垃圾渗滤液中溶解性有机物组分的三维荧光特性

运用三维荧光光谱技术研究了垃圾渗滤液中六种DOM组分的荧光特性。结果表明:类富里酸、类色氨酸和腐殖酸类物质是垃圾渗滤液DOM的主要组成,其中大量紫外区类富里酸物质的存在,是导致其可生化性差的主要原因。HOA含有较多紫外区类富里酸和较少可见区类富里酸,HIA正好相反;HIN组分主要包括紫外区和可见区类富里酸;HOB、HIB和HIN三种组分在各区域荧光信号都较强,包括HON组分在内,这四种组分荧光峰位置主要集中在类腐殖酸、紫外区类富里酸及可见区类富里酸三个区域;但不同组分的荧光强度差别较大,HOB和HIB在紫外区类富里酸有较强荧光强度,HIN在紫外区类富里酸、可见区类富里酸区域均有较强荧光强度;与这三者相比,HON在各位置的荧光信号中等;而HOA和HIA的荧光强度相对较弱,说明有机酸类物质的荧光特性较差。     

獐子岛附近海域溶解有机物的荧光特征

利用平行因子分析(PARAFAC)模型对三维荧光光谱(EEMs)进行解析,研究了獐子岛附近海域不同季节荧光溶解有机物(DOM)荧光的组成特点及分布变化。调查水域在不同季节的DOM荧光组成基本一致,包含类腐殖质荧光组分C1(265/440nm),C2(410～450/520～550nm)和类蛋白荧光组分C3(230,280/330nm),且三者有很好的相关性,表明它们有着相同的来源或彼此间存在某种关系。各组分在不同季节不同水层的分布有在獐子岛周围海域荧光强度相对较大的共同点。通过对各组分与叶绿素a和盐度变化的关系研究发现,调查海区OM受现场浮游植物和人类生产活动的共同作用。分析结果有效的证明了EEMs与PARAFAC相结合对DOM荧光进行分析鉴别的可行性。     

pH值对雨水中溶解有机物荧光光谱特征的影响

利用三维荧光光谱研究了pH值改变对雨水中溶解有机物(DOM)荧光组分及荧光指数的影响。2009年夏季在厦门湾采集了一个具有正常pH值的雨水样品,利用平行因子分析(PARAFAC)识别出雨水DOM具有6个荧光组分,包括4个类腐殖质(C1,C3,C4和C5)、1个类蛋白质(C2)以及1个未知组分(C6)。当pH值从初始的5.7增加到10.7,C1,C3和C5的荧光强度均呈增加趋势,而C4及C6的荧光强度则不断减小,导致类腐殖质组分所占比例不断增大;而当pH值减小、酸性增强时则呈相反的变化趋势,且未知组分C6所占比例占优势。类蛋白质组分C2的荧光强度及所占比例随pH变化基本保持不变。荧光指数(FI)、腐殖化指数(HIX)和自生源指标(BIX)也都受到pH值变化的影响。本研究表明,在雨水DOM光谱研究中,应同时测定、报道样品的pH值以便评估雨水荧光特性的"pH效应"。     

太湖典型湖区水体溶解有机质的光谱学特征

应用荧光光谱、紫外光谱及多种紫外参数等光谱学手段对太湖水体溶解有机质(DOM)进行分析测定,探讨太湖典型湖区水体中DOM的来源及其影响因素。结果表明:不同湖区水体DOM组成特性呈现出一定的区域特征,位于入湖河流的T1点和T2点所代表的竺山湾湖区,结构复杂的大分子物质和腐殖质类物质含量较多,这些区域受多重来源包括生物来源、陆源及生产生活污水的影响较大;以T3为代表的梅梁湾湖区、T4为代表的贡湖湾湖区和T5所处的湖心区其DOM复杂化程度相对较低;而T6点代表的东太湖湖区,因受外界环境的影响较小,以结构简单的类蛋白物质含量居多。     

用特征光谱荧光标记技术分析水中溶解有机物特性

讨论了一种自然水体中有机物的快速诊断分析方法。介绍了总荧光光谱(TLS)和特征光谱荧光标记(SFS)技术;以激光诱导荧光(LIF)方法测量了水体的总荧光光谱,利用特征光谱荧光标记技术对水体中溶解有机物(DOM)及叶绿素a(Chla)进行了分析,并给出了不同浓度腐殖酸的归一化荧光强度与浓度的关系曲线．结果表明,利用特征光谱荧光标记技术对水体总荧光光谱的分析,可以进行水体污染物的快速、实时和在线监测。     

