• 반도체디스플레이기술학회지
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• 제5권4호
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• pp.5-9
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• 2006

The SCT thin films are deposited on Pt-coated electrode($Pt/TiN/SiO_2/Si$) using RF sputtering method with Sr/Ca ratio. The maximum grain of thin films is obtained by ratio of Ca at 15 mol%. The dielectric constant was increased with increasing the ratio of Ca, while it was decreased if the ratio of Ca exceeded over 15 mol%. The dielectric constant changes almost linearly in temperature ranges of $-80{\sim}+90$. All SCT thin films used in this study show the phenomena of dielectric relaxation with the increase of frequency, and the relaxation frequency is observed above 200 kHz. The current-voltage characteristics of SCT thin films showed the increasing leakage current as the measuring temperature increases.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1994년도 추계 학술발표 강연 및 논문 개요집
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• pp.137-137
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• 1994

• 한국재료학회:학술대회논문집
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• 한국재료학회 1992년도 춘계학술발표회
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• pp.93-93
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• 1992

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 1994년도 춘계학술대회강연 및 발표대회 강연및 발표논문 초록집
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• pp.18-19
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• 1994

• 자원환경지질
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• 제25권3호
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• pp.245-258
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• 1992

The variations of certain major and trace elements of the Onjong granite mass was studied on the basis of petrological and geochemical characteristics and compared with those of the Eonyang-Yucheon granite masses in order to investigate the geochemical differences of the granitic rocks in relation to mineralization between Pb-Zn ore district and Pb-Zn-Mo-W ore district in Kyeongsang basin. The Onjong granite mass is classified into granodiorite and monzo-granite, and the Eonyang-Yucheon granite masses into monzo-granite by the Streckeisen's diagram. Between both granite masses there are clear differences in contents of certain major elements and lithophile trace elements. The former have high contents of Ca (2.94%), Mg (1.66%) and Sr (365 ppm), and low contents of K (3.52%), Na (3.51%), Rb (116 ppm), Ba (640 ppm) and Li (18.9 ppm), whereas the latter have high contents of K (4.02%), Na (4.28%), Rb (145 ppm), Ba (695 ppm) and Li (19.3 ppm), and low contents of Ca (1.42%), Mg (0.43%) and Sr (161 ppm). Except for Mo, there are not clear differences in chalcophile trace elements between two granite masses: the Onjong granite mass has higher Mo content (7.1 ppm) lnan that (1.7 ppm) of the Eonyang-Yucheon granite masses, but Pb and Zn contents are similar between the Onjong granite mass (Pb=8.7 ppm, Zn=37.1 ppm) and the Eonyang-Yucheon granite masses (Pb=7.8 ppm, Zn=39.8 ppm). Ca and Sr contents of the Onjong granite mass (Ca> 1.5%, Sr> 270 ppm) are higher than those of the Eonyang- Yucheon granite masses (Ca<1.5%, Sr<270ppm), and Rb/Sr, Rb-Rb/Sr and K-Rb/Sr ratios are clearly distinguishable between the Onjong granite mass(Rb/Sr<0.51, Rb-Rb/Sr>250 and K-Rb/Sr>5.2) and the Eonyang- Yucheon granite masses (Rb/Sr>0.51, Rb-Rb/Sr<250 and K-Rb/Sr<5.0). Thus, variations of certain major and trace elements and ratios are applicable as geochemical index to distinguish the types of mineralization of the ore districts related to the Cretaceous granitic rocks in the Kyeongsang basin.

• The Korean Journal of Physiology and Pharmacology
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• 제3권2호
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• pp.119-125
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• 1999

Mammalian gastric smooth muscles generate spontaneous rhythmic contractions which are associated with slow oscillatory potentials (slow waves) and spike potentials. Spike potentials are blocked by organic $Ca^{2+}-antagonists,$ indicating that these result from the activation of L-type $Ca^{2+}-channel.$ However, the cellular mechanisms underlying the generation of slow wave remain unclear. Slow waves are insensitive to $Ca^{2+}-antagonists$ but are blocked by metabolic inhibitors or low temperature. Recently it has been suggested that Interstitial Cells of Cajal (ICC) serve as pacemaker cells and a slow wave reflects the coordinated behavior of both ICC and smooth muscle cells. Small segments of circular smooth muscle isolated from antrum of the guinea-pig stomach generated two types of electrical events; irregular small amplitude (1 to 7 mV) of transient depolarization and larger amplitude (20 to 30 mV) of slow depolarization (regenerative potential). Transient depolarization occurred irregularly and membrane depolarization increased their frequency. Regenerative potentials were generated rhythmically and appeared to result from summed transient depolarizations. Spike potentials, sensitive to nifedipine, were generated on the peaks of regenerative potentials. Depolarization of the membrane evoked regenerative potentials with long latencies (1 to 2 s). These potentials had long partial refractory periods (15 to 20 s). They were inhibited by low concentrations of caffeine, perhaps reflecting either depletion of $Ca^{2+}$ from SR or inhibition of InsP3 receptors, by buffering $Ca^{2+}$ to low levels with BAPTA or by depleting $Ca^{2+}$ from SR with CPA. They persisted in the presence of $Ca^{2+}-sensitive$ $Cl^--channel$ blockers, niflumic acid and DIDS or $Co^{2+},$ a non selective $Ca^{2+}-channel$ blocker. These results suggest that spontaneous activity of gastric smooth muscle results from $Ca^{2+}$ release from SR, followed by activation of $Ca^{2+}-dependent$ ion channels other than $Cl^-$ channels, with the release of $Ca^{2+}$ from SR being triggered by membrane depolarization.

