4296—4302 cm–1范围内氨气光谱线强与自展宽系数测量研究

由于HITRAN数据库中NH₃在4296—4302 cm^–1范围的谱线参数主要源于理论计算,与实际情况存在差异.为了修正数据库中该范围内NH₃的谱线参数,本文利用可调谐二极管激光吸收光谱(TDLAS)技术和计量学理论,测量2—10 Torr(1 Torr=133.322 Pa)高纯NH₃在4296—4302 cm^–1范围内的吸收光谱,综合考虑压强、温度、气池光程、波数、线型拟合等主要影响因素,对NH₃在该波段的主要吸收谱线的线强和自展宽系数进行了反演和不确定度计算.测量得到的线强与同行最新测量结果偏差在20%以内,自展宽系数与HITRAN2020数据库偏差在14%以内,二者的不确定度范围分别为0.63%—2.7%和0.77%—5.4%,均小于HITRAN数据库中的不确定度范围10%—20%,测量的部分谱线光谱参数在HITRAN中没有记录,本文获得的结果对于补充和修正HITRAN数据中4296—4302 cm^–1范围NH₃     

拉脱法测液体表面张力系数的误差分析

对拉脱法测量液体表面张力系数实验的原理和仪器做了简要的介绍,并着重对该实验误差的来源进行了分析探讨。     

偏置调幅波调制下的单模激光光强关联函数随时间的演化（英文）EI北大核心CSCD

采用线性近似法计算了单模激光损失模型在输入偏置信号的调幅波时的光强关联函数C(t).发现光强关联函数C(t)随时间t的演化存在多种变化形式(不规则周期递增、递减等多种振荡形式).结果表明:当a0=0.1时,出现平坦的不规则周期性振荡;低频调制信号频率Ω可调整不规则周期振荡的周期;量子噪音强度Q和高频载波信号频率ω能改变曲线C(t)的初始值和周期.     

测量铜电阻的温度系数的方法与分析

利用非平衡直流电桥分别测量升温和降温过程中铜电阻的温度系数并对这两种方法进行分析比较。     

Narrow-linewidth BaGa4Se7 optical parametric oscillator

The linewidth of the BaGa₄Se₇(BGSe) optical parametric oscillator(OPO) was narrowed for the first time, to the best of our knowledge, by inserting a Fabry–Perot(FP) etalon into an L-shaped cavity. When a 15 mm long BGSe(56.3°, 0°) was pumped by a 1064 nm laser, the peak wavelength was ～3529 nm, and the linewidth was 4.53 nm(3.64 cm^-1) under type I phase matching. After inserting a 350 μm thick FP etalon, the linewidth was decreased to 1.27–2.05 nm. When the tilt ...     

霍尔位置传感器法测杨氏模量实验装置的改进

利用力敏传感器原理解决了霍尔位置传感器测杨氏模量在增加砝码时人为造成刻线晃动的问题。同时,在望远镜下设置导轨,大大增加刻线清晰度的调节。     

车载被动差分吸收光谱在城市道路空气污染监测中的应用

初步探索了一种基于自然光源的移动式车载被动差分光学吸收光谱仪测量系统,并在对合肥市区道路空气污染监测的实验中得到成功应用.该系统采用天顶散射光-被动差分吸收光谱(DOAS)技术对道路上方空气污染进行采样分析,同时结合GPS接收机采集实时经纬度坐标.通过时间信息对两者进行关联,利用GPS接收机定位坐标,并结合合肥市交通地图,依据光谱反演污染气体NO2的柱密度结果绘制整个城市道路上方污染气体浓度图.实验监测路段的NO2垂直柱密度与背景点(解放军电子工程学院校园)监测值之差为6.4×1014 molecule/cm2～1.96×1016 molecule/cm2,由于受到车辆类型、车流量等因素的影响,监测路段总体呈现东北方向平均浓度高于西南方向.     

Experimental damage thresholds of a laser suppression imaging system using a cubic phase plate

The development of laser systems leads to an increasing threat to photoelectric imaging sensors. A cubic phase plate wavefront coding imaging system is proposed to reduce the risk of damage owing to intense laser radiation. Based on the wavefront coding imaging model, the diffracted spot profile and the light intensity distribution on the observation plane are simulated. An experimental device is set up to measure the laser-induced damage thresholds and investigate the morphology of laser-induce...     

Temperature tuning of BaGa4Se7 optical parametric oscillator

The temperature tuning of BaGa₄Se₇(BGSe)was demonstrated for the first time,to the best of our knowledge.When the temperature of BGSe(56.3°,0°)was raised from 30℃ to 140℃,the idler light under type Ⅰ raised from 3637 nm to 3989 nm,the tunable range reached 352 nm,and Δλ₂=ΔT reached 3.20 nm/℃.We calculated the phase matching curve of BGSe when Φ and T took different values.The relationship between θ and Δλ₂=ΔT was obtained by fixing Φ at 0°.The maximum Δλ₂=ΔT and its corresponding(θ,Φ)phase matching type were reported under different fixed λ₂(3μm,3.2μm,...,5μm).     

光电探测器阵列型激光告警系统信号分选与码型识别算法的设计

针对光电探测器阵列型告警系统的体制特点,在分析已知编码规律的基础上,提出了一种基于激光脉冲到达时间的综合信号分选和码型识别算法。通过对该算法采用C＋＋语言进行仿真表明：该算法具有处理速度快、精度高的特点,能显著提高系统的信号分选和码型识别能力。