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Water purification with sintered porous materials fabricated at 400℃ from sea bottom sediments 被引量:2
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作者 DABWAN Ahmed H A IMAI Daizo +5 位作者 KANECO Satoshi SENMATSU Isamu NAKAHAMA Katsuyuki KATSUMATA Hideyuki SUZUKI Tohru OHTA Kiyohisa 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2008年第2期172-176,共5页
A sintering technology for preparing porous materials from sea bottom sediments was developed for use in water purification. The purpose of the present study was to develop methods for converting the sea bottom sedime... A sintering technology for preparing porous materials from sea bottom sediments was developed for use in water purification. The purpose of the present study was to develop methods for converting the sea bottom sediments dredged from Ago Bay into value-added recycled products. The sintered products fabricated at 400℃ were found to be very effective adsorbents for the removal of heavy metals. 展开更多
关键词 sintering preparation technology porous materials sea bottom sediments water purification heavy metals
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Temperature inversion in the Huanghai Sea bottom cold water in summer 被引量:1
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作者 YUAN Dongliang LI Yao +1 位作者 QIAO Fangli ZHAO Wei 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2013年第3期42-47,共6页
Using conductivity-Temperature-depth data of a recent cruise during July 22-28, 2008 and historical data, it is found that temperature inversions occur from time to time in the Huanghai Sea(Yellow Sea) cold water ma... Using conductivity-Temperature-depth data of a recent cruise during July 22-28, 2008 and historical data, it is found that temperature inversions occur from time to time in the Huanghai Sea(Yellow Sea) cold water mass (HSCWM) in summer. The temperature inversions are produced by the movement of the fresh and cold HSCWM masses above the warm and saline Huanghai Sea Warm Current water at the central bottom of the Huanghai Sea Trough. The non-homogeneous profiles of the temperature and the salinity suggest that vertical mixing in the HSCWM, which is of great importance to the circulation in the Huanghai Sea in summer, is weak. Trajectories of satellite-tracked surface drifters suggest that waters in the northern reach of the Huanghai Sea move southward along the 40-50 m isobaths and descend into the southern Huanghai Sea to form the western core of the HSCWM. 展开更多
关键词 temperature inversion Huanghai sea bottom cold water Huanghai sea cold water mass sum-mer
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Investigation on Touching Sea Bottom by a FPSO in Bohai Oilfield with Shallow Water
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作者 李欣 杨建民 范模 《Marine Science Bulletin》 CAS 2005年第1期10-20,共11页
As one of the key safety problems, the motion performance and touching sea bottom of a FPSO are paid much attention by the ocean oil companies when the FPSO is exposed to survival storms in the shallow-water working a... As one of the key safety problems, the motion performance and touching sea bottom of a FPSO are paid much attention by the ocean oil companies when the FPSO is exposed to survival storms in the shallow-water working areas. In this paper, time-domain numerical simulations are carried out on a 160 kDWT FPSO with a Yoke mooring system moored in the BZ25-1 oilfield with a water depth of 16.7m. The results are compared with those of the corresponding model tests. Good agreement shows that the time-domain simulations can be used to predict the performance of the FPSO in shallow-water reasonably. It is found that the touch of seabed by a fully loaded FPSO occurred few times under survival storm conditions. Therefore, the FPSO should be less loaded than that in the fully loaded condition under the survival storms. 展开更多
关键词 F PSO shallow water time-domain simulation touching sea bottom
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The diel vertical migration of the sound-scattering layer in the Yellow Sea Bottom Cold Water of the southeastern Yellow Sea: focus on its relationship with a temperature structure
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作者 LEE Hyungbeen CHO Sungho +1 位作者 KIM Woongseo KANG Donhyug 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2013年第9期44-49,共6页
