抗生素效价测定仪校准用光谱中性滤光片的研制

根据浊度法抗生素效价测定仪吸光度的有效测量范围和液体培养基培养过程中吸光度逐渐降低的特点,选用中性灰色玻璃研制了吸光度标称值分别为0.3,0.5,0.7,1.0的光谱中性滤光片组标准物质。用紫外可见近红外分光光度计对研制的标准物质的均匀性、正反面和稳定性进行测试,吸光度均匀性最大值为0.002 0,吸光度正反面最大差值为0.000 4,吸光度稳定性最大值为0.002 5,符合二级标准物质要求,经评定标准物质吸光度的相对扩展不确定度为1%(k=2)。将该标准物质的定值结果与上一级计量标准中国计量科学研究院的校准结果进行比对验证,结果表明研制的标准物质定值准确,可用于抗生素效价测定仪吸光度准确性和溯源性校准。     

重铬酸铵与明胶光化学反应的光声光谱研究

重铬酸铵与明胶光化学反应的光声光谱研究陈钢进，杜浩，蔡铁权，方健文（浙江师范大学化学系金华３２１００４）（浙江师范大学物理系金华）关键词重铬酸盐明胶，光化学反应，光声光谱重铬酸盐明胶（ＤＣＧ）是全息照相的重要材料，全息图的形成过程是六价铬在光的激发下...     

色谱中的光声光谱检测

光声光谱是本世纪七十年代初期重新兴起的高灵敏度光谱分析新技术。它适用于透明、不透明,甚至强散射样品在紫外,可见,红外光区的光热性质研究,已在物理、化学、工程材料、生物、医学等领域得到广泛的应用。 光声光谱(简称PAS)是一种光热吸收光谱,当用一束调制后的(或脉冲的)单色光照射样品时,样品吸收以后,以无辐射弛豫方式将吸收的光能部分或全部地转换成热,样品受热体积膨胀,产生以光源为中心向外扩展的压力波,用置于其中的声传感器便可接收到光声信号。用波长扫描方法得到样品的光声图谱可做定性分析。根据光声信号大小与物质吸光度成正比的关系进行定量分     

激光光热折射光谱法测量毛细管内液体样品的微弱吸收

本工作采用毛细园柱管为样品池，证实在激光束通过毛细管不发生衍射的情况下，可采用激光光热折射光谱进行“在线”检测。我们还提出了一种通过监测第二针孔光栏产生的菲涅尔衍射条纹，提高检测灵敏度的新方法。检测了内径为３００μｍ毛细管内１．８×１０＾－＾１＾６ｍｏｌ的结晶紫，相应的最小吸光度为３×１０＾－＾７。     

硅青铜光谱标准样品研制

经化学成分设计、原料精选、熔炼加工、均匀性检验等步骤,研制了硅青铜光谱标准样品.该硅青铜光谱标准样品以高纯铜为主原料,按杂质元素的性质,在选定的条件下分批加入Si、Ni、Zn等15种杂质元素制备而成.杂质元素的定值区间分别为:Zn 0.112％～4.29％,Pb 0.030％～0.264％,Sn 0.055％～0.61...     

漫反射傅里叶变换红外光谱法测定制剂中左氧氟沙星

采用新型的制样方法,利用漫反射傅里叶变换红外光谱(DRIFTS)法测定了左氧氟沙星制剂中左氧氟沙星的含量。选择1620 cm-1处的酮羰基伸缩振动吸收峰作为定量分析峰,以1580~1655 cm-1范围内的峰面积评估吸光度,吸光度与左氧氟沙星质量分数在0.20%~1.20%范围内呈良好的线性关系,相关系数为0.984,相对标准偏差(RSD)≤5.6%。新型制样方法可使样品与KBr基质混合更均匀,有效消除镜面反射光及排除辅料中不可溶淀粉对分析测定的干扰,提高分析结果的精密度和准确度;以含可溶性淀粉的左氧氟沙星标准样品绘制标准工作曲线可以消除少量可溶性淀粉对分析测定的干扰。DRIFTS法测定了3种市售制剂中左氧氟沙星含量,结果与紫外分光光度(UV)法基本一致。     

