共查询到17条相似文献,搜索用时 125 毫秒
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《仪表技术与传感器》2016,(7)
针对现代FBG传感监控系统对性能和功能的高要求,设计了一种基于线阵探测器的FBG传感监控仪。以线阵InGaAs探测器为光谱采集终端,S3C6410为核心构建主控制器,经过优化设计实现了高性能信号采集处理、交互显示预警和网络传输等功能。传感监控仪实现了支持大传感器容量,高速、高精度的传感信号分析和智能化,远程化的监控功能。 相似文献
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针对癌细胞突变基因诱导荧光信号弱、光谱覆盖范围宽、现有显微镜不能检测等局限,本文设计了光谱波段为450~800nm、数值孔径为0.95的荧光显微物镜。物镜采用++-结构,因宽光谱、大数值孔径像差校正难度大、透镜片数多、装调困难,前组设置成敏感组分,承载物镜装调的调校功能,承担90%以上光焦度;中间组为弱光焦度组分,用于校正大数值孔径下的二级光谱,显著降低了二级光谱校正元件的加工难度;后组为负光焦度组分,用于平像场和增大物镜的工作距离。物镜的设计参数为:总长58mm、工作距0.21mm、视场0.625mm、倍率40×、数值孔径0.95,结果表明:其像质接近衍射极限,畸变小于0.2%,满足多种癌细胞突变基因的弱信号生物监测设计要求。 相似文献
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由于ADC采样速率的限制,特别是在恶意用户试图模拟主用户(PU)以阻止次用户(SU)接入空闲授权频谱的情况下,使得认知无线电网络(CRN)中的宽带频谱感知技术面临着极大的技术挑战。针对这些问题,本文提出一种基于随机矩阵理论的压缩宽带频谱感知方法(RMT-CWSS)。RMT-CWSS算法利用随机矩阵理论直接对压缩观测数据进行处理,无需重构出原信号即可实现对宽带频谱进行感知。同时,为了减轻次用户在数据获取和频谱感知过程中的开销,本文提出一种基于传感器节点(SN)辅助感知的合作频谱感知架构。理论分析与仿真结果表明,在存在恶意用户模拟主用户进行攻击的情况下,与传统的基于RMT的宽带频谱感知方法相比,该算法具有复杂度更低、感知性能更好、更稳定等优点。 相似文献
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列举了多种实例,对光学薄膜宽带监测方法作了认真探讨。在非λ/4多层薄膜的制备中,有效的监测方法是获得制各成功的关键。根据宽带光学薄膜的特殊要求,选择合适的监测方法,满足膜层监测的实际需求,是评价实施方法的一个重要依据。 相似文献
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An optical fiber refractive index sensor based on fiber loop ring-down spectroscopy and a tapered fiber was fabricated using an ordinary single mode fiber with an arc fusion splicer. The performance of the sensor was controlled by the parameters of the tapered fiber. A fiber loop ring-down spectroscopy system was employed to enhance the sensitivity and demodulate the transmission spectrum. The results showed that a sensor with a waist diameter of 14 m and a length of 1.2 mm had good optical performance. By monitoring the ring-down time of the system, relatively high sensitivity of 411.576 s/ RIU was achieved with refractive index values from 1.333 to 1.412. This sensor offers few interferences, high sensitivity, easy fabrication, and low cost. 相似文献
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Pearson JC Drouin BJ Maestrini A Mehdi I Ward J Lin RH Yu S Gill JJ Thomas B Lee C Chattopadhyay G Schlecht E Maiwald FW Goldsmith PF Siegel P 《The Review of scientific instruments》2011,82(9):093105
We report the first demonstration of a continuous wave coherent source covering 2.48-2.75 THz, with greater than 10% instantaneous tuning bandwidth and having 1-14 μW of output power at room temperature. This source is based on a 91.8-101.8 GHz synthesizer followed by a power amplifier and three cascaded frequency triplers. It demonstrates for the first time that purely electronic solid-state sources can generate a useful amount of power in a region of the electromagnetic spectrum where lasers (solid state or gas) were previously the only available coherent sources. The bandwidth, agility, and operability of this THz source have enabled wideband, high resolution spectroscopic measurements of water, methanol, and carbon monoxide with a resolution and signal-to-noise ratio unmatched by any other existing system, providing new insight in the physics of these molecules. Furthermore, the power and optical beam quality are high enough to observe the Lamb-dip effect in water. The source frequency has an absolute accuracy better than 1 part in 10(12) and the spectrometer achieves sub-Doppler frequency resolution better than 1 part in 10(8). The harmonic purity is better than 25 dB. This source can serve as a coherent signal for absorption spectroscopy, a local oscillator for a variety of heterodyne systems and can be used as a method for precision control of more powerful but much less frequency agile quantum mechanical terahertz sources. 相似文献
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为了有效监测城市轨道交通钢轨实时状态,确保列车运行过程中轨道信号采集能力和交通运行安全,提出了基于光纤感测技术的城市轨道交通钢轨状态实时监测方法。通过光纤光栅传感器,对钢轨各个状态信号进行了连续采集,采用光栅解调仪全光谱扫描后,传送至监控模块接收状态信号。利用小波变换,对钢轨高频、低频时间和频率进行了细化处理。通过小波包分解转换后的信号,结合小波包能量谱,分析了该频带上的高频和低频信号。依据频带信号总能量的变化情况监测钢轨,并将监测后的数据存储至数据库,实现了城市轨道交通钢轨状态实时监测。测试结果表明,该方法的光学损耗低于 0.8% ,迟滞误差均低于 0.8% ,能够采集列车运行过程中的轨道的高频段和低频信号,有效分析异常能量变化位置。 相似文献