• 제목/요약/키워드: C Band

검색결과 3,069건 처리시간 0.035초

EPR SPECTRA OF Mn ION WITH TWO PHASES IN THE Y-Ba-Cu-Mn-O HIGH Tc SUPERCONDUCTOR

  • Kim, Seon-Ok;Rudowicz, Czeslaw;Lee, Soo-Hyung;Yu, Seong-Cho
    • 한국자기학회지
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    • 제5권5호
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    • pp.782-785
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    • 1995
  • In this paper, $Mn^{2+}$ ion was doped in Y-Ba-Cu-O as an EPR probe. The following samples were prepared by conventional solid-state reaction method : $YBa_{2}Cu_{2.96}Mn_{0.04}O_{7-\delta}$ (MN-I), annealed $YBa_{2}Cu_{2.96}Mn_{0.04}O_{7-\delta}$ (AMN) and $YBa_{2}Cu_{2.94}Mn_{0.06}O_{7-\delta}$ (MN-II). AMN sample was obtained from MN-I by annealing for 1 hr under the Ar gas atmosphere at $600^{\circ}C$. X-band (~9.05 GHz) EPR spectra were measured from 103 K to room temperature by employing a JES-RE3X spectroscopy with a $TE_{0.11}$ cylindrical cavity and 100 kHz modulation frequency. In MN-I we have observed only the $Cu^{2+}$ signal. The fact that no $Mn^{2+}$ signal was observed, in spite of $Mn^{2+}$ being a very sensitive EPR probe, indicates that most likely isolated $Mn^{2+}$ ions don't exist in the MN-I sample. Most probably $Mn^{2+}$ ions in the MN-I sample interact antiferromagnetically and hence are EPR silent. The AMN spectra of at room temperature and 103 K indicate not only the $Cu^{2+}$ signal but also an extra signal, which increases with decreasing temperature. It is suggested that the extra signal originates from Mn ions that were antiferromagnetically coupled before the annealing process. In MN-II, from 103 K to room temperature, also, the extra signal was observed together with the $Cu^{2+}$ signal. The extra signal in MN-II, however, decreases with decreasing temperature and nearly disappears at 103 K. The signal originates from Mn ions in impurity phases that include $Mn^{2+}$ ions. We suppose that there exist at least two $Mn^{2+}$ doped phases in Y-Ba-Cu-O. The $Mn^{2+}$ signal of one phase is undectable at all temperature and that of another phase decreases with decreasing temperature and disappears around 103 K.

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Ru-Co가 치환된 M-형 육방정 페라이트(BaFe12-2xRuxCoxO19)의 자기적 성질 및 전파흡수 특성 (Magnetic and Microwave Absorbing Properties of M-type Hexagonal Ferrites Substituted by Ru-Co(BaFe12-2xRuxCoxO19))

  • 조한신;김성수
    • 한국자기학회지
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    • 제18권4호
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    • pp.136-141
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    • 2008
  • Ru-Co가 복합 치환된 M-type Ba-ferrite($BaFe_{12-2x}Ru_xCo_xO_{19}$)의 치환량 x의 변화에 따른 자기적 특성과 전파흡수 특성에 관해 조사하였다. 기존의 Ti-Co를 치환시킨 경우보다 적은 양의 치환(x=0.3)으로 면내 자기이방성을 보이는 낮은 보자력($H_c$)과 높은 포화자화($M_s$) 값을 얻을 수 있었다. 따라서 Ru-Co 치환량 조절에 의해 GHz 대역에서 자연공명주파수의 조절이 가능하였다. 소결체 및 복합체에서 흡수 주파수 대역은 보자력이 증가할수록 고주파 대역으로 이동한다. 복합체에서 페라이트 혼합량이 증가함에 따라 복소투자율과 복소유전율의 값이 증가하기 때문에 정합주파수는 저주파 대역으로 이동한다. 이러한 특성들을 이용하여 순수한 M-형 육방정 페라이트에 Ru-Co의 치환량, 복합체에서 페라이트 분말의 혼합량, 그리고 흡수체의 두께의 제어를 통하여 GHz 주파수 대역에서 양호한 전자파 흡수체, 노이즈 감쇠재의 제조가 가능함을 제시할 수 있다.

