The content of organic carbon （OC） normalized to the specific surface area （SSA） of sediment is widely used to trace variations in OC loading （OC/SSA）. This study presents observations of OC/SSA of surface sedim...The content of organic carbon （OC） normalized to the specific surface area （SSA） of sediment is widely used to trace variations in OC loading （OC/SSA）. This study presents observations of OC/SSA of surface sediments collected in the Chukchi Sea, a typical Arctic marginal sea. Shelf sediments exhibit much higher OC/SSA values than slope sediments in the study area. Compared with OC/SSA values reported from the East Siberian Shelf and Mackenzie River, the slope sediments possess lower OC loading. This abrupt decrease in OC/SSA is mostly related to the lower primary production on slope as well as possible oxidization processes. The results of linear regression analysis between OC and SSA indicate a sedimentary source rock for the OC in the Chukchi Sea sediments. Moreover, shelf sediments with low SSA possess a larger rock OC fraction than slope sediments do. The dataset of the present study enables a more thorough understanding of regional OC cycling in the Chukchi Sea.展开更多
In order to employ cost effective frequency domain analysis for off-shore structures treatment of hydrodynamic loading is essential. Drag and inertia dominated, resonating and antiresonating cases under random sea sta...In order to employ cost effective frequency domain analysis for off-shore structures treatment of hydrodynamic loading is essential. Drag and inertia dominated, resonating and antiresonating cases under random sea states are analyzed to highlight the implications and relative merits of four salient linearization techniques.展开更多
Hardened cement paste was subjected to the flexural loading and wet-dry cycles in sea water. The degradation of microstructures was obtained using scanning electron microscope （SEM）, and the energy dispersive spectr...Hardened cement paste was subjected to the flexural loading and wet-dry cycles in sea water. The degradation of microstructures was obtained using scanning electron microscope （SEM）, and the energy dispersive spectrum （EDS） analysis was carried to analyze the local composition. Mercury intrusion porosimetry （Poremaster GT-60） was used to analyze the degradation of pore structures. The experimental results show that the synergistic action of the flexural loading, wet-dry cycles and sea water leads to significant deterioration of hardened cement paste. The degradation of microstructures in the tensile region is more serious than that in the compressive region. The flexural loading and wet-dry cycles accelerate the chemical attack of sea water.展开更多
深海抗风浪网箱养殖区别于传统近海网箱、围栏等养殖方式,适合发展高经济价值的鱼类养殖,现已成为沿海渔民转产转业的重要方向。为缓解近岸养殖压力、拓宽深海水域养殖,基于中国海域养殖条件,设计了一种可以应对恶劣海况条件的新型复式...深海抗风浪网箱养殖区别于传统近海网箱、围栏等养殖方式,适合发展高经济价值的鱼类养殖,现已成为沿海渔民转产转业的重要方向。为缓解近岸养殖压力、拓宽深海水域养殖,基于中国海域养殖条件,设计了一种可以应对恶劣海况条件的新型复式抗风浪深海养殖网箱。该网箱放弃了传统的浮架和浮圈结构,采用双浮筒可调节结构,以适应不同海域海浪状况,减少因刚性连接而发生的中拱和中垂现象;此外,浮筒与立体浮框连接而成的垂荡体可以提供较大的垂荡以及纵向摇摆阻尼,控制网箱的运动幅度。同时采用莫里森公式和伯努利方程对网箱承受的风、浪、流等环境载荷进行受力计算,并与传统高密度聚乙烯(High density polyethylene,HDPE)网箱进行对比,结果显示新型复式抗风浪网箱比传统HDPE网箱更能承受海洋中的环境负载。研究结果为后续研究和发展大型抗风浪网箱养殖提供了设计参考。展开更多
For ship structural design and good maneuverability in an ice-covered sea, the local and global load of ice cover on ships should be well understood. This paper reviews the extensive work done on ice loads on ships, i...For ship structural design and good maneuverability in an ice-covered sea, the local and global load of ice cover on ships should be well understood. This paper reviews the extensive work done on ice loads on ships, including： （a） Ice pressure and local load determination based on field and model tests; （b） Global ice loads on ships from full-scale field observations, model tests and numerical models under different ice conditions （level ice and pack ice） and ship operations （maneuvering and mooring）. Spe- cial attention is paid to the discrete element simulation of global ice loads on ships; and （c） Analytical solutions and numerical models of impact loads of icebergs on ships for polar navigation. Finally, research potential in these areas is discussed.展开更多
The distribution of metals (Cd, Cr, Pb, Cu, Ni and Zn) was determined in sediment cores collected from five major areas representing different anthropogenic activities along the Jordanian coast during 27 February-11 M...The distribution of metals (Cd, Cr, Pb, Cu, Ni and Zn) was determined in sediment cores collected from five major areas representing different anthropogenic activities along the Jordanian coast during 27 February-11 March 2008. Metal concentrations in these sediments were relatively low compared to reported values from polluted areas. At some of the sites metal concentrations showed fluctuations with depth in the core suggesting changes in metal loading with time. The calculated contamination factors (CFs) for the suite of metals decreased in the following order Cd > Pb > Cr > Ni >Zn > Cu. The Pollution Loading Index (PLI) calculated for the different areas were highest at Phosphate Loading Berth (0.008, 0.2607, 0.0161, 0.007, 47.9375 and 0.0296 for Cu, Pb, Ni, Zn, Cd and Cr, respectively) and lowest at Hotel Area (0.0001, 0.0075, 0.0008, 0.0006, 1.0483 and 0.0005 for Cu, Pb, Ni, Zn, Cd and Cr, respectively) with others sites between these extremes. Result of this study could be used to assess the magnitude of pollution at each site and guide rational management decisions. Moreover, the data constitutes a baseline against which future anthropogenic effects can be assessed.展开更多
