Showing papers by "Tohoku University published in 1977"
TL;DR: A statistical model, based on extensive experimental data, was established to characterize the urban radio propagation medium in various urban environments and the peaks of the multipath response were analyzed statistically concerning the distribution of the path strength and the path arrival time.
Abstract: A statistical model, based on extensive experimental data, was established to characterize the urban radio propagation medium in various urban environments. Describing the medium by a linear filter, the peaks of the multipath response were analyzed statistically concerning the distribution of the path strength and the path arrival time. The statistical properties of these quantities depend on the modulation delay time. The resulting model can be used for simulation experiments in order to avoid costly hardware tests of ad hoc systems.
1,013 citations
TL;DR: In this paper, a new perpendicular magnetic recording system is proposed for high density recording, which uses the perpendicular magnetization mode which is basically free from the demagnetization in very high densities.
Abstract: By the analysis of the self-consistent magnetization and the direct observation of the remanent magnetization of a real tape, the authors discussed the obstacles which are, and will be, encountered in attaining a higher recording densities with the present magnetic recording system, which uses mainly a longitudinal magnetization mode. Then the properties of the three magnetization modes (longitudinal, circular, and perpendicular) are compared. The mode transformation is also discussed. Finally a new perpendicular magnetic recording system is proposed for high density recording. And some results of fundamental experiments are presented. The system uses the perpendicular magnetization mode which is basically free from the demagnetization in very high densities. Its realization mainly owes to the development of a perpendicular anisotropy film and perpendicular magnetic heads.
463 citations
TL;DR: In this article, the peak binding energies of 2p, 3s and 3p electrons of Fe and Cr in the X-ray photo-electron spectra of Fe2O3, Fe3O4, α-FeOOH, γ-FeOH, Cr2O 3, Cr(OH)3· 0·4H2O and CrO3 were measured.
440 citations
TL;DR: In this article, the compositions of the alloy surface and the surface oxide on mechanically polished iron-chromium alloys were studied using the XPS technique, and the results showed no enrichment of chromium or iron either in the oxide layer or the Alloy surface.
327 citations
TL;DR: In this paper, the composition of spinel Iherzolites has been studied and it is suggested that the compositions of spinels represent both undepleted and depleted compositions, and a representative composition for the primitive mantle is proposed on this basis.
Abstract: The compilation of analyses of continental and oceanic spinel Iherzolites show that these two types of Iherzolites have very similar compositions. Their composition range differ from that of African garnet Iherzolites, and the data suggest that the mantle beneath Africa has an anomalous composition. If the composition of the upper mantle may be estimated from that of Iherzolites, the compositions of spinel Iherzolite should form the basis for this estimate. It is suggested that the compositions of spinel Iherzolite represent both undepleted and depleted compositions, and a representative composition for the primitive mantle is proposed on this basis.
312 citations
TL;DR: In this paper, anodic polarization curves, ac electrode impedances, ellipsometric parameters and X-ray photo-electron spectra have been measured on the Mo-containing steels passivated in 1N HCl.
304 citations
TL;DR: The recovery of immuno-properties from the individual subunits may be attributed to the reconstruction of the three-dimensional structure upon removal of denaturing reagents.
205 citations
TL;DR: In this paper, the Stoner boundary energy decreases with increasing temperature and collapses into critical scattering above 40 K. At 5 K in a magnetic field of 10 kOe, well defined spinwave excitations have been observed below 2.5 meV.
Abstract: Magnetic excitations in an intermetallic compound MnSi have been studied by neutron scattering. At 5 K in a magnetic field of 10 kOe, well-defined spin-wave excitations have been observed below 2.5 meV. The dispersion relation is almost isotropic and is $h{\ensuremath{\omega}}_{q}(\mathrm{meV})=0.13+52{q}^{2}$ (${\mathrm{\AA{}}}^{\ensuremath{-}2}$) in the [100] direction. Above 3 meV, the excitation linewidth increases substantially, suggesting that the dispersion relation merges into the Stoner continuum. The Stoner excitations, which extend over almost all of the Brillouin zone, show a broad peak on the extension of the spin-wave dispersion relation. The spin-wave excitation renormalizes with increasing temperature and collapses into critical scattering above 40 K. On the other hand, the excitation in the Stoner continuum is affected little by temperature; the excitations are qualitatively the same at $\frac{T}{{T}_{N}}=10$ as at 5 K. The Stoner boundary energy decreases with increasing temperature. The results provide us with the first example of magnetic excitations in a weak itinerant ferromagnet.
