2005 Vol. 24, No. 4
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Display Method:
2005, (4): 1-9.
Abstract:
On the basis of data of drifting bottles' tracks and the current measured in anchored stations,as well as temperature and salinity observed in cruise investigations and coastal stations,ADCP current data and AVHRR surface sea temperature(SST) data on the western coast of Guangdong,synthetic results of analysis showed that the coastal currents in the west of the mouth of the Zhujiang River were mainly westward in summer,which constituted the north branch of cyclonic gyre in the east of the Qiongzhou Straits.Part of its water flowed westward into the Beibu Gulf through the Qiongzhou Straits.The coastal current pattern was not identical with the traditional current system which flowed westward in the Qiongzhou Straits in winter and eastward in summer.The summertime's coastal current was always westward,maybe temporarily turning northeast only when the southwest wind was strong.The important characteristics of coastal current on the western coast of Guangdong,in the Qiongzhou Straits and in the north of the Beibu Gulfwere analyzed and their mechanisms also were explained.
On the basis of data of drifting bottles' tracks and the current measured in anchored stations,as well as temperature and salinity observed in cruise investigations and coastal stations,ADCP current data and AVHRR surface sea temperature(SST) data on the western coast of Guangdong,synthetic results of analysis showed that the coastal currents in the west of the mouth of the Zhujiang River were mainly westward in summer,which constituted the north branch of cyclonic gyre in the east of the Qiongzhou Straits.Part of its water flowed westward into the Beibu Gulf through the Qiongzhou Straits.The coastal current pattern was not identical with the traditional current system which flowed westward in the Qiongzhou Straits in winter and eastward in summer.The summertime's coastal current was always westward,maybe temporarily turning northeast only when the southwest wind was strong.The important characteristics of coastal current on the western coast of Guangdong,in the Qiongzhou Straits and in the north of the Beibu Gulfwere analyzed and their mechanisms also were explained.
2005, (4): 10-19.
Abstract:
On the basis of 900-year integration of a global ocean circulation model-LICOM driven by ECMWF reanalysis wind data with uniform 0.5°-grids,a quantitative estimate of the annual and monthly mean water exchange of the South China Sea(SCS) with its adjacent oceans through 5 straits is obtained.Among them,the annual transport is the largest in the Luzon Strait,then in the Taiwan Strait,and then in the Sunda Shelf,in the Balabac Strait and in the Mindoro Strait in turn,the largest monthly transport variation appears in the Luzon Strait and Sunda shelf.It is shown that the mass transport through the Taiwan Strait is affected by monsoon,while the transport through the Luzon Strait may be associated with the bifurcation position of the North Equatorial Current off the east Philippines shore;the transports in the Luzon Strait and Sunda Shelf are out of phase in direction but well correlated in magnitude.The annual and monthly mean heat and salinity exchange of the SCS through the straits are also calculated and shown to be in phase with the mass transport.The Kuroshio water carries about 0.43 PW heat transport and 151.33 kt/s salinity transport into the SCS,while most of them is carried out of the SCS through the Taiwan Strait and Sunda Shelf annually.The further model integration based on the 900-year integration for another 44 a from 1958 to 2001 driven by real wind data(ERA40 data) shows that the monthly mean mass transport via these straits varies annually with a large variation range,which may be associated with the seasonal and interannual variations in the current field and sea surface height in the SCS.The mean mass transport through the Taiwan Strait,Luzon Strait,Mindoro Strait,Balabac Strait and Sunda Shelf is 2.012×106,-4.063×106,-0.124×106,-0.083×106 and 2.258×106 m3/s,respectively.