A hardware-in-the-loop (HWIL) simulator for gun servo system is described in this paper, and its load modeling technologies,such as road spectrum model,sea wave model are studied. The simulation results show that the ...A hardware-in-the-loop (HWIL) simulator for gun servo system is described in this paper, and its load modeling technologies,such as road spectrum model,sea wave model are studied. The simulation results show that the models can be used in HWIL and satisfy the requirements of hardware-in-the-loop simulator of gun servo system.展开更多
The knowledge of the wave-induced hydrodynamic loads on coastal dikes including their temporal and spatial resolution on the dike in combination with actual water levels is of crucial importance of any risk-based earl...The knowledge of the wave-induced hydrodynamic loads on coastal dikes including their temporal and spatial resolution on the dike in combination with actual water levels is of crucial importance of any risk-based early warning system. As a basis for the assessment of the wave-induced hydrodynamic loads, an operational wave now-and forecast system is set up that consists of i) available field measurements from the federal and local authorities and ii) data from numerical simulation of waves in the German Bight using the SWAN wave model. In this study, results of the hindcast of deep water wave conditions during the winter storm on 5–6 December, 2013(German name ‘Xaver') are shown and compared with available measurements. Moreover field measurements of wave run-up from the local authorities at a sea dike on the German North Sea Island of Pellworm are presented and compared against calculated wave run-up using the Eur Otop(2016) approach.展开更多
基金The National Natural Science Foundation of China under contract Nos 41606211,41276198,41406217 and 41306200the China Polar Environment Comprehensive Investigation and Assessment Programs under contract Nos Chinare-03-04 and Chinare-04-03+1 种基金the National Science Foundation for Post-doctoral Scientists of China under contract No.2016M591968the Scientific Research Fund of Second Institute of Oceanography,SOA under contract No.JG1502
文摘The content of organic carbon （OC） normalized to the specific surface area （SSA） of sediment is widely used to trace variations in OC loading （OC/SSA）. This study presents observations of OC/SSA of surface sediments collected in the Chukchi Sea, a typical Arctic marginal sea. Shelf sediments exhibit much higher OC/SSA values than slope sediments in the study area. Compared with OC/SSA values reported from the East Siberian Shelf and Mackenzie River, the slope sediments possess lower OC loading. This abrupt decrease in OC/SSA is mostly related to the lower primary production on slope as well as possible oxidization processes. The results of linear regression analysis between OC and SSA indicate a sedimentary source rock for the OC in the Chukchi Sea sediments. Moreover, shelf sediments with low SSA possess a larger rock OC fraction than slope sediments do. The dataset of the present study enables a more thorough understanding of regional OC cycling in the Chukchi Sea.
文摘In order to employ cost effective frequency domain analysis for off-shore structures treatment of hydrodynamic loading is essential. Drag and inertia dominated, resonating and antiresonating cases under random sea states are analyzed to highlight the implications and relative merits of four salient linearization techniques.
基金Founded by the Western traffic Project under the Ministry of Communications of China (No. 200631822302-03)the China National Natural Science Foundation (No. 50808045)
文摘Hardened cement paste was subjected to the flexural loading and wet-dry cycles in sea water. The degradation of microstructures was obtained using scanning electron microscope （SEM）, and the energy dispersive spectrum （EDS） analysis was carried to analyze the local composition. Mercury intrusion porosimetry （Poremaster GT-60） was used to analyze the degradation of pore structures. The experimental results show that the synergistic action of the flexural loading, wet-dry cycles and sea water leads to significant deterioration of hardened cement paste. The degradation of microstructures in the tensile region is more serious than that in the compressive region. The flexural loading and wet-dry cycles accelerate the chemical attack of sea water.
