高等植物光合作用能量传递机理和团簇分子电子结构性质的研究

【作者】 任兆玉；

【导师】 侯洵； 王水才；

【作者基本信息】 西北大学 ， 理论物理， 2002， 博士

【摘要】 本论文《高等植物光合作用能量传递机理和团簇分子电子结构性质的研究》分为上下两篇。上篇“高等植物光系统Ⅱ光能传递超快动力学研究”为论文的主要内容，该部分工作是在中国科学院西安光机所瞬态光学实验室完成的，属于九五国家重点基础研究发展规划项目《光合作用高效能量转化机理及其在农业中的应用》的子课题中的一部分研究成果。下篇“半导体团簇电子结构性质的理论研究”，是在西北大学光子学与光子技术研究所进行的研究工作。 一、上篇内容及创新点： 1．全面综述了光合作用研究的意义、原初反应过程当前研究的进展、PSⅡ的生物结构和功能；讨论了PSⅡ中能量传递的超快速原初过程光能的吸收、传递与陷获的物理机制以及电子迁移理论；简要介绍了超短光脉冲技术和超快光谱技术的发展及其在生物、物理和化学领域内的应用潜力以及几种超快速光谱技术的实现方法和技术问题。 2．在介绍了超快速光谱测量中常用的数据处理方法之后，根据我们实验测量的荧光数据特点，首次运用信号处理中的小波分析法对实测信号进行降噪，采用非线性最小二乘法，用Matlab语言建立了自己的数据处理软件。 3．建立了以倍频Ti：sapphire飞秒激光器(波长400nm，脉宽120fs，重复率82MHz)光源，光电倍增管为探测器，采用Boxcar采集数据的飞秒荧光光谱测量系统；用该系统对菠菜光系统Ⅱ外周天线复合(LHCⅡ)、核心复合物(CP)样品进行了的超快动力学实验研究，的出如下结论：(1)能量在LHCⅡ的叶绿素中传递的时间常数分别为：320fs、4.0ps、20.0ps。相对应的各组分荧光占总荧光的百分比分别为：3.4％、50％、46.6％；(2)能量在核心复合物的叶绿素中传递的时间常数分别为:3.9ps、20.4ps、930.5ps。各组分荧光色素占总荧光色素的百分比分别为：1.0％、12.7％、86.3％；(3)通过分析时间常数与色素成分之间的对应关系，画出了能量传递能级关系图。 4．创新性地研制并建立了以Ar~+激光(波长514nm，脉宽120ps，重复率4MHz)为光源，雪崩光电二极管为探测器的，基于延时分幅扫描单光子计数系统的皮秒时间分辨荧光光谱测量系统。该系统可以最大可能的发挥光电探测器的优越性，将 摘 要一 系窕迎虹团销蹈骏暄【上互造。该系统具有很高的信噪比和灵敏度，可以对5 PW 以上的光信号响应。5．首次运用皮秒时间分辨荧光光谱装置对陀H核心复合物、核心天线CP43，CN7、 CP47＆RC等样品，进行了温度处理的比较研究，根据在三种温度（20”C、42”C、 48℃）处理下的荧光光谱特性和时间特性的研究结果，发现在光系统＊中：（l） 3Utheqili81tti＆sffi3dEI；2） Bhl．－－－－－－－－－－－－－－－－－－－－－－－－－－。3）n 一 剿娥腹盛团j划J进圈拒喧铡幽幽肛趾昭。（第二点结论未见有文献 报）6．首次运用皮秒分辨扫描单光子计数荧光光谱装置对高产水稻及其田间叶色突变体 （编号为249－rCen，249寸ellow＊以及两种高产杂交水稻＊优培九0）和釉型 杂交水稻汕优63（SH 63）分别在扬花期和灌浆期的内囊体膜进行了超快动力学 实验，得出了规律性的结论： l）．249－rCen，249－yCllow两种样品共同的特点是：丛匾匐隆巨劳L逼遏眨 jatllZEAIMANglgltsppE：lasuan＝＝；b）．glZllZxHllfLnk — —。 2X＊9和8H63两种水稻：刃．无丞邑坠B图盼囫变愧诞激b狗凋陵剑赠瞳 M＆A122＆lllZZ；b）．－0 （上述六种样品站稻的超快动力学实验研究和结论均未见有文献报道。） 二、下篇主要内容及创新点：1．综述了碳族团簇研究状况及其进展和用于团簇材料设计的密度泛函理论基础，以 及当前微观领域内材料设计的研究动态与展望。2．用密度泛函理论在B3LYP65 u，P）水平下对Ge0和Ge人”（n＝16）团簇的 几何稳定性的理论研究，得到了最稳定几何构型。发现几何参数、Egap，断裂能， Ge在 和冈口“e 16）的GeC键的交错布居、Mllilien原子净布居以及Ge（ 键长都受所增加的额外电荷的影响。苞亘站L臼殒政J吐茎渔趾gJ酗在E 厦五敛因壹二h匕臼朗猖L粤论结果表明，坠位wd戈幽遗困俐劲凶陛过画 2 摘 要 — — 一 — —。 3．用半经验理论在AMI水平下对戮人n＝26占6，60）笼的几何构型作了优化处理和频率 分析，给出并讨论了出n笼的稳定性、结构以及EgaP。理论结果表明所有8n（＝26上6，。60）笼经过轻微的畸变形成更稳定的结构。垦瞳朝睦述闪应蔓团囫姻啦。在从 硅笼的Sidsi。环移走一个硅原子之后，出现了一个新的Sp‘杂化出原子，它对新 形成的团。－l笼的稳定性有一定贡献。坠妞28凶迎笼狙到圆司纽刨匠轴L更多还原

