2001 Vol. 23, No. 2
Display Method:
2001, 23(2): 1-8.
Abstract:
By means of three-dimensional POM model,which computes the eddy viscosity coefficient based on two-order turbulent closed model,the tide and tidal current in the Beibu Gulf are simulated with fine grid.In the computed region,six of islands are considered and the bottom friction coefficients are taken to be various values from the difference of sea region.The results show that: (1) comparing the computed values with those of 81 tidal observatories,the absolute mean errors for three constituent amplitudes of O1,K1 and M2 are respectively 5.6,4.6 and 6.2 cm,and the lags are respectively 7°,9° and 15°; (2) the irregular diurnal tide and regular diurnal tide dominate in the Beibu Gulf.There are a no-tide point of K1 constituent at the east side of the Thuan An and a no-tide point of O1 constituent at the west side of the Thuan An.It remains to befurther demonstrated hereafter; (3) the residual water level is less in the Beibu Gulf and its distribution trend is basically consistent with that got by Cao Diming et al.,but there is the lowest residual water level of -3.5 cm in the Qiongzhou Straits.The westward tide-induced residual current exists in the Qiongzhou Straits and the northward tide-induced residual current exists near the westshore of the Hainan Island; (4) the vertical change of horizontal velocity is not large and the direction of maximum current velocity is slightly to the left from surface to bottom,while the occurring time of maximum current velocity is generally in advance in the bottom layer.
By means of three-dimensional POM model,which computes the eddy viscosity coefficient based on two-order turbulent closed model,the tide and tidal current in the Beibu Gulf are simulated with fine grid.In the computed region,six of islands are considered and the bottom friction coefficients are taken to be various values from the difference of sea region.The results show that: (1) comparing the computed values with those of 81 tidal observatories,the absolute mean errors for three constituent amplitudes of O1,K1 and M2 are respectively 5.6,4.6 and 6.2 cm,and the lags are respectively 7°,9° and 15°; (2) the irregular diurnal tide and regular diurnal tide dominate in the Beibu Gulf.There are a no-tide point of K1 constituent at the east side of the Thuan An and a no-tide point of O1 constituent at the west side of the Thuan An.It remains to befurther demonstrated hereafter; (3) the residual water level is less in the Beibu Gulf and its distribution trend is basically consistent with that got by Cao Diming et al.,but there is the lowest residual water level of -3.5 cm in the Qiongzhou Straits.The westward tide-induced residual current exists in the Qiongzhou Straits and the northward tide-induced residual current exists near the westshore of the Hainan Island; (4) the vertical change of horizontal velocity is not large and the direction of maximum current velocity is slightly to the left from surface to bottom,while the occurring time of maximum current velocity is generally in advance in the bottom layer.
2001, 23(2): 9-17.
Abstract:
The consistency and difference of the seasonal variation of sea surface height (SSH) are analyzed and compared among the numerical model results (POM model) and the TOPEX/Poseidon satelliten observed data.It is shown that POM results of the seasonal variation of the SSH are quite similar with obsevation.The sea surface height anomaly (SSHA) field is completely opposite between winter and summer,as well as between spring and autumn.The pileup caused by Ekman transport is more obvious along the western shore in winter than the pileup along the eastern shore in summer.The maximum amplitude of seasonal oscillation of the SSH lies near the center of the Luzon cold eddy and Luzon Strait.Except spring,the SSH seasonal variation is controlled dominantly by wind the in larger area of the South China Sea.The contribution of sea surface buoyancy flux to the seasonal variation of the SSH is 20% of the total SSH variation.The contribution of wind stress to the SSH is about 80%.
The consistency and difference of the seasonal variation of sea surface height (SSH) are analyzed and compared among the numerical model results (POM model) and the TOPEX/Poseidon satelliten observed data.It is shown that POM results of the seasonal variation of the SSH are quite similar with obsevation.The sea surface height anomaly (SSHA) field is completely opposite between winter and summer,as well as between spring and autumn.The pileup caused by Ekman transport is more obvious along the western shore in winter than the pileup along the eastern shore in summer.The maximum amplitude of seasonal oscillation of the SSH lies near the center of the Luzon cold eddy and Luzon Strait.Except spring,the SSH seasonal variation is controlled dominantly by wind the in larger area of the South China Sea.The contribution of sea surface buoyancy flux to the seasonal variation of the SSH is 20% of the total SSH variation.The contribution of wind stress to the SSH is about 80%.
