2002 Vol. 21, No. 3
Display Method:
2002, (3): 315-330.
Abstract:
The differences of temperature, salinity distribution characteristics and structure of circulation in the upper layer of the South China Sea (SCS) are analyzed, based on the CTD and ADCP data from the two intensive surveyed cruises (IOP1:April 10-May 5; IOP2:June 12-July 6) and carried out before and after the Asian monsoon burst (May 25) during the South China Sea Monsoon Experiment (SCSMEX) in 1998. The results showed that field of temperature in the upper layer of the SCS distinctly changed before and after the monsoon burst, the average surface temperature increased by 0.75℃, with its influence down to the depth of 500 m. The interaction of the local circulation in some areas resulted in the complexity and variability of the temperature and salinity structure in the upper layer, and the alternating distribution of cold and warm water regions (blocks). The high salinity subsurface water obviously intruded into the SCS from the Northwest Pacific, but only limited to the area of southwest of Taiwan Island, and the low salinity intermediate water flowed from the SCS to the North west Pacific. The circulation fidd of the SCS in the summer mainly consisted of cyclonic and anticyclonic eddies (rings). With the burst of the monsoon, the intensity and amount of the anticyclonic or the cyclonic eddies (rings) would vary, showing the complex distribution pattems and variations. The result analyzed by the isopycnic surface method coincided extremely with those by in situ survey (ADCP),which showed that the formation of circulation in the SCS was mainly controlled by the internal mass field, that is, dominated by the geostrophic component.
The differences of temperature, salinity distribution characteristics and structure of circulation in the upper layer of the South China Sea (SCS) are analyzed, based on the CTD and ADCP data from the two intensive surveyed cruises (IOP1:April 10-May 5; IOP2:June 12-July 6) and carried out before and after the Asian monsoon burst (May 25) during the South China Sea Monsoon Experiment (SCSMEX) in 1998. The results showed that field of temperature in the upper layer of the SCS distinctly changed before and after the monsoon burst, the average surface temperature increased by 0.75℃, with its influence down to the depth of 500 m. The interaction of the local circulation in some areas resulted in the complexity and variability of the temperature and salinity structure in the upper layer, and the alternating distribution of cold and warm water regions (blocks). The high salinity subsurface water obviously intruded into the SCS from the Northwest Pacific, but only limited to the area of southwest of Taiwan Island, and the low salinity intermediate water flowed from the SCS to the North west Pacific. The circulation fidd of the SCS in the summer mainly consisted of cyclonic and anticyclonic eddies (rings). With the burst of the monsoon, the intensity and amount of the anticyclonic or the cyclonic eddies (rings) would vary, showing the complex distribution pattems and variations. The result analyzed by the isopycnic surface method coincided extremely with those by in situ survey (ADCP),which showed that the formation of circulation in the SCS was mainly controlled by the internal mass field, that is, dominated by the geostrophic component.
2002, (3): 331-343.
Abstract:
The South China Sea warm water (SCSWW) is identified as the warm water body with temperature no less than 28℃. There are three stages in the seasonal variation of the SCSWW. The SCSWW expands rapidly and deepens quickly in the developing stage. The warm water thickness decreases near the coast of Vietnam and increases near Palawan Island in the steady stage. The SCSWW flinches southward while its thickness off Palawan Island remains no less than 50 m in the flinching stage. The maximum thickness of the SCSWW is always located near the southeastern SCS. The seasonal variation of the SCSWW has a close relationship with seasonal variation of the thermocline. According to the analysis of the numerical experiment results from the Princeton Ocean Model (POM),the mechanism of the seasonal variation of the SCSWW can be interpreted as:(1) in the developing stage, the rapidly expanding and thickening feature of the SCSWW is mainly due to buoyancy flux effect (67% contribution). The weak wind and anticyclonic wind stress curl (22% contribution) present an environment which facilitates the accumulation of warm water; (2) in the steady stage, the decrease feature near the Vietnam coast and increase eature in southeast of the SCSWW thickness are mainly caused by wind stress (70% contribution); (3) in the flinching stage, the thickness reduction of the SCSWW is mainly due to upwelling and enhanced turbulent mixing caused by wind stress accounts for 60%).
