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On Similarities and Differences of Invasive and Non-Invasive Electrical Brain Signals in Brain-Computer Interfacing
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作者 David Steyrl Reinmar J. Kobler Gernot R. Müller-Putz 《Journal of Biomedical Science and Engineering》 2016年第8期393-398,共7页
We perceive that some Brain-Computer Interface (BCI) researchers believe in totally different origins of invasive and non-invasive electrical BCI signals. Based on available literature we argue, however, that although... We perceive that some Brain-Computer Interface (BCI) researchers believe in totally different origins of invasive and non-invasive electrical BCI signals. Based on available literature we argue, however, that although invasive and non-invasive BCI signals are different, the underlying origin of electrical BCIs signals is the same. 展开更多
关键词 Brain-Computer Interfaces electrical Brain signals Invasive signals Non-Invasive signals COMPARISON
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Variational Mode Decomposition-Informed Empirical Wavelet Transform for Electric Vibrator Noise Analysis
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作者 Zhenyu Xu Zhangwei Chen 《Journal of Applied Mathematics and Physics》 2024年第6期2320-2332,共13页
Electric vibrators find wide applications in reliability testing, waveform generation, and vibration simulation, making their noise characteristics a topic of significant interest. While Variational Mode Decomposition... Electric vibrators find wide applications in reliability testing, waveform generation, and vibration simulation, making their noise characteristics a topic of significant interest. While Variational Mode Decomposition (VMD) and Empirical Wavelet Transform (EWT) offer valuable support for studying signal components, they also present certain limitations. This article integrates the strengths of both methods and proposes an enhanced approach that integrates VMD into the frequency band division principle of EWT. Initially, the method decomposes the signal using VMD, determining the mode count based on residuals, and subsequently employs EWT decomposition based on this information. This addresses mode aliasing issues in the original method while capitalizing on VMD’s adaptability. Feasibility was confirmed through simulation signals and ultimately applied to noise signals from vibrators. Experimental results demonstrate that the improved method not only resolves EWT frequency band division challenges but also effectively decomposes signal components compared to the VMD method. 展开更多
关键词 electric Vibrator Noise Analysis signal Decomposing Variational Mode Decomposition Empirical Wavelet Transform
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Analysis of Aluminum Alloy Double-Pulse MIG Welding Arc Signal Characteristics Based on Broadband Mode Decomposition
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作者 Yin Si Zixiong Xia +2 位作者 Wei Liu Kexin Zhang Xiangyu Song 《Journal of Electronic Research and Application》 2024年第4期7-16,共10页
Welding voltage and current in arc signals are directly related to arc stability and welding quality.Process experiments with different parameters were organized according to the orthogonal experimental design method ... Welding voltage and current in arc signals are directly related to arc stability and welding quality.Process experiments with different parameters were organized according to the orthogonal experimental design method by constructing an aluminum alloy double-pulse metal inert gas(MIG)welding arc electric signal test platform.The data acquisition system of the aluminum alloy MIG welding process was established to obtain real-time arc signal information reflecting the welding process.The aluminum alloy’s collected double-pulse arc current signals are decomposed adaptively by broadband mode decomposition(BMD).The direct current(DC)signal,pulse signal,distortion signal,ripple signal,and noise signal are separated and extracted,and the composite multiscale fuzzy entropy(CMFE)is calculated for the component set of the electrical signal.The experimental results show that the current waveform obtained by the double-pulse MIG welding current signal is consistent with the corresponding weld forming diagram.Simultaneously,the composite multiscale fuzzy entropy is calculated for the arc characteristic parameters.The rationality of matching process parameters and arc stability of aluminum alloy’s double-pulse MIG welding were evaluated. 展开更多
关键词 Double-pulse MIG welding electric arc signal Broadband mode decomposition Welding stability
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Effects of Home Laundering on Electrical Resistance of Signal Transmission Lines on Colored E-Textiles
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作者 Umut Kivanc Sahin Senem Kursun Bahadir 《Journal of Energy and Power Engineering》 2017年第5期336-344,共9页
The aim of this work was to investigate the electrical resistance change of electro-textiles manufactured using cotton fabrics with stainless steel and silver plated PA yarns incorporation after being subjected to hom... The aim of this work was to investigate the electrical resistance change of electro-textiles manufactured using cotton fabrics with stainless steel and silver plated PA yarns incorporation after being subjected to home laundering, i.e. detergent washing and silicone softening. Electrical resistances of conductive yams inside the fabric structure were compared and discussed statistically before and after washing and softener application. Greatest changes in electrical resistances were observed with samples including silver plated PA yams. After five washing cycles with detergent, silicone softening agent is removed from yarns by washing, and thus conductivity increases. Further washing of e-textiles with detergent for five more cycles causes decrease in conductivity, because of chemical effects of detergent and mechanical effects of washing process such as abrasion due to friction. Detergent which has negative reactive sites bonds with metal ions reduces conductivity. 展开更多
关键词 Conductivity electrical resistance signal transmission lines electro-textiles conductive yam home laundering DETERGENT silicone softening agent.
