• 대한화학회지
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• 제54권4호
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• pp.402-410
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• 2010

새로운 착물인 cis-[$Mo_2O_3(Hapdhba)_2$], trans-[$UO_2(Hapdhba)_2$], [Pd(Hapdhba)Cl($H_2O$)], [Pd(bpy)(Hapdhba)]Cl, [Ag(bpy) (Hapdhba)], [$Ru(Hapdhba)_2(H_2O)_2$], [$Rh(Hapdhba)_2Cl(H_2O)$] 및 [Au(Hapdhba)$Cl_2$]를 보고한다. 여기서 $H_2$apdhba는 2-aminopyrimidine 및 2,4-dihydoxybenzaldehyde에서 비롯된 Schiff-염기이다. 이들 착물은 IR, UV-Vis 그리고 질량 스펙트럼을 비롯하여 전기전도도, 자기 및 열 분석을 통해 특성을 조사하였다. 구리의 부식에 대한 $H_2$apdhba의 방해효과는 0.5 M HCl에서 potiodynamic polarization 측정을 통해 조사하였다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1997년도 춘계학술발표회논문집(2)
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• pp.74-79
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• 1997

$UO_2$ 및 $UO_2$-3.23wt%CeO$_2$가 128$0^{\circ}C$에서 소결되면 밀도는 각각 93%T.D., 91.2%T.D.이었으나, Li$_2$O가 0.lwt%씩 첨가된 경우에는 소결밀도가 95.5%T.D., 95.1%T.D.로 증가하였다. 소결온도가 증가함에 따라서 $UO_2$ 및 $UO_2$-3.23wt%CeO$_2$의 소결밀도는 현저하게 증가되는 반면에, Li$_2$O가 첨가된 경우에는 저온에서도 이미 치밀화가 많이 일어났기 때문에 소결밀도의 증가폭이 완만하였다. Li$_2$O가 첨가된 분말에서는 소결온도가 더 높아지면, 결정립성장이 주로 일어나게 되어 168$0^{\circ}C$에서 소결되었을 때, $UO_2$와 $UO_2$-0.1wt%Li$_2$O의 결정립크기가 각각 8.7$\mu\textrm{m}$, 120$\mu\textrm{m}$ 이고, $UO_2$-3.23wt%CeO$_2$와 $UO_2$-3.23wt%CeO$_2$-0.lwt%Li$_2$O는 각각 10.9$\mu\textrm{m}$, 34$\mu\textrm{m}$ 이었다. $UO_2$와 $UO_2$-3.23wt%CeO$_2$ 그리고, 두 조성에 Li$_2$O가 각각 첨가된 경우, Ar-4vol.%H$_2$ 분위기보다 H$_2$분위기에서 소결했을 때 밀도가 더 높았다. 그러나, 결정립은 $UO_2$와 $UO_2$-Li$_2$O의 경우, 수소분위기에서 소결했을 때, (U,Ce)O$_2$와 (U,Ce)O$_2$-Li$_2$O에서는 Ar-4vol.%H$_2$분위기에서 소결했을 때 더욱 성장하였다.

• 대한화학회지
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• 제23권2호
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• pp.94-98
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• 1979

2-Amino-와 2-nitro-3,4-dihydro-5,6-dimethoxy-1(2H)-naphthalenone의 촉매수소화에서 주생성물인 2-amino-5,6-dimethoxy-1,2,3,4-tetrahydronaphthalene을 얻었고 동시에 극소량의 5,6-dimethoxy-1,2,3,4-tetrahydro-2(1H)-naphthalenone을 얻었다. 이 전이된 생성물의 구조결정은 ir와 nmr, 그리고 원소분석으로 확인하였고 전이메카니즘을 제시하였다.

