Showing papers by "Tohoku University published in 1968"

Anomalous Transport Phenomena in Eu-Chalcogenide Alloys

Abstract: Various anomalous optical, magnetic, and transport phenomena have been found in Eu-chalcogenide alloys. Anomalous optical properties are explained by the magnetic exciton in which a hole in the $4f$ conduction band and an electron (for optically active magnetic exciton) in the $5d$ conduction band make a bound state. Strong $d\ensuremath{-}f$ exchange interaction between the magnetic-exciton electron of $5d$ character and the $4f$ electrons in the surrounding ${\mathrm{Eu}}^{2+}$ ions is the origin of the anomaly. Anomalous magnetic properties in dilute ${\mathrm{R}}^{3+}$ alloys are explained by the properties of the giant spin molecule which comes from the strong $s\ensuremath{-}f$ exchange interaction between the impurity electron and the $4f$ electrons at the central ${R}^{3+}$ and the surrounding ${\mathrm{Eu}}^{2+}$. The anomalous transition from the hopping type to the metallic-impurity band conduction in dilute ${\mathrm{R}}^{3+}$ alloys is also explained by the temperature dependence of the activation energy due to the $s\ensuremath{-}f$ exchange interaction in the magnetic-impurity state.

Critical Fluctuation of the Order Parameter in a Superconductor. I

Abstract: The fluctuation of the order parameter in a superconductor in the temperature slightly above the transition temperature is studied in the framework of the current microscopic theory. It is convenient to divide the temperature region where the fluctuation of the order parameter becomes important into two regions; the classical and the' critical region. In the classical region the spatial correlation of the fluctuation is of the Ornstein-Zernike type, while in the critical region it depends on the relative distance like r-3/2. We show that the elec­ trical resistivity, the nuclear spin lattice relaxation time and the ultrasonic attenuation co­ efficient decrease like 1-ai1li- 1I2 and 1-a'i1li- 1I3 in the classical and in the critical region . respectively, where 1l= (TITe) -1 and a and a' are constants of the order (Telp.) 1/2 (lPo)-3/2 and (Tel p.) 1/3 (lpo) -1 respectively. Here p. is the chemical potential, l is the electronic mean free path and Po is the fermi momentum. It is also shown that the thermal conductivity has no singular term at the transition temperature.

Measurement of the Optical Constants of Yttrium Oxide

Abstract: By using a solar furnace, yttrium oxide crystals were grown by the fusion process. The crystals obtained were highly transparent in the spectral region from 0.25 to 9.6 µ. The refractive index in this region was measured by three different methods. The observed index values were well expressed by the dispersion formula. From the values of parameters in the formula, it was found that the center of the fundamental absorption and the lattice absorption were at about 0.139 and 22.9 µ, respectively. A brief discussion on the infrared and ultraviolet absorption edges is added.

Some clinopyroxenes from ultramafic inclusions in Dreiser Weiher, Eifel

Abstract: Eight clinopyroxenes from wehrlites and clinopyroxenites and three clinopyroxenes of crystal lapilli in tuff of Dreiser Weiher in Eifel, Germany, have been separated and chemically analysed. One hornblende and two phlogopites from a wehrlite and clinopyroxenites have also been analysed. The rocks enclosing these inclusions are alkali basalts of basanite composition. The analysed clinopyroxenes contain considerable amounts of Al2O3 (3.87–10.84 wt%). The calculated Tschermak's component ranges from 5.9 to 18.4 mol per cent. All of the analysed clinopyroxenes are clearly different from chromian diopsides in lherzolite inclusions in basaltic rocks in Dreiser Weiher and other localities; the former has higher contents of total FeO, CaO and TiO2 and lower contents of MgO and Cr2O3 than the latter. Two clinopyroxenes separated from apatite-bearing clinopyroxenites show high contents of Fe2O3 with about 2 per cent of Na2O, indicating the presence of considerable amounts of acmite component in addition to Tschermak's component. The relative proportions of Al in the tetrahedral site and that in the octahedral site in the analysed clinopyroxenes are clearly different from those of the common igneous clinopyroxenes and eclogites, and similar to those of the clinopyroxenes from other inclusions in basaltic rocks and granulites. It is suggested that all the analysed clinopyroxenes and their host inclusions have crystallized from alkali basalt magmas in relatively deep levels of the continental crust.

On the mechanism of drying of granular beds

Abstract: z = distance in the axial direction Greek Letters a/3 = ratio of the rate of lateral movement of fluid to the flow rate in the interior of the bed av = ratio of the rate of fluid displacement normal to the wall to the flow rate in the near-wall region ew = void fraction in the near-wall region $ = nondimensional radial distance = r/Rw y] nondimensional axial distance = z/Rw tC =ker/CpGoRw ft = viscosity of fluid [kg/m-h] v = kinematic viscosity of fluid [m2/h]

Mechanisms for the Anomalous Properties of Eu-Chalcogenides Alloys. I.

Abstract: Various anomalous magneto-optic and magnetic properties of Eu 1- x Gd x Se are explained on the magnetic exciton and the magnetic impurity state model. It is shown that the optically active magnetic exciton with the lowest energy is of the type of (5 d –5 d ), that is, 5 d character on the central Eu 3+ and also 5 d on the nearest neighbour Eu 2+ . The origin of the anomalous magneto-optic properties is attributed to the d – f exchange interaction on the nearest neighbour Eu 2+ ions. While, for the magnetic impurity state, (6 s –6 s ) type state has the lowest energy. At low temperature, a giant spin molecule ( S =46) composed of the spin of an impurity electron and the 4 f spin on the central Gd 3+ ion and the n.n.Eu 2+ ion is constructed through the s – f exchage interaction among them. However, this giant spin molecule disappears rather quickly as temperature increases exceeding J 1/κ , where J 1 is the s – f exchange constant at n.n. Eu 2+ and is estimated as 25κ. The anomalous magnetic properties of ...

Exciton Luminescence of CuCl, CuBr and CuI Single Crystals

Abstract: Emission, absorption and reflection spectra have been studied on single crystals of cuprous halides. Three types of emission are observed: 1) resonance emission due to the annihilation of the lowest energy intrinsic exciton, 2) narrow lines due to bound excitons at defects or impurities, 3)broad bands and overlapping equidistant narrow bands. In the excitation spectrum for the resonance emission a structure of equal spacing, which corresponds to the longitudinal optical (LO) phonon energy, is found in the exciton absorption band region at low temperatures below 40°K. The resonance emission bands in CuBr and emission lines belonging to the type 2) in CuI are accompanied by the LO phonon assisted satellite bands. The LO phonon energies are obtained as 210±12, 166±7 and 151±8 cm -1 in CuCI, CuBr and CuI crystals, respectively.

Dynamical interpretation of magnetic recording process

Abstract: The demagnetization effect in magnetic recording must be evaluated, not as static self-demagnetization, but as a dynamic demagnetizing field at an instant when the head field is applied to the medium. From this fact it becomes necessary to obtain a self-consistent magnetization distribution in the medium. A method of calculation and its results are described. The relation between the longitudinal and the vector magnetization is clarified. The experimental results of the recording demagnetization in sinusoidal recording and the pulse width and the peak shift in digital recording are interpreted as the new phenomena that is related to the dynamical behavior of the demagnetizing field in the recording process.

Obstruction of the inferior vena cava in the hepatic portion and the hepatic veins. Report of eight cases and review of the Japanese literature.

Abstract: From the First Department of Internal Medicine, Tohoku University School of Medicine, Sendai, Japan. In 1845 Budd’ reported three cases of obstruction of the hepatic veins. In 1899, after studying the results of three of his own cases and seven cases from literature, Chiari‘-’ emphasized that obstruction of the hepatic veins due to obstructive phlebitis should be classified as a distinct disease. Following the report of three cases by Yamagiwa3 in 1906, additional cases were studied and reported in Japan. By recent progress of venous catheterization techniques, the authors could diagnose clinically obstruction of the hepatic veins and/or the inferior vena cava in the hepatic portion in eight patients. In Japan, obstruction of the hepatic veins is frequently associated with obstruction of the inferior vena cava in the hepatic portion, peculiar features of which

Properties and Uses of Human–Mouse Hybrid Cell Lines

Abstract: Staged reduction of the chromosome complement of human–mouse hybrid cells has made possible the identification of the chromosome bearing the human gene for thymidine kinase. Effects of human chromosomes on the growth rate of hybrid cells are examined and the possibility of making further chromosomal assignments for human autosomal genes is discussed.

Isolation from a Salivary Gland of Granules Containing Renin and Kallikrein

Abstract: Granules of the submaxillary gland of the white mouse contain both kallikrein and renin. The granules were separated and concentrated in sequential centrifugation procedures. They were more stable at room temperature and in hypertonic sucrose solutions than in the cold or in isotonic solution. The amylase, acid phosphatase, renin, kallikrein, and benzoyl-L-arginine ethyl ester esterase contents of the granules were determined. Kallikrein and renin showed a similar distribution pattern after fractionation. Granular renin released the equivalent of 9.6 µg angiotensin II amide/mg enzyme protein/min from swine serum angiotensinogen. Granular kallikrein liberated from human kininogen the equivalent of 8.4 µg bradykinin/mg enzyme protein/min. Electron micrographs of the isolated granules showed various forms; some were spherical and symmetrical, and others were amorphous.

