Showing papers by "Chiba Institute of Technology published in 1988"
TL;DR: In this article, an experiment experimentale on the alliages Al-7,9,9 a 9,7% at Li was conducted to determine the structures and the processus de mise en ordre.
Abstract: Etude experimentale sur les alliages Al-7,9 a 9,7% at Li. Observation directe des arrangements atomiques afin de determiner les structures des alliages et le processus de mise en ordre. Determination a partir de calculs d'images, des caracteristiques des images en haute resolution des structures ordonnees
29 citations
TL;DR: On definit une mesure floue comme une fonction ensemble μ sur #7B-F qui est une σ-algebre de sous-ensembles de l'ensemble X.
28 citations
TL;DR: In this article, the authors observed the layered structures of GP zones in high-resolution electron microscope images under optimum imaging conditions and found that the majority of the GP zones were typical GP(1) zones with a single-layer structure and typical multi-layer structures with a structure consisting of two Cu-rich layers separated by three Al layers.
28 citations
TL;DR: Hydroxy acids in sediments of Lakes Bonney, Fryxell, Joyce and Vanda, and unnamed ponds as well as in cyanobacterial mats from the McMurdo Sound region of southern Victoria Land in Antarctica have been studied to clarify their features and elucidate their source organisms.
25 citations
TL;DR: In this paper, it was shown that bis(diisopropylamino)-1,1, 1,3, 3, 3-hexafluoro-2-propoxyphosphine is easy to prepare in view of their stability during purification by distillation which not requires high vacuum.
19 citations
TL;DR: In this article, the structure and formation kinetics of GP zones in an Al-1.7 at. 298 K were investigated by the small-angle X-ray scattering technique of synchrotron radiation.
18 citations
TL;DR: In this article, the effect of radiation damage on neutron-transmutation-doped silicon of initially low- and high-resistivity materials has been studied by electrical property measurements, showing that the mechanism of carrier scattering is dominated by ionized impurities acting as point defects.
Abstract: The effect of radiation damage on neutron-transmutation-doped silicon of initially low- and high-resistivity materials has been studied by electrical property measurements. The materials were irradiated with a moderate thermal (0.45-1.0*1018 neutrons cm-2) and fast (0.45-8.1*1016 neutrons cm-2) neutron fluences. After irradiation, a small reduction of carrier mobility of the initially low-resistivity materials was observed, while the reduction of conductivity was large. The annealing behaviour and temperature dependence of mobility of the materials indicate that the mechanism of carrier scattering is dominated by ionised impurities acting as point defects. The conductivity of those materials was recovered after annealing at 560 degrees C for 60 min. In the range of annealing temperatures below 600 degrees C, the carrier mobility of initially high-resistivity materials decreased together with the conductivity. The last result can tentatively be explained by a defect cluster model for fast-neutron-induced lattice damage.
18 citations
TL;DR: In this article, the vertical distribution of trace elements in the three lakes of the Vestfold Hills was investigated, and three aspects were discussed as follows: (1) the vertical distributions of 18 trace elements, (2) the behaviour of trace element in the lakes, especially that of manganese in Shield Lake, and (3) the origin of trace items in antarctic saline lakes.
Abstract: The distributions of trace elements in Shield, Ace and Burton Lakes of the Vestfold Hills were investigated. Three aspects are discussed as follows: (1) the vertical distribution of 18 trace elements in the three lakes, (2) the behaviour of trace elements in the lakes, especially that of manganese in Shield Lake, and (3) the origin of trace elements in antarctic saline lakes.
17 citations
TL;DR: In this paper, the authors used multi-spacecraft observations in the interplanetary space to build up a picture of the distribution of solar wind velocities in heliographic latitude and longitude.
10 citations
TL;DR: In this paper, a kinetic model was developed for the performance of a CO laser, on which efficient extraction of laser power was obtained by exciting a subsonic gas mixture of CO/N2/He/O2 through transverse dc discharge.