Using the hydroacoustic method with a 200 kHz scientific echo sounding system, the diel vertical migration (DVM) of the sound-scatteringlayer (SSL) in the Yellow Sea Bottom Cold Water (YSBCW) of the southeastern... Using the hydroacoustic method with a 200 kHz scientific echo sounding system, the diel vertical migration (DVM) of the sound-scatteringlayer (SSL) in the Yellow Sea Bottom Cold Water (YSBCW) of the southeastern Yellow Sea was studied in April (spring) and August (summer) of 2010 and 2011. For each survey, 13-27 hours of acoustic data were continuously collected at a stationary station. The acoustic volume scattering strength (Sv) data were analyzed with temperature profile data. In the spring of both 2010 and 2011, the SSL clearly showed the vertical migration throughout the entire water column, moving from the surface layer at night to near the bottom during the day. Conductivity, temperature, and depth data indicated that the entire water column was well mixed with low temperature of about 8℃. However, the SSL showed different patterns in the summers of 2010 and 2011. In the summer of 2010 (≈28℃ at the surface), the SSL migrated to near the bottom during the day, but there were two SSLs above and below the thermocline at depth of 10-30 m at night. In the summer of 2011 (≈20℃ at the surface), the SSL extended throughout the entire water column at night, possibly owing to an abrupt change in sea weather conditions caused by the passage of a Typhoon Muifa over the study area. It was cancluded that the DVM patterns in summer in the YSBCW area may be greatly influenced by a strengthened or weakened thermocline. 展开更多
关键词 diel vertical migration sound-scattering layer temperature structure TYPHOON Yellow sea Bot- tom Cold Water
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EFFECTS OF ANAEROBE IN SEA BOTTOM SEDIMENT ON THE CORROSION OF CARBON STEEL
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作者 马士德 黄彦良 +2 位作者 朱素兰 孙嘉瑞 杜爱玲 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 1998年第4期377-380,共0页
This in situ corrosion study of steel in sea bottom sediment by the "Plate TransplantingBurying Method" (MD method ) showed that the corrosion rate of steel in sea bottom sediment with sulfur reduction bacte... This in situ corrosion study of steel in sea bottom sediment by the "Plate TransplantingBurying Method" (MD method ) showed that the corrosion rate of steel in sea bottom sediment with sulfur reduction bacteria (SRB) can be as high as ten times that in sea bottom sediment without SRB . The ex-periments in simulating sea bottom sediments with different concentrations of cultured SRB showed that theelectrochemical polarization behaviour of steel in sea bottom sediment with and without SRB were differ-ent SRB altered the polarization behaviour of steel significantly by acididfying the environment so that ap-parent hydrogen depolarization occurred and accelerated the corrosion of steel. 展开更多
关键词 ANAEROBE sea bottom SEDIMENT steel
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Seismic monitoring of sub-seafloor fluid processes in the Haima cold seep area using an Ocean Bottom Seismometer (OBS) 被引量:3
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作者 Bin Liu JianYu Huang +2 位作者 WenBin Jiang WeiWei Wang Li Yang 《Earth and Planetary Physics》 CAS CSCD 2023年第5期582-602,共21页
The use of ocean bottom seismometers provides an effective means of studying the process and the dynamic of cold seeps by continuously recording micro-events produced by sub-seafloor fluid migration.We deployed a four... The use of ocean bottom seismometers provides an effective means of studying the process and the dynamic of cold seeps by continuously recording micro-events produced by sub-seafloor fluid migration.We deployed a four-component Ocean Bottom Seismometer(OBS)at an active site of the Haima cold seep from 6 November to 19 November in 2021.Here,we present the results of this short-term OBS monitoring.We first examine the OBS record manually to distinguish(by their distinctive seismographic signatures)four types of events:shipping noises,vibrations from our remotely operated vehicle(ROV)operations,local earthquakes,and short duration events(SDEs).Only the SDEs are further discussed in this work.Such SDEs are similar to those observed in other sea areas and are interpreted to be correlated with sub-seafloor fluid migration.In the OBS data collected during the 14-day monitoring period.We identify five SDEs.Compared to the SDE occurrence rate observed in other cold seep regions,five events is rather low,from which it could be inferred that fluid migration,and subsequent gas seepage,is not very active at the Haima site.This conclusion agrees with multi-beam and chemical observations at that site.Our observations thus provide further constraint on the seepage activity in this location.This is the first time that cold seep-related SDEs have been identified in the South China Sea,expanding the list of sea areas where SDEs are now linked to cold seep fluid migration. 展开更多
关键词 cold seep OBS(Ocean bottom Seismometer) SDE(short duration event) Haima South China sea
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A comparison study on structure-function relationship of polysaccharides obtained from sea buckthorn berries using different methods:antioxidant and bile acid-binding capacity 被引量:4
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作者 Qiaoyun Li Zuman Dou +5 位作者 Qingfei Duan Chun Chen Ruihai Liu Yueming Jiang Bao Yang Xiong Fu 《Food Science and Human Wellness》 SCIE CSCD 2024年第1期494-505,共12页
