• 한국자기학회지
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• 제5권5호
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• pp.880-894
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• 1995

B의 함유량을 6 at% 고정하고 Nd함유량을 3~5 at%로 변화시킨 $\alpha$-Fe기 Nd-Fe-B 합금의 자기특성이 조사 되었다. 급속응고법으로 제조된 $Nd_{x}{(Fe_{0.9}Co_{0.1})}_{90-x}B_{6}Nb_{3}Cu_{1}(x=\;3,\;4,\;5)$ 비정질합금은 열처리에 의하여 초미세결정립으로 결정화하며, Nd의 함유량에 따라 잔류자화 및 보자력이 변한다. x=3의 경우 최적열처리조건에서 $\alpha$-Fe(Co) 부피분율의 증가로 잔류자 화는 증가하나, 보자력은 감소한다. 그러나 Nd 함유량의 증가는 $Nd_{2}{(Fe,\;Co)}_{14}B$ 부피분율의 증가로 인하여 잔류자화는 감소하나 보자력은 향상된다. $640^{\circ}C$, 10 min 열처리조건에서 $Nd_{5}{(Fe_{0.9}Co_{0.1})}_{85}B_{6}Nb_{3}Cu_{1}$의 결정립크기는 약 20 nm이며, 잔류자화, 보자력 및 최대에너지적 은 각각 1.35 T, 219 kA/m (2.75 kOe) 및 $129\;kJ/m^{3}$ (16.2 MGOe)으로 가장 우수하다.

• E2M - 전기 전자와 첨단 소재
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• 제10권6호
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• pp.533-540
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• 1997

The microwave dielectric properties of ((P $b_{1-x}$ C $a_{x}$)Zr $O_3$ and (P $b_{0.63}$,C $a_{0.37-x}$ $M_{x}$)Zr $O_3$(M=Mg,Sr) ceramics were investigated. In (P $b_{1-x}$ C $a_{x}$)Zr $O_3$ (X=0.33~0.40) ceramics, high quality factor and small temperature coefficient of resonant frequency were obtain in (P $b_{0.63}$C $a_{0.37}$)Zr $O_3$with perovskite structure. In the case of (P $b_{0.63}$C $a_{0.37-x}$M $g_{x}$)Zr $O_3$ dielectric constant temperature coefficient of resonant frequency increased and quality factor decreased due to increase of polarization of A-O bonding. When replacing Ca ion with Sr ion with large ion radius, polarization decreased with increased of bonding length and thus dielectric constant and temperature coefficient of resonant frequency decreased.decreased.creased.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 1993년도 추계연구발표회 논문개요집
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• pp.54-55
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• 1993

• Bulletin of the Korean Chemical Society
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• 제6권6호
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• pp.344-347
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• 1985

Perovskite type oxides of $SrTiO_3,SrZrO_3,and\;SrTi_{1-x}Zr_xO_3$ have been systematically synthesized at $1250^{\circ}C$and $1550^{\circ}C$ with specimens containing additions of up to x=0.9 of zirconium by solid state reactions and characterized by X-ray diffraction. X-ray diffraction studies showed that the compound $SrTi_{1-x}Zr_xO_3$ has cubic structure. The lattice paramters of $SrTi_{1-x}Zr_xO_3$ solid solutions obey the Vegard's law and fairly large increase in volume can acompany the formation of this solution with increasing Zr content(X). Assuming the lattice constants of perovskite type compounds $A(B_{1-x}B'_x)O_3$where $B_{1-x}B'_x$ is $Ti_{1-x}Zr_x$, to be a linear function of the ionic radii of B and B' ions, the disordered ion pair of $Ti^{4+}$and $Zr^{4+}$ was verified from the lattice constants of a series compounds varying x=0,0.05, 0.25, 0.5, 0.75, 0.9, and 1.0 with known isovalent pairs.

• Molecules and Cells
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• 제43권12호
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• pp.1023-1034
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• 2020

Complement fragment iC3b serves as a major opsonin for facilitating phagocytosis via its interaction with complement receptors CR3 and CR4, also known by their leukocyte integrin family names, αMβ2 and αXβ2, respectively. Although there is general agreement that iC3b binds to the αM and αX I-domains of the respective β2-integrins, much less is known regarding the regions of iC3b contributing to the αX I-domain binding. In this study, using recombinant αX I-domain, as well as recombinant fragments of iC3b as candidate binding partners, we have identified two distinct binding moieties of iC3b for the αX I-domain. They are the C3 convertase-generated N-terminal segment of the C3b α'-chain (α'NT) and the factor I cleavage-generated N-terminal segment in the CUBf region of α-chain. Additionally, we have found that the CUBf segment is a novel binding moiety of iC3b for the αM I-domain. The CUBf segment shows about a 2-fold higher binding activity than the α'NT for αX I-domain. We also have shown the involvement of crucial acidic residues on the iC3b side of the interface and basic residues on the I-domain side.