Abstract: A kinetic model has been developed for the investigation of the novel performance of a CO laser, on which efficient extraction of laser power was obtained by exciting a subsonic gas mixture of CO/N2/He/O2 through transverse dc discharge. Kinetic equations for direct excitation by electron impact, V-V and V-R/T energy transfer, and stimulated emission are coupled with a semi-one-dimensional flow model. Careful consideration is devoted especially to the V-V transfer process of CO−N2 and N2−N2. The laser power was calculated by a constant gain method. The laser output performance, examined as a function of gas mixture ratio, temperature, flow velocity, and discharge current, was in good agreement with the experiment.
9 citations
TL;DR: In this article, the crystallization behavior of polyetheretherketone (PEEK) was investigated by differential scanning calorimetry (DSC) and double peaks in their DSC curves were found to be caused by the formation of incomplete crystal structures.
Abstract: The crystallization behavior of polyetheretherketone (PEEK) was investigated by differential scanning calorimetry (DSC). The glass transition temperature of PEEK shifts to higher temperatures with an increase in crystallinity. Heat-treated PEEK showed double peaks in their DSC curves, which is a characteristic phenomenon of PEEK. These double peaks were caused by the formation of incomplete crystal structures according to the conditions of heat-treatment.
Das Kristallisationsverhalten von Polyetheretherketon (PEEK) wurde mit Hilfe der Differentialkalorimetrie (DSC) untersucht. Mit der Erhohung der Kristallinitat verschiebt sich die Glastemperatur zu hoheren Temperaturen. Hitzebehandeltes PEEK zeigt Doppelpeaks in der DSC-Kurve, was fur PEEK charakteristisch ist. Diese Doppelpeaks werden, je nach den Bedingungen der Hitzebehandlung, durch die Bildung unvollstandiger Kristallstrukturen hervorgerufen.
TL;DR: In this paper, high conducting polymer films that are stable to ambient conditions and have good mechanical properties can be obtained by the electrochemical copolymerization of benzo[b]thiophene with pyrrole.
01 Jul 1988-Precision Engineering-journal of The International Societies for Precision Engineering and Nanotechnology
TL;DR: In this article, the diameters of molten particles ejected from the targets were obtained and the volume of solidified material remaining around the crater was also obtained, from these results, the proportion of molten material ejected from a target was determined.
Abstract: Crater formation in electron and laser beam drilling is mainly due to molten material removal. In this process, there are two different modes of removal: ejection outside the target and transport of material which remains around the crater on the target surface. Measurement of these removal modes was carried out. The diameters of molten particles ejected from the targets were obtained. Characteristic particle diameters were determined for each material and each drilling condition. The volume of solidified material remaining around the crater was also obtained. From these results, the proportion of molten material ejected from the target was determined. Most of the molten material remained around the crater for iron and tungsten, but was ejected outside the target for aluminium and alumina ceramics.
Abstract: Mechanical and dielectric strength were measured for three types of BaTiO3 thick films prepared under the different processing conditions. In any case, Weibull moduli for both strength distributions were identical in each type of films, though they differed among three types. The results indicated that dielectric strength measurement is a promising alternative method to distinguish the structural reliability change as influenced by processing parameters before firing within the framework of the same fabrication method.
TL;DR: In this paper, the effect of thermal history on the crystallization behavior of PEEK was investigated by the dynamic viscoelastometer, and it was suggested that the reduction in the storage modulus corresponds to some defect in the crystal structure of PEK.
Abstract: The effect of thermal history on the crystallization behaviour of PEEK is investigated by the dynamic viscoelastometer. The crystallization behaviour of PEEK shows significant influence on the α peak in the tan δ and the storage modulus. The α peak temperature is rapidly increased at shorter times with the annealing temperature at 160°C or higher, and is then constant. The storage modulus is more gently reduced in the α transition region as the annealing temperature is higher, and becomes then a constant value. It is suggested that the reduction in the storage modulus corresponds to some defect in the crystal structure of PEEK.
Der Effekt der thermischen Vergangenheit auf das Kristallisationsverhalten von PEEK wurde mit dem dynamischen Viskoelastometer untersucht. Das Kristallisationsverhalten zeigt deutliche Abhangigkeit von Tempertemperatur und Temperzeit und ausert sich im dynamischen Verhalten des PEEK.