On the basis of 900-year integration of a global ocean circulation model-LICOM driven by ECMWF reanalysis wind data with uniform 0.5°-grids,a quantitative estimate of the annual and monthly mean water exchange of the South China Sea(SCS) with its adjacent oceans through 5 straits is obtained.Among them,the annual transport is the largest in the Luzon Strait,then in the Taiwan Strait,and then in the Sunda Shelf,in the Balabac Strait and in the Mindoro Strait in turn,the largest monthly transport variation appears in the Luzon Strait and Sunda shelf.It is shown that the mass transport through the Taiwan Strait is affected by monsoon,while the transport through the Luzon Strait may be associated with the bifurcation position of the North Equatorial Current off the east Philippines shore;the transports in the Luzon Strait and Sunda Shelf are out of phase in direction but well correlated in magnitude.The annual and monthly mean heat and salinity exchange of the SCS through the straits are also calculated and shown to be in phase with the mass transport.The Kuroshio water carries about 0.43 PW heat transport and 151.33 kt/s salinity transport into the SCS,while most of them is carried out of the SCS through the Taiwan Strait and Sunda Shelf annually.The further model integration based on the 900-year integration for another 44 a from 1958 to 2001 driven by real wind data(ERA40 data) shows that the monthly mean mass transport via these straits varies annually with a large variation range,which may be associated with the seasonal and interannual variations in the current field and sea surface height in the SCS.The mean mass transport through the Taiwan Strait,Luzon Strait,Mindoro Strait,Balabac Strait and Sunda Shelf is 2.012×106,-4.063×106,-0.124×106,-0.083×106 and 2.258×106 m3/s,respectively.
2005, (4): 20-28.
Abstract:
The Louis scheme and the COARE algorithm(version 3.0) are tested against eddy covariance and inertial dissipation methods for friction velocity estimates in different wind-sea/swell regimes.Atmospheric forcing data,tabulated by Donelan et al.(1997.J Phys Oceanog,27:2 087~2 099),were collected from a mast on the foredeck ofa SWATH(small water-plane area,twin hull) ship in deep sea off the State of Virginia during the surface wave dynamics experiment.These data are representative of low to moderate wind regimes.The aerodynamic roughness length is determined by using the Charnock relationship.The intercomparison shows that the Louis scheme and the COARE algorithm underestimate the friction velocity by 6% and 3% respectively under pure wind sea conditions,15% and 13% respectively under cross swell conditions,and 21% and 17% respectively under counter swell conditions.The analysis shows that these underestimations were caused by the method chosen to determine the aerodynamic roughness length because it significantly underestimates the aerodynamic roughness length.It is especially true under the cross swell and counter swell conditions.
The Louis scheme and the COARE algorithm(version 3.0) are tested against eddy covariance and inertial dissipation methods for friction velocity estimates in different wind-sea/swell regimes.Atmospheric forcing data,tabulated by Donelan et al.(1997.J Phys Oceanog,27:2 087~2 099),were collected from a mast on the foredeck ofa SWATH(small water-plane area,twin hull) ship in deep sea off the State of Virginia during the surface wave dynamics experiment.These data are representative of low to moderate wind regimes.The aerodynamic roughness length is determined by using the Charnock relationship.The intercomparison shows that the Louis scheme and the COARE algorithm underestimate the friction velocity by 6% and 3% respectively under pure wind sea conditions,15% and 13% respectively under cross swell conditions,and 21% and 17% respectively under counter swell conditions.The analysis shows that these underestimations were caused by the method chosen to determine the aerodynamic roughness length because it significantly underestimates the aerodynamic roughness length.It is especially true under the cross swell and counter swell conditions.
2005, (4): 29-42.
Abstract:
Wind speed scaling in similarity law in wind-generated waves and the drag coefficient are studied.In analyzing the data in the wind wave channel,it is found that the u* scaling greatly reduces the scatter in the U10 scaling.The u* scaling has much less scatter than the scaling using other wind speeds.The friction velocity seems to play a distinctive role in wave growth.The result is important in the applications of the similarity law and in wave modeling.In theory it gives an insight into the mechanism of wind wave interaction.It is found that wave steepness is important in influencing the drag coefficient.The variability of the coefficients in the currently widely used drag form can be explained by the differences in wave steepness in the observations.A drag coefficient model with wind speed and wave steepness as parameters is proposed.An explanation for Kahma's result that the u* scaling does not reduce the scatter in the U10 scaling is given.