文摘深海抗风浪网箱养殖区别于传统近海网箱、围栏等养殖方式,适合发展高经济价值的鱼类养殖,现已成为沿海渔民转产转业的重要方向。为缓解近岸养殖压力、拓宽深海水域养殖,基于中国海域养殖条件,设计了一种可以应对恶劣海况条件的新型复式抗风浪深海养殖网箱。该网箱放弃了传统的浮架和浮圈结构,采用双浮筒可调节结构,以适应不同海域海浪状况,减少因刚性连接而发生的中拱和中垂现象;此外,浮筒与立体浮框连接而成的垂荡体可以提供较大的垂荡以及纵向摇摆阻尼,控制网箱的运动幅度。同时采用莫里森公式和伯努利方程对网箱承受的风、浪、流等环境载荷进行受力计算,并与传统高密度聚乙烯(High density polyethylene,HDPE)网箱进行对比,结果显示新型复式抗风浪网箱比传统HDPE网箱更能承受海洋中的环境负载。研究结果为后续研究和发展大型抗风浪网箱养殖提供了设计参考。
基金supported by the Ocean Public Welfare Scientific Research Project of China (Grant No. 201105016,2012418007)the National Natural Science Foundation of China (Grant No.41176012)the American Bureau of Shipping (ABS)
文摘For ship structural design and good maneuverability in an ice-covered sea, the local and global load of ice cover on ships should be well understood. This paper reviews the extensive work done on ice loads on ships, including： （a） Ice pressure and local load determination based on field and model tests; （b） Global ice loads on ships from full-scale field observations, model tests and numerical models under different ice conditions （level ice and pack ice） and ship operations （maneuvering and mooring）. Spe- cial attention is paid to the discrete element simulation of global ice loads on ships; and （c） Analytical solutions and numerical models of impact loads of icebergs on ships for polar navigation. Finally, research potential in these areas is discussed.
文摘The distribution of metals (Cd, Cr, Pb, Cu, Ni and Zn) was determined in sediment cores collected from five major areas representing different anthropogenic activities along the Jordanian coast during 27 February-11 March 2008. Metal concentrations in these sediments were relatively low compared to reported values from polluted areas. At some of the sites metal concentrations showed fluctuations with depth in the core suggesting changes in metal loading with time. The calculated contamination factors (CFs) for the suite of metals decreased in the following order Cd > Pb > Cr > Ni >Zn > Cu. The Pollution Loading Index (PLI) calculated for the different areas were highest at Phosphate Loading Berth (0.008, 0.2607, 0.0161, 0.007, 47.9375 and 0.0296 for Cu, Pb, Ni, Zn, Cd and Cr, respectively) and lowest at Hotel Area (0.0001, 0.0075, 0.0008, 0.0006, 1.0483 and 0.0005 for Cu, Pb, Ni, Zn, Cd and Cr, respectively) with others sites between these extremes. Result of this study could be used to assess the magnitude of pollution at each site and guide rational management decisions. Moreover, the data constitutes a baseline against which future anthropogenic effects can be assessed.
文摘A hardware-in-the-loop (HWIL) simulator for gun servo system is described in this paper, and its load modeling technologies,such as road spectrum model,sea wave model are studied. The simulation results show that the models can be used in HWIL and satisfy the requirements of hardware-in-the-loop simulator of gun servo system.
基金the joint research project Early Dike–Sensor and Risk based Early Warning Systems for Coastal Dikes(No.03G0847C)funded by the German Ministry of Education and Research(BMBF)
文摘The knowledge of the wave-induced hydrodynamic loads on coastal dikes including their temporal and spatial resolution on the dike in combination with actual water levels is of crucial importance of any risk-based early warning system. As a basis for the assessment of the wave-induced hydrodynamic loads, an operational wave now-and forecast system is set up that consists of i) available field measurements from the federal and local authorities and ii) data from numerical simulation of waves in the German Bight using the SWAN wave model. In this study, results of the hindcast of deep water wave conditions during the winter storm on 5–6 December, 2013(German name ‘Xaver') are shown and compared with available measurements. Moreover field measurements of wave run-up from the local authorities at a sea dike on the German North Sea Island of Pellworm are presented and compared against calculated wave run-up using the Eur Otop(2016) approach.
