两种卤代荧光素与DNA作用荧光特性的研究

对四溴荧光素(TBF)、四氯四溴荧光素(TTF)两种卤代荧光素与DNA作用的荧光特性进行了研究,结果表明：TBF和TTF的最大λ_ex/λ_em为518/540 nm和540/560 nm,DNA的存在会使TBF和TTF的荧光强度发生变化;荧光猝灭实验和偏振实验表明：TBF与DNA的作用方式可能是沟槽键合和嵌插作用,而TTF 嵌插在了DNA碱基对之间;盐效应实验表明：溶液离子强度的大小会影响TBF和TTF与DNA的作用;荧光法测得TBF和TTF与DNA的结合常数为1×106和2×106 L·mol-1,结合位点数为0.62和0.16。     

四溴荧光素与DNA作用的研究

用荧光光谱和磷光光谱法研究了四溴荧光素(TBF)与DNA的相互作用。探讨了盐效应和乙醇在DNA存在和不存在条件下对TBF体系荧光强度的影响,以及不同pH在DNA存在和不存在条件下对体系磷光强度的影响。由荧光猝灭实验,得到无DNA存在下的荧光猝灭常数为719.74 L·mol-1,有DNA存在下的荧光猝灭常数为880.22 L·mol-1。并通过荧光猝灭实验和磷光偏振实验得出了TBF和DNA的可能作用方式。     

胶束体系中荧光素与四溴荧光素间能量转移条件及模型研究

研究了阳离子表面活性剂(CSAA)在水溶液中与阴离子酸性染料四溴荧光素(TBF)的荧光反应,发现当CSAA单体与TBF形成离子缔合物时,TBF的荧光发生猝灭,而CSAA胶束与TBF作用又会产生一个新的、更强的荧光。进而研究了阳离子表面活性剂CTMAB及CPB胶束体系中酸性阴离子荧光染料荧光素与四溴荧光素间的能量转移条件。表明只有在带相反电荷的CSAA形成的胶束中,阴离子染料间的能量转移才可能发生,在2/3临界胶束浓度(CMC)时能量转移效率达到最大。并推测了胶束体系中染料间能量转移模型及染料间能量转移的一般规律。     

黄嘌呤甲基衍生物的发光特性研究

本文对3种黄嘌呤类化合物(咖啡因，茶碱，可可碱)的液氮低温荧光(LTF)、低温磷光(LTP)、室温流体荧光(RTF)及滤纸表面室温磷光(PS-RTP)发光光谱特性进行了对比研究。研究表明，这3种物质的LTF、LTP、PS—RTP及RTF的最大激发波长λex在270—295nm范围内，最大发射波长λem在385—445nm范围内，且它们的λex和λem不论在什么状态下都非常相近。本文也对这3种物质的荧光量子产率、滤纸基质室温磷光(PS—RTP)寿命、偏振等性质进行了比较研究。实验表明：咖啡因、茶碱和可可碱的PS-RTP的寿命均在0．1s数量级，属于长寿命磷光，且PS--RTP为非完全偏振光。     

四溴荧光素丁基罗丹明B染料离子对的吸光性质研究

本文对四溴荧光素、丁基罗丹明B各自的吸光性质以及它们形成的离子缔合物的吸光性质进行了研究.测得四溴荧光素与丁基罗丹明B在pH7时的缔合比为1∶2,其Ksp＝2.16×10-18.缔合物的萃取率为84.2%.为进一步研究四溴荧光素、丁基罗丹明B的萃取光度分析奠定了理论基础.     

四溴荧光素丁基罗丹明B染料离子时的吸光性质研究

本对四溴荧光素、丁基罗丹明Ｂ各自的吸光性质以及它们的形成的离子缔合物的吸光性质进行了研究。测得四溴荧光素与丁基罗丹明Ｂ在ｐＨ７时的缔合比为１：２。其Ｋｓｐ＝２．１６×１０＾－１８。缔合物的萃取率为８３．２％。为进一步研究四溴荧光素、丁基罗丹明Ｂ的萃取光度分析奠定了理论基础。     

