2004 Vol. 23, No. 4
Display Method:
2004, (4): 569-579.
Abstract:
Using the National Center for Enviromental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis data and NOAA satellite-observed outgoing long-wave radiation (OLR) data,the development of the South China Sea (SCS) summer monsoon and intraseasonal (30~60 d) oscillation (ISO) have been examined.The results show that there exists obvious interannual variability of intraseasonal oscillaiton.Using the 16 a time series of filtered OLR averaged over the SCS,an index is defined to define "onset events" over the SCS on the ISO time scales.Of the 16 a examined here,10 shows a strong ISO signal in the onset of monsoon convection over the SCS.In these cases,the ISO initially suppresses the seasonal development of southwesterly and cyclonic circulation over the SCS before the ISO onset.As the ISO propagates northeastward,the low frequency cyclonic circulation anomaly occurs in the SCS and the low frequency southwesterly wind and convection over here dramatically intensify.The northeast progression of the ISO anomaleis plays a role in the initial suppression and then acceleration of the seasonal cycle of the SCS summer monsoon.
Using the National Center for Enviromental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis data and NOAA satellite-observed outgoing long-wave radiation (OLR) data,the development of the South China Sea (SCS) summer monsoon and intraseasonal (30~60 d) oscillation (ISO) have been examined.The results show that there exists obvious interannual variability of intraseasonal oscillaiton.Using the 16 a time series of filtered OLR averaged over the SCS,an index is defined to define "onset events" over the SCS on the ISO time scales.Of the 16 a examined here,10 shows a strong ISO signal in the onset of monsoon convection over the SCS.In these cases,the ISO initially suppresses the seasonal development of southwesterly and cyclonic circulation over the SCS before the ISO onset.As the ISO propagates northeastward,the low frequency cyclonic circulation anomaly occurs in the SCS and the low frequency southwesterly wind and convection over here dramatically intensify.The northeast progression of the ISO anomaleis plays a role in the initial suppression and then acceleration of the seasonal cycle of the SCS summer monsoon.
2004, (4): 581-595.
Abstract:
The simulated ENSO and Indian Ocean dipole (IOD) mode events from three coupled GCMs with the same oceanic component model,CPM0,CPM1 and FGCM0,are compared.The only difference between the CPM0 and the CPM1 comes from the coupling scheme at the air-sea interface,e.g.,flux anomaly coupling scheme for the former and direct coupling scheme for the latter.The FGCM0 is also a directly coupled GCM,but its atmospheric component model is the NCAR CCM3 rather than the NCC T63AGCM as in the other two coupled GCMs CPM0 and CPM1.All three coupled models show El Niño-like interannual variability in the tropic Pacific,but the FGCM0 shows a bit stronger amplitude of El Niño events and both the CPM0 and the CPM1 show much weaker amplitude than the observed one.In the meanwhile,the quasi-biennial variability dominates in the FGCM0 simulations,and 4 a and longer periods are significant in both the CPM0 and CPM1 models.As the El Niño events simulated by the three coupled GCMs,the simulated Indian Ocean dipole mode events are stronger from the coupled model FGCM0 and weaker from both the CPM0 and CPM1 models than those from observation.
The simulated ENSO and Indian Ocean dipole (IOD) mode events from three coupled GCMs with the same oceanic component model,CPM0,CPM1 and FGCM0,are compared.The only difference between the CPM0 and the CPM1 comes from the coupling scheme at the air-sea interface,e.g.,flux anomaly coupling scheme for the former and direct coupling scheme for the latter.The FGCM0 is also a directly coupled GCM,but its atmospheric component model is the NCAR CCM3 rather than the NCC T63AGCM as in the other two coupled GCMs CPM0 and CPM1.All three coupled models show El Niño-like interannual variability in the tropic Pacific,but the FGCM0 shows a bit stronger amplitude of El Niño events and both the CPM0 and the CPM1 show much weaker amplitude than the observed one.In the meanwhile,the quasi-biennial variability dominates in the FGCM0 simulations,and 4 a and longer periods are significant in both the CPM0 and CPM1 models.As the El Niño events simulated by the three coupled GCMs,the simulated Indian Ocean dipole mode events are stronger from the coupled model FGCM0 and weaker from both the CPM0 and CPM1 models than those from observation.
2004, (4): 597-608.