In this study,the structural characters,antioxidant activities and bile acid-binding ability of sea buckthorn polysaccharides(HRPs)obtained by the commonly used hot water(HRP-W),pressurized hot water(HRP-H),ultrasonic... In this study,the structural characters,antioxidant activities and bile acid-binding ability of sea buckthorn polysaccharides(HRPs)obtained by the commonly used hot water(HRP-W),pressurized hot water(HRP-H),ultrasonic(HRP-U),acid(HRP-C)and alkali(HRP-A)assisted extraction methods were investigated.The results demonstrated that extraction methods had significant effects on extraction yield,monosaccharide composition,molecular weight,particle size,triple-helical structure,and surface morphology of HRPs except for the major linkage bands.Thermogravimetric analysis showed that HRP-U with filamentous reticular microstructure exhibited better thermal stability.The HRP-A with the lowest molecular weight and highest arabinose content possessed the best antioxidant activities.Moreover,the rheological analysis indicated that HRPs with higher galacturonic acid content and molecular weight showed higher viscosity and stronger crosslinking network(HRP-C,HRP-W and HRP-U),which exhibited stronger bile acid binding capacity.The present findings provide scientific evidence in the preparation technology of sea buckthorn polysaccharides with good antioxidant and bile acid binding capacity which are related to the structure affected by the extraction methods. 展开更多
关键词 sea buckthorn Extraction method STRUCTURE Rheological properties Antioxidant activity Bile acid binding capacity
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Influence of Irregular Coastlines on a Tornadic Mesovortex in the Pearl River Delta during the Monsoon Season. Part Ⅰ:Pre-storm Environment and Storm Evolution 被引量:1
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作者 Lanqiang BAI Dan YAO +4 位作者 Zhiyong MENG Yu ZHANG Xianxiang HUANG Zhaoming LI Xiaoding YU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第6期1115-1131,共17页
The Pearl River Delta(PRD),a tornado hotspot,forms a distinct trumpet-shaped coastline that concaves toward the South China Sea.During the summer monsoon season,low-level southwesterlies over the PRD’s sea surface te... The Pearl River Delta(PRD),a tornado hotspot,forms a distinct trumpet-shaped coastline that concaves toward the South China Sea.During the summer monsoon season,low-level southwesterlies over the PRD’s sea surface tend to be turned toward the west coast,constituting a convergent wind field along with the landward-side southwesterlies,which influences regional convective weather.This two-part study explores the roles of this unique land–sea contrast of the trumpet-shaped coastline in the formation of a tornadic mesovortex within monsoonal flows in this region.Part I primarily presents observational analyses of pre-storm environments and storm evolutions.The rotating storm developed in a lowshear environment(not ideal for a supercell)under the interactions of three air masses under the influence of the land–sea contrast,monsoon,and storm cold outflows.This intersection zone(or“triple point”)is typically characterized by local enhancements of ambient vertical vorticity and convergence.Based on a rapid-scan X-band phased-array radar,finger-like echoes were recognized shortly after the gust front intruded on the triple point.Developed over the triple point,they rapidly wrapped up with a well-defined low-level mesovortex.It is thus presumed that the triple point may have played roles in the mesovortex genesis,which will be demonstrated in Part II with multiple sensitivity numerical simulations.The findings also suggest that when storms pass over the boundary intersection zone in the PRD,the expected possibility of a rotating storm occurring is relatively high,even in a low-shear environment.Improved knowledge of such environments provides additional guidance to assess the regional tornado risk. 展开更多
关键词 TORNADO mesovortex surface boundary land–sea contrast MONSOON
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Assessments of Data-Driven Deep Learning Models on One-Month Predictions of Pan-Arctic Sea Ice Thickness 被引量:1
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作者 Chentao SONG Jiang ZHU Xichen LI 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第7期1379-1390,共12页
In recent years,deep learning methods have gradually been applied to prediction tasks related to Arctic sea ice concentration,but relatively little research has been conducted for larger spatial and temporal scales,ma... In recent years,deep learning methods have gradually been applied to prediction tasks related to Arctic sea ice concentration,but relatively little research has been conducted for larger spatial and temporal scales,mainly due to the limited time coverage of observations and reanalysis data.Meanwhile,deep learning predictions of sea ice thickness(SIT)have yet to receive ample attention.In this study,two data-driven deep learning(DL)models are built based on the ConvLSTM and fully convolutional U-net(FC-Unet)algorithms and trained using CMIP6 historical simulations for transfer learning and fine-tuned using reanalysis/observations.These models enable monthly predictions of Arctic SIT without considering the complex physical processes involved.Through comprehensive assessments of prediction skills by season and region,the results suggest that using a broader set of CMIP6 data for transfer learning,as well as incorporating multiple climate variables as predictors,contribute to better prediction results,although both DL models can effectively predict the spatiotemporal features of SIT anomalies.Regarding the predicted SIT anomalies of the FC-Unet model,the spatial correlations with reanalysis reach an average level of 89%over all months,while the temporal anomaly correlation coefficients are close to unity in most cases.The models also demonstrate robust performances in predicting SIT and SIE during extreme events.The effectiveness and reliability of the proposed deep transfer learning models in predicting Arctic SIT can facilitate more accurate pan-Arctic predictions,aiding climate change research and real-time business applications. 展开更多