비 마비 측과 마비 측에 적용한 탄력밴드를 결합한 고유수용성 신경근 촉진법 하지패턴이 만성 뇌졸중 환자의 균형에 미치는 영향 (Effect of Non-paralyzed side and Paralyzed side of Elastic Band Combined with Proprioceptive Neuromuscular Facilitation Lower Extremity Patterns on Balance in Chronic Stroke Patients)

  • 이영민;함민식;김택수
    • PNF and Movement
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    • 제13권4호
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    • pp.181-188
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    • 2015
  • Purpose: This study aimed to examine the effects of proprioceptive neuromuscular facilitation (PNF) lower extremity patterns combined with elastic bands applied to stroke patients diagnosed with hemiplegia through self-training using the non-paralyzed side approach and the paralyzed side approach, and to investigate the differences in the effects. Methods: Nine chronic stroke patients who were being treated not more than twice a week at H, K, R, and C hospitals located in Gangwon-do, performed self-training for 16 minutes, two times per day for four weeks between August and October 2015. The subjects' balance ability was measured using the Tetrax stability index, the weight distribution index, the Berg Balance Scale (BBS), and the Timed Up and Go (TUG) test before the experiment and four weeks later. Among the statistical methods, paired t-tests were conducted for intra-group comparison of the measurements taken before and after the experiment, and independent t-tests were conducted for inter-group comparison of the ex post facto values. The statistical significance level was set to 0.05. Results: When the lower extremity patterns were applied to the non-paralyzed side group and the paralyzed side group, significant intra-group differences were observed for the Tetrax stability index, the weight distribution index, the Berg Balance Scale (BBS), and Timed Up and Go (TUG) tests (p<0.05); however, the inter-group comparisons showed no significant differences. Conclusion: The non-paralyzed side approach was found to be easy for patients to participate in and it also affected the patients' paralyzed side. Although the paralyzed side approach produced good exercise effects in a short period of time, it could result in adverse effects, such as a decrease in motivation and self-confidence. Therefore, these approaches are considered to be more effective when they are selectively applied depending on the purpose of the intervention and the degree of a patients' participation.

Chinese Hamster Lung Cell을 이용한 in vitro 소핵시험의 세포질 최적화 연구 (Study on Optimization of Cytoplasm Conditions for In Vitro Micronucleus Test Using Chinese Hamster Lung Cells)

  • 백민경;김아름누리;신혜림;전경미;박경훈;류지혁;문병철
    • 한국환경농학회지
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    • 제37권3호
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    • pp.229-234
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    • 2018
  • In vitro 소핵시험(vitMNT)은 유전독성의 유망한 대체시험법 중 하나로, OECD에서 TG로 채택되어 화학물질의 등록에 사용되고 있다. 본 시험에서는 CHL cell을 사용한 vitMN test에서 소핵을 판별하기 위한 최적화된 세포질 조건을 찾고자 하였으며, 양성대조물질로 MMC와 Col을 사용하고 세포 염색을 위해 giemza 용액을 사용하였다. 시험결과, 세포현탁을 위해 사용되는 고정액의 acetic acid의 농도는 1%로 하는 것이 band의 두께와 세포질의 퍼짐성 측면에서 적당하였다. 또한 세포의 깨짐을 최소화하는 최종 고정액의 적하시간은 현탁 후 1~4시간이었다. 이러한 결과는 vitMNT에서 소핵관찰의 신속성, 용이성 및 정확성을 확보하는데 도움이 될 것이다.

