Results 41 to 50 of about 997,974 (152)

Intangible drivers of tolerance shape human–elephant coexistence in Southwest China

open access: yesPeople and Nature, Volume 8, Issue 8, Page 2763-2780, August 2026.
Abstract Southwest China is home to a small but rapidly expanding population of Asian elephants (Elephas maximus), whose growth has intensified conflicts with people living in shared landscapes. These conflicts result in substantial economic losses and occasional human casualties. This coexistence paradox—where conservation success leads to significant
Xiaoyu Yu   +4 more
wiley   +1 more source

频闪He-Ne激光高速干涉摄影装置

open access: yes, 1983
用光振子调制连续输出的He-Ne激光,配合转鼓相机,形成了频闪He-Ne激光高速干涉摄影装置。摄影频率达每秒20000幅。配合超高速转镜相机 ...
夏生杰
core   +2 more sources

油纸屏障对变压器局部放电超高频检测信号的影响

open access: yesGaoya dianqi, 2009
受变压器内部复杂结构的影响,局部放电超高频信号在变压器内部的传播特性非常复杂。笔者通过变压器局部放电超高频实验研究,分析了油纸屏障对变压器局部放电被测超高频信号的影响。设计了油中气隙放电、油中沿面放电和油中电晕放电3种局部放电模型,在实验油箱中进行局部放电实验,采用超高频小环天线进行放电信号检测,在有无油纸屏障情况下获得了局部放电超高频信号实测数据,对所测局部放电超高频信号在时域和频域上进行了对比分析。结果表明,油纸屏障对超高频信号幅值衰减及信号功率谱有一定影响。
高红武   +4 more
doaj  

Ultrathin Magnetic–Conductive Heterostructures for Absorption‐Dominant Electromagnetic Interference Shielding

open access: yesRare Metals, Volume 45, Issue 8, August 2026.
ABSTRACT Ultrathin, lightweight, and mechanically compliant electromagnetic interference (EMI) shields are increasingly required for high‐frequency electronic devices. However, conventional metallic shields predominantly rely on conductivity‐driven reflection mechanisms, which become ineffective at reduced thickness and may cause severe secondary ...
Zida Zhang   +7 more
wiley   +1 more source

Magnetization Dynamics Control for Noise Reduction in Fluxgate Sensors

open access: yesRare Metals, Volume 45, Issue 8, August 2026.
ABSTRACT Fluxgate sensors are indispensable for the detection of weak magnetic fields. However, their noise performance remains constrained by an incomplete understanding of the interplay between the high‐frequency magnetization dynamics of the core material and the overall sensor behavior.
Chunyang Mu   +11 more
wiley   +1 more source

高频电压下油纸绝缘系统的局部放电及产气特性研究

open access: yesGaoya dianqi, 2018
高频变压器在提升电能传输效率的同时,也会加速油纸绝缘系统缺陷的劣化进程。为研究油纸绝缘系统在高频电压下的劣化特性,采用柱板模型模拟油纸绝缘的沿面放电缺陷,搭建高频局部放电试验平台,在10、20、30 k Hz电压下采用恒压法进行多组局部放电试验。利用摄像机和罗氏线圈分别记录试验现象和放电信号,分析高频电压下局部放电图谱和产气特性,并与工频局部放电试验的结果进行对比。结果表明:随着频率的提高,油纸绝缘系统的局部放电起始电压显著降低,单位时间内关键气体的产气量明显提高;但在高频电压下 ...
刘思华   +5 more
doaj  

Challenges in Advancing LGBTQ+ Equity and Research in Southeast Asian Countries: A Brief Report

open access: yesSexuality, Gender &Policy, Volume 9, Issue 3, August 2026.
ABSTRACT This brief report provides preliminary findings on the challenges faced by academics, community workers, and other individuals involved in LGBTQ+ rights activism and research in Southeast Asia (SEA), with larger shares of participants from the Philippines, Malaysia, Thailand, and Vietnam.
Viet D. M. Trinh   +2 more
wiley   +1 more source

变压器内典型油纸绝缘缺陷的高频局部放电传播特性研究

open access: yesGaoya dianqi, 2018
基于高频法检测局部放电技术已经相对成熟,为了现场检测和对变压器运行状况做出准确诊断,文中提出了利用高频法检测分析放电信号传播特性的方法。通过建立仿真模型确定了频带选择范围,并建立试验平台,利用多传感器同时测量和采集实时信号,对比研究了局部放电在变压器内部传播后以及在不同位置放电时高频信号的频谱特性。结果表明,高频局部放电检测法能够对变压器缺陷进行高效检测且高频信号变化规律明显,为实际的波形检测提供了试验依据。
王新, 苏欢欢, 高树国, 张鹏
doaj  

Providing regular and frequent maps of losses and gains of farmland birds based on European monitoring data

open access: yesConservation Biology, Volume 40, Issue 4, August 2026.
Abstract Knowledge of species distributions is essential for informing policies on nature conservation and restoration. However, updating them on a regular basis and doing so in a harmonized manner at the international level is difficult. The European Bird Census Council integrated national monitoring data covering 5 years to update farmland bird ...
Sergi Herrando   +54 more
wiley   +1 more source

利用频率叠加的方法实现高重频高压窄脉冲源

open access: yes, 2011
利用传统方法实现高重频高压窄脉冲源受制于的器件性能,因而 提出了频率叠加的新思路。基于超快电子学和频率叠加理论,利用MARX电路产生多路高压窄脉冲,通过同步系统控制多路触发信号延时,使多路脉冲耦合成一路 输出,实现高重频高压窄脉冲输出。实验中两个单路高压窄脉冲的幅度为2.56 kV,宽度为7.13 ns,重复频率为32 kHz,两路脉冲耦合后,输出脉冲幅度为2.46 kV,宽度为7.49 ns,重复频率为64 kHz。该实验验证了设计思路的可行性,实现了输出脉冲重复频率倍增 ...
阮驰   +5 more
core  

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