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1.
This article reports studies on the coagulation of kaolin(from Wuxian,Jiangsu,China)on various red tide organisms,and the observation for the first time that the coagulation of kaolin is much greaterthan that of montmorillonite so that kaolin is a more effective clay for removing red tide organisms.The authors’theoretical explanation and analysis by a mathematical-physical model prove that comparedto montmorillonite,kaolin has greater attraction for organism cells and therefore greater coagulation capabil-ity.This project’s studies on the effects of pH and acid-treatment show that the acid-treatment does not have much influence on the kaolin system;whereas the effect of pH on the kaolin system is the same asthat on the montmonrillonite system.  相似文献   

2.
Coagulation of red tide organism cells with clays is discussed in theory and the effects of some fac-tors on it are studied.A quantitative model is presented which describes how the coagulation varies withpH in solution.According to the model,within the pH-range between pH_(zpc_a)and pH_(zpc_b),V_R is negativeand the coagulation is strong and strongest at pH=(pH_(zpc_a)+pH_(zpc_b))/2.It is also demonstrated that whenthe diameter of clay particles is close to that of cells,the collision probability is low,resulting in weakercoagulation.The model results have been corroborated by experiments and so are scientific and theoreticalbases for application.  相似文献   

3.
The present paper reports on comparative studies of R-phycoerythrin (R-PE) from 30 species of the red seaweeds in Bangiophyceae and in Florideophyceae from Qingdao. The measured absorption spectra show that R-PE from these red seaweeds have two spectral types, namely type I having two absorption peaks and type II having three absorption peaks. 9 specise of a lower red seaweed belonging to Bangiophyceae are all type I R-PE. 3 species of a higher red seaweed belonging to Florideophyceae are also type I R-PE. The remaining 18 species are all type II R-PE. According to the distribution of two types of R-PE in red algae, an evolutionary trend from type I R-PE to type II R-PE can be seen, but this evolutionary process is more complicated and without a definite line of demarcation between the two spectral types of R-PE. The occurrence of two types of R-PE in red algae is of taxonomic significance.  相似文献   

4.
The exchange action of six types of organic phenols on clay surfaces in seawater is systematically studied in this work. The following significant conclusions are drawn from the experiments. (1) The interaction of organic phenols with montmorillonite, illite and kaolinite in seawater is monovalent anion exchage.(2) Their isotherms of stepwise exchage on clay surfaces belong to the Langmuir type or stepwise type.(3) The discovery of the"steric hindrance effects of stepwise exchange of organic phenols on clays surfaces", and revelation of an exchange mechanisrn diffeient from that in references are the greatest achieverments in this work.  相似文献   

5.
Clays have considerable influence on the electrical properties of hydrate-bearing sediments.It is desirable to understand the electrical properties of hydrate-bearing clayey sediments and to build hydrate saturation (Sh) models for reservoir evaluation and monitoring.The electrical properties of tetrahydrofuran-hydrate-bearing sediments with montmorillonite are characterized by complex conductivity at frequencies from 0.01 Hz to 1 k Hz.The effects of clay and Sh on the comp...  相似文献   

6.
Two species of jellyfish, Cyanea nozakii Kishinouye and Nemopilema nomurai Kishinouye, have occurred offcoastal areas of the northeastern China Sea, Yellow Sea, and Bohai Sea in recent years. They influence marine ecosystem safety and fishery production, and also pose a risk to human health. The current study examined the hemolytic and cytotoxic activities of crude venoms extracted from the nematocysts of C. nozakii and N. nomurai. The results showed that there were more nematocysts on tentacles from C. nozakii than on tentacles of the same length from N. nomurai. The protein concentration per nematocyst extracted from N. nomurai was higher than that from C. nozakii. Both nematocyst venoms showed dose-and timedependent hemolytic activity on erythrocytes from chicken, pigeon, and sheep, with sheep erythrocytes being the most sensitive, with EC 50 values of 69.69 and 63.62 μg/m L over a 30-min exposure with N. nomurai and C. nozakii nematocyst venoms, respectively. A cytotoxic assay of both jellyfish venoms on A431 human epidermal carcinoma cells resulted in IC 50 values of 68.6 and 40.9 μg/mL after 24-h incubation, respectively, with venom from C. nozakii showing stronger cytotoxic activity than that from N. nomurai. The results of current study indicate that nematocyst venom from C. nozakii had stronger hemolytic and cytotoxic activities than that from N. nomurai and, thus, C. nozakii might be more harmful to the health of humans and other species than are N. nomurai when they appear in coastal waters.  相似文献   