水库型河流溶解有机物三维荧光光谱的平行因子分析

利用三维荧光光谱(EEMs)并结合平行因子分析(PARAFAC)模型,研究了2008年6月水库型河流闽江中溶解有机物(DOM)的荧光组分特征及其分布变化,以探讨河流DOM的来源、动力学过程及主要控制因素。闽江DOM包括类腐殖质组分C1(<250,325/424nm)、C2(270,395/482nm)与类蛋白质组分C3(<250,280/358nm)等三种荧光组分,其中类腐殖质组分占绝对优势。利用荧光组分可对上游三条支流之间的混合进行灵敏的指纹示踪。闽江干流DOM荧光组分的含量基本一致,反映了大型水库修建对闽江有机碳循环尚未产生显著影响。利用相关和主成分分析揭示出闽江类腐殖质组分主要来源于流域土壤的冲刷,它与吸收系数a(355)之间的关系密切;而类蛋白质组分主要在水环境中产生,可用于示踪水体中总溶解氮(TDN)的变化。利用荧光组分的多元线性回归可有效地对溶解有机碳(DOC)的含量进行示踪,表明EEMs-PARAFAC是研究河流DOM动力学过程的重要手段。     

水母代谢过程中释放的溶解有机质的光谱特征

研究了实验室培养的小型水母弗洲指突水母(Blackfordia virginica)代谢过程中所释放的溶解有机物(DOM)及其吸收和荧光光谱特征的变化。与对照组海水相比,充分摄食后的水母在24h的代谢过程中向水体释放大量的溶解有机碳和总溶解态氮,有色溶解有机物的吸收系数a280也有显著增加。光谱斜率比值(SR)的增大和腐殖化指数(HIX)的降低,表明水母代谢产生的主要是腐殖化程度较弱的低分子量DOM。利用平行因子分析(PARAFAC)模型对三维荧光光谱进行解谱,识别出3个类腐殖质(C1-C3)和1个类蛋白质(C4)组分。发射波长在400nm以下的"海源"类腐殖质组分C2(<250,295/386nm)及类蛋白质组分C4(275/334nm)在代谢过程中有明显增加,表明它们是水母代谢释放的主要荧光物质;而发射波长在400nm以上的组分则变化不大。据此可将发射波长小于400nm与大于400nm的荧光组分强度和之间的比值,构建为DOM的浮游动物来源指标(ZIX),用于识别和示踪水环境中浮游动物代谢活动释放和产生的DOM。     

Efficiency of fluorescence excitation in chlorophyll <Emphasis Type=Italic>a</Emphasis> by the second and third harmonics of emission from an Nd:YAG laser

We have studied the efficiency of fluorescence excitation in chlorophyll a by the second harmonic (532 nm) and the third harmonic (355 nm) of an Nd:YAG laser for sea water samples with phytoplankton taken during different algal blooms and for extracts of higher plants diluted with sea water. We have shown that when using the second harmonic, the efficiency of fluorescence excitation in chlorophyll a is more than twice as high as for excitation by the third harmonic. We discuss the advisability of using the second or third harmonics of the emission from an Nd:YAG laser when studying the biooptical parameters of sea water. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 2, pp. 224–227, March–April, 2008.     

机载激光诱导荧光遥感系统相关参数的讨论

以文献[1]所设计的机载激光诱导荧光遥感成像系统为例,简要地分析了该遥感系统的荧光参数、信噪比、飞机飞行参数与系统性能的关系。探测器接收到的荧光强度和信噪比除了与激光器发射的功率、被激发物质的荧光量子效率、密度、浓度和探测器的量子效率等成正比外,还受遥感系统的仪器结构、探测器的灵敏度、荧光寿命、阳光的反射,以及大气散射等因素的影响。给出了遥感系统的空间分辨率与飞机飞行高度和速度、激光扫描频率和脉冲发射频率之间的关系。分析结果对实际研制机载激光荧光遥感系统有重要的参考价值。     

溶解有机物三维荧光光谱技术在赤潮藻识别中的应用

将赤潮藻生长过程中产生的荧光溶解有机物(fluorescent dissolved organic matter,FDOM)的三维荧光光谱与主成分分析相结合,尝试建立了我国沿海10种常见赤潮藻的识别测定技术.用主成分分析提取三维荧光光谱第一主成分载荷谱作为识别特征谱,建立了浮游植物荧光特征谱库,在此基础上利用Bayes...     