2001, 23(2): 18-24.
Abstract:
A partial averaging approach used to evaluate high-order moments of wave spectra was developed by Glazman.He derived out a general equation to estimate even order moments from the known spectra and defined another one for odd order which is found to be inconsistent with the essence of the partial averaging.An alternative equation for odd order moments is got strictly from random process theory based on Glazman's partial averaging idea.The new equation is then employed in the study of the statistical distribution of horizontal velocities of the water particles on the unbroken sea surface.The effect of the occurrence of wave breaking on the statistical distribution of water particle velocities is considered through the wave breaking criterion about downward acceleration.It is found that this distribution deviates from Gaussian and is asymmetric about zero vertical velocity,further,it depends on two parameters,one of which is the spectral width εu,the other is the combination βg √M4 which is related to whitecap coverage.
A partial averaging approach used to evaluate high-order moments of wave spectra was developed by Glazman.He derived out a general equation to estimate even order moments from the known spectra and defined another one for odd order which is found to be inconsistent with the essence of the partial averaging.An alternative equation for odd order moments is got strictly from random process theory based on Glazman's partial averaging idea.The new equation is then employed in the study of the statistical distribution of horizontal velocities of the water particles on the unbroken sea surface.The effect of the occurrence of wave breaking on the statistical distribution of water particle velocities is considered through the wave breaking criterion about downward acceleration.It is found that this distribution deviates from Gaussian and is asymmetric about zero vertical velocity,further,it depends on two parameters,one of which is the spectral width εu,the other is the combination βg √M4 which is related to whitecap coverage.
2001, 23(2): 26-31.
Abstract:
In order to improve the prediction of numerical tidal model in continental shelf,the open boundary conditions are optimized by assimilating the observed data into the model in which the adjoint method,based on optimal control theory,is used.The non-linear shallow water equations are considered in which the horizontal kinematic nonlinearities,nonlinear bottom friction and horizontal eddy diffusion are included.On the basis of the establishment of adjoint model and twin-experiment (Part Ⅰ),the variational assimilation results obtained by incorporating the data from tide stations with/without TOPEX/Poseidon altimeter data in the Huanghai Sea and the East China Sea for optimizing the open boundary conditions of the model are reported.The deviations of the model results before and after assimilation from the observed demonstrate the applicability of the variational assimilation.
In order to improve the prediction of numerical tidal model in continental shelf,the open boundary conditions are optimized by assimilating the observed data into the model in which the adjoint method,based on optimal control theory,is used.The non-linear shallow water equations are considered in which the horizontal kinematic nonlinearities,nonlinear bottom friction and horizontal eddy diffusion are included.On the basis of the establishment of adjoint model and twin-experiment (Part Ⅰ),the variational assimilation results obtained by incorporating the data from tide stations with/without TOPEX/Poseidon altimeter data in the Huanghai Sea and the East China Sea for optimizing the open boundary conditions of the model are reported.The deviations of the model results before and after assimilation from the observed demonstrate the applicability of the variational assimilation.
2001, 23(2): 32-39.
Abstract:
A dynamic numerical prediction model of seawater temperature for limited sea area,which was built in the study of the numerical prediction of abnormal seawater temperature in the Huanghai Sea and the East China Sea,is used to test the seawater temperature prediction near Fujian sea area.Essential adjustments have been done according to the features of this region.Two examples are selects.One is in summer (3 d) and the other is in winter (10 d).In the summer test,a typhoon is just passing by and the calculated current field reflects the response of typhoon well.In the winter test,variation tendency of the prediction seawater temperature field agrees with that in reality basically.The absolute mean error in the whole sea area is 0.6℃.The variation of the seawater temperature is mostly affected by the actions of entrainment and pumping.This is related to the topography of the strait.
A dynamic numerical prediction model of seawater temperature for limited sea area,which was built in the study of the numerical prediction of abnormal seawater temperature in the Huanghai Sea and the East China Sea,is used to test the seawater temperature prediction near Fujian sea area.Essential adjustments have been done according to the features of this region.Two examples are selects.One is in summer (3 d) and the other is in winter (10 d).In the summer test,a typhoon is just passing by and the calculated current field reflects the response of typhoon well.In the winter test,variation tendency of the prediction seawater temperature field agrees with that in reality basically.The absolute mean error in the whole sea area is 0.6℃.The variation of the seawater temperature is mostly affected by the actions of entrainment and pumping.This is related to the topography of the strait.
