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1.
Larval specimens ofHalicampus punctatus were collected off Ulsan and Uljin in December 2002 (three specimens) and off Ulsan in December 2003 (one specimen). These
specimens are characterized by the following morphological characteristics: rings, 14 + 35 = 49; subdorsal rings, 1 + 3 =
4; dorsal fin rays, 19 – 20; pectoral fin rays, 14 – 15; anal fin rays, 9; head length (HL), 5.8 – 6.7 in the standard length;
snout length, 1.9 in HL; snout depth, 3.7 – 5.2 in snout length. The number of caudal fin rays 9 is less than those of the
other species in the same genus 10. Wide stripe bands composed of small pigments are shown in the trunk and the tail. Melanophores
are not found in the dorsal fin, the pectoral fin, and the anal fin except the caudal fin. The supraoccipital crest is on
the head. The frontal ridge is on the dorsal side of front trunk. The blanched ridges on the opercular are fused with a main
ridge like a tree branch. A few branched ridges that are small and narrow on the trunk and the tail are fused with the main
ridges. We report these specimens as the first record in Korea and name them ‘Byeol-silgo-ki’ in Korean. 相似文献
2.
Moo Hee Kang Hyun-Chul Han Hyesu Yun Gee Soo Kong Kyong O. Kim Youn Soo Lee 《Marine Geophysical Researches》2007,28(3):257-269
A seamount chain with an approximately WNW trend is observed in the northeastern Ulleung Basin. It has been argued that these
seamounts, including two islands called Ulleung and Dok islands, were formed by a hotspot process or by ridge related volcanism.
Many geological and geophysical studies have been done for all the seamounts and islands in the chain except Anyongbok Seamount,
which is close to the proposed spreading ridge. We first report morphological characteristics, sediment distribution patterns,
and the crustal thickness of Anyongbok Seamount using multibeam bathymetry data, seismic reflection profiles, and 3D gravity
modeling. The morphology of Anyongbok Seamount shows a cone shaped feature and is characterized by the development of many
flank cones and flank rift zones. The estimated surface volume is about 60 km3, and implies that the seamount is smaller than the other seamounts in the chain. No sediments have been observed on the seamount
except the lower slope, which is covered by more than 1,000 m of strata. The crustal structure obtained from a 3D gravity
modeling (GFR = 3.11, SD 3.82 = mGal) suggests that the seamount was formed around the boundary of the Ulleung Plateau and
the Ulleung Basin, and the estimated crustal thickness is about 20 km, which is a little thicker than other nearby seamounts
distributed along the northeastern boundary of the Ulleung Basin. This significant crustal thickness also implies that Anyongbok
Seamount might not be related to ridge volcanism. 相似文献
3.
4.
Numerical analysis on post-grouted drilled shafts: A case study at the Brazo River Bridge,TX 总被引：1，自引：0，他引：1
This paper investigates the effects of post-grouting on the behavior of drilled shafts using a case study carried out at the Brazo River, Texas. Commercial finite element software, PLAXIS, was used to quantify the improvement of the tip resistance and side shear resistance of post-grouted drilled shafts (PGDS). The input material parameters of PLAXIS were initially estimated using CPT sounding results, and then the parameters were updated by calibrating the numerical results against full-scale STATNAMIC load test results. Based on the numerical analysis, the authors concluded that (1) the increase in total resistance of PGDS resulted from soil improvement at the shaft tip, (2) the apparent increase in side shear resistance resulted from side shear reversal that occurred during post-grouting, and (3) the apparent increase in the tip resistance of PGDS may be caused by stress relief of the grout. In addition, two approaches to estimate the resistance of PGDS were compared against numerical results. In this case study, the Axial Capacity Multiplier (ACM) approach over-predicted the total resistance whereas the Tip Capacity Multiplier (TCM) approach reasonably predicted the increase in total resistance. 相似文献
5.
In this study, the seismic fragility curves of two reinforced concrete (RC) columns that were lap-spliced at the bottom and retrofitted with steel wrapping jackets were generated. Their seismic performance was probabilistically assessed in comparison to that of lap-spliced or continuous reinforcement RC columns. This study used two types of steel wrapping jackets, a full jacket and a split jacket. Analytical models of the four types of columns were developed based on the experimental results of the columns using OpenSEES, which is effective in conducting nonlinear time history analyses. A suite of ten artificial ground motions, modified from recorded ground motions, was used to perform nonlinear time history analyses of the analytical models with scaling of the peak ground acceleration from 0.1 g to 1.0 g in increments of 0.1 g. The steel wrapping jackets did not increase the medians for yield (slight damage state) of the lap-spiced column and did not exceed the corresponding median of the continuous reinforcement column. However, the two steel jackets increased the medians for failure by 1.872 and 2.017 times, respectively, and exceeded the corresponding median of the continuous reinforcement column by 11.8% and 20.5%, respectively. 相似文献
6.
Evidence for significant clockwise rotations of the Korean Peninsula during Cretaceous 总被引：1，自引：0，他引：1
Youn Soo Lee Hyun-Chul Han Jae Ha Hwang Weon-Seo Kee Bok Chul Kim 《Gondwana Research》2011,20(4):904-918
In an effort to evaluate the Cretaceous magnetostratigraphy for the Korean Peninsula and to establish the tectonic coherence of its various elements, we collected paleomagnetic data from 121 samples from 20 sites within the Chilgok Formation (108.3–109.9 Ma) in the Gyeongsang Basin. Together with previously published data, we evaluate the results from a total of 163 sites in the basin.We combine our age model with results from recent stratigraphic, paleomagnetic and radiometric geochemical studies. In this study, we found that two distinct declination shifts decrease with younging direction, indicating two clockwise rotational events of the Korean Peninsula with respect to the Eurasia continent. The earlier event took place during 130–100 Ma (Phase I, newly termed “Goguryeo Disturbance”) and a later one during 80–50 Ma (Phase III, belonging to “Bulguksa Orogeny”). The mean rotation rate in the interval from 115.2 to 103.8 Ma (Phase I) is about 0.74°/Ma, while the rate from 90.9 to 79.8 Ma (Phase II) is 0.19°/Ma. Based on paleolatitude change during Phase I, we infer that the Korean Peninsula (eastern part of the Sino-Korea Block) migrated southward about 300 km after the complete amalgamation of the Sino-Korea Block into the Eurasian continent resulting in N–S compression within the Korean peninsula and Manchuria. Large-scale strike-slip faults (e.g., Tan-Lu Fault, Okcheon Boundary Fault) were probably rejuvenated in the Sino-Korea Block during Phase I. 相似文献
7.
8.
Distribution pattern of zooplankton in the han river estuary with respect to tidal cycle 总被引：1，自引：0，他引：1
The monthly distribution of zooplankton communities in Han River estuary was investigated at two stations from July 1998 to
June 1999. Monthly mean abundance of total zooplankton varied remarkably, with the range from 20 indiv.·m-3 to 19,600 indiv.·m-3. During the study period, dominant species of zooplankton community were dinoflagellateNoctiluca scintillans, copepodsParacalanus indicus, Paracaanus crassirostris, Acartia hongi, Acartia ohtsukai, and meroplanton cirriped larvae. According to tidal states, relative high abundance occurred at high tide without regard
to season. The temporal distribution of abundance implied that the reduced salinity probably limited the zooplankton populations
and the fluctuations of salinity were an important factor in the variation of abundance. However, the results of salinity
tolerance test shows that the variations in salinity do not directly influence the decrease of abundance. This study shows
that the relatively high abundance of zooplankton near high tide seems to be related with the expansion of abundant zooplankton
inhabiting Incheon coastal waters through tidal currents. 相似文献
9.
Jong-Woo Park Seung Won Nam Hyung Seop Kim Seok-Hyun Youn Wonho Yih 《Ocean Science Journal》2014,49(1):11-18
Photobiological H2 from marine cyanobacterial strains is widely accepted to be an ideal clean and renewable energy source. Using the two Korean N2-fixing unicellular cyanobacterial strains (Cyanothece sp. KNU CB MAL-031 and Cyanothece sp. KNU CB MAL-058) and the Synechococcus sp. Miami strain BG043511 we performed flask-scale experiments to measure the effect of CO and HCN addition on photobiological H2 production. For the test, 1, 5, 10 and 30% v/v of CO in the N2 atmosphere was applied. Enhancement of H2 production was remarkable at 1–5% concentration range of CO addition. At CO concentrations over 5% no further cost-effective enhancement of H2 production was detectable, which suggests to us that 1–5% CO addition should be adopted for practical photobiological H2 production by the cyanobacterial strains. Maximum enhancement of the photobiological H2 production by CO additions was 2–6 times over the control flasks without CO. When 3 ppm of HCN was injected into the cell suspension of BG043511, the enhancement of hydrogen production was 50–60% of that under 5% CO. Present result implies the possible recycling of waste CO and HCN for the enhancement of the photobiological H2 production using marine cyanobacterial strains. 相似文献
10.
Byung-Kwon Moon Daeok Youn Rokjin J. Park Sang-Wook Yeh Won-Mo Kim Young-Ho Kim Jaein I. Jeong Jung-Hun Woo Eul Gyu Im Chang-Keun Song 《Asia-Pacific Journal of Atmospheric Sciences》2011,47(4):345-351
We examine the meteorological responses due to the probable eruption of Mt. Baekdu using an off-line Climate-Chemistry model that is composed of the National Center for Atmospheric Research (NCAR) Climate Atmosphere Model version 3 (CAM3) and a global chemistry transport model (GEOS-Chem). Using the aerosol dataset from the GEOS-Chem driven by GEOS-5 meteorology, experiment and control simulations of the climate model are performed and their meteorological differences between the two simulations are analyzed. The magnitudes of volcanic eruption and column injection height were presumably set to 1/200 of the Mt. Pinatubo eruption and 9 km, respectively. Significant temperature drop in the lower troposphere (850 hPa), which is mainly due to a direct effect of prescribed volcanic aerosols from Mt. Baekdu, has been simulated up to about ?4 K. The upper atmosphere (150 hPa) right above the volcano, however, shows significant warming due to the absorption of the infrared radiation by volcanic aerosols. As a result of the volcanic eruption in the climate model, wave-like patterns are shown in both the geopotential height and horizontal wind. The changes in the lower atmospheric temperature are well associated with the modification of the atmospheric circulation through the hydrostatic balance. In spite of limitations in our current simulations due to several underlying assumptions, our results could give a clue to understanding the meteorological impacts from Mt. Baekdu eruptions that are currently attracting considerable public attention. 相似文献