1985 Vol. 4, No. 4
Display Method:
1985, (4): 503-509.
Abstract:
A method of remote sensing of attenuation coefficient of sound wave in marine sediments is proposed in this paper.Under certain conditions the echo envelope has an exponential decay EXP(-βCt).When the frequency is high enough,the exponential decay would be the dominant factor in the shape of the echo envelope.Therefore,the attenuation coefficient can be estimated from the envelope.The echo as a function of time is deduced on the basis of a small-scale layering model of marine sediments.The deduction can be regarded as a description of the mechanism of the volume-scattering of high-frequency sound in marine sediment.Experiments at sea are described,and the results are given.
A method of remote sensing of attenuation coefficient of sound wave in marine sediments is proposed in this paper.Under certain conditions the echo envelope has an exponential decay EXP(-βCt).When the frequency is high enough,the exponential decay would be the dominant factor in the shape of the echo envelope.Therefore,the attenuation coefficient can be estimated from the envelope.The echo as a function of time is deduced on the basis of a small-scale layering model of marine sediments.The deduction can be regarded as a description of the mechanism of the volume-scattering of high-frequency sound in marine sediment.Experiments at sea are described,and the results are given.
1985, (4): 510-514.
Abstract:
On the basis of the simple dynamic model of circulation developed for the East China Sea in References [1] and [2],the present paper proposes a more complete one,which is basically brought into line with Reference [3].It is interesting to note that the computation results based on both the models mentioned above are the same in principle though different in detail.A comparison between numerical modeling and observations shows an agreement and the dynamics of circulation in the East China Sea reveals that the pattern of circulation is controlled by boundary force,water depth and ther-mohaline effect with the wind stress playing a minor role therein.
On the basis of the simple dynamic model of circulation developed for the East China Sea in References [1] and [2],the present paper proposes a more complete one,which is basically brought into line with Reference [3].It is interesting to note that the computation results based on both the models mentioned above are the same in principle though different in detail.A comparison between numerical modeling and observations shows an agreement and the dynamics of circulation in the East China Sea reveals that the pattern of circulation is controlled by boundary force,water depth and ther-mohaline effect with the wind stress playing a minor role therein.
1985, (4): 515-526.
Abstract:
Based on the numerical model shown in Ref.[1],a dynamic analysis is given for the storm surges caused by the four typhoons(i.e.typhoons Nos.5310,5612,6126 and 6207) on the east coast of Zhejiang and Jiangsu Provinces,in which the contributions of various dynamic factors to local surge elevation are calculated numerically,including the Coriolis force,the atmospheric pressure force,the bottom friction,the local topography and the couple nonlinear interactions between surge current and elevation as well as between surge currents themselves.Moreover,the responses of these factors to different kinds of typhoon tracks and water depths are discussed in more detail,and the effects of grid size on the computed results demonstrated.
Based on the numerical model shown in Ref.[1],a dynamic analysis is given for the storm surges caused by the four typhoons(i.e.typhoons Nos.5310,5612,6126 and 6207) on the east coast of Zhejiang and Jiangsu Provinces,in which the contributions of various dynamic factors to local surge elevation are calculated numerically,including the Coriolis force,the atmospheric pressure force,the bottom friction,the local topography and the couple nonlinear interactions between surge current and elevation as well as between surge currents themselves.Moreover,the responses of these factors to different kinds of typhoon tracks and water depths are discussed in more detail,and the effects of grid size on the computed results demonstrated.
1985, (4): 527-534.
Abstract:
The Chinese desert is one of the major sources of atmospheric mineral dust transported for a long distance to the North Pacific by the atmospheric circulation.The characteristic of the aerosol in the North Pacific is smilar to that of the aerosol in North China with a considerable concentration of mineral in spring due to the large-scale dust storm occurring in North China.The study of isotope tracer indicates that the concentration of Al is significantly related to 210Pb,suggesting that the mineral aerosol in the North Pacific may origir ate from the desert in Northwest China by using air mass trajectory analysis.About 6-12×106 tons of Chinese desert mineral dust per year would be transported to the North Pacific.