• 대한수학회지
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• 제47권2호
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• pp.263-275
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• 2010

Let {$X_n;n\;\geq\;1$} be a strictly stationary sequence of negatively associated random variables with mean zero and finite variance. Set $S_n\;=\;{\sum}^n_{k=1}X_k$, $M_n\;=\;max_{k{\leq}n}|S_k|$, $n\;{\geq}\;1$. Suppose $\sigma^2\;=\;EX^2_1+2{\sum}^\infty_{k=2}EX_1X_k$ (0 < $\sigma$ < $\infty$). We prove that for any b > -1/2, if $E|X|^{2+\delta}$(0<$\delta$$\leq$1), then $$lim\limits_{\varepsilon\searrow0}\varepsilon^{2b+1}\sum^{\infty}_{n=1}\frac{(loglogn)^{b-1/2}}{n^{3/2}logn}E\{M_n-\sigma\varepsilon\sqrt{2nloglogn}\}_+=\frac{2^{-1/2-b}{\sigma}E|N|^{2(b+1)}}{(b+1)(2b+1)}\sum^{\infty}_{k=0}\frac{(-1)^k}{(2k+1)^{2(b+1)}}$$ and for any b > -1/2, $$lim\limits_{\varepsilon\nearrow\infty}\varepsilon^{-2(b+1)}\sum^{\infty}_{n=1}\frac{(loglogn)^b}{n^{3/2}logn}E\{\sigma\varepsilon\sqrt{\frac{\pi^2n}{8loglogn}}-M_n\}_+=\frac{\Gamma(b+1/2)}{\sqrt{2}(b+1)}\sum^{\infty}_{k=0}\frac{(-1)^k}{(2k+1)^{2b+2'}}$$, where $\Gamma(\cdot)$ is the Gamma function and N stands for the standard normal random variable.

• 농약과학회지
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• 제17권2호
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• pp.140-143
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• 2013

톱다리개미허리노린재의 페로몬 성분인 (E)-2-hexenyl (E)-2-hexenoate (1) 과 (E)-2-hexenyl (Z)-3-hexenoate (2)의 합성에 있어 Steglich 에스테르화 반응의 최적 조건을 검토하였다. (E)-2-헥센산 또는 (Z)-3-헥센산에 대하여 1-1.5 당량의 디사이클로카보다이이미드 (DCC), 1.5-2.0 당량의 (E)-2-헥센놀과 0.1 당량의 4-디메틸아미노피리딘(DMAP)과 반응하였을 때, 각각 76-78% 와 87-91%의 수율로 1과 2를 얻었다.

• Archives of Pharmacal Research
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• 제25권5호
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• pp.590-599
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• 2002

Eight rigid compounds designed as esterase-stable analogues of methyl 2,5-dihydroxycinnamate (1) were synthesized. These derivatives include 2-(2',5'-dihydroxybenzylidene)cyclopentenone (3a), 2-(2',5'-dihydroxybenzylidene)cyclohexanone (3b), 2,6-bis(2',5'-dihydroxybenzy-lidene)cyclohexanone (4b), 2,6-bis(2',5'-dihydroxybenzylidene)cyclopentenone (4a), (E)-3-(2',5'-dihydroxybenzylidene)pyrrolidin-2-one (5), (E)-5-(2',5'-dihydroxybenzylidene )-1,2-isothiazolidine-1,1-dioxide (6), 4-(2',5'-dihydroxyphenyl)-5H-furan-2-one (7), and 3-(2',5'-dihydroxyphenyl)cyclopent-2-ene-1-one (8). Among the eight compounds, the furanone 7 and cyclopentenone 8 showed the most potent cytotoxicity with $IC_{50}$ values of 0.39-0.98 $\mu\textrm{g}$/mL. Compound 8 was further brominated, phenylated and methylated at the a position to give three corresponding analogues, including 2-bromo-3-(2',5'-dihydroxyphenyl)cyclopent-2-ene-1-one (24), 3-(2',5'-dihydroxyphenyl)-2-phenylcyclopent-2-ene-1-one (27), and 3-(2',5'-dihydroxyphenyl)-2-methylcyclopent-2-ene-1-one (28). Among the three, the most enhanced activity was observed with the phenylated compound 27.

