Origin and evolution of alkali basaltic magma in the Okinawa Trough

I~IOXThe Okinawa Trough is an extending back--arc basin between the East China Sea Shelf andthe Ry'Ukyu Island Arc of Japan. There are widespreadly distributing acid pumice in the troughand a little basalt just in some area of the extending center. There have been some detailed rePOrtsabout the mineralogy and petrochemical feature of the subalkali tholeiite and alkali trachyte in thetrough (Zhai and Gan, 1995; Li et al., 1997; Qin and Zhai, 1988). This paper mainly reportselectron mic…     

基于子波分析的悬浮物散射信号特征提取实验研究

概述了应用子波分析对悬浮物测量中的声散射信号进行特征提取的方法 ,并对声散射信号识别的研究进行了探讨。对实测数据的实验取得了较好的结果     

海上油井密封套管内海水冻胀特性试验分析

1998年首次进行了海上油井密封套管内海水冻胀特性模拟试验,建立了一套各种参数的测量系统.文中介绍了管内海水冻结过程、海水过冷温度、结冰水温、轴向冻胀力以及管体应变测量结果.     

A fuzzy distinguishability on species composition similarities of pelagic fishes in different years in the southern Taiwan Strait

I\rnooUcrIoxThe drpdric fish species cor-npositlon is an imPOrtant element 1n the study of fish ecologyand plays an important guiding role ln fishery preduction and roouLrces rnanagement. Lin(l988) and Zhang (1994 and l995) have studied the simi1drities of mpulation COtwsition ofame s1ngle species of different yea-rs including hairtail Trichuras haumee and yellDw cndertwinena cmi. But no rePOrt is available on the discridrination of the sidrildrities amongmuLlt1ple sPecies composition of…     

动力定位系统与单波束测深仪在科考船定点作业中的应用

科考船定点作业时会受到海洋风、涌、浪、流等外界环境因素影响，导致工作效率降低，原位测量精度下降，甚至影响作业安全。动力定位系统 （DP） 具有自动定位功能，能够抵抗外界环境因素的影响，可实现科考船高精度定点控位。 单波束测深仪不仅可以测量水深，也可反映水下设备深度信息，可以起到辅助监控水下设备功能。本文在介绍定点作业施工现状与局限性的基础上，分析 DP 系统与单波束测深仪工作原理，以“向阳红 01”船为载体，在定点作业时开启 DP 系统与单波束测深仪，发现该方法可以提高科考船定点作业工作效率、原位测量精度并保障作业安全，可为其他科考船定点作业提供参考。     

Underice Operation of SJT-5 ROV

- The authors have used a low-cost ROV of observation type for underice surveying of the Nen-Jiang Cross-river oil pipe line in the Da Qing oil field. The operation method, process and the safety measures for severe cold areas are presented. The fruitful tries and experience may be useful to ROV operators in severe cold areas.     

应用北太平洋表层水温及环流场进行海冰预报

渤海及黄海北部处在中纬度地带,每年冬季都有不同程度的结冰现象。以辽东湾结冰时间最长,全部结冰日数平均为100多天,约占全年的三分之一。从全海区看,建国后冰情较重的有1957、1968、1969、1977年的1、2月份,尤其是1969年,渤海海面发生了该海区历史上罕见的冰封,整个海面几乎全部被海冰所覆盖,严重阻碍了海上的航运交通及海上石油开采工作,从而给国民经济带来很大损失。     

Analytically derived wind-wave directional spectrum part 1. Derivation of the spectrum

In contrast with the usual method to obtain the wind-wave directional spectrum by multiplying the frequency spectrum with an empirical directional function, the authors attempt to derive analytically the directional spectrum by adopting proper spectral form and using effective parameters, namely, the zero order momentm ₀ of the wind-wave frequency spectrumS(), its peak frequency ₀ and the so-called peakness factorP=₀ S(₀)/m ₀, where is angular frequency. The directional spectrum is given in a form of frequency spectrum for each direction. The spectral directionality depends on, in addition to frequency, the wind-wave growth status, for the peakness factorP as introduced by the authors previously is a measure of the wave development stage. The salient features of the directional spectrum, comparison with existing formulas and the verification of the spectrum by observational data are to be given in the Part 2 of the paper.Project supported by the National Natural Science Foundation of China.     

Seasonal variations in the speciation of dissolved iodine in the Chesapeake Bay

The speciation of dissolved iodine and the distributions of the iodine species in the deep Chesapeake Bay underwent seasonal variations in response to changes in the prevailing redox condition. In the deep water, the ratios of iodate to iodide and iodate to inorganic iodine decreased progressively from the Winter through the Summer as the deep water became more poorly oxygenated before they rebounded in the Fall when the deep water became re-oxygenated again. The composition of the surface water followed the same trend. However, in this case, the higher biological activities in the Spring and the Summer could also have enhanced the biologically mediated reduction of iodate to iodide by phytoplankton and contributed to the lower ratios found during those seasons. Superimposed on this redox cycle was a cycle of input and removal of dissolved iodine probably as a result of the interactions between the water column and the underlying sediments. Iodine was added to the Bay during the Summer when the deep water was more reducing and removed from the Bay in the Fall when the deep water became re-oxygenated. A third cycle was the inter-conversion between inorganic iodine and ‘dissolved organic iodine’, or ‘‘DOI’’. The conversion of inorganic iodine to ‘DOI’ was more prevalent in the Spring. As a result of these biogeochemical reactions in the Bay, during exchanges between the Bay and the North Atlantic, iodate-rich and ‘DOI’-poor water was imported into the Bay while iodide- and ‘DOI’-rich water was exported to the Atlantic. The export of iodide from these geochemically reactive systems along the land margins contributes to the enrichment of iodide in the surface open oceans.     

完全混合活性污泥法处理含海水污水时基质降解与需氧量之间的关系

文章采用完全混合活性污泥法研究了大生活用海水进入城市污水系统后 ,不同海水盐度下基质降解与需氧量之间的关系。结果表明随着污水中海水比例的增加 ,代谢单位重量有机物所需的氧量和污泥自身氧化需氧率也呈增加趋势