Materials Literature
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Brillouin shifts and the line widths in NH 4 HSO 4 which concern the longitudinal phonons propagating along the a * , b and c directions were measured in the temperature range -115∼30°C. The Brillouin shift caused by the pure longitudinal acoustic phonons propagating along the b axis shows an abrupt decrease and the l…
A series of coloured compounds of general formula CsPb1–xSnxX3(X3= Br3 or Br2Cl) has been prepared. X-Ray and Mössbauer data show that the compounds have highly symmetrical tin–lead environments. Their electronic resistivity and optical-reflectance spectra are interpretable in terms of the partial filling of electroni…
An investigation of hydrogen diffusion in a martensitic Type 403 stainless steel subjected to heat treatment was carried out in an attempt to establish the effect of heat treated microstructure on diffusivity and solubility of hydrogen. The diffusivity and solubility vary with the microstructure and the diffusion coef…
The salt Na2[Ru(NO)(NO2)4(OH)] reacts with barbituric acid in water to give Na[Ru(H2va)3](H2va–= bidentate violurate), and with 1,3-dimethylbarbituric acid to give Na[Ru(dmva)3](dmva–= bidentate 1,3-dimethylviolurate). The complexes react with Na[NO2] in acidic aqueous solutions to afford a series of novel diamagnetic…
Ultraviolet photoemission spectroscopy (UPS) has been used to study the valence-band electronic structure of $2H\ensuremath{-}\mathrm{M}\mathrm{o}{\mathrm{S}}_{2}$. The samples were cleaved or heated in ultrahigh vacuum of \ensuremath{\sim} 1 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}10}$ Torr to achieve…
ポリスチレンの熱分解反応を流通系充てん層反応器で実施するとともに,生成物の同定を行なった。熱処理試料(280℃/hr)と原試料の熱分析では,低温度領域と高温度領域の二段階反応が存在し,熱劣化の影響は低温度領域の活性化エネルギーに顕著に示された。原試料54.7kcal/mol,熱処理試料30.2kca1/molが得られた。処理温度2500C,1時間以下では原試料とかわらない。同定した成分は20種類,そのなかの主要なものは,α-メチルナフタレン,ビフェニル,1,2-ジフェニルプロバン,1,2-ジフェニルー1-プロペン,1,3-ジフェニルー1-プロペンである。不揮発成分は500℃ではワヅクス,350。Cでは二量体相当留分のグリース状であ…
Abstract The desupersaturation of nickel ammonium sulphate aqueous solutions, during the precipitation of the hydrated salt, has been followed by refractive index measurements. The addition of seed crystals has a considerable effect on the desupersaturation process: the induction and latent periods and the crystal siz…
L'analyse, aux petits angles de diffusion, des spectres de pertes d'énergie d'électrons rapides traversant des films de carbone amorphe de 40 Å d'épaisseur nous a permis de mettre en évidence l'existence de deux plasmons de surface (ħωs1 ≃ 5,25 eV et ħωs2 ≃ 19,75 eV), dont la dispersion diffère nettement de celle qui…
Aluminum in soil saturation extracts and exchangeable Al determined by N KCl extraction were studied using a large number of Ultisol and Alfisol samples from West Africa. The concentration of soil solution Al ranged from 0.05 to 4.5 ppm. Solution Al content was generally higher in the surface horizon (Ap and A1) than…
A number of β-diketonates of cerium(III), [NEt4][CeIIIL4], and cerium(IV), [CeIVL4], have been prepared and their spectra have been recorded in the visible and u.v. regions. The spectra of the cerium(III) complexes show a group of two or three bands of moderate intensity at frequencies just below those of the strong i…
Abstract The kinetics of precipitation of barium chromate from well‐stirred aqueous solutions of initial solute concentrations C 0 = 0.0001 to 0.0010 M (supersaturations 8 to 80) was studied at 25 °C by conductivity measurements and chemical analysis. Nucleation occurred during induction periods and regular crystal gr…
Fifty percent of human uterine collagen has been solubilized by limited pepsin digestion. Carboxymethyl cellulose-, Bio-gel A-5m-chromatography and amino acid analysis revealed that the solubilized collagen consists of 20% Type III and 80% Type I collagen. Reduction and alkylation reactions indicated that the alpha1(I…
The magnetic structure of NiWO 4 has been determined from neutron-diffraction measurements on single-crystal specimens. It is a collinear anti-ferromagnet in which the nickel ions have moments of 2.25 ± 0.04 μ B at 19.4 ± 2.6° to the c axis in obtuse β . The form factor of the Ni ++ ions follows closely the free-ion f…
The crystal structures of Cs2Na[Fe(CN)6](I) and Cs2K[Fe(CN)6](II) have been elucidated by single-crystal X-ray analysis and compared with that of Cs2Li[Fe(CN)6]. Crystals of both are monoclinic, space group P21/n, with Z= 2 in unit cells of dimensions: (I), a= 10.870(1), b= 7.709(1), c= 7.573(1)Å, β= 89.994(6)°: (II),…
Peaks observed in the temperature dependence of the dielectric constant of SrTiO3 glass ceramics do not appear in the dc polarization. A remanent polarization is observed between 4 and 77 K. The dielectric properties at low temperature are attributed to the relaxation of permanent dipoles to an electret state rather t…
The temperature dependence of internal friction was measured from 100 to 350 K at a frequency of about 700 Hz for hydrogen-charged 310S, 316 and 304 stainless steels. A characteristic relaxation peak due to dissolved hydrogen was found at about 280 K, on which there is little information in the literature. The charact…
The physical and functional properties of the mRNA population from developing embryos of the brine shrimp Artemia salina were characterized. About 20% of the total poly(A)-rich mRNA in these embryos appears to be specifically associated with the membrane fraction throughout early development, and physically differs ma…
Local field effects are calculated in the R.P.A. approximation from two extreme points of view. The first consists of an analytical inversion of the dielectric matrix in reciprocal space. If confirms the results of recent numerical calculations, that local field effects tend to reduce the dielectric constant. The seco…
The critical potential of hydrogen absorption and the hydrogen absorption rate into titanium under catholic polarization have been measured in artificial sea water with flow velocity of 2.0m/sec and then the effect of flow velocity, dispersed sand, dissolved zinc ion and dissolved chlorine or oxygen gas on the hydroge…
Streaming due to thermal surface tension gradients — the so-called Marangoni effect in isotropic fluids - has been observed in thin droplets of nematic liquid crystals deposited on a glass substrate. The coupling between the molecular orientation and the hydrodynamic flow induces distortions in the molecular alignment…