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Energy Transfer among Chlorophylls in Trimeric Light-harvesting Complex Ⅱ of Bryopsis corticulans

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Acta Biochimica et Biophysica Sinica 2006年第5期38卷 310-317页

作者： Su-Juan ZHANG~(1,2.)Shui-Cai WANG~2.Jun-Fang HE~2.Hui CHEN~3 1 Institute of Photonics and Photo-Technology,Northwest University,xi'an 710069,china 2.State Key Laboratory of Transient {2. and Photonics,xi 'an Institute of {2. and precision mechanics,chinese academy of sciences,xi'an 710068.china 3 Laboratoty of Photosynthesis Basic Research,Institute of Botany,chinese academy of sciences,Beijing 100093,china Institute of Photonics and Photo-Technology Northwest UniversityXi'an 710069 China State Key Laboratory of Transient optics and Photonics Xi'an Institute of Optics and Precision Mechanics Chinese Academy of SciencesXi'an 710068 China Laboratory of Photosynthesis Basic Research Institute of Botany Chinese Academy of SciencesBeijing 100093 China

A study on energy transfer among chlorophylls（Chls）in the trimeric unit of the major light-harvesting complex Ⅱ（LHC Ⅱ）from Bryopsis corriculan,was carried out using time-correlated singlephoton *** the chlorophyll Q region of LHC Ⅱ,six molecules characterized as Chlb62.,Chlb646,Chlb652.54,657,Chla664666,Chla674677.680and Chla682.83were discriminated according to their absorption spectrumand fluorescence emission ***,excited by pulsed light of 62. nm,fluorescence kinetics spectrain the chlorophyll Q region were *** accordance with the principles of fluorescence kinetics,thesekinetics data were analyzed with a multi-exponential *** constants on energy transfer were *** overwhelming percentage of energy transfer among chlorophylls undergoes a process longer than 97picoseconds（ps）,which shows that,before transferring energy to another Chl,the excited Chl might convertenergy to vibrations of a lower state with different multiplicity（intersystem crossing）.Energy transfer at thelevel of approximately 10 ps was also obtained,which was interpreted as the excited Chls may go throughinternal conversion before transferring energy to another *** with a higher standard deviation,timeconstants at the femtosecond level can not be entirely excluded,which can be attributed to the ultrafastprocess of direct energy *** to the arrangement and direction of the dipole moment of Chls inLHC Ⅱ,the probability of these processes is *** fluorescence lifetimes of Chlb652.54,657,Chla664666,Chla674677.680and Chla682.83were determined to be 1.44ns,1.43 ns,636 ps and 713 ps,*** of energy dissipation in the pathway of fluorescence emission were no more than 40% in thetrimeric unit of LHC Ⅱ.These results are important for a better understanding of the relationship between thestructure and function of LHC Ⅱ.

关键词： energy transfer LHC Ⅱ transient spectrum fluorescence kinetics

Cobalt-catalyzed reductive alkynylation to construct C(sp)-C(sp^(3))and C(sp)-C(sp^(2.)bonds

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chinese Chemical Letters 2024年第7期35卷 253-258页

作者： Lei Wan Yizhou Tong xi Lu Yao Fu Hefei National Research Center for Physical sciences at the Microscale iChEMCAS Key Laboratory of Urban Pollutant ConversionAnhui Province Key Laboratory of Biomass Clean EnergyUniversity of Science and Technology of ChinaHefei 230026China Key Laboratory of precision and Intelligent Chemistry School of Chemistry and Materials ScienceUniversity of Science and Technology of ChinaHefei 230026China

Transition-metal-catalyzed cross-electrophile coupling has emerged as a reliable method for constructing carbon–carbon ***,we report a general method,cobalt-catalyzed reductive alkynylation,to construct C(sp)-C(sp^(3))and C(sp)-C(sp^(2.)*** presented reaction has a broad substrate scope,enabling the efficient cross-electrophile coupling between alkynyl bromides with alkyl halides and aryl or alkenyl(pseudo)*** presented reaction is conducted under mild conditions,tolerating many functional groups,thus suitable for the modification and synthesis of biologically active molecules.

关键词： Cobalt-catalysis Cross-electrophile coupling Carbon-carbon bond formation Reductive alkynylation Alkyne synthesis

Recent Advances in Cobalt-Catalyzed Regio-or Stereoselective Hydrofunctionalization of Alkenes and Alkynes

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CCS Chemistry 2024年第5期6卷 1130-1156页

作者： Yan Li xi Lu Yao Fu Hefei National Research Center for Physical sciences at the Microscale CAS Key Laboratory of Urban Pollutant ConversionAnhui Province Key Laboratory of Biomass Clean EnergyUniversity of Science and Technology of ChinaHefei 230026 Key Laboratory of precision and Intelligent Chemistry Department of Applied ChemistrySchool of Chemistry and Materials ScienceUniversity of Science and Technology of ChinaHefei 230026