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Low-Power CMOS IC for Function Electrical Stimulation of Nerves 被引量:1
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作者 李文渊 王志功 张震宇 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2007年第3期393-397,共5页
A low-power IC for function electrical stimulation (FES) of nerves is designed for an implantable system and fabricated in CSMC's 0.6μm CMOS technology. The IC can be used for stimulating animals' spinal nerve bu... A low-power IC for function electrical stimulation (FES) of nerves is designed for an implantable system and fabricated in CSMC's 0.6μm CMOS technology. The IC can be used for stimulating animals' spinal nerve bundles and other nerves connected with a cuff type electrode. It consists of a pre-amplifier,a main amplifier,and an output stage. According to the neural signal spectrum,the bandwidth of the FES signal generator circuit is defined from 1Hz to 400kHz. The gain of the circuit is about 66dB with an output impedance of 900. The 1C can function under a single supply voltage of 3-5V. A rail-to-rail output stage helps to use the coupled power efficiently. The measured time domain performance shows that the bandwidth and the gain of the IC agree with the design. The power consumption is lower than 6mW. 展开更多
关键词 neural signal CMOS function electrical stimulation low power NERVE
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Electrical Characteristics of Plasma Plume During Pulse Wave Laser Welding
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作者 Tong Liu Lijun Yang +1 位作者 Shengbin Zhao Yiming Huang 《Transactions of Tianjin University》 EI CAS 2019年第4期420-428,共9页
To detect the real-time plasma plume during pulse wave Nd:YAG laser welding, experimental studies were conducted based on asynchronous signal acquisition system. The electrical signals of the laser-induced plasma plum... To detect the real-time plasma plume during pulse wave Nd:YAG laser welding, experimental studies were conducted based on asynchronous signal acquisition system. The electrical signals of the laser-induced plasma plume were obtained by a passive acquisition system. The plume was directly observed and recorded using synchronous high-speed camera. The results showed that the waveform of the signals was in accordance with the periodical laser power. The signals decreased after the laser was turned on and fl uctuated relatively steadily on the stable stage and then increased to 0 V after the laser beam was turned off . The decreasing time of the electrical signals was roughly 1.0 ms, and it decreased with the increasing peak power. However, the average power had insignifi cant eff ect on the signal decreasing time. 展开更多
