• Bulletin of the Korean Chemical Society
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• 제30권2호
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• pp.315-318
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• 2009

Some particular bound state energies of an electron, under Coulomb potential field, confined in a two-dimensional circle and a three-dimensional sphere are analytically derived. The derivation shows that the electron cannot be bound in a negative energy state when the circle (or sphere) is smaller than a certain critical size. The critical size dependency on the strength of Coulomb potential and the angular momentum of the electron is also analytically derived. This system mimics quantum dots. Therefore the derivation provides new information on a minimum critical size of quantum dots with hydrogenic impurity.

• 대한화학회지
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• 제41권8호
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• pp.427-436
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• 1997

A simple relation exists between electronegativities of cations and their oxidation states and ionic radii. An empirical law is proposed: X = 0.274 z-0.15 z r - 0.01 r+1+${\alpha}$, z being oxidation number, r ionic radius in $\AA$ and ${\alpha}$ a term related to the atomic number. this relation permits to calculate an electronegativity scale covering a large set of electronic and crystallographic situations. An application to the calculation of acid strengths of cations is presented.

• 대한화학회지
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• 제57권2호
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• pp.172-175
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• 2013

We compare the relative usefulness of common basis functions and numerical integration methods in representing complex resonance state encountered in the molecular scattering problem of aluminum dimer electronic predissociation. Specifically, the basis set size and computing CPU times are monitored in order to find the minimum requirement for ensuring the modest accuracy of calculated resonance energies (0.1 $cm^{-1}$) for more than 100 resonance states. The combination of the so-called one-dimensional box eigenfunctions and energy-dependent boundary functions are found to be most efficient if integration is done using the basis set quadrature rules.

• 호남수학학술지
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• 제30권3호
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• pp.411-423
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• 2008

In the field of population dynamics and chemical reaction the possibility or the existence of spatially and temporally nonhomogeneous solutions is a very important problem. For last 50 years or so there have been many results on the pattern formation of chemical reaction systems studying reaction systems with or without diffusions to explain instabilities and nonhomogeneous states arising in biological situations. In this paper we study time-dependent properties of a predator-prey system with functional response and give sufficient conditions that guarantee the existence of stable limit cycles.

• 대한화학회지
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• 제57권6호
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• pp.677-683
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• 2013

A theoretical study of the electronic structures of $TiC_{1-x}$ and $Ti_{1-x}W_xC$ (x = 0, 0.25) is presented. The density of states and crystal orbital overlap population calculations were used to interpret variations of elastic properties induced by carbon vacancies and alloying substitutions. Our results show why the introduction of vacancies into TiC reduces bulk moduli, while W substitution at a Ti site increases the elastic modulus. The effect of the point defects on the bonding in TiC is investigated by means of extended Huckel tight-binding band calculations.

• 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.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
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• pp.319-326
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• 1997

The fire accident cases of several countries such as Korea, Japan, United States, etc., were collected and compared statistically. The trends of fire accidents in several countries will help us establish detailed plans for fire protection and reduce the possible fire accidents in the future. For construction of data base system, the program FADS was developed, which is operable in Windows environment.

• Bulletin of the Korean Chemical Society
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• 제14권1호
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• pp.110-112
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• 1993

Molecular reorientation of oblate symmetric top molecules in the presence of internal rotation is investigated and an analytic expression for the overall reorientational correlation time is obtained. The overall reorientation of the symmetric top is treated by the anisotropic rotational diffusion and the internal rotation is analyzed by employing a model which describes jumps between several discrete states with different lifetimes. The lifetimes thus obtained can be compared with the internal angular momentum correlation time which appears when the internal rotation is treated by a modified extended rotational diffusion model.

• Bulletin of the Korean Chemical Society
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• 제17권10호
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• pp.882-885
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• 1996

The 6a10 and 6b10 vibronic bands in the 12A2-12B2 electronic transition of the emission spectra of the benzyl radical obtained using a high resolution Fourier transform spectrometer are rotationally analyzed. The observed rotational contours were fitted by computer simulated rotational contours, providing determination of the variations, ΔA, ΔB, and ΔC of the rotational constants accompanying the vibronic transitions corresponding to each band. The molecular rotational constants A, B, and C are revised for the upper state and for the two lower states, respectively.

• Bulletin of the Korean Chemical Society
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• 제7권5호
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• pp.376-379
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• 1986

A relatively simple method of locating the saddle point is presented. In this method a single determination of the saddle point location by constrained energy minimizations for points selected on the assumed saddle surface provides us with the structure, location and energy of the TS, the reaction path at the saddle point and characterization as the TS. Some examples were given.