Cordycepin 강화 한우고기 생산에 관한 연구 II. 곡립기주 동충하초 균사체 급여가 한우고기내 cordycepin 축적에 미치는 영향 (Development of cordycepin fortified meat production in Hanwoo steers II. Effects of mycelia of Cordyceps militaris cultured from grains on cordycepin deposition in muscles of finishing Hanwoo steers)

  • 김완영;이성훈;김도형;이장형;노환국;황진호;여준모
    • 현장농수산연구지
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    • 제11권1호
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    • pp.53-61
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    • 2009
  • 본 연구는 개발된 밀리타리스 동충하초 균사체를 비육후기 한우에 사료경제적인 한계의 최고점에서 일정기간 급여하여 균사체내에 존재하는 cordycepin이 한우 조직내에 존재하는 지와 혈중 항산화활성의 증가를 확인하기 위하여 수행하였다. 본 연구는 비육후기 거세한우 4두를 공시하여 대조구와 처리구 각각 2두씩 배치하고, 처리구의 균사체 첨가수준은 사료섭취량의 1%로 정하여 80일간 사양하였다. 사양후 도축하여 근육(후지)을 취하여 이들내 cordycepin을 TLC상에서 전개하고, 혈액을 채취하여 혈장내 항산화효소인 GSH-Px활성을 조사하였다. 본 연구에서 얻어진 결과를 살펴보면, 종료체중, 건물섭취량, 중체량은 대조구 및 밀리타리스 동충하초 균사체급여군간에 유의한 차이가 나타나지 않았다. 혈장내 GSH-Px활성은 처리구가 15.70 unit로서 대조구의 9.23 unit보다 높은 항산화도를 나타내었으나, 통계적으로 유의한 차이는 나타나지 않았다. 근육내 cordycepin의 전이는 곡립 밀리타리스 동충하초 균사체 급여군에서 TLC상 band가 확인되었다. 이상의 결과로부터 밀라티리스 동충하초 균사체를 비육후기 거세우에 급여하였을 때 비록 유의성은 나타나지 않았지만, 항산화 기능이 어느 정도 있는 것으로 확인되었고, 처리군의 근육에서 cordycepin이 확인되었다. 따라서, 곡립 밀리타리스 동충하초 균사체를 한우에 급여하면 조직 내의 cordycepin의 전이가 가능한 것으로 사료된다.

Nature of the Interfacial Regions in the Antiferromagnetically-coupled Fe/Si Multilayered Films

  • Moon, J.C.;Y.V. Kudryavtsev;J.Y.Rhee;Kim, K.W.;Lee, Y.P.
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2000년도 제18회 학술발표회 논문개요집
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    • pp.174-174
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    • 2000
  • A strong antiferromagnetic coupling in Fe/Si multilayered films (MLF) had been recently discovered and much consideration has been given to whether the coupling in the Fe/Si MLF system has the same origin as the metal/metal MLF. Nevertheless, the nature of the interfacial ron silicide is still controversial. On one hand, a metal/ semiconductor structure was suggested with a narrow band-gap semiconducting $\varepsilon$-FeSi spacer that mediates the coupling. However, some features show that the nature of coupling can be well understood in terms of the conventional metal/metal multilayered system. It is well known that both magneto-optical (MO) and optical properties of a metal depend strongly on their electronic structure that is also correlated with the atomic and chemical ordering. In this study, the nature of the interfacial regions is the Fe/Si multilayers has been investigated by the experimental and computer-simulated MO and optical spectroscopies. The Fe/Si MLF were prepared by rf-sputtering onto glass substrates at room temperature with the number of repetition N=50. The thickness of Fe sublayer was fixed at 3.0nm while the Si sublayer thickness was varied from 1.0 to 2.0 nm. The topmost layer of all the Fe/Si MLF is Fe. In order to carry out the computer simulations, the information on the MO and optical parameters of the materials that may constitute a real multilayered structure should be known in advance. For this purpose, we also prepared Fe, Si, FeSi2 and FeSi samples. The structural characterization of Fe/Si MLF was performed by low- and high -angle x-ray diffraction with a Cu-K$\alpha$ radiation and by transmission electron microscopy. A bulk $\varepsilon$-FeSi was also investigated. The MO and optical properties were measured at room temperature in the 1.0-4.7 eV energy range. The theoretical simulations of MO and optical properties for the Fe/Si MLF were performed by solving exactly a multireflection problem using the scattering matrix approach assuming various stoichiometries of a nonmagnetic spacer separating the antiferromagnetically coupled Fe layers. The simulated spectra of a model structure of FeSi2 or $\varepsilon$-FeSi as the spacer turned out to fail in explaining the experimental spectra of the Fe/Si MLF in both intensity and shape. Thus, the decisive disagreement between experimental and simulated MO and optical properties ruled out the hypothesis of FeSi2 and $\varepsilon$-FeSi as the nonmagnetic spacer. By supposing the spontaneous formation of a metallic ζ-FeSi, a reasonable agreement between experimental and simulated MO and optical spectra was obtained.

