Averaged sound intensity in shallow water having a negative leap-layer and a constant depth

The leap-layer is assumed to consist of two isovelocity water layers. The expressions of the law on the decay of the averaged sound intensity with range are derived when the source and receiver are laid in the same isovelocity water layer or in two different isovelocity water layers respectively. The results show that there is apparent depth constitution in the sound field in the leap-layer. The theoretical results agree quite well with the practical data. This paper was published in Chinese inOceanologia et Limnologia Sinica 15(6): 550–557, 1984.     

Chemical constituents of marine medicinal mangrove plant <Emphasis Type="Italic">Sonneratia caseolaris</Emphasis>

Twenty-four compounds including eight steroids (1–8), nine triterpenoids (9–16, 24), three flavonoids (20–22), and four benzenecarboxylic derivatives (17–19, 23) were isolated and identified from stems and twigs of medicinal mangrove plant Sonneratia caseolaris. The structures of the isolated compounds were determined by extensive analysis of their spectroscopic data. Among these metabolites, compounds 1, 4–20 and 22–24 were isolated and identified for the first time from S. caseolaris. In the in vitro cytotoxic assay against SMMC-7721 human hepatoma cells, compound 21 (3′,4′,5,7-tetrahydroxyflavone) exhibited significant activity with IC₅₀ 2.8 μg/mL, while oleanolic acid (14), 3,3′-di-O-methyl ether ellagic acid (18), and 3,3′,4-O-tri-O-methyl ether ellagic acid (19) showed weak activity. None of these compounds displayed significant antibacterial activites. Supported by the National Natural Science Foundation of China (No. 30770234); Knowledge Innovation Program of Chinese Academy of Sciences (KZCX2-YW-211-04); Department of Science and Technology of Shandong Province (No.2006GG2205023)     

Discussion of some conceptions of a water mass based on the theory of fuzzy sets

The fundamental principle for differentiating water masses is a strict consideration of their “relative interier homogeneity” and obvious exterior differences with others in characteristics. The conceptions of water type, water mass and water system are dealt with on the basis of the theory of fuzzy sets. A proposal to apply the theory of fuzzy sets to define the water mass and its core, independent area, boundary and mixing area is put forward. As an example, the membership function of the surface water masses in the Yellow Sea and East China Sea in August, 1979, are considered. Their cores, independent areas, boundaries, mixing areas and the approximation degrees between different water masses are calculated respectively. The water masses are ranged according to their fuzzy degrees. This paper was published inOceanologia et Limnologia Sinica, 1986,17(2): 102–110. This study was financially supported by National Natural Sciences Foundation of China.     

The antitumor effect of bromophenol derivatives <Emphasis Type="Italic">in vitro</Emphasis> and <Emphasis Type="Italic">Leathesia nana</Emphasis> extract <Emphasis Type="Italic">in vivo</Emphasis>

To investigate the antitumor effect of bromophenol derivatives in vitro and Leathesia nana extract in vivo, six bromophenol derivatives 6-(2,3-dibromo-4,5-dihydroxybenzyl)-2,3-dibromo-4,5-dihydroxy benzyl methyl ether (1), (+)-3-(2,3-dibromo-4,5-dihydroxyphenyl)-4-bromo-5,6-dihydroxy-1,3-dihydroisobenzofuran (2), 3-bromo-4-(2,3-dibromo-4,5-dihydroxybenzyl)-5-methoxymethyl-pyrocatechol (3), 2,2′,3,3′-tetrabromo-4,4′,5,5′-tetrahydroxy-diphenylmethane (4), bis(2,3-dibromo-4,5-dihydroxybenzyl) ether (5), 2,2′,3-tribromo-3′,4,4′,5-tetrahydroxy-6′-ethyloxymethyldiphenylmethane (6) were isolated from brown alga Leathesia nana, and their cytotoxicity were tested by MTT assays in human cancer cell lines A549, BGC-823, MCF-7, B16-BL6, HT-1080, A2780, Bel7402 and HCT-8. Their inhibitory activity against protein tyrosine kinase (PTK) with over-expression of c-kit was analyzed also by ELISA. The antitumor activity of ethanolic extraction of Leathesia nana (EELN) was evaluated on S₁₈₀-bearing mice. All compounds showed very potent cytotoxicity against all of the eight cancer cell lines with IC₅₀ below 10 μg/mL. In PTK inhibition study, all bromophenol derivatives showed moderate inhibitory activity and compounds 2, 5 and 6 showed significant bioactivity with the inhibition ratio of 77.5%, 80.1% and 71.4%, respectively. Pharmacological studies reveal that EELN could inhibit the growth of Sarcoma 180 tumor and increase the indices of thymus and spleen to improve the immune system remarkably in vivo. Results indicated that the bromophenol derivatives and EELN can be used as potent antitumor agents for PTK over-expression of c-kit and considered in a new therapeutic strategy for treatment of cancer. Supported by the National High Technology Research and Development Program of China (863 Program, No. 2007AA09Z410) and Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX2-YW-209)     

