1999 Vol. 21, No. 3
Display Method:
1999, 21(3): 1-6.
Abstract:
The contribution of the tidal flat and tidal currents advection to the generation and growth of M4 tidal component is analyzed by using a numerical modelling in a ideal semi-enclosed rectanglular bay. The result shows that the contribution of tidal flat depends not only on the location and dimension of the tidal flat, but also on the non-linearity of the tide in the bay. The amplitude of the My tidal component is inhibited by the advection in the bay where there is the M4 tide co-oscillation.
The contribution of the tidal flat and tidal currents advection to the generation and growth of M4 tidal component is analyzed by using a numerical modelling in a ideal semi-enclosed rectanglular bay. The result shows that the contribution of tidal flat depends not only on the location and dimension of the tidal flat, but also on the non-linearity of the tide in the bay. The amplitude of the My tidal component is inhibited by the advection in the bay where there is the M4 tide co-oscillation.
1999, 21(3): 7-14.
Abstract:
Abased tidal errors in TOPEX/POSEIDON(T/P) altimetric data were studied based on analyses of satellite orbit features and observations in China's near seas. The results show that in shallow waters strong tidal aliasirtg occurs in observations of T/P altimeter. Although the tidal correction provided in NASA's Geophysical Data Records works quite well for deep ocean basins, it can not effectively remove shallow water tides. However, since the main aliased tidal periods of T/P are shorter than 90 d, one can extract the longer seasonal signal of sea surface height through filtering procedure. The filtered results can then be used to study seasonal circulation(e. g.,the monsoon driven circulation in the South China Sea).Results of several filtering experiments using a FFT/IFFT filter show that T/P altimeter measurement is quite accurate. The deviations of filtered sea surface height consist very well with ground observation from tide gauges. The standard deviation between sea surface height observed by ascending and descendina orbits near a cross-over point is about 3 cm, which will satisfy demands of the South China Sea circulation studies.
Abased tidal errors in TOPEX/POSEIDON(T/P) altimetric data were studied based on analyses of satellite orbit features and observations in China's near seas. The results show that in shallow waters strong tidal aliasirtg occurs in observations of T/P altimeter. Although the tidal correction provided in NASA's Geophysical Data Records works quite well for deep ocean basins, it can not effectively remove shallow water tides. However, since the main aliased tidal periods of T/P are shorter than 90 d, one can extract the longer seasonal signal of sea surface height through filtering procedure. The filtered results can then be used to study seasonal circulation(e. g.,the monsoon driven circulation in the South China Sea).Results of several filtering experiments using a FFT/IFFT filter show that T/P altimeter measurement is quite accurate. The deviations of filtered sea surface height consist very well with ground observation from tide gauges. The standard deviation between sea surface height observed by ascending and descendina orbits near a cross-over point is about 3 cm, which will satisfy demands of the South China Sea circulation studies.
1999, 21(3): 15-29.
Abstract:
Based on hydrographic data obtained by R/V Chofu Maru during eight cruises of 1993-1994, a modified inverse method is used to compute the velocity, volume and heat transports of the Kuroshio in the East China Sea. The calculated results show that:(1) at Section PN, there are two current cores of the Kuroshio in autumn, one or two cores in other seasons. The main core always lies over the shelf break. Countercurrent always exists east of and in the deep layer under the Kuroshio;(2) at Section TK, the velocity distribution is more complicated, and it may have one, two or three current cores of the Kuroshio. Current cores often appear in the middle and northern parts of the Tokara Strait. There are westward countercurrents in the southern end and deep layer of the strait, and the countercurrent in the southern end of the strait is stronger in autumn;(3) at Section A, the Tsushima Warm Current(hereafter TSWC) core lies in the shelf break area, and its Vmax varies between 26-46 cm/s. The Huanghai Warm Current lies to the west of the TSWC, and it is weaker;(4) in 1993 and 1994 the volume transport(hereafter VT) of the Kuroshio is the smallest in spring, but it is the largest or has a larger value in summer. The average net northward VT of the Kuroshio during four seasons each year, for example through Section PN, almost has the same value for 1993 and 1994, but both is smaller than that in 1992. The average net northward VT through Sections PN and TK during the eight cruises is 27.1×106 and 25.0×106m3/s;(5) the average heat transports through Sections PN and TK are 1.99×1015 and 1.78×1015W, respectively and(6) at the computation area, heat transfer is from the ocean to the atmosphere in autumn and winter, but the direction reverses in summer, and the direction of heat transfer is uncertain in spring. The average rate of heat transfer is the largest in winter, but smaller in spring and summer.
