基于LED的非相干宽带腔增强吸收光谱技术

介绍了基于可见光波段高功率LED作为光源的高灵敏度宽带腔增强吸收光谱技术,该系统的探测灵敏度通过测量NO₂在472.3～479.3 nm范围内的吸收得到验证。将中心波长为457 nm的高功率LED发出的宽带非相干光耦合进入92.5 cm长、由两片高反射率透镜组成的高精度光学谐振腔内,使用CCD光谱仪(HR2000)测量透过光学腔的光强信号。腔镜在472.3～479.3 nm波长范围内的反射率通过O₂-O₂聚合物的吸收确定,实验测量了一系列低浓度NO₂气体样品,采用差分光谱拟合技术在80 s的平均时间内NO₂浓度反演的统计不确定性约为3.1 ppb(ng·mL-1)。     

具有高机械强度的掺Er3+∶TeO2-Nb2O5玻璃的光谱性质研究

熔制了掺铒碲铌玻璃样品(100-XTeO2-XNb2O5(X=5,10,15,20 mol%),测试了其密度、折射率、转变温度、析晶温度、维氏机械强度、吸收光谱、荧光光谱、荧光寿命等参量。利用Judd-Ofelt和McCumber理论分别计算了铒离子强度参量Ωt (t=2, 4, 6)和受激发射截面σemi的大小,研究了掺铒碲铌玻璃样品光谱参量对Nb2O5成分的依赖性,并与典型的碲锌钠玻璃（75TeO2-20ZnO-5Na2O）在热学、机械强度、光谱性质和放大品行四个方面进行了比较.     

High sensitivity CW-Cavity Ring Down Spectroscopy of N2O near 1.5 μm (II)

We present the second part of the investigation of the high sensitivity absorption spectrum of nitrous oxide by CW-Cavity Ring Down Spectroscopy near 1.5 μm. In a first paper [A.W. Liu, S. Kassi, P. Malara, D. Romanini, V.I. Perevalov, S.A. Tashkun, S.M. Hu, A. Campargue, J. Mol. Spectrosc. 244 (2007) 33-47] devoted to the 6000-6833 cm⁻¹ region, more than 6000 line positions of five isotopologues (¹⁴N₂¹⁶O, ¹⁵N¹⁴N¹⁶O, ¹⁴N¹⁵N¹⁶O, ¹⁴N₂¹⁷O, and ¹⁴N₂¹⁸O), were rovibrationally assigned to a total of 68 bands. The achieved noise equivalent absorption (α_min ∼ 2 × 10⁻¹⁰ cm⁻¹) allowed for the detection of lines with intensity weaker than 2 × 10⁻²⁹ cm/molecule. In this contribution, the investigated region was extended down to 5905 cm⁻¹ and additional recordings allowed accessing small spectral sections uncovered in our preceding recordings. A deeper analysis based on the predictions of the effective Hamiltonian model has allowed assigning a total of 3149 transitions and lowering the percentage of lines left unassigned from 51% to 28%. It led to the analysis of 35, 6, 7, and 6 bands for the ¹⁴N₂¹⁶O, ¹⁵N¹⁴N¹⁶O, ¹⁴N¹⁵N¹⁶O, and ¹⁴N₂¹⁸O isotopologues, respectively. Forty-two of these 54 bands are newly observed, while the rotational analysis of the twelve others is significantly extended and improved. Most of the bands were found unperturbed and their line positions could be reproduced within the experimental uncertainty (about 1 × 10⁻³ cm⁻¹). The corresponding spectroscopic parameters are reported. Local rovibrational perturbations induced by either intrapolyad or interpolyad couplings were found to affect five hot bands of ¹⁴N₂¹⁶O. Their detailed analysis is presented.     

FTIR应用于经染色处理的妇科肿瘤组织切片的研究

应用FTIR分析经染色处理的妇科肿瘤组织切片及常规红外切片,将二者的红外光谱图与正常组织的红外光谱图对照.结果显示,经染色处理的肿瘤组织的各特征峰与未经染色的肿瘤组织的特征峰大体一致,二者与正常组织的红外光谱相比,都具有明显且有规律的差异,说明FTIR直接对经染色处理的肿瘤组织切片进行红外分析以作为肿瘤诊断的依据是可行...     

