Materials Literature
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A new form of solid germanium, of greater density than ordinary cubic germanium, can be formed by compressing cubic germanium at pressures exceeding 120 kilobars and reducing the pressure back to that of the atmosphere. The crystal structure is tetragonal, with a equal to 5.93 angstroms and c, to 6.98; 12 atoms per un…
Hydroxylysine and hydroxyproline are absent in the calcified proteins of Mytilus. The organic matrices from the calcite layers have a consistently higher ratio of acidic to basic amino acids than the aragonitic shell units. The uncalcified shell units periostracum and outer ligament, have very few acidic residues, whi…
Abstract The main thermoluminescence glow curve, the a, B, y glow curve, of polyethylene irradiated by y-rays at 77 °K has been found to be greatly affected by molecular oxygen absorbed in the material before irradiation. The oxygen removes the B and y peaks almost entirely at low irradiation doses and adds another pe…
A mass spectrometer study was made to compare the transport characteristics of hydrogen and deuterium through hollow, thin walled cylinders of three types of fused quartz. The experiments in the temperature range (300°—1000°C) resulted in the following observations: (1) The permeability of hydrogen (and deuterium) in…
Electrical measurements have been made on CaB6, SrB6, BaB6, YB2, YB4, YB6, and YB12 for the purpose of testing models of the electronic structure of the boron atoms in the four boride types represented. The compounds CaB6, SrB6, and BaB6 were found to be semiconductors. The Hall coefficients of YB2, YB6, and YB12 were…
Abstract The theory of inelastic scattering is studied for the transmission of fast electrons through crystals when the fast electrons are described by Bloch waves so that Bragg reflexion is also considered. Solutions for the wave amplitudes are obtained for the case of small-angle inelastic scattering and it is shown…
The unusual temperature dependence of the elastic moduli and other physical properties of alpha uranium near 43\ifmmode^\circ\else\textdegree\fi{}K which have been previously reported are found to be correlated with changes in atomic position and with cell dimensions. The atom position parameter, $y$, decreases to a m…
The static magnetoelastic coupling in ferromagnetic or antiferromagnetic cubic crystals is analyzed in terms of a general formalism dictated by symmetry considerations. Besides the coupling of the spins to the external strains, resulting in external magnetostriction, the spins can also couple to internal strain modes.…
目的しわにおける繊維のレオロジカルな挙動と, 繊維間の相互作用について, 理論的な検討を加え, しわにおける両者の効果を実験的に分析し, さらに繊維の弾性測定方法のだ当性の検討を試みた.成果 (1) しわ角θ は純粋な繊維の弾性項θ1と繊維の相互作用の項θ2から構成され, θ ≒ θ1-θ2なる関係がなり立つ. (2) θ2は織物に適当なセット処理を施すか, 構成繊維の摩擦係数を低下させることによって, 減少する. (3) θ1は構成繊維の伸長緩和弾性実験における残留ひずみ率P.S.から求まるθe-180 (1-P.S./100) に対応している. (4) しわ付け時間によるしわ角の低下の速さ, および回復時間によるしわの回復速度…
Mitsumata trees may be cut down any day in autumn when they have shed their leaves. The bark of the trees which are cut down in autumn or March of the following year is called fuyu-kawa or the winter bark, while that of the trees are cut down since April is called haru-kawa, or the spring bark. According to tradition,…
Abstract Previous definitions of order (i.e., lateral order) in cellulose materials have been essentially in terms of the experimental method and order has been interpreted as the extent of hydrogen bonding. These definitions are inadequate. Order is defined herein as the difference in free energy of the element of po…
Because of high surface tensional force of molten copper, air atomized copper powders show spherical shape, and such powders have poor pressing properties, exhibiting low green strength.In the manufacture of porous bronze bearing, it is necessary to use copper powder of a substantially lower apparent density, with goo…
From the viewpoint of the surface renewal theory or the film penetration theory, mass transfer in a liquid film was considered.The theoretical equation (6) based on the surface renewal theory was derived by assuming that the surface age distribution should change with contact time and moreover that the liquid surface…
Specimens of the permanent magnet alloy “Vicalloy” composed of 2∼6% Cr, 6∼10% V, 52% Co and balance Fe were reduced to 93% by cold rolling and subsequent tempering at temperatures between 20° and 800°C. The measured magnetic properties were saturation induction, residual induction, coercive force and magnetic torque.…
MnAl alloy is most succesfully melted by high frequency induction furnace under argon atmosphere in alumina crucible. The alloy containing 68 to 70 wt% of Mn exhibits the highest saturation magnetization in this system. Ferromagnetic phase (π-phase) can be prepared by quenching and subsequent tempering. The adequate q…
Introduction. The first and second occurrences of kotoite, Mg3(B03)2, were reported by the first author from
3ZnO・Cr2O3およびZnO・2Fe2O3の触媒に活性減衰防止の目的で,活性炭,シリカゲル,ZnCl2等を添加して,酢酸ビニル合成反応を実験し,その効果を検討した。その結果,もっとも減衰防止に効果的な物質はZnClであることを知った。また3ZnO・Cr2O3とZnO・2Fe2O3触媒に対する担体の効果が活性炭とシリカゲルとで相反することは興味深いことである。これらの実験結果から結局80ZnO・160Fe2O3・32SiO2・11MnO2-5ZnCl2・V2O5の組成の触媒を得た。この触媒は温度250℃,アセチレンと酢酸とのモル比を1とし,SV=1700/hr,触媒量50mlの反応条件で,連続100時間にわたる長時間反応の後にお…
Proton magnetic resonance spectra of single crystals of two Tutton's salts, K2Zn(SO4)2·6H2O and K2Mg(SO4)2·6H2O, have been studied and the orientations of the water molecules in the structure have been determined. Using the heavy-atom structure of (NH4)2Mg(SO4)2·6H2O as determined by x-ray diffraction, a system of hyd…
One of the primary reasons for the failure of thermionic converters to attain their ultimate theoretical performance is electron transport effects occurring in the interelectrode spacing. Two major types of transport effects, electron scattering and electron space charge, are discussed and theoretical results compared…
Neutron diffraction study of the atomic and spin arrangement of the κ phase of ternary' alloys Cu 20 –Mn 30+ x –Al 50- x ( x =0 5 and 10) has beed performed. It is shown that, for alloys x ≠0, excess Mn atoms replace Al atoms at body center sites of CsCl type crystal lattice, and their spins couple antiparallel with t…