• 제목/요약/키워드: $K_{trans}$

검색결과 1,862건 처리시간 0.032초

trans-[FeH(NCS(Me)-S)(dppe)2]I 화합물의 trans-[FeNCS)2(Ph2P(O)CH2CH2P(O)Ph2)2][I3]로 산화 (Oxidation of trans-[FeH(NCS(Me)-S)(dppe)2]I to trans trans-[FeNCS)2(Ph2P(O)CH2CH2P(O)Ph2)2][I3](dppe=PPh2CH2CH2PPh2))

  • 이지화;이순원
    • 대한화학회지
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    • 제44권4호
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    • pp.311-315
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    • 2000
  • The Fe(II)-isothiocyanato complex $trans-[FeH(NCS)(dppe)_2]$ (1) eactedwith iodomethane(Mel) to give methyl isothiocyanide-Fe(n) complex, $trans-FeH(NCS(Me)-S)(dppe)_2]I(2)$. Compound 2 was oxidized to $trans-[Fe(NCS)_2(Ph_2P(O)CH_2CH_2P(O)Ph_2)_2][I_3]$ (3), which was structurally characterized by X-ray diffraction. The molecular structure of 3 showed a bent Fe-NCS group, Crystallographic data for 3: triclinic space group P1,a=11.071(2) A,b=12.054(2)A,c=12.121(1)A, $\alpha=101.02(1){\circ}C{\beta}=95.887(9){\circ}Cr=110.34(1){\circ}C$, $Z=1R(wR_2)=0.0567(0.1294)$.

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Characterization of Low Molecular Weight Polyphenols from Pine (Pinus radiata) Bark

  • Mun, Sung-Phil;Ku, Chang-Sub
    • Food Science and Biotechnology
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    • 제15권3호
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    • pp.424-430
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    • 2006
  • Low molecular weight polyphenols were isolated from hot water extracts of radiata pine (Pinus radiata) bark using a Sephadex LH-20 column and characterized by $^1H$ and $^{13}C$ NMR, UV, FT-IR, and GC-MS analyses. Major compounds isolated and identified were protocatechuic acid, trans-taxifolin, and quercetin. Trans-taxifolin, an important intermediate in biosynthetic route of proanthocyanidin (PA), was isolated in large quantities and indicates that PA is a major component of radiata pine bark. Small amounts of polyphenols were identified by GC-MS analysis. The presence of p-hydroxybenzoic acid, vanillic acid, protocatechuic acid, cis- and trans-feruic acid, p-coumaric acid, trans-caffeic acid, (-)-epicatechin, (+)-catechin, trans- and cis-taxifolin, (+)-gallocatechin, and quercetin was confirmed by comparison of mass fragmentation patterns and retention times (RT) with authentic samples. In addition, the presence of astringenin, astringenin glycoside, trans- and cis-leucodelphinidin was strongly assumed from characteristic mass fragment ions due to their conjugated structure and retro Diels-Alder reaction, and also from biosynthetic route of PA. GC-MS analysis allowed us to detect small amounts of phenolic acids and flavonoids and eventually discriminate trans- and cis-configuration in the identified polyphenols.

스위치드 변압기 Z-소스 인버터의 전압 스트레스와 전압이득 비교 (Comparison of the Voltage Stress and Voltage Gain of the Switched Trans Z-source Inverters)

  • 김세진;정영국;임영철
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2013년도 전력전자학술대회 논문집
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    • pp.376-377
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    • 2013
  • 본 연구에서는 양방향 인덕터 대신 단방향 변압기 셀을 이용한 Switched Trans Z-source inverter, Switched Trans Quasi Z-source inverter, Switched Trans-inductor Quasi Z-source inverter의 전압 이득 및 스트레스를 비교하였다.

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ON SOME PROPERTIES OF SEMI-INVARIANT SUBMANIFOLDS OF A NEARLY TRANS-SASAKIAN MANIFOLD ADMITTING A QUARTER-SYMMETRIC NON-METRIC CONNECTION

  • Ahmad, Mobin;Jun, Jae-Bok;Siddiqi, Mohd Danish
    • 충청수학회지
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    • 제25권1호
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    • pp.73-90
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    • 2012
  • We define a quarter-symmetric non-metric connection in a nearly trans-Sasakian manifold and we consider semi-invariant submanifolds of a nearly trans-Sasakian manifold endowed with a quarter-symmetric non-metric connection. Moreover, we also obtain integrability conditions of the distributions on semi-invariant submanifolds.

