Showing papers by "Tohoku University published in 1972"
TL;DR: In this article, Tanno has classified connected almost contact Riemannian manifolds whose automorphism groups have themaximum dimension into three classes: (1) homogeneous normal contact manifolds with constant 0-holomorphic sec-tional curvature if the sectional curvature for 2-planes which contain
Abstract: Recently S. Tanno has classified connected almostcontact Riemannian manifolds whose automorphism groups have themaximum dimension [9]. In his classification table the almost contactRiemannian manifolds are divided into three classes: (1) homogeneousnormal contact Riemannian manifolds with constant 0-holomorphic sec-tional curvature if the sectional curvature for 2-planes which contain
614 citations
TL;DR: A combination of the three-second power law, presented in part I for wind waves of simple spectrum, and the similarity of the spectral form of wind waves, leads to a new concept on the energy spectrum of wind wave as mentioned in this paper.
Abstract: A combination of the three-second power law, presented in part I for wind waves of simple spectrum, and the similarity of the spectral form of wind waves, leads to a new concept on the energy spectrum of wind waves. It is well substantiated by data from a wind-wave tunnel experiment.
308 citations
TL;DR: In this paper, a neutron diffraction study was carried out on SrFeO 3, and the results indicated that the magnetic structure is a helical one with the helicoid vector k ; k // and | k |=0.112 a *.
Abstract: A neutron diffraction study was carried out on SrFeO 3 . The results indicate that the magnetic structure is a helical one with the helicoid vector k ; k // and | k |=0.112 a * . The Fe 4+ magnetic moment is 2.7±0.4 µ B at liquid nitrogen temperature.
234 citations
TL;DR: The time-dependent mechanical properties of amorphous Pd-20 at.% Si, i.e., fracture-strain rate effect, load relaxation, creep and elastic after effect characteristics, were determined as a function of both stress and temperature as discussed by the authors.
163 citations
TL;DR: In this article, the catalytic activities of transition-metal catalysts in methane formation from carbons were investigated at temperatures up to 1050 °C under atmospheric pressure of hydrogen, and it was shown that methane was produced in several stages and the temperature of maximal rate varied from one metal catalyst to another.
153 citations
TL;DR: In this paper, a theory of cooperative Jahn-Teller effect was developed for the purpose of discussing the spontaneous crystal distortions in mixed chromites, where the self-energy of each ion having a degenerate orbital level was separated from those energies which contribute to the cooperative phenomenon.
Abstract: A theory of the cooperative Jahn-Teller effect is developed for the purpose of discussing the spontaneous crystal distortions in mixed chromites, Cu 1- x Ni x Cr 2 O 4 and Fe 1- x Ni x Cr 2 O 4 The static Jahn-Teller effect only is taken into account The theory separates the self-energy of each ion having a degenerate orbital level from those energies which contribute to the cooperative phenomenon; the former energy represents the effect of a local distortion which persists in the cubic phase The theory also distinguishes between the contributions of the Jahn-Teller coupling with the bulk strains and with relative displacements of ions The theory explains successfully various features of the phase diagrams of the mixed chromites such as the concentration dependences of the transition temperatures and the magnitudes of the distortions, the appearance of an orthorhombic phase, etc The temperature dependence of elastic moduli is also discussed to point out that it will yield additional informations, pa
124 citations
01 Sep 1972
TL;DR: In this paper, the first experimental demonstration of the generation of a radially polarized optical beam mode by laser oscillation was reported, where a new type of discharge tube having the optical windows perpendicular to the optic axis was used, and a newly designed conical mode selector was inserted in the optical resonator.
Abstract: The first experimental demonstration of the generation of a radially polarized optical beam mode by laser oscillation is reported. In the experiment, a new type of discharge tube having the optical windows perpendicular to the optic axis is used, and a newly designed conical mode selector is inserted in the optical resonator.
122 citations
TL;DR: In this paper, the effect of an increase of particles in the atmosphere on the global albedo and accordingly on the thermal regime of the earth is studied by solving the equation of radiative transfer in model turbid atmospheres.
