• 한국환경과학회지
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• 제19권3호
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• pp.305-312
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• 2010

The purpose of this study is to compare the relative growth of annual ring width of red pine(Pinus densiflora), black pine(Pinus thunbergii) and pitch pine(Pinus rigida) by means of multiple regression method according to Graybill hypothesis. The obtained results are as follows. 1. The changes of rainfall have affected to tree growth during the periods of 1975 through 1978. 2. Among these pine trees, red pine was mostly influenced by environmental factors. 3. The growth of annual ring width was sensitively responded to the changes of rainfall and air temperature. 4. Among the heavy metals analyzed, the concentrations(ppm) of Lead(Pb) and Copper(Cu) were negatively effected on the growth of annual ring width of pine trees. 5. The analytical technique of annual ring width may be useful for estimation of the pollution in forest areas near industrial complexes.

• 한국식품영양과학회지
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• 제26권3호
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• pp.521-527
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• 1997

This study was aimed to investigate the nutriational status of Korean female college students who are attending school at a longdistance. Physique calssification by anthropomethic indexes, Body mass index(BMI) & Brocas' index and the body fat distrubition were investigated. The energy balance was also examined comparing caloric intake with caloric expenditure. The result of this study are followings; (1) Average height and weight were 158±17.8 cm, 51.7±7.8 kg. This results were not quite different from '84 Korean Adult Standard of 159.5cm, 52.5kg. (2) By Broca's index, 25.89% of subjects was underweight 67.0% was normal weight and 7.06 was overweight. By BMI, 40% of subjects was underweight, 58.8% was normal weight and 1.2% was overweight. (3) According to % fat measured. By BIA, 7% in subjects was underweight, 64.2% was normal weight, 22% was overweight and 6.1% was obesity. This result differed from BMI's result. It may be measurement error due to the difficulty of removing metal sticking to underwear and tooth correction. (4) The intakes of the nutrients except protein, P, vitamin B₁ complexes, were lower than the intakes indicated by Korean Recommended Allowances. 95) Average caloric intake a day was 1545±394.4 kcal, which was much lower than the RDA. The caloric expenditure was much more than caloric intake, which showed negative energy balance in the subjects of this study.

• 대한화학회지
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• 제33권6호
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• pp.582-587
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• 1989

$[Cr(NH_3)_5(DMF)]^{3+}$ 이온의 수화반응 속도를 분광광도법을 이용하여 온도와 압력을 변화시켜 가면서 측정하였다. 활성화부피(${{\Delta}V_0}^{\neq}$)는 -2.76∼-3.65$cm^3mol^{-1}$의 범위로 작은 음의 값을 나타내었다. 활성화 엔트로피(${\Delta}S^{\neq}$) 및 활성화 압축률계수(${\Delta}{\beta}^\neq$)도 모두 작은 음의 값을 가졌다. 이러한 열역학적인 활성화 파라미터로부터 이 착이온의 수화반응은 교환회합($I_a$) 메카니즘으로 진행됨을 알 수 있었다.

• Mass Spectrometry Letters
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• 제1권1호
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• pp.9-12
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• 2010

Trimethylboroxine (TMB) is a six-membered ring compound containing Lewis acidic boron and Lewis basic oxygen atoms that can bind halide anion and alkali metal cation, respectively. We employed Fourier transform ion cyclotron resonance spectroscopy to study the gas-phase binding of $LiBrLi^+$ and $F^-(KF)_2$ to TMB. TMB forms association complexes with both $LiBrLi^+$ and $F^-(KF)_2$ at room temperature, providing direct evidence for the ditopic binding. Interestingly, the $TMB{\cdot}F^-(KF)_2$ anion complex is formed 33 times faster than the $TMB{\cdot}Li^+BrLi$ cation complex. To gain insight into the ditopic binding of an ion pair, we examined the structures and energetics of $TMB{\cdot}Li^+$, $TMB{\cdot}F^-$, $TMB{\cdot}LiF$ (the contact ion pair), and $Li^+{\cdot}TMB{\cdot}F^-$ (the separated ion pair) using Hartree-Fock and density functional theory. Theory suggests that $F^-$ binds more strongly to TMB than $Li^+$ and the contact ion-pair binding ($TMB{\cdot}LiF$) is more stable than the separated ion-pair binding ($Li^+{\cdot}TMB{\cdot}F^-$).