${\alpha}-Tocopherol$이 첨가된 Methyl Linoleate의 산화물 생성 기구 (Oxidation Mechanism of Methyl Linoleate with ${\alpha}-Tocopherol$)

  • 김정숙;이기동;권중호;윤형식
    • 한국식품과학회지
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    • 제25권6호
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    • pp.614-619
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    • 1993
  • Methyl linoleate에 ${\alpha}-Tocopherol$을 첨가하여(TML) $37^{\circ}C$에서 9일간 산화시키면서 산화생성물의 확인 및 생성기구에 대하여 GC/MS를 사용하여 검토하였다. TML군에서의 산화 생성물들은 methyl octanoate와 methyl-8-(2-furyl)-octanoate 및 9,13-trans, cis isomer와 9,13-trans, trans isomer로 밝혀졌다. 전보의 methyl linoleate(ML)에서의 산화생성물과 비교하여 볼 때 9-TMSO-12,13-epoxy-10-octadecenoate 대신 methyl octanoate가 생성되었다. ${\alpha}-Tocopherol$의 주된 산화물인 ${\alpha}-Tocopherol$ quinone은 반응 6일부터 생성되었으며, ${\alpha}-Tocopherol$은 aqueous media보다 lipid media에서 산화가 빨리 진행되는 것으로 나타났다. Methyl linoleate의 산화에 의한 생성물들의 생성과정 기구를 추정한 결과, 우선 methyl-9,13-hydroxy-octadecadienoate가 생성되고 다시 methyl-9-hydroxy-10 trans, 12 trans-octadecadienoate로부터 methyl-8-(2-furyl)-octanoate와 9-TMSO-12,13-epoxy-10-ortadecenoate 및 methyl octanoate가 생성된 것으로 사료되었다.

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SPECTRAL AND PROTOPHYSICAL PROPERTIES OF 1-PYRAZINYL-2-(3- QUINOLINYL)ETHYLENE

  • Bong, Pill-Hoon;Ryoo, Jae-Hwan
    • Journal of Photoscience
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    • 제6권4호
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    • pp.171-176
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    • 1999
  • The spectral and photophysical properties of trans-1-pyrazinyl-2-(3-quinolinyl)ethylene (trans-3- PyQE) are investigated under various conditions in order to obtain information on ground and excited states. The absorption spectrum of trans-3-PyQE changes slightly with varying degree of solvent polarity ; the. fluorescence spectrum is shifted to the red and becomes broad and structureless as the solvent polarity increases. The fluorescence quantum yield increases with increasing solvent polarity. The fluorescence intensity of trans-3-PyQE decreases as the concentration of methyl iodide increases. The fluorescence spectra of trans-3-PyQE changes markedly upon the variation of the excitation wavelength, presumably due to an equilibrium between conformers originating from the rotation of a quasi-single bond between the quinolinyl group and ethylenic carbon atom. These results indicate that the spectral and photophysical properties of trans-3-PyQE are strongly influenced by solvent, heavy atom, and an equilibrium between conformers

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η-RICCI SOLITONS ON TRANS-SASAKIAN MANIFOLDS WITH QUARTER-SYMMETRIC NON-METRIC CONNECTION

  • Bahadir, Oguzhan;Siddiqi, Mohd Danish;Akyol, Mehmet Akif
    • 호남수학학술지
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    • 제42권3호
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    • pp.601-620
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    • 2020
  • In this paper, firstly we discuss some basic axioms of trans Sasakian manifolds. Later, the trans-Sasakian manifold with quarter symmetric non-metric connection are studied and its curvature tensor and Ricci tensor are calculated. Also, we study the η-Ricci solitons on a Trans-Sasakian Manifolds with quartersymmetric non-metric connection. Indeed, we investigated that the Ricci and η-Ricci solitons with quarter-symmetric non-metric connection satisfying the conditions ${\tilde{R}}.{\tilde{S}}$ = 0. In a particular case, when the potential vector field ξ of the η-Ricci soliton is of gradient type ξ = grad(ψ), we derive, from the η-Ricci soliton equation, a Laplacian equation satisfied by ψ. Finally, we furnish an example for trans-Sasakian manifolds with quarter-symmetric non-metric connection admitting the η-Ricci solitons.