7.
This article reports main results of investigations on red tide in western waters of Xiamen Bay from Jan. to Dec. 1987, and elaborates on the relationship between the change of phytoplanktonic number and main environmental factors there. The cause and the method for judging and monitoring of red tide are discussed.  相似文献   

8.
Muyingle is a new type of health food prepared from marine organisme. The mammotropic action ofMuyingte was investigated by studying its effect on mammary glands and pituitary glands of lactating miceand the survival rate of suckling mice. The results showed that the mammotropic action of Muyingle wasvery effective.The survival rates of suckling mice were 92.90% for the treated group and 0 for the controlgroup (p<0.01). The weights of mammary gland were 163±51.1mg/10g (weight of mouse)for the treatedgroup and 98.5±18.4 mg/10g for the control group (p<0.01). Histological examinations suggestal thatmammary glands from the treated group were at the secreting stages, while those from the control groupwere at the resting stages. Clinical tests also demonstrated that Muyingle was highly effective in promotinglactation and improving the quality of the puerpera's milk. The efficiency was up to 86.7%.  相似文献   

9.
This paper describes 14 species of the family Dentaliidae collected from China by the Institute of Oceanology, Academia Sinica during the surveys on marine invertebrate animals and benthos in the past years. Of which 4 species are considered as new to science; 2 species are first recorded in China. The system adopted is mainly that of T.Habe (1964), but reference is also made to the works of W. Emerson (1962), P. Palmer (1974) and S. D. Chistikov.About 20 Chinese species of Dentaliidae have been described. We consider our study is still not complete and are sure that more species shall be found in further studies.  相似文献   

10.
Male and female adult midges of Pseudosmittia aizaiensis sp. n. are described and illustrated with figures of morphological characters. The inferior volsella of gonocoxite with large lobes, the long but equal width gonostylus. and the small projection in basal part of outer margin are the characters that may separate this species from others. One larva of this genus is purely aquatic in habitat and is associated with Cricotopus bicinctus, Cardiociadius capucinns and Polypedilum sp. in the same algae debris (Spirogyra sp.) of the Dunghe River. Further, the larva's very short SI and SII bifids. its 5 pairs of lateral teeth on mentum and its absence of premandible brush are the characters that may also separate this species from any known species of this genus.  相似文献   

11.
Seasonal variations in numerical abundance, cell diameter and population carbon biomass of the heterotrophic dinoflagellate Noctiluca scintillans were studied for 10 years from 2004 to 2013 in Jiaozhou Bay and adjacent coastal Yellow Sea, China, and their ecological functions were evaluated. In both areas, N. scintillans occurred throughout the year and demonstrated an essentially similar seasonality; the cell abundance increased rapidly from the winter minimum to an annual peak in late spring and early summer, and decreased gradually toward the autumn-winter minimum. The peak abundance differed by years, and there was no consistent trend in long-term numerical variations. The cell diameter also showed a seasonal fluctuation, being larger in spring and early summer than the other seasons. Estimated carbon biomass of N. scintillans population reached to a peak as high as 90.3 mg C/m~3, and occasionally exceed over phytoplankton and copepod biomass. Our results demonstrate that N. scintillans in northwestern Yellow Sea displays the seasonal phenology almost identical to the populations in other temperate regions, and play important trophic roles as a heterotroph to interact with sympatric phytoplankton and copepods.  相似文献   

12.
Fixatives are traditionally used in marine ecosystem research.The bias introduced by fixatives on the dimensions of plankton cells may lead to an overestimation or underestimation of the carbon biomass.To determine the impact of traditional fixatives on dinoflagellates during short-and long-term fixation,we analyzed the degree of change in three bloom-forming dinoflagellates(Prorocentrum micans,Scrippsiella trochoidea and Noctiluca scintillans) brought about by Lugol's iodine solution(hereafter Lugol's) and formalin.The fixation effects were species-specific.P.micans cell volume showed no significant change following long-term preservation,and S.trochoidea swelled by approximately 8.06% in Lugol's and by 20.97% in formalin as a percentage of the live cell volume,respectively.N.scintillans shrank significantly in both fixatives.The volume change due to formalin in N.scintillans was not concentration-dependent,whereas the volume shrinkage of N.scintillans cells fixed with Lugol's at a concentration of 2% was nearly six-fold that in cells fixed with Lugol's at a concentration of 0.6%-0.8%.To better estimate the volume of N.scintillans fixed in formalin at a concentration of 5%,we suggest that the conversion relationship was as follows:volume of live cell=volume of intact fixed cell/0.61.Apart from size change,damage induced by fixatives on N.scintillans was obvious.Lugol's is not a suitable fixative for N.scintillans due to high frequency of broken cells.Accurate carbon biomass estimate of N.scintillans should be performed on live samples.These findings help to improve the estimate of phytoplankton cell volume and carbon biomass in marine ecosystem.  相似文献   