• 한국고분자학회지:고분자과학과기술
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• 제5권3호
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• pp.236-253
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• 1994

양이온형 $d^0\;Cp_2M(R)(L)^+$ 착물과 무염기 $Cp_2M(R)^+$ 착물은 $Cp_2M(R)_2$화합물로부터 쉽게 합성할 수 있다. 이들 친전자성 착물에서는 여러가지 리간드 교환반응, 삽입반응, ${\beta}$-H 제거반응 및 ${\sigma}$-결합 복분해반응이 일어날 수 있다. 일반적으로 $Cp2M(R)(L)^+$ 착물은 불포화도와 전하가 크기때문에 중성의 $Cp_2M(R)(X)$나 $Cp_2M(R)_2$보다 반응성이 크며 $d^0\;{Cp_2}^*M(R)^+$ (M=제 3족과 란탄계) 착물과 여러가지 반응에서 유사한 거동을 보인다. $Cp_2MX_2$를 기초로하여 합성된 Ziegler-Natta 촉매에 의한 올레핀 중합에서 활성점이 $Cp_2M(R)^+$ 양이온이라는 여러가지 직접적인 증거가 발표되었다. 분리가능한 $Cp_2M(R)(L)^+$ 착물은 올레핀중합에서 높은 활성을 보이며, 유기합성의 관점에서 흥미있는 C-C 재조합반응과 같은 다른 여러가지 반응이 일어날 수 있는 기회를 제공한다.

• Bulletin of the Korean Chemical Society
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• 제28권8호
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• pp.1311-1316
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• 2007

To develop photo-sensitizers for dye-sensitized solar cells (DSCs) used in harvesting sunlight and transferring solar energy into electricity, we synthesize novel Ru(II) polypyridyl dyes and describe their characterization. We also investigate the photo-electrochemical properties of DSCs using these sensitizers. New dyes contain chromophore unit of dafo (4,5-diazafluoren-9-one) or phen-dione (1,10-phenanthroline-5,6-dione) instead of the nonchromophoric donor unit of thiocyanato ligand in cis-[RuII(dcbpy)2(NCS)2] (dcbpy = 4,4'-dicarboxy- 2,2'-bipyridine) coded as N3 dye. For example, the photovoltaic data of DSCs using [RuII(dcbpy)2(dafo)](CN)2 as a sensitizer show 6.85 mA/cm2, 0.70 V, 0.58 and 2.82% in short-circuit current (Jsc ), open-circuit voltage (Voc), fill factor (FF) and power conversion efficiency (Eff), which can be compared with those of 7.90 mA/ cm2, 0.70 V, 0.53 and 3.03% for N3 dye. With the same chelating ligand directly bonded to the Ru metal in the complex, the CN ligand increases the Jsc value by double, compared to the SCN ligand. The extra binding ability in these new dyes makes them more resistant against ligand loss and photo-induced isomerization within octahedral geometry.

• 대한화학회지
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• 제30권1호
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• pp.101-104
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• 1986

아디파알데히드, 구르타르알데히드 및 숙신알데히드와 같은 디알데히드는 물-에톡시에탄올 및 에탄올내에 촉매량의 육로듐 십육카르보닐 또는 오카르보닐철의 존재하, 70기압, 일산화탄소, 180$^{\circ}C$, 4시간동안 반응시켜 쉽게 환원되어 대응하는 1,6-헥산디올 및 1,5-펜탄디올 및 1,4-부탄디올이 좋은 수득율로 얻어졌다. 같은 조건하에서 2,5-헥산디온, 2,4-펜탄디온도 대응하는 디올이 보통 수득율로 얻어졌다. 디알데히드의 이중 히드로히드록시메틸화 반응에 대해서는 금속카르보닐 촉매가 다른 촉매보다 더욱 활성적이다. 특히 벤조퀴논은 정량적으로 히드로퀴논을 주었다.