Wind speed scaling in similarity law in wind-generated waves and the drag coefficient are studied.In analyzing the data in the wind wave channel,it is found that the u* scaling greatly reduces the scatter in the U10 scaling.The u* scaling has much less scatter than the scaling using other wind speeds.The friction velocity seems to play a distinctive role in wave growth.The result is important in the applications of the similarity law and in wave modeling.In theory it gives an insight into the mechanism of wind wave interaction.It is found that wave steepness is important in influencing the drag coefficient.The variability of the coefficients in the currently widely used drag form can be explained by the differences in wave steepness in the observations.A drag coefficient model with wind speed and wave steepness as parameters is proposed.An explanation for Kahma's result that the u* scaling does not reduce the scatter in the U10 scaling is given.
2005, (4): 43-53.
Abstract:
To study how the air and sea interact with each other during El Niño/La Ninña onsets,extended associate pattern analysis(EAPA) is adopted with the simple ocean data assimilation(SODA) data.The results show that as El Niño/La Ninña's parents their behaviors are quite different,there does not exist a relatively independent tropical atmosphere but does exist a relatively independent tropical Pacific Ocean because the air is heated from the bottom surface instead of the top surface and of much stronger baroclinic instability than the sea and has a very large inter-tropical convergence zone covering the most tropical Pacific Ocean.The idea that it is the wester burst and wind convergence,coming from middle latitudes directly that produce the seawater eastward movement and meridional convergence in the upper levels and result in the typical El Niño sea surface temperature warm signal is confirmed again.
To study how the air and sea interact with each other during El Niño/La Ninña onsets,extended associate pattern analysis(EAPA) is adopted with the simple ocean data assimilation(SODA) data.The results show that as El Niño/La Ninña's parents their behaviors are quite different,there does not exist a relatively independent tropical atmosphere but does exist a relatively independent tropical Pacific Ocean because the air is heated from the bottom surface instead of the top surface and of much stronger baroclinic instability than the sea and has a very large inter-tropical convergence zone covering the most tropical Pacific Ocean.The idea that it is the wester burst and wind convergence,coming from middle latitudes directly that produce the seawater eastward movement and meridional convergence in the upper levels and result in the typical El Niño sea surface temperature warm signal is confirmed again.
2005, (4): 54-65.
Abstract:
A new viscoelastic-plastic(VEP) constitutive model for sea ice dynamics was developed based on continuum mechanics.This model consists of four components:Kelvin-Vogit viscoelastic model,Mohr-Coulomb yielding criterion,associated normality flow rule for plastic rehololgy,and hydrostatic pressure.The numerical simulations for ice motion in an idealized rectangular basin were made using smoothed particle hydrodynamics(SPH) method,and compared with the analytical solution as well as those based on the modified viscous plastic(VP) model and static ice jam theory.These simulations show that the new VEP modelcan simulate ice dynamics accurately.The new constitutive model was further applied to simulate ice dynamics of the Bohai Sea and compared with the traditional VP,and modified VP models.The results of the VEP model are compared better with the satellite remote images,and the simulated ice conditions in the JZ20-2 oil platform area were more reasonable.
A new viscoelastic-plastic(VEP) constitutive model for sea ice dynamics was developed based on continuum mechanics.This model consists of four components:Kelvin-Vogit viscoelastic model,Mohr-Coulomb yielding criterion,associated normality flow rule for plastic rehololgy,and hydrostatic pressure.The numerical simulations for ice motion in an idealized rectangular basin were made using smoothed particle hydrodynamics(SPH) method,and compared with the analytical solution as well as those based on the modified viscous plastic(VP) model and static ice jam theory.These simulations show that the new VEP modelcan simulate ice dynamics accurately.The new constitutive model was further applied to simulate ice dynamics of the Bohai Sea and compared with the traditional VP,and modified VP models.The results of the VEP model are compared better with the satellite remote images,and the simulated ice conditions in the JZ20-2 oil platform area were more reasonable.
2005, (4): 66-71.
Abstract:
The construction of oceanographic ontologies is fundamental to the "digital ocean".Therefore,on the basis of introduction of new concept of oceanographic ontology,an oceanographic ontology-based spatial knowledge query(OOBSKQ) method was proposed and developed.Because the method uses a natural language to describe query conditions and the query result is highly integrated knowledge,it can provide users with direct answers while hiding the complicated computation and reasoning processes,and achieves intelligent,automatic oceanographic spatial information query on the level of knowledge and semantics.A case study of resource and environmental application in bay has shown the implementation process of the method and its feasibility and usefulness.