关键词 Arctic sea ice thickness deep learning spatiotemporal sequence prediction transfer learning
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Arctic Sea Ice Variations in the First Half of the 20th Century:A New Reconstruction Based on Hydrometeorological Data 被引量:1
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作者 Vladimir A.SEMENOV Tatiana A.ALDONINA +2 位作者 Fei LI Noel Sebastian KEENLYSIDE Lin WANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第8期1483-1495,1686-1693,共21页
The shrinking Arctic sea-ice area(SIA) in recent decades is a striking manifestation of the ongoing climate change.Variations of the Arctic sea ice have been continuously observed by satellites since 1979, relatively ... The shrinking Arctic sea-ice area(SIA) in recent decades is a striking manifestation of the ongoing climate change.Variations of the Arctic sea ice have been continuously observed by satellites since 1979, relatively well monitored since the 1950s, but are highly uncertain in the earlier period due to a lack of observations. Several reconstructions of the historical gridded sea-ice concentration(SIC) data were recently presented based on synthesized regional sea-ice observations or by applying a hybrid model–empirical approach. Here, we present an SIC reconstruction for the period1901–2019 based on established co-variability between SIC and surface air temperature, sea surface temperature, and sea level pressure patterns. The reconstructed sea-ice data for March and September are compared to the frequently used Had ISST1.1 and SIBT1850 datasets. Our reconstruction shows a large decrease in SIA from the 1920 to 1940 concurrent with the Early 20th Century Warming event in the Arctic. Such a negative SIA anomaly is absent in Had ISST1.1 data. The amplitude of the SIA anomaly reaches about 0.8 mln km^(2) in March and 1.5 mln km^(2) in September. The anomaly is about three times stronger than that in the SIBT1850 dataset. The larger decrease in SIA in September is largely due to the stronger SIC reduction in the western sector of the Arctic Ocean in the 70°–80°N latitudinal zone. Our reconstruction provides gridded monthly data that can be used as boundary conditions for atmospheric reanalyses and model experiments to study the Arctic climate for the first half of the 20th century. 展开更多
关键词 Arctic sea ice Arctic climate early 20th century warming climate variability
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Projecting Wintertime Newly Formed Arctic Sea Ice through Weighting CMIP6 Model Performance and Independence 被引量:1
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作者 Jiazhen ZHAO Shengping HE +2 位作者 Ke FAN Huijun WANG Fei LI 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第8期1465-1482,共18页
Precipitous Arctic sea-ice decline and the corresponding increase in Arctic open-water areas in summer months give more space for sea-ice growth in the subsequent cold seasons. Compared to the decline of the entire Ar... Precipitous Arctic sea-ice decline and the corresponding increase in Arctic open-water areas in summer months give more space for sea-ice growth in the subsequent cold seasons. Compared to the decline of the entire Arctic multiyear sea ice,changes in newly formed sea ice indicate more thermodynamic and dynamic information on Arctic atmosphere–ocean–ice interaction and northern mid–high latitude atmospheric teleconnections. Here, we use a large multimodel ensemble from phase 6 of the Coupled Model Intercomparison Project(CMIP6) to investigate future changes in wintertime newly formed Arctic sea ice. The commonly used model-democracy approach that gives equal weight to each model essentially assumes that all models are independent and equally plausible, which contradicts with the fact that there are large interdependencies in the ensemble and discrepancies in models' performances in reproducing observations. Therefore, instead of using the arithmetic mean of well-performing models or all available models for projections like in previous studies, we employ a newly developed model weighting scheme that weights all models in the ensemble with consideration of their performance and independence to provide more reliable projections. Model democracy leads to evident bias and large intermodel spread in CMIP6 projections of newly formed Arctic sea ice. However, we show that both the bias and the intermodel spread can be effectively reduced by the weighting scheme. Projections from the weighted models indicate that wintertime newly formed Arctic sea ice is likely to increase dramatically until the middle of this century regardless of the emissions scenario.Thereafter, it may decrease(or remain stable) if the Arctic warming crosses a threshold(or is extensively constrained). 展开更多