13.
Fractal dimensions of flocs between clay particles and HAB organisms   总被引：1，自引：0，他引：1  
The impact of harmful algal blooms (HABs) on public health and related economics have been increasing in many coastal regions of the world. Sedimentation of algal cells through flocculation with clay particles is a promising strategy for controlling HABs. Previous studies found that removal efficiency (RE) was influenced by many factors, including clay type and concentration, algal growth stage, and physiological aspects of HAB cells. To estimate the effect of morphological characteristics of the aggregates on HAB cell removal, fractal dimensions were measured and the RE of three species of HAB organism, Heterosigma akashiwo, Alexandrium tamarense, and Skeletonema costatum, by original clay and modified clay, was determined. For all HAB species, the modified clay had a higher RE than original clay. For the original clay, the two-dimensional fractal dimension (D2) was 1.92 and three-dimensional fractal dimension (D3) 2.81, while for the modified clay, D2 was 1.84 and D3 was 2.50. The addition of polyaluminum chloride (PACl) lead to a decrease of the repulsive barrier between clay particles, and resulted in lower D2 and D3. Due to the decrease of D3, and the increase of the effective sticking coefficient, the flocculation rate between modified clay particles and HAB organisms increased, and thus resulted in a high RE. The fractal dimensions of flocs differed in HAB species with different cell morphologies. For example, Alexandrium tamarense cells are ellipsoidal, and the D3 and D2 of flocs were the highest, while for Skeletonema costatum, which has filamentous cells, the D3 and D2 of flocs were the lowest.  相似文献   

14.
A new planktonic dinoflagellate, Prorocentrum donghaiense I_a sp. nov., is described in the present paper. The water sample was collected from the Changjiang Estuary, the East China Sea. The species identification is based on shape, size, surface micro-morphology, ornamentation of thecal plates and the architecture of the pel‘iflagellar area and the intercalary bands as seen by fight and scanning electron microscope. Prorocentrum donghaiense Lu sp. nov. is compared with other prorocentrum species with respect to morphological characteristics and bloom behavior. It is not known whether Prorocentrum donghaiense Lu sp. nov produces phycotoxins like some other Prorocentrum species. Four other red tide species in the family Prorocentraceae (Dinophyceae), namely P. balticum, P. minimum, P.micans, P. triestinum, were examined and identified by light and scanning electron microscope. They have been recorded as bloom-forming species. Some aggregates of Prorocentrum are observed at the end of blooms. An event of strong discoloration caused by P. donghaiense could be detected by satellite sensor in the East China Sea in the late spring, of 1995.  相似文献   

15.
The growth, biochemical content and bioaccumulation quantity of 2,2’,4,4’-tetrabromodiphenyl ether （BDE-47） in Skeletonema costatum were studied under different N：P ratios （1, 4, 16, 64 and 128）. All cellular biochemical contents of S. costatum presented decreasing trend over cultivation time. At early stage of cultivation, the cellular protein, carbohydrate and lipid in S. co-statum presented higher values in treatments of N：P=4 and 16. However, they were lower in these treatments at the late stage, but higher in treatments N：P=1 and 128. Similarly, BDE-47 levels per cell of S. costatum were higher in treatments of N：P=4 and 16 at early stage of cultivation, which were 3.8 and 3.7 ng （106 cells）-1, respectively. At the middle stage of cultivation, the BDE-47 level per S. costatum cell lowered;and it further reduced in the treatments of N：P=4 and 16 at the late stage with the values 0.6 and 0.5 ng （106 cells）-1, respectively. However, it rose in N：P=128, reaching up to 2.3 ng （106 cells）-1. Compared with BDE-47 per cell, BDE-47 per algal volume under different N：P ratios did not present obvious difference. The quantity BDE-47 accumulated per cell of S. co-statum was positively correlated with protein, carbohydrate and lipid per cell; meanwhile, the BDE-47 per volume had a positive correlation with biochemical content per volume. The variation of bioaccumulation ability of BDE-47 in S. costatum can be ex-plained by biochemical changes due to N：P ratios.  相似文献   

