Showing papers by "Tohoku University published in 1978"
519 citations
TL;DR: In this paper, the dominance of matter over antimatter in the present universe is a consequence of baryon-number nonconserving reactions in the very early fireball, and a computation in specific SU(5) models gives a small ratio of Baryon to photon-number density in rough agreement with observation.
Abstract: I suggest that the dominance of matter over antimatter in the present universe is a consequence of baryon-number--nonconserving reactions in the very early fireball. Unified gauge theories of weak, electromagnetic, and strong interactions provide a basis for such a conjecture and a computation in specific SU(5) models gives a small ratio of baryon- to photon-number density in rough agreement with observation.
439 citations
TL;DR: A double-planed structure of deep seismic zone has been found over a wide area more then 300 km × 200 km in the Tohoku District, the northeastern part of Honshu, Japan.
417 citations
TL;DR: In this article, the structure of polycarbosilane is concluded to be similar to that of polysilapropylene by the measurements of i.r. spectra, NMR spectra and chemical analyses.
Abstract: Polycarbosilane as the precursor of continuous SiC fibre was synthesized by thermal decomposition of polydimethylsilane. The structure of the polycarbosilane is concluded to be similar to that of polysilapropylene by the measurements of i.r. spectra, NMR spectra and chemical analyses. Its formation mechanisms are initially the formation of carbosilane by thermal decomposition of polydimethylsilane and then the increase in molecular weight by dehydrogenation-condensation of the carbosilane. Molecular structure and molecular weight distribution of the polycarbosilane depend on the reaction temperature.
398 citations
TL;DR: In this article, a new method of synthesizing polycarbosilane at normal pressure by adding several wt % of polyborodiphenylsiloxane6 to polydimethylsilane was developed.
Abstract: THE high tensile strength SiC fibre developed in our laboratory1–5 is extremely heat-resistant and its wettability by metals is good. Metal–matrix composites reinforced with the SiC fibre should therefore be of practical use. Polycarbosilane, the precursor of the fibre, is synthesised by thermal decomposition under high pressure of poly dimethylsilane in an autoclave. To produce the SiC fibre on an industrial scale, polycarbosilane needs to be produced in large quantities with high yield. The autoclave method requires a large amount of space, so the operation is inconvenient and uneconomic. We have, therefore, developed a new method of synthesising the polycarbosilane at normal pressure by adding several wt % of polyborodiphenylsiloxane6 to polydimethylsilane. The structure and properties of the new polycarbosilane, and the SiC fibre obtained from it are described here.
338 citations
TL;DR: In this article, it was shown that the eddy viscosity for very stable conditions does not take the infinitesimally small value predicted from extrapolation of the so-called log-linear profile, and that the flux Richardson number has a limit in the range of 0.1-0.4, although the gradient Richardson number can become indefinitely large.
Abstract: Transfers of heat and momentum under strongly stable conditions in the atmospheric boundary layer have been studied through measurements of the turbulent fluctuations and vertical mean profiles of wind velocity and air temperature. As the local gradient Richardson number increases, intermittent turbulence appears, especially in temperature fluctuations. The ratio of the eddy conductivity to the eddy viscosity decreases with increasing Richardson number and tends to zero at high stabilities. The local value of the dimensionless shear function for wind velocity does not exceed a limit of about six. These results imply that the eddy viscosity for very stable conditions does not take the infinitesimally small value predicted from extrapolation of the so-called log-linear profile, and that the flux Richardson number has a limit in the range of 0.1–0.4, although the gradient Richardson number can become indefinitely large. It is also shown that the divergences of both the radiative and turbulent heat f...
301 citations
TL;DR: In this paper, a Co-Cr recording film with perpendicular anisotropy has been developed by an RF sputtering, which is found to show some suitable properties for high density recording such as a rectangular M-H loop, and fine grain structure.
Abstract: For a new perpendicular magnetic recording system, a Co-Cr recording film with perpendicular anisotropy has been developed by an RF sputtering. The Co-Cr films are found to show some suitable properties for high density recording such as perpendicular anisotropy, a rectangular M-H loop, and fine grain structure. An extremely high recording density of 100,000 bits/inch was realized by using the Co-Cr film. The crystal and microscopic structure of the films are also discussed, and the perpendicular anisotropy of the Co-Cr films is mainly originated from the uniaxial magneto-crystalline anisotropy.