The South China Sea warm water (SCSWW) is identified as the warm water body with temperature no less than 28℃. There are three stages in the seasonal variation of the SCSWW. The SCSWW expands rapidly and deepens quickly in the developing stage. The warm water thickness decreases near the coast of Vietnam and increases near Palawan Island in the steady stage. The SCSWW flinches southward while its thickness off Palawan Island remains no less than 50 m in the flinching stage. The maximum thickness of the SCSWW is always located near the southeastern SCS. The seasonal variation of the SCSWW has a close relationship with seasonal variation of the thermocline. According to the analysis of the numerical experiment results from the Princeton Ocean Model (POM),the mechanism of the seasonal variation of the SCSWW can be interpreted as:(1) in the developing stage, the rapidly expanding and thickening feature of the SCSWW is mainly due to buoyancy flux effect (67% contribution). The weak wind and anticyclonic wind stress curl (22% contribution) present an environment which facilitates the accumulation of warm water; (2) in the steady stage, the decrease feature near the Vietnam coast and increase eature in southeast of the SCSWW thickness are mainly caused by wind stress (70% contribution); (3) in the flinching stage, the thickness reduction of the SCSWW is mainly due to upwelling and enhanced turbulent mixing caused by wind stress accounts for 60%).
2002, (3): 345-354.
Abstract:
The sea surface height anomaly (SSHA) and geostrophic circulation in the South ChinaSea (SCS) are studied using TOPEX/POSEIDON (T/P) altimetry data. The SSHA, which is obtained after tidal correction based on the tidal results from T/P data, is predominated by seasonal alternating monsoons. The results reveal that the SSHA in the central part of the SCS is positive in spring and summer, but negative in autumn and winter. It is also found that the SSHA in the SCS can be approached with the sum of tidal constituents SA and SSA. The geostrophic circulations in the SCS are calculated according to sea surface dynamic topography, which is the sum of SSHA and mean sea surface height. It is suggested that the circulation in the upper layer of the SCS is generally cyclonic and notably western intensified during autumn and winter, while the western intensification is weak during spring and summer. It is also indicated that the Kuroshio intrudes into the northeastern SCS throuth the Luzon Strait in winter. But there is no indication of Kuroshio intruding into the SCS in summer.
The sea surface height anomaly (SSHA) and geostrophic circulation in the South ChinaSea (SCS) are studied using TOPEX/POSEIDON (T/P) altimetry data. The SSHA, which is obtained after tidal correction based on the tidal results from T/P data, is predominated by seasonal alternating monsoons. The results reveal that the SSHA in the central part of the SCS is positive in spring and summer, but negative in autumn and winter. It is also found that the SSHA in the SCS can be approached with the sum of tidal constituents SA and SSA. The geostrophic circulations in the SCS are calculated according to sea surface dynamic topography, which is the sum of SSHA and mean sea surface height. It is suggested that the circulation in the upper layer of the SCS is generally cyclonic and notably western intensified during autumn and winter, while the western intensification is weak during spring and summer. It is also indicated that the Kuroshio intrudes into the northeastern SCS throuth the Luzon Strait in winter. But there is no indication of Kuroshio intruding into the SCS in summer.
2002, (3): 355-371.
Abstract:
Striping is a common phenomenon in remote sensing imagery acquired by most spaceborne and airborne multispectral sensors. In contrast to the destriping of the images of optoelectronic mechanical scanners, fewer work has been done for push-broom CCD images. Based on the characteristics of HY-1 push-broom multispectral CCD camera and its prelaunch radiometric calibration results, the striping features are analyzed and a quantitative striping removal algorithm is proposed. The algorithm is to obtain the inter-detector equalization curves to reflect the differences between detectors by statistic analysis of the satellite imagery data set, and image stripes arising from the nonuniformity of the detectors of the CCD array can be removed using the estimated equalization curves. The preliminary results show that this method can effectively remove the stripes and preserve the radiometric accuracy of the raw data at the same time.
Striping is a common phenomenon in remote sensing imagery acquired by most spaceborne and airborne multispectral sensors. In contrast to the destriping of the images of optoelectronic mechanical scanners, fewer work has been done for push-broom CCD images. Based on the characteristics of HY-1 push-broom multispectral CCD camera and its prelaunch radiometric calibration results, the striping features are analyzed and a quantitative striping removal algorithm is proposed. The algorithm is to obtain the inter-detector equalization curves to reflect the differences between detectors by statistic analysis of the satellite imagery data set, and image stripes arising from the nonuniformity of the detectors of the CCD array can be removed using the estimated equalization curves. The preliminary results show that this method can effectively remove the stripes and preserve the radiometric accuracy of the raw data at the same time.
