• 제목/요약/키워드: C2

검색결과 98,540건 처리시간 0.091초

요오드벤젠과 할로겐 또는 할로겐間化合物 사이의 錯物에 관한 연구 (The Complexes of Iodobenzene with Halogens and Interhalogens in Carbon Tetrachloride)

  • 최상업;김응렬
    • 대한화학회지
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    • 제11권3호
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    • pp.94-99
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    • 1967
  • 요오도벤젠과 요오드, 일브롬화요오드, 일염화요오드 또는 염소와의 각 系를 사염화탄소 용액에서 分光光度法에 의하여 연구한 결과 $C_6H_5I{\cdot}I_2$, $C_6H_5I{\cdot}IBr$, $C_6H_5I{\cdot}ICl$, 또는 $C_6H_5I{\cdot}Cl_2$, 의 錯物이 형성됨을 알았다. 이들 錯物형성에 대한 실온(약 $21^{\circ}C$)에서의 평형상수는 각각 0.23, 0.73, 1.2 및 0.070 l $mole^{-1}$이다. 이 결과와 문헌에 보고된 결과를 종합하면 이러한 錯物의 상대적 안정도가 다음 순서로 감소함을 알 수 있다. ICl>IBr>$I_2$>$Br_2$>$Cl_2$ $C_6H_5I$>$C_6H_6$>$C_6H_5Br$>$C_6H_5Cl$>$C_6H_5F$

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$LiTaO_3$ 단결정의 완전용융조성 (Congruent Melt Composition of $LiTaO_3$ Single Crystal)

  • 정대식;박병학;김유성;노용래
    • 한국결정성장학회지
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    • 제3권2호
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    • pp.99-106
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    • 1993
  • 열분석(DTA : Differential Thermal Analysis) 방법에 의한 퀴리온도$(T_c)$ 측정방법으로부터 48.50에서 49 $Li_2O$ mole %까지의 퀴리온도$(T_c)$$Li_2O$ mole %(C)의 관계식 $(T_c = -17.869C^2+1840.2C-46623)$을 구하였다.$LiTaO_3$ 단결정의 congruent 조성을 결정하기 위하여 48.60 부터 48.70 mole %까지의 영역에서 쵸크랄스키법으로 $LiTaO_3$ 단결정을 육성하고 Top과 Tail 결정에서의 퀴리온도 차이,${\Delta}{T_c} (T_{c(Top)}-T{_c(Tail)})$ 그리고 결정성장 초기와 말기의 융액과 결정의 조성비로부터 분배계수(k)를 구하였다. 이 결과로부터 결정된 congruent 조성은 48.65 mole %였으며 그때의 $(T_c)$ 값은 $610{\pm}1^{\circ}C$였다.

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탄화규소 CVD 공정에서 CH3SiCl3-H2과 C3H8-SiCl4-H2계의 열역학적 비교 (Thermodynamic Comparison of Silicon Carbide CVD Process between CH3SiCl3-H2 and C3H8-SiCl4-H2 Systems)

  • 최균;김준우
    • 대한금속재료학회지
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    • 제50권8호
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    • pp.569-573
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    • 2012
  • In order to understand the difference in SiC deposition between the $CH_3SiCl_3-H_2$ and $C_3H_8-SiCl_4-H_2$ systems, we calculate the phase stability among ${\beta}$-SiC, graphite and silicon. We constructed the phase-diagram of ${\beta}$-SiC over graphite and silicon via computational thermodynamic calculation considering pressure (P), temperature (T) and gas composition (C) as variables. Both P-T-C diagrams showed a very steep phase boundary between the SiC+C and SiC region perpendicular to the H/Si axis, and also showed an SiC+Si region with a H/Si value of up to 6700 in the $C_3H_8-SiCl_4-H_2$, and 5000 in the $CH_3SiCl_3-H_2$ system. This difference in phase boundaries is explained by the ratio of Cl to Si, which is 4 for the $C_3H_8-SiCl_4-H_2$ system and 3 for the $C_3H_8-SiCl_4-H_2$ system. Because the C/Si ratio is fixed at 1 in the $CH_3SiCl_3-H_2$ system while it can be variable in the $C_3H_8-SiCl_4-H_2$ system, the functionally graded material is applicable for better mechanical bonding during SiC coating on graphite substrate in the $C_3H_8-SiCl_4-H_2$ system.

