On the long-term joint distribution of characteristic wave height and period and its application

By analysing the scatter diagrams of characteristic the wave height H and the period T on the basis of instrumental data from various ocean wave stations, we found that the conditional expectation and standard deviation of wave period for a given wave height can be better predicted by using the equations of normal linear regression rather than by those based on the log- normal law. The latter was implied in Ochi' s bivariate log-normal model(Ochi. 1978) for the long-term joint distribution of H and T. With the expectation and standard deviation predicted by the normal linear regression equations and applying proper types of distribution, we have obtained the conditional distribution of T for given H. Then combining this conditional P(T / H) with long-term marginal distribution of the wave height P(H) we establish a new parameterized model for the long-term joint distribution P(H,T). As an example of the application of the new model we give a method for estimating wave period associated with an extreme w     

A study on the exchange additivity of zinc in solid mixtures in seawater——Ⅱ.Stepwise exchange in δ-MnO2/montmorrillonite mixture

In this study the zinc exchange process and the reason for the non-additive exchange of δ-MnO2/montmorrillonite have been investigated. The results suggest that with pH increasing from 2 to 8, the stepwise exchange of zinc occurs on δ-MnO. and montmorrillonite in their mixture.At low pH zinc ions are bound on δ-MnO2, while at high pH, the exchange on montmorrillonite dominates the surface interaction in the mixture. The study demonstrates that the stepwise exchange and the heterogeneity of the binding sites on δ-MnO2 surface are the reason for the non-additive exchange. It is also shown that when δ-MnO2 amounts to 5 %, zinc exchange on sea sediments is controlled by 8-MnO2.     

Competition within the marine microalgae over the polar dark period in the Greenland Sea of high Arctic

Abstract-With the onset of winter, polar marine microalgae would have faced total darkness for aperiod of up to 6 months. A natural autumn community of Arctic sea ice microalgae was collected fordark survival experiments from the Greenland Sea during the ARKTIS-XI/2 Expedition of RV Po-larstern in October 1995. After a dark period of 161 days, species dominance in the algal assemblagehave changed from initially pennate diatoms to small phytoflagellates (<20μm). Over the entire darkperiod, the mean algal growth rate was-0.01 d~(-1). Nearly all diatom species had negative growthrates, while phytoflagellate abundance increased. Resting spore formation during the dark period was ob-served in less than 4.5% of all cells and only for dinoflagellates and the diatom Chaetoceros spp. We as-sume that facultative heterotrophy and energy storage are the main processes enabling survival during thedark Arctic winter. After an increase in light intensity, microalgal cells reacted with fast growth withindays. Phytoffa     

基于EOF分析对南海西北海域水体光谱特性的研究

This study presents an analysis of the spectral characteristics of remote sensing reflectance(R_(rs)) in northwestern South China Sea based on the in situ optical and water quality data for August 2018.R_(rs)was initially divided into four classes,classes A to D,using the max-classification algorithm,and the spectral properties of whole R_(rs) were characterized using the empirical orthogonal function(EOF) analysis.Subsequently,the dominant factors in each EOF mode were determined.The results indicated that more than 95% of the variances of R_(rs) are partly driven by the back-scattering characteristics of the suspended matter.The initial two EOF modes were well correlated with the total suspended matter and back-scattering coefficient.Furthermore,the first EOF modes of the four classes of R_(rs)(A-D R_(rs)-EOF_1) significantly contributed to the total variances of each R_(rs) class.In addition,the correlation coefficients between the amplitude factors of class A-D R_(rs)-EOF_1 and the variances of the relevant water quality and optical parameters were better than those of the unclassified ones.The spectral shape of class AR_(rs)-EOF_1 was governed by the absorption characteristic of chlorophyll a and colored dissolved organic matter(CDOM).The spectral shape of class B R_(rs)-EOF_1 was governed by the absorption characteristic of CDOM since it exhibited a high correlation with the absorption coefficient of CDOM(a_g(λ)),whereas the spectral shape of class C R_(rs)-EOF_1 was governed by the back-scattering characteristics but not affected by the suspended matter.The spectral shape of class D R_(rs)-EOF_1 exhibited a relatively good correlation with all the water quality parameters,which played a significant role in deciding its spectral shape.     