Abstract: The effect of an increase of particles in the atmosphere on the global albedo and accordingly on the thermal regime of the earth is studied by solving the equation of radiative transfer in model turbid atmospheres. Realistic model atmospheres with respect to size and vertical distributions of aerosol as well as reflectivity of the earth surface are assumed, and reflectivity at the top of the atmosphere, transniissivity at the earth surface, and absorptivity of turbid atmospheres are calculated as a function of atmospheric turbidity and the complex refractive index of the aerosol. It is shown that the thermal effect of increasing atmospheric turbidity is greatly affected by the imaginary part of the refractive index. Thus, if it takes a small value as is believed so at present, the earth-atmosphere system cools ofF with increase of turbidity, while if its value is large (ni0.05, ni being the imaginary part of the complex refractive index), heating of the earth- atmosphere system is expected due to...
111 citations
TL;DR: SrCoO 2.5 with brownmillerite (4CaO·Fe 2 O 3 ·Al 2O 3 ) type structure is an antiferromagnet with the Neel temperature of 570 K.
Abstract: SrCoO 2.5 with brownmillerite (4CaO·Fe 2 O 3 ·Al 2 O 3 ) type structure is an antiferromagnet with the Neel temperature of 570 K. The magnetic structure as determined from a neutron diffraction study is of G-type and the Co 3+ magnetic moment is 3.3±0.5µ B at liquid nitrogen temperature.
111 citations
TL;DR: In this article, the formation of F, H and α centers and self trapped excitons was investigated in KBr crystals by the irradiation of the pulsed electron beam from a Linac (30MeV, 0.8A, 20ns) and a Febetron 706 (0.6MeV, 7000A, 3ns).
Abstract: Transient formation of F, H and α centers and self trapped excitons has been investigated in KBr crystals by the irradiation of the pulsed electron beam from a Linac (30MeV, 0.8A, 20ns) and a Febetron 706 (0.6MeV, 7000A, 3ns). The α center concentration is at most 1/25 of the F center. The F and H center pair is concluded to be the primary product. The fast growth times of F and H centers, which are shorter than 3ns, suggest that the lowest. triplet and singlet states of the trapped exciton do not have any direct participation in the F center formation.
108 citations
TL;DR: Samples of the system SrCo 1- x Fe x O 3- y (0≤ x ≤ 1, 0≤ y ≤ 0.5) have been prepared under varying oxygen pressure and temperature and their crystal-lographic and magnetic properties have been studied.
Abstract: Samples of the system SrCo 1- x Fe x O 3- y (0≤ x ≤1, 0≤ y ≤0.5) have been prepared under varying oxygen pressure and temperature and their crystal-lographic and magnetic properties have been studied. SrCoO 2.5 with brown-millerite type structure (high temperature phase) is an antiferromagnet with the Neel temperature of 570 K and the Co 3+ -O 2- -Co 3+ superexchange interaction is strongly antiferromagnetic. SrCoO 3 and SrCo 1- x Fe x O 3 ( x <0.9) with the cubic perovskite structure (high temperature phase) are ferromagnetic with the Curie temperature at about 200 K and the magnetization decreases rapidly with increasing x near SrFeO 3 whose magnetic structure is helical.
TL;DR: In this paper, the resonance Raman effect of the I − 1 3 ion was observed by the use of an ultraviolet nitrogen pulsed laser, and it was found that the totally symmetric stretching vibration of 112 cm −1 undergoes selective enhancement and the overtones up to the seventh order of this vibration could be observed.
TL;DR: In this article, the effects of the density dependence of the ion-ion interaction are found quite important for the pressure in alkali metals, such as Zn, Al and Pb.
Abstract: Pressure and compressibility of simple metals such as alkali metals, Zn, Al and Pb are calculated in the liquid state near the triple point, using the pseudopotential formalism for electron-ion interaction. Effective ion-ion interaction is defined naturally by calculating the total energy of metals to the second order of the electron-ion pseudopotential and its contributions to pressure and bulk modulus are calculated separately by the use of the so-called pressure equation of state modified properly to include the effects of the density-dependence (due to the electronic screening effect) of the effective ion-ion potential. It is found that these contributions are much larger (of more repulsive nature) than those estimated by using the Percus-Yevick solution for the hard-sphere model. The effects of the density dependence of the ion-ion interaction are found quite important for the pressure in alkali metals. Comparison of the calculated values of compressibility with experiments is made and the agreement ...
TL;DR: The Co 59 nuclear magnetic resonance in a bulk specimen of hexagonal cobalt has been observed as a function of temperature from 4.2 K to 730 K in this article.