Based on hydrographic data obtained by R/V Chofu Maru during eight cruises of 1993-1994, a modified inverse method is used to compute the velocity, volume and heat transports of the Kuroshio in the East China Sea. The calculated results show that:(1) at Section PN, there are two current cores of the Kuroshio in autumn, one or two cores in other seasons. The main core always lies over the shelf break. Countercurrent always exists east of and in the deep layer under the Kuroshio;(2) at Section TK, the velocity distribution is more complicated, and it may have one, two or three current cores of the Kuroshio. Current cores often appear in the middle and northern parts of the Tokara Strait. There are westward countercurrents in the southern end and deep layer of the strait, and the countercurrent in the southern end of the strait is stronger in autumn;(3) at Section A, the Tsushima Warm Current(hereafter TSWC) core lies in the shelf break area, and its Vmax varies between 26-46 cm/s. The Huanghai Warm Current lies to the west of the TSWC, and it is weaker;(4) in 1993 and 1994 the volume transport(hereafter VT) of the Kuroshio is the smallest in spring, but it is the largest or has a larger value in summer. The average net northward VT of the Kuroshio during four seasons each year, for example through Section PN, almost has the same value for 1993 and 1994, but both is smaller than that in 1992. The average net northward VT through Sections PN and TK during the eight cruises is 27.1×106 and 25.0×106m3/s;(5) the average heat transports through Sections PN and TK are 1.99×1015 and 1.78×1015W, respectively and(6) at the computation area, heat transfer is from the ocean to the atmosphere in autumn and winter, but the direction reverses in summer, and the direction of heat transfer is uncertain in spring. The average rate of heat transfer is the largest in winter, but smaller in spring and summer.
A two-layer simple baroclinic ocean model and its simulations of ocean currents in winter and summer
1999, 21(3): 30-39.
Abstract:
A two-layer simple baroclinic ocean model is developed (H1=501,H1+H2=250m). The capabilities of this model are tested by the use of multiyearly averaged January and July sea surface air temperature fields, sea level pressure fields and wind fields which can be diagnosed from the pressure fields. The results show that the simulated ocean surface currents and in undercurrents the second layer in winter and summer are close to the observation.
A two-layer simple baroclinic ocean model is developed (H1=501,H1+H2=250m). The capabilities of this model are tested by the use of multiyearly averaged January and July sea surface air temperature fields, sea level pressure fields and wind fields which can be diagnosed from the pressure fields. The results show that the simulated ocean surface currents and in undercurrents the second layer in winter and summer are close to the observation.
1999, 21(3): 40-50.
Abstract:
The current field was calculated on the basis of the coupling model of a two-layer, reduced gravity primitive equation and the climatic average wind field. The result correctly shows space distribution and season variety of the main current system and thermocline of upper layer in the tropical Pacific. The mixed Rossby-gravity waves were excited by meridional wind stress on 125°W equatorial Pacific. In the climatic condition, the equatorial Kelvin wave current model could be transported from the western equatorial Pacific border to the eastern border, but the equatorial Kelvin wave thermocline model was not, because it was prevented by the westward thermocline perturbation which was excited by mixed Rossby-gravity in the central equatorial Pacific.
The current field was calculated on the basis of the coupling model of a two-layer, reduced gravity primitive equation and the climatic average wind field. The result correctly shows space distribution and season variety of the main current system and thermocline of upper layer in the tropical Pacific. The mixed Rossby-gravity waves were excited by meridional wind stress on 125°W equatorial Pacific. In the climatic condition, the equatorial Kelvin wave current model could be transported from the western equatorial Pacific border to the eastern border, but the equatorial Kelvin wave thermocline model was not, because it was prevented by the westward thermocline perturbation which was excited by mixed Rossby-gravity in the central equatorial Pacific.
1999, 21(3): 51-58.
Abstract:
Based on the remote sensing information feature of Nansha coral islets and reefs that controlled by the Nansha Islands local area's geological structure and growth law, by means of mathematical model and PC, the Nansha Islands coral islets end reefs' top geological data' spatial distribution end local change trend are simulated by using the trend surface system on the remote sensing composite information, and a scientific interpretation and local comparison of Nansha coral islands and islets' spatial distribution feature are made.
