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Hydrogen Bonding Effects on the Photophysical Properties of 2,3-dihydro-3-keto- 1H-pyrido[3,2,1-kl] phenothiazine

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Chinese Journal of Chemical Physics 2012年第3期25卷 254-260,373页

作者： Song-qiu yang Guo-zhong He State Key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical Physics ChineseAcademy of Sciences Dalian 115023 China Graduate School of the Chinese Academy of Sciences Beijing 100039 China

Time-dependent density functional theory （TDDFT） and femtosecond transient absorption spectroscopy were used to investigate the photophysical properties of 2,3-dihydro-3-keto-lH- pyrido[3,2,1-kl]phenothiazine （PTZ4） and 3-keto-lH-pyrido[3,2,1-kl]phenothiazine （PTZ5）. The calculated results obtained from TDDFT suggest that the red-shifts of the absorption spectra of these two fluorophores in methanol are due to the formation of hydrogen-bonded complexes at the ground state. Four conformers of PTZ4 were obtained by TDDFT. The two fluorescence peaks of PTZ4 in tetrahydrofuran （THF） came from the ICT states of the four conformers. The fluorescence of PTZ4 in THF showed a dependence on the excitation wavelength because of butterfly bending. The excited state dynamics of PTZ4 in THF and methanol were obtained by transient absorption spectroscopy. The lifetime of the excited PTZ4 in methanol was 53.8 ps, and its relaxation from the LE state to the ICT state was completed within several picoseconds. The short lifetime of excited PTZ4 in methanol was due to the formation of out-of-plane model hydrogen bonds between PTZ4 and methanol at the excited state.

关键词： 2,3-dihydro-3-keto-lH-pyrido[3,2,1-kl]phenothiazine Time-dependent densityfunctional theory Femtosecond transient absorption spectroscopy Hydrogen bonding effect

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降香黄檀混交林土壤微生物分布特征

福建林业科技 2016年第3期43卷 128-132页

作者：陈彧杨众养周国英刘君昂黄馨海南省林业科学研究所海南海口571100 中南林业科技大学林学院湖南长沙410004

采用稀释涂布平板培养法,分析比较5种降香黄檀混交林(降香黄檀+檀香、降香黄檀+母生、降香黄檀+火焰木、降香黄檀+沉香、降香黄檀+奥式黄檀)及纯林土壤微生物分布特征。结果表明:各土壤类型微生物数量存在差异,微生物总数以降香黄檀+檀... 详细信息

采用稀释涂布平板培养法,分析比较5种降香黄檀混交林(降香黄檀+檀香、降香黄檀+母生、降香黄檀+火焰木、降香黄檀+沉香、降香黄檀+奥式黄檀)及纯林土壤微生物分布特征。结果表明:各土壤类型微生物数量存在差异,微生物总数以降香黄檀+檀香混交林最多,达112.36×104cfu·g^(-1),混交林的土壤微生物总数均显著高于纯林;各类型微生物数量具有明显的垂直变化规律,即土壤微生物主要集中在0~20 cm土层,随土层加深,微生物数量逐渐下降。各类型土壤微生物数量均表现为细菌>放线菌>真菌,土壤细菌数量以降香黄檀+檀香混交林最多,为104.27×104cfu·g^(-1);土壤放线菌数量、土壤真菌数量均以降香黄檀+母生混交林最多,分别为68.68×103cfu·g^(-1)、22.03×103cfu·g^(-1)。

关键词：降香黄檀土壤微生物混交林纯林

A video conferencing system based on SDN-enabled SVC multicast

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Frontiers of Information Technology & Electronic Engineering 2016年第7期17卷 672-681页

作者： En-zhong yang Lin-kai ZHANG Zhen YAO Jian yang School of Information Science and Technology University of Science and Technology of China

Current typical video conferencing connection is bridged by a multipoint control unit(MCU),which may cause large delay and communication bottleneck for the whole *** the development of network technology,a video conferencing system can be implemented based on software-defined networking(SDN),which makes the service controllable and improves the scalability and ***,a video encoding method called scalable video coding(SVC) can also *** this paper,we propose a video conferencing architecture based on SDN-enabled SVC multicasting,which discards the traditional Internet group management protocol(IGMP) and *** system implements SVC multicast streaming to satisfy different device capabilities of various conference *** SDN controller is responsible for dynamically managing and controlling the layers of a video stream when a conference member faces network ***,a conference manager is designed to facilitate the management of the conference *** results show that our system can not only provide a flexible and controllable video delivery,but also reduce the network usage while guaranteeing the quality of service(QoS) of video conferencing.