2002, (3): 373-384.
Abstract:
Non-destructive γ spectrum analyses of 20 polymetallic nodules from the eastern Pacific were carried out. Numerous nuclides, such as 238U, 230Th, 226Ra, 210Pb, 208Ra, 228Th, 235U, 227Ac (or 231Pa) and 40K were detected. The count rates of the nuclides in the top or bottom side of nodules facing detector were measured and the ratio R of the count rates of nuclides in the top and the bottom sides was obtained. From counts and ratios, some useful information relating to the growth and movement of the nodules, the source of nuclide and relationship between those and environment can be gotten. A new method for clear distinction between the top and bottom sides of the nodule based on the R value of 226Ra or 210Pb was developed. In addition, one can infer the turnover of nodules according to the R value of 230Th.
Non-destructive γ spectrum analyses of 20 polymetallic nodules from the eastern Pacific were carried out. Numerous nuclides, such as 238U, 230Th, 226Ra, 210Pb, 208Ra, 228Th, 235U, 227Ac (or 231Pa) and 40K were detected. The count rates of the nuclides in the top or bottom side of nodules facing detector were measured and the ratio R of the count rates of nuclides in the top and the bottom sides was obtained. From counts and ratios, some useful information relating to the growth and movement of the nodules, the source of nuclide and relationship between those and environment can be gotten. A new method for clear distinction between the top and bottom sides of the nodule based on the R value of 226Ra or 210Pb was developed. In addition, one can infer the turnover of nodules according to the R value of 230Th.
2002, (3): 385-394.
Abstract:
Based on the test data in dynamic water and static water, the main factors, which influence the fine sediment flocculation, are analyzed with a gray model method of correlation theory. It is shown that the main influencing factors are water temperature, settling time, salinity, grain size, sediment concentration and current velocity according to the correlation coefficients. Among them, the salinity and the sediment grain size are critical type influencing factors (CrTIF); the settling time, the sediment concentration and the velocity are continuous type influencing factors (CoTIF); and the water temperature has the characteristics of both. When the critical values of CrTIF are reached or exceeded,the fine sediments will be flocculated, but values of CrTIF will not influence the settlement strength of flocs. The influence of CoTIF is continuous. The values of the CoTIF will not only influence the occurrence of flocculation but also the settlement strength of the flocs.
Based on the test data in dynamic water and static water, the main factors, which influence the fine sediment flocculation, are analyzed with a gray model method of correlation theory. It is shown that the main influencing factors are water temperature, settling time, salinity, grain size, sediment concentration and current velocity according to the correlation coefficients. Among them, the salinity and the sediment grain size are critical type influencing factors (CrTIF); the settling time, the sediment concentration and the velocity are continuous type influencing factors (CoTIF); and the water temperature has the characteristics of both. When the critical values of CrTIF are reached or exceeded,the fine sediments will be flocculated, but values of CrTIF will not influence the settlement strength of flocs. The influence of CoTIF is continuous. The values of the CoTIF will not only influence the occurrence of flocculation but also the settlement strength of the flocs.
2002, (3): 395-405.
Abstract:
Eighteen samples of hydrothermal sediments from the Jade hydrotherrnal field in the central Okinawa Trough have been analyzed. Sulfur isotopic values for 10 sulfide samples vary from 5.2×10-3to 7.2×10-3, δ34S values for 7 sulfate samples vary from 16.3×10-3 to 22.3×10-3, and 1 native sulphur sample has a δ34S value of 8.2×10-3. The major sources of sulfur for hydrothermal sediment are intermediate to acid volcanic rocks and sea water sulfate, and it is possible that the partial sulfur of hydrothermal sediment is from the pelagic sediment by the interaction between hydrothermal fluid and sediment. The reasons of causing the distinct differences in sulfur isotopic values for sulfide samples from hydrothermal sediment (compared with other hydrothermal fields), are the differences in the sources of sulfur, the magmatic activity and the tectonic evolution in different hydrothermal fields. The sulfur evolution is a long and complex process in the seafloor hydrothermal system, involving the ascending of heating sea water, the interaction between fluid and volcanic rocks, the mixing of sea water sulfate and sulfur from intermediate to acid volcanic rocks, and the fluid/pelagic-sediment interaction. And the interaction between sea water and intermediate to acid volcanic rocks is an important mechanism for the sulfur evolution in the Jade hydrothermal field.