关键词 wintertime newly formed Arctic sea ice model democracy model weighting scheme model performance model independence
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Relative Impacts of Sea Ice Loss and Atmospheric Internal Variability on the Winter Arctic to East Asian Surface Air Temperature Based on Large-Ensemble Simulations with NorESM2 被引量:1
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作者 Shengping HE Helge DRANGE +4 位作者 Tore FUREVIK Huijun WANG Ke FAN Lise Seland GRAFF Yvan J.ORSOLINI 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第8期1511-1526,共16页
To quantify the relative contributions of Arctic sea ice and unforced atmospheric internal variability to the “warm Arctic, cold East Asia”(WACE) teleconnection, this study analyses three sets of large-ensemble simu... To quantify the relative contributions of Arctic sea ice and unforced atmospheric internal variability to the “warm Arctic, cold East Asia”(WACE) teleconnection, this study analyses three sets of large-ensemble simulations carried out by the Norwegian Earth System Model with a coupled atmosphere–land surface model, forced by seasonal sea ice conditions from preindustrial, present-day, and future periods. Each ensemble member within the same set uses the same forcing but with small perturbations to the atmospheric initial state. Hence, the difference between the present-day(or future) ensemble mean and the preindustrial ensemble mean provides the ice-loss-induced response, while the difference of the individual members within the present-day(or future) set is the effect of atmospheric internal variability. Results indicate that both present-day and future sea ice loss can force a negative phase of the Arctic Oscillation with a WACE pattern in winter. The magnitude of ice-induced Arctic warming is over four(ten) times larger than the ice-induced East Asian cooling in the present-day(future) experiment;the latter having a magnitude that is about 30% of the observed cooling. Sea ice loss contributes about 60%(80%) to the Arctic winter warming in the present-day(future) experiment. Atmospheric internal variability can also induce a WACE pattern with comparable magnitudes between the Arctic and East Asia. Ice-lossinduced East Asian cooling can easily be masked by atmospheric internal variability effects because random atmospheric internal variability may induce a larger magnitude warming. The observed WACE pattern occurs as a result of both Arctic sea ice loss and atmospheric internal variability, with the former dominating Arctic warming and the latter dominating East Asian cooling. 展开更多
关键词 Arctic sea ice loss warm Arctic–cold East Asia atmospheric internal variability large-ensemble simulation NorESM2 PAMIP
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Tide-Induced Mixing in the Bottom Boundary Layer in the Western East China Sea
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作者 GUO Zheng CAO Anzhou WANG Jianfeng 《Journal of Ocean University of China》 SCIE CAS CSCD 2023年第1期1-8,共8页
The East China Sea(ECS)boasts a vast continental shelf,where strong tidal motions play an important role in the substance transport and energy budget.In this study,the tide-induced mixing in the bottom boundary layer ... The East China Sea(ECS)boasts a vast continental shelf,where strong tidal motions play an important role in the substance transport and energy budget.In this study,the tide-induced mixing in the bottom boundary layer in the western ECS is analyzed based on records measured by moored acoustic Doppler current profilers from June to October 2014.Results show that the M_(2) tide is strong and shows a barotropic feature,whereas the O_(1) tide is much weaker.Based on the M_(2) tidal currents,the eddy viscosity in the bottom Ekman boundary layer is estimated with three schemes.The estimated eddy viscosity values vary within 10^(-4)–10^(-2)m^(2) s^(−1),reaching a maximum at approximately 5 m height from the bottom and decreasing exponentially with the height at all three stations.Moreover,the shear production of turbulent kinetic energy is calculated to quantify the mixing induced by different tidal constituents.The results show that the shear production of the M_(2) tide is much stronger than that of the O_(1) tide and shows a bottom intensified feature. 展开更多
关键词 TIDES East China sea bottom boundary layer MIXING eddy viscosity
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Physical and mechanical properties and microstructures of submarine soils in the Yellow Sea 被引量:1
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作者 Zhuangcai Tian Yihua Chang +6 位作者 Sichao Chen Gengchen Wang Yanhong Hu Chuan Guo Lei Jia Lei Song Jianhua Yue 《Deep Underground Science and Engineering》 2024年第2期197-206,共10页