CIS-TRANS ISOMERISM OF 2, 2'-DIMETHOXYAZOBENZENE

  • Park, Koon-Ha
    • Journal of Photoscience
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    • 제1권1호
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    • pp.61-62
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    • 1994
  • Upon exposure to daylight, trans-2,2'-dimethoxyazobenzene isomerized to give a equilibrium mixture of 70% cis and 30% trans isomer. The high photo-steady concentration of cis isomer is discussed compared with that of azobenzene.

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초등학생의 트랜스 지방과 관련된 인식수준 및 식행동 실태조사 (Elementary Students' Perception and Behaviors Relating to Trans Fatty Acid)

  • 차명화;김유경
    • 한국식품조리과학회지
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    • 제25권3호
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    • pp.357-364
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    • 2009
  • The objectives of this study was to explore the knowledge, attitudes, and perceptions of elementary school students towards trans fatty acids. In addition, the students' preferences and consumption frequencies of processed food items containing trans fats, as well as their food behaviors relating to snack consumption, were investigated. The study population consisted of students from seven provinces, including Seoul, Busan, Daegu, Kwangju, Gyungnam, Chungnam, and Kangwon. Two schools were selected in each province and one class was randomly chosen in each school. All students from the selected classes were surveyed onsite (N=951). The data were analyzed with chi-square tests and t-tests using SPSS/Windows (ver.15.0) program. The results showed that the students' knowledge levels toward trans fatty acid were very low, particularly on the production process of trans fats. The students perceived that trans fatty acids can cause health problems and should be consumed in low amounts. They also felt there is a need for a good nutrition education on trans fats. Furthermore, the students responded that their most preferred foods were in the order of breads, biscuits, and snacks. The most frequently consumed snack item among 2nd graders was biscuits and among 5th graders it was breads. It was also found that 90% of the students had snacks once a day, and of them, 58% prepared their own snacks. Based on this, we propose that students who allowed to choose their own snacks should be carefully educated on trans fatty acids to prevent excessive consumption of high trans fat foods.

안정성이 우수한 신남알데히드 자가미세유화 약물전달시스템 개발 (Development of trans-cinnamaldehyde self-microemulsifying drug delivery system(SMEDDS) with superior stability)

  • 방규호;김경수
    • 한국산학기술학회논문지
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    • 제20권12호
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    • pp.555-562
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    • 2019
  • 본 연구의 목적은 다양한 항균활성을 지닌 천연물 유래 물질 신남알데히드를 이용한 안정한 자가미세유화 약물전달시스템을 개발하는 것이다. 이러한 목표를 달성하기 위하여 신남알데히드의 주 분해산물인 신남산과 신남알데히드의 동시 정량법을 확립하였으며, 설정된 분석법을 이용한 용해도 시험으로 신남알데히드에 대한 용해도 개선효과가 우수한 계면활성제를 선별하였다. 계면활성제로 Cremophor EL, 공계면활성제로 Transcutol P를 이용한 신남알데히드의 pseudo-ternary phase diagram을 작성하여 에멀전의 입자크기를 최소화시킬 수 있는 조성비로 신남알데히드 : Cremophor EL : Trasncutol P = 10 : 70 : 20%(v/v/v)인 SMEDDS 조성물을 제조한 후 안정성 시험을 통해 신남알데히드의 함량변화 및 에멀전의 입자크기 변화에 대해 확인하였다. 본 연구를 통해 제조된 신남알데히드의 자가유화 나노에멀전은 신남산의 생성량이 적고 신남알데히드의 함량 저하 속도가 느려 안정성이 우수하였으며, 안정성 기간 중에 최초의 입자크기를 잘 유지하는 특성이 확인되었다. 따라서 이 조성물은 신남알데히드를 위한 의약품 제형으로의 활용 가능성이 높을 것으로 사료된다.