Based on the remote sensing information feature of Nansha coral islets and reefs that controlled by the Nansha Islands local area's geological structure and growth law, by means of mathematical model and PC, the Nansha Islands coral islets end reefs' top geological data' spatial distribution end local change trend are simulated by using the trend surface system on the remote sensing composite information, and a scientific interpretation and local comparison of Nansha coral islands and islets' spatial distribution feature are made.
1999, 21(3): 59-65.
Abstract:
Photosynthetic rates(PR) of four species of marine single-celled algae were determined by means of 14C-tracer method under the experimental modeling conditions. The effects of environmental factors, such as light, temperature and nutrients, on the biochemical compositions of the algae were studied. The results indicate that the suitable light intensities for the growth of Phaeodactylum tricornutum, Dunaliella spp.,Skeletonema costatum and Isochrysis galbana are in the range 5.8×103 to 15×103lx, showing an increasing trend of PR with the heightened light intensities. The irradiance response of Dunaliella spp. and Isochrysis galbana is significant. The contents of carbohydrate increase, but those of protein decrease, otherwise, the contents of lipids changed little. The optimum temperatures for the growth of the four species of algae are 14, 26, 21 and 26℃ respectively, characterized by the maxima of PR and the contents of carbohydrate, protein and lipids as well as their variations. The apparent activation energies in the photosynthesis process of Phaeodactylum tricornutum, Dunaliella spp.,Skeletonema costatum and Isochrysis galbana are 23.2, 38.5, 22.4 and 61.7 kj/mol respectively, and the temperature coefficients for the four algae are 1.74, 1.74, 1.38 and 1.69 respectively. The peaks of PR appeared in some culture media(N/P=16) of Phaeodactylum tricornutum and Skeletonema costatum,while in other media(N/P=28) of Dunaliella spp. and Isochrysis galbana.The contents and their variations of carbohydrate, protein and lipids of the four species of algae are all maximum when N/P is equal to 16 in culture media.
Photosynthetic rates(PR) of four species of marine single-celled algae were determined by means of 14C-tracer method under the experimental modeling conditions. The effects of environmental factors, such as light, temperature and nutrients, on the biochemical compositions of the algae were studied. The results indicate that the suitable light intensities for the growth of Phaeodactylum tricornutum, Dunaliella spp.,Skeletonema costatum and Isochrysis galbana are in the range 5.8×103 to 15×103lx, showing an increasing trend of PR with the heightened light intensities. The irradiance response of Dunaliella spp. and Isochrysis galbana is significant. The contents of carbohydrate increase, but those of protein decrease, otherwise, the contents of lipids changed little. The optimum temperatures for the growth of the four species of algae are 14, 26, 21 and 26℃ respectively, characterized by the maxima of PR and the contents of carbohydrate, protein and lipids as well as their variations. The apparent activation energies in the photosynthesis process of Phaeodactylum tricornutum, Dunaliella spp.,Skeletonema costatum and Isochrysis galbana are 23.2, 38.5, 22.4 and 61.7 kj/mol respectively, and the temperature coefficients for the four algae are 1.74, 1.74, 1.38 and 1.69 respectively. The peaks of PR appeared in some culture media(N/P=16) of Phaeodactylum tricornutum and Skeletonema costatum,while in other media(N/P=28) of Dunaliella spp. and Isochrysis galbana.The contents and their variations of carbohydrate, protein and lipids of the four species of algae are all maximum when N/P is equal to 16 in culture media.
1999, 21(3): 66-72.
Abstract:
Four type of in-water fluorometers were successfuly developed by authors in the past few years and applied widely to marine and river water mixing experiment; large or middle water area environment evaluation; trace oil in water and in situ marine phytoplankton chlorophyl a concentration measurment. In the dumping area of water in the Huanghai Sea and the East China Sea, we used the towing fluorometes are used, changing its fluorescence filter with neutral filter, for deep tracking measurment of suspended dumping material (coal ash, powder and alkali residue).It is first experiment in home and the experimeat results are satisfactory also. Fluorometry principle, advantage and underwater floor-ometer construction are described. Today, fluorimetry measuring in water material is a simple, quick, high sensitive and wide applicable measurment technique. It will plays the very important role in marine measurement in future.
Four type of in-water fluorometers were successfuly developed by authors in the past few years and applied widely to marine and river water mixing experiment; large or middle water area environment evaluation; trace oil in water and in situ marine phytoplankton chlorophyl a concentration measurment. In the dumping area of water in the Huanghai Sea and the East China Sea, we used the towing fluorometes are used, changing its fluorescence filter with neutral filter, for deep tracking measurment of suspended dumping material (coal ash, powder and alkali residue).It is first experiment in home and the experimeat results are satisfactory also. Fluorometry principle, advantage and underwater floor-ometer construction are described. Today, fluorimetry measuring in water material is a simple, quick, high sensitive and wide applicable measurment technique. It will plays the very important role in marine measurement in future.
