菠菜光系统CP47&RC激发能传递与温度的关系

采用基于延时分次扫描单光子计数器为探测装置的皮秒时间分辨荧光光谱测试系统研究了菠菜光系统(PS )CP47&RC蛋白复合物光能传递与温度的关系。分别对CP47&RC样品在20,42,48℃下做温度处理后,以脉宽为120ps,重复率为4MHz,波长为514nm的Ar+激光作为光源分别激发处理后的样品,对比研究了菠菜CP47&RC激发能传递速度与温度的关系,发现同一波长,不同温度下能量传递速度不同,48℃时能量传递的速度总体变慢;CP47&RC在42℃温浴处理的情况比较特别。

叶片阶段性白化小麦的叶绿体激发能分配和荧光动力学特征

叶片阶段性白化小麦是一种非常特殊的色素突变体。本文对其白色、白绿相嵌及转绿叶片的叶绿体光化活性分别进行了测定。试验表明：（１）白化和白绿相嵌叶片的叶绿体色素合成处于停滞阶段，转绿叶片则处于色素迅速合成阶段；（２）白化、白绿相嵌和转绿叶片叶绿体的激发能传递呈递增趋势；（３）三者对绿体的ＰＳⅡ活性和原初光能转化效率也呈递增趋势；（４）白化叶片叶绿体缺乏ＰＳⅠ和ＰＳⅡ外周天线色素蛋白，白绿相嵌和转绿叶片的类囊体膜多肽组分与正常叶片相近似。

超快微光分子光谱探测技术研究

按照超快极微弱分子吸收光谱学 ,荧光光谱学 ,时间分辨光谱学以及偏振荧光光谱学探测特性 ,设计、集成组建了能够探测紫外 -可见 -红外快到飞秒时间分辨的单分子光学事件的激光瞬态光谱仪 其光源有从 30 0nm到 30 0 0nm连续可调的飞秒激光器、纳秒氢灯及连续氙灯 光谱分辨率达 0 .0 5nm ,在泵浦探测差异吸收下有小于 15 0fs的时间分辨率 谱仪能够实时给出光谱曲线及生物分子组分寿命 利用该谱仪探测了PSⅡCC ,PSⅡRC的能量传递动力学 在 83K温度下PSⅡCC中的 β Car分子接收 5 0 7nm光能 ,以单步跃迁和随机转移的方式通过Chla6 41 56 37/6 38分子传递光能到反应中心Chla6 83 26 80 /6 81,平均传能时间为 77ps ,有 5 9.94 %的组分用 35 5ps时间电荷重组 在PSⅡRC中的 β Car分子接收 5 0 7nm光能 ,由Chla6 41.56 37/6 38分子传递光能通过Chla6 78.26 75.5到反应中心 ,平均传能时间为 88.5ps 在 83K温度下 ,反应中心复合物离子对 [P6 80 + ·pheo ]平均再复合寿命为 19.

Properties of Picosecond Fluorescence of Super High-Yield Hybrid Rice

Thylakoid membrane preparations of super high-yield hybrid rice (Oryza sativa L.), Liangyoupeijiu (P9) and Shanyou 63 (SH 63) were used for investigating its spectral and time properties by using picosecond time-resolved fluorescence spectrum measuring system. The thylakoid membrane preparations of P9 and SH 63 were excited by an Ar+ laser with a pulse width of 120 ps, repetition rate of 4 MHz and wavelength of 514 nm. The time constants of the excited energy transfer in these two varieties at flowering stage and grain filling stage were calculated from the experimental data. Based on the comparative studies of the time and spectral properties of the excited fluorescence in these ultrafast dynamic experiments the following was found: at both the flowering stage and grain filling stage, the speed of the excitation energy transfer, in photosystem was faster than that in photosystem II in P9 variety; and the speed of the excitation energy transfer at grain filling stage was faster than those at flowering stage for both rice varieties; the experiments also implied that the components and assembly of pigments in SH 63, but not in P9, changed during the process from flowering stage to grain filling stage for in these two rice varieties.

Upconversion Luminescence of SrTiO3：Er^3＋ Ultrafine Powders Produced by 785 nm Laser

Er^3＋ doped SrTiO3 ultrafine powders were prepared by solid state reaction in a molten NaCl flux. The structural properties were characterized by X-ray diffraction, field emission scanning electron microscopy, and Fourier transform infrared spectroscopy. The Stokes emission spectra of Er^3＋ in SrTiO3：Er^3＋ ranging from green to near infrared region were investigated under 514.5 nm laser excitation. The green and red upconverted luminescence spectra of Er^3＋ were measured under excitation into the 419/2 level by 785 nm laser. The upconversion mechanisms were studied in detail through laser power dependence and Er^3＋ ion concentration dependence of upconverted emissions, and results show that excited state absorption and energy transfer process are the possible mechanisms for the upconversion. The upconversion properties indicate that SrTiO3：Er^3＋ may be used in upconversion phosphors.

LH2中类胡萝卜素为链孢红素的类球红细菌绿色突变株(GM309)的获得及理化分析

用甲基磺酸乙酯诱变类球红细菌(Rhodobacter sphaeroides 601),分离获得绿色突变株,命名为GM309。吸收光谱分析表明其外周天线色素复合物(LH2)的类胡萝卜素特征吸收峰发生了20nm的蓝移。通过吸收光谱和质谱进一步的分析确定RS601的LH2中类胡萝卜素为球形烯,而GM309的LH2中则变为链孢红素。链孢红素比球形烯少一个共轭双键。CD,吸收光谱分析表明GM309 LH2中色素排列结构与野生LH2相近。比较野生和突变株的LH2荧光发射光谱,发现GM309的LH2仍保持了激发能由类胡萝卜素向细菌叶绿素以及细菌叶绿素B800向B850的传递,其B850的荧光峰为对照的58％,表明激发能由细菌叶绿素B800向B850的传递效率有所降低。研究为了解类胡萝卜素在LH2激发能传递中的作用提供了新的实验手段。

Environment-assisted excitation energy transfer in LH1-RC-type and LH2-type trimers

In this work,we study environment-assisted excitation energy transfer(EET) through calculating energy transfer efficiency(ETE) in LH1-RC-type and LH2-type trimers,which can be used to mimic energy transfer behaviors in the basic unit cells of LH1-RC and LH2 light-harvesting complexes.Quantum state evolution of the trimers is described by a non-Hermitian quantum master equation.ETE in these trimer systems is investigated by the use of numerical solutions at finite temperatures for the non-Hermitian master equation.We theoretically reveal the temperature-assisted ETE enhancement.It is found that highly efficient EET with nearly unit efficiency may occur in the nearby regime of the critical point of quantum phase transition.

Enhanced cooperative near-infrared quantum cutting in Pr～(3+)-Yb～(3+)co-doped phosphate glass

Pr3+and Yb3+co-doped phosphate glasses are prepared to study their optical properties.Excitation and emission spectra and decay curves are used to characterize their luminescence.We demonstrate that upon excitation of Pr3+ion with one high energy photon at 470 nm,two near-infrared(NIR)photons are emitted at 950-1100 nm(Yb3+:2F 5/2 →2F 7/2)through an efficient cooperative energy transfer(CET)from Pr3+to Yb3+.The maximum energy transfer efficiency(ETE)and the corresponding quantum efficiency approach up to 90.17%and 190.17%,respectively.The glass materials might find potential application for improving the efficiency of silicon-based solar cells.