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청송군 송강리 석회규산염암류의 지질구조 (Geological Structures of the Limesilicates in the Songgang-ri, Cheongsong-gun, Korea)

  • 강지훈
    • 암석학회지
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    • 제27권3호
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    • pp.139-151
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    • 2018
  • 경상분지 영양소분지 남서 경계부의 영남육괴 소백산지구에 위치하는 청송군 송강리지역은 시대미상의 변성암류(호상편마암, 화강암질편마암, 석회규산염암류)와 이를 관입하는 시대미상의 화성암류(화강편마암)로 구성되어 있다. 본 논문은 송강리 송강마을의 동측에 흐르는 용전천 하안을 따라 약 170 m 노출된 지질노두에서 중첩 변형된 암석구조의 기하학적 운동학적 특성과 이들 변형구조의 선후관계로부터 송강리지역 구성암류의 변형사를 연구하였다. 송강리 지질노두에서 변형 및 관입 시기를 서로 달리하는 3회(Fn, Fn+1, Fn+2)의 습곡작용과 3회(Dk-I, Dk-II, Dk-III)의 산성암맥들의 관입작용 그리고 1회의 단층운동이 인지되고, 이들은 적어도 다섯 번의 변형단계(Dn, Dn+1, Dn+2, Dn+3, Dn+4)를 걸쳐 형성되었다. Dn 변형은 광역엽리를 형성시키는 Fn 습곡작용으로 인지된다. Dn+1 변형은 (동)북동-(서)남서 방향의 압축응력에 의해 전기단계에 (동)북동 방향의 Dk-I 암맥을 관입시켰으며, 후기단계에 북서 방향의 Fn+1 습곡을 형성시켰다. 주요 변형된 암석구조로는 밀착, 등사, 층간습곡, 부딘구조, 부딘의 ${\sigma}$-형 내지 ${\delta}$-형 구조, 비대칭습곡, C' 전단띠 등이 있다. Dn+2 변형은 (북)북서-(남)남동 방향의 압축응력에 의해 전기단계에 북서 방향의 Dk-II 암맥을 관입시켰으며, 후기단계에 북동 방향의 Fn+2 습곡을 형성시켰다. 주요 변형된 암석구조로는 개방습곡과 습곡된 부딘구조 등이 있다. Dn+3 변형은 Dk-I과 Dk-II의 암맥들과 Fn+2 습곡축면을 절단하는 Dk-III의 암맥을 관입시켰다. Dn+4 변형은 상반이 남남동 방향으로 이동하는 북북동 방향의 좌수향 역이동성 사교이동 단층을 형성시켰다. 송강리 지질노두에서 인지되는 이러한 다섯 번의 변형작용은 송강리지역 뿐만 아니라 보다 광역지역 구성암류의 분포 및 지질구조와 밀접한 관련이 있음을 고려해 볼 때, 본 연구결과는 영남육괴의 소백산지구와 경상분지의 경계부와 그 주변부의 구성암류가 경험한 지질구조 및 그 발달사를 규명하고 이해하는데 매우 중요한 연구자료로 활용될 것으로 기대된다.

