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1.
Five species of marine phytoplankton, Phaeodactylum tricornutum, Chaetoccros minutissimus, Platymunas suhcordiforinis, Nitzschia sp. and Dunaliella sp. were analyzed for the contents of total nitrogen, free amino acid and total amino acid. Their total nitrogen content was relatively high, ranging 3.37-7.6% and the total amino acid content 15.1-36.0%, Glu, Asp, Leu, Ala, Arg, and Gly being the main components. The free amino acid content in two species, Dunalietta sp. and Nitzschia sp. ranged 0.13-0.30%, in which Arg, Ala, Glu, and Asp were predominant. The crude protein in phytoplankton is high enough to be comparable with that of higher classes of seaweed such as Porphyra and Laminaria. 相似文献
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王渊源 《海洋学报(英文版)》1985,4(3):471-476
This article presents an instrumental analysis of the kinds and contents of basic amino acids contained in 9 planktonic algae specimens and a comparison between the nutritive value of amino acids in the 9 planktonic aglae and that of amino acids in prawn. Moreover, a comparison is made between contents of various planktonic algae amino acids essential to animails. It is concluded that such algae as N. Closterium., f. finutissima, C. Simplex var.CaIcitrans, P. tricornutum, Pla. Subc-ordiformis and S. costatum are nutritive foodstuffs. 相似文献
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The paper preliminarily discusses the effects of cadmium pollution on the alkaline phosphatase of mussel, mytilue viridid. The results show the cadmium pollution has a inhibition on the alkaline phosphatase, and the degree of inhibition rises with the increases of concerntration if cadmium in seawater. When the concentration is within the range of 1-500 ppb, the percentage of inhibited emzyme has a linear relationship with the logarithm of cadmium concentration. The results also prove that the salinity may increase the effects of cadmium on emzyme. The inhibition which may be indirect or secondary effects is reversible.Mussels play a purification role in the waste water containing cadmium, the purification rate of which may as high as 125 mg Cd2 gram (mussel)/day. This is a prospective method in purification and removing of cadmium.The study of effects of cadmium pollution on the alkaline phosphatase of mussel shows that in the study of effects of pollutants on aquatic organisms, biochemical index may 相似文献
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This experiment was conducted to study the characteristics of absorption of amino acids by different regions of the alimentary tract and the utilization of free amino acids in the test diets of the prawn, Penaeus oricntolis.The midgut gland is the principal site of nutrient absorption. In the foregut, the digestibility coefficient of 15 amino acids tested accounted for 52.5% of the total digestibility coefficient in the entire alimentary tract. In the midgut, the digestibility coefficient was 47.5 % of the total. There was no evidence of the hindgut assimilating amino acids.The free amino acid in the test diet, methionine, was almost absorbed before entering the midgut. Methionine could not be absorbed synchronously with other amino acids bound in the dietary protein, but it did affect the synchronization of other essential amino acids. [3H]-lysine, incorporated into the test diet, was almost totally assimilated within the midgut gland. Five and a half hours after feeding, the labelled amino acid had be 相似文献
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《中国海洋工程》1988,(4)