共振光散射光谱的校正

以罗丹明6G在pH7.40时的共振光散射光谱（RLS）为例,引进仪器特性因子和分子吸收因子讨论荧光分光光度计的检测灵敏度和体系分子吸收对RLS光谱的影响,提出光谱校正方程。在吸收体系中,吸收带附近的散射光强度降低,并导致散射光谱发生畸变。通过光谱校正,除消除了不同仪器因光源和检测系统的差异对RLS光谱特性影响外,有效地消除了分子吸收的影响,提高了测定灵敏度。     

人工神经网络用于近红外光谱预测汽油辛烷值

本文对BP人工神经网络(ANN)方法在汽油的辛烷值与其近红外光谱光谱吸光度的关系之间进行关联预报方面进行了研究。采用35个汽油实际样本数据,建立了利用汽油的近红外光谱光谱吸光度预测汽油辛烷值的BP人工神经网络模型。对所有辛烷值的计算结果与实测值进行了比较,得到的预测值与实测值计算误差小于1.55%。     

基于近红外光谱技术与优化光谱预处理的陈皮产地鉴别研究

采集不同产地陈皮内侧和外侧的近红外光谱,采用不同光谱预处理方法进行预处理,筛选得到最佳光谱预处理方法,结合主成分分析法建立了陈皮产地的鉴别模型.实验发现,陈皮原始光谱中存在明显的基线漂移与背景干扰.使用单一光谱预处理可在一定程度上消除干扰的影响.经标准正态变量变换、多元散射校正、一阶导数、二阶导数与连续小波变换预处理后...     

5A66铝合金光谱分析标准样品的制备和定值

阐述5A66铝合金光谱分析标准样品的制备工艺，数据处理及定值结果，在制备过程中，采用自制专用中间合金，分步调整化学成分等先进工艺技术，保证了制备的标准样品成分均匀，采用极差法进行均匀性检测，多家协同定值，定值准确。     

PREPARATION OF HIGH-TEMPERATURE VULCANIZED SILICONE RUBBER OF EXCELLENT MECHANICAL AND OPTICAL PROPERTIES USING HYDROPHOBIC NANO SILICA SOL AS REINFORCEMENT

Hydrophobic nano silica sol(HNSS)was incorporated into polyvinylmethylsiloxane to prepare reinforced high- temperature vulcanized(HTV)silicone rubber.HTV silicone rubber filled with 40 phr HNSS showed excellent mechanical and optical properties:the tensile strength reached 11.7 MPa and the optical transmittance was higher than 90%.Possible reasons for reinforcement and transparency were discussed on the basis of the bound rubber percentage,total crosslink density,and SEM analysis.Our work suggests that H...     

ON THE INTERPRETATION OF ABSORPTION SPECTRA OF LEAVES–II. THE NON-ABSORBED RAY OF THE SIEVE EFFECT and THE MEAN OPTICAL PATHLENGTH IN THE REMAINDER OF THE LEAF

Abstract— The sieve effect and scattering within leaves are analysed by the use of a simple model. By plotting the leaf transmittance (corrected for light not entering the leaf) vs the transmittance of an equivalent amount of homogeneous plastid pigments, an intercept is found where the latter is zero. This minimum transmittance represents the fraction of the leaf area devoted to the ray of the sieve effect which strikes no chloroplasts. It varied between 7% and 0.2% in non-senescent leaves. When this was subtracted from the leaf spectrum, the peak absorbance was greater than that of the homogeneous leaf pigments in all cases. The ratio of the leaf absorbance to that of the homogeneous pigments, at the same wavelength, is the apparent optical pathlength, which increases with decreasing absorbance. By plotting this ratio vs the absorbance of the equivalent homogeneous pigment, an intercept is found where the latter is zero. This intercept is interpreted as an estimate of the true mean scattering pathlength. Leaves with high chlorophyll contents had low pathlengths (mean and SD = 2.30 ± 0.25); with moderate and low contents, the values were higher (2.75 ± 0.28, 3.95 ± 0.77). Another application of the model gave values between 3 and 4 for the true scattering pathlength.     

