• Bulletin of the Korean Chemical Society
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• 제15권8호
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• pp.636-640
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• 1994

The nonstoichiometric perovskite solid solutions of the $Nd_{1-x}Sr_xFeO_{3-y}$ system for the compositions of x=0.00, 0.25, 0.50, 0.75, and 1.00 have been prepared at $1150^{\circ}C$ in the air pressure. The compound of x=0.00, NdFe$O_{3.0}$, contains only $Fe^{3+}$ ion in octahedral site and the others involves the mixed valence state between $Fe^{3+}$ and $Fe^{4+}$ ions. The mole ratio of $Fe^{4+}$ ion or the ${\tau}$-value increases steadily with the x-value and then is maximized at the compositionof x= 1.00. The nonstoichiometric chemical formulas of the system are formulated from the x, ${\tau}$ and y values. From the Mossbauer spectroscopy, the isomer shift of $Fe^{3+}$ ion decreases with the increasing x-value, which is induced by the electron transfer between the$Fe^{3+}$ and $Fe^{4+}$ ions. The transfer is made possible by the indirect interaction between $Fe^{3+}$ and$Fe^{4+}$ ions via the oxygen ion. The eg electrons of the$Fe^{3+}$ ions are delocalized over all the Fe ions. Due to the electron transfer, the activation energy of electrical conductivity is decrease with the increasing amount of $Fe^{4+}$ ion.

• 한국표면공학회지
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• 제54권5호
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• pp.213-221
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• 2021

In order to improve the energy density and safety of Li-ion batteries, the development of a separator with high thermal stability and electrolyte wettability is an important desire. Thus, the ceramic separator to replace the polymer type is one of the most promising materials that can prevent short-circuit caused by the formation of dendrite and thermal deformation. In this study, we introduce the fabrication of various anodic aluminum oxide membranes for the application of Li-ion battery separators with the advantages of improved mechanical/thermal stability, wettability, and a high rate of Li⁺ migration through the membrane. Two different types of through-holes and branched anodic aluminum oxide membranes are well used in lithium-ion battery separators, however, branched anodic aluminum oxide membranes exhibit the most improved performance with capacity (126.0 mAh g^-1 @ 0.3C), capacity drop at the high C-rate (30.6 %), and low internal resistance (8.2 Ω).

• Bulletin of the Korean Chemical Society
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• 제29권1호
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• pp.47-50
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• 2008

The diastereoselectivity of Diels-Alder reactions were studied on the silica surface supported with different concentrations of cerium ion as efficient Lewis acid catalysts under solvent-free conditions. The results showed that the diastereoselectivity of reaction was highly improved in these conditions. The cerium ion was grafted on silica surface by using ion exchange method.

• Bulletin of the Korean Chemical Society
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• 제32권3호
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• pp.1055-1058
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• 2011

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2001년도 학술 발표회 진행표 및 논문초록
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• pp.39-39
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• 2001

Many physiological processes of plant cells, such as nutrient uptake, salt tolerance, and cell enlargement, are mediated by ion transports across the plasma membrane. H$^{＋}$-ATPases on both plasma and vacuolar membranes play major roles on active transports and ion channels mediate passive transports of various ions. It has been known that these proteins involved in cellular osmotic regulation and salt tolerance in the salt-accumulated soils.(omitted)

• Bulletin of the Korean Chemical Society
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• 제24권5호
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• pp.552-554
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• 2003

The development of high performance single nanoparticle ion trap (SNIT) apparatus for studying in-situ dynamics of single nanoparticles in controlled environments is described. The performance of SNIT apparatus has been evaluated for 500 nm SiO₂particles. The mass resolution of ~100 ppm and the capability of varying the charge states independently have been demonstrated.

• Bulletin of the Korean Chemical Society
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• 제15권12호
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• pp.1045-1049
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• 1994

A simple and fast ion chromatographic method is developed for the determination of transition metals such as Fe, Cu, Ni, Zn and Co in atmospheric particulates. The method involves acid digestion, on-column preconcentration, and subsequent ion chromatogaphic detection. The precision of the method is less than 3${\%}$ RSD at parts per billion level for the metals studied. No significant interferences are observed. The results obtained with this method agree well with those by ICP-AES.

• Bulletin of the Korean Chemical Society
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• 제10권2호
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• pp.167-171
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• 1989

Kinetic energy release in the fragmentation of tert-butylbenzene molecular ion was investigated using mass-analyzed ion kinetic energy spectrometry. Method to estimate kinetic energy release distribution (KERD) from experimental peak shape has been explained. Experimental KERD was in good agreement with the calculated result using phase space theory. Effect of dynamical constraint was found to be important.

• 공업화학
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• 제21권4호
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• pp.401-404
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• 2010

GDC (Gadolinium doped ceria) 펠렛에 120 keV 및 5 MeV 에너지의 양성자 또는 제논 이온을 주입하였으며, 그 영향을 UV-vis 분광계, SEM 및 XRD를 이용하여 측정하였다. GDC 펠렛은 cubic fluorite 구조를 갖는 조밀한 소결체였으며, 갈색이었던 펠렛이 이온빔을 조사한 후 옅은 검은색을 띠기 시작하였으며, fluence가 증가함에 따라 색도 짙어졌다. XRD 패턴은 이온의 에너지 및 X선의 투과 깊이와 밀접한 관계가 있었으며, 120 keV의 양성자 빔을 조사한 표면 바로 아래층은 이온의 주입으로 결정 구조는 유지한 채 격자 상수가 증가하였다는 것을 관찰하였다.

• Bulletin of the Korean Chemical Society
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• 제31권6호
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• pp.1699-1703
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• 2010

The Schiff base N,N'-bis(pyridin-2-ylmethylene)benzene-1,2-diamine [BPBD] has been synthesized and explored as ionophore for preparing PVC-based membrane sensors selective to the silver ($Ag^+$) ion. Potentiometric investigations indicate high affinity of this receptor for silver ion. The best performance was shown by the membrane of composition (w/w) of ionophore: 1 mg, PVC: 33 mg, o-NPOE: 66 mg and additive were added 50 mol % relative to the ionophore in 1 mL THF. The sensor works well over a wide concentration range $1{\times}10^{-3}$ to $1.0{\times}10^{-7}$ M by pH 6 at room temperature (slope 58.6 mV/dec.) with a response time of 10 seconds and showed good selectivity to silver ion over a number of cations. It could be used successfully for the determination of silver ion content in environmental and waste water samples.