반응 가압 소결 방법으로 합성된 nano laminating $Ti_3SiC_2$의 기계적 특성 (Mechanical Properties of Synthesized Nano Laminating $Ti_3SiC_2$ by Reaction Press Sintering)

  • 황성식;박상환;김찬묵
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2003년도 춘계학술대회 논문집
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    • pp.396-400
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    • 2003
  • A new synthesis process for nano laminating Ti$_3$SiC$_2$ has been developed using TiCx (x=0.67) and Si powder as starting materials by a reaction hot pressing. Bulk Ti$_3$SiC$_2$ was fabricated using a green body consisting of TiCx and Si by a hot pressing under the pressures of 25 MPa at 1420-1550 $^{\circ}C$ for 90 min. The synthesized Ti$_3$SiC$_2$ was consisting of only TiCx and Ti$_3$SiC$_2$. The relative density of sintered bulk Ti$_3$SiC$_2$ was increased as the hot pressing temperature was increased, which was mainly due to the increase in TiCx contents in synthesized Ti$_3$SiC$_2$. The synthesized Ti$_3$SiC$_2$ bulk was consisted of nano sized lamella structure of 20-100 nm in thickness. It was found that TiCx particles in Ti$_3$SiC$_2$ would increase the 3-point bending strength of synthesized Ti$_3$SiC$_2$ bulk. The maximum 3-P. bending strength of synthesized Ti$_3$SiC$_2$ bulk was more than 800 MPa. The Vickers hardness of synthesized Ti$_3$SiC$_2$bulk was as low as 5 Gpa, which was decreased with the indentation load. The quasi-plastic deformation behaviors were observed around indentation mark on Ti$_3$SiC$_2$.

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$\textrm{CO}_2$인 농도 및 온도 환경이 고추의 묘소질에 미치는 영향 (Effect of Elevated $\textrm{CO}_2$ and Temperature on the Seedling Characteristics in Green Pepper (Capsicum annuum L. cv, Soonjung))

  • 안종길;최영환
    • 생물환경조절학회지
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    • 제11권2호
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    • pp.51-55
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    • 2002
  • 고추(Capsicum annuum L. cv. Soonjung)의 plug tray육묘시 $CO_2$와 온도처리가 우량묘생산에 미치는 효과를 조사 분석하였다. 초장은 611 ppm의 $CO_2$를 처리하였을 경우에 20.3$^{\circ}C$와 22.6$^{\circ}C$의 고온하에서 촉진되었으나, 15.6$^{\circ}C$의 저온하에서는 촉진효과가 없었다. 엽면적과 생체중은 22.6$^{\circ}C$의 고온에서 고농도의 $CO_2$를 처리하였을 경우에 현저히 증가하였다. 잎, 줄기, 뿌리 및 총건물중은 611 ppm의 $CO_2$를 처리하였을 경우에 온도가 상승할수록 증가하였으나, 397ppm의 $CO_2$농도에서는 22.6$^{\circ}C$의 고온에서 건물중이 감소하였다. 611 ppm의 $CO_2$처리에 의한 건물중의 증가는 20.3$^{\circ}C$ 이상의 고온과 고농도의 $CO_2$에서 약 1.5배 증가하였다. C/N율은 611 ppm의 $CO_2$ 처리가 397 ppm의 $CO_2$ 농도에서보다 높고, 온도의 상승과 함께 증가하였다.

