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검색결과 163건 처리시간 0.025초

25,27-Bis(1-propyloxy)calix[4]arene-26,28-[(5',6')(14',15')-dibenzo]crown-7, $C_{54}H_{58}O_9$

  • Kim, Jong-Seung;Kim, Moon-Jib;Lee, Jin-Ho;Kim, Jin-Gyu;Suh, Il-Hwan
    • 한국결정학회지
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    • 제10권1호
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    • pp.28-32
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    • 1999
  • The title compound consisting of a calix[4]arene molecule with four phenyl rings arranged alternately in anti-orientation fashion, two propyloxy groups attached on the upper rim of calix[4]arene, and polyther chain with two phyenyl rings attached on the lower rim of calix[4]arene offers a big cavity inside a molecule with might a potential for forming host-guest complexes.

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N-Tosyl Calix[4]arene Azacrown Ether, $C_{45}H_{49}NO_6S$

  • Kim, Jong-Seung;Kim, Moon-Jib;Choo, Geum-Hong;Lee, Jin-Ho;Suh, Il-Hwan
    • 한국결정학회지
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    • 제10권1호
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    • pp.66-70
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    • 1999
  • The calix[4]arene molecule adopting the 1,3-alternate conformation forms a square cavity, and two pair phenyl rings lying above and below a least-square plane defined by the four bridging methylene groups in the calix[4]arene are widened upwards and downwards, respectively, from central axis, which leads to O1-O4=4.064 and O2-O3=3.864 . Two propyloxy groups are stabilized with all trans conformations, but the rather short azacrown ether chain with two oxygen atoms includes cis/trans conformations with O1-C35=2.906 . Therefore the cavity does not seem to be big enough to form a host-guest complex.

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Lightweight Intrusion Detection of Rootkit with VMI-Based Driver Separation Mechanism

  • Cui, Chaoyuan;Wu, Yun;Li, Yonggang;Sun, Bingyu
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제11권3호
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    • pp.1722-1741
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    • 2017
  • Intrusion detection techniques based on virtual machine introspection (VMI) provide high temper-resistance in comparison with traditional in-host anti-virus tools. However, the presence of semantic gap also leads to the performance and compatibility problems. In order to map raw bits of hardware to meaningful information of virtual machine, detailed knowledge of different guest OS is required. In this work, we present VDSM, a lightweight and general approach based on driver separation mechanism: divide semantic view reconstruction into online driver of view generation and offline driver of semantics extraction. We have developed a prototype of VDSM and used it to do intrusion detection on 13 operation systems. The evaluation results show VDSM is effective and practical with a small performance overhead.

Nanoparticles-induced Alignment in Liquid Crystal Cells

  • Jeng, Shie-Chang;Kuo, Chia-Wei;Lin, Yan-Rung;Wang, Hsing-Lung;Liao, Chi-Chang;Yang, Chen-Yu;Hwang, Shug-June
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.1077-1079
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    • 2008
  • Nanoparticles-induced vertical alignment (NIVA) in the liquid crystal (LC) devices was observed and has been applied successfully on fabricating the hybrid-aligned nematic LC cells and guest-host LC cells. In this talk, we will discuss the characteristics of the electric and optical properties of NIVA-LC cells with different dopant concentrations and demonstrate that nanoparticles can be spin-coated on the substrate at a low temperature.

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Bowl-형 Halloysite를 Host 격자로 한 새로운 Intercalation 화합물(I) (화학반응성에 따른 Nagano-Halloysite의 특성화 연구) (Neue Schichteinlargerungsverbindungen des schalenfoermigen Halloysits als Wirtsgitter (I) (Chemische Charakterisierung des japanisohen Nagano-Halloysits durch Intercalationsreaktionen))

  • 최진호;아민바이스
    • 한국세라믹학회지
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    • 제19권3호
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    • pp.199-204
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    • 1982
  • Bowl 형태의 일본산 Nagano 점토에 대한 분류 및 특성화 연구를 하였다. 결정입자 크기를 1$\mu$ 이하로 침강분리 시킨후 전자현미경으로 결정형태를 관찰하였다. 아울러 결정형태, 구조적 결함 및 intercalation 반응성의 상호관계를 검토하기 위하여 tube 형태의 한국산 halloysite 및 plate 형태의 kaolinite를 비교 조사하였다. 특이한 Bowl 형 Nagano 점토는 tube형 halloysite와 화학 반응성에서 동일하여 극성 내지는 hydrogen bridge 결합을 하는 guest 분자와 반응하여 층간삽입 화합물을 형성 하였다. 화학반응성에 따른 점토분류방법에 의해 Nagano 점토가 halloysite임을 밝혔으며 아울러 결정의 형태는 반응성에 영향을 미치지 않음을 알 수 있었다.

