Results 51 to 60 of about 3,986 (106)

SPD残压测量回路中差模干扰问题

Dianci bileiqi, 2008
为了解决限压型SPD残压测量波形严重畸变上凸、幅值偏大的现象,进行了理论计算、EMTP-ATP程序仿真、新旧同轴电缆对比试验和人为将新电缆屏蔽层末端强行接地的试验,结果表明:相同引线长度,相同8/20冲击电流幅值情况下,理论计算、EMTP-ATP程序仿真、新电缆屏蔽层不接地测量残压波形符合要求,引线在SPD上端电压降（U′AB）等于引线在SPD下端的（UAB）;人为将新电缆屏蔽层末端强行接地或破损同轴电缆呈现SPD残压波形严重变形上凸,冲击电流幅值越大,上凸越严重,引线在SPD上端时的电压降（U′AB ...
向念文, 王建国, 薛健, 孙振, 陈俊杰, 方春华, 刘洋, 周密   +7 more
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组合波负峰对浪涌防护影响研究

Dianci bileiqi, 2017
组合波是电涌保护器性能试验与浪涌抗扰度试验的必备波形,但是目前IEC和IEEE相关规范针对组合波的定义存在一定差别,主要在于波形是否存在负峰,因此需要组合波负峰存在与否对浪涌防护的影响。利用EMTP软件搭建两种组合波发生电路,分别产生不存在负峰与存在负峰的组合波,同时结合IEEE压敏电阻模型进行仿真冲击,分析压敏电阻残压与吸收能量的差异。最后讨论不同负载性质下连接电缆长度对两种组合波冲击后负载端电压的影响。分析结果表明:组合波负峰存在与否对压敏电阻残压数值影响不大,但对残压波形影响较大 ...
武海军
doaj  

烧结降温速率对ZnO压敏陶瓷电性能的影响

Dianci bileiqi
氧化锌（ZnO）压敏陶瓷是金属氧化物避雷器的核心元件。ZnO电阻片的残压比、电位梯度、漏电流等性能参数与避雷器的保护性、可靠性、轻便性有着直接关联。通过调控ZnO电阻片在烧结降温过程中900 ℃ — 400 ℃温度区间内的降温速率，实现了残压比、电位梯度和漏电流的协同优化。通过宽带介电温谱，发现本征点缺陷浓度随降温速率增加而增大，锌填隙缺陷浓度的增加相较于氧空位缺陷浓度的增加更为显著。通过解耦残压比和电位梯度的影响因素，发现ZnO电阻片残压比的变化主要受降温速率影响 ...
厍海波, 赵倡皓, 刘扬帆, 王宁, 刘亚芸, 伍建新, 田冰, 艾三, 郭齐睿, 李盛涛   +9 more
doaj  

[Rapid determination of lubabegron residues in animal-derived foods by ultra performance liquid chromatography- tandem mass spectrometry]. [PDF]

Se Pu
Yang C, Zhu WX, Liu YF, Zhang HW, Wei W, Hu K.   +5 more
europepmc   +1 more source

纳秒级脉冲作用下ZnO压敏电阻级间能量配合关系的研究

Dianci bileiqi
针对纳秒级的强电磁脉冲对电力系统的损害问题，基于压敏电阻的特性和瞬变场传输理论，通过改变脉冲注入电压分析不同参数的压敏电阻在20/500-550 ns波形下的响应特征，结合滤波器理论，利用ADS（Advanced Design System）仿真软件进行设计，仿真结果为在频率50 Hz以内插入损耗小于0.3 dB的巴特沃斯低通滤波器，将滤波器串联在两片伏安特性相同的压敏电阻中间进行脉冲注入测试。实验结果表明：随着注入电压的增大，单片压敏电阻的过冲峰值电压逐渐增大，钳位电压基本不变，且与压敏电压呈正相关 ...
李祥超, 郭稳, 王兵
doaj  

[Clinical efficacy of two-stage ear reconstruction using autologous rib cartilage in the correction of congenital microtia]. [PDF]

Zhonghua Shao Shang Yu Chuang Mian Xiu Fu Za Zhi
Xu ZC, Zhang Q, Xu F, Li DT, Li YY, Chen X, Zhang RH.   +6 more
europepmc   +1 more source

[Rehabilitation guidelines and specifications for traumatic spinal cord injury (2025 edition)]. [PDF]

Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi
Professional Committee Of Spine And Spinal Cord Injury Rehabilitation China Association Of Rehabilitation Of Disabled Persons, Professional Committee Of Spine Chinese Association Of Rehabilitation Medicine, The Second Medical-Rehabilitation Integration Working Committee Chinese Association Of Rehabilitation Medicine, Spine And Spinal Cord Injury Repair Study Group The Third Professional Committee Of Neurorestoratology Chinese Medical Doctor Association.   +3 more
europepmc   +1 more source

[Refined surgical protocol and clinical efficacy of total expansion auricular reconstruction surgery]. [PDF]

Zhonghua Shao Shang Yu Chuang Mian Xiu Fu Za Zhi
Hao DY, Song BQ, Dong LW, Cang ZZ.
europepmc   +1 more source

[Effect of lower limb amputation on hemodynamic environment of the left coronary artery: a numerical study]. [PDF]

Sheng Wu Yi Xue Gong Cheng Xue Za Zhi
Tai T, Jiang W, Li Z, Diao J, Li X.
europepmc   +1 more source

[Comparison of effectiveness between endoscopic and microscopic anterior cervical discectomy and fusion]. [PDF]

Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi
Huang C, Chen K, Liu H, Ge Z, Lin D, Chen B, Su G, Lin Y, Hou Y, Li Y.   +9 more
europepmc   +1 more source