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61.
Teruya Tanaka Junichi. H. Kaneko Yoshimi Kasugai Masaki Katagiri Hiroshi Takeuchi Takeo Nishitani Toshiyuki Iida 《Diamond and Related Materials》2005,14(11-12):2031
Radiation tolerance of a type IIa synthetic diamond detector was examined from irradiation of mono-energetic 14 MeV neutrons. Measurements of I–V (current–voltage) characteristics and energy spectrum for 5.486 MeV alpha particles were performed after neutron irradiation. In the I–V characteristics measurement, enhancement of rectification was observed after neutron irradiation of up to 2.0 × 1012 n/cm2. Concurrently with the enhancement of rectification, significant decrease in signal amplitude was observed in energy spectrum measurement for alpha particles. It is considered that these changes were due to increase in the concentration of defects acting as shallow energy levels in the forbidden band. For neutron irradiation of higher than 1.6 × 1013 n/cm2, weakening of the rectification characteristics and recovery of the signal amplitude were observed. These changes imply that deep energy levels, which were also considered to be introduced by defects, were dominant and weakened the effects of the shallow energy levels. Increase in the concentration of the deep trapping levels resulted in gradual decrease of the signal amplitude and degradation in the energy resolution. The peak for the alpha particles was obtained up to 5.5 × 1013 n/cm2. 相似文献
62.
Tungsten carbide nanopowders were synthesized successfully by electric discharge machining followed by annealing under a nitrogen atmosphere. The tungsten workpieces were initially melted and evaporated on the working surface during the electric discharge machining process, and then the tungsten powders were reacted with the carbon electrode and the working medium of kerosene to form the nanocrystalline WC1−x powders. The powders produced were characterized by XRD, SEM, and TEM. When annealing the powders under an N2 atmosphere, the cubic phases of WC1−x gradually changed to hexagonal W2C and then were transformed fully to nanocrystalline hexagonal WC at 1200 °C, with the nanocrystalline tungsten carbide encapsulated in a carbon shell. On the other hand, under an H2 atmosphere, the WC1−x phase changed via a W2C phase to reduced powders of pure tungsten at 1000 °C or were reduced directly from WC1−x to elemental W. 相似文献
63.
两种具有电双稳态的全有机络合物 总被引:9,自引:0,他引:9
首次发现两种在室温下即具有电双稳态的全有机(有机-有机)络合物,分别称为MCA+TCNQ和BBDN+TCNQ。它们可在真空中制备成薄膜,在数伏电压的作用下,从高电阻至低电阻的跃迁时间小于100ns,因此可作为一次写入的存储器材料。根据我国目前最小刻线宽度的水平,可望在1.6cm2的SiO2平面上做出64Mb的存储器。 相似文献
64.
介绍了12kV中置柜联锁装置的设计原则,分析了现有中置柜联锁装置在实际运行中存在的问题和不足,提出了改进和完善中置柜联锁装置的设计方法。实际应用表明,改进后的中置柜联锁装置的功能更加完善,安全性更加可靠,完全达到了五防闭锁要求。 相似文献
65.
将单片机控制技术融入到家电设计,实现家电智能化,提高其性价比。本文基于盛群单片机HT45R35的应用开发,设计一款吸油烟机控制器,通过硬件及软件优化设计,降低单片机应用成本,提高其工作稳定性。 相似文献
66.
Z. Bukowski K. Gofryk T. Plackowski D. Kaczorowski 《Journal of Alloys and Compounds》2005,400(1-2):33-36
Single crystals of UNi0.5Sb2 were investigated by means of Seebeck coefficient and Hall effect measurements in the temperature range 5–300 K. The results corroborated the occurrence of two magnetic phase transitions: from para- to antiferromagnetic state at TN = 161.5 K and a spin-reorientation near Tt = 64 K. The first-order character of the latter feature was proved by studying in detail the electrical resistivity and the magnetic susceptibility of single-crystalline UNi0.5Sb2 in the vicinity of Tt. 相似文献
67.
Yuning Lou Yajuan Dong Xiaoyong Wang Feirong Gong Min Zhao Zongming Rong 《Journal of surfactants and detergents》2021,24(1):3-13
Two generations of novel linear-dendritic carboxylate surfactants C18-G1-(COONa)2 and C18-G2-(COONa)4 have been synthesized by the divergent method and their structures are characterized by 1H Nuclear Magnetic Resonance and Infrared analysis. The electrical conductivity measurement is used to measure the Krafft temperatures of C18-G1-(COONa)2 and C18-G2-(COONa)4, which are much smaller than those of the corresponding conventional surfactant sodium stearate. The markedly enhanced solubility of two linear-dendritic surfactants is ascribed to the high hydrophilicity of surfactant headgroups induced by the carboxylate and ester groups. The critical micelle concentration (CMC) values obtained from both the electrical conductivity and surface tension measurements indicate that the micellizations of linear-dendritic surfactants become favorable with the increase in the number of the surfactant headgroup. However, the surface activity parameters including the surface tension at the CMC, maximum surface excess, and minimum surface area reveal that C18-G1-(COONa)2 exhibits greater efficiency in absorbing at the air/water interface compared to C18-G2-(COONa)4, owing to their different steric repulsions of the surfactant headgroups. In addition, C18-G1-(COONa)2 and C18-G2-(COONa)4 have higher emulsifying ability than the conventional surfactants sodium stearate and sodium octadecyl sulfate. 相似文献
68.
稀土元素对钯室温电学性能的影响 总被引:2,自引:2,他引:2
研究了稀浓度(0.6at%以下)稀土元素(La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Dy、Er、Yb)对钯的室温电学性能的影响。所有稀土元素均提高钯的电阻率(p)、降低电阻温度系数(α),实验结果与理论分析证明(p·α)_((?)d-RE)d=(p·α)_(Pd)。Gd以前的稀土元素降低钯的对铜热电势(ε),其余重稀土元素增大钯的对铜热电势。按0.1at%RE归一化处理的实验数据表明,轻稀土元素对钯电阻率的影响稍大于重稀土,但Ce、Eu、Yb呈反常影响,化合价和尺寸因素是影响电学性能的主要因素。 相似文献
69.
通过熔融共混方法制备导电高分子复合材料丙烯腈-苯乙烯-丙烯酸酯共聚物(ASA)/天然石墨(NGR)/炭黑(CB),采用电磁屏蔽测量仪、四探针电阻率测量仪和动态热机械分析仪对复合材料的电性能和力学性能进行详细研究。结果表明,ASA/NGR复合材料的体积电阻率随着炭黑含量增加而增加;同时在30 MHz~1500 MHz范围内,复合材料的电磁屏蔽性能从28 dB提高到38 dB,符合商业要求。炭黑的加入大大改善了材料力学性能,弯曲强度从31 MPa增加到41 MPa;动态储能模量从4.6 GPa增加到14.5 GPa。 相似文献
70.