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Ultrafast time-resolved probe of elementary steps in photo-luminescence of organic metal complexes and binding interaction with nucleic acids

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Ultrafast time-resolved probe of elementary steps in photo-l...

Ultrafast time-resolved study of model DNAs and binding interactions between DNA and metal complex

第一届全国光功能材料青年学者研讨会2018

作者： chensheng ma Wai-Ming Kwok Chi-Ming Che College of Chemistry and Environmental Engineering Shenzhen University Department of Applied Biology and Chemical Technology The Hong Kong Polytechnic UniversityHung Hom Department of Chemistry The University of Hong Kong

Photo-luminescent organic metal complexes have found diverse applications in areas such as sensor materials,OLEDs, and photo-catalysis, etc. To understand at molecular level the excited state dynamics of metal complex and how this may vary with the metal center, the ligand structure, and environmental factor is essential for rational design and better performance of metal complexes in the various applications. Herein we demonstrate utilization of a range of complementary ultrafast spectroscopy to investigate in real time the excited state dynamics for series of recently synthesized mono-, bi, and multi-nuclear transition metal complexes both in the solid state and in solution with solvent of varied properties. By direct probe of the excited state spectra and temporal evolution of the spectra, we are able to unravel the elementary steps underlying the entire dynamics of the excited state deactivation;the results unveil a number of remarkable features crucial for elucidating several key processes of photo-excited metal complexes. This involves the rate and timescale of the intersystem crossing,1-3 the molecular mechanism to delayed fluorescence for the multiple emission phenomenon,2,3 and the rapid events dictated by phase condition and solvent property for luminescence and photochemical outcomes of a prototype bi-nuclear gold complex.4 We also present result of time-resolved study on a tridentated Pt（II）complex exhibiting luminescence with energy and intensity highly sensitive to conformation of nucleic acids arising due to sequence specific intercalation binding interaction between the complex and the nucleic acids.5 Our work enriches knowledge on photo-physics and photochemistry of metal complexes, providing significant insights into the structure-property relationship for this important class of molecules.

关键词： luminescent metal complex,ultrafast spectroscopy excited state dynamics,dual emission DNA intercalation

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Ultrafast time-resolved study of model DNAs and binding inte...

Time-resolved Rresonance Raman Study of Hydroxyphenacyl Compounds

中国化学会第30届学术年会-第四十四分会：化学动力学

作者： chensheng ma Wai-Ming Kwok David.L.Phillips Chi-Ming Che College of Chemistry and Environmental Engineering Shenzhen University Department of Applied Biology and Chemical Technology The Hong Kong Polytechnic University Department of Chemistry The University of Hong Kong

Study of the excited states of nucleic acids has been undergoing a revival in recent years impelled largely by femtosecond time-resolved spectroscopy. The properties and dynamics of nucleic acid excited states play a pivotal role in controlling both the photostability and the propensity towards photodamage of the genetic material, which is crucial for understanding evolution of life and is also essential for public health. Binding interactions between nucleic acids and metal complex have on the other hand found broad applications in areas such as develop of anticancer drug and sensory material, etc. In this presentation, we will demonstrate ultrafast spectroscopic study which we integrated fs broadband time-resolved fluorescence with fs transient absorption to characterize directly excited states of A/T model DNAs as well as to explore bindings between an platinum complex with a series of selected model and natural DNAs and RNAs. The results we obtained for A/T DNAs show that the electronic nature, energy, and decay dynamics of excited states all vary significantly with the composition, sequence, and conformation of the oligomeric *** bindings between platinum complex and nucleic acids, manifested by the energy and lifetime of emission from the interacting systems, exhibit critical dependence on the content and sequence of the nucleic acids. In particular, it was found that the intercalation of the complex into A/T containing DNAs may give rise to a highly emissive adduct with abnormally low emission energy and unusually long emission lifetime rarely reported in the literature. These findings provide important insights for in-depth understanding of the nucleic acid excited states and binding interactions of metal complex with nucleic acids, which may have important ramification for improving the applications in related areas.

关键词： DNA excited states time-resolved fluorescence transient absorption metal complex DNA binding

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Time-resolved Rresonance Raman Study of Hydroxyphenacyl Comp...

第十三届全国光散射学术会议

作者： David Lee Phillips chensheng ma Wai Ming Kwok Wing Sum Chan Peng Zou The University of Hong Kong Department of Chemistry The University of Hong Kong

＜正＞Real-time monitoring of physiological responses in biological systems needs compounds called phototriggers that release the biological stimulant in a very fast and localized *** need for the fast and localized release of biological stimulants has driven the design and development of efficient phototngger *** p-hydroxyphenacyl（pHP）caged class of phototriggers was recently observed to undergo a

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空间太赫兹通信信道建模技术

应用激光 2024年第4期44卷 123-138页

作者：祃宸升何元智军事科学院系统工程研究院北京1000141

近年来,太赫兹频段成为下一代卫星通信频率拓展的重要方向。随着太赫兹器件的发展,空间太赫兹通信系统的研究与设计引起了许多研究人员的兴趣,而空间太赫兹通信信道建模是研究与设计空间太赫兹通信系统的基础。本文对空间太赫兹通信信... 详细信息

