• 제목/요약/키워드: Reactions

검색결과 7,591건 처리시간 0.031초

Synthesis rind Reactions of Silacyclopropene or 1-Sila-1,2-Propadiene

  • Park, Seung-Ki
    • Journal of Photoscience
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    • 제9권1호
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    • pp.1-4
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    • 2002
  • This brief review deals with the thermal or photochemical synthesis and reactions of silacyclopropene or 1-sila-1,2-propadiene. The novel intramolecular reactions of silacyclopropene or 1-sila-1,2-propadiene are also discussed.

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화학반응을 수반하는 극초음속 희박류 유동의 직접모사법 개발 (A DSMC Technique for the Analysis of Chemical Reactions in Hypersonic Rarefied Flows)

  • 정찬홍;윤성준
    • 한국전산유체공학회지
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    • 제4권3호
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    • pp.63-70
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    • 1999
  • A Direct simulation Monte-Carlo (DSMC) code is developed, which employs the Monte-Carlo statistical sampling technique to investigate hypersonic rarefied gas flows accompanying chemical reactions. The DSMC method is a numerical simulation technique for analyzing the Boltzmann equation by modeling a real gas flow using a representative set of molecules. Due to the limitations in computational requirements. the present method is applied to a flow around a simple two-dimensional object in exit velocity of 7.6 km/sec at an altitude of 90 km. For the calculation of chemical reactions an air model with five species (O₂, N₂, O, N, NO) and 19 chemical reactions is employed. The simulated result showed various rarefaction effects in the hypersonic flow with chemical reactions.

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스모그 챔버에서 수분 반응에 의한 대기 에어로졸의 생성 및 성장 (Formation and Growth of Atmospheric Aerosols by Water Vapor Reactions in an Indoor Smog Chamber)

  • 김민철;배귀남;문길주;박주연
    • 한국대기환경학회지
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    • 제20권2호
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    • pp.161-174
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    • 2004
  • Aerosol formation and growth by water vapor reactions were investigated in a 2.5 -㎥ indoor smog chamber filled with the unfiltered ambient air. The relative humidity of test ambient air was elevated at 59~64% or 84~88% by adding water vapor. The aerosol number size distribution and the concentrations of $O_3$, NO, NO$_2$, and SO$_2$ were measured during the experiments. The $O_3$ and NO$_2$ gases were well reacted with the water vapor at high relative humidity of 84~88%, and the reaction rates of these gases seemed to be decreased at low relative humidity of 59~64%. The formation and condensational growth phenomena of ambient aerosols by water vapor reactions were observed in a Teflon bag, depending strongly on the initial particle size distribution. The water vapor reactions might be affected by the contents of oxidants produced by photochemical reactions under sunlight.

$SiH_2Cl_2-H_2-HCl$ 시스템에서의 실리콘 선택적 성장에 대한 표면 반응메커니즘 고찰 (A Study on the Reaction Mechanism of Selective Epitaxial Growth in $SiH_2Cl_2-H_2-HCl$ System)

  • 김봉수;한승오;박정호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 D
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    • pp.1288-1290
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    • 1998
  • Three most dominant reactions are adsorption, movement, and desorption of $SiCl_2$ on silicon surface. $SiCl_2$ plays a key role in these dominant reactions. In this paper, surface reactions of $SiH_2Cl_2-H_2-HCl$ system are investigated and few dominant reactions were identified. An equation for Si net growth rate is derived from the analysis of these reactions and it is compared with experimental results of Bolem and Classen.

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치과 치료에 대한 심한 공포가 있는 환자들에서 미다졸람 정주 후 나타난 기이반응 -증례보고- (Paradoxical Reactions following Intravenous Midazolam in Patients with Severe Anxiety for Dental Treatment -A Case Report-)

  • 오세리
    • 대한치과마취과학회지
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    • 제9권1호
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    • pp.30-35
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    • 2009
  • Intravenous midazolam has been frequently used for the relief of anxiety in dental treatment. This is likely the result of the sedative and anterograde amnestic properties of midazolam that are mediated through $\gamma$-Aminobutyric acid agonism. Unfortunately, Paradoxical reactions to midazolam include agitation, talkativeness, confusion, disinhibition, aggression,violent behavior, act of self-injury and need for restraints. These occur in less than 1% of all patients receiving midazolam, may occur at variable times after administration and are difficult to predict and diagnose. Two women with severe anxiety for dental treatment experienced paradoxical reactions associated with the use of intravenous midazolam. We are reviewed the management and prevention of paradoxical reactions and its different etiology.

