利用WGD-3型组合式多功能光栅光谱仪研究温度和高浓度溶液对吸光度的影响规律

利用WGD-3型组合式多功能光栅光谱仪测量不同浓度及不同温度的 NaCl溶液、NaO H溶液和蔗糖溶液对波长为200～800 nm的溴钨灯光的吸光度图谱，分析温度、混合溶液以及溶液浓度与溶液吸光度之间的关系，在稀浓度溶液吸光度的朗伯-比尔定律的基础上，进行对高浓度溶液、高浓度混合溶液的吸光度研究，总结温度和溶液浓度对高浓度溶液吸光度的影响规律，分析产生现象的原因。     

利用核磁共振测量乙醇汽油溶液浓度

利用核磁共振成像分析仪测量了不同汽油体积含量的乙醇汽油溶液的核磁共振信号,分析了横向弛豫时间、信号强度与汽油浓度的关系.结果表明乙醇汽油溶液中汽油的体积含量与信号强度呈线性关系,因此利用低磁场核磁共振可以测量乙醇汽油浓度.     

机器学习在紫外法测定硝酸盐氮浓度中的应用

紫外分光光度法(UV法)由于较传统化学方法具有效率高操作简便、无二次污染且可现场原位测试等优点,近些年来被广泛应用到水质参数的测试中。硝酸盐氮是工业废水中的主要污染物之一。基于UV法测量水体中硝酸盐氮浓度的标准方法是分别测量水样在220nm和275nm处的吸光度,然后用275 nm处的吸光度对220 nm处的吸光度进行校正,进而绘制出校正后的吸光度与硝酸盐氮浓度的标准曲线。然而,当硝酸盐氮浓度升高时,标准法所采用的朗伯比尔定律的线性关系以及不同物质吸光度叠加的线性不能很好地满足,在实际的实验测试中也发现,很难建立硝酸盐氮在220 nm处的吸收模型。为了克服单波长或双波长方法的缺陷,将硝酸盐氮吸收峰范围的各个波长的吸光特性引入到模型的建立之中。同时,为了降低模型的复杂度,在建立模型之前先对吸光度数据进行主成分分析,将输入数据的维度数从107压缩到4,然后对压缩后的数据使用局部加权线性回归法建模,该吸收模型对于训练样本和测试样本都有较好的预测结果,且能够适应高浓度时吸光度与浓度的非线性关系,测量上限可达几百mg·L-1。另外,此方法的原理和流程也适用于其他水质参数吸收模型的建立。     

用紫外光谱法测定共轭亚油酸乙酯的含量

在226-240nm波长范围内，采用紫外可见分光光度法测定了不同浓度的共轭亚油酸乙酯的吸光度，绘制出样品在不同浓度时的吸光度曲线，找出适宜的浓度范围，作线性回归分析，得到样品浓度和吸光度的线性关系。利用PE Autosystem XL-TurboMass测得样品中共轭亚油酸乙酯的准确浓度，结合回归系数给出了测定共轭亚油酸乙酯含量的经验公式。     

光谱法锌离子检测系统的研究

采取标准锌显色剂与锌发生显色反应，生成不溶于水的絮状络合物。用光谱仪测它的吸光度，研究其特征谱与吸光度的特点，建立其浓度与特征波长吸光度间的数学模型。本文所采用的显色剂主要与锌、铜、镉、镍四种离子发生络合反应。因此分别探索了四种离子高浓度以及低浓度时显色反应的吸光度，最终通过得到锌离子浓度与吸光度的关系式以及锌离子浓度与四波长下四种离子混合溶液显色后的吸光度的关系式，给出了锌离子的吸光度与总吸光度的关系式。显色反应能否满足分光光度法的要求，主要与显色剂的性质有关，同时显色反应的条件也至关重要。因为在显色反应过程中，主要是锌离子与锌显色剂发生络合反应形成络离子，进而形成絮状络合物。络离子一般比较稳定，但在水溶液中也存在着电离平衡，也就是说当显色条件发生变化时，既有可能形成络离子，也有可能发生络离子的分解，从而影响络合反应的程度。显色条件包括显色剂用量、pH值、反应温度、显色时间、待测溶液的盐度以及浊度等。重点研究待测溶液的盐度对锌离子浓度测量值的影响，并通过实验给出影响规律以及校正模型。     