193 citations
TL;DR: In this paper, a supplement to Blum's theory for asymmetric electrolytes is presented. But it does not address the problem of asymmetric electrophoresis, and it cannot explain the asymmetric EH.
Abstract: (1977). Supplement to Blum's theory for asymmetric electrolytes. Molecular Physics: Vol. 33, No. 4, pp. 1195-1198.
187 citations
TL;DR: In this article, various adiabatic approximations are defined in an effort to remove the existing ambiguities and various approaches for improving approximate wave functions to obtain more exact wavefunctions are discussed.
Abstract: — The term usually referred to as vibronic coupling is discussed. Various adiabatic approximations are exactly defined in an effort to remove the existing ambiguities. The various approaches for improving approximate wavefunctions to obtain more exact wavefunctions are discussed. Transition dipole moments between two vibronic states are evaluated by the different methods, and the mutual relationship among the methods is discussed.
153 citations
TL;DR: In this paper, measurements of magnetization, electrical resistivity, thermal expansion and differential thermal change were made on amorphous Fe 100-x B x (9 ≦ X ≦ 21) alloys prepared by rapid quenching from the liquid state.
TL;DR: In this article, the Raman spectra of ZrO/sub 2/ were measured in the range 300 to 1600/sup 0/K. The temperature dependence of the spectra shows a hysteresis.
Abstract: Raman spectra of ZrO/sub 2/ were measured in the range 300 to 1600/sup 0/K. Irreducible components of the Raman spectra were obtained from polarization measurements at room temperature, and the symmetries of the Raman-active modes in the monoclinic phase were determined. The temperature dependence of the spectra shows a hysteresis. In the temperature range of phase change, two kinds of Raman lines coexist. Six Raman-active mode frequencies were found in the tetragonal phase at high temperatures. Analysis of the spectra showed that the Raman-active modes in the tetragonal phase are affected by strain introduced into the crystals during the phase transformation.
TL;DR: In this paper, the maximum stable drop size was derived theoretically, by taking into consideration the effect of the dispersed-phase viscosity, and the derived formula indicated that the controlling factors of the maximum standing drop size are the Weber Number and the visco-group which is defined as the ratio of the viscous stress to the stress of interfacial tension.
Abstract: A formula for the maximum stable drop size has been derived theoretically, by taking into consideration the effect of the dispersed-phase viscosity. The derived formula indicates that the controlling factors of the maximum stable drop size are the Weber Number and the viscosity group which is defined as the ratio of the viscous stress to the stress of interfacial tension. The validity of the formula was confirmed experimentally over a wide range of dispersed-phase viscosity.
TL;DR: In this paper, a search for growth and germination inhibitors in rice husk (Oryza sativa L. cv Koshihikari) revealed four compounds, ineketone, S (+)-dehydrovomifoliol, momilactone-C and p -coumaric acid, in addition to the previously known motherilactones-A and -B.
TL;DR: It is suggested that furosemide enhances urinary excretion of prostaglandin E by mechanisms which entails either an increase in prostaglandsin synthesis or a decrease in renal metabolism.
TL;DR: It is postulated that the S-allele produces several fractions of proteins and S.allele specificity is expressed by a combination of the protein fractions.
Abstract: Analysis of S-specific proteins in stigma of Brassica oleracea L. by isoelectric focusing
TL;DR: Characteristic early lesions of congenital amaurosis appeared to be produced by deposits consisting of loose outer segments and apical processes of the pigmental epithelial cell and macrophages.
TL;DR: The number of epidermal melanocytes positive to the dopa reaction increased when skin explants from newborn mice were cultured with MSH or dbc-AMP as discussed by the authors, suggesting that the initiation of melanogenesis requires de novo transcription and translation.