花生种子品质的可见-近红外光谱分析

利用600～1 100 nm波段研究花生品种的可见-近红外反射光谱,对选取的三种具有代表性的花生种子进行实验。使用近红外光纤光谱仪采集光谱数据,对原始光谱进行小波分析以提取光谱特征,再用主成分分析方法进行聚类分析,最后把每一个样品的前4个主成分得分作为识别模型的输入,品种类别作为模型的输出,以马氏距离作为判别函数,建立了线性判别分析模型。对于每个品种的50个样品,随机挑选30个样本作为训练集,剩余的20个样本作为预测集。该识别模型对3个花生品种的平均正确识别率为95%。表明该方法能有效的识别花生种子,得到较好的分类效果,为花生种子品质的区分和鉴别提供了一种新方法。     

连动型抗干扰干涉具井下瓦斯浓度监测系统（英文）

针对井下甲烷浓度监控干扰大的问题,结合实时监测甲烷浓度的系统要求,设计角镜连动的自消震光学结构,构建了基于无线网络的实时数据通信系统.在干涉系统中,固定两个角镜位置,将两片半透半反镜用连杆结构同步旋转,由此产生光程差.由于采用了连杆结构,任意时刻引入的震动在两个分束镜上等量存在,其结果是差分值,可实现完全相消.由分析分束器的最大旋转范围计算得到系统的光程差变化范围.结合比尔朗伯定律,给出系统在井下工作的甲烷气体浓度最低检出限.分别在实验室及矿井主巷道中完成实验过程,通过化学反应法求得被测甲烷气体的标准浓度,与WQF530型光谱分析仪的测试结果作比较,结果表明:在实验室无干扰条件下,两种检测方法的相对误差均小于1.0%;在井下实验中,传统光学检测方法受环境影响明显,相对误差大幅增加,而本系统测试结果基本稳定,具有较强的抗干扰能力及较高的稳定性.     

胺化葡萄糖及其铜配合物的光谱特性

研究了胺化D-葡萄糖的FTIR,1H-NMR特性及其与Cu(Ⅱ)形成配合物的UV光谱。在FTIR谱中,与D-葡萄糖相比,在1 629～1 608 cm-1出现δ_NH吸收峰,说明D-葡萄糖与乙二胺发生了反应;在1H-NMR谱中,在δ4.82～4.79的化学位移分别对应于葡萄糖C₁上的质子及与C₁直接相连的乙二胺的氨基上的质子,表明反应时乙二胺取代了葡萄糖C₁上的羟基,形成了胺化葡萄糖;在UV谱中,胺化葡萄糖在紫外光区并没有明显吸收,但与Cu(Ⅱ)形成配合物后,在236 nm附近出现最大吸收峰。在胺化葡萄糖-Cu(Ⅱ)配合物中,Cu2+与胺化葡萄糖的络合比接近于1∶1,该配合物稳定常数6.8×107 L·mol-1。     

基于多光谱法的激发温度和辐射温度瞬态测试技术

近些年来,随着国内外尖端科技快速发展,温度测量无论是对于国防建设领域还是对于工业制造领域都有着极为重要的指导意义和研究价值。尤其在瞬态超高温测量方面,测温精度要求更为严苛。测温方法多种多样,多光谱法由于其精度较高且适用性强,被国内外专家广泛运用。基于多光谱测温法,提出一种新的能够同时高精度测量目标的瞬态激发温度和辐射温度的方法。该方法通过查找可信度更高的目标物理特性数据以及更为精确的多光谱直线拟合方法,精准计算得到目标激发温度。通过建立更加准确的数学模型和算法,减小光谱发射率对整个测温过程的影响实现高精度的辐射温度测量。通过相关测温实验表明,系统测温精度达到3%。     

WinCE多线程在微型光谱仪中的应用

Windows CE是一个多任务操作系统,具有占用资源少、实时性特点.CCD作为较高灵敏度的光电传感器被广泛应用在非接触位移领域和光信息测量中.提出通过WinCE多线程编程设计应用软件设计完成嵌入式系统和FPGA配合下的CCD驱动和数据采集;成功的应用在便携式光谱仪的设计中,给出了使用该软件所测得的光谱响应曲线.该软件...     

The absorption spectrum of water between 13 540 and 14 070 cm: ICLAS detection of weak lines and a complete line list

The absorption spectrum of water vapor has been investigated by Intracavity Laser Absorption Spectroscopy (ICLAS) between 13 540 and 14 070 cm⁻¹. This spectrum is dominated by relatively strong transitions of the 4δ polyad of vibrational states. The achieved sensitivity - on the order of α_min ∼ 10⁻⁹ cm⁻¹ - has allowed one to newly measure 222 very weak transitions with intensities down to 5 × 10⁻²⁸ cm/molecule at 296 K. Fifty new or corrected H₂¹⁶O energy levels belonging to a total of 13 vibrational states could be determined from the rovibrational analysis based on variational calculations by Schwenke and Partridge. The previous investigations in the region by Fourier Transform Spectroscopy were critically evaluated and used to construct the best to date set of energy levels accessed by transitions in the considered region. All the rovibrational transitions reaching these upper energy levels and having intensities larger than 4.0 × 10⁻²⁸ cm/mol were calculated. In the resulting line list, the positions at the level of experimental accuracy were augmented with variational intensities leading to the most complete line list for water in normal isotopic abundance in the 13 500-14 100 cm⁻¹ region.