化学发光法测定枳壳中生物碱含量

在酸性介质中,高锰酸钾可氧化辛弗林产生化学发光,对影响化学发光强度的因素进行了实验和探讨,建立了高锰酸钾化学发光体系测定辛弗林的新方法。在最佳实验条件下,辛弗林的线性范围为4.00×10-7—2.00×10-5mol/L;检出限为6.96×10-8mol/L。该体系已经成功应用于枳壳中生物碱含量的测定,回收率为92.8%。此外,本文还测定了酸性高锰酸钾-辛弗林体系的化学发光光谱和荧光光谱,初步探讨了化学发光反应机理。     

利用飞秒受激拉曼光谱技术研究Pyranine分子激发态质子传递过程

本文利用共振增强的飞秒受激拉曼光谱技术结合瞬态吸收光谱技术研究了光致产酸剂Pyranine发色团分子在水溶液中与醋酸根离子之间的光致激发态质子传递过程.实验中观测到了Pyranine发色团在400—1700 cm~(–1)频率范围内去质子化状态下的激发态拉曼振动光谱.同时在920 cm~(–1)处也观测到了质子化醋酸根离子中激发态碳-碳单键伸缩拉曼振动信号.通过对激发态质子传递中给体和受体的动力学的分析得到了在该条件下的激发态质子传递的速率.     

有机自由基发光体

有机自由基由于存在未配对或弱成键电子,因而具有独特的基态开壳电子结构。这类开壳电子结构的分子体系可展示出特殊的物理性质,如近红外吸收、非线性光学响应、可逆电子氧化还原、磁学性质等,有望成为下一代光电磁信息功能材料。然而,绝大多数自由基在光激发态下以非辐射方式释放能量,从而表现为弱发光或不发光。近年来,以三芳基甲基自由基衍生物为代表的双线态自由基发光体逐渐引起研究者的关注,其红光发射的荧光量子产率可达到90%以上,且成功地应用于有机电致发光器件(OLED)。自由基发光体是在基态和激发态均具备自由基特征的新型分子体系,其分子结构设计与发光性质调控是该领域的关键难题。在已报道的仅有的少数发光自由基的基础上,人们更多地期待获得性能优异、可选择性调色的多种类发光自由基及其作为功能材料的潜在应用。本文总结了发光自由基的分子结构、物理性质和构效关系,以及激发态发光机制与自由基非辐射跃迁抑制机理等,讨论了目前的研究现状和未来的研究挑战。     

2018年5期 电子期刊

研究了不同Mn/Pb量比的Mn掺杂CsPbCl₃（Mn：CsPbCl₃）钙钛矿量子点的发光性质。Mn/Pb的量比增加引起的Mn²⁺发光峰的红移,被认为是来源于高浓度Mn²⁺掺杂下的Mn²⁺-Mn²⁺对。进一步研究了Mn：CsPbCl₃量子点的发光效率与Mn/Pb的量比之间的关系,发现随着量比达到5：1时,其发光效率明显下降。这种发光效率下降是由于Mn掺杂浓度引起的发光猝灭。Mn：CsPbCl₃量子点的变温发光光谱证实,随着温度的升高,Mn离子发光峰蓝移,线宽加宽,但其发光强度明显增加。     

4-四氢喹啉酮的合成及发光性能

对喹吖啶酮结构改造合成了新型结构荧光体4-四氢喹啉酮,对其吸收光谱及荧光光谱进行了研究,发现该化合物的吸收峰及荧光发射峰随溶剂极性的增加而不断红移,表明荧光来源于分子内激发态电荷转移发光.该化合物在固态即显示荧光,表明经结构改造后,消除了喹吖啶酮类的固态荧光猝灭效应.4-四氢喹啉酮结构简单,易于合成和结构修饰.这对于寻找新的主体荧光发射材料具有重大意义.     