Abstract:
According to the earlier international studies on the coupled ice-ocean model and the hydrology,meteorology,and ice features in the Bohai Sea,a coupled ice-ocean model is developed based on the National Marine Environment Forecast Center's (NMEFC) numerical forecasting ice model of the Bohai Sea and the Princeton ocean model (POM).In the coupled model,the transfer of momentum and heat between ocean and ice is two-way,and the change of ice thickness and concentration depends on heat budget not only at the surface and bottom of ice,but also at the surface of open water between ices.The dynamic and thermodynamic coupling process is expatiated emphatically.Some thermodynamic parameters are discussed as well.
According to the earlier international studies on the coupled ice-ocean model and the hydrology,meteorology,and ice features in the Bohai Sea,a coupled ice-ocean model is developed based on the National Marine Environment Forecast Center's (NMEFC) numerical forecasting ice model of the Bohai Sea and the Princeton ocean model (POM).In the coupled model,the transfer of momentum and heat between ocean and ice is two-way,and the change of ice thickness and concentration depends on heat budget not only at the surface and bottom of ice,but also at the surface of open water between ices.The dynamic and thermodynamic coupling process is expatiated emphatically.Some thermodynamic parameters are discussed as well.
2004, (4): 609-615.
Abstract:
A practical algorithm of atmospheric correction for turbid coastal and inland waters is provided.The present algorithm uses the property that the water-leaving radiance at 412 nm increases very little with the increasing of water turbidity.Thus,in very turbid coastal and inland waters,the radiance at 412 nm can be used to estimate the aerosol scattering radiance at 865 nm.The performance of the new algorithm is validated with simulation for several cases.It is found that the retrieved remotely sensed reflectance is usually with error less than 10% for the first six bands of SeaWiFS.This new algorithm is also tested under various atmospheric conditions in the Changjiang River Estuary and the Hangzhou Bay where the sediment concentration is very high and the standard SeaWiFS atmospheric correction algorithm creates a mask due to atmospheric correction failure.The result proves the efficiency of this simple algorithm in reducing the errors of the water-leaving radiance retrieving using SeaWiFS satellite data.
A practical algorithm of atmospheric correction for turbid coastal and inland waters is provided.The present algorithm uses the property that the water-leaving radiance at 412 nm increases very little with the increasing of water turbidity.Thus,in very turbid coastal and inland waters,the radiance at 412 nm can be used to estimate the aerosol scattering radiance at 865 nm.The performance of the new algorithm is validated with simulation for several cases.It is found that the retrieved remotely sensed reflectance is usually with error less than 10% for the first six bands of SeaWiFS.This new algorithm is also tested under various atmospheric conditions in the Changjiang River Estuary and the Hangzhou Bay where the sediment concentration is very high and the standard SeaWiFS atmospheric correction algorithm creates a mask due to atmospheric correction failure.The result proves the efficiency of this simple algorithm in reducing the errors of the water-leaving radiance retrieving using SeaWiFS satellite data.
The statistic inversion algorithms of water constituents for the Huanghai Sea and the East China Sea
2004, (4): 617-626.
Abstract:
A group of statistical algorithms are proposed for the inversion of the three major components of Case-Ⅱ waters in the coastal area of the Huanghai Sea and the East China Sea.The algorithms are based on the in situ data collected in the spring of 2003 with strict quality assurance according to NASA ocean bio-optic protocols.These algorithms are the first ones with quantitative confidence that can be applied for the area.The average relative error of the inversed and in situ measured components' concentrations are:Chl-a about 37%,total suspended matter (TSM) about 25%,respectively.This preliminary result is quite satisfactory for Case-Ⅱ waters,although some aspects in the model need further study.The sensitivity of the input error of 5% to remote sensing reflectance (Rrs) is also analyzed and it shows the algorithms are quite stable.The algorithms show a large difference with Tassan's local SeaWiFS algorithms for different waters,except for the Chl-a algorithm.
