自发喇曼成像法在线测量流场组分浓度(II)

 介绍了利用自发Raman散射光谱测量低压气流组分绝对浓度的方法，在流动状态下得到了不同压力下的自发喇曼散射光谱，检测最低压力为133帕；对于含N₂氧气流在已知N₂浓度时实时标定检测了O₂的绝对浓度，测量误差小于8%。     

利用喇曼光谱测量氧碘激光器氧发生器的O2（a^1△）产率

利用自发喇曼成像技术实时监测氧碘激光器O2（a^1△）发生器流场组分，得到了发生器气流中O2（a^1△）和O2（X^3∑）以及N2的自发喇曼散射光谱，由此得到了不同条件下的O2（a^1△）产率。测量误差不超过8%。     

正常和异常血清的共振散射光谱

用日本岛津RF-5301荧光分光光度计研究了高甘油三脂、高胆同醇、高血糖血清和正常血清的散射光谱及同一生化指标不同浓度血清散射光谱的规律.实验结果表明,正常血清散射光谱与高血脂和高血糖血清散射光谱的特征峰差异明显,可以据此区分正常和高血糖、高血脂血清;同一生化指标不同浓度血清散射光谱的峰值强度随血脂、血糖浓度的增大而增...     

一种用于UV-A、UV-B波段地基观测的光谱辐射计

研制了一台可以在250 nm~400 nm波段测量绝对光谱辐亮度和绝对光谱辐照度的扫描式光谱辐射计,辐亮度辐照度相对定标准确度2％,可用于UV-A、UV-B紫外波段地基观测.通过在云南丽江地区(26°52＇N,100°13＇E)开展的大气散射光谱辐亮度和地面太阳直射紫外光谱辐照度观测试验,进一步检验了仪器的性能.观测数据与利用MODTRAN模式模拟计算值存在约8％的偏差,分析了产生偏差的相关因素.     

利用喇曼光谱测量氧碘激光器氧发生器的O2（a1Δ）产率

 利用自发喇曼成像技术实时监测氧碘激光器O₂(¹Δ)发生器流场组分，得到了发生器气流中O₂(¹Δ)和 O₂(X³Σ)以及N₂的自发喇曼散射光谱，由此得到了不同条件下的O₂(¹Δ)产率，测量误差不超过8%。     

改进的红外辐射-量热法测量O2(1△)绝对浓度

对应用于单重态氧发生器 (SOG)O2 (1 △ )绝对浓度测量的红外辐射 量热法从理论和实验两方面进行了改进 ,修正了过去忽略O2 (1 △ )温度变化所造成的系统误差 .此外 ,还详细介绍了在短时间工作的SOG上进行O2 (1△ )绝对浓度测量所必须的自动平衡电桥装置 ,并通过氧气热容的测量检验了它的可靠性 .最后的误差分析表明 ,O2 (1 △ )绝对浓度的相对误差为± 16% ,误差主要来源于光度池红外信号、压力和温度的测量 .     

4-(2-吡啶偶氮)-间苯二酚的共振散射光谱研究

研究了4-(2-吡啶偶氮)-间苯二酚(PAR)水溶液的共振散射光谱的形成机理与影响因素。在弱酸性溶液中,PAR可产生很强的共振光散射, 散射光谱形状与吸收光谱有关。溶液酸度影响PAR的电离平衡和存在状态,因而影响散射光谱。在pH 3.1～6.2之间,PAR为不带电荷的中性分子,可在疏水力的作用下结合形成分子聚合体,从而导致共振光散射增强。光偏振实验表明PAR的散射光为完全偏振光。在一定实验条件下,光散射强度与PAR浓度之间存在线性关系。     

COIL中稀释气体对单态氧产率影响的实验研究

 利用自发Raman散射光谱对射流式氧发生器的单态氧产率进行了测试，研究了稀释气体对于发生器产率的影响，并分析了造成影响的原因     

纳米材料在乳制品三聚氰胺检测中的应用进展

主要综述了纳米材料在乳制品三聚氰胺检测中的研究进展.对以纳米材料为基础或与纳米材料相关的三聚氰胺检测的新方法进行了介绍,其中包括比色法、荧光光谱法、共振光散射光谱法、表面增强拉曼散射光谱法、电致化学发光法和毛细管电泳法.     