Vapor-liquid equilibria for binary and ternary systems containing carbon dioxide

Abstract: Vapor-liquid equilibria containing carbon dioxide: CO2-CO, CO2-Ar, CO2-CH4 and CO2-H2-CO were measured by static method at -50°C to 20°C and up to 200 atm. By using these data and the data available in literature, the extent of usefulness of the Benedict-Webb-Rubin equation (hereafter abbreviated as BWR equation) and the treatment of Leland et al. were studied. The BWR equation correctly predicted the vapor-liquid equilibria of inorganic mixtures except in the critical region, while the treatment of Leland et al. was insufficient.

Magnetic Structure of Ca2Fe2O5

Abstract: Magnetic measurements indicate that Ca 2 Fe 2 O 5 is an antiferromagnet, with weak parasitic ferromagnetism The lattice, with the space group Pcmn -D 2 h 16 , can be considered as an oxygen deficient perovskite The magnetic structure as determined from a neutron diffraction study is of G -type, and Fe 3+ spins are directed approximately along c -axis

Origin of some eclogite inclusions in kimberlite

Abstract: Of six eclogite inclusions in kimberlite of Roberts-Victor mine near Kimberley, South Africa, three are essentially bimineralic eclogites consisting of clinopyroxene and pyroperich garnet, and others contain phlogopite in addition to clinopyroxene and garnet. Clinopyroxenes are omphacites ranging in composition from a jadeite-poor variety (jadeite 9.9 mole 7) to a jadeite-rich variety (40.8%). Garnet ranges in composition from grossular 2.9 to 18.1 percent. Partition of Mg and Fe2+ between coexisting garnet and clinopyroxene in these eclogites is similar to those in the eclogites from other kimberlite pipes, but much difierent from those in eclogites from various metamorphic terrains, indicating that the physical conditions of their formation are different; eclogites in kimberlite were equilibrated in the upper mantle. Phlogopite in eclogites were probably formed within the upper mantle before the eruption of kimberlite. The compositions of the eclogites correspond to those of olivine basait or picrite basalt, although KrO content is considerably higher in two of them. As the Fe'z+/(Mgf Fe2+) ratio of the eclogite increases, AhOs of the eclogite increases, content oi jadeite in clinopyroxene and content of grossular in garnet increase. These reiations may be interpreted as due to the difierence in degree of partial melting of the mantle material (e.g., garnet peridotite) when the eclogite magmas were formedl magmas of lower degree of partial melting have higher Fe'z+/(Mg*Fe'+) ratio and higher jadeite and grossular components' whereas those of higher degree of partial melting approach the garnet peridotite in composition, having lower Fe'z+/(MgfFe'z+) ratio and Iower jadeite and grossular components. Also these systematic chemical variations in eclogites, clinopyroxenes, and garnets may be due to crystallization of picritic magma at high pressures; earlier crystallization products correspond to eclogites having lower p\"z+1Mgf Fe2+) ratios and lower jadeite and lower grossular components.

A case of glucocorticoid-responsive hyperaldosteronism.

Abstract: We have studied a 17-yr-old girl with hypokalemia, increased aldosterone production and suppressed plasma renin activity. Adrenal exploration revealed bilateral marked hyperplasia of the zona fasciculata and reticularis. Extirpation of the left adrenal and half of the light did not affect the hypertension, hyperaldosteronism, or hypokalemia. Dexamethasone, 2 mg/day for 2 weeks, produced normal blood pressure and serum potassium concentration. The hormonal studies showed: 1) increase in aldosterone and corticosterone secretion rates; 2) decrease in cortisol secretion and low-normal urinary excretion of 17-OHCS; 3) increase in urinary pregnanediol excretion in contrast to low-normal pregnanetriol excretion; 4) elevated plasma ACTH and a distinct increase of desoxycorticosterone secretion rate in response to metyrapone compared with a poor response of urinary 17-OHCS. These results suggest that the patient may have a partial defect of 17α-hydroxylation in the adrenal.

An Autoclavable Powdered Culture Medium for Mammalian Cells

Abstract: SummaryAn autoclavable powdered tissue culture medium could be successfully prepared by applying its thermostability in acidic pH. The formula of the medium is modified from Eagle MEM so as to be autoclaved at pH 4-4.5. The medium can be used not only for the cloning culture of established cell lines but also for the primary cultures of various mammalian cells.

Mitosis of heart muscle cells in normal rats.

Abstract: In order to demonstrate mitotic figures of the heart muscle cells and the interstitial cells during normal growth, colchicine was given to a total of 20 rats of various ages and mitosis in the myocardial cells was evaluated. The mitotic rate of heart muscle cells in 4 hours was 1.9-2.1% on the first day of life and it gradually decreased to 0.1% in 4 weeks and zero thereafter. The mitotic rate of interstitial cells was 2.0-2.2% on the first day of life and it similarly decreased to 0.1% in 6 months. These results seem to support our view that heart muscle cells and interstitial cells divide and increase in number with postnatal growth of the heart.

The electronic structures and spectra of nonbenzenoid aromatic hydrocarbons containing the cyclopropenyl ring

Abstract: The ground-state electronic properties and electronic spectra of triafulvene, I, triafulvalene, II, calicene, III, heptatriafulvalene, IV, benzocalicene, V, and dibenzocalicene, VI, have been studied by the semiempirical SCF CI LCAO-π-MO method which allows for bond order-bond length correlation at each iteration. The dependence of the resonance integral on bond length is scrutinized by trying to reproduce the properties of the ground and excited states in a series of reference compounds. For the bonds in the cyclopropenyl ring a new bond order-bond length relationship is proposed which allows for the fact that their σ components are bent. The calculated dipole moment and bond lengths of III and the predicted electronic spectra of III, V, and VI are in good agreement with the available experimental data.

Myocardial Structure and Vascularization of Hypertrophied Hearts

Abstract: The growth of the coronary artery and the myocardial capillarization in hypertrophied hearts were quantitatively evaluated in reference to myocardial volume. In concentric hypertrophy the mean blood flow per unit volume of the heart muscle estimated by the anatomical radii of the three major branches of coro-nary arteries was practically the same as that in the normal heart. A harmonious growth of the coronary artery with increasing myocardial volume was accordingly concluded. The often asserted view that hypertrophied hearts are subject to coronary insufficiency on account of undergrowth of coronary arteries inherent to cardiac hypertrophy was not supported. The total capillary length was found increased in hypertrophied hearts in parallel with the increase of the total surface area of the muscle fibers. However, the capillary length per unit volume of the heart muscle was reduced in hypertrophied hearts. Histometrical treatments revealed that the configuration of individual heart muscle fibers in concentric hypertrophy was geometrically similar to that in the normal heart. The behavior of the muscle fiber was essentially the same in dilata-tory hypertrophy too, although the growth in length predominated over that in breadth in a small number of cases. A growth in breadth of the muscle fibers not accompanied by one in length did not take place even in concentric hypertrophy. The difference of concentric and dilatatory hypertrophies was sought consequently in different structural arrangement and not in the shape of heart muscle fibers in the myocardial layer.

Ordered Arrangement of Oxygen in the Interstitial Solid Solution of Zirconium Oxygen System

Abstract: The crystal structure of interstitial solid solution of zirconium-oxygen system was investigated by means of X -ray, electron and neutron diffraction on specimens in the composition range between 11 and 27 at% 0. The specimens were prepared by melting appropriate mixtures of zirconium metal and zirconium dioxide in an arc-furnace. In addition to a superstructure found by Holmberg and Dagerhamn in the composition ZrO y (0.33< y <0.40), a new superstructure having a different ordered arrangement of oxygen was found in the range of ZrO x (0.25< x <0.33). The atomic arrangement of oxygen in these superstructures can be expressed in terms of the stacking sequence of octahedral interstitial sites in the lattice of α-Zr, i.e. , ABCABC … and ABAB … stackings in ZrO x and ZrO y respectively. However, the limiting composition ZrO 0.333 has an intermediate structure in which the arrangement of oxygen atoms is basically described as ABCBCACAB … stacking with nine layers period. The actual distribution of oxygen in sp...

Estimation of the cell number of heart muscles in normal rats.

Abstract: The total number of heart muscle cells of rats was estimated by a histometrical method. It was approximately 5 millions immediately after birth and rapidly increased to over 19 millions in the first month of life. Then it gradually increased to 20-22 millions by the age of 2 years. The total number of interstitial cells was approximately 3.5 millions immediately after birth, and increased progres-sively to 28 millions in a month, to 68 millions in a year and to 72 millions in 2 years. The number of heart muscle cells per 1mm3 of heart muscle was approximately 330, 000 immediately after birth and decreased with growth to about 1/9 of the initial number in 2 years. It was concluded that the heart muscle cells as well as the interstitial cells increased by cell division even after birth, and that the heart muscle cells not only increased in number, but also grew in size during the normal growth of the organ.