2001, 23(2): 40-45.
Abstract:
In this paper,a concentrative function used in statistics is designed to present the extent in which an elementary field concentrates in the spatial distribution.Its characteristics are discussed and its availability proved.From its application in the atmospheric and oceanic sciences,we can find some interesting phenomena.For example,there is a clear seasonal concentricity in the occurrence of storms in every oceanic area in a year.The stormsdense months correspond to such an geographical place that goes around anticlockwise in the tropical oceanic areas.The spatial concentricity of SST and that of cloud change with time in a year in a similar way,that is,the higher occurrence of storms,the higher concentricity of SST and cloud,maybe the higher possibility of floods,which shows possibly that SST and its distribution play important role in the formation of cloud and that the formation of storms contributes to the concentration of the cloud.
In this paper,a concentrative function used in statistics is designed to present the extent in which an elementary field concentrates in the spatial distribution.Its characteristics are discussed and its availability proved.From its application in the atmospheric and oceanic sciences,we can find some interesting phenomena.For example,there is a clear seasonal concentricity in the occurrence of storms in every oceanic area in a year.The stormsdense months correspond to such an geographical place that goes around anticlockwise in the tropical oceanic areas.The spatial concentricity of SST and that of cloud change with time in a year in a similar way,that is,the higher occurrence of storms,the higher concentricity of SST and cloud,maybe the higher possibility of floods,which shows possibly that SST and its distribution play important role in the formation of cloud and that the formation of storms contributes to the concentration of the cloud.
2001, 23(2): 46-51.
Abstract:
Analyzed are the observations(24 September to 7 October 1998,28 April to 11 May 1999) of daily solar irradiation of the Bohai Sea area and cloud.It is found that the daily solar radiation of the Bohai Sea area in spring is much greater than in autumn,and the difference of clear-day solar radiation between the observed and the theoretically calculated results in autumn is greater than in spring.It is thought that the development of something like cloud and fog resulted from the vertical transportation of sea surface moisture is the main cause.Moreover,the daily solar radiation of the Bohai Sea is calculated by an empirical formulation mainly based on cloud parameters.There is a relatively good consistency between the observation and the calculation results.It indicates that the calculation method and the parameters used in the for mulation are suitable for calculating the daily solar radiation of the Bohai Sea area in spring and autumn.
Analyzed are the observations(24 September to 7 October 1998,28 April to 11 May 1999) of daily solar irradiation of the Bohai Sea area and cloud.It is found that the daily solar radiation of the Bohai Sea area in spring is much greater than in autumn,and the difference of clear-day solar radiation between the observed and the theoretically calculated results in autumn is greater than in spring.It is thought that the development of something like cloud and fog resulted from the vertical transportation of sea surface moisture is the main cause.Moreover,the daily solar radiation of the Bohai Sea is calculated by an empirical formulation mainly based on cloud parameters.There is a relatively good consistency between the observation and the calculation results.It indicates that the calculation method and the parameters used in the for mulation are suitable for calculating the daily solar radiation of the Bohai Sea area in spring and autumn.
2001, 23(2): 52-56.
Abstract:
The narrow sense and applicable limit of practical salinity scale 1978 (PSS78) and volumetric titration using silver nitrate to measure the salinity of non-conservative ocean water are discussed,It is found that the salinity obtained by electrical conductivity method and chlorinity salinity method are obviously deviated from the absolute salinity (Sa),the density salinity scale (DSS98) proposed by the writers can be extensively used in conservative and non-conservative water samples.The characteristics of the density salinity scale are: (1) The density salinity scale is only related to seawater mass and its buoyant effect and is not influenced by the variation of seawater composition,and so,has high reliability,and repeatability of determination.(2) The salinity values measured on the DSS98 have conservative property.For ocean water samples the salinity values are the same as those determined by the PSS78,for non-conserv ative water samples,for example,samples from industrial sources,the salinity values are closer to the absolute salinity values in comparison with those measured by the PSS78 and the Knudsen method.(3) For a solution withx given solute mass,the solution concentration can be converted into the corresponding salinity by the density salinity scale using the expansion coefficient of the solution and the calibration coefficient of the partial molar volume of the solute.