Eu,Dy共掺铝硼硅酸盐的长余辉发光玻璃

选择铝硼硅酸盐玻璃体系,高温熔融法制备了Eu,Dy掺杂的铝硼硅酸盐基质透明的玻璃,并对其进行了激发光谱和发射光谱的表征分析。实验结果表明：在空气气氛条件下制备的Eu^3＋,Dy^3＋掺杂的铝硼硅酸盐基质玻璃样品并不具备长余辉发光特性;而经过还原气氛处理后,Eu离子以二价形式存在,样品具有长余辉发光现象。其激发光谱是位于250-450nm的宽带谱,发光光谱峰值位于462nm处。     

铝对过渡金属离子掺杂的二氧化硅溶胶凝胶玻璃发光性质的影响

用溶胶凝胶法制备了过渡金属离子(Ni2+,Mn2+和Cu2+)单掺、铝共掺的二氧化硅玻璃,测量了荧光光谱、吸收光谱和红外光谱,研究了Al3+对过镀金属离子在二氧化硅玻璃中发光性质的影响。研究结果表明,Al3+对过渡金属离子的发光性质有着显著影响:Ni2+,Mn2+和Cu+的发光强度大幅度提高,Mn2+的发光峰峰位改变。     

流动注射化学发光测定血浆中的多巴胺

在酸性介质中,高锰酸钾氧化甲醛产生化学发光信号,当该体系中存在多巴胺时,体系发光信号显著增强,基于这一现象,建立了一种简单快速测定多巴胺的流动注射化学发光新方法.并且对试验条件进行优化.在最优条件下,多巴胺在6.0×10-8-2.0×10-5mol/L范围内与发光强度呈良好的线性关系,检出限是2.0×10-8mol/L.对2.0×10-6mol/L的多巴胺标准溶液平行测定11次,平行测得值的RSD为3.4％.将本法用于血浆中多巴胺的测定,结果令人满意.     

测定双嘧达莫的化学发光新方法

提出了双嘧达莫与高锰酸钾和罗丹明B的化学发光新体系,并发现表面活性剂吐温-80可显著增强该体系的化学发光,据此建立了流动注射化学发光测定双嘧达莫的新方法。该方法选择性好,灵敏度高,线性范围宽,双嘧达莫在5.0×10-8～5.0×10-5g·mL-1范围内与发光信号呈线性关系,检出限1.7×10-8g·mL-1, RSD为1.1%(n=11, c_s=1.0×10-6g·mL-1双嘧达莫浓度)。     

CaSO4掺Eu和Ag,Mn的热释发光谱

用三维发光谱方法,研究了掺Eu和Ag,Mn的CaSO4热释光材料的发光特性。测定了CaSO4：Eu(0．1％,摩尔分数)经1kGy的^60Co的γ射线照射后的热释发光谱,观察到Eu^2 离子的波长为385nm,温度为120,154℃的两个发光峰,Eu^3 离子在波长590,620,700nm处有多个发光峰。测量样品经不同温度热处理后的热释发光谱,发现Eu^2 和Eu^3 离子的发光强度随热处理温度变化规律极不相同,可见,Eu^2 和Eu^3 浓度比可通过热处理来改变,从而得到需要的Eu^2 和Eu^3 相对发光强度。通过CaSO4：Mn(0．5％)和CaSO4：Eu,Mn(0．1％,0．1％)热释发光谱的比较,观察到Mn^2 不仅是发光中心,而且能起能量转移的作用。实验得到的CaSO4：Eu,Mn磷光体有很高的发光效率。实验结果表明Eu^2 取代CaSO4中的Ca^2 ,不需要电荷补偿,有比较稳定和简单的结构,其热释光峰基本符合以一陷阱和一发光中心为前提的一级动力学模型,Ag和Mn的掺入不产生Eu^2 的高温发光峰。当Eu^3 在CaSO4中取代Ca^2 离子时,因其价态不同,则需电荷补偿,可能产生缺陷复合体和局部跃迁发光,它的热释光发光机制不能用一级动力学方程表示,而Ag的掺入起电荷补偿作用,从而改变了Eu^3 发光峰温,而对Eu^2 的发光峰温影响极小。     

Guided-Wave Two-Dimensional Acousto-Optic Scanner Using Proton-Exchanged Lithium Niobate Waveguide

Two-dimensional scanning of a 0.6328 mum guided-light beam has been realized using noncolinear acousto-optic (AO) coplanar Bragg diffraction together with colinear AO guided-mode to substrate radiation-mode conversion in a Z-cut Xpropagation LiNbO3 proton-exchanged (PE) waveguide. The two surface acoustic (SAW) waves utilized are at the center frequencies of 500 and 200 MHz, propagating in the Y and X axes, respectively. Two-dimensional scanning of approximately 720 resolvable light beam spots, namely, 18 40 (horizontal vertical) scanning, has been demonstrated using a light beam of 1.0 mm aperture. The total number of resolvable beam spots can be greatly increased from 720 by simply utilizing SAW transducers of larger bandwidth and a light beam of greater aperture. It should also be possible to significantly increase the diffraction efficiency from 3 % by optimizing the parameters of the PE waveguide and the SAWs.     