The stress concentration behaviour of internally ring stiffened tubular T and Y joints in offshore platforms is analysed by semi-analytical variational method in this paper. The relation between SCF and geometric parameters of the joint as well as the effect of dimension and location of the ring stiffeners are discussed. A program based on this method is compiled. 相似文献
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An active substance, shedding hormone capable of inducing parent clams to spawn and sper-miate, has preliminarily been isolated from the ovaries of Ruditapes philippinarum by means of ammonia sulfate precipitate of 25% concentration and Sephadex G-25 column chromatography in present study. The biological activity of the shedding hormone is above 95%. It is composed of sorts of amino acids by determination with an amino acid automatic analyzer. The experimental results indicate that the active substance is a polypeptide. 相似文献
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This paper explores the accumulations ana distributions of Cd, Pb and Cu in clam Area granosa through determining their contents in Dlood and soft parts. The results show an order of concentration factors for these metals therein as: Cd>Cu>Pb; the values of concentration factors and the patterns of distribution are similar for Cu and Pb but different from Cd. Concentration factors in blood can reflect the enrichement abilities of soft parts. Exposure experiments have indicated that the Pb level in blood is controlled by Pb concentrations in surrouding seawater, changing with time, that the Pb cocentration causing poisoning in the seawater is 1-100 μg/l, and that the Pb content in blood and soft parts of Area granosa increases with that of Pb increasing in seawater. There exist relationships of double logatithmic concentrations for Pb among the three mediums. 相似文献
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Fixed offshore wind turbines usually have large underwater supporting structures. The fluid influences the dynamic characteristics of the structure system. The dynamic model of a 5-MW tripod offshore wind turbine considering the pile–soil system and fluid structure interaction (FSI) is established, and the structural modes in air and in water are obtained by use of ANSYS. By comparing low-order natural frequencies and mode shapes, the influence of sea water on the free vibration characteristics of offshore wind turbine is analyzed. On basis of the above work, seismic responses under excitation by El-Centro waves are calculated by the time-history analysis method. The results reveal that the dynamic responses such as the lateral displacement of the foundation and the section bending moment of the tubular piles increase substantially under the influence of the added-mass and hydrodynamic pressure of sea water. The method and conclusions presented in this paper can provide a theoretical reference for structure design and analysis of offshore wind turbines fixed in deep seawater. 相似文献
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Fixed offshore wind turbines usually have large underwater supporting structures.The fluid influences the dynamic characteristics of the structure system.The dynamic model of a 5-MW tripod offshore wind turbine considering the pile–soil system and fluid structure interaction(FSI) is established,and the structural modes in air and in water are obtained by use of ANSYS.By comparing low-order natural frequencies and mode shapes,the influence of sea water on the free vibration characteristics of offshore wind turbine is analyzed.On basis of the above work,seismic responses under excitation by El-Centro waves are calculated by the time-history analysis method.The results reveal that the dynamic responses such as the lateral displacement of the foundation and the section bending moment of the tubular piles increase substantially under the influence of the added-mass and hydrodynamic pressure of sea water.The method and conclusions presented in this paper can provide a theoretical reference for structure design and analysis of offshore wind turbines fixed in deep seawater. 相似文献