Preliminary results from a polymer gel dosimeter for absorbed dose imaging in radiotherapy

The reliability for radiotherapy applications of a normoxic-polymer gel dosimeter, analysed by means of optical methods, was studied. The optical transmittance was measured with a spectrophotometer and imaged with a CCD camera. The characteristics of sensitivity, spatial resolution, image stability, linearity of the response and reproducibility were investigated and analysed. Radiation induces a radical polymerisation in the gel matrix and the resulting macromolecules remain fixed in space making therefore possible the absorbed dose imaging.     

分光光度计测铁矿石中钛的测量不确定度评定

紫外-可见分光光度计在化学分析中应用较为广泛。对于借助其进行化学分析测量不确定度的评定，目前较多见于溶液测定。实际应用中，测试样品多为固体，涉及到称样、溶解、稀释、定容等步骤。此文试从随机效应和系统效应的角度考虑，对紫外-可见分光光度计应用ISO4691：1985铁矿石中钛含量的测定——二安替比林甲烷分光光度法对铁矿石中钛的测量过程中的不确定度来源进行了较为全面的分析，并最终给出评定结果。     

Controlling the growth of particle size and size distribution of silica nanoparticles by the thin film structure

Nanostructured silicondioxide thin films were prepared by sol–gel spin coating technique. The SiO₂ films were made using a conventional mixture of tetraethoxysilane (TEOS), deionized water and ethanol with various NH₃/TEOS ratios. The nanostructured silica films were made using a mixture of the SiO₂ sol and regular SiO₂ sol to control the enlargement of the particles inside the films. The structural, morphological and optical characterizations of the as-deposited and annealed films were carried out using X-ray diffraction (XRD), atomic force microscopy, scanning electron microscopy, NKD spectrophotometer and ultraviolet–visible (UV–vis) spectroscopy. The transmittance data of the infrared spectra of the films were recorded using an FT-IR Spectrometer. The XRD studies showed that as-deposited films were amorphous and the formation of the alfa-cristobalite phase of the silica film was investigated at annealing temperature close to 1,100 °C. Optical properties of the transmittance spectra in the s and p-polarization modes were collected. Refractive indices and extinction coefficients were determined with respect to the NH₃/TEOS ratios in the compositions of the films. Optical cut-off wavelength values were investigated from the extrapolation of the absorbance spectra which was estimated from the UV–vis spectroscopy measurements. A red shift in the absorption threshold indicated that the size of silica nanoparticles was increased by an increase in the NH₃/TEOS volume ratio from 1:64 to 1:8.     

沉积电位对电沉积ZnS薄膜的影响

采用电沉积方法,在不同沉积电位条件下,在氧化锡铟(ITO)导电玻璃上沉积制备了ZnS薄膜,利用XRD、SEM和UV-VIS测试技术对在不同沉积电位所制备薄膜的晶相结构、表面微观形貌和光学性能进行了表征.研究结果表明:沉积电位在1.5 V—1.7 V范围内制备的ZnS薄膜呈非晶态,其可见光透过率从60 %降低到20 %,薄膜的光学带隙约为3.97 eV.在沉积电位为2.0 V条件下所沉积薄膜为ZnS结晶相和金属Zn混合相,薄膜透过率显著降低.     