토끼의 혈청 콜레스테롤 함량에 미치는 지방의 포화도에 관한 연구 (Studies on the effect in degree of saturation of fats on serum cholesterol level in the rabbit)

  • 남현근;성하진;장인애
    • 한국식품영양과학회지
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    • 제10권1호
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    • pp.27-37
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    • 1981
  • The effect in degree of saturation and unsaturation of dietary added oils on the serum cholesterol level in the rabbit was studied for a kperiod of 4 weeks using isocalories and isonitrogenous diets. The subject rabbits were divided into 10 feeding groups such as control-1 (Basal diet only), A group (Basal+sesame oil), B group (Basal+perilla oil), C group (Basal+soybean oil), D group (Basal+rice bran oil), Control-A(Basal+casein), A-1 group (Basal+sesame oil+ casein), B-1 group (Basal+perilla oil+casein), C-1 group (Basal+soybean oil+casein) and D-1 group (Basal+rice bran oil+casein). The results are summarized as follows: 1. Body weight gains per week of the perilla oil fed group were higher than anyother groups during the experimental period. 2. Food efficiency ratios for the group of perilla oil fed were 1.041, 0.781, 0.520 and 0.431 for 1st, 2nd, 3rd and 4th week, respectively. 3. In the group of perilla oil and Casein fed, food efficiency ratios for the experimental period were 0.887, 0.823, 0.489 and 0.437 for 1st, 2nd, 3rd and 4th week, respectively. 4. It is investigated that the food efficiency ratio for perilla oil fed groups was higher than the group of perilla oil and casein fed. 5. Calorie efficiency ratios for perilla oil fed group were 0.018, 0.036, 0.024 and 0.020 for 1st, 2nd, 3rd and 4th week, respectively. Calorie efficiency ratios for perilla oil and casein fed group were 0.028, 0.030, 0.024 and 0.020 for 1st, 2nd, 3rd and 4th week, respectively. 6. Serum cholesterol was 72.8mg% for the group of perilla oil (6gr) and casein(6gr) fed, and liver cholesterol was 460.5mg% for the same group. 7. Serum triglyceride was 130.7mg% for the group of perilla oil (6gr) and casein (6gr) fed. 8. Blood glucose was 40.34mg% for control-l and 96.4mg% for control-A, respectively. Blood glucose was 120.4mg% for group Band 1l0.7mg% for group B-1, respectively. 9. The degree of saturation/unsaturation for perilla oil (SFA/USFA) was 7.8/92.2 and nonessential fatty acid/essential fatty acid(NEFA/EFA) was 26.3/73.7. In this conditions, serum and liver cholesterol was lower than anyother conditions for this experimental period. 10. For the perilla oil fed group, serum cholesterol was 105.5mg% for pleic acid/linoleic acid(18.5/58.5) and 72.8mg% for linoleic acid/linolenic acid(15.2/58.5). In this group, triglyceride was 132.5mg% for oleic acid/linoleic acid and 130.5mg% for linoleic acid/linolenic acid. 11. There are positive correlation between serum cholesterol and saturated fatty acid $({\gamma}=0.78)$, and unessential fatty acid $({\gamma}=0.41)$. There are negative correlation between serum cholesterol and unsaturated fatty acid$({\gamma}=-0.78)$ and essential fatty acid$({\gamma}=0.77)$, respectively. 12. The range of most effective diet for serum cholesterol level lowering was nonessential fatty acid/essential fatty acid(26.3/73.7), saturated fatty acid/unsaturated fatty acid(7.8/92.2) and added oil (6gr)/added casein protein(6gr).

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Bacterial Community Dynamics during Swine In vitro Fermentation Using Starch as a Substrate with Different Feed Additives for Odor Reduction

