Materials Literature
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Single crystals of $n$-${\mathrm{Bi}}_{2}$${\mathrm{Se}}_{3}$ were prepared with free-carrier concentration $N$ in the range $5\ifmmode\times\else\texttimes\fi{}{10}^{18}<N<2\ifmmode\times\else\texttimes\fi{}{10}^{20}$ ${\mathrm{cm}}^{\ensuremath{-}3}$. Results of the measurements of infrared reflectance, Seebec…
We show that a suitable electron paramagnetic resonance experiment can discriminate sufficiently against the predominantly harmonic fluctuations characterizing a system undergoing a displacive phase transition, that a cluster-induced order-disorder component of the local behavior is exposed. We find evidence that, at…
The dissolution of iron from carbon steel in aqueous H 2 S solutions has been studied as a function of time and temperature at 0.1 MPa H 2 S pressure using the rotating disc technique. The iron sulfide film formed on the disc surface has been identified by X-ray diffraction analysis. The solubility and dissolution rat…
The random-network model for amorphous alloys proposed by White has been developed for some Se-based amorphous semiconductors (Ge-Se, As-Se, and Se-As-Ge) annealed or irradiated with light. The model suggests that the photobleaching and the photodarkening in these systems may be due to change in the number of bonds. A…
The results of Raman scattering and infrared reflectivity studies of the mixed-valence ternary sulphide ${\mathrm{Sn}}^{\mathrm{II}}$${\mathrm{Sn}}^{\mathrm{IV}}$${\mathrm{S}}_{3}$ are presented. The infrared-active phonon frequencies and the dielectric constants for all the principal directions have been determined.…
The near-band-edge optical properties of a series of 15 crystals including the two binary compounds GaSe and GaTe have been investigated in great detail at 300, 77, and 1.6\ifmmode^\circ\else\textdegree\fi{}K. The absorption spectra at 77 and 1.6\ifmmode^\circ\else\textdegree\fi{} K show well-resolved excitonic struct…
Abstract The influence of shearing history on the viscoelastic properties of low‐density polyethylene (LDPE) is investigated. Swelling of extrudates from a melt indexer is measured for monitoring the variation in viscoelasticity. Continuous shearing of molten LDPE reduces the swelling ratio. The reduction is not due t…
Abstract A low molecular weight poly(ester urea), poly(L‐phenylalanine/ethylene glycol/1,6‐diisocyanatohexane), and a model diester diurea, dimethyldiphenylalaninehexamethylenediruea, were synthesized and found to be hydrolyzed by α‐chymotrypsin solutions at pH 7.8. After ten‐day exposure to 0.1 mg/ml enzyme solution…
Spectral, kinetic, and relative quantum intensity measurements are reported for a series of ${\mathrm{Y}}_{3}$${\mathrm{Al}}_{5}$${\mathrm{O}}_{12}$ (YAlG) crystals, both nominally undoped and activated by ${\mathrm{Ce}}^{3+}$ and ${\mathrm{Tb}}^{3+}$. The undoped crystal shows a complex emission band in the near uv w…
A new electromagnetic transducer configuration is described for generating horizontally polarized shear (SH) waves in ferromagnetic materials. The transducer consists of a meander coil and static bias magnetic field parallel to the coil elements. This configuration generates no ultrasonic waves in a nonmagnetic metal…
Single-crystal samples of $\ensuremath{\alpha}$-${\mathrm{Al}}_{2}$${\mathrm{O}}_{3}$ have been studied that were colored during growth. The samples initially contained a single absorption band at 6.1 eV with a half-width of 0.68 eV. The sample had to be heated to a over 1400\ifmmode^\circ\else\textdegree\fi{}C to rem…
Abstract The adsorption abilities of chitin and its congeners with two series of degrees of deacetylation prepared by two different deacetylation procedures were compared. Among the polysaccharides obtained by the heterogeneous method, those with higher amino group content had higher adsorption ability. Plots of colle…
Measurements are presented of the optical properties of the radical cation TT${\mathrm{F}}^{+}$ (tetrathiafulvalenium) in a variety of different conditions: as TT${\mathrm{F}}^{+}$ monomers in solution, as ${(\mathrm{T}\mathrm{T}{\mathrm{F}}^{+})}_{2}$ dimers in solution, in the monovalence (TTF)${\mathrm{Br}}_{1.0}$…
The fine structure in the angle-resolved secondary electron emission (SEE) spectra can be interpreted fully in terms of the electronic structure of the semi-infinite crystal. A large number of elements of structure can be related to the bulk band structure. In addition, extra features are unambiguously interpreted in…
Abstract The polymerization of 1‐vinylindole ( 1a ) induced by free radical and cationic initiators is studied and the structure of the resulting polymers is elucidated by 13 C NMR spectroscopy. Also 2‐methyl‐1‐vinylindole ( 1b ), 3‐methyl‐1‐vinylindole ( 1c ), and 2,3‐dimethyl‐1‐vinylindole ( 1d ) are polymerized in…
Abstract A method is presented for inverting the Fredholm integral equations of the first kind that arise in many experimental determinations of molecular weight distributions of high polymers. The well known problems of instability and nonuniqueness are minimized by constraining the distribution to be the smoothest n…
Ordered phases in Pd‐rich Pd‐Mn system were investigated by means of selected area electron diffraction and X‐ray powder diffraction methods. The stability range of the periodic one‐dimensional antiphase structure Pd3Mn on the equilibrium phase diagram and the composition and temperature dependence of antiphase domain…
FCC結晶粒よりなる多結晶板モデルを用いて,増分的結晶弾塑性有限要素法により,各種比例負荷下の応力-ひずみ曲線,等ひずみ曲線,後続降伏曲線,繰り返し負荷下のヒステリシスループの形成,идьюшннの遅れ現象,ひずみ経路急変直後の応力-ひずみ曲線の異常挙動(一時低下),およびメカニカルラチェット現象といった複雑多様な(巨視)塑性挙動をシミュレートし,本モデルの実際的意義を確認した.
石英ガラス, 5Na2O・95GeO2ガラス, Ca(PO3)2ガラス, ソーダ石灰ガラス及びパイレックスガラスの光弾性定数 (以下Bと略す) を測定した. 石英ガラスのBがソーダ石灰ガラスのBの1.33倍であることはWeyl説では説明できない. 石英ガラスでは主としてSiO44面体の6員環からなり, 環内には透き間がある. この構造への, 圧縮において共有する角頂の結合角が変化する変形によって透き間を埋める変形が起こり, これが8を正で大きくしているとして, Bへの寄与に対する新しい機構を提案した. GeO2, 5Na2O・95GeO2ガラスも同様である. ホウ酸塩ガラス, ホウケイ酸ガラスではtetraborate群及びdib…
The impulsive pressure pulses arising from copper wire explosions are measured using Hopkinson pressure bar technique under various charging voltages up to 63 kV, charging energies up to 2.6 kJ, natural frequencies of the discharge circuit from 10 kHz to 50 kHz and various wire dimensions, and impulses which are defin…