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论 GPS 与相对论时空观 被引量:1
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作者 齐新 李玉玲 《宇航学报》 EI CAS CSCD 北大核心 1998年第2期109-113,共5页
在GPS中,观测者对时钟所显时间值和物理事件所发光信号传播过程所作全面描述应包括“看到的情况”和“实际的情况”;作为具有特定物质性、运动性、结构性和开放性的动力学系统,时种所显时间值与其内部特定物质性、运动性和结构性... 在GPS中,观测者对时钟所显时间值和物理事件所发光信号传播过程所作全面描述应包括“看到的情况”和“实际的情况”;作为具有特定物质性、运动性、结构性和开放性的动力学系统,时种所显时间值与其内部特定物质性、运动性和结构性等内因有关,与其所受引力和电磁力等外因有关;根据速度值定义,除特别约定,具体光子相对具体参照物的具体速度值应由观测者使用具体时种和量尺观测而定。以上述时空新认识弥补了相对论时空观有关观点的认识不足。 展开更多
关键词 光信号延迟 相对论时空观 全球定位系统 GPS
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An Interrogation System Based on Two Semiconductor Optical Amplifiers for Weak Fiber Bragg Gratings
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作者 Zhihui LUO Hongqiao WEN Huiyong GUO 《Photonic Sensors》 SCIE EI CAS 2014年第2期168-172,共5页
An interrogation system based on two semiconductor optical amplifiers for weak fiber Bragg gratings (FBGs) was proposed. The first semiconductor optical amplifier (SOA) was used to modulate the light, and the seco... An interrogation system based on two semiconductor optical amplifiers for weak fiber Bragg gratings (FBGs) was proposed. The first semiconductor optical amplifier (SOA) was used to modulate the light, and the second SOA separated the reflected signal from the different FBGs through delayed switching. The proposed system has lower insertion loss and higher spatial resolution, and can interrogate the time- and wavelength-division multiplexed FBG array. Up to 50 FBGs, with a reflectivity of 0.2% and a spatial resolution of 5 m along the optical fiber, were distinguished to demonstrate the interrogation system. 展开更多
关键词 Fiber Bragg grating SENSORS time-division multiplexing semiconductor optical amplifiers INTERROGATION
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