A group of statistical algorithms are proposed for the inversion of the three major components of Case-Ⅱ waters in the coastal area of the Huanghai Sea and the East China Sea.The algorithms are based on the in situ data collected in the spring of 2003 with strict quality assurance according to NASA ocean bio-optic protocols.These algorithms are the first ones with quantitative confidence that can be applied for the area.The average relative error of the inversed and in situ measured components' concentrations are:Chl-a about 37%,total suspended matter (TSM) about 25%,respectively.This preliminary result is quite satisfactory for Case-Ⅱ waters,although some aspects in the model need further study.The sensitivity of the input error of 5% to remote sensing reflectance (Rrs) is also analyzed and it shows the algorithms are quite stable.The algorithms show a large difference with Tassan's local SeaWiFS algorithms for different waters,except for the Chl-a algorithm.
2004, (4): 627-635.
Abstract:
A series of test simulations are performed to evaluate the impact of satellite-derived meteorological data on numerical typhoon track prediction.Geostationary meteorological satellite (GMS-5) and NOAA's TIROS operational vertical sounder (TOVS) observations are used in the experiments.A three-dimensional variational (3D-Var) assimilation scheme is developed to assimilate the satellite data directly into the Penn State-NCAR nonhydrostatic meteorological model (MM5).Three-dimensional objective analysis fields based on the T213 results and conventional observations are employed as the background fields of the initialization.The comparisons of the simulated typhoon tracks are carried out,which correspond respectively to assimilate different kinds of satellite data.It is found that,compared with the experiment without satellite data assimilation,the 3D-Var assimilation schemes lead to significant improvements on typhoon track prediction.Track errors reduce from approximately 25% at 24 h to approximately 30% at 48 h for 3D-Var assimilation experiments.
A series of test simulations are performed to evaluate the impact of satellite-derived meteorological data on numerical typhoon track prediction.Geostationary meteorological satellite (GMS-5) and NOAA's TIROS operational vertical sounder (TOVS) observations are used in the experiments.A three-dimensional variational (3D-Var) assimilation scheme is developed to assimilate the satellite data directly into the Penn State-NCAR nonhydrostatic meteorological model (MM5).Three-dimensional objective analysis fields based on the T213 results and conventional observations are employed as the background fields of the initialization.The comparisons of the simulated typhoon tracks are carried out,which correspond respectively to assimilate different kinds of satellite data.It is found that,compared with the experiment without satellite data assimilation,the 3D-Var assimilation schemes lead to significant improvements on typhoon track prediction.Track errors reduce from approximately 25% at 24 h to approximately 30% at 48 h for 3D-Var assimilation experiments.
2004, (4): 637-645.
Abstract:
Several methods for analysis of dissolved total phosphorus in seawater were reviewed.Discussions were focused on UV irradiation and persulphate oxidation methods which are the most popular dissolved organic phosphorus determination methods presently.The compounds used for the phosphorus recovery test were categorized into three groups according to their chemical structure.It was found that low power UV irradiation can decompose P-O-C or P-C bonds efficiently but may be inefficient for P-O-P bonds.Heating-bath in acid condition is useful for decomposing P-O-P bonds.Using the continuous flow analysis system (Auto-analyzer Ⅱ),UV digestion and heating-bath,series experiments were carried out based on the above analysis.Eleven model compounds were employed for the phosphorus recovery test and the factors influencing the decomposition efficiency of dissolved compounds containing phosphorus were clarified.Finally,the optimal design for determination of dissolved total phosphorus in seawater based on the routine continuous flow analysis system was presented.For the organic mono-phosphate,the recovery is more than 90% and a recovery of 33%~51% was obtained for inorganic or organic polyphosphates.Up to now,this is the highest decomposition efficiency for dissolved phosphorus based on the continuous flow analysis system.
Several methods for analysis of dissolved total phosphorus in seawater were reviewed.Discussions were focused on UV irradiation and persulphate oxidation methods which are the most popular dissolved organic phosphorus determination methods presently.The compounds used for the phosphorus recovery test were categorized into three groups according to their chemical structure.It was found that low power UV irradiation can decompose P-O-C or P-C bonds efficiently but may be inefficient for P-O-P bonds.Heating-bath in acid condition is useful for decomposing P-O-P bonds.Using the continuous flow analysis system (Auto-analyzer Ⅱ),UV digestion and heating-bath,series experiments were carried out based on the above analysis.Eleven model compounds were employed for the phosphorus recovery test and the factors influencing the decomposition efficiency of dissolved compounds containing phosphorus were clarified.Finally,the optimal design for determination of dissolved total phosphorus in seawater based on the routine continuous flow analysis system was presented.For the organic mono-phosphate,the recovery is more than 90% and a recovery of 33%~51% was obtained for inorganic or organic polyphosphates.Up to now,this is the highest decomposition efficiency for dissolved phosphorus based on the continuous flow analysis system.