The construction of oceanographic ontologies is fundamental to the "digital ocean".Therefore,on the basis of introduction of new concept of oceanographic ontology,an oceanographic ontology-based spatial knowledge query(OOBSKQ) method was proposed and developed.Because the method uses a natural language to describe query conditions and the query result is highly integrated knowledge,it can provide users with direct answers while hiding the complicated computation and reasoning processes,and achieves intelligent,automatic oceanographic spatial information query on the level of knowledge and semantics.A case study of resource and environmental application in bay has shown the implementation process of the method and its feasibility and usefulness.
2005, (4): 72-80.
Abstract:
The contents of total copper,total dissolved copper,particulate copper,and free ion copper in the Zhujiang River Estuary were investigated in July 2002 and January 2003 respectively,and the spatial distribution trend of these species of copper were compared in two cruises.It was found that,in summer,the total copper content in the Zhujiang River Estuary increased with salinity,while the content of free ion copper decreased with salinity.However,in winter,the contents of total copper and free ion copper both decreased with salinity.So,it could be concluded that,copper content and speciation in the Zhujiang River Estuary were regulated by other factors than runoffdiffusion such as upwelling current.In order to prove the spatial trend of free ion copper content in the Zhujiang River Estuary,the cultivation of Dunaliella tertiolecta in waters obtained from sampling stations with different salinities was carried out,and the copper uptake by algae cells was measured then.It was found that,the cells' uptake of copper increased with free ion copper,not the content of total copper.
The contents of total copper,total dissolved copper,particulate copper,and free ion copper in the Zhujiang River Estuary were investigated in July 2002 and January 2003 respectively,and the spatial distribution trend of these species of copper were compared in two cruises.It was found that,in summer,the total copper content in the Zhujiang River Estuary increased with salinity,while the content of free ion copper decreased with salinity.However,in winter,the contents of total copper and free ion copper both decreased with salinity.So,it could be concluded that,copper content and speciation in the Zhujiang River Estuary were regulated by other factors than runoffdiffusion such as upwelling current.In order to prove the spatial trend of free ion copper content in the Zhujiang River Estuary,the cultivation of Dunaliella tertiolecta in waters obtained from sampling stations with different salinities was carried out,and the copper uptake by algae cells was measured then.It was found that,the cells' uptake of copper increased with free ion copper,not the content of total copper.
2005, (4): 81-90.
Abstract:
Calibrations between sodium(Na+) concentrations from a Mt.Logan ice core and sea level pressure(SLP) series show that Na+ concentrations are closely correlated with the autumn-time(SeptemberOctober-November) Aleutian low(AleuLow).A deepening of the AleuLow strengthens the transport of sea-salt aerosols from the North Pacific to the Mt.Logan region.The Mt.Logan Na+ record is used to develop a 292 a(1688~1979) reconstruction of the AleuLow revealing a dramatic intensification of atmospheric circulation over the North Pacific region since the 20th century.Mean SLP of the AleuLow was about 1 hPa lower during the 20th century than during prior periods.The strongest deepening of the AleuLow appeared in the 1950s.Significant correlations are also found between the Mt.Logan AleuLow proxy series and the Pacific decadal oscillation(PDO) and Pacific circulation(PC) index during the 20th century.Evolutionary spectral analysis of the proxy record shows significant periodicities from 15 to 30 a consistent with PDO fluctuations and the bidecadal oscillation of North Pacific atmosphere-ocean circulation.A period of 11 a in the AleuLow record may be associated with the Schwabe 11-a cycle of sunspot activity.Additional longer ice core records from this region will aid in the efforts to further understand the climatic change over the North Pacific region.