关键词 PULSE wave Laser WELDING Plasma PLUME electrical signal PASSIVE PROBE
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A novel wavelet method for electric signals analysis in underwater arc welding
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作者 张为民 王国荣 +1 位作者 石永华 钟碧良 《China Welding》 EI CAS 2009年第2期12-16,共5页
Electric signals are acquired and analyzed in order to monitor the underwater arc welding process. Voltage break point and magnitude are extracted by detecting arc voltage singularity through the modulus maximum wavel... Electric signals are acquired and analyzed in order to monitor the underwater arc welding process. Voltage break point and magnitude are extracted by detecting arc voltage singularity through the modulus maximum wavelet (MMW) method. A novel threshold algorithm, which compromises the hard-threshold wavelet (HTW) and soft-threshold wavelet (STW) methods, is investigated to eliminate welding current noise. Finally, advantages over traditional wavelet methods are verified by both simulation and experimental results. 展开更多
关键词 underwater arc welding electric signals wavelet method threshold algorithm
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Seismic electric signals in seismic prone areas
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作者 Nicholas V.Sarlis Panayiotis A.Varotsos +6 位作者 Efthimios S.Skordas Seiya Uyeda Jacques Zlotnicki Toshiyasu Nagao Anatoly Rybin Mary S.Lazaridou-Varotsos Konstantina A.Papadopoulou 《Earthquake Science》 CSCD 2018年第1期44-51,共8页
The Varotsos-Alexopoulos-Nomicos (VAN) method of short-term earthquake prediction was introduced in the 1980s. The VAN method enables estimation of the epicenter, magnitude and occurrence time of an impending earthq... The Varotsos-Alexopoulos-Nomicos (VAN) method of short-term earthquake prediction was introduced in the 1980s. The VAN method enables estimation of the epicenter, magnitude and occurrence time of an impending earthquake by observing transient changes of the electric field of the Earth termed seismic electric signals (SES). Here, we present a few examples of SES observed in various earthquake prone areas worldwide. 展开更多
关键词 seismic electric signals VAN method earthquake prediction EMSEV-Bishkek RS-RAS cooperation
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Modeling and Implementation of AC Electrical Capacitance Tomography
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作者 K. Manikandan S. Sathiyamoorthy 《Circuits and Systems》 2016年第11期3818-3830,共14页