2004, (4): 647-653.
Abstract:
The data were collected during Chinese Arctic and Antarctic Expeditions in the western Arctic Ocean and the marginal sea ice zone (MSIZ) of the Southern Ocean,respectively in the boreal summer from July to September of 1999 and in the austral summer from December of 1999 to January of 2000.The concentrations of CO2 in surface water of the survey regions would mostly present lower than those in the atmosphere.A significant biological driving force could also been observed in summer waters in both of the above oceans.Air to sea CO2 fluxes were also calculated to compare oceanic uptake capacity of CO2 in both oceans with the world oceans using Liss,Wanninkhof,and Jacobs's methods.The averaged CO2 fluxes of air to sea in the western Arctic Ocean or in the MSIZ of the Southern Ocean doubled that in the world oceans.
The data were collected during Chinese Arctic and Antarctic Expeditions in the western Arctic Ocean and the marginal sea ice zone (MSIZ) of the Southern Ocean,respectively in the boreal summer from July to September of 1999 and in the austral summer from December of 1999 to January of 2000.The concentrations of CO2 in surface water of the survey regions would mostly present lower than those in the atmosphere.A significant biological driving force could also been observed in summer waters in both of the above oceans.Air to sea CO2 fluxes were also calculated to compare oceanic uptake capacity of CO2 in both oceans with the world oceans using Liss,Wanninkhof,and Jacobs's methods.The averaged CO2 fluxes of air to sea in the western Arctic Ocean or in the MSIZ of the Southern Ocean doubled that in the world oceans.
2004, (4): 655-661.
Abstract:
Helium,neon and argon isotope compositions of fluid inclusions have been measured in massive sulfide samples from the Jade hydrothermal field in the central Okinawa Trough.Huid-inclusion 3He/4He ratios are between 6.2 and 10.1 times the air value (Ra),and with a mean of 7.8Ra,which are consistent with the mid-ocean ridge basalt values[3He/4He≈(6Ra~11Ra)].Values for 20Ne/22Ne are from 10.7 to 11.3,which are significantly higher than the atmospheric ratio (9.8).And the fluid-inclusion 40Ar/36Ar ratios range from 287 to 334,which are close to the atmosperic values (295.5).These results indicate that the noble gases of trapped hydrothermal fluids in massive sulfides are a mixture of mantle-and seawater-derived components,and the helium of fluid inclusions is mainly from mantle,the nelium and argon isotope compositions are mainly from seawater.
Helium,neon and argon isotope compositions of fluid inclusions have been measured in massive sulfide samples from the Jade hydrothermal field in the central Okinawa Trough.Huid-inclusion 3He/4He ratios are between 6.2 and 10.1 times the air value (Ra),and with a mean of 7.8Ra,which are consistent with the mid-ocean ridge basalt values[3He/4He≈(6Ra~11Ra)].Values for 20Ne/22Ne are from 10.7 to 11.3,which are significantly higher than the atmospheric ratio (9.8).And the fluid-inclusion 40Ar/36Ar ratios range from 287 to 334,which are close to the atmosperic values (295.5).These results indicate that the noble gases of trapped hydrothermal fluids in massive sulfides are a mixture of mantle-and seawater-derived components,and the helium of fluid inclusions is mainly from mantle,the nelium and argon isotope compositions are mainly from seawater.
2004, (4): 663-672.
Abstract:
The fractal characteristics of tidal creeks in the Gaizhou Beach are analyzed based on high-resolution images fusion of Landsat TM and ERS-2,and then the graphic models and characteristics of converse information tree of tidal creeks in the Gaizhou Beach are established.A calculation model is established based on the above results,and at the same time,quantitative calculation of the evolution characteristics and the diversity between the northern and the southern parts of the Gaizhou Beach is carried out.By the supervised classification of these images,distribution and areas of high tidal flats,middle tidal flats and low tidal flats in the Gaizhou Beach are studied quantitatively,and image charactistics of seashell habitats in the Gaizhou Beach and the correlation between mudflat distribution and seashell habitats are studied.At last,the engineering problems in the Gaizhou Beach are discussed.