The narrow sense and applicable limit of practical salinity scale 1978 (PSS78) and volumetric titration using silver nitrate to measure the salinity of non-conservative ocean water are discussed,It is found that the salinity obtained by electrical conductivity method and chlorinity salinity method are obviously deviated from the absolute salinity (Sa),the density salinity scale (DSS98) proposed by the writers can be extensively used in conservative and non-conservative water samples.The characteristics of the density salinity scale are: (1) The density salinity scale is only related to seawater mass and its buoyant effect and is not influenced by the variation of seawater composition,and so,has high reliability,and repeatability of determination.(2) The salinity values measured on the DSS98 have conservative property.For ocean water samples the salinity values are the same as those determined by the PSS78,for non-conserv ative water samples,for example,samples from industrial sources,the salinity values are closer to the absolute salinity values in comparison with those measured by the PSS78 and the Knudsen method.(3) For a solution withx given solute mass,the solution concentration can be converted into the corresponding salinity by the density salinity scale using the expansion coefficient of the solution and the calibration coefficient of the partial molar volume of the solute.
2001, 23(2): 57-61.
Abstract:
The composition and distribution of helium and oxygen isotopes in samples of seawater obtained at depths from the surface to 300 m in the West Pacific(7°~26°N,122°~130°E) are discussed in detail.The results show that both δ18O and δ3He isoline extend eastward in the Pacific side of the Luzon Strait,which may suggest that the South China Sea water intrudes into the West Pacific by the Luzon Strait.
The composition and distribution of helium and oxygen isotopes in samples of seawater obtained at depths from the surface to 300 m in the West Pacific(7°~26°N,122°~130°E) are discussed in detail.The results show that both δ18O and δ3He isoline extend eastward in the Pacific side of the Luzon Strait,which may suggest that the South China Sea water intrudes into the West Pacific by the Luzon Strait.
2001, 23(2): 62-68.
Abstract:
Trace elemental associations and Sr,Nd isotopic compositions are of important for recognition of biogenic material from mixed marine sediments.The foraminifera shell of the Okinawa Trough strongly enriches Sr,PMn and Ba,enriches Li,U,Th,Sc,Co,Cu,Pb,Y,Zn,Cr,Rb,Sb and light rare earth elements,slightly enriches V,Ga,Zr,Nb,Cd and middle rare earth elements,and is relative short of Mo,In,Sn,Cs,Hf,Ta,W,Tl,Bi and heavy rare earth elements.The mechanism of element enrichment of foraminifera is the concentrations of trace elements in sea water and selective absorption of trace elements during foraminifera living,as well as the geochemical affinity between major elements and trace elements.The REE partitioning pattern of foraminifera shell of the Okinawa Trough shows enrichment of middler are earth elements and slightly negative Ce anomaly,which are different from those of foraminifera of the Pacific Ocean.The Sr,Ndisotopic ratios of the Okinawa Trough foraminifera are 0.709769 and 0.512162,respectively,which are different not only from those of oceanic water,but also from those of river water of China.Mainland,the former is slightly higher than that of oceanic water,but much lower than that of river water,the latter is slightly lower than that of oceanic water,but higher than that of river water,which demonstrates that the Okinawa Though sea water has been influenced by river water of China.Mainland.
Trace elemental associations and Sr,Nd isotopic compositions are of important for recognition of biogenic material from mixed marine sediments.The foraminifera shell of the Okinawa Trough strongly enriches Sr,PMn and Ba,enriches Li,U,Th,Sc,Co,Cu,Pb,Y,Zn,Cr,Rb,Sb and light rare earth elements,slightly enriches V,Ga,Zr,Nb,Cd and middle rare earth elements,and is relative short of Mo,In,Sn,Cs,Hf,Ta,W,Tl,Bi and heavy rare earth elements.The mechanism of element enrichment of foraminifera is the concentrations of trace elements in sea water and selective absorption of trace elements during foraminifera living,as well as the geochemical affinity between major elements and trace elements.The REE partitioning pattern of foraminifera shell of the Okinawa Trough shows enrichment of middler are earth elements and slightly negative Ce anomaly,which are different from those of foraminifera of the Pacific Ocean.The Sr,Ndisotopic ratios of the Okinawa Trough foraminifera are 0.709769 and 0.512162,respectively,which are different not only from those of oceanic water,but also from those of river water of China.Mainland,the former is slightly higher than that of oceanic water,but much lower than that of river water,the latter is slightly lower than that of oceanic water,but higher than that of river water,which demonstrates that the Okinawa Though sea water has been influenced by river water of China.Mainland.