• 한국세라믹학회지
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• 제26권2호
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• pp.210-220
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• 1989

The properties of the powder of Al2O3-15v/o ZrO2(＋3m/o Y2O3) system prepared by co-precipitation method at the pH values of 7, 9, 10 and 11 were investigated. Al2(SO4)3.18H2O, ZrOCl2.8H2O and YCl3.6H2O were used as starting materials and NH4OH as a precipitation agent. Zirconium hydroxide decreased the specific surface area of aluminum hydroxide of AlOOH type, while increased the specific surface area of aluminum hydroxide of Al(OH)3 type, and formed co-network structure of Al-O-Zr type with the aluminum hydroxides. The rate of transition to $\alpha$-Al2O3 from co-precipitated materials occurred in the order of 7≒10, 9 and 11 of pH values. Al2O3 and ZrO2 interacted to bring about coupled grain growth, and the growth of ZrO2 crystallite size rapidly occurred within $\theta$-Al2O3 matrix. Segregation did not occur in the system Al2O3-15v/o ZrO2(＋3m/o Y2O3) and Y2O3 acted as a stabilizer to ZrO2. The lattice strain of tetragonal ZrO2 was increased by the constraint effect of Al2O3 matrix.

• 한국세라믹학회지
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• 제28권5호
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• pp.422-428
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• 1991

The reaction sintering of Al2O3-ZrO2-Nb composite has been investigated using Al2O3, and ZrAl2 powders. Two kinds of specimens, 78.3Al2O3-14.0Nb2O5-7.7ZrAl2 in wt.% (AZN-5) and 72.3Al2O3-13.8Nb2O5-7.5ZrAl2-6.4ZrO2(AZN-10), were prepared. Powder compacts were sintered at various temperatures between 1$600^{\circ}C$ and 1$700^{\circ}C$ for 30 min in Ar. DTA and X-ray analysis have showen that a reaction between Nb2O5 and ZrAl2 started at 149$0^{\circ}C$ to form Al2O3, ZrO2, and Nb. The sintered density increased with the sintering temperature. AZN-10 specimen showed higher density than AZN-5 specimen for almost all the experimental conditions. Al2O3-ZrO2-Nb composite hot pressed after reaction sintering showed higher toughness and lower hardness than hot pressed Al2O3-ZrO2. The crack propagated through many metallic Nb particles which showed plastic deformation, and this is the cause of the increase in toughness of Al2O3-ZrO2-Nb composite over Al2O3-ZrO2.

• Bulletin of the Korean Chemical Society
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• 제31권12호
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• pp.3600-3604
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• 2010

Rhodium(III)-$Cp^*$ complexes containing labile ligands, $[Cp^*RhCl_2]_2$, [$Cp^*Rh({\eta}^2-NO_3)$(OTf)], and $[Cp^*Rh(OH_2)_3](OTf)_2$, reacted with potential linking ligands [$L^1$ = (2-thiophene)-CH=N-N=CH-(2-thiophene); $L^2$ = (2-furan)-CH=N-N=CH-(2-furan)] to give two molecular compounds, [$Cp^*Rh(L^1)Cl_2$] (1) and [$Cp^*Rh({\eta}^2-NO_3)(L^1)$]$(OTf){\cdot}CH_2Cl_2$ ($2{\cdot}CH_2Cl_2$), and one 1-dimensioanl coordination polymer, $\{[Rh(L^2)]{\cdot}(OTf)}_{\infty}$ (3). Whereas one imine nitrogen atom within the ligand is coordinated to the Rh metal in compounds 1 and 2, both nitrogen atoms are bound to two neighboring Rh metals in compound 3 to lead to a 1-D chain polymer.

• Bulletin of the Korean Chemical Society
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• 제27권11호
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• pp.1839-1843
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• 2006

Hydrothermal reactions of $Ln(NO_3)_3{\cdot}5H_2O $ (Ln = Eu (1), Sm (2), Ho (3), Dy (4)) with 3,5-pyridinedicarboxylic acid (3,5-pdcH2) in the presence of 4,4'-bipyridine led to the formation of the 3-D Ln(III)-coordination polymers with a formula unit of $[Ln_2(3,5-pdc)_2(C_2O_4)(H_2O)_4]{\cdot}2H_2O$. These polymers contain a bridging oxalate ligand ($C_2O_4\;^2$). On the basis of GCMS study of the mother liquor remaining after the reaction, we proposed that the $C_2O_4\;^2$ formation proceeds in three steps: (1) Ln(III)-mediated decarboxylation of $3,5-pdcH_2$ to give $CO_2$, (2) the reduction of $CO_2$ to $CO_2\;^{\cdot}$ by the Ln(II) species, and (3) the reductive coupling of the two $CO_2\;^{\cdot}$ radicals to the oxalate ($C_2O_4\;^2$) ion. All polymers were structurally characterized by X-ray diffraction.