The fractal characteristics of tidal creeks in the Gaizhou Beach are analyzed based on high-resolution images fusion of Landsat TM and ERS-2,and then the graphic models and characteristics of converse information tree of tidal creeks in the Gaizhou Beach are established.A calculation model is established based on the above results,and at the same time,quantitative calculation of the evolution characteristics and the diversity between the northern and the southern parts of the Gaizhou Beach is carried out.By the supervised classification of these images,distribution and areas of high tidal flats,middle tidal flats and low tidal flats in the Gaizhou Beach are studied quantitatively,and image charactistics of seashell habitats in the Gaizhou Beach and the correlation between mudflat distribution and seashell habitats are studied.At last,the engineering problems in the Gaizhou Beach are discussed.
2004, (4): 673-685.
Abstract:
Phylogenetic diversity of Form I and Form Ⅱ ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) large subunit (rbcL) genes in the inshore and offshore areas of the East China Sea were investigated.Two new primer sets were designed for amplifying partial sequences of rbcL genes from Proteobacteria.Four rbcL gene clone libraries were constructed by amplification and cloning of approximately 640~800 bp sequences of bacterioplankton populations.The method of screening library by denaturing gradient gel electrophoresis (DGGE) was introduced.The results show that the diversity of Form I is higher in offshore waters with higher salinity and lower productivity,while that of Form Ⅱ is higher at the inshore station where salinity is lower and productivity is higher.Several clusters of sequences obtained are deeply rooted and show low similarity (60%~78%) to the known rbcL in existing databases.The degree of diversity of rbcL genes is directly related to environmental variables,including temperature,salinity,pH,dissolved oxygen,etc.These results indicate that rbcL gene can be used as an effective indicator for genetic diversity and population variability of bacterioplankton with the ability of carbon dioxide fixation in the sea.
Phylogenetic diversity of Form I and Form Ⅱ ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) large subunit (rbcL) genes in the inshore and offshore areas of the East China Sea were investigated.Two new primer sets were designed for amplifying partial sequences of rbcL genes from Proteobacteria.Four rbcL gene clone libraries were constructed by amplification and cloning of approximately 640~800 bp sequences of bacterioplankton populations.The method of screening library by denaturing gradient gel electrophoresis (DGGE) was introduced.The results show that the diversity of Form I is higher in offshore waters with higher salinity and lower productivity,while that of Form Ⅱ is higher at the inshore station where salinity is lower and productivity is higher.Several clusters of sequences obtained are deeply rooted and show low similarity (60%~78%) to the known rbcL in existing databases.The degree of diversity of rbcL genes is directly related to environmental variables,including temperature,salinity,pH,dissolved oxygen,etc.These results indicate that rbcL gene can be used as an effective indicator for genetic diversity and population variability of bacterioplankton with the ability of carbon dioxide fixation in the sea.
2004, (4): 687-697.
Abstract:
The development of the phytoplankton community was studied in the Jiaozhou Bay during the spring to neap tide in August 2001,through three cruises and a 15 d continuous observation.This investigation indicates that diatom cell abundance increased sharply following the end of a spring tide,from 9 cells/cm3 to a peak of 94 cells/cm3.The dominant species composition and abundance show a quick species sequence from spring to neap tide,and the dominant species at the start phase is Skeletomena costatum,then changes to Chaetoceros curvisetus,finally it changes to Eucampia zodiacus.Silicate concentration increases during spring tide,as a result of nutrient replenishment from the water-sediment interface,its initial average concentration in neap tide is 1.39 μmol/dm3 and reached the peak average concentration of 8.40 μmol/dm3 in spring tide.But the nitrogen concentration dropped due to dilution by the low nitrogen seawater from the Huanghai Sea,its initial average concentration in neap tide is 67 μmol/dm3 and decreased to the average concentration of 54 μmol/dm3 in spring tide.The degree of silicon limitation was decreased and phytoplankton,especially diatoms,responds immediately after nutrient replenishment in the water column.Skeletonmea costatum,as one of the dominant species in the Jiaozhou Bay,shows a quicker response to nutrient availability than Eucampia zodiacus and Chaetoceros curvisetus.It is proposed that dominant species composition and water column stability synchronously determine the development of phytoplankton summer blooms in the Jiaozhou bay.