Eighteen samples of hydrothermal sediments from the Jade hydrotherrnal field in the central Okinawa Trough have been analyzed. Sulfur isotopic values for 10 sulfide samples vary from 5.2×10-3to 7.2×10-3, δ34S values for 7 sulfate samples vary from 16.3×10-3 to 22.3×10-3, and 1 native sulphur sample has a δ34S value of 8.2×10-3. The major sources of sulfur for hydrothermal sediment are intermediate to acid volcanic rocks and sea water sulfate, and it is possible that the partial sulfur of hydrothermal sediment is from the pelagic sediment by the interaction between hydrothermal fluid and sediment. The reasons of causing the distinct differences in sulfur isotopic values for sulfide samples from hydrothermal sediment (compared with other hydrothermal fields), are the differences in the sources of sulfur, the magmatic activity and the tectonic evolution in different hydrothermal fields. The sulfur evolution is a long and complex process in the seafloor hydrothermal system, involving the ascending of heating sea water, the interaction between fluid and volcanic rocks, the mixing of sea water sulfate and sulfur from intermediate to acid volcanic rocks, and the fluid/pelagic-sediment interaction. And the interaction between sea water and intermediate to acid volcanic rocks is an important mechanism for the sulfur evolution in the Jade hydrothermal field.
2002, (3): 407-414.
Abstract:
The food consumption and ecological conversion efficiency of a species marine pelagic and small size fish, Hyporhamphus sajori, were determined by using in situ stomach content method presented by Eggers. The results showed that:(1) the fish was taken in food all day, so empty-stomach rate was very low, taking up about 4.5% of the total determined fish number. However, the fish still has significant daily feeding rhythm. A feeding peak was found 0:00 o'clock at night, but feeding level was always high in the daytime; (2) relationship between instantaneous food content in stomach and corresponding time could be described as St=a·e-b·t. There was not significant difference of instantaneous gastric evacuation rate between two determinations, with average value being 0.13×10-2g/(g·h) (wet weight); (3) the daily food consumption tended to change in irregular waving form, with average value being (10.16×10-2±1.19×10-2) g/(g·d) (wet weight) or (55.56×10-2±6.51×10-2) kJ/(g·d). The wave distance is constant and about 14 d, but the wave height changed largely;(4) actual determining value of daily growth rate was 3.24×10-2g/(g·d) (wet weight) or 12.91×10-2kJ/(g·d), from which 31.89% (wet weight) or 23.24% kJ of ecological conversion efficiency could be obtained.
The food consumption and ecological conversion efficiency of a species marine pelagic and small size fish, Hyporhamphus sajori, were determined by using in situ stomach content method presented by Eggers. The results showed that:(1) the fish was taken in food all day, so empty-stomach rate was very low, taking up about 4.5% of the total determined fish number. However, the fish still has significant daily feeding rhythm. A feeding peak was found 0:00 o'clock at night, but feeding level was always high in the daytime; (2) relationship between instantaneous food content in stomach and corresponding time could be described as St=a·e-b·t. There was not significant difference of instantaneous gastric evacuation rate between two determinations, with average value being 0.13×10-2g/(g·h) (wet weight); (3) the daily food consumption tended to change in irregular waving form, with average value being (10.16×10-2±1.19×10-2) g/(g·d) (wet weight) or (55.56×10-2±6.51×10-2) kJ/(g·d). The wave distance is constant and about 14 d, but the wave height changed largely;(4) actual determining value of daily growth rate was 3.24×10-2g/(g·d) (wet weight) or 12.91×10-2kJ/(g·d), from which 31.89% (wet weight) or 23.24% kJ of ecological conversion efficiency could be obtained.
2002, (3): 415-422.