Hydrofunctionalization of alkenes and alkynes is increasingly important in preparing and modifying carbon-centered organic molecules such as pharmaceuticals,agrochemicals,andmaterial *** development of transition-metal-catalysts has revolutionized the hydrofunctionalization of unsaturated hydrocarbons,greatly improving the synthetic efficiency and selectivity of these *** recent years,notable progress has been achieved in low-cost metal-catalyzed alkene and alkyne hydrofunctionalization reactions following the utilization of traditional precious metal catalysts,including palladium,platinum,and ***-abundant cobalt catalysts,which are low in toxicity and exhibit unique reactivity and selectivity,are widely implemented in academic and industrial *** this review,we highlight recent examples of cobalt-catalyzed hydrofunctionalization of alkenes and alkynes to provide an overview of hydrofunctionalization methods,particularly hydroalkylation *** reactions greatly expand the scope and utility of cobalt-catalyzed couplings of carbon—carbon *** also highlight the mechanistic considerations and selective determinants *** hope our discussion will be informative for future developments in cobalt catalysis and hydrofunctionalization reactions.

关键词： hydrofunctionalization cobalt-catalysis alkene alkyne regioselectivity stereoselectivity

Fabrication of sub-micro size PZT array and their ferroelectric properties

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Science china(Technological sciences) 2006年第6期49卷 693-700页

作者： ZHAO Gaoyang1, ZHANG Weihua1, XU Guomin1, DENG xiaocui1, JIANG Bailing1 & ZHAO Wei2.1. School of Materials Science and Engineering, xi’an University of Technology, xi’an 710048, china 2. xi’an Institute of optics and precision mechanics of CAS, xi’an 710048, china 1. School of Materials Science and Engineering Xi’an University of Technology Xi’an 710048 China 2. xi’an Institute of optics and {2. mechanics of CAS Xi’an 710048 China

The photosensitive PZT sols and their gel films were prepared by sol-gel process. Based on the photosensitivity of the PZT gel films, two-dimensional (2.) array of the PZT gel film was fabricated using twice-exposure of double-beam interference on the gel film. PZT gel films coated on ITO/quartz substrate were exposed to an interference fringe of 32. He-Cd laser beams, the substrate was rotated by 90° between the first and second irradiation steps. Island type periodic 2. array structures with a pitch of 1 μm and cell size of about 480 nm × 480 nm × 40 nm were formed after the irradiation, and followed by leaching with organic solvent, and then by heat treatment at 600°C for 15 min. The hysteresis loops of the cell in PZT array were in-situ measured by the online-operation of TF analyzer and atomic force microscope (AFM). The probe can be located on the locked cell of PZT array in the AFM image. The alternating voltage applied to the locked cell is supplied by the TF analyzer through the conductive coating probe, and then the test signal is fed back to the TF analyzer to obtain the hysteresis loop of the locked cell of array in the absence of top electrode. The results show that the sub-micro size PZT arrays prepared in this way are of polarization reversal characteristics with the alternating electric fields, thereby exhibiting obvious ferroelectricity.

关键词： PZT, ferroelectric films, photosensitivity, hysteresis loop.

Electronic structure and magnetism of Fe-doped SiC nanotubes

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Science china(Physics,mechanics & Astronomy) 2010年第9期53卷 1582-1589页

作者： ZHANG WeiHu1,2.3,ZHANG FuChun3,ZHANG ZhiYong4,LU ShuYuan5 & YANG YanNing3 1 xi’an Institute of optics and {2. mechanics,chinese academy of sciences,xi’an 710068,china 2.Graduate University of chinese academy of sciences,Beijing 100049,china 3 College of Physics and Electronic Information,Yan’an University,Yan’an 716000,china 4 Information Science and Technology Institution,Northwest University,xi’an 71012.,china 5 Department of Telecommunications,xi’an Institute of Posts and Telecommunications,xi’an 71012.,china 1. xi’an Institute of optics and {2. mechanics Chinese Academy of Sciences Xi’an 710068 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China3. College of Physics and Electronic Information Yan’an University Yan’an 716000 China4. Information Science and Technology Institution Northwest University Xi’an 710127 China5. Department of Telecommunications Xi’an Institute of Posts and Telecommunications Xi’an 710121 China

The electronic structure and magnetic properties of Fe-doped SiC nanotubes are investigated by using the first-principles method based on density functional theory(DFT) in the local spin density approximation(LSDA).The calculation results indicate that the SiC nanotube of Fe substitution for C exhibits antiferromagnetism while ferromagnetism features prominently when Fe substitutes *** is a kind of half-metal magnetic *** formation energy calculation results show that the formation energy of ferromagnetic structure is 3.2.eV lower than that of antiferromagnetic *** atoms are more likely to replace Si ***-orbit coupling induces electron spin polarization in the ground ***,the doping Fe atoms make relaxation towards the outside of the tube to some extent and larger geometric distortion occurs when Fe substitutes C,but the whole geometric structure of SiC nanotubes is not damaged due to the *** is revealed in the calculation of energy band structure and density of states that more dispersed distribution of energy levels is produced near the Fermi *** Fe substitution for Si,obviously there are spin-split and intense p-d hybrid effects by Si 3p electron spins and Fe 3d electron spins localized at the exchanging interactions between magnetic transitional metal(TM) *** electronic density results indicate that system magnetic moments are mainly generated by the unpaired 3d electrons of Fe *** these results show that the transition metal doping SiC nanotube could be a potential route to fabricating the promising magnetic materials.

关键词： SiC nanotube the first-principles doped magnetic properties

Experimental study on high power all-fiber laser

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chinese optics Letters 2010年第4期8卷 404-406页

作者：赵保银段开椋赵卫李成王屹山 State Key Laboratory of Transient optics and Photonics xi'an Institute of optics and precision mechanics Chinese Academy of Sciences Graduate University of chinese academy of sciences

A high power all-fiber laser is experimentally studied.A monolithic fiber laser system with only one stage of resonator cavity is constructed and 404-W continuous wave（CW） output power is *** opticalto -optical conversion efficiency is up to 64%.The laser central wavelength is at 1081 nm with the spectral full-width at half-maximum（FWHM） of 2.*** laser setup can work with excellent stability;in the long time of high power operation,no thermal distortions or damages are observed.

关键词： Conversion efficiency

A study on volunteer augmentation navigation technology

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Science china(Physics,mechanics & Astronomy) 2011年第6期54卷 1029-1034页

作者： WU HaiTao 1,2.LU xiaoChun 1,2.ZOU DeCai 1,2.& HAN Tao 1,2.1 National Time Service Center,chinese {2. of sciences,xi’an 710600,china 2.Key Laboratory of precision Navigation and Timing Technology,chinese {2. of sciences,xi’an 710600,china 1. National Time Service Center Chinese Academy of Sciences Xi’an 710600 China2. Key Laboratory of Precision Navigation and Timing Technology Chinese Academy of Sciences Xi’an 710600 China

Navigation augmentation technology is one of the most common methods to increase the continuity,reliability and integrity of the global satellite navigation *** concept of volunteer augmentation navigation (VNA) is proposed and the elements and topological structure of VNA are also analyzed in this *** study focuses on the neural network model that volunteers and ordinary users use modern communication information network to exchange self-organizing *** neural cell model of Volunteer Augmentation Navigation using shared information is *** interactive general relative positioning is *** basic theories and methods of volunteer augmentation navigation are formed on the basis of the above-mentioned *** study of realization mechanism of volunteer augmentation technology helps to form a relatively integral architecture of volunteer augmentation navigation.A user self-service satellite navigation augmentation which combines information exchange and navigation services may strengthen the continuity,reliability and integrity of the navigation *** volunteer augmentation navigation theory proposed in this paper improves the traditional satellite navigation application model and expands the connotation and denotation of satellite navigation augmentation methods.

关键词： volunteer augmentation navigation self-organizing information exchange interactive general relative positioning

Preparations on Several GRIN Lenses

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光学学报 2003年第S1期23卷 23-24页

作者： Li Yulin, Wang Weiping, Zhang xiangdong, Huo Junmin (xi’an Institute of {2. & precision mechanics, The chinese academy of sciences xi抋n Institute of optics & {2. mechanics The Chinese Academy of Sciences

Gradient index materials have been developed from glass melting process to GRIN lenses. Two kinds of GRIN lenses have been fabricated by ion-exchange and glass fusion/diffusion. The main applications to GRIN lenses ar... 详细信息

关键词： have GR of in been Preparations on Several GRIN Lenses on

Studies　on　Passive　Mode－Locking　Characteristics　of　Nd：YAG　Laser　With　a　Nonlinear　Coupled－Cavity

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chinese Journal of Lasers 1995年第1期B4卷 19-24页

作者： CHENG Zhao XU Dalun(State Key Laboratory of Transient optics and Technology,xi an Institute of optics and precision mechanics,Academia Sinica,xi,an 710068, china) xi'an Inst of optics and {2. Mechanics Xi'an China

ＳｔｕｄｉｅｓｏｎＰａｓｓｉｖｅＭｏｄｅ－ＬｏｃｋｉｎｇＣｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆＮｄ：ＹＡＧＬａｓｅｒＷｉｔｈａＮｏｎｌｉｎｅａｒＣｏｕｐｌｅｄ－ＣａｖｉｔｙＳｔｕｄｉｅｓｏｎＰａｓｓｉｖｅＭｏｄｅ－Ｌｏｃ... 详细信息

ＳｔｕｄｉｅｓｏｎＰａｓｓｉｖｅＭｏｄｅ－ＬｏｃｋｉｎｇＣｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆＮｄ：ＹＡＧＬａｓｅｒＷｉｔｈａＮｏｎｌｉｎｅａｒＣｏｕｐｌｅｄ－ＣａｖｉｔｙＳｔｕｄｉｅｓｏｎＰａｓｓｉｖｅＭｏｄｅ－ＬｏｃｋｉｎｇＣｈａｒａｃｔｅｒｉｓｔｉ...

关键词： Coupled-cavity mode locking resonant passive mode-locking high-repetition-rate laser