In recent years,the exploration of seabed has been intensified,but the submarine soils of silt and sand in the Yellow Sea area have not been well investigated so far.In this study,the physical and mechanical propertie... In recent years,the exploration of seabed has been intensified,but the submarine soils of silt and sand in the Yellow Sea area have not been well investigated so far.In this study,the physical and mechanical properties of silt and sand from the Yellow Sea were measured using a direct shear apparatus and their microstructures were observed using a scanning electron microscope.The test results suggest that the shear strength of silt and sand increases linearly with the increase of normal stress.Based on the direct shear test,the scanning electron microscope was used to observe the section surface of sand.It is observed that the section surface becomes rough,with many“V”‐shaped cracks.Many particles appear on the surface of the silt structure and tend to be disintegrated.The X‐ray diffraction experiment reveals that the sand and silt have different compositions.The shear strength of sand is slightly greater than that of silt under high stress,which is related to the shape of soil particles and the mineral composition.These results can be a reference for further study of other soils in the Yellow Sea;meanwhile,they can serve as soil parameters for the stability and durability analyses of offshore infrastructure construction. 展开更多
关键词 direct shear test MICROSCOPE physical properties submarine soil Yellow sea
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Spatial patterns of zooplankton abundance,biovolume,and size structure in response to environmental variables:a case study in the Yellow Sea and East China Sea
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作者 Song SUN Haochen XIAN +2 位作者 Xiaoxia SUN Mingliang ZHU Mengtan LIU 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第1期113-127,共15页
The Yellow Sea(YS)and East China Sea(ECS)are highly dynamic marginal seas of the northwestern Pacific Ocean.To gain an in-depth understanding of zooplankton community structure,zooplankton abundance,biovolume,and size... The Yellow Sea(YS)and East China Sea(ECS)are highly dynamic marginal seas of the northwestern Pacific Ocean.To gain an in-depth understanding of zooplankton community structure,zooplankton abundance,biovolume,and size structure in summer 2017 in the YS and ECS were assessed using ZooScan imaging analysis.Zooplankton abundance and biovolume ranged 2.94–1187.14 inds./m^(3)and 3.13–3438.51 mm^(3)/m^(3),respectively.Based on the biovolume data of the categorized size classes of 26 identified taxonomic groups,the zooplankton community was classified into five groups,and each group was coupled with distinctive oceanographic features.Under the influence of the Yellow Sea Cold Water Mass,the Yellow Sea offshore group featured the lowest bottom temperature(10.84±3.42℃)and the most abundant Calanoids(mainly in the 2–3 mm size class).In the Yellow Sea inshore group,Hydrozoans showed the largest biovolume and dominated in the 3–4-mm and>5-mm size classes.The East China Sea offshore group,which was affected by the Kuroshio Branch Current,featured high temperature and salinity,and the lowest bottom dissolved oxygen(2.58±0.5 mg/L).The lowest values of zooplankton abundance and biovolume in the East China Sea offshore group might be attributed to the bottom dissolved oxygen contents.The East China Sea inshore group,which was mainly influenced by the Zhejiang-Fujian Coastal Current and Changjiang Diluted Water,was characterized by high chlorophyll a and the largest biovolume of carnivorous Siphonophores(280.82±303.37 mm^(3)/m^(3)).The Changjiang River estuary offshore group showed the most abundant Cyclopoids,which might be associated with the less turbid water mass in this region.Seawater temperature was considered the most important factor in shaping the size compositions of Calanoids in different groups. 展开更多
关键词 ZOOPLANKTON size structure ZooScan Yellow sea East China sea
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Spatiotemporal variation and freeze-thaw asymmetry of Arctic sea ice in multiple dimensions during 1979 to 2020
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作者 Yu Guo Xiaoli Wang +1 位作者 He Xu Xiyong Hou 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2024年第3期102-114,共13页
Arctic sea ice is broadly regarded as an indicator and amplifier of global climate change.The rapid changes in Arctic sea ice have been widely concerned.However,the spatiotemporal changes in the horizontal and vertica... Arctic sea ice is broadly regarded as an indicator and amplifier of global climate change.The rapid changes in Arctic sea ice have been widely concerned.However,the spatiotemporal changes in the horizontal and vertical dimensions of Arctic sea ice and its asymmetry during the melt and freeze seasons are rarely quantified simultaneously based on multiple sources of the same long time series.In this study,the spatiotemporal variation and freeze-thaw asymmetry of Arctic sea ice were investigated from both the horizontal and vertical dimensions during 1979–2020 based on remote sensing