关键词： Software-defined networking(SDN) Multicast Scalable video coding Video conferencing system

Longitudinal dispersive coefficient in channels with aquatic vegetation:A review

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Journal of Hydrodynamics 2023年第3期35卷 379-395页

作者： Liu yang Hao-ze Fang zhong-hua yang Wen-xin Huai State Key Laboratory of Water Resources Engineering and Management Wuhan University Wuhan China

The determination of longitudinal dispersion coefficient in rivers is necessary for pollution control,environmental risk assessment,and *** rivers with aquatic vegetation,the flow field is remarkably modified by canopies,which affects velocity profiles and dispersion characteristics dominated by the heterogeneity of the velocity *** dispersion is deduced from lateral and vertical longitudinal velocity gradients for compound channels with vegetated floodplains and rectangular channels with river-wide vegetation,*** many efforts have been exerted to clarify the dispersion process in different conditions and predict the diffusion of contaminants in vegetated rivers,no studies have introduced it *** study reviews the dispersion coefficient characteristics,including magnitude,main impacted factors,and relationships with flow and vegetation features,in channels with aquatic canopies considering the variation of impact factors changing with the different vegetation and river morphology *** typical methodologies for determining longitudinal dispersion coefficients are also summarized to understand the dispersion processes and *** from the pioneer outcomes of previous studies,the review also emphasizes the deficiency of existing studies and suggests possible future directions for improving the theory of dispersion in vegetated channels.

关键词： Vegetated flows longitudinal dispersion coefficient spatial heterogeneity

The finite-time ruin probability in the presence of Sarmanov dependent financial and insurance risks

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Applied Mathematics(A Journal of Chinese Universities) 2014年第2期29卷 194-204页

作者： yang yang LIN Jin-guan TAN zhong-quan School of Mathematics and Statistics Nanjing Audit University School of Economics and Management Southeast University Department of Mathematics Southeast University College of Mathematics Physics and Information Engineering Jiaxing University

Consider a discrete-time insurance risk model. Within period i, i≥ 1, Xi and Yi denote the net insurance loss and the stochastic discount factor of an insurer, respectively. Assume that {（Xi, Yi）, i≥1） form a sequence of independent and identically distributed random vectors following a common bivariate Sarmanov distribution. In the presence of heavy-tailed net insurance losses, an asymptotic formula is derived for the finite-time ruin probability.

关键词： Asymptotics long-tailed and dominatedly-varying-tailed distribution financial and insurancerisks finite-time ruin probability bivariate Sarmanov distribution.

Dark Localized Waves in Shallow Waters:Analysis within an Extended Boussinesq System

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Chinese Physics Letters 2024年第4期41卷 32-37页

作者： Zhengping yang Wei-Ping zhong Milivoj Belic Department of Medical Science Shunde PolytechnicShunde 528300China Department of Electronic Engineering Shunde PolytechnicShunde 528300China Division of Arts and Sciences Texas A&M University at Qatar23874 DohaQatar

We study dark localized waves within a nonlinear system based on the Boussinesq approximation,describing the dynamics of shallow water *** symbolic calculus,we apply the Hirota bilinear method to transform an extended Boussinesq system into a bilinear form,and then use the multiple rogue wave method to obtain its dark rational *** the first-and second-order dark solutions,we examine the conditions under which these localized solutions exist and their spatiotemporal *** the selection of various parameters and by utilizing different visualization techniques(intensity distributions and contour plots),we explore the dynamical properties of dark solutions found:in particular,the first-and second-order dark rogue *** also explore the methods of their *** findings presented here not only deepen the understanding of physical phenomena described by the(1+1)-dimensional Boussinesq equation,but also expand avenues for further *** method can be extended to other nonlinear systems,to conceivably obtain higher-order dark rogue waves.

