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51.
对硅灰对混凝土修补料性能的影响进行了研究,并与未掺硅灰修补料的稠度、强度、抹面性能等方面做了对比和分析。认为掺加一定量的硅灰可以提高混凝土修补料的和易性和可施工性,能使抹面效果更美观。 相似文献
52.
基于大型铁磁材料的磁致伸缩特性是电力设备发生电磁振动的主要因素,提出了一种适用于普通实验室环境的硅钢片磁致伸缩测量系统,设计了能产生外加磁场的螺线管用来激励硅钢片发生形变,运用陶瓷发热片和温度传感器对硅钢片温度进行调节和控制。基于高精度应变电阻片实现对硅钢片形变的测定,通过理论仿真和实验研究,该装置能准确测量饱和状态和不同温度下的磁致伸缩率。为电磁测量实验及电磁振动分析提供了可靠依据。 相似文献
53.
在进行高温硅功率器件设计时,为保证器件的温度特性,必须正确、恰当地选取硅单晶电阻率,理论分析与实验相结合,可根据硅功率器件额定结温确定硅单晶电阻率的上限值,根据硅功率器件反向击穿电压确定硅单晶电阻率的下限值,在此基础上,设计制造了满足坦克用的高温硅功率器件,额定结温达190℃。 相似文献
54.
笔者在前人针对硅钢片振动理论研究的基础上,优化了硅钢片由磁致伸缩而产生振动的数学模型。通过计算结果与试验结果的比较,分析影响硅钢片磁致伸缩的主要因素,并提出抑制措施。 相似文献
55.
We previously reported the direct electrochemical detection of insulin at bare carbon electrodes. Here a novel modified acetylene carbon black paste electrode(SiC/CB-CPE), based on the outstanding characteristics of silicon carbide nanostructure,was developed for the electrooxidation of insulin in alkaline solution and it was characterized by cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS) in 5 mmol/L Fe(CN)63-/4- solution. It is found that silicon carbide nanostructure doped into the CB-CPE greatly facilitates the redox electrochemistry of Fe(CN)63-/4- probe and the electrochemical oxidation of insulin. The electrooxidation of insulin is a one-electron and one-proton reaction and an irreversible adsorption-controlled electrode process. The anodic oxidation current increases linearly with the concentration of insulin from 1×10-7mol/L to1.2×10-6mol/L in 0.1 mol/L Na2CO3-NaHCO3 buffer solution(pH 10.0) and the detection limit was 50 nmol/L. In addition, the SiC/CB-CPE shows good sensitivity, reproducibility, renewability and capacity of resisting disturbance. 相似文献
56.
由电炉的结构和电气原理出发,分析了HR-3C灰熔点测定仪电加热系统中的故障及产生原因,对仪器进行了技术改造,改造后仪器运行良好。 相似文献
57.
Measurement of the thermal transport properties of dielectric thin films using the micro-Raman method 总被引:1,自引:0,他引:1
The micro-Raman method is a non-contact and non-destructive method for thermal conductivity measurement. To reduce the measurement error induced by the poor fit of the basic equation of the original micro-Raman method, we developed a new basic equation for the heat source ofa Gaussian laser beam. Based on the new basic equation, an analytical heat transfer model has been built to extend the original micro-Raman method to thin films with submicrometer- or nanometer-scale thickness. Experiments were performed to measure the thermal conductivity of dielectric thin films with submicrometer- or nanometer-scale thickness. The thermal resistance of the interface between dielectric thin films and their silicon substrate was also obtained. The obtained thermal conductivity of silicon dioxide film is 1.23 W/(m.K), and the interface thermal resistance between silicon dioxide film and substrate is 2.35×10^-8 m^2.K/W. The thermal conductivity and interface thermal resistance of silicon nitride film are 1.07 W/(m.K) and 3.69×10^-8 m^2.K/W, respectively. The experimental results are consistent with reported data. 相似文献
58.
A diode-triggered silicon controlled rectifier (DTSCR) is being developed as an electrostatic discharge (ESD) protection device for low voltage applications. However, DTSCR leaks high current during normal operation due to the Darlington effect of the triggering-assist diode string. In this study, two types of diode string triggered SCRs are designed for low leakage consideration; the modified diode string and composite polysilicon diode string triggered SCRs (MDTSCR & PDTSCR). Compared with the conventional DTSCR (CDTSCR), the MDTSCR has a much lower substrate leakage current with a relatively large silicon cost, and the PDTSCR has a much lower substrate leakage current with similar area and shows good leakage performance at a high temperature. Other DTSCR ESD properties are also investigated, especially regarding their layout, triggering voltage and failure current. 相似文献
59.
王志勇 《安阳师范学院学报》2009,(5):95-97
以正硅酸乙酯(TEOS)和三乙醇胺为原料、氢氧化钾为催化剂、丙酮作溶剂,通过酯交换反应合成了1-乙氧基杂氮硅三环化合物,并初步探讨了反应条件的影响,并用IR对所合成的产物的结构进行了表征。 相似文献
60.
采用磁致伸缩测试仪测量无取向硅钢片50WW800的磁致伸缩系数,并对不同钢种及不同退火工艺的无取向硅钢片的磁致伸缩系数进行比较,发现磁致伸缩系数存在最大值,且与磁感的大小、退火时间的长短及试样方向等因素密切相关。 相似文献