• 대한화학회지
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• 제38권8호
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• pp.598-602
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• 1994

이핵착물 $(NC)_5FeII-L-CoIII(NH_3)_5$ 분자내에서의 광유발 전자이동반응을 정류상태 광분해 실험으로 조사하여 속도상수를 결정하고 다리리간드 L의 종류에 따른 영향을 고찰하였다. 금속 결합자리 사이에 콘쥬게이션이 유지되는 BP, PHEN, DAP 리간드는 klight가 약 $3{\times}10^{-2} sec^{-1}$, 양자수율이 상한값인 1이였으며 콘쥬게이션이 유지되지 못하는 BPEA리간드인 klight가 약 $2{\times}10^{-4} sec^{-1}$, 양자수율이 0.03으로 측정되었다. 이로부터 광유발 전자이동반응이 전하이동 들뜬 상태 MLCT*를 거치는 "화학적 메카니즘"인 것으로 증명하였다.

• Bulletin of the Korean Chemical Society
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• 제34권4호
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• pp.1127-1130
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• 2013

Formation of the monodisperse submicrospheres consisting of ionic palladium(II) complexes, $[(Me_4en)Pd(L)]_2(X)_4$($Me_4en$ = N,N,N',N'-tetramethylethylenediamine; L = bis(4-(4-pyridylcarboxyl)phenyl)methane; $X^-=BF_4{^-}$ and $ClO_4{^-}$), has been carried out without any templates or additives. The submicrospheres were coated with silicates, and then calcined in air at $550^{\circ}C$ for 1 h, to efficiently form hollow-spherical $SiO_2$ submicro-reactors dotted with palladium(0) nanoparticles (PdNPs). That is, the submicrospheres act as both a template and a source of the palladium metal nanoparticles. The submicro-reactors containing nano-catalysts have been characterized by means of SEM, TEM, and XPS. Notably, the reactors were proved to be very effective for Suzuki-Miyaura cross-coupling and hydrogenation reactions.

• 대한화학회지
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• 제13권1호
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• pp.16-24
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• 1969

Ni, Co, Zn, Cd, Mn, Mg, Ca, Sr, Ba 등의2가 금속과 U(VI) 및 V(IV)의 이온이 만드는 $MCup_2$ 조성의 cupferrates 착화합물에 관하여, 그 용해도가 좋은 dioxane-$H_2O$, methanol-$H_2O$, ethanol-$H_2O$ 및 2-propanol-$H_2O$의 혼합용매를 사용하여, 그들의 몰분율을 변화시키면서 제 1, 제 2 및 전체의 열역학적인 안정도상수를 전위차적정법에 의하여 측정하고, 안정도 상수와 유기용매의 몰분율에 관한 실험식을 얻었다. 한편 분광광전법에 의하여 가능한 cupferrates의 전체 안정도 상수를 측적하여 이들과 비교하였다. 2가 금속 cupferrates의 안정도상수는 위에 적은 금속의 순서로 감소하고, 이들의 log $K_1$은 log $K_2$보다 크지만, U(VI)과 V(IV)의 cupferrates는 log $K_1$$K_2$여서 1:1과 1:2 착화합물 사이에 구조 변화가 있는듯하다. 몰분율이 영인 점에서의 안정도상수는 금속 cupferrates의 수용액에서의 용해반응의 평형상수에 해당하며, 금속의 착화합물의 안정도상수와 용해도와는 무관하고, K<$10^5$인 cupferrates에 관해서는 분광전법을 적용하기 어렵다.