Preliminary study on the role of tidal currents in the filling of the paleo-Changjiang River Estuary
1999, 21(3): 73-82.
Abstract:
The Changjiang River Delta was formed through the filling of the paleo-Chartgjiang River Estuary(PORE).The study on the role of tide and tidal currents in the filling of the PCRE can help to understand the development of the Changjiang River Delta better. With a 2-D tide model, the MZ tide and tidal currents in the Bohai Sea, Huanghai Sea and East China Sea at the postglacial marine transgression maximum are simulated. Based on the hydrodynamic data obtained, the sediment transport fields of 8 kinds of grain size in the PCRE and its adjoining areas are calculated, and the seabed erosion-accretion pattern is obtained in terms of the divergence of sediment transport rate. The results show that at the post-glacial transgression maximum, there existed a noticeable wave loop of standing tidal waves with the antinode of the wave loop being located in the mouth of the PCRE, and the wave loop lines being protruded towards sea. Under its control, tidal currents converge to or diverge from the mouth of the PORE. Within a single tidal cycle, net sediment was directed towards the PCRE. Thus the PCRE has been filled under the conditions that the Changjiang River supplies a large amount of sediment, and the tide and tidal currents in the open sea impel this sediment to deposit as much as possible in the PCRE. The tide and tidal currents in the open sea provide necessary and favorable dynamic environment for the filling of the PCRE and the development of the Changjiang River Delta.
The Changjiang River Delta was formed through the filling of the paleo-Chartgjiang River Estuary(PORE).The study on the role of tide and tidal currents in the filling of the PCRE can help to understand the development of the Changjiang River Delta better. With a 2-D tide model, the MZ tide and tidal currents in the Bohai Sea, Huanghai Sea and East China Sea at the postglacial marine transgression maximum are simulated. Based on the hydrodynamic data obtained, the sediment transport fields of 8 kinds of grain size in the PCRE and its adjoining areas are calculated, and the seabed erosion-accretion pattern is obtained in terms of the divergence of sediment transport rate. The results show that at the post-glacial transgression maximum, there existed a noticeable wave loop of standing tidal waves with the antinode of the wave loop being located in the mouth of the PCRE, and the wave loop lines being protruded towards sea. Under its control, tidal currents converge to or diverge from the mouth of the PORE. Within a single tidal cycle, net sediment was directed towards the PCRE. Thus the PCRE has been filled under the conditions that the Changjiang River supplies a large amount of sediment, and the tide and tidal currents in the open sea impel this sediment to deposit as much as possible in the PCRE. The tide and tidal currents in the open sea provide necessary and favorable dynamic environment for the filling of the PCRE and the development of the Changjiang River Delta.
1999, 21(3): 83-89.
Abstract:
There were at least three transgressions and three corresponding marine strata were left during Late Pleistocene in the shelf region of nearshore seas of China. In the regression during the last ice-age, the main feature of sedimentary environment in continental shelf region of nearshore seas of China were cold and dry. Wind-action was a major exogenetic force not only on land but also on the shelf region. The shelf area is partly desertized and desert deposits and their derivative sediments(loess deposits) were held. Based on the records of shallow layer profiler with total length of several thousand kilometres, it is found out that marine strata since Late Pleistocene were not preserved without disturbation. Under the intensive wind effect, the original sediment structure on the exposed shelf changed partly and formed new sedimentary type. So the disintegration of integrated marine stratum occurred in the shelf region of nearshore seas of China.
There were at least three transgressions and three corresponding marine strata were left during Late Pleistocene in the shelf region of nearshore seas of China. In the regression during the last ice-age, the main feature of sedimentary environment in continental shelf region of nearshore seas of China were cold and dry. Wind-action was a major exogenetic force not only on land but also on the shelf region. The shelf area is partly desertized and desert deposits and their derivative sediments(loess deposits) were held. Based on the records of shallow layer profiler with total length of several thousand kilometres, it is found out that marine strata since Late Pleistocene were not preserved without disturbation. Under the intensive wind effect, the original sediment structure on the exposed shelf changed partly and formed new sedimentary type. So the disintegration of integrated marine stratum occurred in the shelf region of nearshore seas of China.
1999, 21(3): 90-97.
