• YAKHAK HOEJI
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• v.28 no.2
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• pp.69-77
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• 1984

Anti-coagulant activities of 25 species of medicinal plants which have been related to "blood" in ethnobotany, were evaluated by plasma recalcification time test. Among these, Artemisiae Herba showed the strongest activity. Its anti-clotting component was purified by using DEAE-cellulose, Sephadex G-75, and Sephadex LH-20 column chromatography. Its active compound has an average molecular weight of approximately $10^{4}$ and it was turned to be an acidic polysaccharide composed of galacturonic acid and rhamnose (7 : 2) by chemical analysis and spectral data.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.229-230
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• 2015

The results of spectral studies of the CTTS type young star RY Tau with spectrograms of the ultraviolet and the visual ranges are presented. We show the first detection of periodic variability of the emission line intensities in UV and visual ranges with a period of 23 days.

• YAKHAK HOEJI
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• v.22 no.2
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• pp.83-86
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• 1978

A colorless sublime needles (A), $C_{10}H_{10}O_{4}$, mp$142~143\circ$ was isolated from the fresh flowers of Chrysanthemun sinense Sabine in 0.16% yield. Its ir, nmr and mass spectral data suggested that it may have an aromatic methylester structure. Hydrolysis of this substane with 10% sodium hydroxide solution yielded terephthalic acid and methanol. This substance was confirmed as dimethyl terephthalate by comparison of ir and nmr spectra, and TLC and GC behaviors of an authentic sample which was prepared from terephthalic acid by methylation. This is the first report that dimethly terephthalate was isolated in the Composite plants.

• YAKHAK HOEJI
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• v.32 no.5
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• pp.308-312
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• 1988

A phenolic compound isolated from the ethylacetate extract of Duchesnea indica (Andr.) Focke (Rosaceae) showed antimicrobial activities against Staphylococcus aureus, Shigella dysentriae and Pseudomonas aeruginosa. This compound was identified as ellagic acid by spectral analysis.

• Korean Journal of Pharmacognosy
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• v.23 no.2
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• pp.115-116
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• 1992

From the bulbs of Erythronium japonicum Decaisne(Liliaceae), ${\beta}-sitosterol$ and its $3-O-{\beta}-D-glucoside$ together with fatty acids were isolated. All compounds were identified on the basis of spectral data. Campesterol and stigmasterol were also identified as minor components. Paimitic acid was identified as a major component and stearic, oleic, arachidic, behenic, tricosanoic and lignoceric acids were also characterized as minor ones.

• Journal of the Korean Magnetic Resonance Society
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• v.1 no.1
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• pp.71-77
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• 1997

Substritenone B, sesterterpenoids of an unprecedented akeletal class, has been isolated from the Antarctic sponge Suberites sp. Structure of this compound has been determined by combined spectral and chemical studies.

• Bulletin of the Korean Chemical Society
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• v.19 no.11
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• pp.1207-1210
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• 1998

The diamagnetic six-coordinate ruthenium polypyridyl complexes have been prepared and assigned. 1H NMR spectral studies were used to unravel the ligand field strength and the basicity on the chemical shift to the particular proton of ligand L in [(tpy)(L)RuⅡ(X)]+/2+ (L=bpy, bqi, dmbpy, phen; X=Cl, CN, N3, NCCD3, NO2, SCN) complexes.

• Bulletin of the Korean Mathematical Society
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• v.60 no.1
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• pp.257-279
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• 2023

Applying the Lyapunov-Schmidt reduction, we consider spectral stability of small amplitude stationary periodic solutions bifurcating from an equilibrium of the generalized Swift-Hohenberg equation. We follow the mathematical framework developed in [15, 16, 19, 23] to construct such periodic solutions and to determine regions in the parameter space for which they are stable by investigating the movement of the spectrum near zero as parameters vary.

• Archives of Pharmacal Research
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• v.16 no.4
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• pp.318-321
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• 1993

Cyanoaccetic acid hydrazide reacted with some 2-pyrazolin-5-one, isoxazol-5-one and 2-thiazolin-4-one and their ylidene derivatives to yield several new annelated pyran heterocycles. Structures wre established on the basis of elementary analyses and spectral data studies in addition to synthesis via other routes.

• Journal of The Korean Astronomical Society
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• v.31 no.1
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• pp.1-17
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• 1998

To understand the basic physics underlying large spatial fluctuations of intensity and Doppler shift, we have investigated the dynamical charctersitics of the transition region of the quiet sun by analyzing a raster scan of high resolution UV spectral band containing H Lyman lines and a S VI line. The spectra were taken from a quiet area of $100'\times100'$ located near the disk center by SUMER on board SOHO. The spectral band ranges from 906 A to 950 A with spatial and spectral resolution of 1v and $0.044 {\AA}$, respectively. The parameters of individual spectral lines were determined from a single Gaussian fit to each spectral line. Then, spatial correlation analyses have been made among the line parameters. Important findings emerged from the present analysis are as follows. (1) The integrated intensity maps of the observed area of H I 931 line $(1\times10^4 K)$ and S VI 933 line $(2\times10^5 K)$ look very smilar to each other with the same characterstic size of 5". An important difference, however, is that the intensity ratio of brighter network regions to darker cell regions is much larger in S VI 933 line than that in H I 931 line. (2) Dynamical features represented by Doppler shifts and line widths are smaller than those features seen in intensity maps. The features are found to be changing rapidly with time within a time scale shorter than the integration time, 110 seconds, while the intensity structure remains nearly unchanged during the same time interval. (3) The line intensity of S VI is quite strongly correlated with that of H I lines, but the Doppler shift correlation between the two lines is not as strong as the intensity correlation. The correlation length of the intensity structure is found to be about 5.7' (4100 km), which is at least 3 times larger than that of the velocity structure. These findings support the notion that the basic unit of the transition region of the quiet sun is a loop-like structure with a size of a few $10^3 km$, within which a number of unresolved smaller velocity structures are present.