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31.
Sang-kon Kim Maeng-eon Park Seung-gyun Baek Kyu-youl Sung Sun-ok Kim Hee-yul Park 《世界地质(英文版)》2004,7(2)
Chemical composition, Raman microspectrometry, and Fourier transform infrared (FT-IR) and SEM-CL (Cathodluminescence) analyses are carried out for Tanzania and Madagascar garnets for locality identification. Inclusion study was sustained after electron probe microanalysis (EPMA). Needle-like illmenites, apatites and zircons were the most common solid inclusions in Tanzania garnets. Madagascar garnets revealed rutile needles and apatites were also observed, but differences in size, shape and distribution patterns were noticed compared to Tanzania garnets. Tanzania garnets exhibited all types of observable fluid inclusions such as "fingerprint" pattern, called Type Ⅰ-A, liquid-only (L) single phase fluid inclusion, called Type Ⅰ-B and Type Ⅱ-A (L + S), Type Ⅱ-B (L + V) and Type Ⅲ-A (L + Sylvite +S), Type Ⅲ-B (L+S+V), while no more than two phase fluid inclusions found in both Madagascar and Korea garnets even if all examined garnets from three localities retained "fingerprint" features, so called, partially healed fractures, in common. Chemical composition, Raman microspectrometry and Fourier transform infrared (FT-IR) analysis taken turned out to be useful methods for the purpose of this study. Using consequences of SEM-CL and inclusion study, accordingly,the locality identification of gem-quality garnets is capable of being available in further application for other kinds of gemstones. 相似文献
32.
伴随韩国雨季开始和结束早晚的关联场分析 总被引：4，自引：0，他引：4
分析了与韩国雨季开始和结束的年际变化相关联的一些要素场发生的变化。分别对雨季开始和结束早晚的个例进行了合成分析。６月月平均资料用来分析与雨季开始早晚相关联的要素场变化，而在分析与雨季结束早晚相关联的要素场变化时则利用７月月平均资料。结果表明，对应雨季开始（或结束）早晚，大气环流和表面温度等要素不仅在东亚地区、而且在远离东亚的地方具有显著的差异。在东亚地区的显著差异主要是高空急流和西太平佯副热带高压。远离东亚的显著差异主要是印度季风和ＥＮＳＯ现象。印度季风与韩国雨季开始和结束均有关联，但ＥＮＳＯ现象只与雨季开始显著相关、而与结束并没有显著的关联。 相似文献
33.
Population Development of the DinoflagellatesCeratium furca andCeratium fusus during Spring and Early Summer in Iwa Harbor, Sagami Bay, Japan 总被引：2，自引：0，他引：2
To examine the population development of the dinoflagellates, Ceratium furca and Ceratium fusus, daily field monitoring was
conducted between April and July 2003 in the temperate coastal water of Sagami Bay, Japan. During the study period, the concentrations
of C. furca were always lower than those of C. fusus. A sharp increase in the densities of both species was recorded on 5
May showing the maximum cell concentrations (C. furca = 14,800 cells L-1, C. fusus = 49,600 cells L-1). In the 7 days prior to the May bloom of the Ceratium species (29 April to 1 May), the highest density of the heterotrophic
dinoflagellate Noctiluca scintillans was observed. Additionally, a second bloom of C. fusus occurred on 22 July. Here, two
causes of the significant increases in the Ceratium populations during the two blooming periods (first time; 1 to 8 May, second
time; 15 to 22 July) are presented. First, an increase in the nutrients of the surface layer regenerated by the breakdown
of blooms by N.scintillans could be considered as a major cause of the population increase of the two Ceratium species. Second,
a decrease in salinity (to 27 psu) was correlated with the later bloom ofC. fusus. These results suggest that the population development of the two Ceratium species requires nutrients regenerated after the
reduction of the diatom population byN. scintillans and, forC. fusus, continuous low salinity conditions, compared to other environmental factors during the rainy season. Key words: Ceratium
furca; Ceratium fusus; Noctiluca scintillans; Bloom process; Environmental factor 相似文献
34.
Lee Minji Kim Jin Ho Kim Yun-Bae Park Chan Hong Shin Kyoungsoon Baek Seung Ho 《海洋学报(英文版)》2020,39(2):107-122
The East Sea(Sea of Japan)is a marginal,semi-closed sea in the northwestern Pacific.The Ulleung Basin area,which is located near the subpolar front of the East Sea,is known to have high primary production and good fisheries in spring season.After episodic wind-driven events during the spring of 2017,horizontal and vertical profiles of physical chemical biological factors were investigated at 29 stations located in the Ulleung Basin area.In addition,growth responses of phytoplankton communities to nutrient additions were evaluated by bioassay experiments to understand the fluctuation of phytoplankton biomass.Because of strong northwestern wind,phytoplankton biomass was scattered and upwelling phenomenon might be suppressed in this season.The phytoplankton abundances in the coastal stations were significantly higher than offshore and island stations.In contrast,the nutrient and chlorophyll a(Chl a)concentrations and the phytoplankton biomass were quite low in all locations.Bacillariophyceae was dominated group(>75.1%for coastal,40.0%for offshore and 43.6%for island stations).In the algal bioassays,the phytoplankton production was stimulated by N availability.The in vivo Chl a values in the+N and+NP treatments were significantly higher than the values in the control and the+P treatments.Based on the field survey,the higher nutrients in coastal waters affected the growth of diatom assemblages,however,little prosperity of phytoplankton was observed in the offshore waters despite the injection of sufficient nutrients in bioassay experiments.The growth of phytoplankton depended on the initial cell density.All of results indicated that a dominant northwestern wind led to a limited nutrients condition at euphotic layers,and the low level of biomass supply from the coasts resulted in low primary production.Both supplying nutrients and introducing phytoplankton through the currents are critical to maintain the high productivity in the Ulleung Basin area of the East Sea. 相似文献
35.
Electrokinetic (EK) process was performed to restore sulfate‐originated saline soil and to evaluate the effect of treatment duration. Sulfate and potassium were the major ionic salts in the saline soil used in this study. A constant voltage gradient of 1 V/cm was applied for 8, 12, and 16 days. After EK treatment, anions and cations were transported toward anode and cathode, respectively, by electromigration. Chloride was completely removed, and 85.6% of nitrate was removed after 8 days of treatment. The increase of treatment period from 8 to 12 days had a negligible effect on the enhancement in the rate of sulfate removal; however, over 70% was removed after16 days. At the end of experiment, the electrical conductivity (EC) of the soil, an indicator of soil salinity, decreased to 1.93 dS/m from an initial value of 5.3 dS/m, and the distribution of sulfate was similar to that of EC. The operation time of 16 days was sufficient to restore the sulfate‐originated saline soil using the EK process. 相似文献
36.
Eun-Hyuk Baek Joo-Hong Kim Jong-Seong Kug Gyu-Ho Lim 《Asia-Pacific Journal of Atmospheric Sciences》2013,49(3):333-346
This study identifies favorable synoptic backgrounds for indirect precipitation events over the Korean Peninsula that occur well in advance of tropical cyclone (TC) landfall. Two TCs, i.e., Rammasun (2002) and Maemi (2003) that made landfall and produced heavy rainfall over the Peninsula are compared. Although both had a remarkably similar accumulated rainfall pattern over the peninsula, the temporal evolutions of hourly rainfall were different. Only Maemi had an indirect precipitation event in conjunction with a midlatitude trough to its north. The confluent flows at middle-to-upper levels were strengthened due to the increased pressure gradient between the midlatitude trough and the subtropical high, and the warm advection by the confluent flows also became stronger near the confluent zone. By contrast, Rammasun encountered the subtropical ridge while moving northward, which results in slow recurvature and reduction of the thermal gradient over the peninsula. The highly baroclinic synoptic backgrounds in the Maemi case lead to the midlevel frontogenesis. Budget analyses using the three-dimensional frontogenesis equation revealed that the horizontal deformation forcing had a primary role in generating the front. The front was associated with a thermally direct circulation that contributed to strong ascent and indirect precipitation over the peninsula well in advance of the landfall of Maemi. Moreover, the indirect precipitation could intensify due to the abundant low-level moisture supply to the frontal zone by the southerly wind on the east side of the TC. 相似文献
37.
Youngsaeng Lee Sanghoo Yoon Md. Sharwar Murshed Maeng-Ki Kim ChunHo Cho Hee-Jeong Baek Jeong-Soo Park 《大气科学进展》2013,30(6):1608-1620
This paper examines the annual highest daily maximum temperature （DMT） in Korea by using data from 56 weather stations and employing spatial extreme modeling. Our approach is based on max-stable processes （MSP） with Schlather＇s characterization. We divide the country into four regions for a better model fit and identify the best model for each region. We show that regional MSP modeling is more suitable than MSP modeling for the entire region and the pointwise generalized extreme value distribution approach. The advantage of spatial extreme modeling is that more precise and robust return levels and some indices of the highest temperatures can be obtained for observation stations and for locations with no observed data, and so help to determine the effects and assessment of vulnerability as well as to downscale extreme events. 相似文献
38.
Hydrocarbon compounds in aquifers are generally known to show a retardation effect due to sorption onto the surfaces of solid particles. In this study, we investigated the effect of sorption on the transport of benzene in sandy aquifer materials by conducting batch and column tests for both sandy aquifer materials and sandy materials to which had been added 0·5% powdered activated carbon. The batch test was conducted by equilibrating dry materials with benzene solutions of various initial concentrations, and by analysing the concentrations of benzene in the initial and equilibrated solutions using high‐performance liquid chromatography (HPLC). The column test was performed to monitor the concentrations of effluent versus time, known as a breakthrough curve (BTC). We injected KCl and benzene solutions as tracers into the inlet boundary as two different types of square pulse and step, and monitored the effluent concentrations at the exit boundary under a steady‐state condition using an electrical conductivity meter and HPLC. Simulation of benzene transport was performed using the convective–dispersive equation model with the distribution coefficients obtained from the batch test and the transport parameters of the conservative solute KCl from the column test. The observed BTCs of KCl and benzene for pulse injection showed that the arrival times of the peaks of both tracers coincided well, but the relative peak concentration of benzene was much lower than that of KCl. Comparison of the simulated and observed BTCs showed a great discrepancy for all cases of injection mode and material texture, indicating the absence of retardation effect. These results reveal that the predominant process affecting the benzene transport in the sandy aquifer materials is an irreversible sorption rather than retardation. This tentative conclusion was verified by simulation of benzene transport using an irreversible sorption parameter that led to a good agreement between the simulated and observed BTCs. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
39.
Eun-Hyuk Baek Gyu-Ho Lim Joo-Hong Kim Jong-Seong Kug 《Theoretical and Applied Climatology》2014,118(1-2):9-24
This study examines antecedent mid-tropospheric frontogenesis (AMF) resulting from the interaction between Typhoon Rusa (2002) and a midlatitude trough over the Korean Peninsula. In this event, the AMF contributed to the first peak in the time series of rainfall in Gangneung (37.75°N, 128.90°E), occurring about 12 h before the time of the extratropical transition (ET) process of the tropical cyclone (TC). Using observations and high-resolution model outputs, we showed that the AMF contributed to the antecedent rainfall in Gangneung during the first rainfall period when Gangneung was located outside of Rusa's sphere of direct influence. A Weather Research Forecasting (WRF) model experiment was conducted to diagnose the frontogenetical features and associated precipitation processes in detail. The experiment revealed that the AMF was mainly forced by the horizontal deformation forcing (HDF). The direction of the HDF was oriented from southwest to northeast in the middle part of the peninsula. The HDF increased positively due to the confluence of the southeasterlies from the TC and the northwesterlies emanating from the midlatitude trough. The experiment also suggested that the mid-tropospheric moisture originated from the subtropical ocean and deposited into the frontal region by the southerlies on the eastern periphery of the TC, which enhanced the convergence of moisture flux in the frontal region during the first rainfall period. The thermally direct circulation associated with the AMF lead to the mid-tropospheric saturation, which enhanced the precipitation of the first rainfall event together with the orographically forced convection at the low level above Gangneung. 相似文献
40.
Jae-Hyun Lim Seunghyun Son Jung-Woo Park Jung Hyun Kwak Chang-Keun Kang Young Baek Son Jung-No Kwon Sang Heon Lee 《Ocean Science Journal》2012,47(3):377-385
The high primary production enhanced by anticyclonic eddies and hourly variation pattern in the productivity during the spring season in the East Sea were first investigated using the first Korean Geostationary Ocean Color Imager (GOCI). Even though the stratification for a seasonal spring bloom is not well developed in the water column in early April in the East Sea, a physical upward water flux movement at the periphery of the anticyclonic eddies could remain the phytoplankton in euphotic zone to sustain high chlorophyll-a concentration conditions in the Ulleung Basin. At this time, nutrients were no major controlling factor for phytoplankton growth since concentrations of major nutrients (nitrate, silicate, and phosphate) were relatively high in the observed eddy sites based on the observation data from the Korean Oceanographic Data Center (KODC). The estimated mixed layer depth (MLD) significantly shallower at the periphery supports for this mechanism. The hourly primary productivity estimation based on a Carbon-based Productivity Model (CbPM) provides a bimodal pattern along the time especially in L1 with an approximately one order magnitude difference between the lowest and highest values of productivities on 5 April, 2011. Potential possibilities for this large discrepancy in the hourly productivity and some thoughts on a short time in situ incubation method were discussed. 相似文献