298 citations
262 citations
TL;DR: In this article, the composition and structure of passive films formed on a series of iron-chromium alloys in de-aerated 1M H 2 SO 4 were quantitatively studied.
235 citations
TL;DR: The data support the hypothesis that an increase in the rate of intraruminal production of volatile fatty acids promotes proliferation of epithelial cells of the organ.
221 citations
TL;DR: In this paper, the location of the upper boundary of the descending slab was determined from the difference in arrival time between the ScS and ScSp waves, and it was shown that the boundary lies exactly on the upper plane of the double-planed deep seismic zone found in the Northeastern Japan Arc.
Abstract: Summary. The ScSp wave converted from the ScS wave at the boundary between the descending lithospheric slab and the mantle above it was clearly observed from a nearby deep earthquake with magnitude 7.7 at some stations of the seismic network of Tohoku University which covers the Tohoku District, the northeastern part of Honshu, Japan. By applying the threedimensional seismic-ray tracing method, the location of this boundary was determined from the difference in arrival time between the ScS and ScSp waves. The result shows that the upper boundary of the descending slab lies exactly on the upper plane of the double-planed deep seismic zone found in the Northeastern Japan Arc. There is an additional evidence that the boundary is located on the upper plane of the double-planed deep seismic zone. The hypocentre distribution of intermediate-depth earthquakes located by the small-scale seismic-array observation is extremely different from that obtained by the relatively largescale seismic network. The discrepancy in the distribution of hypocentres of the same earthquake independently located is well explained by the inclined lithospheric slab model derived from the difference in arrival time between the ScS and ScSp waves. The earthquakes with reverse faulting or with down-dip compressional stresses occur at the upper boundary of the descending slab. Within the descending slab, the earthquakes with down-dip extensional stresses also occur in a very narrow zone from 30 to 40 km below the dipping boundary in the depth range from 50 to about 200 km, and these shocks form the lower plane of the double-planed deep seismic zone.
TL;DR: The fabrication of a microprobe for simultaneous, independent and in-vivo measurements of H+ and Na+ ion activities is described.
Abstract: The fabrication of a microprobe for simultaneous, independent and in-vivo measurements of H+ and Na+ ion activities is described.
TL;DR: A rapid, simple, and accurate method for the chemical assay of angiotensin-converting enzyme has been developed that relies on the use of 2,4,6-trichloro-s-triazine (TT) as a colorimetric reagent of hippuric acid (N-benzoylglycine).
TL;DR: The present method is applicable to quantitation of free and conjugated bile acids in human bile with satisfactory accuracy and precision.
TL;DR: In this article, the interdiffusion coefficients in Al-Si alloys were determined by Matano's method in the tem-perature range from 753 to 893 K with the couple consisting of pure aluminum and an Al- Si alloy.
Abstract: Interdiffusion coefficients in Al-Si alloys were determined by Matano’s method in the tem-perature range from 753 to 893 K with the couple consisting of pure aluminum and an Al-Si alloy. Temperature dependence of the impurity diffusion coefficients of Si in Al, obtained by extrapolation of the concentration dependence of the interdiffusion coeffi-cient to zero mole fraction of Si, is given by the following equation: DSi/Al = (2.02+0.97
-0.66 × 10-4 exp [-(136 ±3) kJ mol-1/RT] m2/s. p ] The Kirkendall marker was found to move toward the Si-rich side, indicating that the Si atom diffuses faster than the Al atom in Al-Si alloys. From the interdiffusion coeffi-cient and the marker shift, the intrinsic diffusion coefficients were calculated. The difference in the activation energies (ΔQ) between the impurity diffusion of Si in Al and the self-diffusion of Al was estimated by means of the asymptotic oscillating po-tential and the Le Claire theory. The calculated value of ΔQ is in fair agreement with the experimental value. The vacancy-solute binding energy for Si in Al was also dis-cussed based on the diffusion data.
TL;DR: This paper investigates experimentally the change of the refractive index, due to forces such as pulling and pure bending, in an optical fiber fabricated by the CVD technique, and finds that this phenomenon can be interpreted in terms of a simple model of the fiber, that is, a mechanically homogeneous circular rod.
