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High-efficiency and high-power single-frequency fiber laser at 1.6μm based on cascaded energy-transfer pumping

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Photonics Research 2020年第3期8卷 414-420页

作者： XIANCHAO GUAN QILAI ZHAO WEI LIN TIANYI TAN changsheng yang PENGFEI MA ZHONGMIN yang SHANHUI XU School of Physics and Optoelectronics South China University of TechnologyGuangzhou 510640China State Key Laboratory of Luminescent Materials and Devices and Institute of Optical Communication Materials South China University of TechnologyGuangzhou 510640China Guangdong Engineering Technology Research and Development Center of High-performance Fiber Laser Techniques and Equipment Zhuhai 519031China Hengqin Firay Sci-Tech Company Ltd. Zhuhai 519031China Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied Techniques South China University of TechnologyGuangzhou 510640China Guangdong Engineering Technology Research and Development Center of Special Optical Fiber Materials and Devices Guangzhou 510640China

In this paper,a technique combining the cascaded energy-transfer pumping(CEP)method and master-oscillator power-amplifier(MOPA)configuration is proposed for power scaling of 1.6-μm-band single-frequency fiber lasers(SFFLs),where the Er^(3+)ion has a limited *** CEP technique is fulfilled by coupling a primary signal light at 1.6μm and a C-band auxiliary *** numerical model of the fiber amplifier with the CEP technique reveals that the energy transfer process involves the pump competition and the in-band particle transition between the signal and auxiliary ***,for the signal emission,the population density in the upper level is enhanced,and the effective population inversion is achieved thanks to the CEP.A single-frequency MOPA laser at 1603 nm with an output power of 52.6 W and an improved slope efficiency of 30.4%is experimentally obtained through the CEP ***,a laser linewidth of 5.2 k Hz and a signal-to-auxiliary laser ratio of 60.7 d B are obtained at the maximum output *** proposed technique is anticipated to be promising for increasing the slope efficiency and power scaling for fiber lasers operating at L band.

关键词： fiber pumping power

Complex Algorithms for Lattice Adaptive IIR Notch Filter

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Complex Algorithms for Lattice Adaptive IIR Notch Filter

广义稳健中国剩余定理及其在空间欠采样信号DOA估计中的应用

2012 4th International Conference on Signal Processing Systems(ICSPS 2012)

作者： Hong Liang Ning Jia changsheng yang College of Marine Northwestern Polytechnical University

The problem of detecting the complex narrowband signal using complex adaptive IIR notch filter is investigated. In this paper, three complex coefficient adaptive IIR notch filters using gradient-based algorithms are proposed. These three methods are compared among themselves in terms of detecting performance and estimation accuracy. Simulation results show that these proposed algorithms can detect and estimate the frequency of sinusoid, but an "improved" simplified lattice complex algorithm outperforms the other two in the convergence speed, tracking speed and steady-state mean square error at low SNR.

关键词： narrowband signal adaptive IIR notch filter algorithms

来源： cnki会议评论

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西北工业大学学报 2010年第3期28卷 409-414页

作者：梁红张琦杨长生西北工业大学航海学院陕西西安710072

传统的中国剩余定理给出了从几组模数和余数重构正整数的方法,但当余数有误差时重构整数可能存在很大的误差。文中提出了广义的稳健中国剩余定理,采用一组非互质的模数(正整数)和相应的余数为实数且存在误差时重构任意实数的方法,并给... 详细信息

传统的中国剩余定理给出了从几组模数和余数重构正整数的方法,但当余数有误差时重构整数可能存在很大的误差。文中提出了广义的稳健中国剩余定理,采用一组非互质的模数(正整数)和相应的余数为实数且存在误差时重构任意实数的方法,并给出了详细的定理证明,得出算法重构实数的误差仅与余数的误差有关,解决了传统中国剩余定理重构整数时,余数的极小误差可能引起被估计整数相当大误差的问题。首次将该定理用于估计空间欠采样下相邻阵元间距大于半波长,且相位差估计存在误差时信号方位,仿真实验验证了所提算法的正确性和稳健性。