2001, 23(2): 69-78.
Abstract:
Linear magnetic anomalies have been found in the middle Okinawa Trough,it means that the continental crust has broken in the extension axis,oceanic crust has been formed.There is a three extension phases model in the Okinawa Trough,namely,"doming" from middle Miocene to early Pliocene (Phase Ⅰ),"extension" from Pliocene to early Pleistocene (P hase Ⅱ),and recent "spreading" (Phase Ⅲ).The magnetic anomalies for the middle Okinawa Trough are very similar to those found in the Red Sea,which shows that developing of the Okinawa Trough is going to "Red Sea stage".Being similar to the Red Sea,there area "main trough" and a "axial trough" in the Okinawa Trough.
Linear magnetic anomalies have been found in the middle Okinawa Trough,it means that the continental crust has broken in the extension axis,oceanic crust has been formed.There is a three extension phases model in the Okinawa Trough,namely,"doming" from middle Miocene to early Pliocene (Phase Ⅰ),"extension" from Pliocene to early Pleistocene (P hase Ⅱ),and recent "spreading" (Phase Ⅲ).The magnetic anomalies for the middle Okinawa Trough are very similar to those found in the Red Sea,which shows that developing of the Okinawa Trough is going to "Red Sea stage".Being similar to the Red Sea,there area "main trough" and a "axial trough" in the Okinawa Trough.
2001, 23(2): 79-85.
Abstract:
Geochemistry analysis has been done on Core E taken from (37°07'N,118°55'E,depth: 82.1 m) the Laizhou Bay in 1994.Contents of 9 kinds of invariable elements,15 kinds of microelements and lime carbonate are measured by means of ICP.The results indicate that most of the invariable elements and microelements in Core E and the ratios of Mn/Fe,Sr/Ba,Sr/Ca,Ti/Al in especial show significant changes in the boundary strata type.So they can be used as characteristic indicator to distinguish Quaternary strata.The changes of the invariable elements are primarily controlled by the host minerals,and they mainly indicate the provenance as well as the sedimentation and depositional environment.Several elements,such as Fe,Al,Ca,Mg,Mn and Ti,are very sensitive to the provenance and environment.The distributions of microelements differ in four depositional periods: late stage of Middle Pleistocene,last interglacial period,last glacial period and Holocene,and especially in the "cold period" and "warm period".The valleys in the cycle curves of most of microelements correspond with the sand bed sediments,among which there are six sand units representing "warm period" sediments,and one representing "cold period" sediments.The carbonate is on the high side in the aeolian silt sediments formed in the glacial lowering of sea level in Core E,but on the low side in the transgressive sand beds formed in interglacial period.The content variation of carbonate has a direct bearing on the grain size and the styles of sediments,and is a good indicator to the climate,environment and stratigraphic division.
Geochemistry analysis has been done on Core E taken from (37°07'N,118°55'E,depth: 82.1 m) the Laizhou Bay in 1994.Contents of 9 kinds of invariable elements,15 kinds of microelements and lime carbonate are measured by means of ICP.The results indicate that most of the invariable elements and microelements in Core E and the ratios of Mn/Fe,Sr/Ba,Sr/Ca,Ti/Al in especial show significant changes in the boundary strata type.So they can be used as characteristic indicator to distinguish Quaternary strata.The changes of the invariable elements are primarily controlled by the host minerals,and they mainly indicate the provenance as well as the sedimentation and depositional environment.Several elements,such as Fe,Al,Ca,Mg,Mn and Ti,are very sensitive to the provenance and environment.The distributions of microelements differ in four depositional periods: late stage of Middle Pleistocene,last interglacial period,last glacial period and Holocene,and especially in the "cold period" and "warm period".The valleys in the cycle curves of most of microelements correspond with the sand bed sediments,among which there are six sand units representing "warm period" sediments,and one representing "cold period" sediments.The carbonate is on the high side in the aeolian silt sediments formed in the glacial lowering of sea level in Core E,but on the low side in the transgressive sand beds formed in interglacial period.The content variation of carbonate has a direct bearing on the grain size and the styles of sediments,and is a good indicator to the climate,environment and stratigraphic division.
2001, 23(2): 86-92.