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Effects of Competition between Phase Separation and Ester Interchange Reactions on the Phase Behavior in a Phase-Separated Immiscible Polyester Blend: Monte Carlo Simulation

  • Youk, Ji-Ho;Jo, Won-Ho
    • Fibers and Polymers
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    • 제2권2호
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    • pp.81-85
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    • 2001
  • The effects of rate of phase separation to ester interchange reactions and the repulsive pair interaction energy on the phase behavior in a phase-separated immiscible polyester blend are investigated using a Monte Carlo simulation method. The time evolution of structure factor and the degree of randomness are monitored as a function of homogenization time. When the phase separation is dominant over ester interchange reactions, the domain size slowly increases with homogenization time. However, when the pair interaction becomes less repulsive, the domain size does not significantly change with homogenization time. On the other hand, when ester interchange reactions are dominant over the phase separation, the homogenization proceeds without a change in the domain size. The higher the extent of phase separation, the lower the increasing rate of the DR. However, when the phase separation is sufficiently dominant, the effect of the extent of phase separation on the increasing rate of the degree of randomness become less significant.

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Pd-Catalyzed Substitution Reactions with Organoindium Reagents in situ Generated from Indium and Allyl or Propargyl Halides

  • Lee, Phil-Ho;Shim, Eun-Kyong;Lee, Koo-Yeon;SeoMoon, Dong;Kim, Sun-Dae
    • Bulletin of the Korean Chemical Society
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    • 제26권1호
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    • pp.157-160
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    • 2005
  • Allylindium and propargylindium reagents in situ generated from the reactions of indium with allyl halides and propargyl halides could participate as nucleophiles in Pd-catalyzed substitution reactions of allyl carbonates to produce 1,5-dienes and 1,5-enynes in good yields. $\beta$-Hydride elimination products were produced in case of carbonates having $\beta$-hydrogens. Because organoindium reagents obtained from allyl or propargyl halides and indium have previously not been used to Pd-catalyzed allylic and propargylic substitution reactions, these results should provide more opportunities for the development of new C-C bond forming reactions.

Linking Maternal Emotion Socialization to Boys' and Girls' Emotion Regulation in Korea

  • Song, Ju-Hyun;Trommsdorff, Gisela
    • Child Studies in Asia-Pacific Contexts
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    • 제6권2호
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    • pp.47-57
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    • 2016
  • This study investigated whether Korean mothers' emotion socialization beliefs are related to emotional functioning in children differing across gender. We interviewed Korean mothers (N = 100) of first graders (55 boys; 45 girls) about their sensitivity, their reactions to children's distress, and children's emotion regulation. Two components of emotion regulation were distinguished: regulation and negativity. Results revealed that mothers' proactive sensitivity and their supportive reactions were related to their children's regulation, whereas unsupportive reactions were related to children's negativity. Child gender moderated the associations between mothers' socialization beliefs and children's emotion regulation: mothers' proactive sensitivity was more strongly associated with competent regulation in girls than in boys. Mothers' unsupportive reactions were related to increased negativity only in girls. Results are discussed from a cultural perspective, focusing on gender differences in the links between maternal socialization and children's emotional outcomes in Korea.

The Measurement of Tranfer Enthalpy in Mixed Solvent (Part 2) Solvent Effects on Nucleophilic Substitution Reactions of Ethyl and 2-Phenylethyl Benzenesulfonates

  • 허철;이해황;이익춘
    • Bulletin of the Korean Chemical Society
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    • 제16권1호
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    • pp.53-58
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    • 1995
  • Heats of solution of aniline (AN), benzylamine (BA), ethyl-(EBS) and 2-phenylethyl benzenesulfonates (PEB) are calorimetrically measured in acetonitrile-methanol mixtures at 25.0 $^{\circ}C$. The activation parameters, ${\Delta}H^{\neq}$, ${\Delta}S^{\neq}$ and ${\Delta}G^{\neq}$, are determined for the reactions of EBS and PEB with AN and BA using the kinetic data at three temperatures. Calorimetric transfer enthalpies of initial state, ${\delta}H_t^{0{\rightarrow}x})$(IS), and kinetically derived activation enthalpies, ${\delta}\;{\Delta}H^{\neq}$, in the MeCN-MeOH mixtures are combined to determine the transfer enthalpies of transition state, ${\delta}H_t^{0{\rightarrow}x})$(TS); ${\delta}H_t^{0{\rightarrow}x})$(IS) = ${\delta}{\Delta}H^{\neq}\;+\;{\delta}H_t^{0{\rightarrow}x}$(IS) The preferential solvation of anionic charge in the TS predicts a loose TS with a greater degree of bond cleavage for the reactions of PEB than for EBS, and also for the reactions with BA compared to the reactions with AN.