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Enhancement of the Femtosecond Third Harmonic Generation by Charge Transfer Process in Poly (N-Vinylcarbazole) /C_(60) Film

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Chinese Physics Letters 1997年第5期14卷 356-359页

作者： qian Jiang ZHAO Li WANG Gong-ming qian shi-xiong LIU Xian-nian ZHENG Qi-ke Department of Physics Fudan UniversityShanghai 200433 Laser Chemistry Institute Fudan UniversityShanghai 200433

The femtosecond third harmonic generaction(THG)output has been measured from a series of poly(N-vinylcarbazole)(PVK),C_(60),mixed and multilayer PVK/C_(60) films which were all fabricated by physical jet deposition *** is an enhancement of femtosecond THG output from the mixed PVK/C_(60) film in comparison with other *** transfer complex in the mixed PVK/C_(60) film was considered to be the main reason for this increase of the third-order susceptibility.

关键词： technique. Femto femtosecond

Fragmentation Mechanism of Fullerenes in the Positive and Negative Ion Channels

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Chinese Physics Letters 2001年第8期18卷 1056-1059页

作者： KONG Qing-Yu ZHAO Li ZHUANG Jun qian shi-xiong LI Yu-Fen State Key Joint Laboratory for Materials Modification by Laser Ion and Electron Beamsand Department of PhysicsFudan UniversityShanghai 200433

The authors have performed the photofragmentation studies of pristine C_(60) and C_(60)/C_(70) composites on the reflectron time-of-flight mass spectrometer(RTOF MS)in the positive and negative ion *** mechanism of the formation of daughter fullerenes in the negative ion channel and the enhancement of fullerene coalescence reactions have been discussed compared to our previous studies on the linear *** 5 cm free expansion path in the RTOF experiments provides sufficient time and favorable environment for the electrons to attach to the neutral daughter species,so it is thought to play a key role for the appearance of strong mass peaks of anionic fragmentation and aggregation fullerene *** appearance of odd-numbered“fullerene”fragments is briefly discussed.

关键词： fragmentation (MS) neutral

Anomalous Photofragmentation of Fullerene Doped in Silica Aerogel-Enhanced Formation of Odd-Numbered "Fullerene" Fragments

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Chinese Physics Letters 2001年第12期18卷 1578-1581页

作者： KONG Qing-Yu ZHAO Li ZHUANG Jun qian shi-xiong LI Yu-Fen WANG Jue Department of Physics Fudan UniversityShanghai 2004332 State Key Joint Laboratory for Materials ModiGcation by Laser Ion and Electron BeamsFudan UniversityShanghai 2004333 Pohl Institute of Solid State Physics Tongji UniversityShanghai 200092

Photofragmentation of fullerene-doped silica aerogels has been investigated by the excimer laser ablation reflectron time-of-flight mass spectrometric technique. Great enhancement in the formation of odd-numbered ‘fullerene’ fragments has been observed in the negative-ion channel for the chemically doped aerogel sample. Generally, oddnumbered species C57, C55, C53 and C51 appeared in the mass spectra. Under optimM experimental conditions C55 can be even more intense than the neighbouring even-numbered carbon clusters. In contrast, for the physicallydoped sample, just like pristine C6o, only weak odd-numbered fragments were observed. In the positive-ion channel, the behaviour of all these samples is similar, no odd-numbered species was ever detected. A mechanism related to the interaction between the fullerene dopant and the silica aerogel host is suggested for the anomalous enhancement of the odd-numbered duster formation. A preliminary discussion on the structures of the oddnumbered‘fullerene’ fragments is given.

关键词： technique fragmentation silica

Photoinduced Charge Transfer in MBB-PPV/C_(60) Composite Film

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Chinese Physics Letters 2000年第11期17卷 829-831页

作者： GUO Li-Jun MA Guo-Hong SHAN Fu-Kai MO Yu-Jun qian shi-xiong Department of Physics Fudan UniversityShanghai 200433 Department of Physics Henan UniversityKaifeng 475001

The photoconductive properties of MBB-PPV/C_(60) composite films fabricated by the physical jet deposition(PJD)technique have been studied on the basis of the photoinduced charge transfer *** the photoex-citation,the transverse photoconductivity of the composite films is greatly enhanced by 4 orders of magnitude due to the efficient excitation transfer process from MBB-PPV(as donor)to C_(60)(as acceptor)occurring at the interface,the separation of charges and the existence of in-layer free *** results indicate that the conjugated polymer/fullerene composite films optimized by an appropriate configuration have potential applications in photoelectric devices and photonic fields.

关键词： composite V/C films

Singlet Exciton Migration in a Conjugated Polymer by Picosecond Time-Resolved Photoluminescence

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Chinese Physics Letters 2001年第7期18卷 944-946页

作者： MA Guo-Hong qian shi-xiong LEI Hong WANG He-Zhou WANG Rong-Qiu LI Yong-Fang Department of Physics Fudan UniversityShanghai 200433 Key Laboratory of Applied Surface Physics Fudan UniversityShanghai 200433 Institute of Ultrafast Laser Spectroscopy Zhongshan UniversityGuangzhou 510275 Institute of Chemistry Chinese Academy of SciencesBeijing 100080

The transient photoluminescence(PL)of DO-PPV(poly-(2,5-dioctyloxy-1,4-phenylene vinylene))solution in chloroform was investigated by picosecond time-resolved PL *** ultrafast rise of PL and the following single exponential decay with a time constant about 400ps were assigned to the formation of intrachain exciton and its decay process,*** redshift of the PL emission spectrum with time was caused by the subsequent exciton migration among the different conjugated segments in the DO-PPV polymer.