Abstract: The Co 59 nuclear magnetic resonance in a bulk specimen of hexagonal cobalt has been observed as a function of temperature from 4.2 K to 730 K. The hyperfine fields at nuclei at the edge and center of the domain wall are determined to be 217.7 and 225.7 kOe at 4.2 K, respectively. The difference between the two hyperfine fields, 8.0±0.1 kOe, comes mainly from the anisotropy in the orbital field and partly from that in the dipolar field. The value of e 2 q Q h -1 is 2.90±0.07 MHz at 4.2 K. The asymmetry in the charge distribution deduced from the electric field gradient q is very small. The isotropic hyperfine field is 223.0 kOe at 4.2 K and is larger by 8 kOe in its absolute value than that in cubic cobalt.
01 May 1972
TL;DR: In this article, the authors reviewed the recent progress of the laser radar method, providing single-ended and range-resolved means for remote detection and analysis of various molecular species in the polluted as well as ordinary atmosphere, based on the existence of their Raman backscattering.
Abstract: This paper reviews the recent progress of the laser radar method, providing single-ended and range-resolved means for remote detection and analysis of various molecular species in the polluted as well as ordinary atmosphere, based on the existence of their Raman backscattering; simply called the laser-Raman radar method A brief description is given of the operational principle including the basic concept and fundamental characteristics of this scheme, along with critical discussions of their advantages The differential backscattering cross section and the spectral distribution of Raman scattering of molecular species present in the atmosphere are discussed and summarized from the practical view-point for providing molecular density evaluation and interference-free detection After presenting experimental approaches of the laser-Raman scheme to show the feasibility of in-field monitoring and analysis of chemical species in various air conditions, the estimation of molecular concentrations is performed from observed Raman spectra Analytical discussions on the minimum detectable concentration and the range detectivity are also presented to indicate the present capability and limitation of this laser-Raman technique The potentiality for further progress in resonance Raman scattering for range-resolved measurement of dispersed pollutants in ambient air is pointed out
TL;DR: In this article, it has been shown that the ratio (K2/K1) of the position of the first peak to that of the second peak in the structure factor is a very useful parameter to represent the structure of liquid metals.
Abstract: X-ray diffraction patterns have been obtained from liquid metals (Al, Ga, In, Tl, Pb, Sn, Bi) near the melting point. After calculating the structure factor (Fourier analysis), the atomic radial distribution function was evaluated from which interatomic distance and coordination number were obtained. It has been shown that the ratio (K2/K1) of the position of the first peak (K1) to that of the second peak (K2) in the structure factor is a very useful parameter to represent the structure of liquid metals.
Rontgenbeugungsbilder von flussigen Metallen (Al, Ga, In, Tl, Pb, Sn, Bi) wurden in der Nahe des Schmelzpunktes beobachtet. Durch eine schon mehrfach dargestellte Methode (Fourier-Analyse) wurde der Strukturfaktor in eine radiale Atomverteilungsfunktion transformiert, aus der sich der mittlere Abstand nachster Atome und die Koordinationszahl ergeben. Es wurde gezeigt, das das Verhaltnis (K2/K1) der Lage des ersten Maximums (K1) zu der des zweiten Maximums (K2) im Strukturfaktor ein nutzlicher Parameter zur Beschreibung der Struktur von flussigen Metallen ist.
TL;DR: The results indicate that active transport of sugar markedly alters the potential profile across the proximal tubule of newt kidney, and that the primary event induced by sugar transport may be the depolarization of the luminal membrane.
TL;DR: In this paper, a number of azulene derivatives were determined in cyclohexane at room temperature and it was found that the yield decreases with the decrease of the energy gap between the first and the second excited states and that the rate constant of radiationless transition increases exponentially with decreasing ΔE.
TL;DR: It was assumed that hemin controls the level of ALA synthetase in liver mitochondria firstly by suppressing the initiation of induction of AlA Synthetase and secondly by inhibiting the conversion of the “soluble form” ofALA synthenase into the ”mitochondrial” ALA syntheticase.
TL;DR: The responses of pituitary hormones to insulin-induced hypoglycemia, lysine-8-vasopressin infusion and arginine infusion were examined in patients with Cushing's syndrome and plasma ACTH was not detectable at any time during all of the studies.
Abstract: The responses of pituitary hormones to insulin-induced hypoglycemia, lysine-8-vasopressin infusion and arginine infusion were examined in patients with Cushing's syndrome. In patients with adrenal hyperplasia, basal levels of plasma ACTH were slightly elevated and responses were preserved to both insulin-induced hypoglycemia and lysine-8-vasopressin infusion, though the magnitude of response was variable. All of the patients had an increase of plasma 11-hydroxycorticosteroids following lysine-8-vasopressin. After insulin-induced hypoglycemia, 11-hydroxycorticosteroids increased in only half of the patients. In patients with adrenal adenomas, plasma 11-hydroxycorticosteroid concentrations did not increase after insulin-induced hypoglycemia but there was a rise observed after lysine-8-vasopressin infusion. However, in patients with adrenal adenomas plasma ACTH was not detectable at any time during all of the studies. There was usually no increase of plasma GH concentration in response to any of the stimuli....
TL;DR: Protoplasts isolated enzymatically from carrot root tissues developed into cell clusters in a liquid medium containing coconut milk and naphthaleneacetic acid (NAA) or 2,4-dichlorophenoxyacetic Acid (2,4,D) and differentiated into embryoids on an agar medium containing Coconut milk or kinetin.
Abstract: Protoplasts isolated enzymatically from carrot root tissues developed into cell clusters in a liquid medium containing coconut milk and naphthaleneacetic acid (NAA) or 2,4-dichlorophenoxyacetic acid (2,4-D). Cells of the resulting calluses differentiated into embryoids on an agar medium containing coconut milk or kinetin.
TL;DR: In this paper, the authors measured the reflectivity spectra of single crystals from 2.0 to 6.6 eV through the whole range of mole fraction $x$ at room temperature.
Abstract: Reflectivity spectra of $\mathrm{Zn}{\mathrm{Se}}_{x}{\mathrm{Te}}_{1\ensuremath{-}x}$ single crystals were measured from 2.0 to 6.6 eV through the whole range of mole fraction $x$ at room temperature. The variation of the band gaps such as the ${E}_{0}$, ${e}_{1}$, ${E}_{1}$, and ${E}_{2}$ with $x$ is reported. The ${E}_{0}$, ${e}_{1}$, and ${E}_{1}$ gaps exhibit spin-orbit splitting. The lowest gap ${E}_{0}$ shows a minimum in energy at $x=0.33$. The minimum value is 2.13 eV.
TL;DR: Host dependency of the antiviral effect of chloroquine on Newcastle disease and Sendai viruses was shown using HeLa S 3 cells and primary chick embryo fibroblast cells and no evidence for inhibition of the virus uncoating process by the drug was obtained.
Abstract: The effect of chloroquine diphosphate on the growth of polio type 1, influenza, Newcastle disease, Sendai, vesicular stomatitis and vaccinia viruses was studied Host dependency of the antiviral effect of chloroquine on Newcastle disease and Sendai viruses was shown using HeLa S 3 cells and primary chick embryo fibroblast cells The antiviral effect of chloroquine was extensively studied in chick embryo cells infected with vesicular stomatitis virus Chloroquine at a concentration of 125 μg per ml markedly reduced the virus yield The drug did not affect the adsorption of vesicular stomatitis virus to chick embryo cells No evidence for inhibition of the virus uncoating process by the drug was obtained in our present system The addition of chloroquine at various times after the latent period induced immediate inhibition of the synthesis of progeny virus Chloroquine inhibited selectively the synthesis of viral RNA without affecting that of cellular RNA or the synthesis of viral antigens
TL;DR: Erabutoxin c, a minor neurotoxic component of the venom of a sea snake Laticauda semifasciata, was isolated in pure form by repeated column chromatography on CM-cellulose columns and concluded that it was [51-asparagine]-erabut toxin b.