Calibrations between sodium(Na+) concentrations from a Mt.Logan ice core and sea level pressure(SLP) series show that Na+ concentrations are closely correlated with the autumn-time(SeptemberOctober-November) Aleutian low(AleuLow).A deepening of the AleuLow strengthens the transport of sea-salt aerosols from the North Pacific to the Mt.Logan region.The Mt.Logan Na+ record is used to develop a 292 a(1688~1979) reconstruction of the AleuLow revealing a dramatic intensification of atmospheric circulation over the North Pacific region since the 20th century.Mean SLP of the AleuLow was about 1 hPa lower during the 20th century than during prior periods.The strongest deepening of the AleuLow appeared in the 1950s.Significant correlations are also found between the Mt.Logan AleuLow proxy series and the Pacific decadal oscillation(PDO) and Pacific circulation(PC) index during the 20th century.Evolutionary spectral analysis of the proxy record shows significant periodicities from 15 to 30 a consistent with PDO fluctuations and the bidecadal oscillation of North Pacific atmosphere-ocean circulation.A period of 11 a in the AleuLow record may be associated with the Schwabe 11-a cycle of sunspot activity.Additional longer ice core records from this region will aid in the efforts to further understand the climatic change over the North Pacific region.
2005, (4): 91-97.
Abstract:
One new species of free-living marine nematode of the genus Curvolaimus,Curvolaimus filiformis sp.nov.from the Huanghai Sea is described and illustrated.This new species is characterized by the buccal cavity teeth,large amphids and two ventral seta at the conical part of tail.Meanwhile,two new records of genus Halalaimus,Halalaimus longic audatus and H.isaitshikovi are first reported in China.Types are deposited in the College of Marine Life Sciences,Ocean University of China.
One new species of free-living marine nematode of the genus Curvolaimus,Curvolaimus filiformis sp.nov.from the Huanghai Sea is described and illustrated.This new species is characterized by the buccal cavity teeth,large amphids and two ventral seta at the conical part of tail.Meanwhile,two new records of genus Halalaimus,Halalaimus longic audatus and H.isaitshikovi are first reported in China.Types are deposited in the College of Marine Life Sciences,Ocean University of China.
2005, (4): 98-106.
Abstract:
Based on the data of four seasonal oceanographic censuses in the East China Sea(23°30'~33°00'N,118°30'~128°00'E) in 1997~2000,the species composition and the diversity of Euphausiacea were discussed as well as their relations with environmental variables.Results showed that there were totally 23 different species of Euphausiacea,in which 16 occurred in spring and autumn respectively; 15 were present in summer and only 10 were observed in winter.According to the calculated alternation fraction(R),the species composition showed a clear seasonal alternation with the changes ofseasons.Moreover,the environmental variables had different impacts on the distribution of Euphausiacea in different seasons.The distribution in summer was not significantly related to water temperature and salinity.However,the surface salinity was a major determinant of the distribution in spring.In autumn,both surface and bottom temperatures were influencing factors.The distribution in winter depended on salinity at the surface and 10 m depth as well as the temperature at 10 m depth.Regarding to the seasonal variation of species composition,the variations in spring,summer and autumn were not so significant as those in winter.Except in summer,the species number changed with synchronous water temperature and salinity,as a result of the presence of warm currents in the East China Sea and the habitability of the dominant species.Since Euphausiacea tend to agglomerate,the distribution of different species was uneven,which was the major reason for the low diversity of Euphausiacea in the East China Sea.
Based on the data of four seasonal oceanographic censuses in the East China Sea(23°30'~33°00'N,118°30'~128°00'E) in 1997~2000,the species composition and the diversity of Euphausiacea were discussed as well as their relations with environmental variables.Results showed that there were totally 23 different species of Euphausiacea,in which 16 occurred in spring and autumn respectively; 15 were present in summer and only 10 were observed in winter.According to the calculated alternation fraction(R),the species composition showed a clear seasonal alternation with the changes ofseasons.Moreover,the environmental variables had different impacts on the distribution of Euphausiacea in different seasons.The distribution in summer was not significantly related to water temperature and salinity.However,the surface salinity was a major determinant of the distribution in spring.In autumn,both surface and bottom temperatures were influencing factors.The distribution in winter depended on salinity at the surface and 10 m depth as well as the temperature at 10 m depth.Regarding to the seasonal variation of species composition,the variations in spring,summer and autumn were not so significant as those in winter.Except in summer,the species number changed with synchronous water temperature and salinity,as a result of the presence of warm currents in the East China Sea and the habitability of the dominant species.Since Euphausiacea tend to agglomerate,the distribution of different species was uneven,which was the major reason for the low diversity of Euphausiacea in the East China Sea.