16.
The characteristics of seasonal variation in phytoplankton biomass and dominant species in the Changjiang River Estuary and adjacent seas were discussed based on field investigation data from 1959 to 2009. The field data from 1981 to 2004 showed that the Chlorophyll-a concentration in surface seawater was between 0.4 and 8.5 μg dm-3. The seasonal changes generally presented a bimodal trend, with the biomass peaks occurring in May and August, and Chlorophyll-a concentration was the lowest in winter. Seasonal biomass changes were mainly controlled by temperature and nutrient levels. From the end of autumn to the next early spring, phytoplankton biomass was mainly influenced by temperature, and in other seasons, nutrient level(including the nutrient supply from the terrestrial runoffs) was the major influence factor. Field investigation data from 1959 to 2009 demonstrated that diatoms were the main phytoplankton in this area, and Skeletonema costatum, Pseudo-nitzschia pungens, Coscinodiscus oculus-iridis, Thalassinoema nitzschioides, Paralia sulcata, Chaetoceros lorenzianus, Chaetoceros curvisetus, and Prorocentrum donghaiense Lu were common dominant species. The seasonal variations in major dominant phytoplankton species presented the following trends: 1) Skeletonema(mainly S. costatum) was dominant throughout the year; and 2) seasonal succession trends were Coscinodiscus(spring) →Chaetoceros(summer and autumn) → Coscinodiscus(winter). The annual dominance of S. costatum was attributed to its environmental eurytopicity and long standing time in surface waters. The seasonal succession of Coscinodiscus and Chaetoceros was associated with the seasonal variation in water stability and nutrient level in this area. On the other hand, long-term field data also indicated obvious interannual variation of phytoplankton biomass and community structure in the Changjiang River Estuary and adjacent seas: average annual phytoplankton biomass and dinoflagellate proportion both presented increased trends during the 1950 s-2000 s.  相似文献   

17.
为提高胺类抑制剂的抑制性和抗温性,优选一种新型两亲性低分子多胺BHTA,设计页岩滚动分散实验、抑制膨润土造浆实验、粒度分布测试评价抑制性能.结果表明:BHTA抑制性优于传统的无机盐类抑制剂KCl和国外聚胺产品Ultrahib,能有效抑制黏土水化膨胀和分散,耐温性优良,可用作泥页岩水化抑制剂.采用Zeta电位测试、红外光谱分析、改性膨润土吸水实验及X线衍射分析测试黏土层间距等,探讨BHTA的作用机理,表明BHTA主要通过质子化胺基与黏土颗粒的静电作用、氢键吸附在黏土表面,以静电吸附为主,通过疏水屏蔽作用发挥抑制作用;BHTA单层吸附进入黏土层间,能最大限度降低黏土水化层间距,破坏黏土水化结构.  相似文献   

18.
Extracting the cell objects of red tide algae is the most important step in the construction of an automatic microscopic image recognition system for harmful algal blooms.This paper describes a set of composite methods for the automatic segmentation of cells of red tide algae from microscopic images.Depending on the existence of setae,we classify the common marine red tide algae into non-setae algae species and Chaetoceros,and design segmentation strategies for these two categories according to their morphological characteristics.In view of the varied forms and fuzzy edges of non-setae algae,we propose a new multi-scale detection algorithm for algal cell regions based on border-correlation,and further combine this with morphological operations and an improved GrabCut algorithm to segment single-cell and multicell objects.In this process,similarity detection is introduced to eliminate the pseudo cellular regions.For Chaetoceros,owing to the weak grayscale information of their setae and the low contrast between the setae and background,we propose a cell extraction method based on a gray surface orientation angle model.This method constructs a gray surface vector model,and executes the gray mapping of the orientation angles.The obtained gray values are then reconstructed and linearly stretched.Finally,appropriate morphological processing is conducted to preserve the orientation information and tiny features of the setae.Experimental results demonstrate that the proposed methods can effectively remove noise and accurately extract both categories of algae cell objects possessing a complete shape,regular contour,and clear edge.Compared with other advanced segmentation techniques,our methods are more robust when considering images with different appearances and achieve more satisfactory segmentation effects.  相似文献   

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