In this paper, the long-term statistical properties of wave height in an idealized square harbor with a partial opening are studied. The incident waves are propagated into the harbor numerically by the finite/infinite...In this paper, the long-term statistical properties of wave height in an idealized square harbor with a partial opening are studied. The incident waves are propagated into the harbor numerically by the finite/infinite element method using three different wave models: (1) monochromatic wave train, (2) long-crested random wave train, and (3) short-crested random wave train. This study shows that for a given incident wave, the wave height in the harbor is affected by the wave model used. For long-term estimation of wave height exceedance probability, it is recommended that the waves be propagated into the harbor using the random wave model, and that wave heights be computed by use of the Rayleigh probability distribution.展开更多
The“notice-necessary measures”rule began with the“notice-and-takedown”rule,which originated from the United States safe harbors rule,established to limit the liability of Internet Service Providers(ISPs)for helpin...The“notice-necessary measures”rule began with the“notice-and-takedown”rule,which originated from the United States safe harbors rule,established to limit the liability of Internet Service Providers(ISPs)for helping infringement in network infringement.China’s Tort Liability Law and Civil Code amended the“notice-and-takedown”rule so that when the right holder sends an effective notice of infringement to the ISP,the ISP shall take necessary measures more than removal to be exempted from liability.This article will discuss the transformation of the rule and types of necessary measures,and reconstruct the relationship between effectiveness of notice and types of necessary measures.展开更多
Plate culture counting and strain isolation methods were utilized to assess the species richness and abundance of planktonic and attached bacteria on glass plates in the surface and bottom seawater of Qingdao Middle H...Plate culture counting and strain isolation methods were utilized to assess the species richness and abundance of planktonic and attached bacteria on glass plates in the surface and bottom seawater of Qingdao Middle Harbor over a year,with monthly and quarterly sampling.Both species richness and bacterial numbers exhibited seasonal variations.Specifically,the abundance of attached bacteria and bacterioplankton peaked in June and July,corresponding to higher water temperatures in summer and autumn,while lower abundances were noted in January and December during cooler periods.Throughout the year,the species richness of attached bacteria consistently exceeded that of planktonic bacteria in both shallow and deep waters.Pseudoalteromonas emerged as the most prevalent genus among both planktonic and attached bacteria in surface and bottom seawater samples.Furthermore,the magnitude of changes in species richness and abundance for attached bacteria(0.66×10^(5)-15.85×10^(5)CFU/cm^(2))was greater than that observed for planktonic bacteria(0.58×10^(8)-5.33×10^(8)CFU/L).We propose that the attached bacterial populations,situated in limited microenvironments within the larger seawater ecosystem,exhibit heightened sensitivity to environmental fluctuations,resulting in more rapid shifts in population dynamics and lower ecological stability.The theoretical implications and potential applications of these findings warrant further investigation.展开更多
The Polar Regions host one of the harshest and most unique ecosystems on Earth,harboring a diverse array of micro-and macro-organisms.These inhabitants showcase remarkable taxonomic and genetic originality,presenting ...The Polar Regions host one of the harshest and most unique ecosystems on Earth,harboring a diverse array of micro-and macro-organisms.These inhabitants showcase remarkable taxonomic and genetic originality,presenting unparalleled opportunities for bioprospecting,alongside demonstrating extraordinary adaptation mechanisms for survival.展开更多
The distribution characteristics of heavy metals such as Cu, Zn, Pb, Cd, Hg. As in seawater, superficail sediments and several marine organisms of Dongzhai Harbor in Hainan were analyzed. Index methods of the single f...The distribution characteristics of heavy metals such as Cu, Zn, Pb, Cd, Hg. As in seawater, superficail sediments and several marine organisms of Dongzhai Harbor in Hainan were analyzed. Index methods of the single factor and geo-accumulation were used to assess the pollution degree of heavy metals. The results showed that the heavy metal levels in the seawater of Dongzhai Harbor accorded with the first category of the seawater except Pb, and were much lower than the fishery water quality standard; the concentration of the heavy metal in surface sediments did not exceed the national benchmark of the first-class of marine sediment quality basically, and the superficial sediments were essentially uncontaminated; the heavy metal content in wetland sediments was slightly higher than those in other typical mangrove wetland island of Hainan and marine sediments in Dongzhai Haibor, which indicated this area might has been affected by land-based pollution influence, and this should cause the attention of related departments; the heavy metal concentrations in marine organisms were up to the first category. All were not beyond the standard of non-environmental pollution aquatic products.展开更多