2005, (4): 107-113.
Abstract:
The AFLP(amplified fragment length polymorphism)technique was used to analyse the genetic diversity in four scallop species,Patinopecten yessoensis,Argopecten irradians,Chlamys nobilis and C.farreri.The genetic similarity indexes of these four species are 0.841 5,0.786 3,0.719 0 and 0.673 1,while Shannon diversity indexes are 43.52,58.87,80.16 and 92.83,respectively.As analyzed,the genetic diversities in two native species,i.e.,C.farreri and C.nobilis,are higher than those in other two introduced species,A.irradians and P.yessoensis.The results also showed that C.nobilis and C.farreri shared the most common loci.The genetic distance indicated that C.nobilis and C.farreri are closely related.Moreover,out of 510 AFLP markers,21 specific bands are found to distinguish the four species scallops and these markers may be applied to the specific germplasm characterization and molecular assistant classification in scallops.
The AFLP(amplified fragment length polymorphism)technique was used to analyse the genetic diversity in four scallop species,Patinopecten yessoensis,Argopecten irradians,Chlamys nobilis and C.farreri.The genetic similarity indexes of these four species are 0.841 5,0.786 3,0.719 0 and 0.673 1,while Shannon diversity indexes are 43.52,58.87,80.16 and 92.83,respectively.As analyzed,the genetic diversities in two native species,i.e.,C.farreri and C.nobilis,are higher than those in other two introduced species,A.irradians and P.yessoensis.The results also showed that C.nobilis and C.farreri shared the most common loci.The genetic distance indicated that C.nobilis and C.farreri are closely related.Moreover,out of 510 AFLP markers,21 specific bands are found to distinguish the four species scallops and these markers may be applied to the specific germplasm characterization and molecular assistant classification in scallops.
2005, (4): 114-120.
Abstract:
In 2002,six cohorts ofbroodstock bay scallop Argopecten irradians irradians(Ne=l,2,10,30,50 and control) were randomly chosen from a population of bay scallop to produce offspring.After one year rearing,with the progeny matured,the similar experiment was done to produce the F2 generation.To determine the magnitude of Ne effects,the growth and survival rates in larvae and adult of six F2 groups were compared.Results showed that inbreeding depression existed not only in the Ne=1 group but also in the Ne=2 group.The growth and survival rates of the two groups were significantly lower than those of the other groups(Ne=10,30,50,control),and there were no significant differences among the latter(P>0.05).At the same time,the amount of depression in the Ne=l group was significantly higher than that of the Ne=2 group(P<0.05).These results indicated that the low effective population size(Ne),which increases the possibility of inbreeding,could lead to some harmful effects on the offspring.So it is essential to maintain a high level of Ne in commercial seed production.Furthermore,as the high fecundity of bay scallop might lead to increased inbreeding,selecting broodstock from different growout sites is recommended.
In 2002,six cohorts ofbroodstock bay scallop Argopecten irradians irradians(Ne=l,2,10,30,50 and control) were randomly chosen from a population of bay scallop to produce offspring.After one year rearing,with the progeny matured,the similar experiment was done to produce the F2 generation.To determine the magnitude of Ne effects,the growth and survival rates in larvae and adult of six F2 groups were compared.Results showed that inbreeding depression existed not only in the Ne=1 group but also in the Ne=2 group.The growth and survival rates of the two groups were significantly lower than those of the other groups(Ne=10,30,50,control),and there were no significant differences among the latter(P>0.05).At the same time,the amount of depression in the Ne=l group was significantly higher than that of the Ne=2 group(P<0.05).These results indicated that the low effective population size(Ne),which increases the possibility of inbreeding,could lead to some harmful effects on the offspring.So it is essential to maintain a high level of Ne in commercial seed production.Furthermore,as the high fecundity of bay scallop might lead to increased inbreeding,selecting broodstock from different growout sites is recommended.
2005, (4): 121-130.