중국 C2C 전자상거래 물류서비스 품질이 고객만족도와 고객충성도에 미치는 영향 (The Influence of C2C E-commerce Logistics Service Quality on Customer Satisfaction and Customer Loyalty in China)

  • 당인결;김태인
    • 아태비즈니스연구
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    • 제13권4호
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    • pp.61-77
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    • 2022
  • Purpose - The purpose of this study was to explore the relationship between C2C logistics service quality(convenience, responsiveness, reliability, information and empathy) customer satisfaction and customer loyalty. Design/methodology/approach - This study collected 252 survey data from consumers who use C2C platform in China. Then using SPSS 24.0 in order to analyze the data. This study used SPSS 24.0 to perform empirical analysis with 252 people who use C2C platform in China. Findings - First, it was confirmed that the quality of logistics service(convenience, responsiveness, reliability, information and empathy) had a positive effect on customer satisfaction. Second, logistics service quality(convenience, responsiveness, reliability, information and empathy) positively affects the customer loyalty. Third, there is also a strong relationship between customer satisfaction and customer loyalty. Research implications or Originality - It is well known that logistics is an important part of e-commerce. Research on the influence of B2B logistics service quality on customer satisfaction and customer loyalty is more currently, but research on C2C is relatively less. Our study contributes the related research area by doing empirical analysis of the relationship between the logistics service quality and customer satisfaction and customer loyalty to provide development suggestions for C2C sellers.

Ti$_3$SiC$_2$의 소성 변형 특성에 미치는 결정립 크기의 효과 (Effect if Grain Size on Plasticity of Ti$_3$SiC$_2$)

  • 이승건
    • 한국세라믹학회지
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    • 제35권8호
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    • pp.807-812
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    • 1998
  • Mechanical properties of two types of polycrystlline {{{{ { { Ti}_{3 }SiC }_{2 } }} with different grain size were investigated. A fine grain {{{{ { { Ti}_{3 }SiC }_{2 } }} has a higher fracture strength and hardness. Plot of strength versus Vickers indentation load indicated that {{{{ { { Ti}_{3 }SiC }_{2 } }} has a high flaw tolerance. Hertzian indentation test using a spherical indenter was used to study elastic and plastic behavior in {{{{ { { Ti}_{3 }SiC }_{2 } }}. Indentation stress-strain curves of each material are made to evaluate the plasticity of {{{{ { { Ti}_{3 }SiC }_{2 } }} Both find and coarse grain {{{{ { { Ti}_{3 }SiC }_{2 } }} showed high plasticity. In-dentation stress-strain curve of coarse grain {{{{ { { Ti}_{3 }SiC }_{2 } }} deviated even more from an ideal elastic limit in-dicating exceptional plasticity in this material. Deformation zones were formed below the contact as well as around the contact area in both materials but the size of deformation zone in coarse grain {{{{ { { Ti}_{3 }SiC }_{2 } }} was much larger than that in fine grain {{{{ { { Ti}_{3 }SiC }_{2 } }} Intragrain slip and kink would account for high plasticity. Plastic behavior of {{{{ { { Ti}_{3 }SiC }_{2 } }} was strongly influenced by grain size.

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SiC계 복합체의 특성에 미치는 Boride의 영향 (Effects of Boride on Properties of SiC Composites)

  • 신용덕;주진영;전재덕;소병문;이동윤
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 추계학술대회 논문집 전기물성,응용부문
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    • pp.191-193
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    • 2004
  • The composites were fabricated, respectively, using 61vol.% SiC-39vol.% $TiB_2$ and using 61vol.% SiC-39vol.% $ZrB_2$ powders with the liquid forming additives of 12wt% $Al_2O_3+Y_2O_3$ by hot pressing annealing at $1650^{\circ}C$ for 4 hours. Reactions between SiC and transition metal $TiB_2$, $ZrB_2$ were not observed in this microstructure. The result of phase analysis of composites by XRD revealed SiC(6H, 3C), $TiB_2$, $ZrB_2$ and $YAG(Al_5Y_3O_{12})$ crystal phase on the SiC-$TiB_2$, and SiC-$ZrB_2$ composites. The ${\beta}\;{\alpha}$-SiC phase transformation was occurred on the $SiC-TiB_2$, $SiC-ZrB_2$ composites. The relative density, the flexural strength and Young's modulus showed respectively value of 98.57%, 226.06Mpa and $86.37{\times}10^3Mpa$ in SiC-$ZrB_2$ composites.

