• 제목/요약/키워드: nanometer

검색결과 595건 처리시간 0.032초

Studies on Reversed Micellar Membranes for Biotechnology in Japan

  • Furusaki, Shintaro
    • 한국막학회:학술대회논문집
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    • 한국막학회 2004년도 Proceedings of the second conference of aseanian membrane society
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    • pp.7-10
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    • 2004
  • Reversed micelles (RMs) are nanometer-scale molecular assemblies in organic media. Their surface films (membranes) are composed of surfactant molecules normally holding two hydrocarbon hydrophobic chains. Di-2-ethylhexyl sulfosuccinate (AOT), which is a negatively charged molecule, is most popular surfactant utilized to form reversed micelles.(omitted)

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Enhancement of the surface plasmon-polariton excitation in nanometer metal films

  • Kukushkin, Vladimir A.;Baidus, Nikoly V.
    • Advances in nano research
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    • 제2권3호
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    • pp.173-177
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    • 2014
  • This study is aimed to the numerical modeling of the surface plasmon-polariton excitation by a layer of active (electrically pumped) quantum dots embedded in a semiconductor, covered with a metal. It is shown that this excitation becomes much more efficient if the metal has a form of a thin (with thickness of several nanometers) film. The cause of this enhancement in comparison with a thick covering metal film is the partial surface plasmon-polariton localized at the metal-semiconductor interface penetration into air. In result the real part of the metal+air half-space effective dielectric function becomes closer (in absolute value) to the real part of the semiconductor dielectric function than in the case of a thick covering metal film. This leads to approaching the point of the surface plasmon-polariton resonance (where absolute values of these parts coincide) and, therefore, the enhancement of the surface plasmon-polariton excitation. The calculations were made for a particular example of InAs quantum dot layer embedded in GaAs matrix covered with an Au film. Its results indicate that for the 10 nm Au film the rate of this excitation becomes by 2.5 times, and for the 5 nm Au film - by 6-7 times larger than in the case of a thick (40 nm or more) Au film.

용액 연소법에 의한 광촉매용 나노크기의 ZnO 분말의 제조 및 특성 (Preparation and Characteristics of Nanometer-sized ZnO Powder by Solution Combustion Process for Photocatalyst Applications)

  • 이강렬;김흥회;박성
    • 한국세라믹학회지
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    • 제38권8호
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    • pp.765-770
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    • 2001
  • 광촉매용 ZnO 나노크기의 분말은 시작원료와 연료의 종류에 따라 용액연소법에 의해 제조되었다. 결정상은 XRD로부터 확인할 수 있었으며 분말의 하소온도는 TG 분석으로부터 결정되었다. 분말의 비표면적은 BET 법에 의해 측정되었으며 평균입자크기와 형태를 SEM과 TEM으로부터 조사하였다. 또한 분말의 순도를 조사하기 위해 적외선 흡수스펙트럼을 측정하였으며 광촉매 효율로서 은이 첨가된 사진현상액을 이용하여 은의 수거율을 측정하였다. 용액연소법으로 제조한 경우 시작원료와 연료에 관계없이 단상의 ZnO 분말을 쉽게 얻을 수 있었다. 그러나 합성된 ZnO 분말의 입자크기와 형태는 연료의 종류에 따라 서로 다르게 보였다. 특히, 연료로 glycine을 사용한 경우, ZnO 분말의 입자 형태는 균일한 나노 크기의 구형이었으나 carbohydrazide을 사용한 경우에는 판상과 같은 형태를 보였다. 이러한 결과를 기초로 하여 시작원료와 연료로 Zn(OH)$_2$와 glycine을 사용하여 합성된 ZnO 분말이 우수한 분말 특성을 보였으며 75nm의 입자크기와 94$m^2$/g의 비표면적을 보였다. 또한 사진현상액에 존재하는 은이 3분 이내에 완전히 제거되는 우수한 광촉매 성질을 보였다.

