Results 11 to 20 of about 7,096 (202)
Functional Ecology, Volume 39, Issue 11, Page 3255-3268, November 2025.Read the free Plain Language Summary for this article on the Journal blog. Abstract The biotic resistance hypothesis (BRH) of Elton posits that diverse communities are more resistant to biological invasions. While the effects of climatic stresses and human disturbances on community invasibility have been extensively studied individually, their combined
Kai Shi, Misbah Naz, Chi Zhang, Hua Shao
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Spectral Analysis and Application in Weak and High-frequency Signal of Optical Fiber Sensors [PDF]
, 2014 在光纤传感系统中，微弱传感信号和高频传感信号的精确检测一直是研究的热点。微弱的光纤传感信号易受到检测仪器的本底噪声或者外界环境的干扰，经常淹没在噪声中，此时无法对微小传感变量进行精确判断。现今提高光纤传感器系统检测精度的方法大都为对光纤传感器的结构进行改进或对传感信号进行时域的降噪处理。在结构改进方面可以采用低噪声高放大倍数的光电转换电路或在解调系统中引入干涉仪等，但这些方式都会增加的传感系统的成本及复杂度，特别是干涉仪的引用还会降低系统的抗干扰性。对传感信号进行降噪处理如采用小波变换 ...
陈熙
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Rare Metals, Volume 44, Issue 9, Page 6417-6425, September 2025.Graphic abstract Abstract Real‐time detection of acetic acid vapor is of concern for ensuring environmental and personal safety. However, acetic acid gas sensors, particularly those based on Bi2O3, often fail to meet practical performance requirements owing to their slow response characteristics and high operating temperature.
Fan Yang +6 more
wiley +1 more source
The Research and Design of Planar Lens Antenna Based Metamaterial Surface [PDF]
, 2015 平面透镜天线因为其制作工艺简单、成本低、易于大批量生产、一致性好等优点，有很大的应用市场，越来越受到工程师的青睐。本文主要是研究平面透镜天线的应用，用平面贴片透镜天线替代三维透镜天线，用平面龙伯透镜天线替代三维龙伯透镜天线，仿真和测试结果都比较好，在一定程度上改进了现有的研究成果。 在平面贴片透镜天线的研究上，本文研究了只需要一种贴片单元，只需要改变贴片大小和单元极化方向，就可以获得360◦的全相位相应，而传输系数|S11|只改变2dB。之后设计了一款有96个贴片单元组成的平面贴片透镜天线 ...
熊小平
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Rare Metals, Volume 44, Issue 3, Page 1833-1843, March 2025.Graphical abstract AbstractThe pressing demand for ultrathin and flexible shields to counter electromagnetic interference (EMI) has sparked interest in Ti3C2Tx MXene materials due to their exceptional electrical conductivity, tunable surface chemistry, and layered structure.
Zhao‐Yang Li +5 more
wiley +1 more source
Gaoya dianqi, 2023 一般认为，干式空心电抗器的噪声频谱为谐波电流各频率之间的差频、合频及每个谐波的二倍频，然后实际测试得到的噪声频谱与目前理论分析的结果并不一致。文中以一台小型的干式空心电抗器为例，对噪声测量过程中的干扰现象进行了研究，并结合电磁感应理论对干扰的来源进行了解释和分析。研究结果表明，干式空心电抗器在加载单频的激励电流时，利用传声器测得的噪声频谱中除了电流频率二倍频的噪声分量外，还会出现多个电流整数倍频率的干扰分量。其中单倍频的干扰分量来源于磁场对传声器的影响，其幅值和加载电流成正比 ...
陈硕 +4 more
doaj
Research of FM Underwater Acoustic Voice Communication under Multi-path Channels [PDF]
, 2015 随着人类对海洋大规模开发的不断深入，海洋的开发和科研工作对海洋信息传输的需求愈发迫切。大量海洋资源勘探、海洋开发和军事活动等对水声语音通信的需求使得水声语音通信技术日益受到重视。然而水声信道复杂的时空变化特性、多径效应、强噪声等恶劣条件对高性能水声语音通信的研究和设计带来了极大的挑战。 调频(FM,FrequencyModulation)技术是继单边带调制(SSB)后被普遍运用的一种水声语音通信调制解调方法，其具有抗干扰性能好、易于实现等特点。然而，由于浅海信道所具有的强多径、强背景噪声等恶劣条件 ...
曾堃
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Veterinary Dermatology, Volume 35, Issue 6, Page 736-744, December 2024.Background – Topical therapy is preferred for otitis externa (OE) in dogs, and otic products commonly contain glucocorticoids that can be systemically absorbed and possibly interfere with diagnostic tests such as intradermal testing (IDT). Hypothesis/Objectives – To determine the effect of a long‐lasting otic solution containing mometasone furoate (MF)
Jennifer L. Clegg +2 more
wiley +1 more source
Study on Millimeter-Wave Collision Avoidance Radar Based On Digital Beamforming [PDF]
, 2016 近年来，随着交通情况的日益复杂及人们对安全性的要求越来越高，防撞雷达的研究也进入一个快速发展的时期，不断涌现出新的方法和理论。防撞雷达常见的探测方式有超声波、激光等方式。这些方式存在穿透能力较差、作用距离近等缺点，实际工作效果并不是很好。毫米波方式波长短、抗干扰能力强，在雨雪天气下工作良好，且硬件设备具有体积小、重量轻的特点。另外，由于线性调频连续波雷达具有距离分辨率高、结构简单、无距离盲区等优点，因此，基于线性调频连续波方式的毫米波雷达在防撞雷达中得到广泛采用。 目前 ...
庄景波
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Integrative Conservation, Volume 3, Issue 1, Page 36-45, March 2024.Threatened and endangered species that occur in coastal areas are susceptible to the impacts of hurricanes that can destroy and reorganize their habitats. We used long‐term tracking of endangered beach mice to reveal they survive these impacts by using high elevation dune habitats to stay safe.
Michael V. Cove +5 more
wiley +1 more source