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关键词： 光纤放大器   拉曼放大   分布式放大   宽带泵浦   机器学习  

摘要： 拉曼放大可实现对光信号在光纤链路中的分布式放大，具有高增益、低噪声的优异放大性能，是长距离光纤通信系统中的关键技术之一。近年来，为进一步延伸拉曼放大系统光信号传输距离、降低拉曼放大中的相对强度噪声转移、优化并预测拉曼放大系统增益大小、带宽、平坦度等性能参数，多种新型光纤分布式拉曼放大技术得到开发并应用。对近年来新型光纤分布式拉曼放大技术研究进展进行介绍，包括基于超长距离光纤激光器的高阶分布式拉曼放大技术、基于宽带非相干泵浦源的低噪声拉曼放大技术及基于机器学习的智能分布式拉曼放大技术，并梳理了光纤分布式拉曼放大技术的基本发展趋势及改进方向。

关键词： 永磁同步电机   霍尔传感器   位置和速度估计   滑模观测器   最小二乘  

摘要： 永磁同步电机以其功率密度高、可靠性高和易于维护的优势在工业电动车辆领域得到了广泛应用。与配置高精度编码器和无速度传感器算法的永磁同步电机相比，配置霍尔传感器的永磁同步电机兼顾了系统成本和控制性能。然而，在矢量控制方法中，低分辨率的霍尔传感器输出的位置和速度信息精度较差，从而造成电流和电磁转矩的脉动。因此本文提出了一种融合的速度估计方法，采用最小二乘算法不依赖于电机参数输出连续平滑的角度，并基于电机机械运动方程设计滑模观测器实时估计转速，采用方波启动以解决离散位置信息缺失的问题，并对设计的观测器进行李雅普诺夫稳定性证明。最后实验结果验证了所提转速估计方法的正确性和可行性。

关键词： 弱反射光纤光栅   单片机   解调   温度  

摘要： 【目的】本研究旨在设计并搭建一种针对弱反射光纤光栅（WFBG）的传感解调系统，该系统通过创新的测量流程优化，实现对微弱反射信号的高精度采集与处理，旨在提高温度传感的灵敏度和线性度，同时确保系统的稳定性和重复性。【方法】研究中，我们首先构建了一个基于光电转换器的信号采集系统，该系统能够将WFBG的微弱反射信号转换并放大为电压信号。随后，通过单片机实现了对放大后的电压信号的高效采集。引入误差理论并优化重复测量次数，有效降低了随机误差的影响。同时采取措施减少了测量带来的潜在延时，确保快速准确的数据处理。此外，进行了温度响应特性的实验研究，评估系统在30℃-80℃范围内的性能。【结果】实验结果表明，所设计的传感解调系统在温度测量范围内表现出优异的性能。具体而言，系统展现出的温度灵敏度高达11.55 pm/℃，且线性度高达0.99262，这表明了其在温度测量上的高精度和良好的线性特性。此外，系统的稳定性与重复性经过严格测试，进一步证实了其在实际应用场景中的可靠性和有效性。【结论】综上所述，本研究成功设计并实现了一种结构简单、成本效益高的弱反射光纤光栅传感解调系统。该系统不仅在温度传感方面表现出高精度和高稳定性，而且其创新的结构和优化的测量流程也使其适用于弱光栅传感阵列信号的解调。这一研究成果对于推动光纤传感技术的发展具有重要意义。

关键词： Cobalt doped ZnO NPs   Synthesis photocatalysis   Ciprofloxacin   P. capillacea   CCD   RSM  

摘要： In this research, different Co2+ doped ZnO nanoparticles (NPs) were hydrothermally synthesized by an environmentally friendly, sustainable technique using the extract of P. capillacea for the first time. Co-ZnO was characterized and confirmed by FTIR, XPS, XRD, BET, EDX, SEM, TEM, DRS UV-Vis spectroscopy, and TGA analyses. Dislocation density, micro strains, lattice parameters and volume of the unit cell were measured using XRD results. XRD suggests that the average size of these NPs was between 44.49 and 65.69 nm with a hexagonal wurtzite structure. Tauc plot displayed that the optical energy bandgap of ZnO NPs (3.18) slowly declines with Co doping (2.96 eV). Near complete removal of the ciprofloxacin (CIPF) antibiotic was attained using Green 5% of Hy-Co-ZnO in the existence of visible LED light which exhibited maximum degradation efficiency (99%) within 120 min for 30 ppm CIPF initial concentration. The photodegradation mechanism of CIPF using Green Hy-Co-ZnO NPs followed the Pseudo-first-order kinetics. The Green Hy-Co-ZnO NPs improved photocatalytic performance toward CIPF for 3 cycles. The experiments were designed using the RSM (CCD) method for selected parameters such as catalyst dosage, antibiotic dosage, shaking speed, and pH. The maximal CIPF degradation efficiency (96.4%) was achieved under optimum conditions of 39.45 ppm CIPF dosage, 60.56 mg catalyst dosage, 177.33 rpm shaking speed and pH 7.57.

摘要： 应用物联网、移动互联、人工智能等技术手段,构建智能变电站光纤回路数智化运行检修体系,成为提升光纤回路维护的有效手段.从光纤回路信息"看不见、摸不着"到回路可视化,再到诊断智慧化,让"数智眼睛"有效探究了光纤回路的奥秘.