Electrical Capacitance Tomography (ECT) determines the dielectric permittivity of the interior object depending on the measurements of exterior capacitance. Generally, the electrodes are placed outside the PVC cylinde... Electrical Capacitance Tomography (ECT) determines the dielectric permittivity of the interior object depending on the measurements of exterior capacitance. Generally, the electrodes are placed outside the PVC cylinder where the medium to be imaged is present;but in ECT using inter-electrode capacitance measurements can be achieved by placing inside of the dielectric medium. In the proposed ECT system, the ECT sensor is modeled using ANSYS software and the model is implemented in real ECT system. For each step of measurement, a stable AC signal is applied to a pair of electrodes that form a capacitor. The novel system is to measure the capacitance range variation in picofarad and the corresponding voltage ranges from 1 volt to 4 volts. The switching speed of all combinational electrodes is implemented using embedded system to achieve higher speed performance of AC ECT system which eliminates the drift and stray capacitance error. This is yielding the original image of unknown multiphase medium inside the electrodes using Lab VIEW. This paper investigates several advantages such as improved overall system performance;simple structure, avoids stray capacitance effect, reduces the drift problem and achieves high signal to noise ratio. 展开更多
关键词 electrical Capacitance Tomography ANSYS Lab VIEW Embedded System AC signal
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Effect and mechanism of electroacupuncture at"Baihui"and"Shenshu"on improving cognitive impairment in APP/PS1 mice
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作者 CHEN Zi-qi SUN Zhi-qi +2 位作者 HUANG Bo-hao ZHAO Fan-ying LIU Zi-wang 《Journal of Hainan Medical University》 CAS 2023年第5期31-36,共6页
Objective:To observe the effect of electroacupuncture(EA)at"Baihui"(GV20)and"Shenshu"(BL23)on cognitive impairment in AD model mice,and to explore its mechanism.Methods:A total of 24 model mice wer... Objective:To observe the effect of electroacupuncture(EA)at"Baihui"(GV20)and"Shenshu"(BL23)on cognitive impairment in AD model mice,and to explore its mechanism.Methods:A total of 24 model mice were randomly divided into EA,medication and model groups,8 mice in each group.Another 8 C57BL/6J mice were used as the normal control.The rats in the EA group were treated with electrical stimulation at Baihui(GV20)and Shenshu(BL23),and those in the medication group were treated with donepezil hydrochloride,once a day for 21 days.Adopting the Maorris water maze method to detect the behavior of mice and using HE staining to observe the morphological