关键词： Boussinesq bilinear nonlinear

Robust Iterative Learning Control of Single-phase Grid-connected Inverter

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International Journal of Automation and computing 2014年第4期11卷 404-411页

作者： zhong-Qiang Wu Chun-Hua Xu yang yang Key Lab of Industrial Computer Control Engineering of Hebei Province Yanshan University

For the single phase inductance-capacitance-inductance(LCL) grid-connected inverter in micro-grid, a kind of robust iterative learning controller is designed. Based on the output power droop characteristics of inverter, the current sharing among the inverters is achieved. Iterative learning strategy is suitable for repeated tracking control and inhibiting periodic disturbance, and is designed using robust performance index, so that it has the ability to overcome the uncertainty of system parameters. Compared with the repetitive control, the robust iterative learning control can get high precision output waveform, and enhance the tracking ability for waveform, and the distortion problem of the output signal can be solved effectively.

关键词： Inductance-capacitance-inductance (LCL) filter iterative learning robust control power droop-characteristics repetitive control

Metal-organic frameworks with dinuclear metal centers for synergistically boosting CO2 photoreduction

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Science China Chemistry 2025年第1期 201-208页

作者： Hui-Feng Wang Wen-Jie Shi Yu-Xin yang Bao-Xia Dong Tong-Bu Lu Di-Chang zhong School of Chemistry and Chemical Engineering Yangzhou University Institute for New Energy Materials and Low Carbon Technologies School of Materials Science and Engineering Tianjin University of Technology

Dinuclear metal synergistic catalysis （DMSC） has been proved powerful in boosting CO2reduction,while this has not been achieved in heterogeneous catalysts with long-range order *** this study,we,by introduction of metal catalytic centers into an indium-based metal-organic framework （MOF）,obtained a series of isostructural In-MOFs,including three MOFs with mononuclear metal catalytic center （M-In）,three MOFs with dinuclear homometallic catalytic centers （MM-In）,and three MOFs with dinuclear heterometallic catalytic centers (MM’-In,M/M’=Co（II）,Ni（II）,Zn（II）).It was found that all these MOFs can serve as catalysts for photochemical CO2reduction to *** with M-In,the catalytic activities of MM-In were obviously enhanced,and that of MM’-In was further significantly *** example,the CO yield of Co Zn-In reaches a record value of 12,700μmol g-1h-1,which is 4.0,8.1,9.4,and 18.6-fold higher than that of Co Co-In,Zn Zn-In,Co-In,and Zn-In,***,the catalytic activities of Co Ni-In and Ni Zn-In also show different fold increase than those of corresponding dinuclear homometallic and mononuclear metallic *** results of control experiments and theoretical calculation reveal that the higher catalytic activities of MM-In over M-In can be ascribed to the DMSC effect,and the higher catalytic activity of MM’-In over MM-In can be ascribed to the strengthened DMSC *** work reveals the relationship between DMSC effect and bimetal centers in CO2reduction,which provides new insights into the DMSC and paves a new way to design highly active catalysts for photochemical CO2reduction.

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Influence of the Coulomb exchange term on nuclear single-proton resonances

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Nuclear Science and Techniques 2016年第5期27卷 231-237页

作者： Shu-yang Wang zhong-Lai Zhu zhong-Ming Niu School of Physics and Materials Science Anhui University

Nuclear single-proton resonances are sensitive to the Coulomb field,while the exchange term of Coulomb field is usually neglected due to its *** combining the complex scaling method with the relativistic mean-field model,the influence of the Coulomb exchange term on the single-proton resonances is investigated by taking Sn isotopes and N=82 isotones as *** is found that the Coulomb exchange term reduces the singleproton resonance energy within the range of 0.4-0.6 MeV and leads to similar isotopic and isotonic trends of the resonance energy as those without the Coulomb exchange ***,the single-proton resonance width is also reduced by the Coulomb exchange term,whose influence generally decreases with the increasing neutron number and increases with the increasing proton ***,the influence of the Coulomb exchange term cannot change the trend of the resonance width with respect to the neutron number and proton ***,the influence of the Coulomb exchange term on the resonance width is investigated for the doubly magic nuclei ^(40)Ca,^(56,78)Ni,^(100,132)Sn,and ^(208)*** is found that the Coulomb exchange term reduces the proton resonance width within 0.2 MeV,whose magnitude depends on the specific nucleus and the quantum numbers of resonant states.

关键词：共振能量库仑场交换项质子数相对论平均场模型共振宽度中子数非定域性