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Nanoscale Probing of Switching Behaviors of Pt Nanodisk on STO Substrates with Conductive Atomic Force Microscopy

  • Lee, Hyunsoo;Kim, Haeri;Van, Trong Nghia;Kim, Dong Wook;Park, Jeong Young
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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    • pp.597-597
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    • 2013
  • The resistive switching behaviors of Pt nanodisk on Nb-doped SrTiO3 single-crystal have been studied with conductive atomic force microscopy in ultra-high vacuum. The nanometer sizes of Pt disks were formed by using self-assembled patterns of silica nanospheres on Nb-doped SrTiO3 single-crystal semiconductor film using the Langmuir-Blodgett, followed by the metal deposition with e-beam evaporation. The conductance images shows the spatial mapping of the current flowing from the TiN coated AFM probe to Pt nanodisk surface on Nb:STO single-crystal substrate, that was simultaneously obtained with topography. The bipolar resistive switching behaviors of Pt nanodisk on Nb:STO single-crystal junctions was observed. By measuring the current-voltage spectroscopy after the forming process, we found that switching behavior depends on the charging and discharging of interface trap state that exhibit the high resistive state (HRS) and low resistive state (LRS), respectively. The results suggest that the bipolar resistive switching of Pt/Nb:STO single-crystal junctions can be performed without the electrochemical redox reaction between tip and sample with the potential application of nanometer scale resistive switching devices.

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A Novel Picometer Positioning System for Machine Tools and Measuring Machines

  • Mizumoto, Hiroshi;Yabuta, Yoshito;Arii, Shiroh;Tazoe, Yoichi;Kami, Yoshihiro
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.123-128
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    • 2005
  • A novel tri-mode ultraprecision positioning system for machine tools and measuring machine is proposed. The basic coarse mode uses a Twist-roller Friction Drive (abbr. TFD), and controls several tens of millimeters of the machine-table travel with nanometer order of positioning resolution. The fine mode also utilizes the TFD with a fine adjusting mechanism. The resolution of the fine mode is in the range of sub-nanometer. For realizing picometer positioning, the ultra-fine mode is executed by using an active aerostatic guideway. On the bearing surface of this active guideway, several Active Inherent Restrictors (abbr. AIRs) are embedded for controlling the table position. An AIR unit consists of a piezoelectric actuator having a through hole, one end of the hole on the bearing surface acts as an inherent restrictor. Owing to the aerostatic mechanism of the AIR, the deformation of the piezoelectric actuator in the AIR unit causes much reduced table displacement. Such motion reduction is effective for ultraprecision positioning. Current positioning resolution of the ultra-fine mode is 50pm, however the final goal of the positioning resolution is expected to be in the order of picometer.

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Capacitance - Voltage 방법을 이용한 MOSFET의 유효 채널 길이 추출 (Accurate Extraction of the Effective Channel Length of MOSFET Using Capacitance Voltage Method)

  • 김용구;지희환;한인식;박성형;이희덕
    • 대한전자공학회논문지SD
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    • 제41권7호
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    • pp.1-6
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    • 2004
  • 나노 급 소자에서의 성능이 유효 채널 길이에 대하여 더욱 민감하게 되므로 정확한 유효 채널 길이의 추출이 중요하다. 본 논문에서는 100 ㎚ 이하의 MOSFET에서 유효 채널 길이를 추출하기 위하여 새로운 정전용량-전압(Capacitance-Voltage) 방법을 제안하였다. 제안한 방법에서는 게이트와 소스와 드레인 사이의 정전용량(C/sub gsd/)를 측정하여 유효 채널 길이를 추출하였다. 그리고 추출된 유효 채널 길이와 기존의 1/β 과 Terada 방법 그리고 다른 정전용량-전압 방법의 추출된 유효 채널 길이의 결과들과 비교하여 본 논문에서 제안한 추출방법이 100 ㎚ 이하 크기의 MOSFET의 유효 채널 길이를 추출함에 타당함을 증명하였다.