Distribution of Boron in Some Egyptian Aquatic Environments

Concentrations of boron in seawater (from four regions along the Alexandria coastline, subjected to land disposal), brackish water (Lake Edku) and drains water (e.g. El-Umum Drain) were determined during the period from February to August 2000. Boron was determined spectrophotometrically by a modified curcumin method. For Lake Edku, boron concentration fluctuated between 0.023 and 0.105 mmol/l. There are several factors that affect the concentration of B in the Lake water: (a) effect of the drainage water via El-Khairy and Barsiek Drains, (b) utilization of boron by hydrophytes, and (c) water exchange through the sea-lake connection. It may be concluded that the level of boron in the Lake water cannot be considered a substantial hazard to the Lake organisms. Boron concentration varied from 0.392 to 0.522 mmol/l in seawater samples and from 0.141 to 0.458 mmol/l in the sites where the water from the drains (El-Umum Drain and El-Noubaria Canal) mixed with the seawater. The broader variation of boron (mmol/l)/salinity ratios for seawater samples (0.0106–0.0138) may be due to that the samples were collected from the upper seawater layers, where contributions from land run-off, atmospheric precipitation and differences in the biota affect the concentration. This revised version was published online in July 2006 with corrections to the Cover Date.     

对虾养殖生态系中有机碳的初步研究本研究由

对于围隔养殖对虾生态系中有机碳的变动进行了研究 ,结果表明 :溶解有机碳 (DOC)含量波动在 5 .2 99～ 13.39mg/ L之间 ,平均为 8.5 3mg/ L± 2 .2 5 mg/ L;颗粒有机碳 (POC)含量波动在0 .6 5～ 6 .6 3mg/ L之间 ,平均为 3.2 5 mg/ L± 1.76 mg/ L;总有机碳 (TOC)含量波动在 6 .92～ 2 0 .0 2mg/ L之间 ,平均为 11.78mg/ L± 3.82 mg/ L ;其中 DOC∶ POC∶ TOC为 0 .72∶ 0 .2 8∶ 1。各种有机碳组分的含量明显高于自然海水中各种有机碳的含量 ;各种有机碳组分的含量在养殖期间总体上呈上升的趋势 ;其变化与 DCOD的变化呈显著线性正相关的关系。     

秋季东海黑潮锋面涡旋的特点

本文根据１９８８年１０月２０～２４日“向阳红０９号”调查船在奄美大岛以西海区进行调查时，在陆架斜坡上的表均温层的底部，即５０ｍ附近的深层上，出现一个黑潮锋面涡。不论在平面上形成的特点，还是在断面上水系配置的形式，它与春季黑潮锋面涡的特征极为相似。说明秋季东海同样存在陆架水与黑潮水在水平方向交换与混合。     

九龙江河口区水体中的226Ra和228Ra

用ＭｎＯ２－纤维富集大体积水样中的Ｒａ同位素，并用直接射气法测定２２６Ｒａ和２２８Ａｃ的β计数法测定２２８Ｒａ的方法，研究了九龙江河口区２２６Ｒａ，２２８Ｒａ的行为，结果表明：在该河口区２２６Ｒａ，２２８Ｒａ均呈非保守行为，２２６Ｒａ，２２８Ｒａ的最高值分别在盐度为１９和９处测得。２２８Ｒａ／２２６Ｒａ）Ａ．Ｒ．值在盐度小于１９的区域约为３左右。与世界其他河口区相比，九龙江河口区的２２６Ｒａ，２２     

台湾海峡中北部上升流区各种形态磷的化学特性

根据１９８８年７月调查资料讨论了台湾海峡中北部海域夏季上升流区各种形态磷的分布特征。结果表明，上升流中心区（即海坛岛东侧一带水域）具有低温、高盐、低溶解氧；ＤＩｐ，ＴＤＰ，ＰＰ，ＴＰ较高；ＤＯＰ较低（０．２７）；及ＤＩＰ／ＤＯＰ比值（约为１）较高的特性。ＤＯＰ是该海域磷的主要形态（占ＴＰ的４９．２％），其含量分布及其形态转化与生物活动直接相关，是该海域生物生产力高的体现。     

The Nonlinear Wave Force on a Circular Cylinder in Shallow Water

Based on the 1st order cnoidal wave theory, the nonlinear wave diffraction around a circular cylinder in shallow water is studied in this paper. The equation of the wave surface around the cylinder is formulated and by using this formula the wave surface elevation on the cylinder surface can be obtained. In this paper, the formula for calculating the cnoidal wave force on a circular cylinder is also derived. For the wave conditions which are often encountered in practical engineering designs, the ratios of the nonlinear wave forces to the linear wave forces are calculated, and the results are plotted in this paper for design purposes. In order to verify the theoretical results, model tests are conducted. After comparing the test results with the theoretical ones, it is concluded that, in shallow water, for the case of T g / d~(1/2) > 8-10 and H / d > 0.3, the cnoidal wave theory should be used to calculate the wave action on a cylindrical pier.     

点带石斑鱼人工育苗技术

通过58批次的人工育苗试验，总结点带石斑鱼人工育苗技术；阐述了育苗池、育苗的环境条件、鱼苗不同生长阶段的饵料及投喂方法、育苗水质管理及生产中的操作方法等；讨论了如何解决开口饵料问题和出现3个危险期的原因等。     

台湾及其邻海的重力特征与构造、地震的关系

分析认为，在台湾及其邻海的重力场中，具有短波长特征的空间重力异常受地形与海深所制约．玉山的200×10     

东海黑潮水与陆架水的季节性输运和交换

在流星分析和ｔ－Ｓ点聚分析的基础上，在台湾东北部ＩＳ断面和东海中部ＰＮ断面上选取适当的纵剖面作为分界面，将以面分成东、西两侧，计算了界面两侧的海水交换星。结果表明：１．东海陆架区海水交换可归纳为两种类型，即“穿插型”和“进退型”。２．参与分界面处海水交换总量的年平均是夏季最大，春、秋季次之，冬季最小。黑潮水向陆架区输运量为０．５８×１０６ｍ３／ｓ，陆架水向黑潮刚输运量为０．８４×１０６ｍ３／ｓ；参与交换的总量为１．４２×１０６ｍ３／ｓ．３．相对输运量计算结果表明；黑潮水对陆架区水文状况的影响是冬季最强，秋、春季次之，夏季最弱，而陆架水对黑潮区水文状况的影响是夏季最大，秋季次之，春季和冬季最小。