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투명 금속 음극을 이용한 녹색 인광 OLED의 특성 (Characteristic of transparent OLED using transparent metal cathode with green phosphorescent dopant)

  • 윤도열;문대규
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2010년도 하계학술대회 논문집
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    • pp.154-154
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    • 2010
  • We have developed transparent OLED with green phosphorescent doped layer using transparent metal cathode deposited by thermal evaporation technique. Phosphorescent guest molecule, $Ir(ppy)_3$, was doped in host mCP for the green phosphorescent emission. Ca/Ag double layers were used as a cathode material of transparent OLED. The turn-on voltage of OLED was 5.2 V. The highest efficiency of the device reachs to 31 cd/A at 2 mA/$cm^2$.

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플라스틱 기판을 이용한 고분자 청색 유기발광다이오드의 발광 특성 (Emission Characteristics of Polymer Blue Organic Light Emitting Devices on the Plastic Substrates)

  • 정재훈;문대규
    • 한국전기전자재료학회논문지
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    • 제26권9호
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    • pp.682-685
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    • 2013
  • We have fabricated blue phosphorescent organic light-emitting devices (OLEDs) on a plastic substrate. The solution coated poly (9-vinylcarbazole) (PVK) host doped with Bis (3,5-difluoro-2-(2-pyridyl)phenyl_(2-carboxypyridyl)irdium(III) (FIrPic) guest molecules was used as an hole transporting emission layer. The device structure was ITO/PVK:FIrpic (50 nm, xwt%)/TAZ 50 nm)/LiF (0.5 nm)/Al (100 nm). The concentration of FIrpic molecule was varied from 1 wt% to 10 wt%. The OLED on plastic substrate exhibited maximum current efficiency of 18 cd/A with 5 wt% FIrpic molecules were doped into the PVK layer.

다공성 매질 내에서 메탄 하이드레이트의 분해에 의한 2 상 유동 해석 (Simulation of Two Phase Flow in Porous Media After Disso of Methane Hydrates)

  • 장동근;김남진;이재용;김종보
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 추계학술대회논문집B
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    • pp.241-246
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    • 2000
  • Gas hydrates are solid solutions when water molecules are linked through hydrogen bondin create host lattice cavities that can enclose a large variety of guest gas molecules. The natural hydrate crystal may exist at low temperature above the normal freezing point of water and pressure greater than about 30 bars. A lot of quantities of natural gas hydrates exists in the ear many production schemes are being studied. In the present investigation, depressurization method considered to predict the production of gas and the simulation of the two phase flow - gas and - in porous media is being carried out. The simulation show about the fluid flow in porous have a variety of applications in industry. Results provide the appearance of gas and water prod the pressure profile, the saturation of gas/ water/ hydrates profiles and the location of the pl front.

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올레핀 저장/회수 기술 응용을 위한 하이드로퀴논 크러스레이트의 분광학적 분석 연구 (Spectroscopic Analysis on Hydroquinone Clathrates for an Application to Storage/Recovery of Olefin Compounds)

  • 이종원;도뗄 쁘라틱;강성필
    • 한국수소및신에너지학회논문집
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    • 제24권5호
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    • pp.437-443
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    • 2013
  • Clathrate samples, using hydroquinone as a host and ethylene or propylene as a possible guest, were prepared and analyzed by means of spectroscopic measurements. Obtained results showed that ethylene can form clathrate compounds with hydroquinone at 4.0MPa and room temperature, while propylene cannot form clathrate compounds. Different formation behaviors of these two olefin compounds can be applied to a clathrate-based storage/recovery of ethylene in a selective way, and can provide useful information on the cavity size of the formed clathrate compounds.

Macroscopic Nonlinear Optical Properties of Tricyanopyrrolidene Chromophore Containing Amorphous Polycarbonate: Effect of Molecular Lateral Moiety in the Conjugative Structure

  • Cho, Min-Ju;Lee, Sang-Kyu;Jin, Jung-Il;Choi, Dong-Hoon
    • Macromolecular Research
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    • 제14권6호
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    • pp.603-609
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    • 2006
  • Tricyanopyrrolidene chromophores were prepared in order to compare their macroscopic nonlinear optical (NLO) properties with a conjugated structure through the long molecular axis. A thiophene or phenyl ring was tethered to an ethylenic bond; it may act as a lateral moiety to disrupt the planarity of a chromophore and lessen the electrostatic interaction. Thin film composites of these chromophores dissolved in amorphous polycarbonate (APC) were fabricated. Real time pole and probe method was employed to investigate the change of electro-optic (EO) signal during poling. The EO properties and their relaxation behaviors of the guest-host systems containing newly synthesized chromophores were investigated in detail.