四溴荧光黄反射散射光度法测定血清白蛋白

在pH=3.0的B-R缓冲介质中,人血清白蛋白(HSA)与四溴荧光黄(TBF)结合,形成TBF-HSA复合物并被石蜡微晶吸萃,以试剂空白参比,在555nm处产生一灵敏的反射散射吸收峰。HSA的浓度在0.0—1.2mg/L范围内与555nm处的反射散射吸收值呈良好的线性关系。方法对HSA的检出限为0.058mg/L,本方法灵敏,可用于人血清样品中蛋白质的测定。     

新型荧光试剂1-(8-喹啉)-3-(3,5-二溴吡啶)-三氮烯的合成及其分析应用

将具有荧光特性的8-氨基喹啉与吡啶类试剂结合,首次合成了标题化合物1-(8-喹啉)-3-(3,5-二溴吡啶)-三氮烯(QBPyT).其结构经过元素分析、红外光谱、核磁共振谱证实.研究表明,在碱性介质中,该试剂在λex/λem=248nm/496nm处产生强荧光,并且能被Sb(Ⅲ)荧光增强.基于此,建立了QBPyT测定S...     

等色染料离子对浮选光度法研究-四溴荧光素*罗丹明6G体系

本文研究了四溴荧光素（ＴＢＦ）、罗丹明６Ｇ（Ｒ６Ｇ）等色染料离子对浮选光度法测定锗、铂和铁的方法。首先将被测金属离子形成的［ＭｅＬｎ（Ｒ６Ｇ）ｍ］（Ｌ：配位体,ｍ、ｎ为整数）有机溶剂浮选物,用碱解析并反萃于水相。而后加入与罗丹明６Ｇ等色的四溴荧光素溶液继续浮选,将形成的等色染料离子对Ｒ６ＧＴＢＦ浮选物溶解于丙酮。于５３０ｎｍ处测定吸光度值。由于２ｍ个染料同时吸收同一波长的光,而提高了方法灵敏度。测定Ｇｅ、Ｐｔ和Ｆｅ的摩尔吸光系数均在１０５Ｌｍｏｌ－１ｃｍ－１以上     

在溴代十六烷基吡啶存在下5-Br-PADAP分光光度法测定水中微量铁的研究

研究了显色剂2-(5-溴-2-吡啶偶氮)-5-二乙氨基酚(简称为5-Br-PADAP)与铁(Ⅱ)显色反应条件,在pH=6.0的醋酸-醋酸钠缓冲体系中,采用阳离子表面活性剂溴代十六烷基吡啶增溶增敏.铁(Ⅱ)与显色剂形成的配合物组成为Fe(Ⅱ):R=1:2,络合物具有两个吸收峰,分别位于λ1=556nm与λ2=748nm.选择748nm进行测定,其摩尔吸光系数为ξ748=3.3×104L·mol-1·cm-1.铁含量在O-30ug/25mL范围内服从比耳定律.此法用于水样中微量铁的测定,结果准确可靠.     

Study on the spectral behavior of four fluorescent dyes and their interactions with nucleic acid by the luminescence method

The spectral characteristics of four fluorescent dyes: tetrabromofluorescein (TBF), tetrachlorotetrabromofluorescein (TTF), lissamine rhodamine RB 200 (LSR) and methylene violet (MV) were studied by fluorescence and paper substrate room temperature phosphorescence (PS-RTP) methods. The factors affected the luminescence were investigated including pH value, paper substrate and drying conditions, etc. The fluorescence polarizations and PS-RTP lifetimes of these compounds were obtained. The intensity of fluorescence and phosphorescence of TBF and TTF increased in the presence of DNA. Contrarily, that of LSR and MV decreased. The fluorescence quenching and polarization studies indicate that TTF, LSR and MV intercalate into DNA base pairs. In addition, the interaction of TBF with DNA is the comprehensive interaction of two modes: intercalation and groove binding. It was also found that ionic strength could affect the binding of fluorescent dyes and DNA.     

Wavelength-tunable erbium fiber ring laser in single-frequency operation utilizing Fabry-Perot laser with Sagnac cavity

We propose and demonstrate experimentally a stabilized and wavelength-selective erbium-doped fiber ring laser in single-longitudinal-mode operation with Fabry-Perot laser diode (FP-LD) and using a tunable bandpass filter (TBF) inside and outside a Sagnac ring cavity. The side-mode suppression ratios of 21 dB and 36.5 dB and the output power of -3.6 dB m and -8.7 dB m in the wavelengths of 1524.45-1562.35 nm and 1531.07-1562.35 nm with the tuning step of 1.4 nm can be achieved when the TBF outside and inside Sagnac loop, respectively. The output wavelength variation of zero and the output power fluctuation of <0.1 dB are also obtained. Moreover, the transmission efficiency of the ring laser has also been performed experimentally under a 1.25, 2.5 and 10 Gb/s external modulation, respectively.     