激光诱导荧光水体污染遥测数据定量分析方法

在紫外光的激发下,污染水体中的溶解有机物(DOM)会产生特定的荧光光谱,因此利用激光诱导荧光(LIF)可对水体中的溶解有机物的含量进行定量分析,从而可估计出水体富营养化的程度。提出了一种用于对水质遥测数据进行定量分析的方法,这是一种基于遗传算法(GA)的光谱分离算法。首先确定拉曼散射信号和溶解有机物的荧光在404nm波段的信号强度,然后再利用拉曼散射信号对DOM荧光光谱进行归一化处理。根据浓度校准曲线可得到水体中的溶解有机物的浓度。     

Dissolved organic matter inhibition of sonochemical degradation of aqueous polycyclic aromatic hydrocarbons

Sonochemical degradation of aqueous polycyclic aromatic hydrocarbons (PAHs) was found to be rapid in the absence of other dissolved compounds (k = 0.006-0.015 s-1). In the presence of 20 mg Cl-1 fulvic acid, first-order PAH degradation rate constants decreased from 2.3- to 3.7-fold. Similar results were obtained with added benzoic acid, a crude analog for fulvic acid. In natural waters, PAH degradation was almost completely inhibited. Analysis of the kinetic behavior and reaction products indicates that PAHs are most likely degraded through a radical cation mechanism. Hydroxyl radical appeared to play an insignificant role in the degradation. Inhibited degradation was probably the result of either altered cavitation processes or isolation of the PAH away from cavitation sites.     

Influence of the mineral component in biotissues affected by calcinosis on their laser-induced fluorescence spectrum

Laser-induced fluorescence (LIF) spectra of human cardiac-valve tissues affected by calcinosis and of macroscopic calcinosis formations produced from resected cardiac valves with such pathology were investigated by comparison with analogous spectra of bone and myocardial tissue of an animal, LIF was excited by an excimer laser with λ=248 nm. In the spectrum of macroscopic calcinosis formations, luminescence bands of the mineral component were separted from the band of protein tissues when these tissues were subjected to heat treatment at 700°C. The investigations have shown that the LIF spectrum of a calcified tissue contains fluorescence bands of tryptophan and fluorescence bands of the mineral component (hydroxylapatite). A change in the spectrum of tissues with pathological processes can be cause not only by a relative change in the concentration of collagen elastin, but also by the additional fluorescenced of the hydroxylapatite mineral that is absent in a healthy cardiac tissue. It was found that the change in the spectrum characterized by the ratio of the LIF intensity at λ=330 nm to the LIF intensity at λ=450 nm is sufficiently large. This makes it possible to use measurements of the relative intensity of fluorescence at these wavelengths to control the degree of calcination of cardiac tissue. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 6, pp. 846–849, November–December, 1999.     

Fluorescence of nanoparticles of organic matter dissolved in natural water

The fluorescence of nanoparticles of dissolved organic matter under 270-, 310-, and 355-nm excitation is studied for different molecular fractions. The fluorescence quantum yield of the colloidal (molecules of size 5–200 nm) and low-molecular-weight (molecules smaller than 5 nm) fractions are obtained. It is shown that the spectral position of the fluorescence peak depends on both the size of the molecules and the excitation wavelength.     

Energy yield of fluorescence of complex organic compounds upon electron excitation

With use of electron energy loss spectra for vapors of anthracene, perylene, 1,4[di(2,5-phenyloxazolyl)] benzene, and paratherphenyl the energy yields of fluorescence are calculated for electron collision. It is shown that they are considerably smaller than those for optical excitation conditions. Deceased Institute of Molecular and Atomic Physics of the National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 1, pp. 146–148, January–February, 1998.     

The laser-induced fluorescence spectroscopy of TiF in the ultraviolet region

The laser-induced fluorescence (LIF) spectrum of jet-cooled ⁴⁸TiF has been obtained in the wavelength region of 245-270 nm for the first time. Six pairs of vibronic bands were observed and assigned to two new transitions [37.8]⁴Φ-X⁴Φ and ⁴Δ-X⁴Φ. Rotational analysis was carried out for the (ν′ = 0-3 to ν″ = 0) vibrational bands of the [37.8]⁴Φ_3/2-X⁴Φ_3/2 and [37.8]⁴Φ_5/2-X⁴Φ_5/2 subbands, and also, the (ν′, 0) and (ν′+1, 0) vibrational bands of the ⁴Δ_1/2-X⁴Φ_3/2 and ⁴Δ_3/2-X⁴Φ_5/2 subbands. The effective equilibrium molecular constants for the [37.8]⁴Φ_3/2 and [37.8]⁴Φ_3/2 upper states were determined. In addition, lifetime measurements were carried out for all of the observed bands under collision-free conditions. On the basis of the spectroscopic constants and lifetime measurements, the electronic transitions involved in the observed high-lying electronic states are discussed.     