The Chinese desert is one of the major sources of atmospheric mineral dust transported for a long distance to the North Pacific by the atmospheric circulation.The characteristic of the aerosol in the North Pacific is smilar to that of the aerosol in North China with a considerable concentration of mineral in spring due to the large-scale dust storm occurring in North China.The study of isotope tracer indicates that the concentration of Al is significantly related to 210Pb,suggesting that the mineral aerosol in the North Pacific may origir ate from the desert in Northwest China by using air mass trajectory analysis.About 6-12×106 tons of Chinese desert mineral dust per year would be transported to the North Pacific.
1985, (4): 535-547.
Abstract:
The abnormally heavy precipitation occurred in the Changjiang Valley,1983 as one of the four serious flooded events in the past sixty years was directly associated with the abnormal changes of the subtropical high of the NW Pacific.Meanwhile the abnormal changes of the S.H.were correlated with the abnormally warming of SST of the tropical East Pacific and the appearance of El nino in 1982-1983,which had attained the highest intensity in this century and were reasonably correlated with the unusual variations of Southern Oscillation,SST anomalies of the Pacific Ocean,and the anomalies of the cloudness over these areas.This has once again confirmed that there exists a teleconnection between several parts of Pacific Ocean and the atmospheric circulation.A chain reaction between the abnormal weather in China and the East and the West Pacific(the tropical and the subtropical Pacific) is revealed,which may give some information for the long-range weather forecasting.
The abnormally heavy precipitation occurred in the Changjiang Valley,1983 as one of the four serious flooded events in the past sixty years was directly associated with the abnormal changes of the subtropical high of the NW Pacific.Meanwhile the abnormal changes of the S.H.were correlated with the abnormally warming of SST of the tropical East Pacific and the appearance of El nino in 1982-1983,which had attained the highest intensity in this century and were reasonably correlated with the unusual variations of Southern Oscillation,SST anomalies of the Pacific Ocean,and the anomalies of the cloudness over these areas.This has once again confirmed that there exists a teleconnection between several parts of Pacific Ocean and the atmospheric circulation.A chain reaction between the abnormal weather in China and the East and the West Pacific(the tropical and the subtropical Pacific) is revealed,which may give some information for the long-range weather forecasting.
1985, (4): 548-556.
Abstract:
In this paper the relationship between the variation of shrimp resources(which is sensitive to the sea temperature of the Huanghai and Bohai Seas) and the equatorial sea surface temperature is analysed,the results obtained showing high correlation between the two.Therefore,a new approach to studying long-term variational law of fishery resources and forecasting method is made through large-scale air-sea interaction.
In this paper the relationship between the variation of shrimp resources(which is sensitive to the sea temperature of the Huanghai and Bohai Seas) and the equatorial sea surface temperature is analysed,the results obtained showing high correlation between the two.Therefore,a new approach to studying long-term variational law of fishery resources and forecasting method is made through large-scale air-sea interaction.
DIRECT AND SIMULTANEOUS DETERMINATION OF Zn, Cd, Pb, Cu and Bi IN SEAWATER BY DERIVATIVE-VOLTAMMETRY
1985, (4): 557-563.
Abstract:
This paper suggests direct and simultaneous determinations of the reducible species of Zn,Cd,Pb,Cu and Bi in seawater made by the derivative-differential pulse anodic stripping voltammetry with a hung mercury drop electrode.The influence of Cu on the determination of Zn in this experiment condition has been studied,of which both the accuracy and precision are satisfactory.The procedure of determination is so quick,simple and convenient that the background concentration of these five elements in coastal seawaters can be determined only by adjusting the acidity of seawater to pH 2.5 and by taking 10-minutes plating time.Actual measurement time of these five elements for every sample is approximately 25 min.