关键词： Terminalia neotaliala   optimization   seed oil   biodiesel   CCD   RSM  

摘要： Non-edible oils are an attractive source for production of biodiesel as they do not impede the availability of foods. In this study, central composite design (CCD) was used to explain the effects of solvent:solute ratio, temperature and extraction time on the yield of non-edible oil from Terminalia neotaliala seed. The solvent used was n-hexane, and response surface methodology was applied to define the optimum process conditions that maximize oil yield. The oil obtained under optimum conditions was transesterified to biodiesel using potassium hydroxide catalyst. American Society for Testing and Materials(ASTM) standards were used in determining the oil's physicochemical properties, and chemical components of the oil and biodiesel were analyzed with Fourier transform infrared spectroscopy and gas chromatography-mass spectroscopy. The model generated for oil yield was significant at p value, R-2, adjusted R-2, and predicted R-2 of <.0001, 0.9044, 0.8565 and 0.6807, respectively. Optimum oil yield was obtained at 90.0 & DEG;C, solvent:solute ratio of 6.89 and 181.67 min. Chemical analysis of the oil showed the presence of carbonyl acid and fatty acid methyl ester (FAME). Total saturated fatty acid was 45.76%, while polyunsaturated fatty acid and FAME components were 34.42% and 4.59%, respectively.

关键词： Multiobjective optimization  

摘要： The engineering parameters of Enhanced Geothermal System (EGS) will directly affect the heat recovery performance and economic benefits. Optimizing the parameters to achieve the best scheme is crucial for promoting the field application of EGS projects. In this paper, a multi-objective optimization method for heterogeneous hot dry rock (HDR) reservoir is proposed. Effective electrical power, flow impedance, and levelized cost of electricity (LCOE) are considered as optimization objectives. A numerical model of heterogeneous HDR is developed based on spatial frequency to determine the response values of the three objective functions. The Plackett-Burman (PB) method is used to compare the influence of different parameters on the objective function. Five significant engineering parameters are selected as decision variables to establish the objective function. The response surface model of the objective function is obtained by central composite design (CCD) fitting, and the Pareto optimal solution set is obtained by Non-dominated Sorting Genetic Algorithm II (NSGA-II). By combining the entropy weight method and satisfaction ranking, the global optimal engineering parameter design for the operation scheme is optimized. The results show that the satisfaction score for the optimization case is 0.7204. Compared with the original scheme, the effective electrical power increased by 1.3642 MW, the flow impedance decreased by 0.001986 MPa/(kg/s), and the LCOE decreased by 0.004584 $/kWh. The research results are helpful in guiding the optimization of the heat recovery process © 2024, The Authors. All rights reserved.

关键词： 相对强度噪声   高精度光纤陀螺   信噪比   调制深度   噪声抑制  

摘要： 光源相对强度噪声是指由宽谱光源中各频率分量相互作用产生的光强波动。相对强度噪声由光源光谱决定，与光功率无关，在高精度光纤陀螺中无法用提高光功率的方法来减小光源相对强度噪声的影响。目前采用的基于光路直接对消的方案在技术上存在一定的困难，难以满足全温条件下使用的要求，本文提出了一种基于双探测器的光源相对强度噪声的方案，实验结果表明该措施有效可行，提高了光纤陀螺精度，降低了最优调制深度，并在理论上可以实现信号强度的自动跟踪，满足全温条件下的使用要求。

摘要： 日前,中油测井C2285作业队经过5天奋战,成功在渤海南部海域完成了半永置光纤布设和水平井吸水剖面测井任务,这也是该项技术在该海域的首次应用.在海洋之下,入井光纤全段皆可实现信号监测,好比"千眼观测通路",可对井下声波、压力、温度等信号进行全过程检测,经数据处理系统即可获得储层流体动态剖面,为制定油藏动态监测及阶段性工艺措施提供了全过程的海量数据支持.

关键词： 模分复用   少模光纤   模式选择耦合器   线性偏振模式  

摘要： 【目的】模式选择耦合器是模分复用光纤通信系统的关键器件。在模分复用光纤通信系统中，模式选择耦合器可以实现不同信号在不同的模式中进行传输，从而增大光纤传输容量。但在制备低插入损耗模式选择耦合器时，由于模式之间的传播常数非常接近，模式选择耦合器的制备难度较大，因此急需一种模式易分离的少模光纤作为模式选择耦合器制备的关键材料，降低模式选择耦合器的制备难度。【方法】本文提出并制备一种新型环芯少模光纤，该少模光纤在通信C波段支持三个线性偏振模LP01、LP11以及LP21。基于模耦合理论，我们分析了模式选择耦合器各参数对模式耦合的影响，并研究了纤芯间距与耦合距离对模式间的耦合规律。【结果】本文采用熔融拉锥的方法制备出LP01、LP11以及LP21的模式选择耦合器，实验结果表明LP01、LP11以及LP21的模式选择耦合器分别在1540 nm、1530 nm和1550 nm处达到最低插入损耗，LP01、LP11以及LP21的模式选择耦合器的最低插入损耗分别为0.10 dB、0.17 dB和0.30 dB，模式转换效率分别为97.72%、96.16%和93.32%，以及LP01、LP11和LP21的模式转换带宽分别为125.0 nm、120.0 nm和35.0 nm。【结论】该研究为模式选择耦合器提供一种新型环芯少模光纤，可降低模式选择耦合器件的制备难度，该低损耗模式选择耦合器在模分复用光纤通信系统具有良好的应用前景。