Temporal and spatial variations of concentrations of heavy metals including mercury （Hg）, zinc （Zn）, lead （Pb）, arsenic （As）, copper （Cu）, and cadmium （Cd） in the sediments of the Yangshan Deepwater Harbor...Temporal and spatial variations of concentrations of heavy metals including mercury （Hg）, zinc （Zn）, lead （Pb）, arsenic （As）, copper （Cu）, and cadmium （Cd） in the sediments of the Yangshan Deepwater Harbor were determined based on 6 cruises in autumn and winter, respectively, from 2010 to 2013. The results demonstrated that the overall concentrations of heavy metals were low and distributed in uniform patterns. The concentrations of Hg, Zn, Pb, and Cd in autumn were significantly higher than those in winter with small fluctuations for As and Cu in terms of seasonal variations. Results of factor analysis showed that Pb, Cd, and Zn were derived from inland industrial and shipping discharges as well as the degradation of organic pollutants in marine environment. While agricultural pollutions, cargo shifting and construction debris from reclamation projects contributed to the sources of Cu, As, and Hg. Ecological risk assessment by Mean Sediment Quality Guideline Quotient （SQG-Q） revealed that the degree for eco-risk of the sediments was low-and-moderate in autumn, higher than that in winter. Hg and Cu were the dominant eco-risk factors. The results of Index of geoaccumulation （Igeo） showed that the whole sites of the sea area were barely influenced by Hg, As, Zn, and Pb, and the extents of Cd and Cu contaminations were in low grade. Contamination degree of all the six heavy metals could be ranked as the following： Cd〉Pb〉Zn〉Hg〉As. According to the results of integrated score of factor analysis, the contamination degree for heavy metals in sediments of the Yangshan Deepwater Harbor was low, despite sites No.5, No.4 and No.3, which were heavily contaminated compared with others.展开更多
Based on the observed data in 1982 approximately 1985 at Shuidong Bay area, west Guangdong Province, the morphodynamic processes of tidal inlet and ebb-tidal delta in the barrier-lagoon system are presented, including...Based on the observed data in 1982 approximately 1985 at Shuidong Bay area, west Guangdong Province, the morphodynamic processes of tidal inlet and ebb-tidal delta in the barrier-lagoon system are presented, including the dynamic features of tides and in the tidal inlet, the regional dynamics and longshore sediment transport in the ebb-tidal delta, the genesis of the entrance bar, the recent erosion and deposition in the ebb-tidal delta and so on. The paper attempts to answer two questions, i.e., the stability of the tidal inlet and the feasibility of dredging on the entrance bar for the course of Shuidong Harbour. The results show that the stability of the tidal inlet is ideal and that dredging action on the entrance bar may be successful if dredging is deep enough and the course position reasonable.展开更多
Vacuum preloading has been widely used in harbour engineering to accelerate the consolidation of soft clay. The mechanism of the method is discussed in this paper by presenting a consolidation model under the action o...Vacuum preloading has been widely used in harbour engineering to accelerate the consolidation of soft clay. The mechanism of the method is discussed in this paper by presenting a consolidation model under the action of negative pressure. A scheme of using vacuum preloading in designing a gravity platform is proposed to strengthen the soft clay layer on which the platform will be placed. Details of a drainage system are described and the functions of the system are also discussed.展开更多
In this paper, a brief account of the characteristic features of the coast of China is given, followed by the present status and future prospects of coastal and port engineering in China, experiences gained and proble...In this paper, a brief account of the characteristic features of the coast of China is given, followed by the present status and future prospects of coastal and port engineering in China, experiences gained and problems encountered. China has attached much importance to the rehabilitation and modernization of war damaged existing ports and the construction of new ports, as well as the maintenance and strengthening of coast protection works.展开更多