低强度超声场中羟自由基分光光度法检测研究

研究了不同pH(7～11)、不同乙醇体积分数(45%～85%)的孔雀石绿乙醇溶液的紫外-可见光吸收特性,通过最大吸收波长为620nm处的吸光度与浓度关系工作标准曲线,在低强度超声场中,分别检测超声条件和非超声条件下孔雀石绿溶液吸光度变化,两者的差值就是超声场产生的羟自由基导致的孔雀石绿吸光度变化,从而间接测定了超声场产生的羟自由基浓度。确定了4个超声条件产生的羟自由基浓度,最小检测限达到8.4×10-6 mmol.L-1,相对标准偏差为9.4×10-5～3.7×10-4 mmol.L-1,显示出较高精确度和较好重复性,特别适于中性、碱性乙醇溶液体系中羟自由基极低浓度情况下的快速检测。由于孔雀石绿对热敏感,因此该法可以比测量温度,更好地反映超声场热效应的作用。     

分光光度法测定注射用复方维生素(3)草酸含量

采用分光光度法测定注射用复方维生素(3)中微量草酸的方法.在氯化钾-盐酸缓冲液下,Fe3+和草酸的络合物能使Fe3+与磺基水杨酸的紫色络合物颜色变浅,测定显色反应后溶液的吸光度,试验中优化了显色反应时间、显色剂用量.结果显示,显色溶液最大吸收波长为503nm,草酸在0.006-0.036mg/mL浓度范围内,其吸光度与浓度呈良好线性关系,y=-17.552x+1.0283,r=0.9991.样品加样回收率为97.6％.本方法能准确检查注射用复方维生素(3)中微量草酸的含量.     

紫外分光光度法测定普卢利沙星胶囊的含量

建立紫外分光光度法测定普卢利沙星胶囊含量的方法。采用紫外分光光度法,以0.1mol.L-1盐酸溶液为溶剂,测定波长为274nm。在1.2—12μg.mL-1浓度范围内,吸光度与相应的浓度呈良好的线性关系（r=0.9999）;重复性实验中,吸光度测定平均值为0.5825（n=6）,相对标准偏差为0.1%;回收率实验中,平均回收率为99.6%（n=9）,相对标准偏差为0.2%。本方法结果稳定,重复性好,为普卢利沙星胶囊提供了一个简单方便的含量测定方法。     

镜片颜色深浅对立体视觉影响的光谱学研究

利用紫外-可见吸收光谱技术,对红、黄、蓝三种色系中颜色深浅不同且焦度为零的眼镜片,进行了紫外-可见光吸光度的研究;并从医学角度研究比较了人配戴同一色系颜色深浅不同的镜片对立体视觉的影响。研究发现:黄、蓝两色系的镜片,深色样品和浅色样品在紫外光区吸光度基本一致;在可见光区550nm处,深色样品的吸光度大于浅色样品的吸光度。红色系的镜片,在紫外光区浅色样品吸光度高于深色样品吸光度;在可见光区550nm处,浅色样品吸光度仍然高于深色样品的吸光度。人配戴黄、蓝两色系的浅色镜片,其立体视觉优于配戴此两色系中的深色镜片;人配戴红色系的深色镜片,其立体视觉优于配戴此色系的浅色镜片。结果表明:眼镜片颜色深浅对立体视觉的影响,主要取决于人类眼睛最敏感光波550nm处镜片的吸光度,吸光度愈高,镜片对立体视觉的影响愈大。     

贵州民族药秋海棠药材中多糖的含量测定

采用硫酸-苯酚法,以无水葡萄糖为对照品,于485nm处测定吸光度,测定秋海棠药材中多糖的含量。在3.01—10.54μg.mL-1范围内吸光度与葡萄糖溶液浓度的线性关系良好（r=0.9997）,平均回收率为98.06%,RSD为0.50%。该方法简便快速、准确可行,为秋海棠药材的质量控制提供了实验依据。     