利用喇曼光谱测量氧碘化学激光器氯气利用率的实验研究

 介绍了利用自发喇曼散射光谱测量氧碘化学激光器单态氧发生器氯气利用率的原理及实验装置，并给出了在以氮气作为稀释气的0.1mol/s射流式氧发生器上测试的结果，测试相对误差小于12%。由于该方法只需要通过测量喇曼谱线相对强度之比，即可算出氯的利用率，因此不需要另外的标定实验，从而避免了因标定带来的影响。该方法减小了测试误差，简化了实验过程，提高了测试效率。     

自发喇曼成像法在线测量流场组分浓度

 介绍了自发喇曼成像技术实时监测流场组分浓度的方法,利用Nd：YAG脉冲激光器以及ICCD和光谱仪对大气进行了不同实验条件的测试,得到了影响谱线强度及测试精度的几个因素;得到了大气流场各主要成分的自发喇曼散射光谱和绝对浓度,测量误差小于8%。该技术可望在氧碘化学激光器单重态氧发生器物种浓度测定时得以应用以改善O₂(¹Δ)浓度测试精度较低的现状。     

Surface plasmon interferometric microscopy for three-dimensional imaging of dynamic processes

A method, which we named surface plasmon interferometric microscopy, for real-time displaying of the dynamic evolution of the refractive index (RI) of a sample in three-dimensions is demonstrated experimentally. The Fourier fringe analysis technique is employed to get the phase variations of the samples by demodulating the interference patterns captured by a CCD camera, and the 3D RI distribution can be obtained through numerical interpolation from the relation between the phase and the RI of the samples. Our method may provide an interesting way to monitor fast dynamics of physical, biological, and chemical processes in real time.     

光纤光栅压力传感器在列车实时追踪系统中的应用

随着外界应力的变化 ,光纤光栅的Bragg中心反射波长将发生相应的移动。利用此特性 ,与计算机监控相结合 ,研制出一种光纤光栅压力传感系统 (FBG) ,测量时间约 1ms/点 ,该系统可广泛用于列车实时追踪 ,实现列车的定位、速度与加速度计算等 ,并可以对列车脱节等事故及时作出判断     

激光除锈过程的实时监测技术研究

对激光除锈过程中的实时监测技术进行了实验研究,结果表明:除锈过程中产生的声波强度会随着表面清洁度的变化而发生明显的变化,声波信号包含了除锈过程中的大量信息,可作为激光除锈实时监测的基本信号.     

Treatment of industrial wastewater effluents using hydrodynamic cavitation and the advanced Fenton process

For the first time, hydrodynamic cavitation induced by a liquid whistle reactor (LWR) has been used in conjunction with the advanced Fenton process (AFP) for the treatment of real industrial wastewater. Semi-batch experiments in the LWR were designed to investigate the performance of the process for two different industrial wastewater samples. The effect of various operating parameters such as pressure, H2O2 concentration and the initial concentration of industrial wastewater samples on the extent of mineralization as measured by total organic carbon (TOC) content have been studied with the aim of maximizing the extent of degradation. It has been observed that higher pressures, sequential addition of hydrogen peroxide at higher loadings and lower concentration of the effluent are more favourable for a rapid TOC mineralization. In general, the novel combination of hydrodynamic cavitation with AFP results in about 60-80% removal of TOC under optimized conditions depending on the type of industrial effluent samples. The combination described herein is most useful for treatment of bio-refractory materials where the diminution in toxicity can be achieved up to a certain level and then conventional biological oxidation can be employed for final treatment. The present work is the first to report the use of a hydrodynamic cavitation technique for real industrial wastewater treatment.     