Abstract: This paper investigates experimentally the change of the refractive index, due to forces such as pulling and pure bending, in an optical fiber fabricated by the CVD technique. It is found that this phenomenon can be interpreted in terms of a simple model of the fiber, that is, a mechanically homogeneous circular rod. We compare the effect of the refractive-index change and that of a geometrical deformation of the fiber on transmission characteristics. A new method based on photoelasticity is also proposed to measure the curvature distribution of a fiber whose axis is deformed by external forces.
TL;DR: The integrity of microsomal membrane was destroyed by storage at −25°C, when activity of G6Pase in the patient's liver could be demonstrated, and this may be the first example of a disorder involving the transport system of an intracellular membrane.
TL;DR: Early operation, adequate surgical technique, and prevention of postoperative cholangitis are requisites for successful hepatic portoenterostomy.
Abstract: Intrahepatic bile ducts are patent in the liver of patients with biliary atresia in early infancy. Small bile ducts at the porta hepatis continuing to the intrahepatic ducts usually terminate in fibrous tissue replacing the hepatic radicles, which does not extend to the common hepatic duct. Therefore, the level of transection of the fibrous tissue at the porta hepatis is of prime importance for successful hepatic portoenterostomy. Transection should be done at the level of the posterior surface of the portal vein. The overall cure rate of surgery for biliary atresia was 30%. In our recent series, however, the results have markedly improved and the cure rate has been increased to 55%. There are 47 patients living without jaundice, 22 of them for more than 5 years. The longest survivors are 23 years old. All the longterm survivors are leading a normal life for their age, although 6 of them have some physical or mental handicap. Early operation, adequate surgical technique, and prevention of postoperative cholangitis are requisites for successful hepatic portoenterostomy.
01 Jan 1978
TL;DR: A detailed metamorphic zonal mapping is being conducted on the Sanbagawa belt in central Shikoku as mentioned in this paper, where a large scale recumbent fold, with south vergency and extending for more than 20km, is postulated as a possible structural interpretation.
Abstract: A detailed metamorphic zonal mapping is being in progress on the Sanbagawa metamorphic belt in central Shikoku. The mapping is based upon the distribution of index minerals, garnet and biotite in pelitic schists, and on the sliding equilibrium among silicate and oxide minerals. The distribution of mineral zones has revealed a peculiar thermal structure of the metamorphic complex that the highest-grade rocks occur in the middle of apparent stratigraphy. A large scale recumbent fold, with south vergency and extending for more than 20km, is postulated as a possible structural interpretation.It is concluded, as the most probable model we could imagine at the moment, that before the maximum temperature of metamorphism was reached, the Sanbagawa schists had been metamorphosed in more or less normal thermal regime that the temperature had increased downwards. Then a large scale recumbent fold took place, separating the higher-grade rocks from the heat source and bringing them in between the lower-grade ones. This recumbent fold was accompanied by the start of the uplift of the whole metamorphic complex, while continuing metamorphic reactions with decreasing temperature and pressure.The fact that the Sanbagawa belt is overturned suggests that a very distinctive crustal shortening took place in the present day Sanbagawa terrain in the Mesozoic time, and that the present day distribution of pre-Tertiary geologic units in the outer zone of the south-western Japan can hardly be in situ.
TL;DR: Evidence for a new hepatitis-specific antigen has been obtained from double immunodiffusion assays between acute and convalescent sera obtained from patients with non-A, non-B post-transfusion hepatitis, and the designation hepatitis C (HC) antigen is proposed.
TL;DR: In this article, the change of variable method introduced by Landau for the one-dimensional problem is extended to the multi-dimensional using an independent variable which takes constant values at the boundary and the freezing front.
Abstract: This paper presents a simple numerical method for solving two and three-dimensional freezing problems with arbitrary geometries. The change of variable method introduced by Landau for the one-dimensional problem is extended to the multi-dimensional using an independent variable which takes constant values at the boundary and the freezing front. Example calculations were performed for the Stefan type freezing problem in regular squares, triangles, and ellipses. Then some of the results were compared with the experimental ones that were obtained for the constant cooling rate.
