Morphological and genetic comparison of two strains of a Prorocentrum species isolated from Zhejiang coastal water of China and Masan Bay of Korea     

½����  ����ϼ  �ƺ���  ��ƽ  ���η� 《中国海洋湖沼学报》2011,29(4):832-839

In this paper, we examined the detailed morphology of two strains of Prorocentrum isolated from the coastal waters of Zhejiang (Wenling area), China, and Masan Bay of Korea. A taxonomic comparison was made among strains on the basis of morphological and molecular data. The cellular dimensions of the Chinese Wenling strain (LAMB090508) and Korean strain (PDKS0206) were similar and the cells of both strains were of asymmetric and elongated shape. The posterior end of most cells was rounded. Megacytic zones of aged cells were broader with dense tiny knobs. The roundish nucleus was located in the posterior part of the cell. A few irregular shaped chloroplasts were distributed within the cell. The nucleotide similarity of the two strains, determined from the 5.8S rDNA-ITS sequences, was 99.83%. The comparative results of morphology and molecular analysis suggest that both strains isolated from China and Korea were the identical species, Prorocentrum donghaiense Lu.  相似文献   

Comparison of radiocarbon and OSL dating methods for a Late Quaternary sediment core from Lake Ulaan,Mongolia     

Min Kyung Lee  Yong Il Lee  Hyoun Soo Lim  Jae Il Lee  Jeong Heon Choi  Ho Il Yoon 《Journal of Paleolimnology》2011,45(2):127-135

Both radiocarbon and optically stimulated luminescence (OSL) dating methods were applied to test their suitability for establishing a chronology of arid-zone lacustrine sediments using a 5.88-m-long core drilled from Lake Ulaan, southern Mongolia. Although the radiocarbon and OSL ages agree in some samples, the radiocarbon ages are older than the corresponding OSL ages at the 550-cm depth horizon (late Pleistocene) and in the 100–300-cm interval (early to late Holocene). In the early to late Holocene, radiocarbon ages are consistently older than OSL ages by 4,100–5,800 years, and in the late Pleistocene by 2,700–3,000 years. Grain-size analysis of early to late Holocene sediments and one late Pleistocene sediment sample (550-cm depth) indicates that eolian processes were the dominant sediment-transport mechanism. Also, two late Pleistocene sediments samples (from 400- to 500-cm depths) are interpreted to have been deposited by both eolian and glaciofluvial processes. Accordingly, the radiocarbon ages that were older than the corresponding OSL ages during the Holocene seem to have been a consequence of the influx of ¹⁴C-deficient carbon delivered from adjacent soils and Paleozoic carbonate rocks by the westerly winds, a process that is also active today. In addition to the input of old reworked carbon by eolian processes, the late Pleistocene sediments were also influenced by old carbon delivered by deglacial meltwater. The results of this study suggest that when eolian sediment transport is suspected, especially in lakes of arid environments, the OSL dating method is superior to the radiocarbon dating method, as it eliminates a common ‘old-carbon’ error problem.  相似文献   

Mineralogical and geochemical characterization of precipitates on stream receiving acid mine water, Korea     

Eum Sik Woo  Jeong Jin Kim  Young Hun Kim  Gyo Cheol Jeong  Yun Deuk Jang  Warren A. Dick 《Environmental Earth Sciences》2013,69(7):2199-2209

Seasonal variations of water chemistry occurred in acid mine drainage receiving mine and leachate water. Sulfate and metal concentrations were low in winter but high in spring and summer. Mine waters were highly acidic (up to pH 3.4) in nature with high concentrations of manganese, copper and zinc but high electrical conductivity and sulfate in leachate. The blue and brownish yellow precipitates were formed under different chemical environments of acid mine drainage. Brownish yellow (Munsell color 7.5YR 8/12), blue (Munsell color 2.5B 9/7) and light blue (Munsell color 2.5B 9/3) precipitates deposited on the stream bottom receiving acid mine water. The brownish yellow precipitates formed in the acid mine water, whereas the blue and light blue precipitates formed in the leachate water. The brownish yellow precipitates consisted mainly of ferrihydrite, whereas the blue and light blue precipitates consisted of glaucocerinite and/or woodwardite.  相似文献   

Comparison of the Ordovician-Carboniferous Boundary Between Korea and NE China: Implications for Correlation and Tectonic Evolution   总被引：2，自引：0，他引：2  

Jeong Hwan Kim  Yong Il Lee  Maosong Li  Zhiquiang Bai 《Gondwana Research》2001,4(1)