The development of the phytoplankton community was studied in the Jiaozhou Bay during the spring to neap tide in August 2001,through three cruises and a 15 d continuous observation.This investigation indicates that diatom cell abundance increased sharply following the end of a spring tide,from 9 cells/cm3 to a peak of 94 cells/cm3.The dominant species composition and abundance show a quick species sequence from spring to neap tide,and the dominant species at the start phase is Skeletomena costatum,then changes to Chaetoceros curvisetus,finally it changes to Eucampia zodiacus.Silicate concentration increases during spring tide,as a result of nutrient replenishment from the water-sediment interface,its initial average concentration in neap tide is 1.39 μmol/dm3 and reached the peak average concentration of 8.40 μmol/dm3 in spring tide.But the nitrogen concentration dropped due to dilution by the low nitrogen seawater from the Huanghai Sea,its initial average concentration in neap tide is 67 μmol/dm3 and decreased to the average concentration of 54 μmol/dm3 in spring tide.The degree of silicon limitation was decreased and phytoplankton,especially diatoms,responds immediately after nutrient replenishment in the water column.Skeletonmea costatum,as one of the dominant species in the Jiaozhou Bay,shows a quicker response to nutrient availability than Eucampia zodiacus and Chaetoceros curvisetus.It is proposed that dominant species composition and water column stability synchronously determine the development of phytoplankton summer blooms in the Jiaozhou bay.
2004, (4): 699-707.
Abstract:
To clarify cuttlefish phylogeny,mitochondrial cytochrome c oxidase subunit Ⅰ (COI) gene and partial 16S rRNA gene are sequenced for 13 cephalopod species.Phylogenetic trees are constructed,with the neighbor-joining method.Coleoids are divided into two main lineages,Decabrachia and Octobrachia.The monophyly of the order Sepioidea,which includes the families Sepiidae,Sepiolidae and Idiosepiidae,is not supported.From the two families of Sepioidea examined,the Sepiolidae are polyphyletic and are excluded from the order.On the basis of 16S rRNA and amino acid of COI gene sequences data,the two genera (Sepiella and Sepia) from the Sepiidae can be distinguished,but do not have a visible boundary using COI gene sequences.The reason is explained.This suggests that the 16S rDNA of cephalopods is a precious tool to analyze taxonomic relationships at the genus level,and COI gene is fitter at a higher taxonomic level (i.e.,family).
To clarify cuttlefish phylogeny,mitochondrial cytochrome c oxidase subunit Ⅰ (COI) gene and partial 16S rRNA gene are sequenced for 13 cephalopod species.Phylogenetic trees are constructed,with the neighbor-joining method.Coleoids are divided into two main lineages,Decabrachia and Octobrachia.The monophyly of the order Sepioidea,which includes the families Sepiidae,Sepiolidae and Idiosepiidae,is not supported.From the two families of Sepioidea examined,the Sepiolidae are polyphyletic and are excluded from the order.On the basis of 16S rRNA and amino acid of COI gene sequences data,the two genera (Sepiella and Sepia) from the Sepiidae can be distinguished,but do not have a visible boundary using COI gene sequences.The reason is explained.This suggests that the 16S rDNA of cephalopods is a precious tool to analyze taxonomic relationships at the genus level,and COI gene is fitter at a higher taxonomic level (i.e.,family).
2004, (4): 709-716.
Abstract:
The fragments of 350 bp in 28S rRNA from the closely related monogenea of trematoda,Neobenedenia girellae and N.melleni are obtained by polymerase chain reaction (PCR) amplified using a couple of special primers and then sequenced.The results show that the comparison of 28S rRNA sequences,with only a base varying in 337bp accounting for 0.3% genetic difference,from the relative species N.girellae and N.melleni parasitized on the different fishes in different farms displays that they possess a very high genetic similarity of 99.7%,higher than that of 99.41% for the single species N.melleni sampled in different areas,and the intraspecific divergence of N.melleni is 0.59%.Meanwhile,the interspecific differences between the two Neobenedenia and three Benedenia (i.e.,B.lutjani,B.rohdei and B.seriolae) range from 2.08% to11.73%.In addition,UPGMA and MP molecular phylogenetic trees are constructed and proved to be consistent with each other.Though the morphological characteristics and the results of genetic diversity for the two Neobenedenia show a high similarity,whether they belong to a single species or not are still undefined,and the more genes of them should be further investigated,in combination with the systematical and detailed morphological study.