Studies on the eggs and larvae,ofSardinella aurita (Cuv. & Val.) in the fishing grounds of Southern Fujian and the Taiwan Bank

In this paper, the morphological characters of eggs and larvae ofSardinella aurita (Cuvier & Valenciennes), its spawning ground, spawning seasons and spawning conditions have been studied. Sardinella aurita likes to breed in the upwelling area and selects the Waixie fishing ground as its main spawning ground. The months from February to September are its spawning seasons, reaching its peak in April. In the main spawning ground, the temperature of the surface layer was found to be 24.4–25.2°C, the salinity 33.87–34.07%. and the depth of water between 34–60m. The distribution of the larvae is closely related to the distribution of plankton, the path of migration of adult fish, and the current direction of the water system. In order to protect fishery resources, it is necessary to prohibit catching the spawning fish in the Waixie fishing ground in April, and the catching of immatures from March to June. This paper was published in Chinese inOcean. Limn. Sinica 14(3): 240–248, 1983.     

Synthesis and protein tyrosine phosphatase 1B inhibition activities of two new synthetic bromophenols and their methoxy derivatives

3-bromo-4,5-bis(2,3-dibromo-4,5-dihydroxybenzyl)-1,2-benzenediol (1) is a natural bromophenol isolated from the red algae Rhodomela confervoides that exhibits significant inhibition against protein tyrosine phosphatase 1B (PTP1B). Based on its activity, we synthesized two new synthetic bromophenols and their methoxy derivatives from vanillin using the structure of natural bromophenol 1 as a scaffold. The structures of these bromophenols were elucidated from 1H NMR, 13C NMR, and high resolution electron ionization mass spectrometry as 2,3-dibromo-1-(2p-bromo-6p-(3q,4q-dimethoxybenzyl)- 3p,4p-dimethoxybenzyl)-4,5-dimethoxybenzene(2),2,3-dibromo-1-(2p-bromo-6p-(2q-bromo-4q,5q-dimethoxy-benzyl)-3p,4p-dimethoxybenzyl)-4,5-dimethoxybenzene(3),3,4-dibromo-5-(2p-bromo-6p-(2q-bromo-4q,5q-dihydroxybenzyl)-3p,4p-dihydroxybenzyl)pyrocatechol(4)and 3,4-dibromo-5-(2p-bromo-6p-(3q,4q-dihydroxybenzyl)-3p,4p-dihydroxybenzyl)pyrocatechol (5).PTP1B inhibition activities of these compounds were evaluated using a colorimetric assay,and compounds 3 and 4 demonstrated interesting activity against PTP1B.     

EFFECT OF WATER DEPTH ON WIND-WAVE FREQUENCY SPECTRUM Ⅰ.SPECTRAL FORM

Wen et al.'s odhed dewiogh to obtain wind-wave frequency spectrum in deep was used toderive the spectrum in finite depth water. The spedrum S(ω) (ω bein angular frequency) when normalizedwith the zeroth moment m and peak frequercyω。 contains in adrition to the peakness factor P=ω。S(ω。)/m。, a twth parameter n=(2πm。)_(1/2)d (d being water depPth), so the spatrum behavior can bestudies for different ware growth stages and water depths.     

Synthesis of three bromophenols from red algae as PTP1B inhibitors

Bromophenols are a set of natural products widely distributed in seaweed, most of which exhibit interesting and useful biological activities. To develop a reliable and efficient synthetic route to these natural bromophenols, three of them, 3,4-dibromo-5-(2′-bromo-3′,4′-dihydroxy-6′-methoxymethyl-benzyl)-benzene-1,2-diol (compound 9), 3,4-dibromo-5-(2′-bromo-6′-ethoxy methyl-3′,4′-dihydroxybenzyl)-benzene-1,2-diol (compound 10), and 3-bromo-4-(3′-bromo-4′,5′-dihydroxy benzyl)-5-(ethoxymethyl)-benzene-1,2-diol (compound 14), isolated from red marine algae, have been synthesized in eight steps with an overall yield of 14.4%, 14.4%, and 18.2% respectively, via a practical approach employing bromination, Wolff-Kishner-Huang reduction and a Friedel-Crafts reaction as key steps. The protein tyrosine phosphatase 1B (PTP1B) inhibitory activities of the synthetic compounds were evaluated by the colorimetric assay. The results show that these compounds are moderate PTP1B inhibitors. The synthesis of these bromophenol derivatives makes in vivo studies of their structure-activity relationships and inhibition activity against PTP1B possible.     