• 한국재료학회지
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• 제2권4호
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• pp.248-256
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• 1992

본 논문에서는 ATi$O_3$(A=Ca, Sr, Ba) 조성을 갖는 단순 페롭스카이트 구조에서 생성되는 격자결함 구조에 대하여 고찰하였다. 페롭스카이트 구조는 고충전밀도를 갖기 때문에 프렌클 결함은 고려되지 않았다. 쇼트키결함이나, 고유전자결함도 자연적으로 포함된 억셉타 불순물 농도에 비하면 무시할 정도로 적은 양이다. 실제적으로 전기적 특성에 영향을 주는 것은 전하적 결함을 발생하는 aliovalent 불순물이다. 삼성분계이기 때문에 양이온간의 비화학양론이 발생하며 BaTi$O_3$나 SrTi$O_3$에서 수백 ppm이내의 AO나 Ti$O_2$의 용해도가 관찰되나, CaTi$O_3$에서는 상당량의 CaO와 $TiO_2의$ 용해가 가능하다.

• 한국정보통신학회논문지
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• 제11권1호
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• pp.89-94
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• 2007

다양한 기판 온도와 산화 가스 압력 하에서 i-beam 스퍼터링 법으로 BiSrCaCuO 박막을 제작하였다. 기판온도 $T_{sub}$와 산화 가스 압력 $pO_3$를 변화시키며 제작된 Bi2212 및 Bi2223 박막의 생성상도를 작성하였다. Bi2212 조성으로 스퍼터링 하였으나 Bi2212 상 뿐 아니라 Bi2201 상과 Bi2223 상이 모두 생성되었고, Bi2212나 Bi2223 단상은 매우 좁은 온도 영역에서만 형성되었다. 생성 엔탈피의 변화 ${\Delta}{\bar}HO_2$와 생성 엔트로피의 변화 ${\Delta}{\bar}SO_2$에 대한 열역학적인 계산을 통해 Bi2212 단상이 형성된 경우 각각 -260 kJ/mol 및 $-225J/mol{\cdot}K$의 값을 얻었다.

• Current Applied Physics
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• 제18권11호
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• pp.1280-1288
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• 2018

In this work, we pointed out that Sr substitution for Ca leads to modify the magnetic and magnetocaloric properties of $Pr_{0.7}Ca_{0.3-x}Sr_xMnO_3$ compounds. Analyzing temperature dependence of magnetization, M(T), proves that the Curie temperature ($T_C$) increased with increasing Sr content (x); $T_C$ value is found to be 130-260 K for x = 0.0-0.3, respectively. Using the phenomenological model and M(T,H) data measured at several applied magnetic field, the magnetocaloric effect of $Pr_{0.7}Ca_{0.3-x}Sr_xMnO_3$ compounds has been investigated through their temperature and magnetic field dependences of magnetic entropy change ${\Delta}S_m$(T,H) and the change of the specific heat change ${\Delta}C_P$(T,H). Under an applied magnetic field change of 10 kOe, the maximum value of $-{\Delta}S_m$ is found to be about $3J/kg{\cdot}K$, and the maximum and minimum values of ${\Delta}C_P$(T) calculated to be about ${\pm}60J/kg{\cdot}K$ for x = 0.3 sample. Additionally, the critical behaviors of $Pr_{0.7}Ca_{0.3-x}Sr_xMnO_3$ compounds around their $T_C$ have been also analyzed. Results suggested a coexistence of the ferromagnetic short- and long-range interactions in samples. Moreover, Sr-doping favors establishing the short-range interactions.

• 자원환경지질
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• 제45권6호
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• pp.623-641
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• 2012

장군 연-아연-은 광상은 열수교대형 광상이다. 모암변질시 원소 분산을 알아보기 위해 모암, 열수변질대 및 연-아연-은 광맥에서 시료를 채취하였다. 이 광상은 능망간석화작용과 돌로마이트화작용으로 구성된 열수작용이 현저히 인지된다. 모암은 돌로마이트와 석회암이며 구성광물은 방해석, 돌로마이트, 석영, 금운모 및 흑운모 이다. 연-아연-은 광맥과 접촉한 부분에서 관찰되는 능망간석대는 주로 능망간석이 산출되며 소량 방해석, 돌로마이트, 쿠트나호라이트, 유비철석, 황철석, 황동석, 섬아연석, 방연석 및 황석석 등이 산출된다. 연-아연-은 광맥으로부터 멀어짐에 따라 관찰되는 돌로마이트대는 주로 돌로마이트가 산출되고 소량 방해석, 능망간석, 황철석, 섬아연석, 황동석, 방연석 및 황석석 등이 산출된다. 모암변질시 주원소, 미량 및 희토류원소들간의 상관계수는 $Fe_2O_3(T)$/MnO, Ga/MnO 및 Rb/MnO(돌로마이트 및 석회암)가 정의 상관관계를 갖고 MgO/MnO, CaO/MnO, $CO_2$/MnO 및 Sr/MnO(돌로마이트)와 CaO/MnO 및 Sr/MnO(석회암)가 부의 상관관계를 갖는다. 모암변질시 이득원소들은 $Fe_2O_3(T)$, MnO, As, Au, Cd, Cu, Ga, Pb, Rb, Sb, Sc, Sn 및 Zn 이고 손실원소들은 CaO, MgO, $CO_2$ 및 Sr 이다. 따라서 CaO, $CO_2$, $Fe_2O_3(T)$, MgO, MnO, Ga, Pb, Rb, Sb, Sn, Sr 및 Zn 등의 원소들은 모암이 돌로마이트내지 석회암인 열수교대형 광상의 탐사에 지시원소로서 활용될 수 있을 것이다.