This paper suggests direct and simultaneous determinations of the reducible species of Zn,Cd,Pb,Cu and Bi in seawater made by the derivative-differential pulse anodic stripping voltammetry with a hung mercury drop electrode.The influence of Cu on the determination of Zn in this experiment condition has been studied,of which both the accuracy and precision are satisfactory.The procedure of determination is so quick,simple and convenient that the background concentration of these five elements in coastal seawaters can be determined only by adjusting the acidity of seawater to pH 2.5 and by taking 10-minutes plating time.Actual measurement time of these five elements for every sample is approximately 25 min.
1985, (4): 564-572.
Abstract:
A new and simple analytical procedure has been developed for the determination of the chemical species of dissolved chromium in seawater and used to monitor the water pollution in the sea area of Xiamen.The data obtained by statistical treatment coincides with the environment situation in that sea area.
A new and simple analytical procedure has been developed for the determination of the chemical species of dissolved chromium in seawater and used to monitor the water pollution in the sea area of Xiamen.The data obtained by statistical treatment coincides with the environment situation in that sea area.
1985, (4): 573-578.
Abstract:
The separation and simultaneous determination of the traces of U and Th in seawater by IDMS is described.The detection limits of this method are 2.4×10-9 g for Th and 1.1×10-8 g for U.The concentrations of U and Th in seawater nearby Xiamen were measured,which are 3.20 ppb and 7.73 ppt respectively.The precisions fo the method are ±1.7% for U and ±3.6% for Th respectively.
The separation and simultaneous determination of the traces of U and Th in seawater by IDMS is described.The detection limits of this method are 2.4×10-9 g for Th and 1.1×10-8 g for U.The concentrations of U and Th in seawater nearby Xiamen were measured,which are 3.20 ppb and 7.73 ppt respectively.The precisions fo the method are ±1.7% for U and ±3.6% for Th respectively.
1985, (4): 579-590.
Abstract:
The South China Sea is situated at the continsntal margin of South China.In this region,there are both continental and oceanic crusts.The values of Bouguer gravity anomalies on the continental shelf are low positive or low negative.Because the depth of the Mohorovicic discontinuity in this region is about 26-32 km below sea level,the crust belongs to the continental type.The values of Bouguer gravity anomalies in the deep-sea region are more than 250 mgal and the depth of the Moho-surface is about 10-15 km below sea level,so the crust is of oceanic type.The values of gravity anomalies and depths of the Moho-surface,obtained over the continental(and island) slope,range between those regions mentioned above,so the crust belongs to the transitional type.The continental crust is inferred to be directly in contact with the oceanic crust as a result of a lithospheric fault.
The South China Sea is situated at the continsntal margin of South China.In this region,there are both continental and oceanic crusts.The values of Bouguer gravity anomalies on the continental shelf are low positive or low negative.Because the depth of the Mohorovicic discontinuity in this region is about 26-32 km below sea level,the crust belongs to the continental type.The values of Bouguer gravity anomalies in the deep-sea region are more than 250 mgal and the depth of the Moho-surface is about 10-15 km below sea level,so the crust is of oceanic type.The values of gravity anomalies and depths of the Moho-surface,obtained over the continental(and island) slope,range between those regions mentioned above,so the crust belongs to the transitional type.The continental crust is inferred to be directly in contact with the oceanic crust as a result of a lithospheric fault.
1985, (4): 591-602.
Abstract:
The Jianggang tidal flat is formed under the influence ot two strong tidal currents which converge on or diverge from Jianggang.Tidal channel and creek system is rather well developed here due to the actions of scouring,transportation as well as deposition of bottom sediments by tidal currents.Tidal channels,crisscrossing the flat,are large in scale and swift in lateral migration,which plays a role of vital importance in the reworking of the tidal flat sediments.This paper evaluates the characteristics of sediments of the tidal channels and puts forward some facies criteria for the identification of these sediments and the theory of development of tidal channels by stages,thus providing a useful base for the study of its ancient counterparts.