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An analytical method is proposed for the direct determination of Cd in seawater by differential pulse anodic stripping voltammetry and the derivative technique with a hanging mercury drop electrode. The process of determination is quick, simple and convenient. The concentration of Cd in seawater is only determined by adjusting the acidity of seawater to pH 2 and by taking three minutes' plating time. Sensitivity of the method is about 1×10-10M, and accuracy of that satisfactory. Relative standard deviation is about 12% when the concentration of Cd in seawater is approximately 0.04 ppb. A good agreement was obtained by a standard curve and a standard addition technique respectively from determining Cd in the same seawater. Actual measurement time per sample is about 10 min. 相似文献
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小角刺藻生长过程中溶解游离氨基酸含量在海水中的变化 总被引：2，自引：1，他引：2
于1986年12月-1987年2月在温度为25±1℃下培养小角刺藻，以HPLC法测定该藻在培养过程中海水的溶解游离氨基酸（DFAA）含量变化。结果表明，小角刺藻不仅是海水中DFAA的主要生产者，而且也是DFAA的消耗者。小角刺藻不仅在缺乏硝酸盐的时候要吸收DFAA，即使在硝酸盐充足的情况下也会吸收。在小角刺藻的生长初期，水体中DFAA的含量迅速降低，而在后期却又大大增高。在小角刺藻的不同生长阶段，水体中DFAA的组成也不同。这些都可以说明海洋中DFAA的含量、组成和地区分布是密切地同浮游植物群落的繁殖消亡过程相关联的。 相似文献
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作者对人工养殖中国对虾在不同生长时期、不同性别以及养殖对虾和天然对虾的粗蛋白和氨基酸含量进行了比较分析。得出的结论是:1、粗蛋白含量从8月开始增加,至9月达最高值。赖氨酸、亮氨酸、精氨酸、谷氨酸、甘氨酸和天冬氨酸的含量在8月以后逐月增加,增加幅度较大;其它氨基酸含量随着对虾生长有上升趋势,但不明显;2、无论是养殖对虾,还是天然对虾,雌雄虾之间其氨基酸含量几乎完全相同;3、无论雌雄,养殖对虾和天然对虾的氨基酸含量基本上一致。图6与图7所示甘氨酸和亮氨酸的差异,可能是分析上的随机误差,并非对虾本身差异所带来的不同。 相似文献
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海洋桡足类氨基酸组成及与饵料和光照的关系 总被引：4，自引：0，他引：4
桡足类氨基酸含量受其饵料浮游植物的影响。同一种桡足类因采集地不同，氨基酸的总量也不相同；19种氨基酸重量百分比随不同桡足类而异，但是不同桡足类各种氨基酸占总氨基酸的比例除胱氨酸和牛磺酸的变化比较大以外，其它都基本相同；胱氨酸和牛磺酸的变化与总氨基酸不成正比。各海区不同植食性桡足类的氨基酸组成和海区浮游植物氨基酸的组成有着很好的相关性，相关系数R^2在0．85以上。桡足类胱氨酸占总氨基酸的比例与采样站海水1％光衰减深度有很好的相关关系，其回归方程为y=0．28091nx 0．131，R^2=0．6427，n=13；随海水1％光衰减深度的增加，胱氨酸的含量以对数形式递增。桡足类氨基酸与UV的关系有待进一步研究。 相似文献
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东海陆架典型断面颗粒态氨基酸的分布及控制因素分析 总被引：3，自引：1，他引：2
采用高效液相色谱法,通过现场调查对东海典型PN断面(文中为C断面)的颗粒态氨基酸(Particulate Amino Acids,PAA)进行了分析,并结合叶绿素a(Chla)、颗粒有机碳(POC)、颗粒有机氮(PON)及颗粒态氨基酸的构型特征(D和L型)等参数探讨了该区颗粒有机氮的来源和降解情况。结果表明,在长江口最大浑浊带,受咸淡水混合和生物现场生产双重作用影响,POC、PON以及PAA的总浓度均达到了极大值,其中,受再悬浮作用影响,底层水体中的有机物呈现高度降解的状态;近岸水华区域的颗粒态氨基酸则更多来源于现场生产,而且POC/Chla质量比值与降解因子DI值的负相关特征表明冲淡水向海洋输送的过程中,现场生产力对颗粒有机碳的贡献比重逐渐增大,悬浮颗粒物也变得越来越新鲜。值得关注的是,一些D型氨基酸[如D型天冬氨酸(D-Asp),D型丙氨酸(D-Ala)]与细菌生物量之间存在良好的正相关性,暗示颗粒态氨基酸在受到物理水团和生物现场生产作用控制的同时,还受控于微微型浮游生物以及异养细菌。 相似文献
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１９９３年分析了不同大小斑节对虾肌肉中游离氨基酸含量和肌肉蛋白质 的氨基酸组成。虾体肌肉中有各种游离氨基酸存在，但数量很少，而且比例与肌肉 中结合氨基酸不一致。不同大小斑节对虾，其肌肉中氨基酸组成基本一样，不同的 是小虾的半胱氨酸、蛋氨酸含量比中虾、成虾的低；成虾的缬氨酸、异亮氨酸含量比 小虾、中虾的低，而酪氨酸、苯丙氨酸、天门冬氨酸较高。随着虾体的长大，甘氨酸、 丙氨酸的含量逐渐下降，而脯氨酸的含量升高。雌雄虾的氨基酸组成基本一致，只 是雄虾的甘氨酸含量偏低，精氨酸含量偏高。 相似文献
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本文对广西钦州(Gq)、福建霞浦(Fx)、浙江温州(Zw)、浙江三门(Zs)、浙江宁海(Zn)、浙江慈溪(Zc)等6个野生群体拟穴青蟹(Scylla paramamosain)肌肉进行了氨基酸及脂肪酸分析。共测定出19种游离氨基酸和26种脂肪酸。氨基酸含量在80.94—191.39mg/g之间, Gq为最高;总脂肪酸含量在7.97—11.38mg/g之间,Zn为最高。主要氨基酸为甘氨酸和精氨酸;主要脂肪酸为C20:5n3(EPA),占总脂肪酸含量的平均值为(22.47±5.84)%。各群体风味氨基酸和多不饱和脂肪酸含量丰富,占总氨基酸比例(TDAA/TFAA)和总脂肪酸比例(PUFA/TFA)分别为(53.62±5.43)%和(59.27±5.29)%。Zs群体的必需氨基酸含量及C22:6n3(DHA)均为最高。主成分分析结果表明:各群体的氨基酸与脂肪酸组成与含量相似性与地理距离分布具有一定的相关性,特别是Gq群体,在氨基酸与脂肪酸的分类中与其他群体区分比较明显。各群体风味氨基酸和多不饱和脂肪酸的聚类分析结果均表明:Zw、Zc与Gq群体较为接近,具有较强的甜味; Fx、Zn与Zs群体较为接近,具有较强的香味及不饱和脂肪酸营养价值。 相似文献