光纤干涉仪消光比调谐方法

简要介绍了目前超长距离光纤干涉传感系统的发展现状,并在理论上分析了光纤传感系统中的偏振态对消光比的影响以及能够影响光波偏振态的各种因素.将基于光弹效应的挤压型偏振控制器应用于该系统的消光比调谐,给予光纤干涉臂径向应力,动态调谐系统光波偏振态,实现了长距离光纤传感系统的消光比在一点上的调谐.提出了长距离光纤传感系统灵敏度...     

铬鞣液组成的研究方法进展

研究铬鞣液的组成及各种铬配合物在铬鞣过程所起的作用,对于阐明铬鞣机理和实际的铬鞣操作过程有重要的指导意义。对国内外研究铬鞣液组成所采用的主要的研究方法及其研究成果加以总结归纳,并对各种方法的特点作简要评述。     

基于FLOM-PD的集成化光频梳重频锁定技术

为了将光频梳锁定至原子钟以实现光频梳的高精度稳定,提出了一种集成化重复频率锁定系统方案。利用光纤环路光学-微波鉴相器(FLOM-PD)进行光波和微波之间的直接鉴频鉴相。同时,开发了精密反馈控制模块,阐述了其基本原理,搭建了锁定系统,通过高精度频率计采集锁定后激光器脉冲重复频率数据。实验结果表明:该方案锁定后频率短期稳定度和长期稳定度分别达到8.71×10^-12/s、4.95×10^-14/1024 s,实现了整个系统的集成化。     

制革工业中的绿色化学与技术

论述了中国制革工业研究和实施绿色化学与技术的重要性。概述了国内外在绿色皮革化学品的开发和应用, 清洁的制革生产以及制革废弃物利用方面的研究成果, 并提出了今后的发展方向。     

Optical adaptive filtering for Doppler shift simulator

Based on free space laser communication, this article describes the working principle of electro-optical frequency shifting, designs an optical adaptive filtering module, and builds the core module of the dynamic optical Doppler shifting simulator for laser channel. It is expected to be applied to the heaven-ground integrated communication link. In this article, we adopt the electro-optical frequency shifting technique combined with the microwave-light wave. In the 1 550 nm band, the negative feedback algorithm is used to complete the adaptive filtering, which realizes optical Doppler frequency shifting and high-precision locking. The frequency shift range reaches +5.5—+32 GHz, and the analog precision is better than 645 Hz. When the microwave frequency is greater than 13.5 GHz, the signal-to-noise ratio (SNR) of the output optical power reaches 20 dB, which lays the foundation for the next stage space laser communication.     

Performance of differential phase shift keying maritime laser communication over log-normal distribution turbulence channel

Laser communication is essential part of maritime-terrestrial-air intelligent communication/sensor network. Among them, different modulation formats would play a unique role in specific applications. Based on Rytov theory, we discussed system performance of the maritime laser communication with repeated coding technology in several modulation schemes. The closed-form expression of average bit error rate(BER) from weak to moderate atmospheric turbulence described by log-normal distribution is given. Differential phase shift keying(DPSK) modulation, as a potential solution for future maritime laser communication, has attracted a lot of attention. We analyzed the effects of atmospheric turbulence parameters(visibility, refractive index structure coefficient, non-Kolmogorov spectral power-law exponent, turbulence inner scale) and DPSK system parameters(receiver aperture diameter, repeat time) on average BER in detail. Compared with the aperture-averaging effects, the system BER can be well suppressed through increasing repeat time. This work is anticipated to provide a theoretical reference for maritime laser communication systems.     

在4/2随机波动率下正态调和稳态过程模型对期权的定价和对冲

本文把4/2随机波动率添加到用于模拟资产价格的正态调和稳态过程中,得到了一种全新的Lévy随机波动率模型.更进一步地,本文在此基础上还构造了考虑杠杆效应的Lévy随机波动率模型.本文从数学上证明了模型可行性,并且推导了在这种模型下可被半显式表达出来的期权定价公式和对冲策略公式.作为应用,本文还推导了在上面模型下VIX(波动率指数)波动率衍生品的定价公式,最后数值检验证实了模型的实用性.     

单片机便携式电工测量仪

电工参数的测量一般包括电压、电流、功率、功率因素、频率等,而普通的数字万用表仅能测量电压、电流,不能满足电工测量的要求。本文介绍一种以8031为CPU的单片计算机采用钳型电流互感器的便携式电工综合参数测量仪。它可以测量单相、三相的电工参数,具有体积小、功能全、使用方便等优点,功耗10W。主要技术指标如下: 1.测量范围: