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71.
The aim of the present study is to optimize the slow release biostimulant ball (BSB) for bioremediation of contaminated coastal sediment using response surface methodology (RSM). Metals contamination and stabilization of metals in coastal sediments using BSB were investigated. The effects of BSB size (1–5 cm), distance (1–10 cm), and time (1–4 months) on the stabilization of metals including Fe, Cd, Cu, and Pb were determined. The maximum stabilization percentages of Fe, Cd, Cu, and Pb, of 64.5%, 54.9%, 63.8%, and 47.6%, respectively, were observed at a 3 cm ball size, 5.5 cm distance, and a period of 4 months; these values are the optimum conditions for effective treatment of contaminated coastal sediment. The determination coefficient of the R2 value suggests that > 91.55%, 89.97%, 96.10%, and 86.40% of the variance is attributable to the variables of Fe, Cd, Cu, and Pb, respectively. 相似文献
72.
Yoon Eun-A Lee Kyounghoon Chae Jinho Yoon Wonduk Han Changhoon Lee Hyeeun Kim Pyungkwan Oh Wooseok 《Ocean Science Journal》2019,54(3):457-465
Ocean Science Journal - Using nets and acoustic frequencies of 38 and 120 kHz, we estimated the density distribution of the moon jellyfish, Aurelia coerulea, in the Yeongsan Estuary, where a large... 相似文献
73.
Nemopilema nomurai, an endemic and blooming jellyfish species in the waters of Korea, China and Japan, were monitored from June to October, 2017, in the Bohai and northwestern Yellow Seas, using the ship sighting method, as a preliminary study to investigate the spatiotemporal distribution of medusae. Monitoring revealed that the mass appearance of young medusae was observed in Liaodong Bay in summer. In late summer they disappeared and a high density zone shifted to the mid- and northern Bohai Strait. In early fall, healthy adults with relatively high density were observed in the area around the border of the South and North Yellow Seas. These results suggest that medusae of N. nomurai originated from the Bohai Sea and were advected into the Yellow Sea through the Bohai Strait. 相似文献
74.
On 27 September 1998, Big Bear Solar Observatory (BBSO) and Transition Region and Coronal Explorer (TRACE) coordinated observations from 16:00 to 19:00 UT to study properties of microflares in AR NOAA No. 8340. Fortuitously, a C5.2 flare occurred at 16:30 UT in this active region. H and magnetograph movies were obtained at BBSO; Civ 1550 Å, Feix 171 Å, and Fexii 195 Å movies were obtained by TRACE; both with a cadence about 1 min. In this paper, we concentrate on the study of magnetic properties of 70 Civ microflares, as well as their relationship to the C5.2 flare. We obtained the following results: (1) We found two kinds of microflares: microflares of transient brightenings with a time scale of 1 to 5 min (impulsive events) and microflares lasting half an hour or longer (persistent events). Ninety percent of the microflares are impulsive events. Most of the event in this category are associated with well defined magnetic neutral lines, but some are found in non-neutral line areas. All of seven persistent events are found at parasitic magnetic configurations with inclusions of small magnetic flux within dominant magnetic flux of opposite polarity. (2) More than a third of the impulsive microflares occurred near the C5.2 flare site indicating that a local instability is responsible for both the C5.2 flare and microflares. This indirectly supports the avalanche theory of flare energy release, which implies that a big flare may be spatially associated with many small flares. 相似文献
75.
In this study, a numerical modeling system based on the dispersion–correction finite difference scheme equipped with a grid-nesting
scheme is constructed. The model is applied to simulate the propagation of three historical tsunami events that attacked the
east coast of Korea. The calculated free-surface displacements for the cases of the 1983 Akita and the 1993 Okushiri tsunamis
are compared with the observations at four tidal stations along the east coast of Korea. The comparison shows that the results
agree well with the observations. The analyses of the simulated results show that underwater topography, such as submerged
rises and ridges, plays an important role in the propagation of tsunamis in this region. 相似文献
76.
Large‐scale real‐time hybrid simulation of a three‐story steel frame building with magneto‐rheological dampers 
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下载免费PDF全文 A series of large‐scale real‐time hybrid simulations (RTHSs) are conducted on a 0.6‐scale 3‐story steel frame building with magneto‐rheological (MR) dampers. The lateral force resisting system of the prototype building for the study consists of moment resisting frames and damped brace frames (DBFs). The experimental substructure for the RTHS is the DBF with the MR dampers, whereas the remaining structural components of the building including the moment resisting frame and gravity frames are modeled via a nonlinear analytical substructure. Performing RTHS with an experimental substructure that consists of the complete DBF enables the effects of member and connection component deformations on system and damper performance to be accurately accounted for. Data from these tests enable numerical simulation models to be calibrated, provide an understanding and validation of the in‐situ performance of MR dampers, and a means of experimentally validating performance‐based seismic design procedures for real structures. The details of the RTHS procedure are given, including the test setup, the integration algorithm, and actuator control. The results from a series of RTHS are presented that includes actuator control, damper behavior, and the structural response for different MR control laws. The use of the MR dampers is experimentally demonstrated to reduce the response of the structure to strong ground motions. Comparisons of the RTHS results are made with numerical simulations. Based on the results of the study, it is concluded that RTHS can be conducted on realistic structural systems with dampers to enable advancements in resilient earthquake resistant design to be achieved. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
77.
The TRACE/BBSO joint campaign on 27 September 1998 observed an eruptive flare event which lasted for half an hour. The observation covered several ultraviolet (UV) and extreme-ultraviolet (EUV) lines and H center and off-band emissions with very high spatial resolution. We find the EUV emissions in different stages of the flare display different characteristics. (1) During the `pre-flare' phase, when the SXR output was weak, we observed simultaneous impulsive HXR peak at 25–100 keV and strong EUV emission. (2) In the impulsive phase, when H, UV and SXR emissions were rising to the maxima, the EUV emission was very weak. (3) During the main phase, when SXR emission was decaying, a peak in the EUV emission was observed which was substantially delayed by 7 min compared to emissions from other wavelengths. Based on our observations, we propose that the `pre-flare' phase in this event was a separate energy release process rather than a mere pre-cursor of the flare, and it is likely that the `pre-flare' EUV emission was due to weak in situ heating of low-lying coronal loops. The mechanism of the EUV emission in the main phase is investigated. It is suggested that the delayed EUV emission may come from cooling of SXR loops. 相似文献
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79.
This paper presents a generic method to automatically segment and characterize solar filaments from various Hα full-disk solar
images, obtained by different solar observatories, with different dynamic ranges and statistical properties. First, a cascading
Hough circle detector is designed to find the center location and radius of the solar disks. Second, polynomial surface fitting
is adopted to correct unbalanced luminance. Third, an adaptive thresholding method is put forward to segment solar filaments.
Finally, for each piece of a solar filament, its centroid location, area, and length are characterized, in which morphological
thinning and graph theory are used for identifying the main skeletons of filaments. To test the performance of the proposed
methods, a dataset composed of 125 Hα images is considered. These images were obtained by four solar observatories from January
2000 to May 2010, one image per month. Experimental results show that the accuracy rate is above 95% as measured by filament
number and above 99% as measured by filament area, indicating that only a few tiny filaments are not detected. 相似文献