structure of neurons in the hippocampal region of mice.Finally the expression of GSK-3βandβ-catenin protein contents in the hippocampus of mice in each group was detected by Western blot.Results:Compared to the model group,the evasion latency of the electroacupuncture group and the western medicine group were significantly shorter,and the dwell time in the target quadrant and the number of crossing the plateau were increased(P<0.05),and the hippocampal neurons in each treatment group were closely arranged and complete,with a clearer hierarchy.Western blot assay results showed that the expression ofβ-catenin protein was significantly increased and GSK-3βprotein expression was decreased in the hippocampal region of mice in the electroacupuncture and western medicine groups compared with the model group(P<0.05).Conclusion:Ea at"Baihui"(GV20)and"Shenshu"(BL23)can significantly improve the cognitive function of APP/PS1 mice,which may be connected with the activation of Wnt/β-catenin signaling pathway. 展开更多
关键词 Alzheimer's disease electric acupuncture Wnt/β-catenin signaling pathway Cognitive impairment
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基于电场耦合的电能信号并行传输系统串扰抑制方法 被引量:1
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作者 苏玉刚 邓晨琳 +3 位作者 胡宏晟 孙跃 李雨蒙 邓仁为 《电工技术学报》 EI CSCD 北大核心 2024年第6期1613-1626,共14页
针对较大功率电场耦合无线电能传输系统信号双向高速传输的需求,该文提出一种基于部分能量通道的电能与信号并行传输系统的串扰抑制方法。通过对所提出的系统拓扑进行分析,给出了电能传输增益表达式与电能串扰增益表达式,并分析了阻波... 针对较大功率电场耦合无线电能传输系统信号双向高速传输的需求,该文提出一种基于部分能量通道的电能与信号并行传输系统的串扰抑制方法。通过对所提出的系统拓扑进行分析,给出了电能传输增益表达式与电能串扰增益表达式,并分析了阻波电路参数变化对电能串扰增益的影响;基于交流阻抗法及香农定理分别给出了信号传输增益及信道容量表达式,分析了信号支路参数对信道容量的影响;在综合考虑信号传输增益、信道容量及阻波电路参数敏感性的情况下,给出系统信号支路参数的设计方法。该方法能保证系统在较大功率下降低电能串扰,保障信号稳定传输,实现信号的双向高速传输。通过仿真与实验验证了所提出的拓扑和参数设计方法的有效性。搭建的实验装置实现了传输530.4 W的电能,23.28 Mbit/s信号正向传输速度和24.2428 Mbit/s信号反向传输速度。 展开更多
关键词 电场耦合式无线电能传输 信号双向传输 电能串扰 参数设计
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基于正弦同源-概率空间协同互补的涌流闭锁方案
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作者 陈勇 张员宁 +3 位作者 黄景光 刘琦 李浙栋 林湘宁 《电力自动化设备》 EI CSCD 北大核心 2024年第1期196-202,共7页
为了取消正弦相似性原理中的最小二乘法等中间环节,获得直接固定标准正弦波形所需要的能量信息。借鉴时域概率分布的方法论,从优势互补的角度出发,设计了一种基于Wasserstein距离算法的变压器励磁涌流闭锁方案。该方案采用特征离散化的... 为了取消正弦相似性原理中的最小二乘法等中间环节,获得直接固定标准正弦波形所需要的能量信息。借鉴时域概率分布的方法论,从优势互补的角度出发,设计了一种基于Wasserstein距离算法的变压器励磁涌流闭锁方案。该方案采用特征离散化的方式,提取目标对象和模板信号并转化为状态向量作为样本标签,以此来判别两者之间的能量分布差异,从而达到正弦场景同源识别的效果。理论分析与仿真结果表明,该方法实现简便,不需要频域计算。相比于现有正弦相似性原理,降低了保护流程的复杂程度,具有更强的实际应用价值和速动性能。通过PSCAD/MATLAB平台对现场合闸的录波数据进行测试分析,验证了所提方案对促进变压器保护性能的积极意义。 展开更多
关键词 变压器 Wasserstein距离 差动保护 能量分布 励磁涌流 信号同源 故障电流
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神经肌肉电刺激通过调控白细胞介素6/信号转导子及转录激活子3信号通路促进脊髓损伤后小鼠运动功能恢复