Structural Changes and Rheological Properties of Dry Abalone Meat （Haliotis diversicolor） During the Process of Water Restoration

Changes in tissue structure, rheological property and water content of dry abalone meat in the process of water restora- tion were studied. The weight and volume of dry abalone meat increased with water restoration. When observed under a light micro- scope, structural change in myofibrils was obvious and a distinct network was found. When water restoration time increased from 24 h to 72 h, the instantaneous modulus E0 and viscosity η1 increased, whereas the rupture strength and relaxation time (τ1) were re- duced. There were no significant changes of rheological parameters (E0, η1, τ1, rupture strength) from 72 h to 96 h of water restoration. Therefore, the dry abalone meat was swollen enough at the time of 72 h. The rheological parameters were obviously influenced by the structural changes.     

Dynamic model for oil slick dispersion into a water column—A wind-driven wave tank experiment

A dynamic experiment for oil dispersion into a water column was performed with a 21 m long, 0.5 m wide, and 1 m high wind-driven wave tank. At wind velocity between 6–12 m/s and with the oil slick kept constant (about 1 μm), the rate of the oil content increase in the water column could be approximated from the difference between the dispersion rate (R) of the oil slick and the coagulation rate (R′) of the dispersed oil slick. Assuming the coagulation rate is directly proportional to the concentration of the water dispersed oil slick (i. e.R′-K ^*C), the integral form of the dynamic model can be expressed asC=R ^* [1−exp(−K ^*t)]/K and parametersR andK can be regressed with a computer. The relative deviation of model results from the experimental data was mainly less than 10%. The oil slick dispersion rate (R) had exponential relationship with the wind velocity (U), and can be fitted with a formulaR=A ^* (U+1) ^B . The fitted constant of the coagulation rate,K(0.8–3.0^* 10⁻³ min⁻¹) did not have significant relationship with the wind velocity.     

A new ketosteroid from red alga Acanthophora spicifera

A new ketosteroid, along with six known steroids, was isolated from the ethanolic extracts of red alga Acanthophora spicifera (Vahl.) Boergesen. The structures, identified using chemical and spectroscopic methods including 2D NMR, were: (1) 22-hydroxy-5α-cholest-3,6-dione, (2) 6-hydroxycholest-4-ene-3-one, (3) cholest-4-ene-3,6-dione, (4) cholest-5-ene-3β-ol, (5) 5α-cholestane-3,6-dione, (6) β-Sitosterol and (7) Saringosterol. The MTT method was used to test the cytotoxicity of the compounds against the human cancer cell lines, HCT-8, Bel-7402, BGC-823, A549 and HELA. Compounds 1, 2, 3 and 5 showed moderate cytotoxic activity against human cancer cell lines.     

The Antitumor Components from Marine-derived Bacterium Streptoverticillium luteoverticillatum 11014 Ⅱ

Eight known compounds were isolated from a marine-derived bacterium Streptoverticillium luteoverticillatum 11014 using bioassay-guided fractionations. Their structures were identified by spectral analysis as bis （4-hydroxybenzyl） ether （1）, p-hydroxyphenylethyl alcohol （2）, N-（4-hydroxyphenethyl） acetamide （3）, indole-3 carboxylic acid methyl ester （4）, dibenzo[b,e] [1,4]dioxine （5）, thymine （6）, cytosine deoxyribonucleoside （7） and 2, 3-butanediol （8）. These compounds were evaluated for their cytotoxic activities against K562 cell line with the SRB method for the first time. Compounds 2 and 4 showed cytotoxcities with IC50 values of 101.1 and 165.3 μolL^-1, respectively. All compounds were isolated from S. luteoverticillatum 11014 for the first time.     

