• 제목/요약/키워드: Light Region

검색결과 1,442건 처리시간 0.027초

Synthesis and Characterization of Blue Light-Emitting Polymers Containing Phenylenevinylene Units

  • 황도훈;강인남;장민식;심홍구
    • Bulletin of the Korean Chemical Society
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    • 제16권2호
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    • pp.135-138
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    • 1995
  • A series of new polymers containing phenylenevinylene (PV) units were synthesized by Wittig polycondensation reaction and properties of the synthesized polymers were characterized by FT-IR and UV-visible spectroscopy, and their light-emitting properties were studied. All of the synthesized polymers were soluble in organic solvents and showed good film quality. The absorption maxima and band edges of the polymers were moved to shorter wavelength region by reducing the electron donating alkoxy groups incorporated in phenylenevinylene unit. The photo-induced emission spectra were obtained and all of the polymers revealed their emission in blue region. The observed emission maxima of the polymers were ranged from 480-495 nm.

Disulfide Bond Bridged Divalent Antibody-Toxin, $(Fab-PE38fl)_2$ with the Toxin PE38 Fused to the Light Chain

  • Won, Jae-Seon;Choe, Mu-Hyeon
    • Journal of Microbiology and Biotechnology
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    • 제18권8호
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    • pp.1475-1481
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    • 2008
  • B3 antibody specifically binds the $Lewis^Y$-related carbohydrate antigen of many carcinomas, and it is used as a model antibody in this study. In a previous study, the Fab fragment of the antibody was fused to a 38 kDa truncated form of Pseudomonas exotoxin A, PE38, to make Fab-PE38, where PE38 is fused to the Fd fragment of the Fab domain. This parent monomer molecule, Fab-PE38, had no cysteine in the hinge region, and it could not make a disulfide bond to form a disulfide bond bridged homodimer. In this study, we constructed three different kinds of divalent Fab-toxin fusion homodimers where the toxin is fused to the light chain of Fab, $(Fab-PE38fl)_2$. In addition to the PE38 toxin fused to the light chain, these three molecules have different hinge sequences hi, h2, and h3 making Fabh1-, Fabh2-, and Fabh3-PE38fl monomers, respectively. These hinges contain only one cysteine on different positions of the hinge sequence. The disulfide bond between the hinge region of two monomers forms homodimers $(Fabh1-PE38fl)_2$, $(Fabh2-PE38fl)_2$, and $(Fabh3-PE38fl)_2$. The refolding yields of these dimers were 5-16-fold higher than a previously constructed dimer where the PE38 was fused to the Fd fragment $(Fabh2-PE38)_2$ [8]. Our data suggest that the steric repulsion between the two PE38s in $(Fabh1-PE38)_2$ during disulfide bridge formation is relieved by fusing it at the end of the light chain. The best cytotoxicity value of these dimers showed about 2.5-fold higher on an MCF7 cell line than that of the monovalent reference molecule in ng/ml scale, which is 15-fold higher in pM scale.

Doping Controlled Emitter with a Transparent Conductor for Crystalline Si Solar Cells

  • 김민건;김현엽;최우진;이준신;김준동
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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    • pp.590-590
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    • 2012
  • A transparent conducting oxide (TCO) layer was applied in crystalline Si (c-Si) solar cells without use of the conventional SiNx-coating. A high quality indium-tin-oxide (ITO) layer was directly deposited on an emitter layer of a Si wafer. Three different types of emitters were formed by controlling the phosphorous diffusion condition. A light-doped emitter forming a thinner emitter junction showed an improved photoconversion efficiency of 14.1% comparing to 13.2% of a heavy-doped emitter. This was induced by lower recombination within a narrower depletion region of the light-doped emitter. In the aspect of light management, the intermediate refractive index of ITO is effective to reduce the light reflection leading the enhanced carrier generation in a Si absorber. For the electrical aspect, the ITO layer serves as an efficient electrical conductor and thus relieves the burden of high contact resistance of the light-doped emitter. Additionally, the ITO works as a buffer layer of Ag and Si and certainly prevents the shunting problem of Ag penetration into Si emitter region. It discusses an efficient design scheme of TCO-embedded emitter Si solar cells.