The vibroflotation technique has now become a comparatively perfect method. However, the stone column driving at the sea bottom, which is liable to ebb and flood tides, is seldom tried abroad and has been tried for th...The vibroflotation technique has now become a comparatively perfect method. However, the stone column driving at the sea bottom, which is liable to ebb and flood tides, is seldom tried abroad and has been tried for the first time at home. We have designed a set of construction techniques for driving and installing stone columns at sea. These techniques have been proved successful and highly efficient by practice. At the sea bottom were conducted three groups of large-scale loading tests and the allowable bearing capacity of the composite foundation was obtained as 130 kPa, against that of the natural foundation: 50 kPa. The allowable bearing capacity of the composite foundation showed 2.6 times as much as that of the natural foundation. Also obtained was the distribution ratio of stress, n = 3. The experience and indexes, obtained from the Yantai Harbour Project, have already been justified in the application in reinforcing the coastal highway at the Huaneng Power Plant of Fuzhou City, Fujian Province.展开更多
This paper provides an overview of current seismic ground motion criteria for transportation infrastructures in USA. This is to facilitate an understanding of current seismic performance levels and design practices in...This paper provides an overview of current seismic ground motion criteria for transportation infrastructures in USA. This is to facilitate an understanding of current seismic performance levels and design practices in USA for transportation professionals world-wide, especially those in Asian and Pacific regions. Seismic vulnerability of a transportation infrastructure is determined by the risk associated with the seismic ground motion and specified performance criteria. Determining an acceptable seismic risk is a very complex task that must consider both social and economic aspects. Obviously, the amount of risk that a railway bridge can accept may be different from that of a highway bridge. The economic tolerance in one country may be different from that in another country for the same type of infrastructure. In this paper, seismic performance levels and design criteria of ground motion for highway bridges, railway bridges and ports＇ container wharves in USA are reviewed, and design examples are presented to demonstrate how to develop the code-based and site-specific design acceleration response spectra and time histories.展开更多
This paper, based on wave data measured with Type 956 Directional WAVE-TRACK Buoy System at new Dalian Port for a whole year, analyses the properties of the wave frequency spectra, and derives the formula for the freq...This paper, based on wave data measured with Type 956 Directional WAVE-TRACK Buoy System at new Dalian Port for a whole year, analyses the properties of the wave frequency spectra, and derives the formula for the frequency spectrum of wind-waves.展开更多
The boundaries of a natural harbor or artificial harbor are very complex as far as its shape and reflection condition are concerned. The schemes available for solving wave diffraction in a harbor are not very accurate...The boundaries of a natural harbor or artificial harbor are very complex as far as its shape and reflection condition are concerned. The schemes available for solving wave diffraction in a harbor are not very accurate due to the simplification of realistic boundaries into a single jetty, a gap breakwater and a detached breakwater, neglecting the reflection effect of boundaries along the quays and the shore line whose shapes are rather irregular. Physical models turn to be quite helpful and valid in this case. In the present paper a mathematical model for wave diffraction in a harbor is introduced by using the singularity distribution method which can take into account the boundaries with arbitrary rate of reflection. The present model has been applied to the estimation of wave diffraction in the harbor basin of Guangdong Dayawan Nuclear Plant, and verifications with corresponding physical models are quite favorable.展开更多
Characteristics of a natural wave cannot be successfully described by only using wave frequency spectra. In the laboratory, natural wave conditions cannot be simulated exactly by a harbor sheltering experiment with ir...Characteristics of a natural wave cannot be successfully described by only using wave frequency spectra. In the laboratory, natural wave conditions cannot be simulated exactly by a harbor sheltering experiment with irregular long-crested waves, especially since the results of diffraction tests with reflection source are often inaccurate. Only a small number of laboratories in the world have possessed a directional spectrum wave producer because of its complication and expension. This paper describes the experiment for multi-directional wave superposition of wave diffraction, with the conventional regular wave producer and one-direction irregular wave producer. The test results are of equal value with that from a directional spectra wave. This method is suitable for rational design of harbor engineering projects and can be adopted in future practice.展开更多