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作者 覃建锋 宋海旺 +3 位作者 孙宝飞 吉杨丹 龙思方 杨丹 《解剖学报》 CAS CSCD 2024年第3期260-267,共8页
目的观察神经肌肉电刺激(NMES)对脊髓损伤后小鼠白细胞介素6(IL-6)/STAT3信号通路的影响,探讨其对运动功能恢复的机制。方法选取SPF级小鼠72只随机分成假手术(sham)组、脊髓损伤组(SCI)和NMES组。利用BMS评分、斜坡实验与电生理(EMG)评... 目的观察神经肌肉电刺激(NMES)对脊髓损伤后小鼠白细胞介素6(IL-6)/STAT3信号通路的影响,探讨其对运动功能恢复的机制。方法选取SPF级小鼠72只随机分成假手术(sham)组、脊髓损伤组(SCI)和NMES组。利用BMS评分、斜坡实验与电生理(EMG)评估小鼠脊髓损伤后肢体运动恢复情况。Western blotting和Real-time PCR检测各组小鼠脊髓组织中相关炎症因子、IL-6/STAT3信号通路与胶质纤维酸性蛋白(GFAP)和脑源性神经营养因子(BDNF)的表达。HE染色观察各组小鼠脊髓形态结构。结果NMES组BMS评分和小鼠斜坡实验均高于SCI组(P<0.05);NMES组小鼠运动诱发电位(MEP)最大振幅高于SCI组(P<0.05);NMES组脊髓组织TNF-α、IL-12A与GFAP表达量均低于SCI组(P<0.05),TGF-β、IL-10与BDNF表达量均高于SCI组(P<0.05);与SCI组相比,NMES组小鼠脊髓空洞较少,脊髓形态修复较好;与SCI组相比,NMES组IL-6/STAT3信号通路蛋白表达均低于SCI组(P<0.05)。结论神经肌肉电刺激通过抑制IL-6/STAT3信号通路发挥抗炎作用,从而促进脊髓损伤后小鼠后肢运动功能的恢复。 展开更多
关键词 脊髓损伤 炎症反应 白细胞介素6/信号转导子及转录激活子3信号通路 神经肌肉电刺激 免疫印迹法 小鼠
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相干累加与AR滤波相结合的舰船轴频电场信号处理方法
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作者 程锦房 谢昌奇 +1 位作者 张伽伟 喻鹏 《国防科技大学学报》 EI CAS CSCD 北大核心 2024年第3期229-236,共8页
针对采用电场传感器阵列测量舰船电场的应用场景,为提升目标轴频电场的信噪比,提出一种相干累加结合自回归(autoregressive,AR)模型滤波的方法对阵列电场信号进行处理。对测量得到的阵列电场信号进行时延补偿后累加,同时对环境电场信号... 针对采用电场传感器阵列测量舰船电场的应用场景,为提升目标轴频电场的信噪比,提出一种相干累加结合自回归(autoregressive,AR)模型滤波的方法对阵列电场信号进行处理。对测量得到的阵列电场信号进行时延补偿后累加,同时对环境电场信号进行AR建模,并利用AR模型参数构造滤波器,以对累加后的信号实施滤波处理。为验证所提方法在低信噪比条件下的有效性,对实测阵列式电场信号进行处理,结果表明,所提方法能够在信噪比为-25.39 dB的条件下有效压制噪声频谱,保留轴频线谱,处理后信噪比提高约21.92 dB。 展开更多
关键词 轴频电场 阵列信号处理 相干累加 AR模型滤波
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基于规则的信号交叉口纯电动公交节能驾驶策略
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作者 李铁柱 谢炳言 +2 位作者 刘天昊 陈海波 王召 《交通运输系统工程与信息》 EI CSCD 北大核心 2024年第4期139-150,共12页
为解决纯电动公交在通过信号交叉口时能耗较大的问题,本文提出一种旨在最小化电量消耗的基于规则的两阶段驾驶策略,能够实现通行策略场景的合理划分选择及充分优化加减速调整曲线凹凸性,同时,不牺牲乘客舒适度和通行时间。在策略第1阶段... 为解决纯电动公交在通过信号交叉口时能耗较大的问题,本文提出一种旨在最小化电量消耗的基于规则的两阶段驾驶策略,能够实现通行策略场景的合理划分选择及充分优化加减速调整曲线凹凸性,同时,不牺牲乘客舒适度和通行时间。在策略第1阶段,结合车辆运行状态和通过车路协同技术获取的交叉口信号相位和时序信息,提出4种交叉口通行策略的划分与判断选择方式,包括匀速通过策略、加速通过策略、减速通过策略和制动停车策略;在策略第2阶段,利用基于XGBoost算法的能耗估算模型和基于加减速特征参数的曲线模型,优化策略场景中匀速过程、加速过程和减速过程的速度曲线;最后,结合VISSIM仿真验证4种通行策略的有效性。结果表明,所提出的策略可以有效减少电量消耗,在4种驾驶场景下,降低了29.8%~34.2%的能耗。此外,分析发现,在经济车速以上和以下的最佳速度节能曲线均为凹凸形曲线,因此,通过对比实验进行不同速度调整范围的最节能曲线凹凸性规律总结,该结论可以为纯电动公交车的节能驾驶提供更易于操作的驾驶引导。 展开更多
关键词 城市交通 节能驾驶策略 速度曲线优化 纯电动公交 信号交叉口 通行场景划分
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两种地电场仪数据形态的对比分析
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作者 陈星星 张建涛 +1 位作者 王明贵 周超 《科学技术创新》 2024年第5期1-4,共4页
选取应城地震监测站ZD9A-2B和GEF-2地电场仪的数据进行对比分析,发现二者记录的地电场正常日变化和各种干扰的形态基本一致。GEF-2地电场仪量程更广,包含的高频信息更丰富,抵抗雷电干扰的能力更强,运行更稳定。由两种仪器观测数据计算... 选取应城地震监测站ZD9A-2B和GEF-2地电场仪的数据进行对比分析,发现二者记录的地电场正常日变化和各种干扰的形态基本一致。GEF-2地电场仪量程更广,包含的高频信息更丰富,抵抗雷电干扰的能力更强,运行更稳定。由两种仪器观测数据计算得到的地电场优势方位角差别不大。研究结果表明,使用高采样率的仪器或有助于发现更多地震孕育过程中产生的脉冲电信号。 展开更多