Abstract:
The analysis of 103 samples collected quantitatively from the southern Taiwan Strait (22°4'~24°3'N, 117°5'~119°9'E), China, in August 1997 indicates that the abundance of heterotrophic nanoflagellates (HNF) ranges from 391 to 1 846×103 cell/dm3, with an average of 949×103 cell/dm3,and 96.2% of cells are in size of 2~22 μm in all HNF met in the samples. The HNF cells are 9.83~45.79 μg/dm3 after conversion from cell number to carbon content, with an average of 22.82 μg/dm3.The HNF abundance is relatively low in comparison with other areas. The nitrogen and phosphorus nutrients of the water are lower than previous investigations, which may be caused by the El Nino. The biormass of HNF is higher in southern waters, where cell concentration is 3~5 folds higher than that in other waters, and nearly 2-fold as high as the average of the investigated areas. The HNF is mainly habitat in 0~30 m water layer. Both horizontal and vertical HNF distribution must be influenced by hydrographical dynamic process to a great extent. Continuous in situ observations of HNF indicate the 24 h diurnal rhythm, with two peaks, one in night at one station (Station 9701) and one during the period of 12:00~24:00 at another (Station 9704). The factors controlling the diurnal variation of HNF are unclear, although vertical migration of HNF is obviously.
The analysis of 103 samples collected quantitatively from the southern Taiwan Strait (22°4'~24°3'N, 117°5'~119°9'E), China, in August 1997 indicates that the abundance of heterotrophic nanoflagellates (HNF) ranges from 391 to 1 846×103 cell/dm3, with an average of 949×103 cell/dm3,and 96.2% of cells are in size of 2~22 μm in all HNF met in the samples. The HNF cells are 9.83~45.79 μg/dm3 after conversion from cell number to carbon content, with an average of 22.82 μg/dm3.The HNF abundance is relatively low in comparison with other areas. The nitrogen and phosphorus nutrients of the water are lower than previous investigations, which may be caused by the El Nino. The biormass of HNF is higher in southern waters, where cell concentration is 3~5 folds higher than that in other waters, and nearly 2-fold as high as the average of the investigated areas. The HNF is mainly habitat in 0~30 m water layer. Both horizontal and vertical HNF distribution must be influenced by hydrographical dynamic process to a great extent. Continuous in situ observations of HNF indicate the 24 h diurnal rhythm, with two peaks, one in night at one station (Station 9701) and one during the period of 12:00~24:00 at another (Station 9704). The factors controlling the diurnal variation of HNF are unclear, although vertical migration of HNF is obviously.
2002, (3): 423-435.
Abstract:
During June 1997 cruise by R/V Science No.1, observations on temporal and spatial variations of the size-fractionated phytoplankton standing stock and primary production were carried out in the Bohai Sea. The size-fractionated chlorophyll a (Chl a) and primary production, photosynthetically available radiation (PAR), as well as the related physico-oceanographic and zooplanktonic parameters were measured at five time-series observation stations representing sub-areas of the sea. Results obtained show that there were the marked features of spatial zonation of Chl a and primary production in the Bohai Sea. The values in the Laizhou Bay, the Liaodong G ulf and the Bohai Gulf were high and showed close relation with tidal fluctuations, i.e. high Chl a concentration occurred during high tide in the Laizhou Bay, and during low tide in the Liaodong Gulf and the Bohai Gulf. In the strait and the central region of the Bohai Sea, the values were relatively low and no relationship with tidal fluctuation could be found. Chlorophyll a concentration vertically decreased from surface to bottom in the Liaodong Gulf and the Bohai Gulf, while it increased in the Laizhou Bay, the strait and the central region of the Bohai Sea, and the highest value was encountered at the bottom. Size-fractionation results showed that nano-combining pico-plankton (< 20 μm) predominated in phytoplankton communities of the Bohai Sea during late spring. The average contribution to total Chi a in each station ranged 76%~95% (mean is 87%). The contribution of net (> 20μm), nano-(2~20μm) and picoplankton (< 2 μm) was 13%, 63% and 24% to total production, and 9%, 53% and 38% to total Chl a, respectively. It proved the importance of nano-and pico-plankton in phytoplankton communities in the Bohai Sea ecosystems. In this paper the factors, such as light intensity and zooplankton grazing pressure, governing standing stock and production of phytoplankton in the Bohai Sea were also discussed.