The Jianggang tidal flat is formed under the influence ot two strong tidal currents which converge on or diverge from Jianggang.Tidal channel and creek system is rather well developed here due to the actions of scouring,transportation as well as deposition of bottom sediments by tidal currents.Tidal channels,crisscrossing the flat,are large in scale and swift in lateral migration,which plays a role of vital importance in the reworking of the tidal flat sediments.This paper evaluates the characteristics of sediments of the tidal channels and puts forward some facies criteria for the identification of these sediments and the theory of development of tidal channels by stages,thus providing a useful base for the study of its ancient counterparts.
1985, (4): 603-614.
Abstract:
The sequence of biocalcarenites occurred on Shidao Island,the highest one among the Xisha Archipelago,is characterized by the alternation of cross-beddings and parallel beddings,which,owing to the misinterpretation of the sedimentary structures,has caused some controversies.
Three kinds of boundary surfaces have been found in the sequence:the first-order boundaries marked with the occurrence of paleosols which is nearly horizontal; the second-order boundaries between dune deposits and interdune deposits,formed by the climbing of the dunes and interdunes under the action of NE-trade wind; and the third-order boundaries of cosets inclining exclusively windward.The dune deposits have well-preserved cross-beddings on a large scale,while the interdune deposits show roughly paralled bedding.
In conclusion,the coexistence of the three boundary surfaces and the dune and interdune deposits marks the feature of the eolian biocalcarenites.
The sequence of biocalcarenites occurred on Shidao Island,the highest one among the Xisha Archipelago,is characterized by the alternation of cross-beddings and parallel beddings,which,owing to the misinterpretation of the sedimentary structures,has caused some controversies.
Three kinds of boundary surfaces have been found in the sequence:the first-order boundaries marked with the occurrence of paleosols which is nearly horizontal; the second-order boundaries between dune deposits and interdune deposits,formed by the climbing of the dunes and interdunes under the action of NE-trade wind; and the third-order boundaries of cosets inclining exclusively windward.The dune deposits have well-preserved cross-beddings on a large scale,while the interdune deposits show roughly paralled bedding.
In conclusion,the coexistence of the three boundary surfaces and the dune and interdune deposits marks the feature of the eolian biocalcarenites.
1985, (4): 615-622.
Abstract:
This paper presents the degradation of 10 strains of hydrocarbon-degrading bacteria isolated from Xiamen harbor for 8 kinds of hydrocarbon and their mixed hydrocarbons incubated for 7 days at 25℃.The results indicate that the degradation rates of different genera of bacteria,which are measured with gas chromatography,are different for 8 hydrocarbons,thus showing the differences among genera; that the degradation rates of most strains for alkane hydrocarbons are higher than those for aromatic hydrocarbons; that the mixed strains favour the degratation for mixed hydrocarbons; and that the concentration of hydrocarbon is an important factor affecting degradation rates.
This paper presents the degradation of 10 strains of hydrocarbon-degrading bacteria isolated from Xiamen harbor for 8 kinds of hydrocarbon and their mixed hydrocarbons incubated for 7 days at 25℃.The results indicate that the degradation rates of different genera of bacteria,which are measured with gas chromatography,are different for 8 hydrocarbons,thus showing the differences among genera; that the degradation rates of most strains for alkane hydrocarbons are higher than those for aromatic hydrocarbons; that the mixed strains favour the degratation for mixed hydrocarbons; and that the concentration of hydrocarbon is an important factor affecting degradation rates.
1985, (4): 623-633.
Abstract:
In seven cruises on benthic organisms in the nearshore waters(>50 m) to the west of the Taiwan Strait(23°20'-25°54'N,117°11'-119°58'E) in 1961-1964,altogether 189 stations of quantitative grabbing and 33 stations of qualitative trawling were made.
