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Ultrafast excitation relaxation in light-harvesting complex LH2.from *** 601

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Science china Chemistry 2004年第3期47卷 192-199页

作者： GUO Lijun1,2. LIU Yuan3. LIU Weimin2. GUO Junhua1, XU Chunhe3.& QIAN Shixiong2.1. {3. of Physics and Information Optoelectronics, Henan University, Kaifeng 475001, china 2. Physics Department, Fudan University, Shanghai 2.043., china 3. Shanghai Institute of Plant Physiology, chinese Academy of sciences, Shanghai 2.003.0} china school of Physics and Information Optoelectronics Henan University Kaifeng China Physics Department Fudan University Shanghai China Shanghai Institute of Plant Physiology Chinese Academy of Sciences Shanghai China

The energy relaxation and kinetic evolution of transient spectra of bacteriochloro- phylls (BChls) in light-harvesting complex LH2.from Rb. sphaeroides 601 were investigated using femtosecond pump-probe technique. Upon 783.nm excitation, the energy at B800 BChls ex-periences an intramolecular redistribution with 0.3. ps time constant before transferring to B850 BChls. With tuning the excitation wavelength, the dynamical evolution of excited BChls was clearly observed, which indicates an obvious competition between the ground state bleaching and excited state absorption (ESA) of BChls involved and an isosbestic point near 818 nm, and also demonstrates that from the lower electronic excited state of B800 BChls to the higher exci-tonic state of B850 BChls is an efficient routine for energy transfer. The excitation energy in higher excitonic states of B850 BChls relaxes rapidly to the next lowest excitonic state by inter-conversion, delocalization to adjacent molecular, populating the lowest excitonic state and the change of molecular conformation.

关键词： photosynthesis, light-harvesting complex, energy transfer, ultrafast, dynamics, purple bacteria.

Re-Os(ICP-MS)dating of the massive sulfide ores from the Jinchuan Ni-Cu-PGE deposit

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Science china Earth sciences 2005年第10期48卷 1672-1677页

作者： YANG Gang1,2. DU Andao1, LU Jiren3. QU Wenjun1 & CHEN Jiangfeng2.1. National Research Center of Geoanalysis, Beijing 10003.,{3. 2. Laboratory for Earth Material Cycling, {2. of Earth and Space sciences, University of Science and Technology of{3., Hefei 2.002.,{3. 3. Institute of Mineral Resource, chinese Academy of Geological sciences, Beijing 10003.,{3. National Research Center of Geoanalysis University of Science and Technology of china chinese Academy of Geological sciences

Massive sulfide ore from the Jinchuan Ni-Cu-PGE deposit was dated by Re-Os technique using Carius Tube digestion, Os distillation, Re extraction by acetone and ICP-MS measurement. An isochron giving an age of 83. ± 3. Ma, initial 187Os/188Os ratio of 0.2.9 ± 0.018 (MSWD = 1.7) and γOs = 13. ± 15 is obtained. The Re-Os age obtained agrees, within analytical uncertainties, with previous SHRIMP zircon U-Pb age of 82. ± 8 Ma (n=5, MSWD = 4.3.. The result suggests that the deposit was formed at Neoproterozoic and that the formation of the Jinchuan Ni-Cu-PGE sulfide deposit may be closely related to the plume activity, which were attributed to the breakup of the Rodinia supercontinent. The high γOs of the massive ores sug-gests that crustal material was involved in the formation of the Jinchuan deposit, however, the quantity of the added crustal material is less than 10%.

关键词： Jinchuan Ni-Cu-PGE deposit, Re-Os dating, ICP-MS.

New lower bounds of classical Ramsey numbers R(6,12., R(6,14) and R(6,15)

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chinese Science Bulletin 1998年第10期43卷 817-818页

作者： LUO Haipeng 1, SU Wenlong 2.and LI Qiao 3.1. Guangxi Academy of sciences, Nanning 53.03., china 2. Wuzhou First Middle {2., Wuzhou 543.02. china 3. Shanghai Jiaotong University, Shanghai 2.003., china Guangxi Academy of sciences Nanning China Wuzhou First Middle school Wuzhou China Shanghai Jiaotong University Shanghai China

Three new cyclic graphs are constructed by using a computer, and the lower bounds of three Ramsey numbers obtained: R(6,12.≥2.4, R(6,14)≥2.8,R(6,15)≥3.8, which fill in three blanks in the table of bounds of Ram... 详细信息

关键词： Ramsey number lower bound cyclic graph.

Statistical distribution of nonlinear random wave height

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Science china Earth sciences 2006年第4期49卷 443-448页

作者： HOU Yijun1, GUO Peifang1,2. SONG Guiting1,2. SONG Jinbao1, YIN Baoshu1 & ZHAO Xixi1,2.1. Institute of Oceanology, {3. Academy of sciences, Qingdao 2.6071,{2. 2. graduate University of the {3. Academy of sciences, Beijing 10003.,{2. Institute of Oceanology Chinese Academy of Sciences Qingdao China graduate University of the chinese Academy of {2. Beijing China

A statistical model of random wave is developed using Stokes wave theory of water wave dynamics. A new nonlinear probability distribution function of wave height is presented. The results indicate that wave steepness not only could be a parameter of the distribution function of wave height but also could reflect the degree of wave height distribution deviation from the Rayleigh distribution. The new wave height distribution overcomes the problem of Rayleigh distribution that the prediction of big wave is overestimated and the general wave is underestimated. The prediction of small probability wave height value of new distribution is also smaller than that of Rayleigh distribution. Wave height data taken from East china Normal University are used to verify the new distribution. The results in- dicate that the new distribution fits the measurements much better than the Rayleigh distribution.

关键词： Random ocean wave, nonlinearity, wave height distribution.

Synthesis of well-defined functional PE graft copoly-mers via ATRP process

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Science Bulletin 2005年第10期50卷 1048-1051页

作者： CAO Chengang1, 2. DONG Jinyong1 & HU Youliang1 1. CAS Key Laboratory of Engineering Plastics, Joint Laboratory of Polymer Science and Materials, Institute of Chemistry, chinese Academy of sciences, Beijing 100080,{2. 2. graduate school, chinese Academy of sciences, Beijing 10003., {2. CAS Key Laboratory of Engineering Plastics Joint Laboratory of Polymer Science and Materials Institute of Chemistry Chinese Academy of Sciences Beijing China graduate school Chinese Academy of Sciences Beijing China

In summary, we have demonstrated a convenient yet highly efficient method for the preparation of PE-based graft copolymers via ATRP. By introducing a small amount of styrene groups into PE chains via the selective copolymerization of ethylene with 1,4-divinylbenzene catalyzed by Et(Ind)2.rCl2.MAO, the multifunctional ATRP initiator of 1-chloroethylbenzene-containing PE was readily achieved by a quantitative hydrochlorination reaction and was shown to be very effective for the initiation of graft polymerization of MMA and styrene to prepare structurally well-defined PE-based graft copolymers.

关键词： ATRP Synthesis of well-defined functional PE graft copoly-mers via ATRP process PE well

Kinetics and reaction mechanism of phenol hydroxylation catalyzed by La-Cu_4FeAlCO_3

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Science china Chemistry 2005年第6期48卷 530-537页

作者： CHEN Chunxia1,2. XU Chenghua1, FENG Liangrong1, SUO Jishuan1 & QIU Fali1 1. Chengdu Institute of Organic Chemistry, chinese Academy of sciences, Chengdu 610041,{2. 2. graduate school of the chinese Academy of sciences, Beijing 10003.,{2. Chengdu Institute of Organic Chemistry Chinese Academy of Sciences Chengdu China graduate school of the {2. Academy of {3. Beijing China

The present work synthesizes La-Cu4FeAlCO3.catalyst under microwave irradiation and characterizes its structure using XRD and IR techniques. The results show that the obtained La-Cu4FeAlCO3.has a hydrotalcite structure. In the phenol hydroxylation with H2.2.catalyzed by La-Cu4FeAlCO3. the effects of reaction time and phenol/H2.2.molar ratio on the phenol hy-droxylation, and relationships between the initial hydroxylation rate with concentration of the catalyst, phenol, H2.2.and reaction temperature are also investigated in details. It is shown the phenol conversion can reach 50.09% (mol percent) in the phenol hydroxylation catalyzed by La-Cu4FeAlCO3. under the reaction conditions of the molar ratio of phenol/H2.2.1/2. the amount ratio of phenol/catalyst 2., reaction temperature 3.3.K, reaction time 12. min, 10 mL distilled water as solvent. Moreover, a kinetic equation of v = k[La ? Cu 4 FeAlCO 3.][C 6 H 5 OH][H 2.O 2.. and the activation energy of Ea=58.3. kJ/mol are obtained according to the kinetic studies. Due to the fact that the HO-Cu+-OH species are detected in La-Cu4FeAlCO3.H2.2.system by XPS, the new mechanism about the generation of hydroxyl free radicals in the phenol hydroxylation is pro-posed, which is supposed that HO-Cu+-OH species are transition state in this reaction.