During June 1997 cruise by R/V Science No.1, observations on temporal and spatial variations of the size-fractionated phytoplankton standing stock and primary production were carried out in the Bohai Sea. The size-fractionated chlorophyll a (Chl a) and primary production, photosynthetically available radiation (PAR), as well as the related physico-oceanographic and zooplanktonic parameters were measured at five time-series observation stations representing sub-areas of the sea. Results obtained show that there were the marked features of spatial zonation of Chl a and primary production in the Bohai Sea. The values in the Laizhou Bay, the Liaodong G ulf and the Bohai Gulf were high and showed close relation with tidal fluctuations, i.e. high Chl a concentration occurred during high tide in the Laizhou Bay, and during low tide in the Liaodong Gulf and the Bohai Gulf. In the strait and the central region of the Bohai Sea, the values were relatively low and no relationship with tidal fluctuation could be found. Chlorophyll a concentration vertically decreased from surface to bottom in the Liaodong Gulf and the Bohai Gulf, while it increased in the Laizhou Bay, the strait and the central region of the Bohai Sea, and the highest value was encountered at the bottom. Size-fractionation results showed that nano-combining pico-plankton (< 20 μm) predominated in phytoplankton communities of the Bohai Sea during late spring. The average contribution to total Chi a in each station ranged 76%~95% (mean is 87%). The contribution of net (> 20μm), nano-(2~20μm) and picoplankton (< 2 μm) was 13%, 63% and 24% to total production, and 9%, 53% and 38% to total Chl a, respectively. It proved the importance of nano-and pico-plankton in phytoplankton communities in the Bohai Sea ecosystems. In this paper the factors, such as light intensity and zooplankton grazing pressure, governing standing stock and production of phytoplankton in the Bohai Sea were also discussed.
2002, (3): 437-443.
Abstract:
mRNA was isolated from the hepatopancrease of shrimp Penaeus monodon with a PolyATtract System 1000 Kit. By using mRNA as template, double-strand cDNA with EcoR I/Xho I ends was synthesized by using a ZAP Express cDNA Synthesis Kit. The cDNA was inserted into the lambda ZAP Express vector predigested with EcoR I/Xho I, and the recombinant DNA was in vitro packaged into larnbda phage with GigapackⅢ Gold packaging extracts. These recombinant phages were then used to transfect E. coli XLl-Blue MRF', and finally a cDNA expression library was constructed. The library is 7.2×105pfu in capacity and its recombination ratio is higher than 99%. The size of the inserted cDNAs was determined by EcoR I/Xho I digestion of 9 phagemids prepared by in vivo excision of plaques selected randomly from amplified cDNA library. The longest inserted cDNA is about 1.6 kb in length. The complete sequence (about 1.2 kb) of actin cDNA was amplified from the library by PCR reveals that this library contains full-length cDNAs of Penaeus modon hepatopancreas and is available for screening and expression of shrimp genes.
mRNA was isolated from the hepatopancrease of shrimp Penaeus monodon with a PolyATtract System 1000 Kit. By using mRNA as template, double-strand cDNA with EcoR I/Xho I ends was synthesized by using a ZAP Express cDNA Synthesis Kit. The cDNA was inserted into the lambda ZAP Express vector predigested with EcoR I/Xho I, and the recombinant DNA was in vitro packaged into larnbda phage with GigapackⅢ Gold packaging extracts. These recombinant phages were then used to transfect E. coli XLl-Blue MRF', and finally a cDNA expression library was constructed. The library is 7.2×105pfu in capacity and its recombination ratio is higher than 99%. The size of the inserted cDNAs was determined by EcoR I/Xho I digestion of 9 phagemids prepared by in vivo excision of plaques selected randomly from amplified cDNA library. The longest inserted cDNA is about 1.6 kb in length. The complete sequence (about 1.2 kb) of actin cDNA was amplified from the library by PCR reveals that this library contains full-length cDNAs of Penaeus modon hepatopancreas and is available for screening and expression of shrimp genes.
2002, (3): 445-449.
Abstract:
A red pigment that has better biological properties is produced by marine bacterium strain S-9801. The extraction methods, physicochemical and toxicity of the pigment have been studied.Dissolubility of pigment in the five organic solvent has been tested, and ethanol is optimally chosen for extraction. Physicochemical characteristics of this pigment was stable. The absorbance of the pigment solution was no losing when put under natural light for 10 days or treated by UV for 30 minutes, color of the pigment unchanged after 100℃ hythere for 1 h or 80℃ xerother for 2 h. The median lethal dose (LD50) of the rat by celiac injection was 670.04 mg/kg and minimum lethal dose of oral was greater than 2 000 mg/kg.