and assimilation data.The results indicated that Arctic sea ice was declining at a remarkably high rate of–5.4×10^(4) km^(2)/a in sea ice area(SIA)and–2.2 cm/a in sea ice thickness(SIT)during 1979 to 2020,and the reduction of SIA and SIT was the largest in summer and the smallest in winter.Spatially,compared with other sub-regions,SIA showed a sharper declining trend in the Barents Sea,Kara Sea,and East Siberian Sea,while SIT presented a larger downward trend in the northern Canadian Archipelago,northern Greenland,and the East Siberian Sea.Regarding to the seasonal trend of sea ice on sub-region scale,the reduction rate of SIA exhibited an apparent spatial heterogeneity among seasons,especially in summer and winter,i.e.,the sub-regions linked to the open ocean exhibited a higher decline rate in winter;however,the other sub-regions blocked by the coastlines presented a greater decline rate in summer.For SIT,the sub-regions such as the Beaufort Sea,East Siberian Sea,Chukchi Sea,Central Arctic,and Canadian Archipelago always showed a higher downward rate in all seasons.Furthermore,a striking freeze-thaw asymmetry of Arctic sea ice was also detected.Comparing sea ice changes in different dimensions,sea ice over most regions in the Arctic showed an early retreat and rapid advance in the horizontal dimension but late melting and gradual freezing in the vertical dimension.The amount of sea ice melting and freezing was disequilibrium in the Arctic during the considered period,and the rate of sea ice melting was 0.3×10^(4) km^(2)/a and 0.01 cm/a higher than that of freezing in the horizontal and vertical dimensions,respectively.Moreover,there were notable shifts in the melting and freezing of Arctic sea ice in 1997/2003 and 2000/2004,respectively,in the horizontal/vertical dimension. 展开更多
关键词 Arctic sea ice sea ice area sea ice thickness spatiotemporal variation freeze-thaw asymmetry
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Wintertime Arctic Sea-Ice Decline Related to Multi-Year La Niña Events
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作者 Wenxiu ZHONG Qian SHI +2 位作者 Qinghua YANG Jiping LIU Song YANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第9期1680-1690,共11页
Arctic sea ice has undergone a significant decline in the Barents-Kara Sea(BKS)since the late 1990s.Previous studies have shown that the decrease in sea ice caused by increased poleward moisture transport is modulated... Arctic sea ice has undergone a significant decline in the Barents-Kara Sea(BKS)since the late 1990s.Previous studies have shown that the decrease in sea ice caused by increased poleward moisture transport is modulated by tropical sea temperature changes(mainly referring to La Niña events).The occurrence of multi-year La Niña(MYLA)events has increased significantly in recent decades,and their impact on Arctic sea ice needs to be further explored.In this study,we investigate the relationship between sea-ice variation and different atmospheric diagnostics during MYLA and other La Niña(OTLA)years.The decline in BKS sea ice during MYLA winters is significantly stronger than that during OTLA years.This is because MYLA events tend to be accompanied by a warm Arctic-cold continent pattern with a barotropic high pressure blocked over the Urals region.Consequently,more frequent northward atmospheric rivers intrude into the BKS,intensifying longwave radiation downward to the underlying surface and melting the BKS sea ice.However,in the early winter of OTLA years,a negative North Atlantic Oscillation presents in the high latitudes of the Northern Hemisphere,which obstructs the atmospheric rivers to the south of Iceland.We infer that such a different response of BKS sea-ice decline to different La Niña events is related to stratospheric processes.Considering the rapid climate changes in the past,more frequent MYLA events may account for the substantial Arctic sea-ice loss in recent decades. 展开更多
关键词 Arctic sea ice multi-year ENSO Ural blocking atmospheric river Barents-Kara sea
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Contributors to tidal duration asymmetry with varied coastline configurations on western shelf of Yellow Sea
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作者 Xi Feng Zheng Li +3 位作者 Hui Feng Jia-yan Yang Shou-peng Xie Wei-bing Feng 《Water Science and Engineering》 EI CAS CSCD 2024年第1期1-12,共12页
Coastal management in China is confronted with an urgent choice between natural restoration and maintenance of existing seawalls and reclaimed land for economic development.A key criterion for making this decision is ... Coastal management in China is confronted with an urgent choice between natural restoration and maintenance of existing seawalls and reclaimed land for economic development.A key criterion for making this decision is the resilience to coastal flooding,which depends on the ability to predict tidal level.Tidal duration asymmetry(TDA)is a key parameter in determination of the arrival and duration of flood tides.This study selected the western inner shelf of the Yellow Sea(WYS)as the study area and investigated the responses of TDA to different shoreline