【Abstract】 The dissertation, "the study of photosynthesis mechanism of higher plants and electronic structure properties of clusters", has two parts. The main part, "ultrafast dynamic study on energy transfer in Photosystem II of photosynthesis", is the sub-subject of "photosynthesis high efficiency light energy transfer mechanism and its application in agriculture" which is a key basic research and development plan, has been studied by ultrafast spectroscopy in State Key Laboratory of Transience Optics Technology Xi’an Institute of Optics and Academy of Sciences. The second part, "Theoretical investigation on the electronic properties of semiconductor clusters", is the study with regard to the work of Institute of Laboratory Optics Technology and Photonitics where I study for my diploma of Ph. D.The key contents of the topic on the main part are follows:1. The information concerning: the signification of the study on photosynthesis, the study process of primary reactions, biological structure its function of PSII, the development of ultsashort pulse laser and ultrafast spectroscopy techniques and their application in Physics, Chemistry and Biology is summarized in detail. The mechanism of light harvest, transfer and trap and electron transfer process in PSII was discussed.2.The methods of data processing in measurement of time-resolved spectra have been analyzed. Small wave analysis was first used in debasing noise. Computer software of data processing with the function of nonlinear least-square deconvolution is developed.3. A setup of femtosecond time-resolved fluorescence spectroscopy is established with Tiisapphire femtosecond laser bumped by Ar+ laser, frequency double, monochromatic, photoelectric multiplier tube and boxcar as its major components.4.Fluorescence spectroscopic and time property of light-harvesting complex (LHCII) and core complex, which was isolated from spinach inphotosystem II was investigated using the setup mentioned in number 3. Theconclusions were drawn from tijie analysis experiment results: l).In LHC II,three lifetime components (326 fs.4.0 DS and 20.0 ns) were detftr.te.H bv multi-exponential curve fitting method. The fluorescence ratio of each component to whole component) is 3.4%, 50% and 46.6%, respectively. The figure of the light absorbed ana transferred has been drawn according to the structural and fluorescence spectroscopy property of LHC II. 2). In core complex, three lifetime components were detected by multi-exponential and non-linear least square curve fitting. Those components are 3.9 DS, 20.4 DS and 930.5 DS. The fluorescence pigments ratio of each component to the whole is 1.0%, 12.7% and 86.3%, respectively. The figure of the light absorbed and transferred has been drawn according to the structural and fluorescence spectroscopy property of core complex, also.5.A novel method of Picosecond-resolving fluorescence spectrum measurement with delay-frame-scanning single photon counting technique was introduced. This spectrum setup was made innovatively. The time resolving Dower was improved 16.7 times by delay-frame-scanning technique. The advantage of avalanche photoelectric detector (APD) with rapid response was exerted mostly. It also has high property of signal-to-noise ration and sensitivity (5 pw light could response).6.The setup, which is mentioned in number 5, has been used in studying the sample of core complex, core antenna CP43, CP47, CP47&RC that was isolated from spinach in photosystem II. Those samples were treated in hot water 5 minutes with temperature at 20?C, 42?C and 48?C, respectively before the measurement. Comparing the data we got from the every sample experiment in different temperature, the conclusions were that: 1). The rates of the enerev transferred are varied at different wavelength. 2). The. rate of theenergy transferred becoming slower with the wavelength bigger. 3). Some special evidence at 42?C have been found especially CP47, it might have been a critical temperament which the protein complex were disass更多还原