A red pigment that has better biological properties is produced by marine bacterium strain S-9801. The extraction methods, physicochemical and toxicity of the pigment have been studied.Dissolubility of pigment in the five organic solvent has been tested, and ethanol is optimally chosen for extraction. Physicochemical characteristics of this pigment was stable. The absorbance of the pigment solution was no losing when put under natural light for 10 days or treated by UV for 30 minutes, color of the pigment unchanged after 100℃ hythere for 1 h or 80℃ xerother for 2 h. The median lethal dose (LD50) of the rat by celiac injection was 670.04 mg/kg and minimum lethal dose of oral was greater than 2 000 mg/kg.
2002, (3): 451-460.
Abstract:
The reflection coefficient and the total horizontal forces of regular waves acting on the perforated caisson are experimentally investigated. The empirical relationship between reflection coefficient and the ratio of the total horizontal forces acting on the perforated caisson to those on solid vertical walls with the relative chamber width, relative water depth and porosity of perforated wall, etc. are given. Moreover, the results of the ratio of the total horizontal forces are also compared with formulas given by Chinese Harbour Design Criteria and Takahashi, which may be useful for the practical engineering application.
The reflection coefficient and the total horizontal forces of regular waves acting on the perforated caisson are experimentally investigated. The empirical relationship between reflection coefficient and the ratio of the total horizontal forces acting on the perforated caisson to those on solid vertical walls with the relative chamber width, relative water depth and porosity of perforated wall, etc. are given. Moreover, the results of the ratio of the total horizontal forces are also compared with formulas given by Chinese Harbour Design Criteria and Takahashi, which may be useful for the practical engineering application.
2002, (3): 461-467.
Abstract:
Eight common red tide species including the Dinoflagellates Ale randrium tamarense,Prorocentrum minimum, Prorocentrum mican, Diatoms Skeletonema costatum, Cerataulina pelagica, Leptocylindrus minimus, a Raphidophyte Heterosigma akashiwo and a Chrysophyte Ivohrysis galbana were chosen to study the effect of four nitrogen substrates (NO3-N, NH4-N, Urea-N,Mixed-N) on the growth of these algae. After two transfers, the results showed that at N concentration of 550μmol, NO3-N was the best nitrogen source among these four nitrogen substrates; Urea-N and Mixed-N were also good for the growth of most algae, but not as good as NO3-N for some species; NH4-N inhibited the growth of all these species except H. akashiwo. At concentrations of 280 and 50 μmnol experiments on the growth of I. galbana, P. minimum and L. minimus in NH4-N and NO3-N substrates were also performed. The results showed that the growth rates of I. galbana were not significantly different from each other in NO3-N and NH4-N substrates both concentrations of 280 and 50 μmol. In concentration of 280μmol NH4-N substrate, the growth rates of P. minimum and L. minimus were slower than in same concentration of NO3-N; At concentration of 50μmol, the growth rate of P. minimum in NH4-N was not significantly different from that in NO3-N, while the growth rate of L. minimus was only about 30% of that in NO3-N substrate.The results indicated that each alga had its own preference in N-substrate and concentration, therefore,different nitrogen substrates may play a role in red tide formation.
Eight common red tide species including the Dinoflagellates Ale randrium tamarense,Prorocentrum minimum, Prorocentrum mican, Diatoms Skeletonema costatum, Cerataulina pelagica, Leptocylindrus minimus, a Raphidophyte Heterosigma akashiwo and a Chrysophyte Ivohrysis galbana were chosen to study the effect of four nitrogen substrates (NO3-N, NH4-N, Urea-N,Mixed-N) on the growth of these algae. After two transfers, the results showed that at N concentration of 550μmol, NO3-N was the best nitrogen source among these four nitrogen substrates; Urea-N and Mixed-N were also good for the growth of most algae, but not as good as NO3-N for some species; NH4-N inhibited the growth of all these species except H. akashiwo. At concentrations of 280 and 50 μmnol experiments on the growth of I. galbana, P. minimum and L. minimus in NH4-N and NO3-N substrates were also performed. The results showed that the growth rates of I. galbana were not significantly different from each other in NO3-N and NH4-N substrates both concentrations of 280 and 50 μmol. In concentration of 280μmol NH4-N substrate, the growth rates of P. minimum and L. minimus were slower than in same concentration of NO3-N; At concentration of 50μmol, the growth rate of P. minimum in NH4-N was not significantly different from that in NO3-N, while the growth rate of L. minimus was only about 30% of that in NO3-N substrate.The results indicated that each alga had its own preference in N-substrate and concentration, therefore,different nitrogen substrates may play a role in red tide formation.