The fragments of 350 bp in 28S rRNA from the closely related monogenea of trematoda,Neobenedenia girellae and N.melleni are obtained by polymerase chain reaction (PCR) amplified using a couple of special primers and then sequenced.The results show that the comparison of 28S rRNA sequences,with only a base varying in 337bp accounting for 0.3% genetic difference,from the relative species N.girellae and N.melleni parasitized on the different fishes in different farms displays that they possess a very high genetic similarity of 99.7%,higher than that of 99.41% for the single species N.melleni sampled in different areas,and the intraspecific divergence of N.melleni is 0.59%.Meanwhile,the interspecific differences between the two Neobenedenia and three Benedenia (i.e.,B.lutjani,B.rohdei and B.seriolae) range from 2.08% to11.73%.In addition,UPGMA and MP molecular phylogenetic trees are constructed and proved to be consistent with each other.Though the morphological characteristics and the results of genetic diversity for the two Neobenedenia show a high similarity,whether they belong to a single species or not are still undefined,and the more genes of them should be further investigated,in combination with the systematical and detailed morphological study.
2004, (4): 717-723.
Abstract:
Five strains of antarctic bacteria producing extracellular low-temperature lipase are screened from seawater collected by CTD during the Chinese 18th Antarctic Scientific Expedition.Their phylogenetic positions on the basis of amplification,comparison and analysis of almost complete 16S rDNA sequence are determined by neighbor-joining analysis.Phylogenetic analysis indicates that all of these five strains belong to γ-proteobacteria.The strains 1-1-10-2 and 9-2 are classified as genus Pseudoalteromonas sp.and genus Psychrobacter sp.respectively.The strains 2-5-10-1,2-2-2-1 and 1-2-8-1 are classified as genus Moritella sp.
Five strains of antarctic bacteria producing extracellular low-temperature lipase are screened from seawater collected by CTD during the Chinese 18th Antarctic Scientific Expedition.Their phylogenetic positions on the basis of amplification,comparison and analysis of almost complete 16S rDNA sequence are determined by neighbor-joining analysis.Phylogenetic analysis indicates that all of these five strains belong to γ-proteobacteria.The strains 1-1-10-2 and 9-2 are classified as genus Pseudoalteromonas sp.and genus Psychrobacter sp.respectively.The strains 2-5-10-1,2-2-2-1 and 1-2-8-1 are classified as genus Moritella sp.
2004, (4): 725-732.
Abstract:
An incubating temperature of 15℃ is used to induce triploidy in Eriocheir sinensis through inhibition of the release of polar body Ⅱ,and that of 18℃ to induce tetraploidy through inhibition of the first cleavage.Flow cytometry is used to identify the ploidy in different developmental stages.For induction of triploidy in fertilized eggs in vitro,the highest induction rate observed in blastula by cytochalasin B,6-DMAP and KC1 is 49.1%,51.7% and 77.5%,respectively.In the KCl treatment of pregnant crabs with the fertilized eggs,the highest triploid induction rate observed in the zoea is 85.3%.For induction of tetraploidy,the highest induction rate observed in the blastula by cytochaslasin B,6-DMAP and KCl is 50.3%,54.9% and 79.8% respectively.In the KC1 treatment of pregnant crabs with the fertilized eggs,the highest induction rate in zoea is 27.3%.Through this study such difficulty as in vitro culture is overcome.Triploid zoea Eriocheir sinensis has been developed for the first time.The induction rate of tetraploid zoea has also been greatly improved.
An incubating temperature of 15℃ is used to induce triploidy in Eriocheir sinensis through inhibition of the release of polar body Ⅱ,and that of 18℃ to induce tetraploidy through inhibition of the first cleavage.Flow cytometry is used to identify the ploidy in different developmental stages.For induction of triploidy in fertilized eggs in vitro,the highest induction rate observed in blastula by cytochalasin B,6-DMAP and KC1 is 49.1%,51.7% and 77.5%,respectively.In the KCl treatment of pregnant crabs with the fertilized eggs,the highest triploid induction rate observed in the zoea is 85.3%.For induction of tetraploidy,the highest induction rate observed in the blastula by cytochaslasin B,6-DMAP and KCl is 50.3%,54.9% and 79.8% respectively.In the KC1 treatment of pregnant crabs with the fertilized eggs,the highest induction rate in zoea is 27.3%.Through this study such difficulty as in vitro culture is overcome.Triploid zoea Eriocheir sinensis has been developed for the first time.The induction rate of tetraploid zoea has also been greatly improved.