TL;DR: In this article, the reaction behavior of CdS encapsulated copolymer (styrene-acrylonitrile copolymers; C-St · AN-CdS) composites, their photoconductivity, and the mechanism of their photosensitivity were investigated.
27 Jan 1988
TL;DR: Optical Heterodyne Fiber Gyro as mentioned in this paper has a wide dynamic range and a good linearity, but it has a relatively large zero-point drift induced mainly by thermal fluctuation of the acoustic-wave velocity in the Acousto-Optical Modulator.
Abstract: Optical Heterodyne Fiber Gyro[l,2], which we have proposed and experimented with, has a wide dynamic range and a good linearity. We demonstrated the rotation detection with 5 digits [1,2]. However, it has a relatively large zero-point drift induced mainly by thermal fluctuation of the acoustic-wave velocity in the Acousto-Optical Modulator (AOM) [1,2].
TL;DR: In this paper, the intensity and line width of scattered light from polystyrene solution in cyclopentane were measured near the lower critical solution temperature, and the dependence of line-width on temperature was found to be almost the same as those near the upper critical temperature.
TL;DR: In this paper, the effects of different B-site elements on the Curie points of the PbTiO3-Pb(M1/3Nb2/3)O3 and 0.99BaTiO03-0.01 Ba(M 1/3 Nb 2/3 )O3 series (M = Ca, Mn, Fe, Co, Ni, Cu, Zn).
Abstract: The effects of different B-site elements on the Curie points of the PbTiO3-Pb(M1/3Nb2/3)O3 and 0.99BaTi03-0.01Ba(M1/3Nb2/3)O3 series (M = Ca, Mn, Fe, Co, Ni, Cu, Zn), were examined. The Curie point was high when M was copper, while it was low when M was nickel. This was caused by the Jahn-Teller effect in the CuO6 octahedron keeping the Curie point high. For the 0.99BaTiO3-0.01 Ba(M1/3Nb2/3)O3 systems, the Curie points were correlated with axial ratioc/a.
TL;DR: In this paper, the authors devised a means of measuring the vorticity distribution using the reciprocal ultrasonic method using four corners of a square in the vortex field and theoretical and experimental analysis of calculating vortivity distribution in a vortex with angular velocity gradient in the radial direction is described.
Abstract: The authors devised a means of measuring the vorticity distribution using the reciprocal ultrasonic method. Vorticity measuring apparatus is arranged on four corners of a square in the vortex field and theoretical and experimental analysis of calculating vorticity distribution in the vortex with angular velocity gradient in the radial direction is described.
TL;DR: In this article, the chemical states of 119Sb5+ ions hydrolytically adsorbed on spinel type ferrimagnetic oxide CoFe2O4 powders are studied by means of emission Mossbauer spectroscopy of the daughter nuclide 119Sn.
Abstract: The chemical states of119Sb5+ ions hydrolytically adsorbed on spinel type ferrimagnetic oxide CoFe2O4 powders are studied by means of emission Mossbauer spectroscopy of the daughter nuclide119Sn. The spectra show a broadening which is attributed to the supertransferred hyperfine magnetic field coming from the magnetically ordered metal ions of the substrate. Distribution of the field is obtained from the spectra and its change with temperature is discussed.
TL;DR: 本研究は, VDT作業の時間の長さがヒトの情報処理能力に与える影響を調べることを目的とするキーを押すという単純作Chinese��を行った.
Abstract: 本研究は, VDT作業の作業時間の長さがヒトの情報処理能力に与える影響を調べることを目的とした. 作業時間は5, 10, 15, 30分間の4種類で, 作業内容はCRT画面上に○, △, □, ×の記号をランダムに表示させ, それに対応するキーを押すという単純作業を行った. 情報処理能力の変化の測定は, 作業前後に1桁の乱数を書かせ, その乱数列の質の変化により, その影響を検討した. その結果, 15分間作業まではフリッカー値の変化率が上昇し, 30分間作業では5分間作業と同じ変化率まで低下した. また, 乱数列の処理結果においても同様な変化傾向になった. このことより, 注視度の高いVDT作業においては視機能だけではなく, 思考機能や情報処理機能にも影響を与えることが明らかになった.