TL;DR: In this paper, the corrosion and electrochemical properties of amorphous iron-chromium alloys containing different sets of glass-forming metalloidal elements, boron, carbon, silicon and phosphorus, have been investigated.
Abstract: Corrosion and electrochemical behaviours of amorphous iron-chromium alloys containing different sets of glass-forming metalloidal elements, boron, carbon, silicon and phosphorus, have been investigated. The corrosion resistance in 0.1N H2SO4 increases in the order of alloys containing silicon, boron, carbon and phosphorus, and the corrosion resistance in 3% NaCl increases in the order of alloys containing boron, silicon or carbon, and phosphorus. Difference in the corrosion resistance of amorphous alloys containing various metalloids has been interpreted in terms of the difference in the formation rate of the chromium-enriched protective film on the surface of alloys.
TL;DR: In this article, the absolute Raman intensities of methanol, ethanol and water in the gas and liquid phases have been measured using 514.5 and 337.1 nm excitation.
Abstract: The absolute Raman intensities of methanol, ethanol and water in the gas and liquid phases have been measured using 514.5 and 337.1 nm excitation. Large intensity changes were observed for the Raman lines of the OH stretching vibrations in changing from gas to liquid. The observed intensity changes are interpreted as due to the additional contribution of the charge transfer electronic excited state arising from hydrogen bond formation. The Raman intensities of methanol, ethanol and water in alkali halide solutions were also studied. The observed effects of halide ions on the intensities and their excitation wavelength dependences were found to be well correlated with the known charge transfer states resulting from electron transfer from the halide ion to the surrounding solvent molecules.
TL;DR: In this article, a review of the studies on these pulsations putting a stress on Pi3 is presented, and a stress is further laided on morphology and theory of the Ps6-type Pi3 pulsation.
Abstract: In the 1973 Scientific Assembly, the International Association of Geomagnetism and Aeronomy proposed with Resolution No. 11 to settle two new classes of magnetic pulsations; Pc6 having a sinusoidal waveform with periods longer than 600 s and Pi3 having an irregular waveform with periods longer than 150 s. The present paper reviews the studies on these pulsations putting a stress on Pi3. the Pi3-type pulsations are further classified into Psc5, Psc6, Pip, Ps6 and another type. The pulsations Psc5 and Psc6 mean the damped-type pulsations associating with storm sudden commencement in the approximate period range from 150 to 600 s and longer than 600 s, respectively, while Pip and Ps6 are the quasi-sinusoidal pulsations associating with magnetospheric substorm in the appropriate period range from 100 to 400 s and from 5 to 40 min, respectively. In the present review paper a stress is further layed on morphology and theory of the Ps6-type Pi3 pulsation. The following two-snake model is concluded to be plausible. A current system with in-flowing field-aligned current, westward ionospheric current, and out-flowing field-aligned current expands toward both the dawn- and the dusk-sectors with the progress of magnetospheric substorm. Thus Ps6 is regarded to be due to a magnetic effect of a meandering of the current system during the expansion, which is compared with the meandering of two snakes along the auroral oval from the midnight point toward both the east and the west, respectively.
TL;DR: Seven pancreases from nondiabetic autopsy cases were submitted to morphometrical analysis of the islets of Langerhans as a preliminary investigation of the diabetic pancreas, and the islet distribution appeared to change the pattern gradually according to the position from the pancreatic head to the tail.
Abstract: Seven pancreases from nondiabetic autopsy cases were submitted to morphometrical analysis of the islets of Langerhans as a preliminary investigation of the diabetic pancreas. The pancreatic islets were approximately simulated by spheres of different sizes randomly dispersed in the three-dimensional space; thereon the parameters of Weibull function assumed for the distribution of islet radii were estimated stereologically from chord length measurements on histologic sections taken from different portions of the pancreas. By means of the estimated parameters topographical comparison of the number, volume, mean radius and size distribution of islets in a unit volume were performed. This islet distribution appeared to change the pattern gradually according to the position from the pancreatic head to the tail: the head was characterized by abundance of small islets that corresponded to a slightly higher islet population threat, whereas the tail by moderate increase of larger islets that caused a steep increase of islet volume here. To estimate parameters for the whole pancreas a histologic section from a range between the midposition of the pancreas and the one-fourth position from the splenic end was regarded to be a fairly good representative.