검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 15

        1.
        2013.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Cu2ZnSn(Sx,Se1-x)4 (CZTSSe) thin films were prepared by sulfurization of evaporated precursor thin films. Precursor was prepared using evaporation method at room temperature. The sulfurization was carried out in a graphite box with S powder at different temperatures. The temperatures were varied in a four step process from 520˚C to 580˚C. The effects of the sulfurization temperature on the micro-structural, morphological, and compositional properties of the CZTSSe thin films were investigated using X-ray diffraction (XRD), Raman spectra, field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The XRD and Raman results showed that the sulfurized thin films had a single kesterite crystal CZTSSe. From the FE-SEM and TEM results, the Mo(Sx,Se1-x)2 (MoSSe) interfacial layers of the sulfurized CZTS thin films were observed and their thickness was seen to increase with increasing sulfurization temperature. The microstructures of the CZTSSe thin films were strongly related to the sulfurization temperatures. The voids in the CZTSSe thin films increased with the increasing sulfurization temperature.
        4,000원
        2.
        2010.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        For the aim of low-temperature co-fired ceramic microwave components, sintering behavior and microwave properties (dielectric constant , quality factor Q, and temperature coefficient of resonant frequency ) are investigated in [BCZN] ceramics with addition of . The specimens are prepared by conventional ceramic processing technique. As the main result, it is demonstrated that the additives () show the effect of lowering of sintering temperature and improvement of microwave properties at the optimum additive content. The addition of 0.25 wt% lowers the sintering temperature to utilizing liquidphase sintering and show the microwave dielectric properties (dielectric constant = 75, quality factor = 572 GHz, temperature coefficient of resonance frequency ). The estimated microwave dielectric properties with addition (increase of , decrease of , shift of to negative values) can be explained by the observed microstrucure (sintered density, abnormal grain structure) and possibly high-permittivity (BZN) phase determined by X-ray diffraction.
        4,000원
        4.
        2017.05 서비스 종료(열람 제한)
        Background : This study of investigate the quality characteristics of Korean Dioscoreae Rhizoma by species and various processing methods. We used two types of species D. Rhizoma, which were the long type shape of D. batatas and short type shape of D. japoninca, respectively. Methods and Results : The reaction of D. Rhizoma with acetic acid and iodine showed light blue to blue colours, respectively. When compared with loss of drying between two species, the long type species was about 2% more higher than that of short type of species. When compared with processing methods, the both steamed and dried samples was more higher 2.0 - 3.0% than that of non-steamed samples. The contents of acid-insoluble ash samples with peel was relatively higher than that of samples containing no-peel. The results of TLC analysis also showed the same Rf and colours when compared with the standard of D. Rhizoma. However, both dried sample with peel (DWP) showed more clear spot than those of dried sample except peel (DEP) and both steamed and dried sample except peel (SDEP). Conclusion : We sincerely hope that this study will be contributed to the standardization and quality control of korean herbal medicines.
        5.
        2016.12 KCI 등재 서비스 종료(열람 제한)
        Background: Leonurine is a the aerial part of Leonurus japonicus Houttuyn, which has been used as a traditional medicines and is registered in the Korean Pharmacopoeia.Methods and Results:In the present study we performed a heavy metals and thin layer chromatography and measured loss on drying, as well as the contents of total ash, acid-insoluble ash, ethanol soluble compounds, and leonurine, using 15 domestically collected L. japonicus samples. The methods were performed according to the ‘crude drugs test of the general test, processes and apparatus’, published by MFDS, Korea (2014). The purity test (heavy metals) indicated that levels of Pb and Hg were 0.35 - 3.64, and 0.001 ppm, respectively, whereas the levels of As and Cd were undetectable, and stachydrine was identified by thin layer chromatography (Rf : 0.15). We found that 5.93 - 10.62% (average: 8.58 ± 1.8%) of the sample mass was lost during drying, and the contents of total ash, acid-insoluble ash, ethanol soluble compounds, and leonurine were 7.87 - 10.84% (average: 9.62 ± 0.82%), 0.99 - 1.76% (average: 1.38 ± 0.24%), 16.70 - 23.11% (average: 19.49 ± 2.14%) and 0.04 - 0.17% (average: 0.11 ± 0.04%) respectively. In addition, HPLC profiling detected leonurine (5.94 min), rutin (16.43 min) and myricetin (26.78 min).Conclusions:We hope that this the rusult of the present study will contribute to the standardization and quality control of Korean herbal medicines.