Results 21 to 30 of about 12,197 (133)
Gaoya dianqi, 2019 行波传输速度是影响行波测距精度的关键因素之一,输电线路上暂态行波速度的难以确定严重制约了行波测距精度。对此,文中从优化行波传输速度着手,提出一种多回输电线路行波故障精确测距方法。首先基于波速误差对输电线路行波测距精度的影响,分析了现存行波波速确定方法的优劣。进一步,基于同杆多回输电线路共用输电走廊的结构特点,在非故障线路上实时在线测量出行波速度,并将其应用于故障线路的精确行波测距计算中。理论分析和仿真数据均表明:此方法不受线路参数的影响,能有效克服环境因素给沿线波速带来的误差 ...
田斌 +5 more
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Rare Metals, Volume 45, Issue 7, July 2026.ABSTRACT In this work, In2O3 and three rare earth (RE)‐doped In2O3 composites (Ho, Yb, and Sm‐doped) were prepared via the hydrothermal method. Compared with In2O3 sensors, those fabricated from the three composite materials (RE–In2O3) exhibit varying degrees of enhanced response toward ethylene glycol (EG) gas. At 35% relative humidity (RH) and 250°C,
Chang Liu +9 more
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Gaoya dianqi, 2017 识别第2个反向行波来自故障点还是对端母线是实现单端行波故障测距的关键,对此,提出一种识别第2个反向行波性质的新方法。通过分析4种类型的行波传播路径,得到透射线模行波与非透射线模行波到达测量端的时间顺序,从而辨识出由故障点交叉透射的初始线模行波,再利用初始透射线模行波与第2个线模反向行波之间的极性关系构造了识别第2个反向行波性质的判据。仿真结果表明:所提方法基本不受母线结构、模量衰减和透射模量的影响,具有较好的可靠性。
江雪晨, 张翠玲, 宁一
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Rare Metals, Volume 45, Issue 6, June 2026.ABSTRACT To address the demand for high‐temperature stability, broadband strong absorption, and multifunctional integration of electromagnetic wave absorbing materials in complex service environments, lightweight molybdenum disulfide (MoS2) decorated silicon carbide (SiC) nanofiber composite aerogels with a directional layered interconnected structure ...
Zhi Song +4 more
wiley +1 more source
Gaoya dianqi, 2016 针对行波在电网传输过程中存在畸变现象,文中以某110 k V电网（共计15个变电站节点）为例,对行波传播过程进行了仿真,分析了行波到达时间与传播路径的关系,及各站点行波信号的时频域特性。利用EMD-HHT算法计算得到行波的到达时间,利用动力学理论计算了行波头前0.5 ms（共计1 000个样点）波形的Kolmogorov熵及分维数F,研究发现:行波信号的K熵及分维数F随传播距离增加,呈减少趋势,且邻近线路或环网节点的指数分布数值相近,该结论可定性判断行波源的大致位置。
李毅, 吴政球, 李建奇
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Rare Metals, Volume 45, Issue 6, June 2026.ABSTRACT The development of lightweight, high‐attenuation, and broadband carbon‐based electromagnetic wave absorbers is hindered by the intrinsic trade‐off between impedance matching and dielectric dissipation. Herein, we report a facile and scalable synthesis of N‐doped lignin‐derived interconnected porous carbon (Nx‐LIPC) via hydrogen‐bond self ...
Bin‐Peng Zhang +7 more
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Gaoya dianqi, 2018 为提高输电线路的故障测距性能,笔者综合分析了工频法和行波法二者之间的测距特点,并提出了一种综合应用工频量法和单端行波法的组合故障测距法。首先,基于输电线路的沿线电压幅值分布规律,利用切线交叉的工频测距原理,初步确定故障区域,接着,在此基础上用A型行波法精确地测出故障位置。通过引入行波测距避免工频测距后续的迭代计算,克服迭代不收敛或收敛至伪根的问题,提高测距精度;用工频初步测距,缩小行波波头辨识范围,提高行波测距可靠性。经仿真验证:所提组合法比工频法测距精度更高,比行波法的波头识别更加准确可靠。
李振兴 +4 more
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Rare Metals, Volume 45, Issue 6, June 2026.ABSTRACT Because magnetic permeability is an intrinsic property of materials, achieving the regulation of magnetic loss is one of the challenges for electromagnetic wave absorption materials. This paper focuses on the research idea of in situ growth of dispersed nanocrystalline FeSiB in an amorphous FeSiB matrix to regulate magnetic properties.
Lei Wang +4 more
wiley +1 more source
Structural Modulation of Magnetic Softness in Fe‐Based Amorphous Alloys via Pulse Current Training
Rare Metals, Volume 45, Issue 6, June 2026.ABSTRACT Fe‐based amorphous alloys, despite their intrinsically low magnetocrystalline anisotropy, suffer from quasi‐dislocation dipoles and localized stress fields that impede domain‐wall motion and increase coercivity. Here, we introduce pulse current training (PCT) as an energy‐efficient technique to overcome these limitations in a Fe76Si9B10P5 ...
Shumin Ye +13 more
wiley +1 more source
四川大学学报. 自然科学版, 2015 在线性近似下,Helmholtz方程能够描述小尺度大气声波波动.因此分析小规模大气声波波动特性,必须对Helmholtz方程进行求解.大多数求解Helmholtz方程的方法是在某些边界条件和初始条件下进行的,而边界条件和初始条件本身就是在假设、近似的基础上得到的,且会使得计算过程复杂和计算量变大.指数函数法具有多个自由参数是求解非线性问题精确解的一种十分有效、直接的工具,且在求解时不要考虑边界条件和初始条件,对函数进行指数和双曲正切变换的共同作用可近似为线性变换.基于上述思想 ...
纪娟娟, 郭业才, 张兰芳
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