Abstract: The number of epidermal melanocytes positive to the dopa reaction increased when skin explants from newborn mice were cultured with MSH or dbc-AMP. These agents seem to induce melanogenesis in the pre-existing melanoblasts. This hormone-induced melanogenesis is suppressed by actinomycin D or cycloheximide, suggesting that the initiation of melanogenesis in the epidermal melanoblasts requires de novo transcription and translation.
TL;DR: In this paper, the energy band structures of Gd-pnictides, GdX(X=N, P, As and Sb), known to show a transition from a semiconductor to a metal in the series from GdN to GdSb, are calculated using the APW method.
Abstract: Energy band structures of Gd-pnictides, GdX(X=N, P, As and Sb), known to show a transition from a semiconductor to a metal in the series from GdN to GdSb, are calculated using the APW method It is found that the energy bands depend sensitively on a choice of the one-electron potential Then, the calculation is carried out self-consistently The calculated bands account qualitatively well for the observed trend of the conducting properties through the pnictides The density of states agrees reasonably well with experimental results The Fermi surface of metallic pnictides is calculated both for paramagnetic and ferromagnetic states It consists of simple closed electron and hole surfaces Relativistic effects are investigated using first-order perturbation theory They do not affect seriously nonrelativistic bands
TL;DR: In this article, the partial structure factors of a binary metallic glass are given based on the experimental data, and various characteristics such as crystallization processes, thermal effects and alloying effects are also discussed.
Abstract: An attempt has been made in this review to cover recent information on the structure of metallic glasses (amorphous metals) obtained by X-ray diffraction. Based on the experimental data, the partial structure factors of a binary metallic glass are given. Various characteristics such as crystallization processes, thermal effects and alloying effects are also discussed.
TL;DR: In this paper, nine transition metals in Group VIII were examined as catalysts for the carbon gasification with steam, carbon dioxide and hydrogen metal-doped carbons were heated up to 950°C at a constant rate of 200°C/hr in a flowing reactant gas.
TL;DR: In this paper, the properties of a mixture of two anisotropic antiferro-magnets with different easy axes have been analyzed both in mean field approximation and in the method of distribution function.
Abstract: Thermal and magnetic properties of a mixture of two anisotropic antiferro-magnets with different easy axes have been analyzed both in mean field approximation and in the method of distribution function. A new phase called OAF phase is found within a certain range of concentration. In OAF phase, the spin of each species of ion on a sublattice has each own axis of sublattice magnetization tilting oblique to the easy axes of the pure systems. As temperature increases, OAF phase makes a transition into the antiferromagnetic phase and then to the paramagnetic phase successively. It is expected that these transitions are detected by measurements of specific heats for a powder sample and of susceptibilities for a single crystal. It is also pointed out that magnetization processes show some characteristic features of OAF phase.
TL;DR: The masseter fibres of the ruminant differed from those of the other species in histochemical properties, and appeared to have the histochemical characteristics that meed functional demands for slow, long-term exercise.
Abstract: The masseter muscles of different mammals were studied by means of histochemical reactions: NADH: Nitro BT oxidoreductase (NADHOX), 3-hydroxybutyrate: NAD+ oxidoreductase (HBOX), glycerol-3-phosphate: menadione oxidoreductase (GPOX), and acid-stable and alkali-stable myosin adenosine triphosphatase (ATPase). The masseter muscles of cattle and sheep consisted only of the fibres that reacted moderately for GPOX and strongly for NADHOX, HBOX, and the acid-stable ATPase. The masseter fibres of rats and guinea pigs reacted uniformly and strongly for GPOX and the alkali-stable ATPase. The fibres of the rats showed a weak to strong reaction for NADHOX and mostly a negative reaction for HBOX, whereas those of the guinea pigs reacted uniformly and strongly for NADHOX and HBOX. The masseter fibres of swine and dogs showed a weak or strong reaction for the alkali-stable and a negative or weak reaction for HBOX. The fibres of the swine were weak to strong in NADHOX activity and those of the dogs uniformly strong; the fibres of the two species gave a moderate to strong reaction for GPOX. The masseter fibres of the ruminant differed from those of the other species in histochemical properties, and appeared to have the histochemical characteristics that meed functional demands for slow, long-term exercise.
TL;DR: In this article, a multi-element polyborodiphenylsiloxane containing oxygen (B, C, Si, O, H) was compared with PC composed of Si, C and H, and observed the process of its thermal decomposition.
Abstract: WE have previously reported successful production of a high-strength continuous SiC fibre1–3, a high flexural strength SiC sintered body4 and a heat-resistant Fe–Cr alloy5 by converting organometallic polymer polycarbosilane (PC) as the binder to an inorganic in thermal decomposition. We then found that in the thermal decomposition of organometallic polymers such as PC, an amorphous state exists before formation of the (SiC) fine particles; this SiC amorphous state is hardly possible in inorganic reactions. The process of thermal decomposition of organometallic polymers is little known. To obtain general information on the phenomenon, we have newly synthesised multi-element polyborodiphenylsiloxane containing oxygen (B, C, Si, O, H) compared with PC composed of Si, C and H, and observed the process of its thermal decomposition.
TL;DR: The mode of generation of free radicals of daunomycin, adriamycin, and carboquone in the NADPH-rat liver microsome system was studied at room temperature by electron spin resonance (ESR) spectroscopy and there were differences in the mode of their generation.
Abstract: The mode of generation of free radicals of daunomycin, adriamycin, and carboquone in the NADPH-rat liver microsome system was studied at room temperature by electron spin resonance (ESR) spectroscopy. ESR signals of all these quinoid anticancer chemicals were detected when dissolved oxygen in the reaction mixture was consumed since the radicals are easilyaut oxidizable. All the radicals had an appreciable lifetime under anaerobic conditions. However, there were differences in the mode of their generation between daunomycin and adriamycin, on the one hand, and carboquone, on the other, with respect to the lag time and the effect of the amount of chemicals, pH of the medium, kind of electron donors, NADPH and NADH, and the presence of excess of DNA. Especially, ESR signal reappeared after the first signal had decreased considerably, in the case of daunomycin and adriamycin but not in carboquone. Intact Ehrlich ascites tumor cells also gave rise to an ESR signal of adriamycin and carboquone, but the former signal was prevented from appearing in the presence of glucose.
TL;DR: A time-of-flight pulsed neutron diffractometer for the measurement of liquid and amorphous structures was built using a pulsed neut source installed at the Tohoku University 300 MeV electron linac.
TL;DR: Glycogen synthase D was prepared from rat liver by chromatographing the glycogen pellet on DE-52 columns by means of column chromatography and, under the conditions developed, synthase phosphatase emerged from the columns as a sharp, single peak, and phosphorylaseosphatase came off later.
TL;DR: In this article, the authors analyzed and presented an example representing the structure of a growing wind-wave field using data collected at the Shirahama Oceanographic Tower Station, Kyoto University, obtained in November 1969.
Abstract: Observational data on air-sea boundary processes at the Shirahama Oceanographic Tower Station, Kyoto University, obtained in November, 1969, was analyzed and presented as an example representing the structure of growing wind-wave field. The condition was an ideal onshore wind, and the data contained continuous records of the wind speed at four heights, the wind direction, the air and water temperatures, the tides, and the growing wind waves, for more than six hours. The main results are as follows. Firstly, in both of the wind speed and the sea surface wind stress, rather conspicuous variations of about six-minute period were appreciable. Secondly, the three-seconds power law and its lemma expressed byH*=BT*3/2 andδ=2πBT*−1/2, respectively, are very well supported by the data, whereH*(≡gH/u*2) andT*(≡gT/u*) are the dimensionless significant wave height and period, respectively,δ the wave steepness,u* the friction velocity of air,g the acceleration of gravity, andB=0.062 is a universal constant. Thirdly, the spectral form for the high-frequency side of the spectral maximum is well expressed by the form ofΦ(σ)=αsgu*σ−4, whereσ is the angular frequency andΦ(σ) the spectral density. The value ofαs is determined as 0.062±0.010 from the observational data. There is a conspicuous discrepancy between the spectral shape of wind waves obtained in wind-wave tunnels and those in the sea, the former containing well-defined higher harmonics of the spectral peak, and consequently there is an apparent difference in the values ofαs also. However, it is shown that the discrepancy ofσs may be eliminated by evaluating properly the energy level of the spectral form containing higher harmonics.