近年来,太赫兹频段成为下一代卫星通信频率拓展的重要方向。随着太赫兹器件的发展,空间太赫兹通信系统的研究与设计引起了许多研究人员的兴趣,而空间太赫兹通信信道建模是研究与设计空间太赫兹通信系统的基础。本文对空间太赫兹通信信道建模技术的相关研究进行综述。首先介绍空间太赫兹通信频段的传播特点;其次讨论空间太赫兹通信信道模型的分类以及不同场景下信道建模需要考虑的因素,回顾各个因素的研究进展;最后对目前的研究成果进行总结,同时对未来的研究方向进行展望,为未来太赫兹技术在卫星通信领域的应用提供理论依据。

关键词：太赫兹卫星通信传播特性信道建模

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某型增压器主轴断裂原因分析

柴油机 2021年第5期43卷 57-60页

作者：马辰生中车大连机车研究所有限公司辽宁大连116021

针对一起增压器主轴变截面处断裂故障,对主轴断口进行了宏观与微观分析。结果表明:主轴变截面处过渡圆角加工过小且形成尖锐交面,是导致主轴发生疲劳断裂的根本原因。通过改进主轴加工工艺,上述问题得到解决。

关键词：增压器主轴断裂加工

CH_4／Ni（111）化学吸附解离反应终态的理论研究

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吉林大学自然科学学报 1994年第1期 89-93页

作者：马晨生马理杨忠志吉林大学理论化学研究所

采用ＣＮＤＯ和ＡＳＥＤ－ＭＯ方法，选择Ｎｉ＿（１０）原子簇模拟Ｎｉ（１１１）晶面，分别对ＣＨ＿３／Ｎｉ（１１１）和Ｎ／Ｎｉ（１１１）吸附体系进行了研究，所得结论与实验基本一致。

关键词：甲烷化学吸附反应终态镍

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某型增压器导风轮叶片断裂失效分析

铁道机车与动车 2021年第6期 41-43,I0004页

作者：马辰生赵理志大连中车泽通机械有限公司辽宁大连116021 中交烟台环保疏浚有限公司山东烟台264004

针对某型增压器运用18万km发生叶片断裂失效故障,对导风轮叶片进行断口形貌观察、化学成分测定及强度校核计算分析失效原因。结果表明:导风轮毛坯锻造变形不足,未能将硬质相充分击碎分散,降低了材料的疲劳寿命。叶轮高速旋转离心力作用... 详细信息

针对某型增压器运用18万km发生叶片断裂失效故障,对导风轮叶片进行断口形貌观察、化学成分测定及强度校核计算分析失效原因。结果表明:导风轮毛坯锻造变形不足,未能将硬质相充分击碎分散,降低了材料的疲劳寿命。叶轮高速旋转离心力作用下,在导风轮叶片的进气边硬质相聚集区萌生了疲劳裂纹并扩展,最终导致叶片断裂。提出了相应的改进措施。

关键词：导风轮叶片失效应力

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高压比增压器转子轴承系统振动性能改进

柴油机 2020年第3期42卷 48-52页

作者：刘淑华马辰生刘志坚中车大连机车研究所有限公司辽宁大连116021

针对我国铁路运用的大功率交流传动内燃机车研发了一款新型增压器,其压比和流量较现有产品大幅提高;由于压气机叶轮线速度和转子质量提高,现有的叶轮与主轴的连接方式不能满足新研发增压器的要求,研发了一种新型的压气机叶轮与主轴连接... 详细信息

针对我国铁路运用的大功率交流传动内燃机车研发了一款新型增压器,其压比和流量较现有产品大幅提高;由于压气机叶轮线速度和转子质量提高,现有的叶轮与主轴的连接方式不能满足新研发增压器的要求,研发了一种新型的压气机叶轮与主轴连接方式,并设计了新型轴承。对改进前后的转子轴承系统进行了临界转速、稳定性、瞬态响应和转子轴心轨迹分析,并进行试验测试,验证了新转子轴承系统完全达到要求。目前,改进转子结构后的增压器已经完成了平台型式试验、装车运用考核试验,实现批产。

关键词：涡轮增压器压气机叶轮轴承轴心轨迹

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网络构成大气湍流遥测系统

电子测量技术 2000年第2期23卷 6-8页

作者：肖黎明刘小勤马成胜曾宗泳中国科学院安徽光学精密机械研究所

文中介绍的遥测系统由微机承担主站监控,对终端站实行控制,处理数据,计算并实时显示。单片机构成智能终端站。终端站完成对其所处现场的数据采集和预处理。构成的遥测系统用于500米大气传输光路上的湍流强度分布以及湍流谱的测量。它具... 详细信息

文中介绍的遥测系统由微机承担主站监控,对终端站实行控制,处理数据,计算并实时显示。单片机构成智能终端站。终端站完成对其所处现场的数据采集和预处理。构成的遥测系统用于500米大气传输光路上的湍流强度分布以及湍流谱的测量。它具有自动采集、处理、储存、实时显示等功能,结构紧凑、使用可靠等优点,可得到复杂地形的大气湍流强度分布。

关键词：微机单片机湍流测量遥测系统数据采集