Abstract:
Wave forces induced by the interaction between the oblique incident wave and the breakwater with a partially perforated front wall is investigated.The fluid domain is divided into two sub-domains and the eigen-function expansion method is applied to expanding velocity potentials in each domain.In the eigen-expansion of the velocity potential,evanescent waves are included.Numerical results of the present model are compared with other theories and a good agreement can be found between them.Experimental data have been compared with the present theoretical results.The effect of the traverse wall on wave forces has been discussed in detail.On the basis of the linear wave theory,it is shown that in the range of engineering practice,the incident angle of wave has small influence on wave forces on the unit length of perforated caisson.
Wave forces induced by the interaction between the oblique incident wave and the breakwater with a partially perforated front wall is investigated.The fluid domain is divided into two sub-domains and the eigen-function expansion method is applied to expanding velocity potentials in each domain.In the eigen-expansion of the velocity potential,evanescent waves are included.Numerical results of the present model are compared with other theories and a good agreement can be found between them.Experimental data have been compared with the present theoretical results.The effect of the traverse wall on wave forces has been discussed in detail.On the basis of the linear wave theory,it is shown that in the range of engineering practice,the incident angle of wave has small influence on wave forces on the unit length of perforated caisson.
2005, (4): 131-137.
Abstract:
Boussinesq-type equations and mild-slope equations are compared in terms of their basic forms and characteristics.It is concluded that linear mild-slope equations on dispersion relation are better than non-linear Boussinesq equations.In addition,Berkhoff experiments are computed and compared by the two models,and agreement between model results and available experimental data is found to be quite reasonable,which demonstrates the two models' capacity to simulate wave transformation.However they can deal with different physical processes respectively,and they have their own characteristics.
Boussinesq-type equations and mild-slope equations are compared in terms of their basic forms and characteristics.It is concluded that linear mild-slope equations on dispersion relation are better than non-linear Boussinesq equations.In addition,Berkhoff experiments are computed and compared by the two models,and agreement between model results and available experimental data is found to be quite reasonable,which demonstrates the two models' capacity to simulate wave transformation.However they can deal with different physical processes respectively,and they have their own characteristics.
2005, (4): 138-145.
Abstract:
Cyclic triaxial tests and numerical analyses were undertaken,in order to evaluate the wave-induced pore water pressure in seabed sediments in the Hangzhou Bay.The cyclic triaxial tests indicate that the rate of pore water pressure generation in cohesive soils decreases with time,and the development of the pore water pressure can be represented by a hyperbolic curve.Numerical analyses,taking into account the generation and dissipation of pore water pressure simultaneously,suggest that the pore water pressure buildup in cohesive soils may increase with time continuously until the pore water pressure ratio approaches to 1,or it may decrease after a certain time,which is controlled by drain conditions.These phenomena are different from those in sands.For waves with a return period of 100 a in the Hangzhou Bay,ifthe wave duration is more than 60 h,then the pore water pressure ratio will be close to 1 and soil fabric failure will take place.
Cyclic triaxial tests and numerical analyses were undertaken,in order to evaluate the wave-induced pore water pressure in seabed sediments in the Hangzhou Bay.The cyclic triaxial tests indicate that the rate of pore water pressure generation in cohesive soils decreases with time,and the development of the pore water pressure can be represented by a hyperbolic curve.Numerical analyses,taking into account the generation and dissipation of pore water pressure simultaneously,suggest that the pore water pressure buildup in cohesive soils may increase with time continuously until the pore water pressure ratio approaches to 1,or it may decrease after a certain time,which is controlled by drain conditions.These phenomena are different from those in sands.For waves with a return period of 100 a in the Hangzhou Bay,ifthe wave duration is more than 60 h,then the pore water pressure ratio will be close to 1 and soil fabric failure will take place.
2005, (4): 146-154.
Abstract:
On the basis of accelerator mass spectrometer radiocarbon(AMS 14C) dating,sedimentation rates of 11 cores collected from the northern to southern Okinawa Trough are discussed.The sedimentation rates in the Okinawa Trough roughly range from 11 to 39 cm/ka,and the average is 23.0 cm/ka.China's continental matter is the main sediment source of the middle Okinawa Trough and has important contribution to the northern and southern Okinawa Trough.The sedimentation rates during the marine oxygen isotope(MIS)2 are uniformly higher than those during MIS 1 in the northern and middle Okinawa Trough while they are on the contrary in the southern Okinawa Trough.Sedimentation rates in the Okinawa Trough can be one of the proxies of sediment source and an indicator of cooling events.