A study on the flux,speciation, and budget of mercury in controlled experimental ecosystems

The lowest addition of mercury (0.1 ug Hg 1⁻¹) was used in CEEs for research on mercury flux, speciation and budget. The removal behavior of mercury by phytoplankton in water columns of CEEs can be described by first order kinetic equations for total and particulate mercury in the CEE spiked by mercury. The removal rate of mercury in water columns depends on the size and productivity of phytoplanton in a water column to which mercuric ions were added. A 4.4 day half-life time and a 2.8 day half-life time for total and particulate mercury respectively was obtained in diatom bloom. During microflagellate bloom a 30 day total mercury half-life time was estimated with increase of particulate mercury in the water column. The 0.010 ug Hg cm⁻²y⁻¹ mercury flux rate that was attained in the control bag agreed with the values from field measurements in Saanich Inlet where the bags were launched. The proportion of total mercury to dissolved and particulate mercury depended also on the size, productivity, and concentration of mercury in a water column. A more or less constant distribution of mercury species in the control bag was observed as follows: dissolved Hg 0.73, particulate Hg 0.27, inorganic Hg 0.42, dissolved organic Hg 0.31. After spiking with mercury, the particulate mercury rose rapidly and reached to over 70% of the total mercury. The concentration factor of mercury by phytoplankton in the CEEs in the order of 10⁵ was consistent with the results from field measurements in Saanich Inlet. The mercury recovery from the water column, sediment, water with sediment, and the CEE bag walls was only 52.3% of total mercury spiked in the CEE. The losses of mercury by vaporization into the ambient air and diffusion through the wall of the enclosure should be considered. This paper was published in Chinese inOcean. Limn. Sinica,17(4):307–317, 1986.     

Relationship between heavy metal pollution and water productivity in Xiamen estuarine harbor

This paper is based on the results of simulation experiments and annual observations on the effect of Cr, Cu, Hg, and Zn on diatom (Chaetoceros sp.Skeletonema costatum andMelosira sulcata) growth. Laboratory experiments reveal many physico-chemical parameters play an important role in the toxicity and accumulation of metals in organisms. The mesotrophic level in the water environment is related to phytoplankton growth. A higher nutrient level can have a negative impact on diatom production. Several of the above metals coexist in the investigated region and exert mainly a negative effect on growth. This paper was published in Chinese in theOceanologia et Limnologia Sinica 17(3):173–183, 1986.     

Bioflocculant Produced by Klebsiella sp. MYC and Its Application in the li＇eatment of Oil-field Produced Water

Seventy-nine strains of bioflocculant-producing bacteria were isolated from 3 activated sludge samples. Among them, strain MYC was found to have the highest and stable flocculating rate for both kaolin clay suspension and oil-field produced water. The bacterial strain was identified as Klebsiella sp. MYC according to its morphological and biochemical characteristics and 16SrDNA sequence. The optimal medium for bioflocculant production by this bacterial strain was composed of cane sugar 20 g L^-1, KH2PO4 2 g L^-1, K2HPO4 5 g L^- 1, （ NH4）2SO4 0.2 g L^-1, urea 0.5 g L^- 1 and yeast extract 0.5 g L^- 1, the initial pH being 5.5. When the suspension of kaolin clay was treated with0.5% of Klebsiella sp. MYC culture broth, the flocculating rate reached more than 90.0% in the presence of 500mg L^-1 CaCI2, while the flocculating rate for oil-field produced water was near 80.0% in a pH range of 7.0 - 9.0 with the separation of oil and suspended particles from the oil-field produced water under similar conditions. The environment-friendly nature of the bioflocculant and high flocculating rate of the strain make the bioflocculant produced by Klebsiella sp. MYC an attractive bioflocculant in oil-field produced water treatment.     

Effect of algae and water on water color shift

This study showed that the combined effect of absorption of planktonic algae and water on water color shift can be simulated approximately by the exponential function: Log(E _100cm ^W +E _100cm ^Xch1 )=0.002λ−2.5 whereE _{100 cm} ^W ,E _100cm ^Xchl are, respectively, extinction coefficients of seawater and chlorophyll—a (concentration is equal toX mg/m³), and λ (nm) is wavelength. This empirical regression equation is very useful for forecasting the relation between water color and biomass in water not affected by terrigenous material. The main factor affecting water color shift in the ocean should be the absorption of blue light by planktonic algae.     