关键词：估计信号处理算法 DOA 广义稳健中国剩余定理空间欠采样

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气水比对曝气生物滤池SND的影响

工业水处理 2011年第8期31卷 63-66页

作者：杨长生成都航空职业技术学院四川成都610021

采用两段BAF处理城市污水,探讨了气水比对反应器处理效果的影响。在A段水力负荷为0.81 m/h、气水比为3：1时,分析了B段气水比分别为3：1、2：1和1：1时反应器的运行情况。结果表明：A段反应器对TN基本上没有去除效果,因NH4＋-N的部分氧... 详细信息

采用两段BAF处理城市污水,探讨了气水比对反应器处理效果的影响。在A段水力负荷为0.81 m/h、气水比为3：1时,分析了B段气水比分别为3：1、2：1和1：1时反应器的运行情况。结果表明：A段反应器对TN基本上没有去除效果,因NH4＋-N的部分氧化使得出水中NO2^--N质量浓度介于0.45-0.70 mg/L之间,NO3^--N质量浓度则介于26.09～41.04 mg/L;B段反应器气水比为2：1时,TN的去除效果最好,平均去除率为50.02%,出水中硝酸盐含量达到最小值。

关键词：气水比同步硝化反硝化曝气生物滤池

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两段上向流曝气生物滤池脱氮性能的研究

工业水处理 2012年第2期32卷 55-58页

作者：杨长生成都航空职业技术学院四川成都610061

对两段上向流曝气生物滤池(UBAF)处理城市污水的脱氮性能进行了研究,探讨了水温、水力负荷、有机容积负荷、NH4+-N容积负荷和气水比对UBAF脱氮性能的影响。试验结果表明:水温是影响UBAF去除脱氮效果的主要因素,随着水力负荷的升高,UBAF... 详细信息

对两段上向流曝气生物滤池(UBAF)处理城市污水的脱氮性能进行了研究,探讨了水温、水力负荷、有机容积负荷、NH4+-N容积负荷和气水比对UBAF脱氮性能的影响。试验结果表明:水温是影响UBAF去除脱氮效果的主要因素,随着水力负荷的升高,UBAF脱氮效果呈下降趋势,当气水比为2∶1时,UBAF对NH4+-N、TN的平均去除效果最好。

关键词：曝气生物滤池水力负荷容积负荷气水比

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工业银粉生产废水处理工艺路线及参数的确定

给水排水 2019年第12期45卷 81-85页

作者：杨长生成都航空职业技术学院

通过对工业银粉生产的不同生产工艺线路的生产废水的水质特性进行分析,提出针对性的分类处理及处理工艺线路;对各处理单元的工艺设计、运行参数的确定进行分析、设计计算,生化处理采用硝化和碳氧化独立设置的AO工艺以及闭环序批式氨氮... 详细信息

通过对工业银粉生产的不同生产工艺线路的生产废水的水质特性进行分析,提出针对性的分类处理及处理工艺线路;对各处理单元的工艺设计、运行参数的确定进行分析、设计计算,生化处理采用硝化和碳氧化独立设置的AO工艺以及闭环序批式氨氮吹脱吸收处理工艺等为工业银粉类生产废水提供参考。

关键词：工业银粉生产废水工艺线路硝化和碳氧化闭环序批式工艺参数

Noise-sidebands-free and ultra-low-RIN 1.5 μm single-frequency fiber laser towards coherent optical detection

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Photonics Research 2018年第4期6卷 326-331页

作者： QILAI ZHAO ZHITAO ZHANG BO WU TIANYI TAN changsheng yang JIULIN GAN HUIHUI CHENG ZHOUMING FENG MINGYING PENG ZHONGMIN yang SHANHUI XU State Key Laboratory of Luminescent Materials and Devices and Institute of Optical Communication Materials South China University of Technology Guangzhou 510640 China College of Optoelectronic Technology Chengdu University of Information Technology Chengdu 610225 China Guangdong engineering Technology Research and Development Center of High-Performance Fiber Laser Techniques and Equipments Zhuhai 519031 China Guangdong Engineering Technology Research and Development Center of Special Optical Fiber Materials and Devices Guangzhou 510640 China Guangdong Provincial Key Laboratory of Fiber Laser Materials and Appfied Techniques South China University of Technology Guangzhou 510640 China