Femtosecond Transform-Limited Pulse Generation by Compensating for the Linear Chirp of SPM Spectra in Dispersion Shifted Fibers

A simple technique of pulse compression, based on the linear chirp compensation of self-phase modulation (SPM) spectra in dispersion shifted fibers, is demonstrated. The optimization procedure is carried out, for a short span of a single-mode fiber, using a parabolic law, which describes the behavior of the squared output pulse width versus the pump peak power in the case of Gaussian pulses. The experimental results give a minimum pulse duration of 233 fs, which is in good agreement with the model. Shorter and coherent pulses, down to 90 fs, have been obtained by inserting an interference filter at the optical output.     

Effect ofγ-radiation on the spectral luminescence characteristics of impure cadmium tungstate crystals

Results of a study of the effect of γ-radiation on the spectral luminescence properties of cadmium tungstate crystals doped with silver, bismuth, and molybdenum cations are presented. Spectral characteristics of the nondnnnoped crystals are briefly described. Absorption and photo and X-ray luminescence spectra of the crystals taken before and after exposure to γ-radiation (5.5·10⁴ Gy) are compared. It is found that the spectral characteristics of the crystals doped with silver, bismuth, and molybdenum cations do not change markedly after the exposure. The relation between the type of impurity-induced defects, individual characteristics of the impurity cations, and the character of the effect of γ-radiation on the spectral luminescence properties of impure crystals is analyzed (preliminarily). Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 55–60, January–February, 1997.     

Sorting of bending magnets for the SSRF booster

The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper.     

Theoretical analysis and simulation of conjugate heights for dual-conjugate AO system in lidar

A multi-conjugate adaptive optics （MCAO） can offer a possibility of widening field of view （FOV） characterized by the isoplanatic angle, and the choose of conjugate height becomes a basic problem for MCAO, which influences the size of iosplanatic angle. Considering the application of lidar, the isoplanatic angle＇s expressions of two deformable mirrors （DMs） MCAO for uplink and downlink are deduced. The effects of conjugate heights for dual-conjugate AO are thoughtfully discussed, and the isoplanatic angles are further analyzed. The results show that the isopanatic angle varies with the conjugate height and reaches the maximum as the conjugate height is at the optimal altitude. Moreover, the optimal conjugate height changes with the propagation distance.     

Quick single-photon detector with many avalanche photo diodes working on the time division

Due to the limit of response speed of the present single-photon detector, the code rate is still too low to come into practical use for the present quantum key distribution (QKD) system.A new idea is put up to design a quick single-photon detector.This quick single-photon detector is composed of a multi-port optic-fiber splitter and many avalanche photo diodes (APDs).Au of the ports with APDs work on the time division and cooperate with a logic discriminating and deciding unit driven by the clock signal.The operation frequency lies on the number N of ports, and can reach N times of the conventional single-photon detector.The single-photon prompt detection can come true for high repetition-rate pulses.The applying of this detector will largely raise the code rate of the QKD, and boost the commercial use.     

Measurement of nonlinear coefficient of optical fiber based on small chirped soliton transmission

We measure the waveform and phase curves of short optical pulses before and after transmission over different lengths of fibers by use of the pulse analyzer with the frequency-resolved optical gating (FROG),and numerically simulate pulse evolution under the experimental conditions.The nonlinear coefficient of the fiber is given by comparing the experimental results with the numerical ones.Difference between the experiment and numerical simulation is analyzed.     

Resonance scattering of canonical elastic shells in absorbing fluid medium

Resonance scattering of elastic spherical shell and cylindrical shell while the surrounding fluid medium has absorption is studied. The normal mode solution derived using exact elastic theory and the separation of variables is still applicable. However, the scattering form function has to be modified for the absorbing medium, otherwise the unreasonable result would be obtained. The backscattering form function in the absorbing medium is redefined, and the form function of elastic spherical and cylindrical shell with vacuum or solid matter filled is calculated in various absorption conditions. The results show that the absorption of surrounding fluid leads to notable attenuation of the coincidence resonances in the mid-frequency, but it has a little influence on the low-frequency resonance scattering induced by the filler inside the shell.