The laser-induced fluorescence spectroscopy of CoF in the ultra violet region

The laser-induced fluorescence (LIF) spectrum of jet-cooled CoF has been obtained in the wavelength region of 260-290 nm for the first time. Seventeen vibronic bands were observed and assigned to three types of transition from the ground state to upper states Ω′ = 3, 4, 5 by rotational analysis. A new vibrational transition with the 0-0 band at 34697.22 cm⁻¹ has been assigned as the [34.7]³Γ₅-X³Φ₄ transition and effective equilibrium molecular constants for the upper state have been determined. In addition, lifetime measurements have been carried out for most of the bands under collision-free conditions. On the basis of the spectroscopic data and lifetime measurements, the electronic structures of these possible high-lying electronic states are discussed.     

Elemental quantitation of natural organic matter by CPMAS 13C NMR spectroscopy

Cross-polarized magic-angle-spinning NMR (CPMAS-NMR) techniques are assumed to be only semi-quantitative in the assessment of carbon distribution in humic substances or natural organic matter, due to a number of interferences such as spinning side bands (SSB) in spectra, paramagnetic species in samples, and low or remote protonation of aromatic carbons. Fast rotor spin rates or direct polarization NMR techniques are normally applied to improve quantitative signal detectability. Variable contact time pulse sequences were used here to obtain CPMAS-NMR spectra of organic compounds of known structure and different humic substances. Integration of spectral areas, previously subtracted of SSB, and relative stoichiometric factors were used for mathematical elaboration to calculate the elemental content in samples. These values did not significantly differ from those obtained by direct determination of elemental content with quantitative elemental analysis. Our results showed that the carbon observed CPMAS-NMR provides a quantitative representation of the whole carbon content in humic substances.     

光谱分辨率对黑土有机质预测模型的影响

高光谱遥感以其高光谱分辨率适于反射光谱特征复杂的地物识别与参数反演,但对于反射光谱特征平滑的地物,高光谱数据可能存在数据冗余问题。本研究对实验室测定的黑土高光谱反射率进行重采样,基于统计分析方法研究了光谱分辨率对黑土有机质预测模型精度的影响,结果表明:黑土有机质含量高,土壤有机质的光谱作用范围宽(445～1 380nm);黑土有机质光谱预测模型精度随光谱分辨率降低,呈现先增后减的趋势,最优模型的光谱分辨率为50nm,低于高光谱遥感波段设置,略高于多光谱传感器波段设置;黑土有机质光谱预测最优模型以倒数对数微分为自变量,模型决定系数R2=0.799,RMSE=0.439,研究成果为土壤有机质遥感反演、光谱速测仪器的研制,以及传感器波段设置提供理论基础与技术支持。     

城镇污水厂尾水人工湿地深度处理过程中DOM三维荧光光谱特征

采用三维荧光光谱(3D-EEM)分析研究了两种基质水平潜流人工湿地在深度处理城镇污水处理厂尾水过程中溶解有机物(DOM)组成特征。结果表明,两种潜流人工湿地对尾水中CODcr和DOC的去除率平均分别达到61.6%和70.1%。相比较而言,陶粒基质湿地对尾水有机物去除效果略优于沸石基质湿地。三维荧光扫描结果显示,湿地进水中表征出类溶解性有机物,即色氨酸类芳香族蛋白质(S)、溶解性微生物代谢产物(T)、可见类富里酸(M)、紫外类富里酸物质(A)。经过人工湿地净化处理后,出水中4个峰的相对荧光强度均有不同程度的降低,其中M峰和T峰的相对荧光强度降低最为明显,平均分别降低了16.4%和11.7%;人工湿地出水中腐殖类物质芳香性较弱,含有的苯环结构有机物较少,这说明潜流人工湿地对尾水中化学性质较为稳定、难以分解、不易被生物利用的类腐殖质有较好的去除效果。M峰和T峰的荧光强度在沿程上逐渐减小,S峰随沿程呈现出先增大后减小的趋势。与沸石湿地相比较,陶粒基质水平潜流人工湿地系统对尾水中DOM的特征峰荧光强度削减更为明显。