等色染料离子对浮选光度法测定铂

提出了等色染料离子对浮选光度法、向罗丹明６Ｇ（Ｒ６Ｇ）和Ｐｔ（ＳｎＣｌ３）５＾３－的异丙醚浮选物Ｐｔ（ＳｎＣｌ３（５（Ｒ６Ｇ）３中，加入ＰＨ＝５．５的醋酸－醋酸铵缓冲溶液，使Ｒ６Ｇ离子进入水相，并向其中加入与Ｒ６Ｇ颜色相同的四溴荧光素（ＴＢＦ）〉形成等色染料等离子对Ｒ６Ｇ，ＴＢＦ，再被甲茉浮选，将浮选物溶于丙酮，于５３０ｎｍ处进行光度测定，由于６个染料分子（Ｐｔ：Ｒ６Ｇ：ＴＢＦ）＝（１：３：３）ｅ     

An experimental investigation of the gain spectrum of erbium-doped fiber amplifiers under various system configurations

The paper presents an experimental investigation of the gain spectrum of an erbium-doped fiber amplifier (EDFA) considering different system configurations, which include single-pass, double-pass, and double-pass with tunable band-pass filter (TBF). The role of TBF is to suppress the undesired amplified spontaneous emission (ASE). Both co- and counter-pumping schemes are considered with a 1480 nm laser diode as the pump and a suitable tunable laser source as the signal source. The results indicate that the signal achieves an average of 14 dB higher gain in the case of double-pass amplification with the implementation of a TBF. However, the pumping scheme hardly becomes of much importance in influencing the gain characteristics.     

双荧光剂荧光光度法研究与应用—溴荧光素.丁基罗丹明B体系

向离子缔合物ＧａＣｌ４ＢＲＢ（ＢＲＢ是丁基罗丹明Ｂ）的甲苯萃取液中,加入ＰＨ＝８．７的ＮａＯＨ－ＫＨ２ＰＯ４缓冲溶液,离子缔合物解析后ＢＲＢ进入水相。向其中加入与ＢＲＢ颜色相近的四溴荧光素,形成的ＢＲＢ２．ＴＢＦ再被甲苯萃取,萃取液中加入正丁醇。因萃取液中ＢＲＢ２．ＢＦ的双荧光剂协同作用,提高了测定镓的灵敏度。     

β-环糊精-苯甲酰二茂铁缩氨基硫脲包合物特征及微环境效应研究

用饱和水溶液法制备了β-环糊精(β-CD)-苯甲酰二茂铁缩氨基硫脲(TBF)的超分子包合物。等摩尔连续变化法证明两者形成了摩尔比为2∶3(TBF∶β-CD)的包合物,通过测定的相应紫外光谱数据求得包合常数K为5.04×1013(L4·(mol)-4)。UV, FTIR, X射线粉末衍射进一步研究其包结特性。同时, 从微环境的角度研究了不同溶剂对β-CD-TBF和TBF的UV光谱的影响以及在水溶液体系中pH值的变化对TBF和包合物的影响特征。结果表明溶液中不同微环境对客体及超分子包合物的电子光谱有着显著而不同的影响。     

Fast photorefractive response in B(12)SiO(20) in the near infrared

The polarization self-modulation effect was applied for effective measurement of the characteristic response time of nominally pure Bi(12)SiO(20) (BSO) at wavelengths of 810 and 980 nm. Owing to oxygen deficiency in the crystal lattice, the BSO crystals showed unusual photorefractive sensitivity and remarkable operation speed in the near-infrared spectral region. A response time of 130 ms was measured at 810 nm, and a response time of 540 ms was measured at 980 nm, with incident intensities of 110 and 200mW/cm(2), respectively. To our knowledge, this is the first experimental evidence of a subsecond response in the infrared for a nonsemiconductor photorefractive material.