• 제목/요약/키워드: Chemical stability

검색결과 3,529건 처리시간 0.024초

기판온도가 전자비임으로 제작된 텅스텐 산화물박막의 화학적 안정성에 미치는 영향 (The influence of substrate temperature on the chemical stability of WO3Films prepared by electron beam deposition)

    • 한국진공학회지
    • /
    • 제5권4호
    • /
    • pp.365-370
    • /
    • 1996

  • 전기적 착색 텅스텐 산화물박막의 전자비임 증착으로 제작하였으며 제작된 막의 화학적 안정성의 기판온도 의존성을 연구하였다. 실험결과로부터, 제작된 시료의 광학적 특성과 화학적 안정성은 강하게 기판온도에 의존하였다. 기판온도 $80^{\circ}C$에서 제작된 $WO_3$막은 유기성 용액 0.6몰 $LiClO_4$속에서 착색과 탈색이 반복되어도 가장 안정하였다.

  • PDF

Bonding and Electronic Considerations in the Apex Bridged $M_2(OR)_6L_x(\mu-X)$ Complexes (M = Mo ; R = -t-Bu, -i-Pr ; L = Py ; x = 0 or 2 ; X = CO, SO$_2$, HCCH, H, and Cl)

  • Ko, Jae-Jung
    • Bulletin of the Korean Chemical Society
    • /
    • 제9권3호
    • /
    • pp.121-126
    • /
    • 1988

  • The molecular interaction of $Mo_2(OR)_4({\mu}-OR)_2$$ unit has been studied for carbonyl and acetylene ligands by means of extended Huckel calculations. We have extended the extended Hckel calculations to unknown apex bridged $Mo_2(OR)_6({\mu}-X)$ complexes (X = $SO_2$H, and Cl) in order to compare the stability of the complexes. In the $C_2H_2$and H apex bridged complexes, one finds a relatively small HOMO-LUMO gap. However, both complexes are stabilized due to Jahn-Teller distortion. The stability of both complexes is comparable to that of $Mo_2(OR)_6(CO)$ complex. The comparisons and predictions in the stability of known and unknown complexes are the subject of this study.

  • https://doi.org/10.5012/bkcs.1988.9.3.121 인용 PDF

Numerical Simulation on the Onset of Radial Fingering in a Hele-Shaw Cell or a Porous Medium

  • Min Chan Kim
    • Korean Chemical Engineering Research
    • /
    • 제62권1호
    • /
    • pp.112-117
    • /
    • 2024

  • Numerical simulations on the onset and the growth of viscous fingering during the miscible displacement due to the radial source flow were conducted. With introduction of a new stability criterion, the critical log-viscosity ratio, Rc, was found as a function of the Peclet number, Pe. Similar to the previous linear stability analyses, Pe made the system unstable, i.e., accelerated the onset of instability. For a large Pe system, the present numerical simulation yielded much stable results than the previous theoretical predictions This discrepancy was commonly encountered in the comparison between the theoretical prediction and the experimental finding. Additionally, the difference between the rectilinear system and the present one was also discussed. The present system was found more insensitive to the Peclet number than the rectilinear one.

  • https://doi.org/10.9713/kcer.2024.62.1.112 인용 PDF

효소단백질 열안정성의 분자구조적 특성 및 증진기법 (Some Molecular Characteristics and Improving Methods for Thermal Stability of Enzyme)

  • 김남수;김수일
    • 한국미생물·생명공학회지
    • /
    • 제19권1호
    • /
    • pp.100-108
    • /
    • 1991

  • Molecular characteristics and improving methods for thermal stability of enzyme have been considered. Intrinsic and extrinsic stabilizing mechanisms are two governing principles for enhanced thermal stability of enzyme in molecular basis. Factors contributing to the former and the latter mechanisms may be involved in the enhanced thermal stability of enzyme complementarily. Also, the methods for improving thermal stability of enzyme which comprise reaction in organic solvent system, chemical modification, immobilization, sequential unfolding and refolding, gene manipulation techniques and enzyme-antibody complexing are reviewed.

  • PDF