潮汐分析和预报的准调和分潮方法 Ⅱ.短期观测的分析

目前,调和方法仍然是潮汐的分析和预报中的一种主要的基本方法,其关键在于求得尽可能准确的调和常数。在湖汐分析中,经常遇到的是对于中、长期(半个月以上)记录的处理,对于这样的资料,已有许多良好的分析方法可以采用。但是,有时我们也会遇到需要处理的短期观测资料,特别对于潮流,由于对它进行观测比水位观测要困难,常常不能获得较长期的记录,而需要从短期记录中分析出调和常数来。处理短期记录的方法也有不少,其中较为常用的是英国海军部的几种方法。这些方法只能处理一次或二次周日观测记录,当观测天数较多时,只能分组进行计算得到几组调和常数,然后再求平均值由于各组的天文条件的差別,调和常数的准确度常常有相当大的差异,而计算平均值时却没有加权,这就影响了结果的可靠性。本文建议的方法将可以直接分析任意多次周日观测记录,因而简化了计算并能得到更准确的结果。     

罗氏沼虾育苗用水中Mg2+与Ca2+含量及Mg2+/Ca2+对出苗率的影响

１９９１年３－６月和１９９２年３－６月在南汇县东海水产养殖公司对罗氏沼虾育苗用水调配原则与不同基础水的调配方法进行试验研究。结果表明，育苗用水中Ｍｇ＾２＋与Ｃａ＾２＋含量及Ｍｇ＾２＋／Ｃａ＾２＋必须达到一定的范围，这是调配的基本原则。以鱼塘水作基础水时，需添加６种化学药品，其中Ｍｇ＾２＋与Ｃａ＾２＋含量可适范围分别为３００．０－４４０．０ｍｇ／Ｌ与１７０．０－２４４．０ｍｇ／Ｌ，Ｍｇ＾２＋／Ｃａ＾     

紫菜一新种——福建紫菜的研究

于1978年1月在福建莆田县乐屿岛采集紫菜属标本,进行分类研究。经鉴定表明,其中一种系新种,定名为福建紫菜Porphyra fujianensis sp.nov.。分类方法见曾呈奎等(1962)。本种特征为:藻体长带状,边缘细胞为刺缘型;雌雄同体,精子囊器与果孢子囊成条状或块状,混生或呈镶嵌式分布,形似条斑紫菜;精子囊器分裂式为(?)A_4B_4C_4,果孢子囊分裂式为♀A_2B_4c_2;藻体产生单孢子,进行无性繁殖。模式标本存放于厦门水产学院养殖系。     

海底管道开沟机械的技术经济性能评定与选型

本文在对水下管道开沟机械的需求市场、实际应用和研制开发动向作深入调研的基础上，选择水下管道开沟机械特有的技术先进性、适用性、安全可靠性以及经济性评价指标，构造评价模型，对水下管道施工作业中广为应用的水力冲射开沟机械、海底管道犁、机械开沟机和土壤液化法埋管设备及其机型的技术经济性能作了较为详尽地分析对比及综合评价。在此基础上，笔者提出了水下管道开沟机械的一般选型原则和对我国海底管道开沟机械研究开发工     

用铀系定年法测定南永1井珊瑚礁年龄

运用铀系定年法首次对南水1井珊瑚礁岩心中的两个层位进行测年,结果与~(14)C测年一致,证实在晚更新世与全新世之间存在沉积间断面。     

海藻糖类的气相色谱分析 Ⅱ.红藻及红藻多糖中D-半乳糖和3, 6-内醚半乳糖的测定

红藻中的糖类主要以多糖形式存在(琼胶、卡拉胶等)，其中主要的单糖组分是D-半乳糖和3, 6-内醚半乳糖，除此之外还含有少晕的木糖、葡萄糖及甘露糖等成分。由于各单糖的相互干扰，难以用比色等着通化学分析方法对每一种单糖准确地定性定量。作者曾研究过褐藻中单糖的气相色谱测定法, 但该法不能测定3, 6-内醚半乳糖，囚为这种内醚糖对酸水解不稳定。据Dutton和Nozawa等人报道, 将多糖经甲醇分解后进行气相色谱分析，结果令人满意。本文用琼胶(Difco bacto-agar)作代表，研究探讨了红藻胶甲醇-HCI分解的条件，确定了红藻胶中D-半乳糖和3, 6-内醚半乳糖的气相色谱分析方法，并将其应用于红藻中D-半乳糖和3, 6-内醚半乳糖的分析。