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1.
The experimental researches on the chemical deposition of Ni-Mo-P amorphous alloys were carried out by adding Na2 MoO4 into acidic solutions. The optimum technology conditions were obtained by orthogonal design experiments. The structures and the relationship between compositions and their thermal stability were studied by energy spectrum (EC), scanning electron micrograph and X-ray diffraction spectrum. Compared with Ni-P amorphous alloys, the Ni-Mo-P amorphous alloys have high crystallization temperature and thermal stability, and the hardness reaches its peak when the annealing temperature is 500 ℃. With the increase of the heat treatment temperature, the surface morphology of the alloys changes. 相似文献
2.
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为了扩展电流卡钳的频率测试范围,根据其等效电路模型,分析并测试了传输阻抗特性,发现了传输阻抗在频率范围内的非线性现象,进而提出了基于放大器的线性补偿方法.通过测试结果表明,在1-50kHz的被测信号情况下,匹配了放大器的电流探头的传输阻抗的波动范围≤±1dB.因而,利用这一补偿方法,可以给单片机信号采集转换成被测电流值带来方便. 相似文献
4.
Yinshun WANG Xiang ZHAO Junjie HAN Huidong LI Yin GUAN Qing BAO Xi XU Shaotao DAI Naihao SONG Fengyuan ZHANG Liangzhen LIN Liye XIAO 《Frontiers of Electrical and Electronic Engineering in China》2009,4(1):104-113
Abstract A 630-kVA 10.5 kV/0.4 kV three-phase high temperature superconducting (HTS) power transformer was successfully developed
and tested in a live grid. The windings were wound by hermetic stainless steel-reinforced multi-filamentary Bi2223/Ag tapes.
The structures of primary windings are solenoid with insulation and cooling path among layers, and those of secondary windings
consist of double-pancakes connected in parallel. Toroidal cryostat is made from electrical insulating glass fiber reinforced
plastics (GFRP) materials with room temperature bore for commercial amorphous alloy core with five limbs. Windings are laid
in the toroidal cryostat so that the amorphous core operates at room temperature. An insulation technology of double-half
wrapping up the Bi2223/Ag tape with Kapton film is used by a winding machine developed by the authors. Fundamental characteristics
of the transformer are obtained by standard short-circuit and no-load tests, and it is shown that the transformer meets operating
requirements in a live grid.
__________
Translated from Proceedings of the CSEE, 2007, 27(27): 24–31 [译自:中国电机工程学报] 相似文献
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W. Hu Florence Y. M. Chan D. P. Webb Y. C. Chan Y. W. Lam 《Journal of Electronic Materials》1996,25(12):1837-1840
The optical properties of hydrogenated amorphous silicon thin films prepared by a new thermocatalytic plasma enhanced chemical
vapor deposition (PECVD) method are here reported for the first time. The transmission spectrum of the film, deposited at
a rate of 1.5 nm/s, was measured between 500 and 1100 nm. The envelopes of the transmission spectrum interference maxima and
minima were analyzed to reveal the absorption coefficient α(λ@#@), the refractive indexn(λ), the average thickness of the film (791 nm) and the variation of the thickness (11.4 nm), using an analysis which takes into
account film inhomogeneity. The modified Newton's method of numerical analysis was used to obtain the optical parameters.
The optical band gap ε0} was determined to be 1.69 eV from the absorption coefficient spectrum, commensurate with values quoted for lower deposition
rate PECVD films. The value for ε0}, the small variation of the film thickness, and a value for the defect density of 3.7 x 1015}cm-3} determined for similar material in other work indicate that the thermocatalytic PECVD method can produce acceptable quality
films at a high deposition rate. 相似文献
7.
Thin films of amorphous tungsten oxide were deposited by sputtering onto glass substrates coated by conductive indium–tin oxide. The films were sputtered at different oxygen-to-argon flow ratios with different pressure and power. Elastic recoil detection analysis determined the density and the stoichiometry. X-ray diffraction measurements showed that the films were amorphous. The films were electrochemically intercalated with lithium ions. At several intercalation levels of each film, the optical reflectance and transmittance were measured in the wavelength range 0.3–2.5 μm. We study the effect of various sputtering conditions on the coloration efficiency of the films and on the luminous and solar optical properties. The O2/Ar ratio and the sputter pressure determine to a large extent the optical absorption. As-deposited sputtered tungsten oxide with sufficiently little oxygen exhibits an absorption peak similar to the case of lithium intercalation. 相似文献
8.
采用电弧熔炼母合金、普通铜模吸铸工艺 ,制备出尺寸规格为 2 0mm× 10mm× 1mm的板状Fe -Co -Zr -Mo -W -B系Fe -基大块非晶合金。经DTA检测 ,所制备的Fe -基非晶合金具有明显的玻璃转变温度和较宽的过冷液相区 (Tg=884K ,ΔTx≥ 6 0K)。采用压痕试验法测定了该板状Fe -基大块非晶合金的断裂韧性 ,其铸态断裂韧性在 1.6MPa·m1/ 2 量级。 相似文献
9.
Jun-Ichi Kodama Takefumi Tsuboi Nobuo Okamoto 《Journal of Electronic Materials》1999,28(12):1461-1465
We previously reported on an extremely small temperature coefficient of resistivity (TCR) of thin amorphous Ni-Si film resistors
fabricated by new flash evaporating method, which have a wide range of resistivity.1 In the present paper, we describe the structural and chemical properties of these films for the purpose of clarifying the
cause of resistive change of films resulting from heat treatment. X-ray diffraction patterns show that Ni-Si films with greater
than 20 wt.% Si remains predominantly amorphous after heat treatment. Changes in composition and binding energy of the films
resulting from heat treatment are measured by means of XPS. Electrical characteristics are also investigated as a function
of Si concentration and temperature. The resistance variations resulting from heat treatment are found to originate from a
structural change. The activation energy needed for this change is obtained by analyzing the extent of change during isothermal
heating and found to vary from 1 eV to 2.5 eV with increasing Si content from 20 wt.% to 80 wt.%. 相似文献
10.