• 한국자기공명학회논문지
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• 제9권1호
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• pp.61-66
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• 2005

$^{11}B MAS NMR$ spectra of binary glass system $xV_2O5-B_2O_3$ and ternary glass system $xV_2O5-B_2O_3-yNa_2O$ (x = $V_2O_5 mol%/$B_2O_3$ mol%, y = $Na_2O$ mol$/$B_2O_3$ mol%) were acquired. $BO_3$ units are dominant components in the spectra of $xV_2O_5-B_2O_3$glass systems while both $BO_3$ and $BO_4$ unit appear in comparable amounts in the spectra of $xV_2O_5-B_2O_3-yNa_2O$ glass systems. More $BO_3$ units were monitored for higher $V_2O_5$ contents while more $BO_4$ unit for higher $Na_2O$ contents. Quadrupole parameters such as $e^2qQ$ and $\eta$ obtained form spectral simulation indicate that $e^2qQ$ has a maximum value at x = y 1 and $\eta$ decreases and increases as x or y grows, respectively. Our results suggest that $V_2O_5$ and $Na_2O$ play opposite roles in the ternary glasses.

• 한국환경보건학회지
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• 제36권4호
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• pp.313-322
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• 2010

The aim of this research was to apply experimental design methodology to optimization of conditions of electrochemical oxidation of Rhodamine B (RhB) and N, N-Dimethyl-4-nitrosoaniline (RNO, indicative of the OH radical). The reactions of electrochemical oxidation of RhB degradation were mathematically described as a function of the parameters of current ($X_1$), NaCl dosage ($X_2$) and pH ($X_3$) and modeled by the use of the central composite design. The application of response surface methodology (RSM) yielded the following regression equation, which is an empirical relationship between the removal efficiency of RhB and RNO and test variables in a coded unit: RhB removal efficiency (%) = $94.21+7.02X_1+10.94X_2-16.06X_3+3.70X_1X_3+9.05X_2X_3-{3.46X_1}^2-{4.67X_2}^2-{7.09X_3}^2$; RNO removal efficiency (%) = $54.78+13.33X_1+14.93X_2- 16.90X_3$. The model predictions agreed well with the experimentally observed result. Graphical response surface and contour plots were used to locate the optimum point. The estimated ridge of maximum response and optimal conditions for the RhB degradation using canonical analysis was 100.0%(current, 0.80 A; NaCl dosage, 2.97% and pH 6.37).

• Bulletin of the Korean Chemical Society
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• 제32권6호
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• pp.2045-2050
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• 2011

Using first principles density functional theory the formation energies of various binary compounds of lithium graphite and its homologues were calculated. Lithium and graphite react to form $Li_1C_6$ (+141 mV) but not form $LiC_4$ (-143 mV), $LiC_3$ (-247 mV) and $LiC_2$ (-529 mV) because they are less stable than lithium metal itself. Properties of structure and reaction potentials of $C_5B$, $C_5N$ and $B_3N_3$ materials as iso-structural graphite were studied. Boron and nitrogen substituted graphite and boron-nitrogen material as a iso-electronic structured graphitic material have longer graphene layer spacing than that of graphite. The layer spacing of $Li_xC_6$, $Li_xC_5B$, $Li_xC_5N$ materials increased until to x=1, and then decreased until to x=2 and 3. Nevertheless $Li_xB_3N_3$ has opposite tendency of layer spacing variation. Among various lithium compositions of $Li_xC_5B$, $Li_xC_5N$ and $Li_xB_3N_3$, reaction potentials of $Li_xC_5B$ (x=1-3) and $Li_xC_5$ (x=1) from total energy analyses have positive values against lithium deposition.

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2000년도 춘계총회,특별강연,심포지움,연구발표회
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• pp.117.2-117.2
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• 2000

• 한국자기학회지
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• 제9권3호
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• pp.154-158
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• 1999

Nd 함유량을 2~6at.%로 변화시킨 $\alpha$-(Fe, Co)-B-Nb-Cu 초미세결정립합금의 미세조직 및 자기특성을 조사하였다. 급속응고된 Ndx(Fe0.9Co0.1)90-xB6Nb3Cu1(2$\leq$x$\leq$6, 1at.% 간격) 합금은 x=3 이상에서 비정질상으로 제조되었다. 제조된 비정질합금은 열처리에 의해 $\alpha$-(Fe, Co) 및 Nd2(Fe, Co)14B1상으로 구성된 초미세결정립합금으로 결정화 되었다. 최적열처리조건에서 잔류자화는 Nd의 증가에 따라 감소하며, x=3에서 1.55T로 최대 값을 나타내었다. 보자력은 Nd함유량 증가에 따라 직선적으로 증가하여 x=6에서 4.6kOe이었으며, 최대에너지적은 10.6MGOe였다.