Abstract:
There are a piece of bar and a series of lagoon in Chenshantou,Rongcheng City,Shandong Peninsula,which consist of Chengshanwei bar-lagoon chain.Based on analysis of lithological features,mollusca,and 14C,the sedimentary facies,formation and evolution of Chengshanwei lagoon chain in Shandong Peninsula are studied by taking the materials of the Swan Lake as the main data.The analysis results of Cores So5,Sh1,Sh5,Sh6 in the area show that at about 7 000 a BP,sea water intruded this area and formed the Rongcheng Bay,and at about 6 000 a BP the series of half-closed lagoon appeared inside the bar.Under the observation of bar-bedding,the evolution dynamics can be analyzed after lagoon was formed.But because of the serious human activities,the human factors also impact on the process of lagoon evolution.
There are a piece of bar and a series of lagoon in Chenshantou,Rongcheng City,Shandong Peninsula,which consist of Chengshanwei bar-lagoon chain.Based on analysis of lithological features,mollusca,and 14C,the sedimentary facies,formation and evolution of Chengshanwei lagoon chain in Shandong Peninsula are studied by taking the materials of the Swan Lake as the main data.The analysis results of Cores So5,Sh1,Sh5,Sh6 in the area show that at about 7 000 a BP,sea water intruded this area and formed the Rongcheng Bay,and at about 6 000 a BP the series of half-closed lagoon appeared inside the bar.Under the observation of bar-bedding,the evolution dynamics can be analyzed after lagoon was formed.But because of the serious human activities,the human factors also impact on the process of lagoon evolution.
2001, 23(2): 93-99.
Abstract:
The observations on the cell abundance,chlorophylla concentration and productivity of phy to plankton were carried out in the Hangzhou Bay and the Changjiang Estuary to the Zhoushan Fishing Ground during the autumn of 1995.The results show that the average cell abundance is (22.68×104±63.33×104) cell/dm3 in the surface water of the survey area; average chlorophylla is (2.80±3.46)μg/dm3 and primary productivity is (692.5±1192.4) mg/ (m2·d) (C).The size-fractionated chlorophylla shows that nanoplankton and picoplankton with cell being less than 20 μm account for 71%,and they contribut to total productivity for dominant position (68%).This provs the importance of nano- and picoplankton in phytoplankton community.The photosynthesis of phytoplankton is limited by light,as there is higher suspended particulate in the estuary.The correlation of the biological parameters with euphotic depth is significance in the survey area.The phytoplankton front is situated in the Changjiang Estuary dilution water where the euphotic depth is 10~20 m,salinity is 26~32.
The observations on the cell abundance,chlorophylla concentration and productivity of phy to plankton were carried out in the Hangzhou Bay and the Changjiang Estuary to the Zhoushan Fishing Ground during the autumn of 1995.The results show that the average cell abundance is (22.68×104±63.33×104) cell/dm3 in the surface water of the survey area; average chlorophylla is (2.80±3.46)μg/dm3 and primary productivity is (692.5±1192.4) mg/ (m2·d) (C).The size-fractionated chlorophylla shows that nanoplankton and picoplankton with cell being less than 20 μm account for 71%,and they contribut to total productivity for dominant position (68%).This provs the importance of nano- and picoplankton in phytoplankton community.The photosynthesis of phytoplankton is limited by light,as there is higher suspended particulate in the estuary.The correlation of the biological parameters with euphotic depth is significance in the survey area.The phytoplankton front is situated in the Changjiang Estuary dilution water where the euphotic depth is 10~20 m,salinity is 26~32.
2001, 23(2): 100-108.
Abstract:
Fatty acid composition of the liver oils from common species of sharks and rays off southern and middle Fujian coastal waters is similar,and the major fatty acids include 16:0 (14.9%~23.7%),18:0 (5.3%~10.4%),18:1ω9(8.6%~16.9%),16:1(3.4%~7.5%),20:4 ω6(3.8%~14.7%) and 22:6ω3(10.7%~36.9%).The liver oils in allspecies are analyzed except Hypoprion sp.contains high levels of 22:6ω3(DHA),especially in Scoliodon sorrakowah.These species are therefore good sources of 22:6ω3 rich marine oils.The benthic species have a higher content of ω6 PUFA in liver oil than the pelagic species,while the contents of 22:6 ω3 and the ratios of ω3 PUFA to ω6 PUFA are relatively higher in pelagic species than in benthic ones.Fatty acid composition in the liver oils might be influenced by the feeding habit of animals.
