 K for ten quasi one-dimensional organic conductors, most of which obey the law χs = AT-α with α ≃ 0.7 below about 20 K. Results for irradiated TTF-TCNQ and other évidence indicate that such behaviour can occur for a small concentration of unpaired spins at th…
A measurement of the thermal conductivity and the specific heat of pure and iodine doped samples of polyacetylene (CH)x are presented here. The thermal conductivity of pure (CH)x is about 75 mW/cm . K at room temperature and decreases monotonically to 1.6 mW/cm . K at 25 K. The specific heat dependence with temperatur…
The paper reviews the existing experimental evidence for irradiation induced re-solution and also possible explanations for the mechanism. The importance of re-solution is considered with regard to intragranular bubbles and the accumulation of gas on grain boundaries. It is concluded that re-solution is most effective…