There is a great hiatus between Ordovician and Carboniferous strata in the Northeast China and Korean Peninsula. In order to understand geology and tectonic evolution, and to find out the similarities and differences in both regions, two sections in the Western Hill near Beijing in NE China and several sections in the Korean Peninsula were selected to examine their geologic boundaries between Lower and Upper Paleozoic strata to compare their characteristic features. At four sites in the two sections in the Western Hill near Beijing were examined their contact relations. The Hui Yu section is the same horizon where one site is top of a quarry hill and the other of down hill. Mid-Carboniferous Qingshuijian Formation rests on the Ordovician Majiagou Formation. Limestone beds are more commonly intercalated with shale and sandstone at site 2 of the Hui Yu section, while at site 1, conglomerate beds are dominant. Site 1 of the Se Shu Fen section shows eroded and concealed karst topography and conglomerate beds are intercalated within shale beds. Silurian and Devonian strata are absent in these areas. In the Korean Peninsula, most O-C contacts occur between Ordovician limestone formation and Carboniferous strata, although Silurian strata occur beneath the Carboniferous strata in the Jeongseon area and Pyeongnam Basin. Most contact relations are parallel unconformity and angular unconformity is rarely seen. The O-C relations in both regions are similar to each other, and these indicate that the Korean Peninsula was located near or belonged to the Sino-Korean paraplatform during Paleozoic time.  相似文献   

Development of an Operational Hybrid Data Assimilation System at KIAPS     

In-Hyuk Kwon  Hyo-Jong Song  Ji-Hyun Ha  Hyoung-Wook Chun  Jeon-Ho Kang  Sihye Lee  Sujeong Lim  Youngsoon Jo  Hyun-Jun Han  Hanbyeol Jeong  Hui-Nae Kwon  Seoleun Shin  Tae-Hun Kim 《Asia-Pacific Journal of Atmospheric Sciences》2018,54(1):319-335

This study introduces the operational data assimilation (DA) system at the Korea Institute of Atmospheric Prediction Systems (KIAPS) to the numerical weather prediction community. Its development history and performance are addressed with experimental illustrations and the authors’ previously published studies. Milestones in skill improvements include the initial operational implementation of three-dimensional variational data assimilation (3DVar), the ingestion of additional satellite observations, and changing the DA scheme to a hybrid four-dimensional ensemble-variational DA using forecasts from an ensemble based on the local ensemble transform Kalman filter (LETKF). In the hybrid system, determining the relative contribution of the ensemble-based covariance to the resultant analysis is crucial, particularly for moisture variables including a variety of horizontal scale spectra. Modifications to the humidity control variable, partial rather than full recentering of the ensemble for humidity further improves moisture analysis, and the inclusion of more radiance observations with higher-level peaking channels have significant impacts on stratosphere temperature and wind performance. Recent update of the operational hybrid DA system relative to the previous 3DVar system is described for detailed improvements with interpretation.  相似文献   

Wave Climatology in Coastal Maine for Aquaculture and Other Applications     

Vijay G. Panchang  Chankwon Jeong  Dongcheng Li 《Estuaries and Coasts》2008,31(2):289-299

Wind waves represent a significant hydrodynamic factor affecting many oceanographic studies such as sediment transport, design of structures, etc. In coastal Maine, wave information is needed, among other applications, for aquaculture-related activities. As few data sources exist, a question that confronts scientists pertains to the magnitudes of typical and extreme wave conditions at various times. To address this, numerical modeling was performed for a period of six and a half years (7/99–12/05) on a continuous basis by coupling National Oceanic and Atmospheric Administration’s outer ocean predictions to two coastal, high-resolution, regional domain grids encompassing the Penobscot Bay and Machias Bay regions where aquaculture activity is prevalent and expanding. As the modeling involves uncertainties because of bathymetric and wind field representations, their effect on the results was explored. It was found that although the uncertainties could create inaccuracies in real-time forecasts, their effect on the development of climatogies was minimal. Average modeled significant wave heights are found to vary between 0.6 and 1.5 m in the sub-domains. The maximum conditions are of the order of 6.5 m in the outer parts of the sub-domains and occurred in September and December. Estimated wave-induced bottom velocities were found in many areas to be in excess of the published estimates of resuspension thresholds for net-pen wastes. Estimates of “extreme” wave conditions, corresponding to a recurrence interval of 30 years (representing the nominal design life of the cage), were found to vary between 2 and 7 m in the modeled areas. Detailed contour maps have been developed for site-specific characterization of the wave climate.  相似文献   

Characterization of synthetic nanocrystalline mackinawite: crystal structure, particle size, and specific surface area     

Jeong HY  Lee JH  Hayes KF 《Geochimica et cosmochimica acta》2008,72(2):493-505

Iron sulfide was synthesized by reacting aqueous solutions of sodium sulfide and ferrous chloride for 3 days. By X-ray powder diffraction (XRPD), the resultant phase was determined to be primarily nanocrystalline mackinawite (space group: P4/ nmm) with unit cell parameters a = b = 3.67 Å and c = 5.20 Å. Iron K-edge XAS analysis also indicated the dominance of mackinawite. Lattice expansion of synthetic mackinawite was observed along the c-axis relative to well-crystalline mackinawite. Compared with relatively short-aged phase, the mackinawite prepared here was composed of larger crystallites with less elongated lattice spacings. The direct observation of lattice fringes by HR-TEM verified the applicability of Bragg diffraction in determining the lattice parameters of nanocrystalline mackinawite from XRPD patterns. Estimated particle size and external specific surface area (SSA_ext) of nanocrystalline mackinawite varied significantly with the methods used. The use of Scherrer equation for measuring crystallite size based on XRPD patterns is limited by uncertainty of the Scherrer constant (K) due to the presence of polydisperse particles. The presence of polycrystalline particles may also lead to inaccurate particle size estimation by Scherrer equation, given that crystallite and particle sizes are not equivalent. The TEM observation yielded the smallest SSA_ext of 103 m²/g. This measurement was not representative of dispersed particles due to particle aggregation from drying during sample preparation. In contrast, EGME method and PCS measurement yielded higher SSA_ext (276-345 m²/g by EGME and 424 ± 130 m²/g by PCS). These were in reasonable agreement with those previously measured by the methods insensitive to particle aggregation.  相似文献   

Prediction of nonstationary climatic series     

A. R. Rao  C. H. Hsieh  G. D. Jeong 《Theoretical and Applied Climatology》1992,46(2-3):75-87

Summary Most of the stochastic prediction methods are developed for stationary time series. However, many climatic series show clear evidence of non-stationarity. In such cases, methods based on the stationarity assumptions would be inappropriate. Alternative methods such as those based on stochastic approximation are preferable in these cases because they are based on adaptive learning principles. These methods have not been applied and their suitability not tested with nonstationary climatic time series.In the stochastic approximation method, the deterministic component of a nonstationary time series is estimated by first predicting the two steps ahead value of a time series. The two steps-ahead forecast may involve a term characterizing the trend in the time series. The two steps-ahead predictor is corrected to obtain the one step ahead prediction by using a gain sequence.The dynamic stochastic approximation method is used herein to predict non-stationary climatic time series. Daily minimum temperature series at West Lafayette, Indiana, U.S.A. and seasonal temperature and precipitation series at Evansville, Indiana, U.S.A. are used in the study. For data trends, an improved dynamic stochastic approximation method, called the modified dynamic stochastic approximation method gives more accurate predictions. If the method is used for seasonal data, then it can be used to track the time varying mean value.With 6 Figures  相似文献   

Evaluating the impacts of fine-scale capillary heterogeneity and wettability on the behavior of buoyancy-driven CO<Subscript>2</Subscript> migration and trapping mechanisms     

Sung Soo Park  Tae Hong Kim  Moon Sik Jeong  Kun Sang Lee 《Environmental Earth Sciences》2016,75(7):550

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Trilobite Biostratigraphy of the lower Paleozoic (Cambrian–Ordovician) Joseon Supergroup, Taebaeksan Basin, Korea   总被引：1，自引：0，他引：1  

CHOI Duck K.  LEE Jeong Gu  LEE Seung-Bae  PARK  Tae-Yoon S.  HONG Paul S. 《《地质学报》英文版》2016,90(6):1976-1999

In Korea,trilobites are among the most intensively studied fossil groups in the past century and provide invaluable information about lower Paleozoic stratigraphy,paleogeography,and tectonics of the Korean Peninsula. Trilobites occur in the lower Paleozoic Joseon Supergroup of the Taebaeksan Basin which was part of the Sino-Korean Craton in the Paleozoic. The Joseon Supergroup is divided into the Taebaek,Yeongwol,and Mungyeong groups. The Taebaek and Yeongwol groups are richly fossiliferous,while the Mungyeong Group is poorly fossiliferous. Contrasting trilobite faunal contents of the Taebaek and Yeongwol groups resulted in two separate biostratigraphic schemes for the Cambrian–Ordovician of the Taebaeksan Basin. A total of 22 biozones or fossiliferous horizons were recognized in the Taebaek Group; 19 zones were established in the Yeongwol Group; and four biozones were known from the Mungyeong Group. These trilobite biozones of the Taebaeksan Basin indicate the Joseon Supergroup ranges in age from the Cambrian Series 2 to Middle Ordovician and can be correlated well with the formations of North China,South China,and Australia.  相似文献