Ar+激光和532 nm激光及其线偏振激光辐照光学模型下人正常小肠组织光学特性

采用双积分球系统和光辐射测量技术的基本原理以及运用生物组织的光学模型 ,研究了 4 76 5 ,4 88,4 96 5 ,5 14 5 ,5 32nm激光及其线偏振激光辐照人正常小肠组织的光学特性。结果表明 :组织对激光及线偏振激光的衰减系数和散射系数随着波长的减小而增大 ,而 5 14 5～ 5 32nm波长之间 ,线偏振光与非线偏振光入射则开始有明显差异。吸收系数是随着波长的减小而缓慢地增大 ,而 5 14 5～ 5 32nm波长之间吸收系数的改变则明显变小 ,与是否线偏振光入射无明显差异。平均散射余弦也是随着波长的减小而增大 ,光学穿透深度则是随着波长的增大而增大 ,折射率在这五个波长范围内的值在 (1 38～ 1 4 8)之间。Kubel ka Munk二流模型下组织对同一波长的激光及其线偏振激光的吸收系数、散射系数、总衰减系数、有效衰减系数没有显著性差异 (P >0 0 5 )。组织对不同波长的激光或其线偏振激光的吸收系数、散射系数、总衰减系数、有效衰减系数是有差异的。而在 5 14 5～ 5 32nm波长之间其光学特性参数有较为明显的差异。     

LD相对于铯原子超精细跃迁线的偏频锁定

Holographic storage properties of iron-doped and cerium/iron-doped LiNbO3 with different doping concentrations and treatment conditions have been measured for different recording wavelengths. The results show that at recording wavelengths of 532 nm and 633 nm the holographic storage properties of Ce:Fe:LiNbO3 are generally better than those of Fe:LiNbO3.     

The Comparison of the Holographic Storage Properties of Fe:LiNbO3 and Fe:Ce:LiNbO3 Crystals

Holographic storage properties of iron-doped and cerium/iron-doped LiNbO3 with different doping concentrations and treatment conditions have been measured for different recording wavelengths. The results show that at recording wavelengths of 532 nm and 633 nm the holographic storage properties of Ce:Fe:LiNbO3 are generally better than those of Fe:LiNbO3.     

准分子激光功率标准探测器的研制

采用高热导率碳化硅陶瓷作为吸收体材料,基于厚膜技术制作电热单元,研制了10 mW～1 W电校准准分子激光功率标准器,基于电替代法实现激光功率量值复现,量值复现不确定度达到0.26%（k=1）。在脉冲激光条件下对SiC陶瓷和几种常用的面吸收体材料进行了激光损伤测试,结果显示高热导率SiC陶瓷具有较高的抗损伤性能,设计的锥形结构吸收体在248 nm准分子激光条件下能量损伤阈值为2.2 J/cm2。在多波长下基于积分球系统测量了腔体吸收率,介绍了248 nm准分子激光条件下吸收率测量方法,设计的腔体在几种波长下吸收率大于0.99。基于电校准法实验测量了标准器的光电等效性,灵敏度光电不等效修正因子为1.002 6。     

基于自加权交替三线性分解的荧光检测油类污染物

设计水中油类污染物检测仪,采用脉冲氙灯作为光源,选择阶跃型多模纯石英光纤对激发光和发射光进行传输。采用非对称Czemy-Turner光路的高精度光栅单色器。应用该装置测定柴油、汽油和煤油的荧光光谱,0#柴油、97#汽油和煤油的最佳激发波长/发射波长分别为：290/330,270/300和280/330 nm。检出限：柴油(0.025 mg·L-1)、汽油(0.042 mg·L-1)和煤油(0.054 mg·L-1)。相对误差：柴油(2.55%),汽油(2.06%)和煤油(1.71%),实验表明所设计的检测仪具有较高的测量精度。配置不同浓度的柴油、汽油和煤油的混合溶液,测量其三维荧光光谱,采用自加权交替三线性分解算法对光谱数据进行分解,预测浓度及回收率均表明自加权交替三线性分解算法对混合油类物质有较高的分辨能力。     

Enhanced ultraviolet to near-infrared absorption by two-tier structured silicon formed by simple chemical etching

Two-tier structured silicon with micron/nanometre scale features is fabricated by simple wet chemical etching. The structured silicon sample exhibits dramatically enhanced absorption from ultraviolet to near-infrared wavelength (250–2500?nm). Absorption is enhanced to near unity at wavelengths shorter than 1100?nm caused by the extremely suppressed reflection from the two-tier structured surface. Within the wavelength range from 1100 to 2500?nm, the sample exhibits a strong absorbance of 69.6% at 1100?nm and an average of 30% at longer wavelengths. By analyzing XPS spectra from the surface of the two-tier structured sample, we attribute this near-infrared absorption to band structure and morphological changes presented in the textured layer.     

