応用物理
Online ISSN : 2188-2290
Print ISSN : 0369-8009
ISSN-L : 0369-8009
27 巻 , 2 号
選択された号の論文の9件中1~9を表示しています
  • 伊藤 義郎
    1958 年 27 巻 2 号 p. 65-72
    発行日: 1958/02/10
    公開日: 2009/02/20
    ジャーナル フリー
    Following the author's early paperj, some analyses are performed on the temperature distribution of cylindrical electrodes of a diode at high temperatures, where the dissipation energy of electrodes is transferred chiefly by radiation.
    The fundamental equations are deduced under the following assumptions.
    1. Heat radiation and reflection at electrode surfaces follow Lambert's law.
    2. Heat conduction through electrode walls is negligible.
    3. Total emissivity of the electrode surfaces is independent of temperature.
    4. The electrodes are of the same length.
    The equations are given by the following formulas. For the diode
    _??_
    where
    K1(Z), K2(Z): kernel functions of the co-existive Fredholm's integral equations of the second kind. Q(Z): heat energy dissipating from the surface of electrode at the ultimate state of mutual radiation heating.
    The method of numerical solution of these equations are given, and their results are discussed briefly.
  • 和地 洋平
    1958 年 27 巻 2 号 p. 72-77
    発行日: 1958/02/10
    公開日: 2009/02/09
    ジャーナル フリー
    When some uniaxial single crystal such as K. D. P. or A. D. P. is used as a Kerr cell shutter or for other electro-optical purposes, the electric field must be supplied in the direction of the light path. Thus transparent electrode is required and the so-called “Nesa glass” offers one of ways answering this requirement. But because of its high resistivity, it was reported that the “Nesa glass” could not response to high frequency signals. Another pos-sibility of obtaining transparent electrode is the use of gold film evaporated by a suitable method. In this study, structure, electrical resistivity, light transmission, and capacity of full-coated and grid-coated gold films are measured for the purpose of examining that pos-sibility. Following results are obtained: (a) Full-coated film, 100A in thickness, had 20 ohm resistivity and 35% transmission so this is but a very inefficient electrode (b) One of grid-coated films had a few ohm resistivity, 50% transmission and 84% capacity. Hence, (c) if circumstances permit a little higher resistivity, it is possible that both transmission and capacity are increased by choosing a suitable grid form, and it is believed that high trans-parent and low resistance electrode is obtained by grid-coated gold films.
  • 水野 博之, 増田 淳三
    1958 年 27 巻 2 号 p. 78-82
    発行日: 1958/02/10
    公開日: 2009/02/20
    ジャーナル フリー
    Diffusion coefficients of activators that are usually used in nickel sleeve of oxide cathode, and activation energies of diffusion are obtained. The diffusion coefficients are deduced by evaluations based on the decreasing characteristics of the activators in thin nickel filaments (50 microns in thickness) heated at a constant temperature between 1173°K and 1573°K for hundred hours. The activation energy is also deduced for each activator from the slope of curve log D_??_1/T.
    The experiments are carried out on Mg, Mn, Si, Al, W, and the activation energies are given respectively as 1.5, 2.1, 2.7, 2.9 and 3.8(eV), and the diffusion coefficients are given at two representative temperatures:
    _??_
    From these results, the order of diffusion ability of activators is considered as Mg→Mn→Si_??_Al→W. Accordingly, it is desirable that the most appropriate activator be selected for each electronic tube to serve its purpose.
  • 林 主税
    1958 年 27 巻 2 号 p. 83-88
    発行日: 1958/02/10
    公開日: 2009/02/09
    ジャーナル フリー
    Effect of adsorption in producing and measuring vacuum usually becomes predominant at the vacuum higher than 10-3mmHg, and its significance is revealed by the recent developments in ultra high vacuum techniques. This paper is divided into Part 1 and Part 2.
    In Part 1, it is shown that approximate treatments of gas flow in high vacuum as of a kind of diffusion problem give some equations, which are useful to clarify the effect of adsorption in non-stationary gas flow problems. Diffusion constant is expressed including terms of the sticking probability, the time of adsorption and the roughness factor as well as the usual geometrical factor. As a rule, the rate of migration of a molecule is determined by two terms. One of which is the average time spent by a molecule to terminate a flight from a point on the wall to the next point on it, and the other the time spent on the wall, the duration of which should be correlated with the characteristics of adsorption. Calculations give that the average time spent during the stay on the wall is longer in some cases than the time of flight.
    As to geometrical factors, the effect of adsoption depends, of course, to surface to volume ratio as evidenced by the flow of gas through a narrow pipe or a fine pin-hole.