configurations and relative sea level rise.The responses of TDA to shoreline reconstruction yielded spatial variability locally and remotely.In the nearshore area,the responses of TDA to the complex ocean environment mainly originated from the combined functions of reflection,bottom friction,and advection,which controlled the energy transfer from M2 or S2 constituents to their overtides or compound tides.The sensitivity of TDA to coastline typologies was not limited to coastal waters but could stretch over the entire inner shelf.The vulnerability of tidal responses was due to the displacement of the M2 amphidrome of the Kelvin wave on the WYS,which in turn changed tidal energy fluxes over the regime.The relative sea level rise could intensify the feedback of TDA to seawalls and land reclamation. 展开更多
关键词 Tidal duration asymmetry Western inner shelf of Yellow sea Natural restoration Relative sea level rise Tidal amphidrome
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Effects of Poria cocos polysaccharide on growth performance,physiological parameters,and lipid metabolism of spotted sea bass Lateolabrax maculatus
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作者 Jing LU Zhangfan HUANG +2 位作者 Youling YE Anle XU Zhongbao LI 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第1期316-331,共16页
The aquaculture industry has developed significantly over the past few decades and has had a substantial impact on the global food supply and marine fisheries resources.However,some problems arise behind the scenes du... The aquaculture industry has developed significantly over the past few decades and has had a substantial impact on the global food supply and marine fisheries resources.However,some problems arise behind the scenes due to excessive intensive farming,such as slow animal growth,frequent disease,and lipid metabolism disorders.These problems have limited the sustainable development of the aquaculture industry,and a continuable solution is required.The use of fungal polysaccharide appears to provide a solution to these problems.Therefore,different supplemented levels of Poria cocos polysaccharide(PCP)(0,0.4,0.8,1.2,1.6,and 2.0 g/kg,respectively)were fed to spotted sea bass(Lateolabrax maculatus)in similar size(30.28±0.18 g)in current study.The effects of PCP on growth,physiological parameters,and lipid metabolism of spotted sea bass were investigated after a 4-week rearing period.Results showed,fish with PCP intake presented a significantly higher weight gain,specific growth rate,and a significantly lower feed conversion ratio.Significantly higher trypsin activity in liver and intestine were observed in fish with PCP intake.The superoxide dismutase activity in serum and liver of fish with PCP intake were significantly improved,while significantly higher serum total antioxidant capacity and hepatic catalase activity were also observed.However,no significant differences in lysozyme and alkaline phosphatase activity were evident among groups.Fish with PCP intake showed a significantly lower total cholesterol,but no noteworthy change in triglyceride and lipid-metabolismrelated genes expression were observed among groups.Results indicated that intake of PCP has a positive effect on growth and antioxidant capacity of spotted sea bass,but seems to have a limited effect on the non-specific immunity and lipid metabolism of spotted sea bass.Based on the regression analysis results,1.4 g/kg of PCP is the optimal dose for spotted sea bass in size(30.28±0.18 g). 展开更多
关键词 spotted sea bass Poria cocos POLYSACCHARIDE GROWTH lipid metabolism
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Deep Learning Shows Promise for Seasonal Prediction of Antarctic Sea Ice in a Rapid Decline Scenario
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作者 Xiaoran DONG Yafei NIE +6 位作者 Jinfei WANG Hao LUO Yuchun GAO Yun WANG Jiping LIU Dake CHEN Qinghua YANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第8期1569-1573,共5页
The rapidly changing Antarctic sea ice has garnered significant interest. To enhance the prediction skill for sea ice and respond to the Sea Ice Prediction Network-South's latest call, this study presents the refo... The rapidly changing Antarctic sea ice has garnered significant interest. To enhance the prediction skill for sea ice and respond to the Sea Ice Prediction Network-South's latest call, this study presents the reforecast results of Antarctic sea-ice area and extent from December to June of the coming year with a Convolutional Long Short-Term Memory(Conv LSTM)Network. The reforecast experiments demonstrate that Conv LSTM captures the interannual and interseasonal variability of Antarctic sea ice successfully, and performs better than the European Centre for Medium-Range Weather Forecasts. Based on this, we present the prediction from December 2023 to June 2024, indicating that the Antarctic sea ice will remain at lows, but may not create a new record low. This research highlights the promising application of deep learning in Antarctic sea-ice prediction. 展开更多
关键词 deep learning ANTARCTIC sea ice seasonal prediction
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