On the basis of accelerator mass spectrometer radiocarbon(AMS 14C) dating,sedimentation rates of 11 cores collected from the northern to southern Okinawa Trough are discussed.The sedimentation rates in the Okinawa Trough roughly range from 11 to 39 cm/ka,and the average is 23.0 cm/ka.China's continental matter is the main sediment source of the middle Okinawa Trough and has important contribution to the northern and southern Okinawa Trough.The sedimentation rates during the marine oxygen isotope(MIS)2 are uniformly higher than those during MIS 1 in the northern and middle Okinawa Trough while they are on the contrary in the southern Okinawa Trough.Sedimentation rates in the Okinawa Trough can be one of the proxies of sediment source and an indicator of cooling events.
2005, (4): 155-161.
Abstract:
Dot enzyme-linked immunosorbent assay(dot-ELISA),indirect ELISA and Western blot were performed to detect the virulent protease secreted by Vibrio anguillarum which was isolated from the diseased left-eyed flounder,Paralichthys olivaceous.Sensitivity results showed that dot-ELISA is a more sensitive,rapid and simple technique for the protease detection.The minimal detectable amount of protease is about 7 pg in the dot-ELISA test,while 7.8 ng in the indirect ELISA and 6.25 ng in the Western blot respectively.Protease could be detected 2 h after incubation of V.anguillarum in the 2216E liquid medium but enzyme activity was very low at that period.From 6 to 12 h,the amount and enzyme activity ofprotease increased markedly and reached maximum at stationary phase.Analysis of serum samples periodically collected from the infected flounders showed that after 2 h of infection by V.anguillarum,the pathogenic bacteria could be detected in the blood of the infected flounders but no protease was found.It was 5~6 h after infection that the protease was detected in blood and then the amount increased as infection advanced.Quantitative detection of protease either incubation in the medium or from the blood of infected flounders could be accomplished in virtue of positive controls of quantificational protease standards("marker") so that the alterations of protease secretion both in vitro and in vivo could be understood generally.In addition,the indirect ELISA and dot-ELISA were also performed to detect V.anguillarum cells.Results indicated that the sensitivity of indirect ELISA to bacteria cells is higher than that of the dot-ELISA,and that the minimal detectable amount is approximately 104 cell/mL in the indirect ELISA,while 105 cell/mL in the dot-ELISA.
Dot enzyme-linked immunosorbent assay(dot-ELISA),indirect ELISA and Western blot were performed to detect the virulent protease secreted by Vibrio anguillarum which was isolated from the diseased left-eyed flounder,Paralichthys olivaceous.Sensitivity results showed that dot-ELISA is a more sensitive,rapid and simple technique for the protease detection.The minimal detectable amount of protease is about 7 pg in the dot-ELISA test,while 7.8 ng in the indirect ELISA and 6.25 ng in the Western blot respectively.Protease could be detected 2 h after incubation of V.anguillarum in the 2216E liquid medium but enzyme activity was very low at that period.From 6 to 12 h,the amount and enzyme activity ofprotease increased markedly and reached maximum at stationary phase.Analysis of serum samples periodically collected from the infected flounders showed that after 2 h of infection by V.anguillarum,the pathogenic bacteria could be detected in the blood of the infected flounders but no protease was found.It was 5~6 h after infection that the protease was detected in blood and then the amount increased as infection advanced.Quantitative detection of protease either incubation in the medium or from the blood of infected flounders could be accomplished in virtue of positive controls of quantificational protease standards("marker") so that the alterations of protease secretion both in vitro and in vivo could be understood generally.In addition,the indirect ELISA and dot-ELISA were also performed to detect V.anguillarum cells.Results indicated that the sensitivity of indirect ELISA to bacteria cells is higher than that of the dot-ELISA,and that the minimal detectable amount is approximately 104 cell/mL in the indirect ELISA,while 105 cell/mL in the dot-ELISA.