关键词： spectroscopy. decay exponential

Energy Transfer Pathways in Reaction Center upon Femtosecond Excitation of Accessory Bacteriochlorophylls

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Chinese Physics Letters 2001年第4期18卷 522-524页

作者： GUO Li-Jun MA Guo-Hong ZOU Yong-Long XU Chun-He LIU Ye MI Jun qian shi-xiong LIU Jian-Hua Department of Physics Fudan UniversityShanghai 200433 Shanghai Institute of Plant Physiology Chinese Academy of SciencesShanghai 200032

The energy transfer pathways from the excited accessorybacteriochlorophylls (B*) within native and modified (pheophytin-exchanged) reaction center isolated from Rhodobactersphaeroides (RS601) have been investigated by using the femtosecond pump-probe technique. For native RS601, B* decays with time constant of 240 fs, followed by a partial recovery of the ground state bleaching with time scale of about 2 ps. In modified RS601(Phe), however, B* decays with time constant of 800 fs for magic angle (54.7°) polarization configuration. In addition to the general assumption of energy transfer pathway from B* to the special pair P, an alternative pathway for energy transfer probably operates as well.

关键词： technique. decay excited

Irradiation Effects of Femtosecond Pulses on Refractive Index of Ag-Embedded Nanocomposite Glasses

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Chinese Physics Letters 2010年第2期27卷 288-291页

作者：董志伟钱士雄杨修春陈德应 National Key Laboratory of Tunable Laser Technology Harbin Institute of Technology Harbin 150001 School of Materials Science and Engineering Tongji University Shanghai 200433 Surface Physics Laboratory (National Key Laboratory) and Physics Department Fudan University Shanghai 200433

The irradiation effects of femtosecond pulses on Ag-embedded composite glasses fabricated by ion-exchange are investigated using z-scan measurement. Both changes of the refractive index caused by the laser irradiation effect and the third-order optical nonlinearity are observed in the experiment. Taking the change of the linear and nonlinear refractive index into consideration, the fitting results are in agreement with the experimental results.

关键词： Condensed matter: electrical magnetic and optical Optics quantum optics and lasers Nanoscale science and low-D systems Condensed matter: structural mechanical & thermal

Structural Origin of the Formation of Odd-Numbered Carbon Clusters from Fullerene Derivatives

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Chinese Physics Letters 2000年第6期17卷 419-421页

作者： KONG Qing-Yu ZHUANG Jun ZHAO Li WANG Jia-Yu qian shi-xiong LI Yu-Fen LI Xu ZHONG Chao-Fan CAI Rui-Fang YU Yong HOU Hui-Qi State Key Joint Laboratory for Materials ModiScation by Laser Ion and Electron BeamsDepartment of PhysicsFudan UniversityShanghai 200433 Department of Chemistry Fudan UniversityShanghai 200433 Department of Environmental Science and Engineering Fudan UniversityShanghai 200433

We report the mass spectrometric investigation on fullerene derivatives C_(60)CH_(2),C_(60)RH,C_(60)R_(2)(R=C_(6)H_(5)CO-)and C_(60)O_(n)under the 308nm laser *** the negative ion mass spectra of C_(60)CH_(2)C_(60)R_(2),and C_(60)O_(n),odd-numbered clusters C_(57)^(-),C_(55)^(-),C_(53)^(-),C_(51)^(-)are observed clearly in addition to the even-numbered fullerene fragment ions,while for the monoadduct C60RH,odd-numbered species can not be *** the positive ion channel,the fragmentation patterns of the three derivatives are similar.A mechanism related to the structural characteristics of the derivatives is supposed for the odd-numbered duster *** 3-membered ring formed on the C_(60)cage is thought of to play a vital role for the formation of odd-numbered carbon clusters.

关键词： membered fragmentation addition

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InP纳米颗粒的超快动力学和光学非线性

光谱学与光谱分析 2006年第9期26卷 1742-1745页

作者：李丹杨合晴梁春军钱士雄北京交通大学物理系北京100044 陕西师范大学化学与材料科学学院陕西西安710062 复旦大学物理系上海200433

通过飞秒泵浦-探测方法测量了波长为800nm时InP半导体纳米颗粒激发态的瞬态动力学过程。观察到一个快速的光致漂白建立和一个漂白的恢复过程,分析饱和吸收的来源可能是带填充效应引起跃迁的饱和吸收。对于漂白恢复中的快过程是由于自由... 详细信息

通过飞秒泵浦-探测方法测量了波长为800nm时InP半导体纳米颗粒激发态的瞬态动力学过程。观察到一个快速的光致漂白建立和一个漂白的恢复过程,分析饱和吸收的来源可能是带填充效应引起跃迁的饱和吸收。对于漂白恢复中的快过程是由于自由载流子的弛豫,而慢成分是由于光激发载流子在很短的时间内受陷于表面态形成的限域载流子的弛豫。通过飞秒光克尔效应(OKE)方法测量材料的超快非线性响应曲线,计算了材料的光学三阶非线性极化率,分析了非线性的来源。

关键词： InP 纳米颗粒飞秒泵浦-探测光学非线性