Results 11 to 20 of about 7,311 (206)

Based on baseband chip developed navigation interface card [PDF]

open access: yes, 2016
北斗卫星导航系统是我国自主的卫星导航系统,可为分布在我国及周边地区的用户提供定位、短报文通信及授时服务。本文通过对国外GPS导航系统的分析,结合当前国内北斗用户发展现状及军事需求分析,提出相关战术技术指标,完成方案研制。 本文所定义的导航板卡是将天线的信号进行分路后分别进入射频部分进行处理,然后将下变频后的RNSSB3/B1、GPS的L1频点和Glonass的F1频点的中频导航信号送入基带单元进行处理,以完成对卫星导航信号的捕获、跟踪、PVT解算和授时等,该方案是基于北斗区域信号和卫星导航产品规模化 ...
邵留伟
core  

Robust metrics for quantifying and comparing resistance and recovery in experimental studies

open access: yesMethods in Ecology and Evolution, Volume 17, Issue 1, Page 6-14, January 2026.
Abstract Various indices have been developed to experimentally quantify resistance and recovery (two components of engineering resilience) in response to anthropogenic and natural disturbances. This diversity complicates the selection of appropriate metrics for comparing resilience across ecosystems and studies.
Zewei Zhuang   +2 more
wiley   +1 more source

Spectral Analysis and Application in Weak and High-frequency Signal of Optical Fiber Sensors [PDF]

open access: yes, 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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Aridity and grazing are associated with reduced trait complementarity and higher invasion intensity of Solanum rostratum in native plant communities

open access: yesFunctional 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
wiley   +1 more source

The Research and Design of Planar Lens Antenna Based Metamaterial Surface [PDF]

open access: yes, 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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Structural design of highly permeable Bi2O3 microspheres decorated by Pt‐nanoparticles: facile synthesis and acetic acid sensing performance

open access: yesRare 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

Research of FM Underwater Acoustic Voice Communication under Multi-path Channels [PDF]

open access: yes, 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
core  

Comparative enhancement of H+ and OH− treatment on electromagnetic interference shielding in aligned and compact Ti3C2Tx MXene film

open access: yesRare 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

The study of electrochemical glucose sensor with high performance [PDF]

open access: yes, 2016
葡萄糖浓度的定量分析无论是对临床诊断,还是生态工程等众多领域均有至关重要的意义。尤其在临床方面,糖尿病已成为当今社会仅次于癌症和心脑血管疾病的第三大多发性疾病,特别的是由其可引出多种危害较大的并发症。每年糖尿病患者的数目都在不断增加,尤其是我国的糖尿病患者增速不可忽视。尽管没有完全治愈的方法,但是患者通过实时检测葡萄糖浓度可以有效避免并发症的发生。因此,开展快速精确实时地检测葡萄糖浓度的研究十分迫切。 电化学葡萄糖传感器凭借其特有的优势在众多检测技术中倍受青睐 ...
王丹丹
core  

Long‐lasting otic solution containing mometasone furoate can influence intradermal testing in dogs with healthy ears and otitis externa

open access: yesVeterinary 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

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