Based on the characteristics of waves, tidal currents, sediment and seabed evolution in the Caofeidian sea area in the Bohai Bay, a 2D sediment mathematical model of waves and tidal currents is employed to study the d...Based on the characteristics of waves, tidal currents, sediment and seabed evolution in the Caofeidian sea area in the Bohai Bay, a 2D sediment mathematical model of waves and tidal currents is employed to study the development schemes of the harbor. Verification of spring and neap tidal currents and sediment in the winter and summer of 2006 shows that the calculated values of tidal stages as well as flow velocities, flow directions and sediment concentration of 15 synchronous vertical lines are in good agreement with the measured data. Also, deposition and erosion of the sea area in front of Caofeidian ore terminal induced by suspended load under tidal currents and waves are verified; it shows that the calculated values of depth of deposition and erosion as well as their distribution are close to the measured data. Furthermore, effects of reclamation scheme of island in front of the land behind Caofeidian harbor on the hydrodynamic environment are studied, including changes of flow velocities in the deep channels at the south side of Caofeidian foreland and Laolonggou and in various harbor basins, as well as changes of deposition and erosion of seabed induced by the project.展开更多
文摘In this paper, the long-term statistical properties of wave height in an idealized square harbor with a partial opening are studied. The incident waves are propagated into the harbor numerically by the finite/infinite element method using three different wave models: (1) monochromatic wave train, (2) long-crested random wave train, and (3) short-crested random wave train. This study shows that for a given incident wave, the wave height in the harbor is affected by the wave model used. For long-term estimation of wave height exceedance probability, it is recommended that the waves be propagated into the harbor using the random wave model, and that wave heights be computed by use of the Rayleigh probability distribution.
文摘The“notice-necessary measures”rule began with the“notice-and-takedown”rule,which originated from the United States safe harbors rule,established to limit the liability of Internet Service Providers(ISPs)for helping infringement in network infringement.China’s Tort Liability Law and Civil Code amended the“notice-and-takedown”rule so that when the right holder sends an effective notice of infringement to the ISP,the ISP shall take necessary measures more than removal to be exempted from liability.This article will discuss the transformation of the rule and types of necessary measures,and reconstruct the relationship between effectiveness of notice and types of necessary measures.
基金The National Natural Science Foundation of China under contract Nos 42206126 and 42076044the Natural Science Foundation of Shandong Province under contract No.ZR2021QD099.
文摘Plate culture counting and strain isolation methods were utilized to assess the species richness and abundance of planktonic and attached bacteria on glass plates in the surface and bottom seawater of Qingdao Middle Harbor over a year,with monthly and quarterly sampling.Both species richness and bacterial numbers exhibited seasonal variations.Specifically,the abundance of attached bacteria and bacterioplankton peaked in June and July,corresponding to higher water temperatures in summer and autumn,while lower abundances were noted in January and December during cooler periods.Throughout the year,the species richness of attached bacteria consistently exceeded that of planktonic bacteria in both shallow and deep waters.Pseudoalteromonas emerged as the most prevalent genus among both planktonic and attached bacteria in surface and bottom seawater samples.Furthermore,the magnitude of changes in species richness and abundance for attached bacteria(0.66×10^(5)-15.85×10^(5)CFU/cm^(2))was greater than that observed for planktonic bacteria(0.58×10^(8)-5.33×10^(8)CFU/L).We propose that the attached bacterial populations,situated in limited microenvironments within the larger seawater ecosystem,exhibit heightened sensitivity to environmental fluctuations,resulting in more rapid shifts in population dynamics and lower ecological stability.The theoretical implications and potential applications of these findings warrant further investigation.
文摘The Polar Regions host one of the harshest and most unique ecosystems on Earth,harboring a diverse array of micro-and macro-organisms.These inhabitants showcase remarkable taxonomic and genetic originality,presenting unparalleled opportunities for bioprospecting,alongside demonstrating extraordinary adaptation mechanisms for survival.