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Gymnophaiioides seoi (Digenea: Gymnophallidae) 피낭유충의 시험관내 배양 (In vitro cultivation of Gymnophalloides seoi metacercariae (Digenea: Gymnophallidae))

  • 국진아;이순형;채종일
    • Parasites, Hosts and Diseases
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    • 제35권1호
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    • pp.25-30
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    • 1997
  • 참굴큰입흡충(GMmophQHoidesseoi)은 새로운 인체 기생 장흡충으로서 최근 우리 나라에서 인체 감염의 유행이 보고된 바 있다. 이 연구는 참굴큰입흡충의 피낭유충을 시험관내에서 배양하여 성충으로 발육시킬 수 있는지 알아보고자 시행하였다. 피낭유충은 자연산 감염 굴에서 회수하였고. NCTC 109 배지에 우태아 혈청(FBS) 20%와 항생제-항진균제(Gibco) 1%를 첨가하여 사용하되 $37^{\circ}C$/5%{\;}CO_2,{\;}41^{\circ}C/8%{\;}CO_2{\;}및{\;}41^{\circ}C/5%{\;}CO_2$의 3가지 배양조건 하에서 배양하였다 배양 2일에서 5일까지 각 조건 하에서 얻은 충체를 실험 감염 C3H 마우스에서 회수한 충체와 발육 및 성숙도를 비교하였다. 배양군의 충체 크기는 길이 $200-300{\;}\mu\textrm{m}$로서 피낭유충과 비교할 때 유의한 차이를 보이지 않았으나. 마우스로부터 회수한 충체는 $300-400{\;}\mu\textrm{m}$에서 유의한 차이를 보였다. 마우스 체내, $41^{\circ}C/5%{\;}CO_2{\;}및{\;}41^{\circ}C/8%{\;}CO_2$ 조건 하에서는 모두 2일째에 충란이 형성되기 시작하였으나, $37^{\circ}C/5%{\;}CO_2$ 하에서는 배앙 5일까지도 충란이 형성되지 않았다 배양군 중에서는 $41^{\circ}C/5%{\;}CO_2$ 조건이 충체 성숙 및 충란 생산에 가장 적합하였으나 마우스 체내에서 자란 충체에 비해 자궁내 충란 수가 약 1/2에 불과하였다. 결론적으로 참굴큰입흡충의 시험관내 배양은 $41^{\circ}C/5%{\;}CO_2$ 또는 $41^{\circ}C/8%{\;}CO_2$ 조건에서 부분적으로 성공적임을 알 수 있었다.

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Iridium(Ⅲ) Complexes of η$^6$-Arenes with Olefinic and Cyclopropyl Substituents: Facile Conversion to η ³-henylallyl Complexes

  • 정현목;주광석;진종식
    • Bulletin of the Korean Chemical Society
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    • 제18권4호
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    • pp.402-405
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    • 1997
  • Olefinic and cyclopropyl group substituted arenes (C6H5Y) react with [Cp*Ir(CH3COCH3)3]A2 (A=ClO4-, OTf-) to give η6-arene complexes, [Cp*Ir(η6-C6H5Y)]2+ (1a: Y=-CH=CH2 (a),-CH=CHCH3 (b),-C(CH3)=CH2 (c),-CH-CH2-CH2 (d)). Complex 1b-1d are readily converted into η3-allyl complexes, [Cp*(CH3CN)Ir(η3-CH(C6H5)CHCH2)]+ (2a) and [Cp*(CH3CN)Ir(η3-CH2(C6H5)CH2)]+ (2b), in the presence of Na2CO3 in CH3CN. The η6-styrene complex, 1a reacts with NaBH4 to give η5-cyclohexadienyl complex, [Cp*Ir(η5-C6H6-CH=CH2)]+ (3), while with H2 it gives η6-ethylbenzene complex [Cp*Ir(η6-C6H5CH2CH3)]2+ (4). Complex 1a and 1c react with HCl to give [Cp*Ir(η6-C6H5CH2CH2Cl)]2+ (5a) and [Cp*Ir(η6-C6H5CH(CH3)CH2Cl]2+ (5b), respectively.