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쥐오줌풀의 생육 및 뿌리수량에 미치는 광도와 온도의 영향 (Effects of Light Intensity and Temperature on Growth and Root Yield of Valeriana fauriei var. dasycarpa HARA)

  • 이종철;조장환;안대진;최영현
    • 한국약용작물학회지
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    • 제4권1호
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    • pp.7-11
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    • 1996
  • 쥐오줌풀의 재배법 구명을 위한 기초자료를 얻고자 광도 및 온도가 쥐오줌풀의 생육 및 근수량에 미치는 영향을 조사하였던 바 그결과는 다음과 같다. 1. 온도 및 광도와 쥐오줌풀 잎의 광합성간에는 고도로 유의한 2차곡선회귀가 인정되었으며, 이 회귀식에 의해 산출된 최대광합성을 위한 광도는 40,000Lux, 온도는 $17.7^{\circ}C$이었다. 2. 쥐오줌풀의 뿌리수량은 고냉지인 진부에서는 차광구에 비해 무차광구에서 증가하였으나 평야지인 음성에서는 오히려 차광구에서 증가되었다. 또한 지역간의 뿌리수량은 음성에서 보다는 진부에서 많았다. 3. 온도와 쥐오줌풀의 엽폭 및 근중간에는 각각 고도로 유의한 2차곡선회귀가 인정되었으며 이 회귀식에 의해 산출한 근생장(根生長)의 최적온도는 약 $20.3^{\circ}C$이었다.

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평면 이미지 기법을 이용한 분무 특성 해석 (The Spray Characterization Using Planar Imaging Technique)

  • 이경진;정기훈;윤영빈;정경석;정인석
    • 대한기계학회논문집B
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    • 제24권1호
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    • pp.93-101
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    • 2000
  • The characteristics of spray nozzle have been quantified with the measurement of fluorescence and Mie scattering images. To correct the attenuation of the incident light sheet, a sequential double-pass light sheet system and the geometrical averaging of two images was implemented. Quantitative mass flux distribution of spray was obtained from fluorescence image. 3-D image is reconstructed using 2-D radial images. Sauter mean diameter (SMD) distribution was determined using the ratio of fluorescence signal intensity and Mie scattering signal intensity and the values were quantified with PDP A data. The measurement of mass flux and SMD using planar imaging technique agee with PDP A data fairly well in the low density region. However, in dense region, there are significant errors caused by secondary scattering. It was found that the planar imaging technique provides many advantages over the point measurement technique, such as PDP A, and can be implemented for quantitative measurement, especially in low density region.

교류 구동 방법에 의한 유기전계발광소자 발광 특성의 모델 (Model of Organic Light Emitting Device Emission Characteristics with Alternating Current Driving Method)

  • 서정현;주성후
    • 한국재료학회지
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    • 제31권10호
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    • pp.586-591
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    • 2021
  • This paper proposes a mathematical model that can calculate the luminescence characteristics driven by alternating current (AC) power using the current-voltage-luminance (I-V-L) properties of organic light emitting devices (OLED) driven by direct current power. Fluorescent OLEDs are manufactured to verify the model, and I-V-L characteristics driven by DC and AC are measured. The current efficiency of DC driven OLED can be divided into three sections. Region 1 is a section where the recombination efficiency increases as the carrier reaches the emission layer in proportion to the increase of the DC voltage. Region 2 is a section in which the maximum luminous efficiency is stably maintained. Region 3 is a section where the luminous efficiency decreases due to excess carriers. Therefore, the fitting equation is derived by dividing the current density and luminance of the DC driven OLED into three regions, and the current density and luminance of the AC driven OLED are calculated from the fitting equation. As a result, the measured and calculated values of the AC driving I-V-L characteristics show deviations of 4.7% for current density, 2.9 % for luminance, and 1.9 % for luminous efficiency.