Abstract: Erabutoxin c, a minor neurotoxic component of the venom of a sea snake Laticauda semifasciata, was isolated in pure form by repeated column chromatography on CM-cellulose columns. The toxin was crystallizable and monodisperse in rechromatography, disc electrophoresis and isoelectric focusing (isoelectric point, pH9.23–9.25). The molecular weight of the toxin, as estimated by gel filtration, was 7000. The toxin showed the same lethal activity to mice (0.13μg/g body wt., intramuscular injection) and the same effect on isolated frog muscle as erabutoxins a and b, the main toxic components of the venom. The toxin inhibited the acetylcholine contracture but not the potassium chloride contracture of muscle. Erabutoxin c consisted of 62 amino acid residues, containing one fewer lysine and one more histidine than erabutoxin a and one fewer lysine and one more aspartic acid (or asparagine) than erabutoxin b. Erabutoxin c was reduced, S-carboxymethylated and hydrolysed with trypsin. The only fragment different from the corresponding fragments from erabutoxin b was hydrolysed further with pepsin. One of the peptic fragments, which was assumed to have the aspartic acid (or asparagine) residue in question at the C-terminal end, was treated with carboxypeptidase A. The C-terminal residue was found to be an asparagine. It was therefore concluded that erabutoxin c was [51-asparagine]-erabutoxin b.
TL;DR: In this paper, an extended perturbation theory of IV and III-V covalent semiconductors based on a model pseudopotential method is presented, in addition to the usual second order perturbations, higher order terms with respect to pseudo-potential corresponding to the bonding effect are taken into account under the so-called isotropic energy gap model.
Abstract: An extended perturbation theory of IV and III-V covalent semiconductors based on a model pseudopotential method is presented. In the theory, in addition to the usual second order perturbation, higher order terms with respect to pseudopotential corresponding to the covalent bonding effect are taken into account under the so-called isotropic energy gap model. The theory is applied to calculation of cohesive energies and compressibilities of these crystals. A good agreement between the theory and experiment is obtained.
TL;DR: In this paper, features of the phase equilibria of hydrogen-light hydrocarbon mixtures were discussed, and the Benedict-Webb-Rubin equation was successfully applied to predict the vapor-liquid equilibrium of the present systems above the normal boiling point.
Abstract: The vapor-liquid equilibrium relations of the hydrogen-methane, the hydrogen-ethylene, The hydrogen-ethane, the hydrogen-methane-ethylene and the hydrogen-ethylene-ethane systems were determined by a static method at several temperatures from -25°C to -170°C and at pressures up to 100 atm. From the data obtained, features of the phase equilibria of hydrogen-light hydrocarbon mixtures are discussed. The Benedict-Webb-Rubin equation was successfully applied to predict the vapor-liquid equilibria of the present systems above the normal boiling point of the heaviest hydrocarbon.
TL;DR: It is shown that a variation in infectivity for L cells and in the hemolytic activity of L Sendai is a type of host-controlled modification distinguishable from the density variation.
Abstract: Sendai virus grown in L cells (L Sendai) caused little hemolysis, whereas the one grown in fertile eggs (egg Sendai) induced distinct hemolysis. Enzymatic treatment with trypsin at low concentrations markedly enhanced the hemolytic activity of L Sendai but not that of egg Sendai. Both sonic treatment and freezing and thawing greatly enhanced the hemolytic activity of egg Sendai, but they gave little enhancing effect on that of L Sendai which could, however, be greatly increased by successive treatment with trypsin. Dose response and kinetic experiments on the trypsin effect have suggested that a similarity exists in the inhibitory mechanism of infectivity for L cells and hemolytic activity of L Sendai. Treatment of L cells with trypsin at later stages of infection released a highly hemolytic L Sendai from those cells. The present study, by reference to the density centrifugation studies in a previous report (4), has shown that a variation in infectivity for L cells and in the hemolytic activity of L Sendai is a type of host-controlled modification distinguishable from the density variation.
TL;DR: It was revealed that sulfate polysaccharide in the vegetal region moved toward the blastocoel in parallel with the shedding of the primary mesenchyme cells when the incorporation of sulfate into the acid mucopolysaccharides was inhibited by selenate, the primitive gut development was remarkably repressed.
Abstract: The occurrence of acid mucopolysaccharides in the early development of the sea urchin embryo was studied by histochemical stainings as well as by autoradiographic methods. By histochemical methods acid niucopolysacchdride was demonstrated at the vegetal region in the early stage of gastrulation as a globular structure. Experiments with 35S-labeled sulfate which was incorporated into acid mucopolysaccharides confirmed the result obtained by histochemical observation. It was revealed that sulfate polysaccharide in the vegetal region moved toward the blastocoel in parallel with the shedding of the primary mesenchyme cells. When the incorporation of sulfate into the acid mucopolysaccharides was inhibited by selenate, the primitive gut development was remarkably repressed. The substance seems to be indispensable for smooth cell movements essential for the gastrulation of sea urchin embryo.