文摘The distribution characteristics of heavy metals such as Cu, Zn, Pb, Cd, Hg. As in seawater, superficail sediments and several marine organisms of Dongzhai Harbor in Hainan were analyzed. Index methods of the single factor and geo-accumulation were used to assess the pollution degree of heavy metals. The results showed that the heavy metal levels in the seawater of Dongzhai Harbor accorded with the first category of the seawater except Pb, and were much lower than the fishery water quality standard; the concentration of the heavy metal in surface sediments did not exceed the national benchmark of the first-class of marine sediment quality basically, and the superficial sediments were essentially uncontaminated; the heavy metal content in wetland sediments was slightly higher than those in other typical mangrove wetland island of Hainan and marine sediments in Dongzhai Haibor, which indicated this area might has been affected by land-based pollution influence, and this should cause the attention of related departments; the heavy metal concentrations in marine organisms were up to the first category. All were not beyond the standard of non-environmental pollution aquatic products.
基金supported by the Study on the Analysis of the Impacts of Reclamation Engineering on Marine Ecological Environment in Yangshan Deepwater Harbor and Protecting Measures of Shanghai Municipal Science and Technology Commission (No. 12231203402)
文摘Temporal and spatial variations of concentrations of heavy metals including mercury （Hg）, zinc （Zn）, lead （Pb）, arsenic （As）, copper （Cu）, and cadmium （Cd） in the sediments of the Yangshan Deepwater Harbor were determined based on 6 cruises in autumn and winter, respectively, from 2010 to 2013. The results demonstrated that the overall concentrations of heavy metals were low and distributed in uniform patterns. The concentrations of Hg, Zn, Pb, and Cd in autumn were significantly higher than those in winter with small fluctuations for As and Cu in terms of seasonal variations. Results of factor analysis showed that Pb, Cd, and Zn were derived from inland industrial and shipping discharges as well as the degradation of organic pollutants in marine environment. While agricultural pollutions, cargo shifting and construction debris from reclamation projects contributed to the sources of Cu, As, and Hg. Ecological risk assessment by Mean Sediment Quality Guideline Quotient （SQG-Q） revealed that the degree for eco-risk of the sediments was low-and-moderate in autumn, higher than that in winter. Hg and Cu were the dominant eco-risk factors. The results of Index of geoaccumulation （Igeo） showed that the whole sites of the sea area were barely influenced by Hg, As, Zn, and Pb, and the extents of Cd and Cu contaminations were in low grade. Contamination degree of all the six heavy metals could be ranked as the following： Cd〉Pb〉Zn〉Hg〉As. According to the results of integrated score of factor analysis, the contamination degree for heavy metals in sediments of the Yangshan Deepwater Harbor was low, despite sites No.5, No.4 and No.3, which were heavily contaminated compared with others.
文摘Based on the observed data in 1982 approximately 1985 at Shuidong Bay area, west Guangdong Province, the morphodynamic processes of tidal inlet and ebb-tidal delta in the barrier-lagoon system are presented, including the dynamic features of tides and in the tidal inlet, the regional dynamics and longshore sediment transport in the ebb-tidal delta, the genesis of the entrance bar, the recent erosion and deposition in the ebb-tidal delta and so on. The paper attempts to answer two questions, i.e., the stability of the tidal inlet and the feasibility of dredging on the entrance bar for the course of Shuidong Harbour. The results show that the stability of the tidal inlet is ideal and that dredging action on the entrance bar may be successful if dredging is deep enough and the course position reasonable.
文摘Vacuum preloading has been widely used in harbour engineering to accelerate the consolidation of soft clay. The mechanism of the method is discussed in this paper by presenting a consolidation model under the action of negative pressure. A scheme of using vacuum preloading in designing a gravity platform is proposed to strengthen the soft clay layer on which the platform will be placed. Details of a drainage system are described and the functions of the system are also discussed.
基金This article is reprinted by permission from The Proceedings of Coastal & Port Engineering in Developing Countries(ISBN 7-5027-0052-8/P.17),1987,Vol.Ⅰ.
文摘In this paper, a brief account of the characteristic features of the coast of China is given, followed by the present status and future prospects of coastal and port engineering in China, experiences gained and problems encountered. China has attached much importance to the rehabilitation and modernization of war damaged existing ports and the construction of new ports, as well as the maintenance and strengthening of coast protection works.
