基于循环迭代算法的便携式烟气分析仪

为了在紫外光谱烟气分析时从连续的混合气体吸收光谱信号中分离并解算出各气体的浓度,在实验数据的基础上,基于朗伯-比尔定律提出了一种新的循环迭代算法,该算法利用吸光度的叠加性,将数据进行非线性拟合,并利用波长优选和循环迭代,将混合气体的不同成分区分开来.实验结果表明:该方法能够一次同时解算出多种有害气体浓度且精度达±3%,抗干扰能力强,适合工程实际应用.     

维生素C的紫外分光光度法测定研究

应用紫外分光光度法分析技术建立了快速测定维生素C的检测方法.利用样品中维生素C在弱酸条件下将三价铁离子还原为亚铁离子,生成的亚铁离子与邻二氮菲形成橙红色络合物,在最大吸收波长510 nm处生成物吸光值与样品中维生素C质量浓度成比例,结果显示维生素C质量浓度在1～ 30 μg/mL的范围内具有良好的线性关系,相关系数为0.998,相对标准偏差为0.3％～ 1.0％,加标回收率为97.18％～ 102.67％.方法操作简便、可靠,可以用于样品中维生素C的快速测定.     

采油微生物发酵液中各组分对原油量测定的影响

原油量的测定是原油及其产品分析的必要环节,根据芳香烃在255nm具有特征吸收峰,可以通过测定芳香烃量间接表征原油量。本研究采用紫外分光光度法测定原油量,分析采油微生物发酵液中各组分、pH和采油微生物细胞内含物对原油量测定的影响。结果表明,上述因素对该方法测定原油量均没有显著影响,采用紫外分光光度法可以快速、准确地测定微生物采油过程中的原油量。     

油脂中总不饱和脂肪酸的紫外光谱测定

利用紫外光谱测定油脂中不饱和成分,以动物油为对照,主要分析检测了常见的7种植物油．本文确定了紫外谱图分析油脂的检测条件,将原始油配制成0．2％的环己烷溶液;以相似度为指标比较光谱曲线,验证该检测方法具有很好的重现性和特异性;用w检验法确定了共有峰,运用紫外谱图检测化合物共轭结构的原理,对各种油脂中总不饱和脂肪酸进行识别并计算相对含量．紫苏油和核桃油中的不饱和脂肪酸种类最丰富,紫苏油中不饱和双键数4的脂肪酸含量为核桃油的1．5倍,橄榄油中包含的不饱和脂肪酸主要为此种脂肪酸．其次,葵花籽油、玉米油、花生油、杏仁油的总不饱和脂肪酸含量依次递减,动物油中的不饱和脂肪酸未检出．经过碱皂化、甲酯化等方法处理后的样品中,不饱和脂肪酸的紫外吸收光谱特性明显减弱,因此该方法可以简单、快速、准确地测定油脂中的不饱和脂肪酸．     

基于MODIS的春、夏季中国近海气溶胶对于云参数的影响差异研究

通过分析中国近海MODIS数据中气溶胶参数与云参数的相互关系,讨论了该区域气溶胶的间接效应及其对于云的可能影响.结果表明,在中国近海,气溶胶具有明显的间接效应,而且由于气溶胶种类和水汽的季节变化,使得气溶胶的间接作用具有很强的时间变化特征.在夏季,由于人为气溶胶占主导,它作为有效的云凝结核,使得气溶胶光学厚度(AOT)分别与云凝结核数(CCN)有正相关、与云滴有效半径(CER)有负相关性、与云光学厚度(COT)也存在着正相关,气溶胶的间接效应明显;在春季,由于沙尘气溶胶盛行,同时沙尘并不是很好的云凝结核,使得气溶胶光学厚度(AOT)分别与云凝结核数(CCN)的正相关减弱、与云滴有效半径(CER)则由夏季的负相关变为正相关、与云光学厚度(COT)存在弱的负相关,气溶胶的间接效应不明显.     

Energy transfer mechanism of GdPO4: RE3+ (RE = Tb, Tm) under VUV-UV excitation

Polycrystal of GdPO₄:RE³⁺ (RE=Tb, Tm) phosphors were prepared by solid-state method. Vacuum ultraviolet excitation and emission spectrum and the energy transfer mechanism between the host and dopants of Tb³⁺ and Tm³⁺ were investigated respectively. The emission of Gd³⁺ at 313 nm was enhanced by the strong absorption of CTS of Tm³⁺ at 180 nm in GdPO₄: Tm. It has also been concluded that the excitation of Gd³⁺ is transferred to Tb³⁺ and then emission peaks of ⁵D_J→⁷F_J of Tb³⁺ were observed.     

Ultraviolet shielding property of crylic acid resin filled with nano-SiO2

The present status and development trends of nano-composite coatings were briefly introduced. The nano-SiO₂ was dispersed into crylic acid resin by ultrasonic wave and high-energy ball milling, the influence of nano-SiO₂ on shielding property of coatings was investigated. Relation between particle size distribution of original nano-SiO₂ and its dispersal in water and alcohol after treatment were analyzed, respectively. The ultraviolet permeation rate of coatings filled with nano-SiO₂ was detected by ultraviolet spectral photometer. And the particle size distribution of coatings was examined by TEM. The results show that particle size distribution is comparative convergence and smaller one order of magnitude after dispersal treatment. The size of most nano-SiO₂ in coatings is smaller than 100 nm, which indicates that the amount of nano-SiO₂ in the resin is 20% (solid content of resin), the permeation rate of ultraviolet of composite coatings decreases to 20%. The research of its excellent ultraviolet shielding property mechanism indicates minor size and high surface energy of nano-SiO₂ can produce different absorption, reflection and scatter actions to different wavelengths. Foundation item: Project(2001ZB05) supported by Maintenance and Innovation in 2001     

紫外分光光度法测定空气和废气中二氧化氯

以KI作吸收溶剂，采用溶液吸收法采集空气和废气中的二氧化氯，吸收过程中所形成的亚氯酸根在磷酸盐缓冲液介质下，用紫外分光光度法分析。结果表明，以0．5L／min流量采气，采集30min时，采样效率可达98％，最低检出限为0．073mg／m^3，加标回收率为90．0％～97．3％。空气中的氯气对测定结果无明显影响。     

建筑工程紫外线消毒灯应用浅议

对民用建筑工程中常见的紫外线灭菌消毒灯装置 ,从原理、适用性和注意事项等方面作了一定的归纳、分析和总结     

205～350nm紫外高功率可调谐激光的产生

以355nm的主被动锁模YAG激光器输出的皮秒单脉冲做为泵浦源,利用非线性激光晶体BBO的倍频调谐特性,将改进型的离散角补偿的双晶BBO晶体产生的参量光,采用双块BBO晶体把参量光倍频,即可得到调谐范围为205～350nm的紫外高功率激光输出.