Abstract:
Based on the features of gully landform on the subaqueous delta near old Huanghe River mouth, a dynamical method to analyse mechanism for the growth of gully was used. It is shown that wave-induced near bed current is the dominant factor which leads to growth of gully. Secondary current caused by turbulent fluctuation in the gully makes velocity field very complicated. And boundary shear stress caused by them has an important effect on erosion of gully, and suspension and dispersion of sediment. The pattern of gully's lateral profile is related intimatey to the velocity field of main and secondary current.
Based on the features of gully landform on the subaqueous delta near old Huanghe River mouth, a dynamical method to analyse mechanism for the growth of gully was used. It is shown that wave-induced near bed current is the dominant factor which leads to growth of gully. Secondary current caused by turbulent fluctuation in the gully makes velocity field very complicated. And boundary shear stress caused by them has an important effect on erosion of gully, and suspension and dispersion of sediment. The pattern of gully's lateral profile is related intimatey to the velocity field of main and secondary current.
1999, 21(3): 98-105.
Abstract:
The observations on standing crop and productivity of the benthic microflora living on tidal flats of the Xiangshan Bay, Zhejiang have been carried out in 1992. Four tonal representative transects on the flats, i. e.,(a) Dajiahe(near apex of the bay),(b) Xihugang(in the middle-southern bay),(c) Hutoudu(in the middle-northern bay) and(d) Hengshan(near the bay mouth), were selected in the observations during May and 7une, and the additionally seasonal observations(in February, August and October) at Hutoudu tidal flat transect were also conducted. The results obtained show that there are pronounced spatial and seasonal variations of chlorophyll a concentrations at the surface of the tidal flats, i. e.,the concentrations are higher at near apex than at the middle and near the mouth of the bay, and those are higher in May [(10. 36±8.08)μg/g] than in June [(2.94±1.21)μg/g]. The chlorophyll a concentrations at the surface of the sediments are high, and rapidly decrease with the depth, due to the light limiration, but the concentrations of phaeopigments increase. The average primary productivity of the benthic microflora is(561±385) mg/(m2·d)(C) in May and(535±171 μg) /(m2·d)(C) in 7une, which is higher than the average productivity of phytoplankton in the water column. On the tidal flats of Hutoudu, the highest chlorophyll a concentration occurred in August [(15. 26±19.08)μg/g], the lowest in February(4.24 μg/g), and the primary productivity was the highest in August[(2584±2431)mg/(m2·d)(C)] and the lowest in October [(181±179)mg/(m2·d)(C)].
The observations on standing crop and productivity of the benthic microflora living on tidal flats of the Xiangshan Bay, Zhejiang have been carried out in 1992. Four tonal representative transects on the flats, i. e.,(a) Dajiahe(near apex of the bay),(b) Xihugang(in the middle-southern bay),(c) Hutoudu(in the middle-northern bay) and(d) Hengshan(near the bay mouth), were selected in the observations during May and 7une, and the additionally seasonal observations(in February, August and October) at Hutoudu tidal flat transect were also conducted. The results obtained show that there are pronounced spatial and seasonal variations of chlorophyll a concentrations at the surface of the tidal flats, i. e.,the concentrations are higher at near apex than at the middle and near the mouth of the bay, and those are higher in May [(10. 36±8.08)μg/g] than in June [(2.94±1.21)μg/g]. The chlorophyll a concentrations at the surface of the sediments are high, and rapidly decrease with the depth, due to the light limiration, but the concentrations of phaeopigments increase. The average primary productivity of the benthic microflora is(561±385) mg/(m2·d)(C) in May and(535±171 μg) /(m2·d)(C) in 7une, which is higher than the average productivity of phytoplankton in the water column. On the tidal flats of Hutoudu, the highest chlorophyll a concentration occurred in August [(15. 26±19.08)μg/g], the lowest in February(4.24 μg/g), and the primary productivity was the highest in August[(2584±2431)mg/(m2·d)(C)] and the lowest in October [(181±179)mg/(m2·d)(C)].
1999, 21(3): 106-112.
Abstract:
The rDNA internal transcribed spacer and 5.8s regions of 7 strains of Alexandrium "tamarense complex" were amplified with the method of PCR amplification with individual cells for RFLP analysis and sequensing. PCR-RFLP analysis of rDNA ITS using three restriction enzymes revealed 7 strains carried unique restriction patterns and were in common with those of Japanese A.catenella.The sequence comparisons of three strains(ADOl, AHOl, ANO1) with the homologous sequences of Japanese A. catenella and A.tamarense determined by Masao Adachi et al.in 1996 showed that three strains from the South China Sea with those Japanese A.catenella were closely related to each other, distance values between strains were extremely low(<0.01), whereas distance values between three strains and Japanese A.tamarense were high(about 0.20), which suggested that 7 strains from the South China Sea were the species of A.catenella.It was concluded that rDNA ITS region could served as criteria for the "red tide" species identification.
