高灵敏压力传感器过载保护结构设计

采用微机电系统(MEMS)牺牲层技术制作的压力传感器具有芯片尺寸小,灵敏度高的优势,但同时也带来了提高过载能力的难题.为此,利用有限元法,对牺牲层结构压阻式压力传感器弹性膜片的应力分布进行了静态线性分析和非线性接触分析.通过这两种分析方法的结合,准确的模拟出过载状态下传感器的应力分布.在此基础上给出了压力传感器的一种结...     

高强度钢腐蚀疲劳裂纹扩展的温度效应和过载迟滞效应

通过在18,35和55℃蒸馏水中疲劳裂纹扩展试验,证明了超高强度钢30CrMnSiNi2A腐蚀疲劳具有强烈的温度效应,得到了ΔK值和温度对裂纹扩展速率影响的复合表达式。由于扩展速率数据拟合得到的表观激活能值(36.7kJ/mol)十分接近于氢在γ-Fe中的扩散激活能值,支持了氢助裂纹扩展的观点。对大气中疲劳裂纹扩展具有重要价值的过载迟滞效应,在腐蚀疲劳时显著地减小,在0.1Hz的低频率下尤其明显。     

Antiviral Activity of a Novel Compound CW-33 against Japanese Encephalitis Virus through Inhibiting Intracellular Calcium Overload

Japanese encephalitis virus (JEV), a mosquito-borne flavivirus, has five genotypes (I, II, III, IV, and V). JEV genotype I circulates widely in some Asian countries. However, current JEV vaccines based on genotype III strains show low neutralizing capacities against genotype I variants. In addition, JE has no specific treatment, except a few supportive treatments. Compound CW-33, an intermediate synthesized derivative of furoquinolines, was investigated for its antiviral activities against JEV in this study. CW-33 exhibited the less cytotoxicity to Syrian baby hamster kidney (BHK-21) and human medulloblastoma (TE761) cells. CW-33 dose-dependently reduced the cytopathic effect and apoptosis of JEV-infected cells. Supernatant virus yield assay pinpointed CW-33 as having potential anti-JEV activity with IC₅₀ values ranging from 12.7 to 38.5 μM. Time-of-addition assay with CW-33 indicated that simultaneous and post-treatment had no plaque reduction activity, but continuous and simultaneous treatments proved to have highly effective antiviral activity, with IC₅₀ values of 32.7 and 48.5 μM, respectively. CW-33 significantly moderated JEV-triggered Ca²⁺ overload, which correlated with the recovery of mitochondria membrane potential as well as the activation of Akt/mTOR and Jak/STAT1 signals in treated infected cells. Phosphopeptide profiling by LC-MS/MS revealed that CW-33 upregulated proteins from the enzyme modulator category, such as protein phosphatase inhibitor 2 (I-2), Rho GTPase-activating protein 35, ARF GTPase-activating protein GIT2, and putative 3-phosphoinositide-dependent protein kinase 2. These enzyme modulators identified were associated with the activation of Akt/mTOR and Jak/STAT1 signals. Meanwhile, I-2 treatment substantially inhibited the apoptosis of JEV-infected cells. The results demonstrated that CW-33 exhibited a significant potential in the development of anti-JEV agents.     

浅议低压配电系统的保护与特性配合

介绍在低压配电系统中要正确地选用低压电器，必须在各低压电器间保持良好的特性配合，才能正确地发挥和保护好各低压电器的功能。     

黑河地区俄网按功率减载的区域稳定控制

黑龙江省黑河地区通过110 kV布黑线从俄罗斯阿穆尔州购进电力,根据季节不同,俄罗斯电网向中方输送电力有功率限额.阐述了安全稳定控制装置、远方信号传输装置的功能,及黑河地区俄网按功率减载的安全稳定控制实施方案和运行效果.     

炮膛内高过载环境力测量系统设计

了获取弹丸在膛内高过载情况下的加速度信号,设计了一种弹载数据采集系统。选用高性能的Zynq 7000系列SoC芯片作为控制核心,将采集到的加速度信号通过A/D转换芯片送入大容量Nand Flash存储器完成数据的采集。通过对成品电路板的全面灌封技术,提高了系统整体的抗冲击能力。通过对实测结果进行分析,表明此系统可以准确地获取弹丸的膛内加速度变化曲线。     

华光潭梯级水电站远方过载切机装置的应用

分析了远方过载切机装置安装的必要性和动作原理。当电网线路过载时,有条件地切除华光潭梯级水电站的部份机组负荷,避免了可能出现的全部厂用电失去和输水长隧洞水锤冲击的安全隐患。     

发电机对称过负荷保护中额定电流不能按实际整定的危害及改进措施

分析了在WFBZ-01微机型发变组保护中,发电机对称过负荷及不对称过负荷保护的额定电流与实际不符带来的危害,并提出了改进措施。     

保护单台电力电容器的真空式全范围限流熔断器的开发

介绍了我国自行开发研制的保护单台电力电容器真空式全范围限流熔断器的基本结构和相应的研究性试验,给出了特殊设计的要求,以及较详细介绍了额定电压为6kV、额定电流为50A、开断电流为40kA的保护电力电容器用熔断器的设计范例。     

过载保护继电器的智能化设计

在研究了过载保护继电器保护原理的基础上,以PIC16F877单片机为核心部件,从硬件、软件两方面对过载保护继电器进行了智能化设计。同时,考虑到过载保护继电器的工作环境,采用隔离、神经网络滤波等措施进行了抗干扰设计,从而能够可靠实现电动机故障的自动诊断、智能控制、保护及远程串行通信等功能。