Altogether 392 species of benthic organisms have been identified.The composition was dominated by nearshore shallow water species,with tropical and subtropical species absolutely dominant.The total average of biomass was 38.0 g/m2 and average density,116.0 ind./m2.The communities of benthic organisms in the area can be classified into five communities namely,(1) Amphiura sp.-Acaudina molpadioides Community;(2) Protankyra asymmetrica-Arnphioplus pracstans-Murex trapa Community;(3) Modiolus meicalfei-Phyllophorus liuwutiensis-Armandia letocirris-Nephtys sinensis Community;(4) Branchiostoma belcheri-Solenr oseomaculatus-Marphysa sinensis- Onuphis eremita Community;(5) Iconomtra japonica-Barbatia decussata Community.
In seven cruises on benthic organisms in the nearshore waters(>50 m) to the west of the Taiwan Strait(23°20'-25°54'N,117°11'-119°58'E) in 1961-1964,altogether 189 stations of quantitative grabbing and 33 stations of qualitative trawling were made.
Altogether 392 species of benthic organisms have been identified.The composition was dominated by nearshore shallow water species,with tropical and subtropical species absolutely dominant.The total average of biomass was 38.0 g/m2 and average density,116.0 ind./m2.The communities of benthic organisms in the area can be classified into five communities namely,(1) Amphiura sp.-Acaudina molpadioides Community;(2) Protankyra asymmetrica-Arnphioplus pracstans-Murex trapa Community;(3) Modiolus meicalfei-Phyllophorus liuwutiensis-Armandia letocirris-Nephtys sinensis Community;(4) Branchiostoma belcheri-Solenr oseomaculatus-Marphysa sinensis- Onuphis eremita Community;(5) Iconomtra japonica-Barbatia decussata Community.
1985, (4): 634-640.
Abstract:
The material discussed in this report was collected at 23 stations in the north of the continental shelf of the East China Sea from October 4 to November 5,1977 with a Juday phytoplankton net(diameter 37 cm,No.20 gauze) which was towed from the bottom to the surface of the sea.The Results anlayzed show that the species composition and distributon of dinoflagellates in this region bear a close realtionship to the water mass and the sea currents.Based on the temperature ranges in which different species of dinoflagellates flourish,they may be divided into three groups:cold-water species,warm-temperate species and warm-water species.The number of the last group is more than 70% of the total.
The material discussed in this report was collected at 23 stations in the north of the continental shelf of the East China Sea from October 4 to November 5,1977 with a Juday phytoplankton net(diameter 37 cm,No.20 gauze) which was towed from the bottom to the surface of the sea.The Results anlayzed show that the species composition and distributon of dinoflagellates in this region bear a close realtionship to the water mass and the sea currents.Based on the temperature ranges in which different species of dinoflagellates flourish,they may be divided into three groups:cold-water species,warm-temperate species and warm-water species.The number of the last group is more than 70% of the total.
1985, (4): 641-647.
Abstract:
The high-efficiency tandem piston air gun is a new pneumatic seismic source with simple structure,convenient operation and low cost.It can create high-energy acoustic pulse signals,and effectively attenuate bubble responses.This paper briefly introduces the air gun with 0.8 liter at a pressure of 140 kg/cm2.The measurement shows that the gun has reached a maximum peak-peak sound pressure up to about 11.7 bar-meters.The ratio(P1-P2) is about 2.79.The energy of the acoustic pulse is concentrated within 200 Hz and the main frequency corresponding to the spectrum value is about 30 Hz.Its lowest frequency is below 10 Hz.
The high-efficiency tandem piston air gun is a new pneumatic seismic source with simple structure,convenient operation and low cost.It can create high-energy acoustic pulse signals,and effectively attenuate bubble responses.This paper briefly introduces the air gun with 0.8 liter at a pressure of 140 kg/cm2.The measurement shows that the gun has reached a maximum peak-peak sound pressure up to about 11.7 bar-meters.The ratio(P1-P2) is about 2.79.The energy of the acoustic pulse is concentrated within 200 Hz and the main frequency corresponding to the spectrum value is about 30 Hz.Its lowest frequency is below 10 Hz.
1985, (4): 648-648.
Abstract:
1985, (4): 648-649.
Abstract:
