Materials Literature
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Transient photoconductivity has been used to measure the electron drift mobility in the ${c}^{\ensuremath{'}}$ direction of single-crystal naphtalene from 54 to 324 K. Below 100 K the mobility rises exponentially with decreasing temperature, an effect which we attribute to the onset of band-type motion limited by opti…
Using a self-consistent pseudopotential approach, band structures and charge densities have been calculated for trigonal Se and Te at hydrostatic pressures just below the transition to the metallic phase. The results are compared to zero pressure calculations and experimental data. Very good agreement between experime…
The Kirkwood theory of solutions of spherical ions is applied to aqueous solutions of macroions plus counter ions and to macroions in strong salt solutions. It is shown that the theory exhibits a mean field phase transition which is interpreted as a transition to the crystalline phase. The theory provides a qualitativ…
The specific heat Cpx has been measured for the binary system triethylamine–water as a function of temperature near the critical solution temperature at the critical concentration. Simple power law fits of the data resulted in rather large values (around 0.25) for the critical exponent α. For a fixed value of α equal…
The diffusion of $^{95}\mathrm{Nb}$ in niobium has been measured between 1353 and 2693 K. The data showed nonlinear Arrhenius behavior and fit the expression $D=[8\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}\mathrm{exp}(\ensuremath{-}3.62 \mathrm{eV}/\mathrm{kT})+3.7\mathrm{exp}(\ensuremath{-}4.54 \mathrm{…
In an array of one-dimensional conductors, fluctuations in the phase of the charge-density wave lead to changes in the electron density which are coupled by long-range Coulomb interactions. The Coulomb effect has a profound influence on the dynamics of the charge-density wave as observed by inelastic-neutron scatterin…
The electronic properties of the regular graphite lattice are investigated within self-consistent LCAO (linear combination of atomic orbitals) scheme based as a modified extended-H\"uckel approximation. The band structure and interband transition energies agree favorably with previous first-principles calculations. Go…
Estimates show that both the on-site and the near-neighbor electrostatic interactions in tetracyanoquinodimethane chains may be much greater than the bandwidth. A method of determining the exact ground state when the interactions are dominant is described; the electrons are found to have a periodic arrangement which m…
We study the effect of impurities on the dynamics of charge-density waves. At low temperature it is a good approximation to restrict our attention to phase fluctuation only. The competition between the random impurity potential and the elastic energy for phase fluctuations leads us naturally to consider two limiting c…
A new atomic number correction is proposed for quantitative electron-probe microanalysis. Analytical expressions for the stopping power S and back-scatter R factors are derived which take into account atomic number of the target, incident electron energy and overvoltage; the latter expression is established using Mont…
Abstract Mg-Al alloys decompose on ageing via a cellular reaction that produces large cells ( ca. 5-50 μm in diameter) consisting of alternating fine lamellae of Mg-Al solid solution and Mg17 Al12 intermetallic compound. This paper reports direct, high resolution microanalysis of individual points in cells formed by a…
An electron beam passing through a deflecting field is, in general, subject to aberrations such as distortion, astigmatism and coma in accordance with the deflecting angle. Accordingly, aberration defects of deflected beam are most serious limiting factor in performance of high resolution scanning electron microscopes…
日本短角種では,寒冷な山岳地帯において生産,育成された肥育素牛は,温暖な平地に移動して肥育することにより,寒冷な平地における肥育の場合に比べて肥育効率が脂肪交雑の増大という質的な面で向上することを既に報告した1).本調査では,寒冷地において実用化されている保温および換気に留意された無窓牛舎内における肥育効率について明らかにするために,日本短角種および黒毛和種を対象として,それらの血清中のグルコース,中性脂肪,遊離脂酸,燐脂質,総コレステロールなどの濃度を測定し,その結果を前記の調査成績と比較し,脂質代謝の面から検討した.日本短角種において,無窓牛舎内に肥育されている群は,寒冷平地肥育の群とは著しくその成績を異にし,温暖な平地に移動…
It has been shown by several investigations1,2 that AgNa(NO2)2, is a ferroelectric crystal which undergoes a phase transition of the first order, close to a second order one, at about 38°C. The transition may be assumed to be of the order-disorder type with the NO-2-groups forming the permanent electrical dipoles. The…
Measurements of thermal expansion, Young’s modulus, magnetic susceptibility and electrical resistivity at −150∼500°C, and hardness and density at room temperature have been made for annealed Mn–Pt alloys. It has been found that Mn-10.05∼40.21% Pt alloys cooled slowly after heating at 1100°C for 4 h have distinct anoma…
Alloy is a term commonly associated with metals and implies a composite which may be sinqle phase (solid solution) or heterophase. Whichever the case, metallic alloys generally exist because they exhi
Efforts directed towards perfecting the contemporary electron-microscopic devices require improvements in quality of focusing elements, creation of high-parameter lenses, together with tendency to greater simplicity in design. One of possible solutions of this problem is the employment of electrostatic crossed lenses…
This paper deals with the growth, conductivity, dielectric properties and visible absorption of Nb doped barium titanate single crystals grown from a KF flux. A chemical analysis was performed which exhibits the different kinds of compensation mechanisms. The transition temperature and the spontaneous polarization are…
薄片状や繊維状以外の結晶粉末で,通常の試料支持法では選択配向を起こしやすく,これにより回折線強度の再現性が悪くなる試料として,斜方晶系酸化鉛(II)を用い,数mg以下の場合でも可能な無配向測定試料の作製法を研究した.まず,粉末試料の分散ふりかけ装置を試作した.次いで,無反射試料板にはった粘着テープにガラスやイオン交換樹脂の微粒を一層だけ付着させたものや,アルミニウム製試料ホルダーにはった薄い布に粘着剤を付けたもの,その他の上に,この分散装置を用いて試料をふりかけ付着させ,回折線強度を測定した.その結果,粘着テープに(100～150)メッシュのガラス粒を付着させたものやストッキング用ナイロン製布を用いて,ほぼ無配向で回折線相対強度の…
1. Introduction. The Cambridge University 600 kV high resolution electron microscope has been developed as a joint programme between the Department of Engineering and the Department of Physics. The shorter electron wavelength at 600 kV when compared to 100 kV gives a potential improvement in resolution that can only b…