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951.
Aram A. Sahakyan Sergei K. Nikoghosyan Hrant N. Yeritsyan 《Central European Journal of Physics》2008,6(4):797-801
The influence of irradiation by electrons with an energy of 8 MeV, at dose intervals between 1013 and 2×1018el/cm2, on the properties of impurity doped, high-temperature superconductor YBa2Cu3−x
M
x
O
y
(M = Fe, Ni; x=0; x=0:01) ceramics has been studied.
It has been established that, as the irradiation dose is increased, the onset temperature of the transition to the superconducting
state (T
c
on
), and the intergranular weak link coupling temperature between granules (T
m
J
), exhibit an oscillation around their initial values of approximately about 1–1.5 K. This oscillation indicates that the
process of radiation defect formation in HTSC occurs in multiple stages. It was also found that the critical current (J
c
)decreases with an increase of the irradiation dose, and exhibits a local minimum at a dose of 8×1016el/cm2coinciding with minima for T
c
on
and T
m
J
at this dose. It was found that the introduction of Fe atoms to the ceramic decreases T
m
J
, while introducing Ni atoms decreases both T
c
on
and T
m
J
; it is suggested that this is a result of Ni substitution of Cu both in Cu2 plane sites and Cu1 chain sites. The introduction
of Ni causes a large change in the intergranular critical current density, J
c
. A critical irradiation dose is obtained (2×1018)after which all HTSC parameters strongly decrease, i. e. the superconductivity of HTSC is destroyed.
相似文献
952.
Shuhong Gao 《Proceedings of the American Mathematical Society》1999,127(6):1615-1623
A method is given for constructing elements in whose orders are larger than any polynomial in when becomes large. As a by-product a theorem on multiplicative independence of compositions of polynomials is proved.
953.
基于LAGRANGE插值的高阶微分中值定理 总被引:2,自引:0,他引:2
陈之兵 《应用数学与计算数学学报》2002,16(1):35-39
本文基于LAGRANGE插值,将微积分中非常重要的中值定理推广到了高阶的情形。 相似文献
954.
955.
D. Bourret M. Alyari J. Regnier R. Sempere J. Zarzycki 《International Journal of Infrared and Millimeter Waves》1984,5(11):1483-1491
A Q band interferometer for determining the complex permittivity of solids and liquids between 20°C and 1300°C has been developed. The Roberts and Von Hippel standing-wave method was used. The technique involves the utilization of a computer-assisted digital voltmeter for data acquisition and treatment. Results for a 67SiO2–33Na2O within the temperature range 20–400°C and in the liqid state (950°C) are presented. 相似文献
956.
用修正的RELIEF方法测量高速空气流瞬时速度的理论研究 总被引:3,自引:1,他引:2
修正了拉曼激发激光感应电子荧光(RamanExciationpulseLaser-inducedElectronicFluorescence简称RELIEF)方法,以实现对亚音速和超音速空气流多点时速度的测量,测量精度优于2%。 相似文献
957.
The results of high pressure experiments with ternary iodides of the general formula ABI6 with A = Ca, Dy, Ge, Sn, Pb and B = Th, U are described. These compounds transform from a β- to a γ-SnThI6-type structure, both variants of known trihalide structures (BiI3- and PuBr3-type). Trends and pecularities in the values for the minimal transformation pressures and in the velocities of transition are pointed out, and they are discussed in terms of geometric and electronic factors. 相似文献
958.
959.
The effect of pressure on the conductivity of fast ion conducting AgI-Ag2O-MoO3 glasses has been investigated down to 150 K. The observed variation of conductivities appears to support the application
of cluster model to the ionic glasses.
Contribution No. 258 from the Solid State and Structural Chemistry Unit. 相似文献
960.
M. I. Finston 《Optics & Laser Technology》1985,17(2):83-88
The elementary optics of rotating-mirror high-speed cameras are analysed geometrically. The images in an off-axis scanning mirror are shown to lie on Pascal's limacon. The Miller principle by which shuttering is accomplished is described. A simple estimate of motion blurring is compared with the Rayleigh criterion. 相似文献