2004, (4): 733-739.
Abstract:
On the hasis of the reason that the offshore oil development areas in the northern South China Sea are at greater depth,more hazardous conditions and distance from shore,the methods and technologies used in coastal waters are not feasible because of the higher risk of losing investigation equipment or facilities.A series of methods and technologies for offshore fouling investigation that have been successfully applied is given in detail and it is hoped that the experience can be helpful for further studies.
On the hasis of the reason that the offshore oil development areas in the northern South China Sea are at greater depth,more hazardous conditions and distance from shore,the methods and technologies used in coastal waters are not feasible because of the higher risk of losing investigation equipment or facilities.A series of methods and technologies for offshore fouling investigation that have been successfully applied is given in detail and it is hoped that the experience can be helpful for further studies.
2004, (4): 741-746.
Abstract:
The wave relative frequency in the coordinate system moving with current and the angle between the direction of wave propagation and that of current are computed based on the wave dispersion relation.The current field is computed by solving the depth averaged shallow water equations.The wave field is computed by solving the mildslope equation which has taken the current's effect into account.A numerical model is established using a finite element method for simulating the wave shoaling and diffraction in current over a mild-slope,and the numerical results are reasonable to compare with the experimental data.
The wave relative frequency in the coordinate system moving with current and the angle between the direction of wave propagation and that of current are computed based on the wave dispersion relation.The current field is computed by solving the depth averaged shallow water equations.The wave field is computed by solving the mildslope equation which has taken the current's effect into account.A numerical model is established using a finite element method for simulating the wave shoaling and diffraction in current over a mild-slope,and the numerical results are reasonable to compare with the experimental data.
2004, (4): 747-756.
Abstract:
A fast multipole methodology (FMM) is developed as a numerical approach to reduce the computational cost and memory requirements in solving large-scale problems.It is applied to the boundary element method (BEM) for threedimensional potential flow problems.The algorithm based on mixed multipole expansion and numerical integration is implemented in combination with an iterative solver.Numerical examinations,on Dirichlet and Neumann problems,are carried out to demonstrate the capability and accuracy of the present method.It has been shown that the method has evident advantages in saving memory and computing time when used to solve huge-scale problems which may be prohibitive for the traditional BEM implementation.
A fast multipole methodology (FMM) is developed as a numerical approach to reduce the computational cost and memory requirements in solving large-scale problems.It is applied to the boundary element method (BEM) for threedimensional potential flow problems.The algorithm based on mixed multipole expansion and numerical integration is implemented in combination with an iterative solver.Numerical examinations,on Dirichlet and Neumann problems,are carried out to demonstrate the capability and accuracy of the present method.It has been shown that the method has evident advantages in saving memory and computing time when used to solve huge-scale problems which may be prohibitive for the traditional BEM implementation.
2004, (4): 757-765.
Abstract:
A new analytical method is proposed to analyze the force acting on a rectangular oscillating buoy due to linear waves.In the method a new analytical expression for the diffraction velocity potential is obtained first by use of the eigenfunction expansion method and then the wave excitation force is calculated by use of the known incident wave potential and the diffraction potential.Compared with the classical analytical method,it can be seen that the present method is simpler for a two-dimensional problem due to the comparable effort needed for the computation of diffraction potential and for that of radiated potential.To verify the correctness of the method,a classical example in the reference is recomputed and the obtained results are in good accordance with those by use of other methods,which shows that the present method is correct.
A new analytical method is proposed to analyze the force acting on a rectangular oscillating buoy due to linear waves.In the method a new analytical expression for the diffraction velocity potential is obtained first by use of the eigenfunction expansion method and then the wave excitation force is calculated by use of the known incident wave potential and the diffraction potential.Compared with the classical analytical method,it can be seen that the present method is simpler for a two-dimensional problem due to the comparable effort needed for the computation of diffraction potential and for that of radiated potential.To verify the correctness of the method,a classical example in the reference is recomputed and the obtained results are in good accordance with those by use of other methods,which shows that the present method is correct.