A noise-sidebands-free and ultra-low relative intensity noise(RIN) 1.5 μm single-frequency fiber laser is demonstrated for the first time to our best knowledge. Utilizing a self-injection locking framework and a booster optical amplifier, the noise sidebands with relative amplitudes as high as 20 dB are completely *** RIN is remarkably reduced by more than 64 dB at the relaxation oscillation peak to retain below-150 dB∕Hz in a frequency range from 75 kHz to 50 MHz, while the quantum noise limit is -152.9 d B∕***, a laser linewidth narrower than 600 Hz, a polarization-extinction ratio of more than 23 dB, and an optical signal-to-noise ratio of more than 73 dB are acquired simultaneously. This noise-sidebands-free and ultralow-RIN single-frequency fiber laser is highly competitive in advanced coherent light detection fields including coherent Doppler wind lidar, high-speed coherent optical communication, and precise absolute distance coherent measurement.

关键词：噪声边带激光通讯技术发展现状

Densities, Viscosities and Related Properties for Binary Mixtures of Sulfolane + p-Xylene, Sulfolane + Ethylbenzene in the Temperature Range from 303.15K to 353.15K

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Chinese Journal of Chemical Engineering 2004年第4期12卷 537-542页

作者：杨长生马沛生周清 Key Laboratory for Green Chemical Technology of State Education Ministry School of Chemical Engineering and Technology Tianjin University Tianjin 300072 China Key Laboratory for Green Chemical Technology of State Education Ministry School of Chemical Engineering and Technology Tianjin University Tianjin 300072 Chinaensities and viscosities of the binary systems of sulfolane + ethylbenzene sulfolane + p-xylene have been experimentally determined in temperature interval 303.15-353.15 K and at atmospheric pressure for the whole composition range. The excess molar volumes and viscosity deviations were computed. The computed quantities have been fitted to Redlich-Kister equation. Excess molar volumes and viscosity deviation show a systematic change with increasing temperature. Two mixtures exhibit negative excess volumes with a minimum which occurs approximately at x = 0.5. The effect of the size shape and interaction of components on excess molar volumes and viscosity deviations is discussed.

Densities and viscosities of the binary systems of sulfolane + ethylbenzene, sulfolane + p-xylene have been experimentally determined in temperature interval 303.15-353.15 K and at atmospheric pressure for the whole composition range. The excess molar volumes and viscosity deviations were computed. The computed quantities have been fitted to Redlich-Kister equation. Excess molar volumes and viscosity deviation show a systematic change with increasing temperature. Two mixtures exhibit negative excess volumes with a minimum which occurs approximately at x = 0.5. The effect of the size, shape and interaction of components on excess molar volumes and viscosity deviations is discussed.

关键词： density viscosity excess molar volume sulfolane

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基于显著性检测的声呐图像快速降噪研究

西北工业大学学报 2019年第1期37卷 80-86页

作者：金磊磊梁红杨长生西北工业大学航海学院陕西西安710072

声呐图像在获取过程中易受噪声污染,而降噪性能好的算法通常时间复杂度较高。鉴于人类视觉注意机制,将基于流形排序(MR)的显著性检测方法引入声呐图像处理,将图像自动分割为显著区域和非显著区域两部分。对于占比小的显著区域采用三维... 详细信息

声呐图像在获取过程中易受噪声污染,而降噪性能好的算法通常时间复杂度较高。鉴于人类视觉注意机制,将基于流形排序(MR)的显著性检测方法引入声呐图像处理,将图像自动分割为显著区域和非显著区域两部分。对于占比小的显著区域采用三维块匹配(BM3D)算法降噪以保护图像主要信息,对非显著背景区域采用执行效率较高的均值滤波(MF)算法。将所提算法同经典MF,BM3D算法进行主观和客观评价指标对比,结果表明,所提算法在提高图像视觉效果的同时,执行时间较BM3D算法大为减少,可以满足水下航行器实时作业的应用需求。

关键词：声呐图像图像降噪流行排序显著性检测图像分割三维块匹配均值滤波