  • 山本 美喜雄
    1958 年 27 巻 2 号 p. 88-98
    発行日: 1958/02/10
    公開日: 2009/02/09
    ジャーナル フリー
    As regards the classical problem of the Wiedemann effect in ferromagnetic polycrystalline substances, no satisfactory theory has yet been proposed except Fromy's theory for the case of thin-walled tube specimens. In a simple way, a general expression is derived for the Wiedemann effect or for the torsion angle per unit length, θr of a cylindrical layer of the radius r in the case of a cylindrical rod of ferromagnetic substance, fixed at its one end and magnetized by a longitudinal magnetic field, Hl, parallel to, and by a circular magnetic field, Hcr, around, the rod axis. When the elastic energy is negligible as compared with the magnetic field energy as in normal ferromagnetics, the general expression is reduced to
    θr=(2/r){λl(Hr) -λt(Hr)}(HtHcr/Hr2),
    where Hr=(Hl2-Hcr2)1/2 and λl(Hr) and λt(Hr) are, respectively, the longitudinal and transverse magnetostrictions accompanied with Hr. This expression is rewritten, for the surface of a rod of the radius a, as
    θa=(2/a){λl(Ha)-λt (Ha)}(HlHca/Ha2),
    which holds also for a thin-walled tube and is the expression derived already by Fromy. This expression is further reduced to
    θa=(3/a)•λl(Ha)•(HlHca/Ha2),
    if the volume magnetostriction is considered negligible as in normal ferromagnetics. It is shown that the above expressions can explain, completely qualitatively and to a considerable extent quantitatively, all of the available experimental facts concerning the Wiedemann effect.
  • 山本 京治, 山田 良輝, 和田 八三久
    1958 年 27 巻 2 号 p. 98-103
    発行日: 1958/02/10
    公開日: 2009/02/09
    ジャーナル フリー
    A new simple method has been developed for the determination of visco-elastic property of a liquid at ultrasonic frequencies. A composite resonator is made by comenting a brass reed to the lower end of a longitudinal quartz resonator. The dynamic viscosity and rigidity of a liquid are calculated from the decrease of both the resonant frequency and mechanidal Q-value of the composite resonator when the lower half of the brass reed is immersed in the liquid. This method is less sensitive compared with the torsional crystal method, but is very simple in construction and can successfully be applied to high loss materials.
    Some liquids and gels have been investigated in a preliminary evaluation of the behaviors of the apparatus. The gel of aqueous solutions of gelatin shows appreciable rigidity at 100 kc/s, the modulus of rigidity being proportional to the square of concentration. The dynamic rigidity of silicone oil at 100 kc/s increases with increasing molecular weight, but above a critical molecular weight the increase is very slow and becomes asymptotic to a value of 16.5×105dyn/cm2 at 20°C. This asymptotic value decreases with increasing temperature. The viscosity of molten cetyl alcohol shows an abrupt increase at solidification point and it is suggested that this apparatus can be used for precise determination of solidification point of such a waxy material.
  • 岡田 紀夫, 廉 成根
    1958 年 27 巻 2 号 p. 104-110
    発行日: 1958/02/10
    公開日: 2009/02/09
    ジャーナル フリー
    Electrical volume resistivity and dynamic mechanical properties of fractionated PVA films, which absorbed water in various relative humidities at 20°C, have been measured. It is shown that there is a transition range in physical properties of humidified PVA films at round 10% water content. This suggests the nature of absorbed water in PVA films.
    It is found that the dynamic mechanical properties of PVA films are not affected by after heat-treatment, that is, not related to the degree of crystallinity but depend on absorbed water content.
    The water content dependence of dynamic mechanical properties is similar to the temperature dependence, the former being more remarkable in comparison with the latter.
  • 若島 久男
    1958 年 27 巻 2 号 p. 110-115
    発行日: 1958/02/10
    公開日: 2009/02/09
    ジャーナル フリー
    The profile of rouse rotors of mechanical boosters and leakage through clearances between sliding members are studied. The maximum volume of gas evacuated per revolution of the coupled rotors is found independent of the tooth profile and becomes approximately 4×(rotor diameter) 2 × rotor thickness. As for the leakage, two identical cylinders are assumed to lie parallel with a small known clearance between them through which gas flows by pressure difference. Approximate calculation of the leakage assures that if the clearance between rotors and casing is less than, 0.6 mm, the booster is fit for producing high vacuum.
  • 高元 曄夫
    1958 年 27 巻 2 号 p. 116-117
    発行日: 1958/02/10
    公開日: 2009/02/09
    ジャーナル フリー
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