文摘The vibroflotation technique has now become a comparatively perfect method. However, the stone column driving at the sea bottom, which is liable to ebb and flood tides, is seldom tried abroad and has been tried for the first time at home. We have designed a set of construction techniques for driving and installing stone columns at sea. These techniques have been proved successful and highly efficient by practice. At the sea bottom were conducted three groups of large-scale loading tests and the allowable bearing capacity of the composite foundation was obtained as 130 kPa, against that of the natural foundation: 50 kPa. The allowable bearing capacity of the composite foundation showed 2.6 times as much as that of the natural foundation. Also obtained was the distribution ratio of stress, n = 3. The experience and indexes, obtained from the Yantai Harbour Project, have already been justified in the application in reinforcing the coastal highway at the Huaneng Power Plant of Fuzhou City, Fujian Province.
文摘This paper provides an overview of current seismic ground motion criteria for transportation infrastructures in USA. This is to facilitate an understanding of current seismic performance levels and design practices in USA for transportation professionals world-wide, especially those in Asian and Pacific regions. Seismic vulnerability of a transportation infrastructure is determined by the risk associated with the seismic ground motion and specified performance criteria. Determining an acceptable seismic risk is a very complex task that must consider both social and economic aspects. Obviously, the amount of risk that a railway bridge can accept may be different from that of a highway bridge. The economic tolerance in one country may be different from that in another country for the same type of infrastructure. In this paper, seismic performance levels and design criteria of ground motion for highway bridges, railway bridges and ports＇ container wharves in USA are reviewed, and design examples are presented to demonstrate how to develop the code-based and site-specific design acceleration response spectra and time histories.
文摘This paper, based on wave data measured with Type 956 Directional WAVE-TRACK Buoy System at new Dalian Port for a whole year, analyses the properties of the wave frequency spectra, and derives the formula for the frequency spectrum of wind-waves.
文摘The boundaries of a natural harbor or artificial harbor are very complex as far as its shape and reflection condition are concerned. The schemes available for solving wave diffraction in a harbor are not very accurate due to the simplification of realistic boundaries into a single jetty, a gap breakwater and a detached breakwater, neglecting the reflection effect of boundaries along the quays and the shore line whose shapes are rather irregular. Physical models turn to be quite helpful and valid in this case. In the present paper a mathematical model for wave diffraction in a harbor is introduced by using the singularity distribution method which can take into account the boundaries with arbitrary rate of reflection. The present model has been applied to the estimation of wave diffraction in the harbor basin of Guangdong Dayawan Nuclear Plant, and verifications with corresponding physical models are quite favorable.
文摘Characteristics of a natural wave cannot be successfully described by only using wave frequency spectra. In the laboratory, natural wave conditions cannot be simulated exactly by a harbor sheltering experiment with irregular long-crested waves, especially since the results of diffraction tests with reflection source are often inaccurate. Only a small number of laboratories in the world have possessed a directional spectrum wave producer because of its complication and expension. This paper describes the experiment for multi-directional wave superposition of wave diffraction, with the conventional regular wave producer and one-direction irregular wave producer. The test results are of equal value with that from a directional spectra wave. This method is suitable for rational design of harbor engineering projects and can be adopted in future practice.
基金The project is financially supported by the National key Basic Research and Development Program(973 Program,No.2003CB415206)the National Natural Science Foundation of China (Grant No.50379027)
文摘Based on the characteristics of waves, tidal currents, sediment and seabed evolution in the Caofeidian sea area in the Bohai Bay, a 2D sediment mathematical model of waves and tidal currents is employed to study the development schemes of the harbor. Verification of spring and neap tidal currents and sediment in the winter and summer of 2006 shows that the calculated values of tidal stages as well as flow velocities, flow directions and sediment concentration of 15 synchronous vertical lines are in good agreement with the measured data. Also, deposition and erosion of the sea area in front of Caofeidian ore terminal induced by suspended load under tidal currents and waves are verified; it shows that the calculated values of depth of deposition and erosion as well as their distribution are close to the measured data. Furthermore, effects of reclamation scheme of island in front of the land behind Caofeidian harbor on the hydrodynamic environment are studied, including changes of flow velocities in the deep channels at the south side of Caofeidian foreland and Laolonggou and in various harbor basins, as well as changes of deposition and erosion of seabed induced by the project.