关键词： rare earth, hydrotalcite, microwave irradiation, phenol hydroxylation, kinetics, reaction mechanism.

Mechanism and Defense on Malicious Code

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Wuhan University Journal of Natural sciences 2005年第1期10卷 83-88页

作者： WEN Wei-ping 1,2.3. QING Si-han 1,2.3.1. Institute of Software, the chinese Academy of {3., Beijing 100080,{2. 2.Engineering Research Center for Information Security Technology, the chinese Academy of {3., Beijing 100080,{2. 3.graduate school of the chinese Academy of {3., Beijing 100080,{2. Institute of Software the Chinese Academy of Sciences Beijing China Engineering Research Center for Information Security Technology the Chinese Academy of Sciences Beijing China graduate school of the {2. Academy of {3. Beijing China

With the explosive growth of network applications, the threat of the malicious code against network security becomes increasingly serious. In this paper we explore the mechanism of the malicious code by giving an attack model of the malicious code, and discuss the critical techniques of implementation and prevention against the malicious code. The remaining problems and emerging trends in this area are also addressed in the paper.

关键词： malicious code attacking model mechanism defense system security network security

De-interlacing technique based on total variation with spatial-temporal smoothness constraint

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Science in china(Series F) 2007年第4期50卷 561-575页

作者： YIN XueMin1,2.3. YUAN JianHua1,2. LU XiaoPeng1,2.& ZOU MouYan1,2.1 Institute of Electronics, chinese Academy of sciences, Beijing 100080,{2. 2.graduate school, chinese Academy of sciences, Beijing 10003.,{2. 3.Jiuquan Satellite Launch Center, Lanzhou 73.0}50,{2. Institute of Electronics Chinese Academy of Sciences Beijing China graduate school Chinese Academy of Sciences Beijing China Jiuquan Satellite Launch Center Lanzhou China

This paper introduces a new method of converting interlaced video to a progressively scanned video and image, The new method is derived from Bayesian framework with the spatial-temporal smoothness constraint and the MAP is done by minimizing the energy functional, The half-quadratic regularization method is used to solve the corresponding partial differential equations （PDEs）, This approach gives the improved results over the conventional de-interlacing methods, Two criteria are proposed in the paper, and they can be used to evaluate the performance of the de-interlacing algorithms,

关键词： video processing de-interlacing total variation spatio-temporai smoothness constraint PDEs half-quadratic regularization

Depside salts from Salvia miltiorrhiza improve myocardial microperfusion in rats using laser Doppler flowmetry

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Acta Pharmacologica Sinica 2007年第6期28卷 789-795页

作者： Xiao-fen LI~(2.3.,Yi-ping WANG~(2.4)~2.State Key Laboratory.of Drug Research,Shanghai Institute of Materia Medica,Shanghai Institutes for Biological {3.,chinese Academyof {3.,Shanghai 2.12.3.china,~3.graduate school of chinese Academy of {3.,Beijing 100049,china State Key Laboratory of Drug Research Shanghai Institute of Materia Medica Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai China graduate school of {2. Academy of {3. Beijing China

Aim:To investigate the effects of depside salts from Salvia miltiorrhiza on myo-cardial microperfusion and systemic hemodynamics in open-chest anaesthetizedSprague-Dawley ***:Myocardial microperfusion was measured bylaser Doppler flowmetry with a needle probe;cardiac output (CO) was determinedusing ultrasonic Doppler *** hemodynamic parameters,includingfemoral artery blood pressure,cardiac inotropy,and systemic vascular resistance(SVR) were simultaneously recorded by the PowerLab ***:Intrave-nous administration of S miltiorrhiza depside salts resulted in a significant imme-diate increase in CO and cardiac inotropy,but a fall in SVR.S miltiorrhiza depsidesalts (3. mg/kg and 60 mg/kg) promoted cardiac index (CI) by 12.2.±6.3. (P2..1%±3.5% (P3.±2.9% (P3. mg/kgand 60 mg/kg S miltiorrhiza depside salts,***:Theseresults indicated that S miltiorrhiza depside salts improved myocardial micro-perfusion,as well as CO.

关键词： lithospermate B myocardial microperfusion laser Doppler flowmetry cardiac output ultrasonic Doppler flowmetry