Fatty acid composition of the liver oils from common species of sharks and rays off southern and middle Fujian coastal waters is similar,and the major fatty acids include 16:0 (14.9%~23.7%),18:0 (5.3%~10.4%),18:1ω9(8.6%~16.9%),16:1(3.4%~7.5%),20:4 ω6(3.8%~14.7%) and 22:6ω3(10.7%~36.9%).The liver oils in allspecies are analyzed except Hypoprion sp.contains high levels of 22:6ω3(DHA),especially in Scoliodon sorrakowah.These species are therefore good sources of 22:6ω3 rich marine oils.The benthic species have a higher content of ω6 PUFA in liver oil than the pelagic species,while the contents of 22:6 ω3 and the ratios of ω3 PUFA to ω6 PUFA are relatively higher in pelagic species than in benthic ones.Fatty acid composition in the liver oils might be influenced by the feeding habit of animals.
2001, 23(2): 109-116.
Abstract:
The effect of temperature,salinity on the growth of G.tenuistipitata var.liui,U.pertusa,G.filicina and NH4-N uptake by nitrogen-starved G.tenuistipitata var.liui is studied indoor.The results show that the maximal specific growth rate per day may reach as high as 8.66%,12.28%,2.24% at favorable temperature of 20~30℃,15~25℃,20~25℃ and salinity of 15~30,15~40,25~35 respectively.The addition of NaHCO3 (2.5 mmol/dm3) stimulated growth,suggesting an inorganic carbon limitation in static cultures.Nearly all NH4-N in the medium (60 μmol) are assimilated within 24 h at the combinations of 15℃,20℃,10 and 20,the uptake is slower at lower temperature (10℃) and higher salinity (40).The correlation models indicat that temperature and salinity are the major factors affecting growth and ammonium uptake.
The effect of temperature,salinity on the growth of G.tenuistipitata var.liui,U.pertusa,G.filicina and NH4-N uptake by nitrogen-starved G.tenuistipitata var.liui is studied indoor.The results show that the maximal specific growth rate per day may reach as high as 8.66%,12.28%,2.24% at favorable temperature of 20~30℃,15~25℃,20~25℃ and salinity of 15~30,15~40,25~35 respectively.The addition of NaHCO3 (2.5 mmol/dm3) stimulated growth,suggesting an inorganic carbon limitation in static cultures.Nearly all NH4-N in the medium (60 μmol) are assimilated within 24 h at the combinations of 15℃,20℃,10 and 20,the uptake is slower at lower temperature (10℃) and higher salinity (40).The correlation models indicat that temperature and salinity are the major factors affecting growth and ammonium uptake.
2001, 23(2): 117-123.
Abstract:
The perturbation method is applied to investigate the dynamics of a floating tower under irregular waves in the frequency domain.Ratio amplitude operator and spectra of surge and tension of the floating tower are calculated.At the same time the corresponding model tests are carried out in the State Key Laboratory of Ocean Engineering,Shanghai Jiaotong University.From the comparison,it can be found that the calculated results agree well with the test results.The results show that the second-order wave force has an effect on the slow oscillation of the floating tower in surge direction.The perturbation method can be used to analyze the dynamics of a floating tower.
The perturbation method is applied to investigate the dynamics of a floating tower under irregular waves in the frequency domain.Ratio amplitude operator and spectra of surge and tension of the floating tower are calculated.At the same time the corresponding model tests are carried out in the State Key Laboratory of Ocean Engineering,Shanghai Jiaotong University.From the comparison,it can be found that the calculated results agree well with the test results.The results show that the second-order wave force has an effect on the slow oscillation of the floating tower in surge direction.The perturbation method can be used to analyze the dynamics of a floating tower.
2001, 23(2): 124-131.
Abstract:
In the light of typical cases,the distribution characteristics of the wave forces exerted on semi-circular breakw aters by irregular waves are studied.It is pointed out that whether the waves going through the top of the breakwater are broken or not will produce a great impact on wave force value.Furthermore,the reasonable holing methods and the formulae to calculate the design wave forces are also proposed.
In the light of typical cases,the distribution characteristics of the wave forces exerted on semi-circular breakw aters by irregular waves are studied.It is pointed out that whether the waves going through the top of the breakwater are broken or not will produce a great impact on wave force value.Furthermore,the reasonable holing methods and the formulae to calculate the design wave forces are also proposed.
2001, 23(2): 132-141.
Abstract:
2001, 23(2): 142-148.
Abstract:
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