Preliminary results on dosimetric properties op MgB4O7:Dy
The thermoluminescent properties of magnesium borate, a new tissue equivalent material, have been stu died.
Materials Literature
文献浏览
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。
Statics and dynamics near the nematic-columnar phase transition in liquid crystals
A Landau-Ginzburg Hamiltonian describing a liquid crystal in the nematic phase near the nematic-columnar phase transition is used to find the renormalized nematic elastic constants and viscosities. The elastic constants, with the exception of the bend elastic constant, are found to be enhanced by order parameter fluct…
Intermediates in thermal decomposition of nickel(II) complexes: The crystal structures of Ni(SCN)2(NH3)2and Ni(SCN)2
Ni(SCN) 2 (NH 3 ) 2 and Ni(SCN) 2 are stable intermediates in the course of the thermal decomposition reaction Ni(SCN) 2 (NH 3 ) 4 → NiS 2 . Ni(SCN) 2 (NH 3 ) 2 crystallizes in the monoclinic space group C 2/ m with a = 8.698(5), b = 7.991(4), c = 5.619(3) Å, β = 105.91(9)°, Z = 2, D x = 1.85g cm −3 . The crystal data…
Texture Control of Zircaloy Tubing During Tube Reduction
Seven batches of Zircaloy-2 tubing with widely different textures were processed from tube shells of the same size, by different reduction routes using pilger and 3-roll mills. Based on the texture data of these tubes, the texture control of Zircaloy tubing, the texture gradient across the wall, and the texture change…
Development and Application of the Rolling Contact Fatigue Test Rig
The rolling contact (RC) fatigue test rig was developed specifically for rapid and inexpensive evaluation of materials and processes for rolling element bearing applications. The simple geometry of the test specimen, a cylindrical bar, makes it ideal for evaluating new materials where only limited quantities of the ma…
Unusual Michael reaction of acyclic 1,3-dicarbonyl compounds with nitre-olefins. A novel pyrrole synthesis
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…
Influence of Temperature on Corrosion Product Film Formation on CuNi10Fe in the Low Temperature Range: I. Corrosion rate as a function of temperature in well aerated sea water
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…
Partial Discharge Testing under Direct Voltage Conditions
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…
Corrosion Characteristics of High Purity Iron
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…
Origin of the coloration of yellow fluorites: The O3− center structure and dynamical aspects
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, Ba2V24+(O2|Si4O12), a new mineral from the Mogurazawa mine, Gumma Prefecture, Japan.
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…
The physics and display applications of liquid crystals
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…
Grain Boundary Sliding with and without Matrix Slip Deformation in Cadmium Bicrystals
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…
Embrittlement of zircaloy-4 due to oxidation in environment of stagnant steam.
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 influence of homeotropic and planar boundary conditions on the field induced cholesteric-nematic transition
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.
Effect of a Magnetic Field on the Rate of Diffusion-Controlled Corrosion of Metals
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.
Studies on the constituents of asclepiadaceae plants. LI. Oxidation at the 18-methyl group of C/D-cis-pregnane type steroids and 13C-nuclear magnetic resonance spectra of 18-oxygenated pregnanes and related compounds.
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…
Spherical agglomeration of aminophylline crystals during reaction in liquid by the spherical crystallization technique.
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…
Optical determination of viscoelastic properties of nematic OHMBBA
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…
THERMAL STRESSES IN A NONHOMOGENEOUS THICK PLATE UNDER STEADY DISTRIBUTION OF TEMPERATURE
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…