  • Alam, Md.J.;Jeong, C.D.;Mamuad, L.L.;Sung, H.G.;Kim, D.W.;Cho, S.B.;Lee, K.;Jeon, C.O.;Lee, Sang-S.
    • Asian-Australasian Journal of Animal Sciences
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    • 제25권5호
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    • pp.690-700
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    • 2012
  • The experiment was conducted by in vitro fermentation and bacterial community analysis to investigate the reduction of odorous compounds in response to the use of feed additives (FA) during carbohydrate overload in growing pigs. Soluble starch at 1% (control) and various FA at 0.1% Ginseng meal (FA1); Persimmon leaf (FA2); Gingko nut (FA3) and Oregano lippia (FA4) were added to fecal slurry and incubated anaerobically for 12 and 24 h. In vitro parameters and microbial diversity of the dominant bacteria following fermentation were analyzed using Denaturing Gradient Gel Electrophoresis (DGGE), band cloning and sequencing of the V3 region. Results showed that total gas production increased with the advancement of incubation (p<0.05). pH values of FAs and control groups were decreased except the FA4 group which increased somewhat from 12 to 24 h (p<0.05). Ammonia nitrogen ($NH_3$-N) and $H_2S$ gas concentrations were comparatively lower in both stages in FA4 treatment than in the other groups (p<0.05). Hence, $NH_3$-N concentrations in liquid phases were increased (p<0.05) from 12 to 24 h, but the trend was lowest in FA4 than in the other groups at both stages. The total VFA production was comparatively lower and butyrate levels were moderate in FA4 group than in the the other groups during both stages (p<0.05). Indirect odor-reducing compounds such as $NO_2$, $NO_3$ and $SO_4$ concentrations were higher in the FA4 and FA3 than in the other groups at 24 h (p<0.05). After fermentation, ten dominant bands appeared, six of which appeared in all samples and four in only the FA4 treated group. The total number of DGGE bands and diversity was higher in the FA4-group compared to other groups. Additionally, similarity indices were lowest (71%) in the FA4, which represented a different bacterial community compared with the other groups. These findings indicate that $NH_3$-N, $H_2S$ and VFA production was minimal, and pH was also better in the FA4 group than in the other groups. Furthermore, the conversion of odor-reducing indirect compounds or their intermediates was higher in the FA4 group in compared to the other groups. FA4 group generated less odorous products and more indirect products by in vitro fermentation at 24 h, and their microbial pattern appeared to differ from that of the other groups. These findings suggest that this particular FA could change the microbial population, which may have a beneficial effect on odor reduction. It is recommended that the oregano lippia may be supplied to growing pigs as FA along with excess carbohydrate sources to reduce the production of odorous compounds.

$Tb^{3+}$ 와 Eu^{3+}$로 활성화시킨${Al_3}{GdB_4}{O_{12}}$ 형광체의 발광 특성 (Photoluminance Properties of ${Al_3}{GdB_4}{O_{12}}$ Phosphors Activated by $Tb^{3+} and Eu^{3+}$)

  • 김기운;강세선;이임렬
    • 한국재료학회지
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    • 제10권1호
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    • pp.49-54
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    • 2000
  • PDP용의 새로운 녹색 $Al_3GdB_4O_{12}:Tb^{3+} 형광체와 Al_3GdB_4O_{12}:Eu_{3+}$ 적색형광체를 제조한 후 광특성을 분석하였다. 또한 이들 형광체의 발광특성을 상용품인 $Zn_2SiO_4:Mn^{2+}$ 녹색 형광체와 $(Y,Gd)BO_3: Eu^{3+}$ 적색의 PDP 형광체와 상호 비교하였다. 형광체는 $1150^{\circ}C$에서 4시간 동안 공상 반응으로 제조하였다. 147nm의 진공자외선 조사시 $Al_3GdB_4O_{12}:Tb^{3+}$(15mol%) 녹색 형광체의 발광휘도는 상용품 $Zn_2SiO_4: Mn^{2+}$ 보다 증가하였으나 색좌표는 상대적으로 저하되었다. 한편 $Al_3GdB_4O_{12}:Eu^{3+}$(15mol%) 적색 형광체의 발광 휘도는 상용품$(Y,Gd)BO_3: Eu^{3+}$ 보다 작았으나 CIE 색좌표는 일부 개선되었다. $Al_3GdB_4O_{12}$ 형광체는 $\lambda=160nm$에서 모체 흡수에 의한 강한 여기밴드가 있으며, 진공자외선 영역에서 $Al_3GdB_4O_{12}:Tb^{3+}$ 녹색형광체의 여기강도는 $Zn_2SiO_4: Mn^{2+}$ 보다 컸으나 $Al_3GdB_4O_{12}:Eu^{3+}$ 적색 형광체의 여기강도는 $(Y,Gd)BO_3: Eu^{3+}$ 보다는 작았다.

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