Size-fractionated phytoplankton biomass in autumn of the Changjiang （Yangtze） River Estuary and its adjacent waters after the Three Gorges Dam construction

A cruise was undertaken from 3rd to 8th November 2004 in Changjiang （Yangtze） River Estuary and its adjacent waters to investigate the spatial biomass distribution and size composition of phytoplankton. Chlorophyll-a （Chl-a） concentration ranged 0.42-1.17 μg L^-1 and 0.41-10.43 μg L^-1 inside and outside the river mouth, with the mean value 0.73 μg L^-1 and 1.86 μg L^-1, respectively. Compared with the Chl-a concentration in summer of 2004, the mean value was much lower inside, and a little higher outside the river mouth. The maximal Chl-a was 10.43 μg L^-1 at station 18 （122.67°E, 31.25°N）, and the region of high Chl-a concentration was observed in the central survey area between 122.5°E and 123.0°E. In the stations located east of 122.5°E, Chl-a concentration was generally high in the upper layers above 5 m due to water stratification. In the survey area, the average Chl-a in sizes of 〉20 μm and 〈20 μm was 0.28 μg L^-1 and 1.40 μg L^-1, respectively. High Chl-a concentration of 〈20 μm size-fraction indicated that the nanophytoplankton and picophytoplankton contributed the most to the biomass of phytoplankton. Skeletonema costatum, Prorocentrum micans and Scrippsiella trochoidea were the dominant species in surface water. The spatial distribution of cell abundance of phytoplankton was patchy and did not agree well with that of Chl-a, as the cell abundance could not distinguish the differences in shape and size of phytoplankton cells. Nitrate and silicate behaved conservatively, but the former could probably be the limitation factor to algal biomass at offshore stations. The distribution of phosphate scattered considerably, and its relation to the phytoplankton biomass was complicated.     

Influences of wind on vertical structures of temperature and salinity,and upwelling off Zhejiang coast in summer

In this paper the influences of short-term wind on vertical structures of temperature and salinity, and the upwelling off the Zhejiang coast are studied on the basis of hydrographic data and wind near the coast in Summer (1959–1979). It is pointed out that the variations of vertical distributions of temperature and salinity, and upwelling in this region are closely related to short-term (several days to a week) variation of wind observed. The occurrence of double thermocline, a special oceanographic phenomenon, is partially related to unstable SSW wind field. SSW and NE winds in June are two dynamic factors making intermediate warm water form or disappear. Contribution No. 792 from the Institute of Oceanology, Academia Sinica. This paper was published in Chinese inOceanologia et Limnologia Sinica 14 (1): 14–21, 1983.     

The fronts of the Huanghai cold water mass (HCWM) induced by tidal mixing

Since Simpson and Hunter proposed in 1971 the idea that shallow water fronts were induced by tidal mixing, many authors have investigated the tide induced shallow water fronts in various areas. It was generally assumed that a critical value of the stratified parameterK=log₁₀(H/U ³) may be used to identify the location of these fronts. Here, H means the depth of sea waler. U denotes the characteristic velocity of tidal current. and the critical value ofK is generally laken as 1.8–2.0. In this paper. Simpson-Hunter’s stratified parameterK was calculated by using quasi-maximum current velocity (which consists of the six main tidal constituents. i.e.M ₂.S ₂,O ₁.K ₁.M ₄,MS₄) in the H ranghai Sea (Yellow Sea) and in the northern Donghai Sea (East China Sea) as well. Caleulated results show that the areas of the Subei (the northern part of Jiangsu) Shoal. the area off the mouth area of the Changjiang (the Yangtze) River, along the coast of Shandong Peninsula. and along the western coast of Korea, the tidal mixing is strong. Calculations also show that along the whole boundary of the HCWM and also along the western boundary of the cyclonic eddy in the northern Donghai Sea, i.e. along the fronts, the value ofK is found to be very close to the eritical value 1.8. It is also to be noied that at these locations, the temperature of the surface water is very low. These clearly show that shallow water fronts in the Huanghai Sea and in the northern Donghai Sea as well, are induced by tidal mixing. Contribution No. 1241 from Institute of Oceanology, Academia Sinica. This paper was published in Chinese in theOcean. et Limn. Sinica 16(6): 451–459, 1985.     

ON THE BEHAVIORS OF OCEAN BOTTOM EDDY

On the basis of scaling analysis,this paper presents a frontal geostrophic dynamic system which canbe used to describe the dynamics of an isolated bottom eddy and shows that five possible dynamicsubregimes are included in the system.A particle-in-cell method is used to investigate the behavior of the eddy in the two dynamic subregimes,with 1)nonlinear effect(ε)relevant to the sloping bottom-inducedbeta effect(β_1)and 2)seamount-induced beta effect(β_2)dominant.In the dynamic subregime of β_1～ ε～10~(-2)and β_2=0,the eddy can keep as a whole for a long time and migrates for a long distance.Inthe dynamic subregime where the seamount-induced beta effect (β_2～10~(-1))is dominant,the seamounttraps the water particles,causing the eddy to break up into a discrete set of eddies moving around the seamount.