关键词 地电场仪 脉冲电信号 ZD9A-2B GEF-2
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信号与能量极板层叠方式下的电场耦合式无线电能传输系统
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作者 苏玉刚 邓晨琳 +2 位作者 胡宏晟 邓仁为 李雨蒙 《中国电机工程学报》 EI CSCD 北大核心 2024年第19期7762-7771,I0023,共11页
为了提升共享部分能量通道式的电能与信号并行传输系统在传输极板面积受限的应用场合中的能量传输性能,并实现信号双向高速传输,提出一种信号传输极板与能量传输极板层叠方式下的电场耦合式无线电能传输(electric-field coupled wireles... 为了提升共享部分能量通道式的电能与信号并行传输系统在传输极板面积受限的应用场合中的能量传输性能,并实现信号双向高速传输,提出一种信号传输极板与能量传输极板层叠方式下的电场耦合式无线电能传输(electric-field coupled wireless power transfer,EC-WPT)系统,给出系统拓扑及串扰抑制方法。基于交流阻抗分析法及香农第二定理,建立电能串扰增益、信号传输增益、信号最大传输速率及电能传输增益的数学模型,分析交叉耦合电容对电能串扰增益及信号传输的影响;以降低交叉耦合电容对信号传输增益及信号最大传输速率的影响为目标,给出层叠方式下EC-WPT系统信号传输极板面积及信号支路参数的设计方法。仿真与实验验证了所提出的系统及给出的方法能在较大传输功率下实现系统的信号双向高速传输。所搭建的实验装置实现了在系统输出功率达到520.2 W时,信号正向传输速度为18.64 Mbit/s和信号反向传输速度为19.36 Mbit/s。 展开更多
关键词 磁场耦合式无线电能传输 信号双向传输 电能串扰 参数设计
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三维闪电探测仪信号完整性与地平面电流设计
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作者 李力 周云祥 +1 位作者 李俊 聂成 《气象水文海洋仪器》 2024年第1期115-117,共3页
文章通过电路与系统的信号完整性及地平面电流回路分析设计出噪声较小、线路合理、性能稳定的三维闪电探测仪,研究成果对其他探测设备升级改型与设计制造具有重要参考价值。
关键词 三维闪电 信号完整性 电流分析
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大熔深K-PAW熔池及电弧视觉行为特征分析研究
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作者 贾传宝 李佳鹏 +2 位作者 陈崇龙 张珂谨 周卫鲁 《电焊机》 2024年第2期1-7,共7页
穿孔等离子弧焊接(K-PAW)以其独特的优势,在中厚板的焊接制造中应用广泛,并逐渐向更大厚度的方向发展。然而,随工件厚度增加熔池穿孔出现不稳定等问题,制约了其在实际生产中的应用。分析了14 mm厚304不锈钢在“受控恒定穿孔”控制策略... 穿孔等离子弧焊接(K-PAW)以其独特的优势,在中厚板的焊接制造中应用广泛,并逐渐向更大厚度的方向发展。然而,随工件厚度增加熔池穿孔出现不稳定等问题,制约了其在实际生产中的应用。分析了14 mm厚304不锈钢在“受控恒定穿孔”控制策略下的大熔深K-PAW熔池特征尺寸变化规律和焊接过程中的熔池行为。通过视觉检测与电信号同步采集系统,对大熔深K-PAW过程中熔池的形貌特征进行定量分析,探究在受控脉冲条件下的熔池特征参数变化情况,以及熔池特征与电信号的同步动态行为规律。以初始电流270 A进行焊接,在起弧的前14 s的盲孔阶段,随着电弧热量积累,熔池不稳定,尺寸出现震荡,最大震荡幅度超过10 mm,同时熔池长宽比也在1.0~1.6范围内变化;随着穿孔于第15 s发生,熔池达到平衡,且长宽比在19 s时达到峰值;维孔阶段,熔池保持稳定,形状未发生大变化。综上,可以通过熔池形状变化趋势来区分焊接阶段。比较了不同焊接电流(280 A、275 A、270 A)的盲孔阶段,发现采用较大的初始电流有利于缩短盲孔时间,由270 A时的22.9 s减小到了280 A时的19.8 s,并降低焊接气孔出现的可能性。最后,发现电弧中心与熔池前边缘的距离可以反映穿孔状态。结果验证了“受控恒定穿孔”控制策略的可行性,并验证了通过视觉特征判断焊接阶段及是否穿孔的可行性。 展开更多
关键词 穿孔等离子弧焊接 深熔焊 熔池视觉特征参数 视电信号同步
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机械设备电气故障自动检测系统优化设计
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作者 王淼 《自动化技术与应用》 2024年第4期134-137,168,共5页
当前系统不能有效消除干扰信号,数据采集精度低,影响机械设备电气故障诊断,为此设计一种新的机械设备电气故障自动检测系统。采集电气故障检测数据,提取电气故障特征,根据特征判断机械设备的电气故障原因,计算纠正参数完善电气故障检测... 当前系统不能有效消除干扰信号,数据采集精度低,影响机械设备电气故障诊断,为此设计一种新的机械设备电气故障自动检测系统。采集电气故障检测数据,提取电气故障特征,根据特征判断机械设备的电气故障原因,计算纠正参数完善电气故障检测结果,线性处理电压检测曲线,完成机械设备电气故障检测。测试结果验证,所提系统能够有效消除干扰信号,保证整体功能运行稳定,相对于对比系统,响应时间更短,数据采集精度得到明显改善。 展开更多
关键词 机械设备 传感器 电气故障 信号处理电路 自动检测系统 神经网络
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