http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
박영호,현상일 한국물리학회 2019 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.75 No.8
We use an eigenmode analysis to investigate normal mode vibrations of hexagonal boron nitride (h-BN) and of various types of graphene and h-BN composites. The vibrational spectrum of pristine h-BN structure was a rescaled one of pristine graphene. The vibrational spectra of graphene and h-BN composites with zigzag and with armchair boundaries were just mixtures of the vibrational spectra of the pristine structures of graphene and h-BN, respectively. The vibrational spectrum of h-BN doped with a graphene quantum dot was similar to that of h-BN, and the vibrational spectrum of graphene doped with a small piece of boron nitride was similar to that of graphene. We found that the resemblance of the vibrational spectra was closely related to the similarities of the lattice structures. Using the amplitude analysis, we were able to identify the eigenmodes of the various composites as motions of nodes in the graphene region or in the h-BN region or at the interfacial boundaries between them.
朴榮浩 釜山水産大學校 1973 釜山水産大學 硏究報告 Vol.13 No.1
In the present study, the effect of storage condition, particularly, high humidity to the changes in chemical components of dried lavers was investigated and some characteristic patterns of the changes were discussed. Dried lavers, Porphyra yezoensis Ueda, were stored at 20� under two different levels of humidity, that were 78% and lower than 7% as relative humidity, respectively. And the content of pigments, organic acids, sugars, and fatty acids were analyzed at 10,25 and 45 day intervals during the storage. Total acidity was also determined. Degradation of chlorophyll a was faster than other pigments such as carotenoids and phycobilins under high humidity. For instance, after 45 day storage, more than two-fold of chlorophll a was retained in low humidified sample compared with that in the case of high humidity whereas a remarkable difference in retention rate of carotenoids or phycobilins was not detected. phycobilins showed high stability under the condition of high humidty, particularly, in phycoerythrin than in phycocyanin. Eight kinds of non-volatile organic acid namely pyruvic, lactic, malonic, fumaric, oxalic, malic, succinic, and citric acid were gas chromatographically identified. The stability of theses acids appeared quite differently by storage humidity. The acids like oxalic, malic, and succinic, did not show an outstanding change under low humidity even after 45 day storage while both oxalic and malic acids remarkably decrased under high humidity and succinic acid contrary increased under the same condition. Citric acid, however, decreased under both cases of humidity. The total amount of volatile acid tended to increase throughout the storage under both high and low humidity, but the rate of increase was relatively greater in case of high humidity than that of low humidity. On the other hand, the same tendedcy was observed in change of total acidity in which the value tended to increase under the high humidity while that remained steady under the low humidity. In the free amino acid composition of dried lavers, alanine,glutamic and aspartic acid were dominant in content whereas such amino acids as methionine, cystine, histididine, comparatively low. It is noteworthy that the content of taurine was tremendously high as an amino acid related compound. During the storage, a significant change in the total amino acid level and individual variation was not detected. In another aspect of storage stability of chemical components, glucose remained with negligible change under both storage conditions and galactose increased rapidly under the high humidity while maintained a steady level under the low humidity. On the contrary, the floridoside decreased rapidly under the high humidity whereas slowly under the low. In the tendecy of strorage stability of fatty acid, tended to decrease in the low humidified material. Under high humidity, ?? acid appeared stable while ?? acid considerably increased. The total fatty acid level which was consisted of 14 kinds of fatty acid seemed to increase in high humidified material and to decrease in the low humidified material.