Results 11 to 20 of about 47,024 (140)

空调器室内柜机噪声的空气动力学分析 [PDF]

open access: yes, 2000
本文对目前空调器室内柜机运转所产生的气流噪声从空气动力学的角度给予分析,并进行了相关的试验研究。试验表明 ...
单希壮
core   +2 more sources

1000 kV特高压交流变电站噪声特性及变化规律

open access: yesGaoya dianqi, 2021
以1 000 kV特高压交流变电站为研究对象,连续3年在工况基本相同条件下对同一变压器、高压电抗器以及场界噪声进行了测量统计,分析了变电站主要设备噪声的分布情况,变化规律与衰减特性。结果表明,连续3年主变压器平均噪声分别为72.9、73.4、74.6 dB(A),平均每年递增0.6 d B(A),通过频谱分析得出主变噪声逐年增加主要由于冷却风扇噪声增加所致。连续3年高压电抗器室内平均噪声分别为77.0、77.8、79.1 dB(A),平均每年分别递增0.7 dB(A),室外平均噪声分别为65.7、66 ...
车凯   +6 more
doaj  

Electric Field‐Induced Dark Current Steering in MAPbI3/Nb2CTx Photodetector Toward Weak‐Light Single‐Pixel Imaging

open access: yesRare Metals, Volume 45, Issue 7, July 2026.
ABSTRACT In conventional photoconductive detectors, the shared collection path for dark current and photocurrent imposes a fundamental compromise between noise suppression and signal responsivity. To break this trade‐off, we introduce a device architecture featuring a strategically integrated third electrode within a MAPbI3/Nb2CTx heterostructure. This
Yan‐Wei Lv   +7 more
wiley   +1 more source

特高压交流变压器噪声干涉及衰减特性

open access: yesGaoya dianqi, 2022
变压器外部噪声控制系统对提升变电站声环境质量具有重要意义。噪声控制系统的布放位置和结构参数选择需要依据变压器空间噪声的干涉衰减和频谱特性。目前对变压器不同位置噪声干涉衰减规律的研究很少。文中测量了山西省内某1 000 kV特高压变压器噪声,研究了变压器A、B、C相以及AB、BC相中间位置噪声干涉衰减规律。变压器A、B、C相声压级随测量点到变压器立面距离增加单调下降,略有波动,分为快衰减段和慢衰减段。变压器AB、BC相中间位置,由于近场干涉作用出现明显的振荡段。在振荡段高频分量单调下降 ...
张超, 刘国强, 芦竹茂, 俞华
doaj  

High‐Performance Self‐Powered Ultraviolet Photodetector Based on NiO/La‐Doped SrSnO3/Nb‐Doped SrTiO3 Dual‐Heterojunction

open access: yesRare Metals, Volume 45, Issue 7, July 2026.
ABSTRACT The development of high‐performance photodetectors critically relies on innovative interfacial band engineering, a strategy that enables the synergistic enhancement of photocurrent and drastic suppression of dark current. Herein, a self‐powered ultraviolet (UV) photodetector is demonstrated based on a NiO/La‐doped SrSnO3 (LSSO)/Nb‐doped SrTiO3
Wentian Zhang   +7 more
wiley   +1 more source

A Preliminary Assessment of Noise‐Related Impacts From the Urban‐Invasive Johnstone's Whistling Frog (Eleutherodactylus johnstonei) 城市入侵物种约翰斯通鸣蛙 (Eleutherodactylus johnstonei) 引起的噪声影响初步评估 Una evaluación preliminar de los impactos relacionados con el ruido de la rana silbadora de Johnstone (Eleutherodactylus johnstonei), especie urbana invasora

open access: yesIntegrative Conservation, Volume 5, Issue 1, Page 104-114, March 2026.
The Johnstone's whistling frog is an invasive species whose loud night‐time calls may affect human health and well‐being. Our study in Cali, Colombia, combined fieldwork and online surveys to assess its urban occupancy, density, and potential health impacts.
Rubén Darío Palacio, Sumana Goli
wiley   +1 more source

压气机转子气动噪声声源特性的数值模拟

open access: yes, 2016
航空风扇与压气机气动噪声作为飞机噪声的重要来源而备受关注,尤其是在射流噪声得到降低的情况下。其中包含复杂的非定常流动和气动噪声产生机制,关于其声源的特征,如成分、物理意义等,还缺少实验和数值模拟数据。本文基于现有声学比拟理论,包括Lighithill方程和涡-声理论,结合声源区域计算流体力学高精度模拟,研究NASA风扇转子rotor 67标模在设计工况下的非定常流动和气动噪声声源特征。采用高精度数值方法进行非定常流动模拟,湍流模型采用S-A模型,分析其非定常流动特性,在此基础上利用声比拟理论和涡 ...
申义庆, 杨焱
core   +2 more sources

Composite‐Field Annealing Enables Superior High‐Temperature Noise Stability in Fluxgate Sensors With Co‐Rich Amorphous Microwires

open access: yesRare Metals, Volume 45, Issue 2, February 2026.
ABSTRACT Fluxgate sensors with Co‐rich amorphous microwires, widely used for their low noise in magnetic field measurements, encounter significant challenges in high‐temperature environments such as well drilling and geological exploration. Prolonged thermal aging degrades the performance of Co‐rich amorphous microwires, resulting in increased noise ...
Lining Pan   +10 more
wiley   +1 more source

Domain‐adaptation‐based named entity recognition with information enrichment for equipment fault knowledge graph

open access: yesIET Collaborative Intelligent Manufacturing, Volume 6, Issue 4, December 2024.
Domain‐adaptation‐based named entity recognition with information enrichment is proposed for developing an equipment fault knowledge graph. A question answering application of the equipment fault knowledge graph is proposed. Abstract Numerous files, such as records and logs, are generated in the process of equipment diagnosis and maintenance (D&M ...
Dengrui Xiong   +3 more
wiley   +1 more source

噪声对语音再认的影响

open access: yes, 1987
本实验采用信号检测理论考察了噪声对语音再认活动的影响。结果表明:随着噪声级的增高,即字表声级(65分贝)与噪声级差值的下降,被试对字表的再认能力也降低。这种下降的趋势遵循方程:Y=2.62—0.03X; 在本实验中影响这种下降趋势的因素是字表声级与噪声级的差值(λ)、烦恼度(A)和反应标准(β)。根据多元回归理论,其影响程度:λ>A>β ...
马谋超, 何存道
core   +2 more sources

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