• 제목/요약/키워드: Time Resolved

검색결과 905건 처리시간 0.037초

Influence of frequency and Sustain Voltage on Time-Resolved Discharge Images

  • 김순배
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2000년도 제18회 학술발표회 논문개요집
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    • pp.204-204
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    • 2000
  • AC-PDP로부터 방출된 빛의 방전 현상을 이해하고자 시간-공간상으로 분해된 방전이미지를 유지방전시 진동수와 유지방전전압에 따라 조사하였다. 방전이미지는 방전전류가 최대인 지점에서 최대 밝기를 가지며 전류량이 많을수록 향상됨을 볼 수 있었다. 사용된 패널은 전극폭 260umm, 전극간격 100um, 격벽높이 120um, 기압은 400Torr로 Ne-Xe(4%) 가스를 사용하였다. 실험조건은 진동수 50KHz, 100KHz, 150KHz와 유지방전전압 170V, 180V, 190V, 200V에 따른 방전이미지의 변화된 형태를 고찰하였다.

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Photodecomposition Mechanism of 2-Methoxy-1,2-diphenyl Diazoethane

  • 성대동;임귀택;김민식;박동규
    • Bulletin of the Korean Chemical Society
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    • 제16권1호
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    • pp.47-52
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    • 1995
  • The mechanism of the photodecomposition of 2-methoxy-1,2-diphenyl diazoethane has been investigated in methanol and isoprene using time-resolved laser flash photolysis techniques. The reaction of triplet carbene which is generated from 2-methoxy-1,2-diphenyl diazoethane with methanol is believed to proceed via thermal excitation to the singlet state. The activation energy and enthalpy are consistent with a mechanism involving thermal equilibrium between the triplet and singlet state followed by the reaction of the singlet with methanol to give ether.

Reaction between CH₃and H₂at Conbustion Temperatures

  • 백현주;신관수;Yang, H.;V. Lissianski;W. C. Gardiner, Jr.
    • Bulletin of the Korean Chemical Society
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    • 제16권6호
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    • pp.543-546
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    • 1995
  • The reaction between CH3 radicals and H2 was investigated behind incident shock waves at temperatures between 1308 and 1825 K by following the consumption of CH3 using a time resolved UV absorption method at 213.9 nm. The rate coefficient expression 1.10 X 1013 exp(-7370 K/T) cm3mol-1s-1 for the reaction of CH3 with H2 was derived.

Investigation of Molecular Coupling Effects on Photothermal Properties of Polar Solutions by Thermal Lens

  • 하정현;임종태;최중길;김용록
    • Bulletin of the Korean Chemical Society
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    • 제17권8호
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    • pp.682-685
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    • 1996
  • Photothermal properties depend on the characteristics of energy transfer processes in solution. In this study, a time-resolved single beam thermal lens experiment in various solvents is employed to investigate the energy coupling effects which govern the energy transfer processes. Interestingly, it is observed that the behaviour of the photothermal propagation in solution depends on the property of solution and the concentration of solute in a single beam thermal lens configuration. These characteristics lead us to consider the solute-solvent coupling effects as well as the solvent-solvent interactions.

Picosecond Protein Fluorescence and Time-Resolved $Eu^{3+}$ Luminescence Spectroscopic Studies on the Roles of $Ca^{2+}$ in Subtilisin Carlsberg

  • Lee, Sunbae;Jang, Du-Jeon
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 1997년도 학술발표회
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    • pp.44-44
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    • 1997
  • Ca$^{2+}$ is one of the most common metal ions associated with proteins, playing more or less well-defined functional roles in biological activities. In protease, the presence of $Ca^{2+}$ slows down autolysis and enhances thermal stability. Subtilisin, one of the best studied proteases, is known to have two $Ca^{2+}$ -binding sites.(omitted)

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극초단 펄스레이저의 분광학 응용 (Spectroscopic Applications of Ultrashort Pulse Lasers)

  • 김동호
    • 한국광학회지
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    • 제1권1호
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    • pp.87-97
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    • 1990
  • With the recent advent of various ultrashort pulse lasers, time-resolved laser spectroscopic techniques have been widely recognized as versatile tools to study ultrafast phenomena in many research areas. These techniques are currently being employed not only to study atomic and molecular physics but to characterize the excited state or the carrier dynamics on surfaces of semiconductors, metals and thin layer materials. Also the sweetching speed measurement of ultrafast electro-optic devices using ultrashort laser pulses becomes important in high-speed electronics. Here, some principles of spectroscopic techniques with ps or fs lasers and their applications are summarized briefly.

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Development of a dual-mode energy-resolved neutron imaging detector: High spatial resolution and large field of view

  • Wenqin Yang;Jianrong Zhou;Jianqing Yang;Xingfen Jiang;Jinhao Tan;Lin Zhu;Xiaojuan Zhou;Yuanguang Xia;Li Yu;Xiuku Wang;Haiyun Teng;Jiajie Li;Yongxiang Qiu;Peixun Shen;Songlin Wang;Yadong Wei;Yushou Song;Jian Zhuang;Yubin Zhao;Junrong Zhang;Zhijia Sun;Yuanbo Chen
    • Nuclear Engineering and Technology
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    • 제56권7호
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    • pp.2799-2805
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    • 2024
  • Energy-resolved neutron imaging is an effective way to investigate the internal structure and residual stress of materials. Different sample sizes have varying requirements for the detector's imaging field of view (FOV) and spatial resolution. Therefore, a dual-mode energy-resolved neutron imaging detector was developed, which mainly consisted of a neutron scintillator screen, a mirror, imaging lenses, and a time-stamping optical fast camera. This detector could operate in a large FOV mode or a high spatial resolution mode. To evaluate the performance of the detector, the neutron wavelength spectra and the multiple spatial resolution tests were conducted at CSNS. The results demonstrated that the detector accurately measured the neutron wavelength spectra selected by a bandwidth chopper. The best spatial resolution was about 20 ㎛ in high spatial resolution mode after event reconstruction, and a FOV of 45.0 mm × 45.0 mm was obtained in large FOV mode. The feasibility was validated to change the spatial resolution and FOV by replacing the scintillator screen and adjusting the lens magnification.

Numerical study of dynamic buckling for plate and shell structures

  • Liu, Z.S.;Lee, H.P.;Lu, C.
    • Structural Engineering and Mechanics
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    • 제20권2호
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    • pp.241-257
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    • 2005
  • A numerical approach combining the finite element method with two different stability criteria namely the Budiansky and the phase-plane buckling criteria is used to study the dynamic buckling phenomena of plate and shell structures subjected to sudden applied loading. In the finite element analysis an explicit time integration scheme is used and the two criteria are implemented in the Finite Element analysis. The dynamic responses of the plate and shell structures have been investigated for different values of the plate and shell imperfection factors. The results indicate that the dynamic buckling time, which is normally considered in predicting elasto-plastic buckling behavior, should be taken into consideration with the buckling criteria for elastic buckling analysis of plate and shell structures. By selecting proper control variables and incorporating them with two dynamic buckling criteria, the unique dynamic buckling load can be obtained and the problems of ambiguity and contradiction of dynamic buckling load of plate and shell structure can be resolved.