1999, 21(3): 113-118.
Abstract:
Detailed ultrastructural pathology of Rickettsia-like organism(RLO) disease which is extensively prevalent in maricutured pearl oyster, Pinctada maxima and P. fucata, was described. The RLO disease, at the ultrastructural level, presented a process from degeneration to necrosis of cellular organelles such as the nucleus underwent pyknosis, karyorrhexis and karyolysis; mitochondria and endoplasmic reticulums presented a series of clody swellings and vacuolar degenerations; at last, these cellular organelles were lysis and the cytoplasm become loose and disappeared. Combined with the results of previous histological pathology observed by light and present ultrastructural pathology observed by transmission electron microscope, there may be three mechanisms on the pathogenesis for the pearl oyster hosts causing by parasitizing RLO:(i) damaging cell membrane of host by large quantities of multiplications of RLO;(ii) interfering with normal metabolisms of host cell by growth and multiplication of RLO;(iii) causing nutrient and respiratory metabolic disorders as a result of compromising the small blood vessels by parasitizing RLO in endothelial cells or/and associating with releasing endotoxin of RLO for the extensive lesion of hepatopancreas.
Detailed ultrastructural pathology of Rickettsia-like organism(RLO) disease which is extensively prevalent in maricutured pearl oyster, Pinctada maxima and P. fucata, was described. The RLO disease, at the ultrastructural level, presented a process from degeneration to necrosis of cellular organelles such as the nucleus underwent pyknosis, karyorrhexis and karyolysis; mitochondria and endoplasmic reticulums presented a series of clody swellings and vacuolar degenerations; at last, these cellular organelles were lysis and the cytoplasm become loose and disappeared. Combined with the results of previous histological pathology observed by light and present ultrastructural pathology observed by transmission electron microscope, there may be three mechanisms on the pathogenesis for the pearl oyster hosts causing by parasitizing RLO:(i) damaging cell membrane of host by large quantities of multiplications of RLO;(ii) interfering with normal metabolisms of host cell by growth and multiplication of RLO;(iii) causing nutrient and respiratory metabolic disorders as a result of compromising the small blood vessels by parasitizing RLO in endothelial cells or/and associating with releasing endotoxin of RLO for the extensive lesion of hepatopancreas.
1999, 21(3): 119-125.
Abstract:
Based on numerical simulation and observation data, the four estimating methods of directional spectrum, maximum-likelihood method(MLM), extended eigenvector method(EEV), extended maximum-entropy principle(EMEP) and Bayesian directional method(BDM) are studied about their reliabilities respectively. It is shown that MLM, EEV and BDM basically give the same directional distribution in general. However, BDM holds the best reproducibility in any cases, and is inferior to MLM and EEV in practicality. EMEP is not suitable to real observation data because of its poor stability.
Based on numerical simulation and observation data, the four estimating methods of directional spectrum, maximum-likelihood method(MLM), extended eigenvector method(EEV), extended maximum-entropy principle(EMEP) and Bayesian directional method(BDM) are studied about their reliabilities respectively. It is shown that MLM, EEV and BDM basically give the same directional distribution in general. However, BDM holds the best reproducibility in any cases, and is inferior to MLM and EEV in practicality. EMEP is not suitable to real observation data because of its poor stability.
1999, 21(3): 126-133.
Abstract:
A kind of multi-function concrete platform suitable for offshore marginal oil fields is presented. Style selection and structrue optimum of the platform ate finished. The effects of the constraint conditions on the cost of the platform are analysed. The application conditions of the platform are given. The method of analysis constrains monotonicity and auto-giving the initial value is used in optimum. The initial metacentric height is given with fuzzy theory to consider the subjective information.
A kind of multi-function concrete platform suitable for offshore marginal oil fields is presented. Style selection and structrue optimum of the platform ate finished. The effects of the constraint conditions on the cost of the platform are analysed. The application conditions of the platform are given. The method of analysis constrains monotonicity and auto-giving the initial value is used in optimum. The initial metacentric height is given with fuzzy theory to consider the subjective information.
1999, 21(3): 141-144.
Abstract:
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