聚醚砜单烯大分子单体的合成与表征及其共聚物的光学特性

本文采用溶液法以单酚（４－氯－４’－羟基二苯砜）为原料合成了不同聚合度的单酚低聚体，得到了控制聚合度的最佳聚合条件；用相转移催化剂法成功地将单酚转化为单烯大分子单体，并用ＩＲ、１Ｈ—ＮＭＲ对其结构进行了表征；测定了双键官能度均在１．９０以上．单烯大分子单体与苯乙烯的共聚研究表明，聚合度为２左右的单烯大单体在苯乙烯中溶解度最大，可达８０％以上；共聚物有优异的光学特性，对折射率的提高比相应的双烯大分子单体有利；在可见及近红外区透光率达８９％以上．     

SiO2 溶胶及其静电自组装薄膜的制备

Silica sols were prepared by hydrolysis of Si（OC2H5）4（TEOS）using HCl,NH3·H2O,HCl/NH3·H2O as catalyzers,and the different granularities of SiO2 sols which catalyzed by HCl first and then NH3·H2O have the same terminal pH value were prepared. The silica colloidal particles were investigated with Transmission Electron Microscope（TEM）. The results showed sol catalyzed by HCl possesses very little particle,catalyzed by NH3·H2O has particle configuration,catalyzed by HCl/NH3·H2O possesses consecutive configuration. Poly（diallyldimethylammonium chloride）（PDDA）and SiO2 nanoparticulate complex thin films were prepared by electrostatic self-assembly multiplayer（ESAM）method. After assembling films,thin films surface conformation was observed with Electron Microscope and their transmittance was tested with 721 Spectrophotometer. The results showed that the silica sol catalyzed with HCl is not good for the fabrication of ESAM films and the silica sol catalyzed with HCl first and then NH3·H2O or by NH3·H2O only are very suitable for ESAM film fabrication. TEM data indicate that the microstructure of PDDA/ SiO2 prepared from silica sol catalyzed with HCl first and then NH3·H2O is consecutive and that the microstructure of PDDA/ SiO2 prepared from silica sol catalyzed by NH3·H2O only is particulate-parking like. The dependence of the transmittance of assembled films on the bilayer number of the films and the anti-scratching properties of the films were investigated. The results show that PDDA/ SiO2 films prepared from silica sol catalyzed by NH3·H2O only possess higher transmittance but lower anti-scratching properties. The effect of granularity of sols on optical performances of the thin films was studied,results showed the less the granularity of sol,the better the optical performances. For the sake of improving the light transmittance of films,we can reduce the granularity of sol,but it may play down its mechanical damage resist intensity.     

ANALYTICAL MODELING FOR THE OPTICAL PROPERTIES OF THE SKIN WITH IN VITRO AND IN VIVO APPLICATIONS

Abstract— Analytical modeling that interrelates the optical properties of multilayered structures is applied to the skin. The mathematical approach is based on relations of diffuse reflectance and transmittance of a multilayered system and the diffuse reflectance and transmittance of each component layer. The formula can also be derived from the Kubelka–Munk theory of radiation transfer. Using both collimated and diffuse incident irradiance, the applicability of the model to human epidermis over the UV and visible region has been verified. The model has been applied to calculate the absorption and scattering coefficients of human epidermis in vitro , and to estimate the epidermal transmittance under simulated in vivo condition.     

Fiber-optic glucose biosensor based on glucose oxidase immobilised in a silica gel matrix

A monolithic silica gel matrix with entrapped glucose oxidase was constructed as a bioactive element in an optical biosensor for glucose determination. Physicochemical and biochemical characterizations of the catalytic matrix were performed, and the intrinsic fluorescence of immobilised glucose oxidase (GOD) was investigated in the UV and visible range by performing steady state and time course measurements. In all cases, the silica gel matrix proved to be a suitable support for optical biosensing owing to its superior optical properties (e.g., high transmittance and reliable fluorescence and GOD absorption spectra after immobilisation). From steady state measurements, calibration curves were obtained as a function of glucose concentration. When time course measurements were performed, the silica gel support displayed a larger linear calibration range and higher sensitivity than other immobilisation systems. In addition, a glucose optical biosensor was developed and characterised using as catalytic element GOD immobilised on a gel disk bound to a bundle of optical fibres.