5个不同波长的激光及其线偏振激光辐照人正常膀胱组织光学特性

采用双积分球系统和光辐射测量技术的基本原理以及运用生物组织的光学模型,研究了476.5, 488, 496.5, 514.5和532 nm激光及其线偏振激光辐照人正常膀胱组织的光学特性。结果表明：组织对激光及线偏振激光的总衰减系数和散射系数均随着波长的增大而减小,而且线偏振激光与非线偏振激光入射是有明显的差异。吸收系数是随着波长的增大而缓慢地减小,但有一些起伏,而与是否线偏振光入射无明显差异。平均散射余弦也是随着波长的增大而减小,而且线偏振激光与非线偏振激光入射是有明显的差异。光学穿透深度则是随着波长的增大而增大,而有一些起伏。折射率在这5个波长范围内的值在(1.37～1.44)之间。Kubelka-Munk二流模型下组织对同一波长的激光及其线偏振激光的吸收系数、散射系数、总衰减系数和有效衰减系数没有显著性差异(P＞0.05)。组织对不同波长的激光或其线偏振激光的吸收系数、散射系数、总衰减系数和有效衰减系数则有些是有明显的差异。     

Absorption Coefficient Measurements of Strongly Scattering Media Using Time-Resolved Transmittance of a Short Pulse in Near-Infrared (NIR) Wavelength Range

Absorption coefficient measurements of strongly scattering and weakly absorbing media have been performed using time resolved transmittance of a 100 fs pulse through a 30 mm slab containing latex spheres suspended in water and absorbing ink solutions. The scattering and absorption coefficients were selected so that the optical properties of the media were similar to those of biological tissues. Measured curves of time-resolved transmittance of the pulse through the media were used to estimate the optical properties of the media. The experiment was made at two different wavelengths, 784 nm and 810 nm. Estimated absorption coefficients were in good agreement with those measured in a nonscattering case by a spectrophotometer.Presented at the 7th International Workshop on Multiple Scattering Lidar/Light Experiments (MUSCLE7), July 21-23 1994, Chiba, Japan.     

Laser wavelength dependence of background fluorescence in Raman spectroscopic analysis of synovial fluid from symptomatic joints

Gout is a disease process where the nucleation and growth of crystals in the synovial fluid of joints elicit painful arthritis‐like symptoms. Raman spectroscopy is evolving as a potential diagnostic tool in identifying such crystals; however, attainment of sufficient Raman signal while overcoming the background fluorescence remains as a major challenge. The current study focused on assessing whether excitation in 532–700 nm range will provide greater signal intensity than the standard 785 nm while not being impeded by background fluorescence. We characterized the fluorescence spectra, absorption spectra and Raman spectra of synovial fluid from patients who presented ‘gout‐like symptoms’ (symptomatic) and controls (asymptomatic). A digestion and filtration method was developed to isolate crystals from synovial fluid while reducing the organic burden. Spectral profile and photobleaching dynamics during Raman spectroscopy were observed under an excitation wavelength range spanning 532 to 785 nm. Absorbance and fluorescence profiles indicated the digestion and filtration worked effectively to extract crystals from symptomatic synovial fluid without introducing additional fluorescence. Raman spectral analyses at 532 nm, 660 nm, 690 nm and 785 nm indicated that both asymptomatic and symptomatic samples had significant levels of fluorescence at excitation wavelengths below 700 nm, which either hindered the collection of Raman signal or necessitated prolonged durations of photobleaching. Raman‐based diagnostics were more feasible at the longest excitation wavelength of 785 nm without employing photobleaching. This study further demonstrated that a near‐infrared (NIR) OEM‐based lower‐cost Raman system at 785 nm excitation has sufficient sensitivity to identify crystals isolated from the synovial fluid. In conclusion, while lower excitation wavelengths provide greater signal, the fluorescence necessitates NIR wavelengths for Raman analysis of crystal species observed in synovial aspirates. Copyright © 2013 John Wiley & Sons, Ltd.     

Cavity-ring-down spectroscopic studies of NO2 in the region around 613 nm

Catalytic degradation and diffusion processes of NO₂ were followed by cavity-ring-down spectroscopy (CRDS) at 612.9 nm. The suitability of this absorption method for quasi-continuous, direct quantitative measurements over extended periods of time is demonstrated. The high sensitivity of the method is reflected by the fact that NO₂ concentrations as low as 200 ppb were detected at wavelengths at which the absorption of NO₂ is 12-fold lower than at the absorption maximum at 413 nm. Absorption coefficients of less than 1×10^-7 cm^-1 were measured. Received: 25 February 2000 / Revised version: 4 August 2000 / Published online: 5 October 2000