Materials Literature
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Acetoacetic esters and pentane-2,4-dione undergo unusual Michael reactions with β-nitrostyrene in methanolsodium methoxide to formthe (2R,3R,2′S,3′S)-bis-(4-acy1-2,3-dihydro-5-methyl-3-phenyl-2)-furylhydroxylamines (5) in high yields. The normal adducts (6) are intermediates in these reactions. Acetylation of compound…
It was found that the corrosion rate of CuNi10Fel·4 in aerated sea water at 40 and 50°c was lower than that at the lower sea water temperatures of 10–30°c. This was mainly due to the quick formation of a protective layer of corrosion products at the higher temperatures. Moreover, the protectiveness of these layers app…
DC partial discharge (PD) (corona) testing is performed using a multichannel analyzer for pulse storing, and data is collected during increase of voltage and at quiescent voltage levels. Thus high voltage ceramic disk capacitors were evaluated by obtaining PD data interspersed during an accelarated life test. Increase…
The corrosion resistance of iron in acid and neutral chloride solutions has been investigated as a function of the purity of iron. Five kinds of iron having residual resistivity ratios, RRRH,4.2K, of 80, 150, 800, 1500 and 6000 were used as specimens. The former three with RRRH,4.2K 80, 150 and 800 were commercially a…
This paper demonstrates that the color of natural yellow fluorites is due to an O−3 molecule ion incorporated into the lattice. The center has several equilibrium positions. A detailed EPR and ENDOR study of this center is presented and the motional effects observed in the EPR spectrum are analyzed.
Suzukiite, Ba2V4+2[O2|Si4O12], orthorhombic, Amam or Amam2, a=7.089(2), b=15.261(2), c=5.364(1)Å, Z=2, is a new mineral corresponding to the barium analogue of haradaite, Sr2V4+2[O2|Si4O12].The electron microprobe analysis gave : BaO 38.38, SrO 3.21, VO2 23.56, TiO2 0.20, SiO2 33.59, total 98.94%, yielding the empiric…
After a short introduction, the general characteristics of liquid crystals are reviewed, the three main classes of thermotropic liquid crystals are described and the concept of order parameters introduced. The phase behaviour of thermotropic liquid crystals is considered in some detail and the continuum theory, descri…
Differences between grain boundary sliding with crystal slip and that without it are investigated by the use of orientation controlled cadmium bicrystals.Without crystal slip, the rate of grain boundary sliding varied in proportion to applied stress and was controlled by grain boundary diffusion. With crystal slip, th…
With a view to examining the embrittlement behavior of Zircaloy due to inner surface oxidation occurring in an LWR loss-of-coolant accident, ring-like Zircaloy-4 cladding specimens were heated at the isothermal oxidation temperature ranging 890~1,194°C in an environment of stagnant steam, which simulated the atmospher…
The field induced cholesteric-nematic transition is discussed for the case where the helical axis is parallel to the plane of the sample. Approximate solutions for the critical field are presented for both homeotropic and planar boundary conditions.
Experiments with copper in acidified dichromate solutions have shown that a magnetic field can enhance the rate of diffusion-controlled corrosion. Care should be taken in chemical and electrochemical industries to keep hardware susceptible to corrosion away from the domain of magnetic fields.
Four 18-oxygenated pregnane-type steroids ; 18, 20-epoxypregn-5-en-3β-ol acetate (III), 18, 20-epoxy-isolineolon cyclic sulfite (VIII), 18, 20-epoxy-deacyl condurangogenin C (XVIII), and 18, 20-epoxy-20-epideacyl condurangogenin C (XXI) were synthesized, and their structures were established by chemical and spectral s…
Spherically agglomerated crystals of aminophylline were prepared directly during reaction in liquid by the "spherical crystallization" technique. Agitation of a mixture of chloroform, ethanol (or methanol) and water containing ethylenediamine and theophylline yielded spherically agglomerated crystals, the size of whic…
Experimental values are reported for the splay/twist viscoelastic ratios of OHMBBA in the nematic region as a function of temperature. In the experiments the homodyne self-beat technique was used to detect noise intensity spectra of laser light scattered by the nematic liquid crystal. The measured rotational viscosity…
This paper is concerned with a method for calculating the thermal-stress distribution in a nonhomogeneous medium whose shear modulus and coefficient of thermal expansion are assumed to be functions of z. The solution of the problem is determined by using displacement functions. A solution is then derived for the therm…
A generalized maximum determinant rule is shown to be equivalent to maximizing the integral, of the logarithm of the electron density, i.e. equivalent to the 'maximum entropy method' (MEM) of image reconstruction. Relations between the structure factors and the Fourier coefficients of the reciprocal of the electron de…
Riverside nontronite, a candidate for the major mineral in the Martian fines, becomes both redder and darker upon shock loading between 180 and 300 kbar. The change from olive‐yellow (2.5 Y 6/6) to strong brown (7.5 YR 4/6) in the 300‐kbar sample brackets the range of color observed at the Viking lander sites. Optical…
Some derivatives of the homologous series of 4-cyanophenyl-3-methyl-4-(4-n-alkoxycinnamoyloxy) benzoates and of 4-cyanophenyl-4-(4-n-alkoxy-α-methyl cinnamoyloxy) benzoates have been synthesises. The higher homologs of these series exhibit reentrant nematic phases at atmospheric pressure.
The synthesis of LaCrO3 from the mixture of chromium hydroxide and La2O3 was studied under hydrothermal conditions and in air. LaCrO3 was directly prepared under hydrothermal conditions of above 400°C under 100MPa H2O pressure in contrast to the formation of LaCrO3 via La2CrO6 above 700°C in air. LaCrO3 synthesized un…
Abstract The chemical and physical characteristics of a ruthenium catalyst used in the hydrogenation of benzene to cyclohexene has been investigated. The active catalyst consists of metallic ruthenium obtained by hydrogen reduction of the precursor suspended in the alkaline aqueous phase. The precursor consists of hyd…