The Relationship of Cavitation to the Negative Acoustic Pressure Amplitude in Ultrasonic Therapy

The relationship between the cavitation and acoustic peak negative pressure in the high-intensity focused ultrasound(HIFU)Held is analyzed in water and tissue phantom.The peak negative pressure at the focus is determined by a hybrid approach combining the measurement with the simulation.The spheroidal beam equation is utilized to describe the nonlinear acoustic propagation.The waveform at the focus is measured by a fiber optic probe hydrophone in water.The relationship between the source pressure amplitude and the excitation voltage is determined by fitting the measured ratio of the second harmonic to the fundamental component at the focus,based on the model simulation.Then the focal negative pressure is calculated for arbitrary voltage excitation in water and tissue phantom.A portable B-mode ultrasound scanner is applied to monitor HIFU-induced cavitation in real time,and a passive cavitation detection(PCD)system is used to acquire the bubble scattering signals in the HIFU focal volume for the cavitation quantification.The results show that:(1)unstable cavitation starts to appear in degassed water when the peak negative pressure of HIFU signals reaches 13.5 MPa;and(2)the cavitation activity can be detected in tissue phantom by B-mode images and in the PCD system with HIFU peak negative pressures of 9.0 MPa and 7.8 MPa,respectively,which suggests that real-time B-mode images could be used to monitor the cavitation activity in two dimensions,while PCD systems are more sensitive to detect scattering and emission signals from cavitation bubbles.     

空气中O2和N2摩尔分数的拉曼散射多通道测量

开发了一套基于激光拉曼散射的多通道气体光学检测系统,应用于空气中主要组分的摩尔分数定量测量.针对性的设计了532 nm激光脉冲展宽器,能有效地避免脉冲激光在高能量状态下造成气体裂解、石英玻璃损伤等现象的发生,提高了气体拉曼散射的信噪比.在实验室环境压力和温度下,对气体样池内空气进行了长66 mm×直径1 mm激发区域同步10通道(每通道长约6.6 mm)的拉曼散射实验.得到了各通道下氧气(O2)和氮气(N2)的拉曼光谱和摩尔分数,及O2相对于N2的相对响应因子RO2.完成了26次重复性实验,每次为200个激光脉冲激发自发拉曼光谱的累加.结果表明,各通道间计算的平均的氧摩尔分数x-O2和相对于氮气的相对响应因子-RO2的标准偏差分别为0.015和0.024,但它们的平均值与10通道合并方式下的实验结果完全相同,准确率达98%,完全满足实时地并具有时空分辨力的定量测量混合气体摩尔分数的要求.该系统可满足于各种动态燃烧过程的光谱检测与分析.     

实时监测技术在化学合成成分分析中的应用

化学合成成分实时监测技术是一种新颖的化学过程分析方法,可对化学合成成分进行实时动态监测,揭示化学反应发生的微观机理、反应历程和动力学特征,合理确定反应终点,提高反应的选择性、产物质量和收率。阐述了实时监测技术基本结构与原理,综述了实时监测技术在化学合成成分分析中的应用,着重评价了光谱法、色谱法及其联用技术在化学合成成分实时监测中的研究、开发和进展。采用联用技术可发挥色谱的高效分离和定量特性以及光谱灵敏的定性鉴别能力,以实现对复杂体系中特定成分的实时监控。随着微处理器和嵌入式系统的研制,化学合成成分实时分析技术将向微型化、智能化、数字化、功能化且通用性广、兼容性强的多通道组分监测方向发展。     

In situ observation of the ultrafast lattice dynamics of graphite under ion irradiation

We develop a pump-probe experiment system, in which vibrational dynamics of a solid sample under ion irradiation can be measured in real time. In situ observation enables us to monitor small changes induced by ion irradiation, without being influenced by the irreproducibility of the sample quality or the experimental configuration. We apply the experimental system to investigate the femtosecond dynamics of the coherent E_2g1 phonon of graphite under 5 keV He⁺ irradiation. A slight decrease in the dephasing rate of the phonon at the initial stage, as well as a downshift followed by an upshift of the phonon frequency, are clearly demonstrated, all of which were ambiguous in the ex situ experiment due to the poor reproducibility of the surface quality. This technique could also be applied to study femtosecond vibrational dynamics in real time during thermal annealing, film deposition with e.g. ablation and sputter, and molecular adsorption on substrates.