TL;DR: In this paper, the formation of intermolecular excimers in polyethersulfone (PES) dichloromethane solutions were observed at a PES concentration about 27 × 10−2 mol/l by fluorescence analysis.
Abstract: Formation of intermolecular excimers in polyethersulfone (PES) dichloromethane solutions were observed at a PES concentration about 27 × 10−2 mol/l by the fluorescence analysis External light energy irradiation enabled the formation of intramolecular excimers in the PES dichloromethane solution These chains can gain an access to each other in parallel though the molecular chains are considerably rigid The electron micrograph of the PES film, heat treated at 200°C for 72 hours, presented a diffraction micrograph, which suggests that the PES molecular aggregation is changed from a randomly coiled amorphous phase to an ordered one
Die Bildung zwischenmolekularer Excimer-Gruppen wurde bei Polyethersulfon (PES) in Dichlormethan-Losungen bei Konzentrationen um 2,7 × 10−2 mol/l durch Fluoreszenzanalyse nachgewiesen Die Bestrahlung mit Licht ermoglichte auch die Bildung intramolekularer Excimer-Gruppen; dabei legen sich Molekulsegmente parallel, obwohl die Molekule recht starr sind Aus Aufnahmen mit dem Elektronenmikroskop wurde gefolgert, das Polyethersulfon bei langerem Erhitzen auf 200°C von einem amorphen in einen geordneten Zustand ubergeht
TL;DR: In this paper, the protection of the O 6 -amide and N 2 -amino groups of guanosine with the (butylthio)carbonyl group is described.
Abstract: The protection of the O 6 -amide and N 2 -amino groups of guanosine with the (butylthio)carbonyl group is described. This group could be rapidly introduced in good yields and removed very easily under the conventional deprotective condition for the exo -amino acyl groups of other nucleoside bases.
TL;DR: In this article, the protection of the O6amide group of guanosine and the N3imide group of uridine with the carbonyl group was described, and the latter was introduced in good yields and is cleaved under mild conditions.
Abstract: We describe the protection of the O6-amide group of guanosine and the N3-imide group of uridine with the (butylthio) carbonyl group. This group is introduced in good yields and is cleaved under mild conditions.
TL;DR: In this paper, the distribution of Vickers dans deux bicristaux lamines a temperature ambiante, 423 K and 573 K dans des directions differentes.
Abstract: Analyse de la distribution de la durete Vickers dans deux bicristaux lamines a temperature ambiante, 423 K et 573 K dans des directions differentes
TL;DR: In this article, a model-based control concept is discussed for a relatively general system described by operators, and a sensitivity model is also examined as well as a parameter estimation scheme via sensitivity operators.
01 Jan 1988
TL;DR: In this paper, the authors investigated the effect of dimensionless shear stress, Reynolds number, Keulegan number and Galileo number on the rolling-up rate of river mud.
Abstract: Usually, the quantity of rolling-up of river mud is estimated as a function of shear stress in the same way as in the case of bed load transportation, In this way of estimation, however, such characteristics of rolling-up phenomenon as the small size of particles constituting bed material and the viscosity of mud are not properly considered. In this paper, a essential parameter for the modelling the rolling-up phenomenon has been investigated. As a result of calculation and analysis of many data, it has been found that the rolling-up phenomenon is effected by not only the dimensionless shear stress but also Reynolds number, Keulegan number and Galileo number. It has been noticed that also the Galileo number is the most important parameter to combine the other three parameters and to induce a new synthesized function of dimensionless shear stress, Galileo number and the ratio between specific gravity of particles and density of mud. This function is a synthetic parameter for the explanation of the rolling-up phenomenon including bed load transportation and density current. The rolling-up rate is in proportional to the 4.25th power of this new parameter. Good agreement has been confirmed between the analytical results and the data obtained by various investigators.