이동 로봇을 위한 3차원 거리 측정 장치기반 비포장 도로 인식 (3D Depth Measurement System-based Unpaved Trail Recognition for Mobile Robots)

  • 김성찬;김종만;김형석
    • 제어로봇시스템학회논문지
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    • 제12권4호
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    • pp.395-399
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    • 2006
  • A method to recognize unpaved road region using a 3D depth measurement system is proposed for mobile robots. For autonomous maneuvering of mobile robots, recognition of obstacles or recognition of road region is the essential task. In this paper, the 3D depth measurement system which is composed of a rotating mirror, a line laser and mono-camera is employed to detect depth, where the laser light is reflected by the mirror and projected to the scene objects whose locations are to be determined. The obtained depth information is converted into an image. Such depth images of the road region represent even and plane while that of off-road region is irregular or textured. Therefore, the problem falls into a texture identification problem. Road region is detected employing a simple spatial differentiation technique to detect the plain textured area. Identification results of the diverse situation of unpaved trail are included in this paper.

광산란 소멸법을 이용한 층류확산화염내에 매연입자의 크기 및 농도 측정 (Soot Size and Concentration Measurements in a Laminar Diffusion Flame Using a Lignt Scattering/Extinction Technique)

  • 하영철;김상수
    • 대한기계학회논문집
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    • 제16권9호
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    • pp.1796-1804
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    • 1992
  • 본 연구에서는 동심확산화염내에 생기는 매연 입자의 크기와 농도를 광산란 소멸법으로 보다 정확히 측정하여 궁극적 목적인 매연입자 제어의 기반을 조성하고자 한다.

THE DIFFUSE NEAR-INFRARED BACKGROUND SPECTRUM FROM AKARI

  • Kohji, Tsumura;Toshio, Matsumoto;Shuji, Matsuura;Itsuki, Sakon;Takehiko, Wada
    • 천문학논총
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    • 제32권1호
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    • pp.321-326
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    • 2017
  • We analyzed spectral data of the astrophysical diffuse emission obtained with the low-resolution spectroscopy mode on the AKARI InfraRed Camera (IRC) in the $1.8-5.3{\mu}m$ wavelength region. Advanced reduction methods specialized for slit spectroscopy of diffuse sky spectra have been developed, and a catalog of 278 spectra of the diffuse sky covering a wide range of Galactic and ecliptic latitudes was constructed. Using this catalog, two other major foreground components, the zodiacal light (ZL) and the diffuse Galactic light (DGL), were separated and subtracted by taking correlations with ZL brightness estimated by the DIRBE ZL model and with the $100{\mu}m$ dust thermal emission, respectively. The isotropic emission was interpreted as the extragalactic background light (EBL), which shows significant excess over the integrated light of galaxies at <$4{\mu}m$.

GAN-Based Local Lightness-Aware Enhancement Network for Underexposed Images

  • Chen, Yong;Huang, Meiyong;Liu, Huanlin;Zhang, Jinliang;Shao, Kaixin
    • Journal of Information Processing Systems
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    • 제18권4호
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    • pp.575-586
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    • 2022
  • Uneven light in real-world causes visual degradation for underexposed regions. For these regions, insufficient consideration during enhancement procedure will result in over-/under-exposure, loss of details and color distortion. Confronting such challenges, an unsupervised low-light image enhancement network is proposed in this paper based on the guidance of the unpaired low-/normal-light images. The key components in our network include super-resolution module (SRM), a GAN-based low-light image enhancement network (LLIEN), and denoising-scaling module (DSM). The SRM improves the resolution of the low-light input images before illumination enhancement. Such design philosophy improves the effectiveness of texture details preservation by operating in high-resolution space. Subsequently, local lightness attention module in LLIEN effectively distinguishes unevenly illuminated areas and puts emphasis on low-light areas, ensuring the spatial consistency of illumination for locally underexposed images. Then, multiple discriminators, i.e., global discriminator, local region discriminator, and color discriminator performs assessment from different perspectives to avoid over-/under-exposure and color distortion, which guides the network to generate images that in line with human aesthetic perception. Finally, the DSM performs noise removal and obtains high-quality enhanced images. Both qualitative and quantitative experiments demonstrate that our approach achieves favorable results, which indicates its superior capacity on illumination and texture details restoration.