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31.
作者于1989年7月和11月分别收到黄宗国先生采自大亚湾附着物试板和香港大学张佩珊女士采自香港潮间带的一批标本,还有严文侠先生于1990年6月采自珠江口浮标的标本,共计37号,经整理鉴定为8科12属15种。其中8种为中国近海的首次纪录。
以上材料大部分取自附着物试板和浮标,小部分采自潮间带。 相似文献
32.
Li Dashan Shen Ying Ren Rushu Chen Yao
Senior Engineer River Harbour Department Nanjing Hydraulic Research Institute Nanjing Engineer River Harbour Department Nanjing Hydraulic Research Institute Nanjing Associate Professor Hohai University Nanjing Master Hohai University Nanjing 《中国海洋工程》1997,(1)
In this paper,the characteristics of density current under the action of waves are describedwith the help of flume experiment and theoretical analysis.The study shows that turbid water under the ac-tion of the waves can present three types of motion,i.e.significant stratification,fragile stratification andstrong mixing.The motion of turbid water presents significant stratification when(H/D)/△ρ/ρ~(1/2)≤4.5,generally this state is known as density current.The formulas of motionvelocity,thickness,and discharge of density current moving on horizontal bottom are derived by use of ba-sic equations such as momemtum equation,equation of energy conservation and continuity equation offluid.The time-average velocity and the thickness of density current under the action of waves have a rela-tionship with such parameters as relative density(△ρ/ρ),wave height(H),and water depth(D).Whenthese parameters are determined,the time-average thickness and motion velocity of density current are al-so determined.The relat 相似文献
33.
34.
该文对目前工业上生产纳米碳酸钙的方法作了较为详细的综述。对一步碳化法、两步碳化法、多段喷雾碳化法、旋转填充床碳化反应器碳化技术制备链形、纺锤形、球形、立方形等不同形状的纳米碳酸钙材料的方法进行了比较和总结 相似文献
35.
该文建立高效凝胶渗透色谱法 (HPGPC) ,明胶比浊法 ,氧瓶燃烧法三种分析方法考察海洋硫酸多糖药物几丁糖酯的稳定性 ,采用这三种方法分别考察几丁糖酯原料药在高温、高湿、强光照射及加速条件下分子量及分布宽度、样品中硫酸根含量及样品含量的变化情况。结果表明 :三种方法均适用于几丁糖酯的稳定性考察 ,几丁糖酯在上述影响因素条件下稳定性良好 相似文献
36.
Ching-Hui Tsai Shu-Kun Hsu Yi-Ching Yeh Chao-Shing Lee Kanyuan Xia 《Marine Geophysical Researches》2004,25(1-2):63-78
Magnetic data suggest that the distribution of the oceanic crust in the northern South China Sea (SCS) may extend to about 21 °N and 118.5 °E. To examine the crustal features of the corresponding continent–ocean transition zone, we have studied the crustal structures of the northern continental margin of the SCS. We have also performed gravity modeling by using a simple four-layer crustal model to understand the geometry of the Moho surface and the crustal thicknesses beneath this transition zone. In general, we can distinguish the crustal structures of the study area into the continental crust, the thinned continental crust, and the oceanic crust. However, some volcanic intrusions or extrusions exist. Our results indicate the existence of oceanic crust in the northernmost SCS as observed by magnetic data. Accordingly, we have moved the continent–ocean boundary (COB) in the northeastern SCS from about 19 °N and 119.5 °E to 21 °N and 118.5 °E. Morphologically, the new COB is located along the base of the continental slope. The southeastward thinning of the continental crust in the study area is prominent. The average value of crustal thinning factor of the thinned continental crust zone is about 1.3–1.5. In the study region, the Moho depths generally vary from ca. 28 km to ca. 12 km and the crustal thicknesses vary from ca. 24 km to ca. 6 km; a regional maximum exists around the Dongsha Island. Our gravity modeling has shown that the oceanic crust in the northern SCS is slightly thicker than normal oceanic crust. This situation could be ascribed to the post-spreading volcanism or underplating in this region. 相似文献
37.
报道一种新的有效催化剂-碘-钒盐和在一定条件下合成四溴邻苯二甲酸酐的方法。探讨催化剂的组成配比、用量、温度及废酸循环使用等因素对合成方法的影响。该催化剂的催化效果和常用的碘、碘-铁催化剂相同,适用于四溴邻苯二甲酸酐的合成。 相似文献
38.
A bottom longline fishery operated in the EEZ of New Caledonia from 1988 to 1991. Fishing focused on five seamounts with summits at depths ranging from 500 to 750 m. The target species was alfonsino, Beryx splendens. As the soundings available from marine charts were not detailed enough, the fishing masters had to make their own charts in order to set the gear in the right location. A series of 11 scientific cruises devoted to a research program on alfonsino was launched in late 1991. During the first scientific cruises, several days were spent mapping the seabed to improve the existing knowledge of the topography of three seamounts by coupling the EDO echosounder depth measurements to the GPS positions. As this procedure is slow, it is applicable to limited areas or, if a wider grid is used, to large zones to locate major structures such as ridges and seamounts. The emergence of the multibeam echosounder has greatly improved seabed mapping performance. This tool seems to fit the requirement of exploratory deep-bottom fishing particularly well, as it covers large areas while providing details of the bottom. The EM 12 was used to obtain bathymetry and imagery of the SE portion of the EEZ of New Caledonia, covering an approximate area of 70,000 km2 in two weeks. For depths ranging from 500 to 4,500 m, the results were impressive. They confirmed the known major features and provided greater topographical detail, revealing fine unknown structures. They also provided information on the type of substratum, information which might influence the fishing strategy. Finally, they made it possible to obtain an accurate estimate of the exploitable area which in turn led to new stock estimates. 相似文献
39.
藤壶属(Genus Balanus)是甲壳类蔓足亚纲(Subclass Cirripedia)藤壶科(Family Balanidae)中最大的一属,它在有害海洋附着生物中是主要组成成分。许多种附着于船底、水下设施或建筑物上,致使船舰燃料消耗增加,航速减低,降低浮标浮力,缩小管道通路,侵占某些水产养殖对象的有效附着面,污损养殖架筏和绳索,加快水下金属的腐蚀等,对海防、海运交通、工业和渔业常造成一定危害,同人类的关系颇为密切。随着我国科学事业的发展,特别是附着生物防除工作的进展,对于种类的确切鉴定和生物学及生态学资料需要日益增多,只有在搞清种类的基础上,根据不同种的生物学和生态特征,采取相应的措施,才能有效地进行防除工作。
中国近海的藤壶属,国内外仅有一些零星记载,缺乏全面而系统的报告。我们早在五十年代,就注意到我国沿海常见的一些主要附着生物,特别是当时作为“布纹藤壶” Balanus Amphitrite communis Darwin(=B.reticulatus Utinomi)和“克氏藤壶”Balanus Amphitrite krügeri Nilsson-Cantell(=B.uliginosus Utinomi)描记的两个类型,无论在栖息环境、繁殖习性或幼虫形态上都有显著差异,因而怀疑它们不是一个种内的亚种,而应属于不同的种。为了解决上述和类似的问题,给生态和防除研究工作提供更为准确的基本资料,我们对藤壶亚目的种类进行了系统的研究,本文是研究报告的第一部分。根据的是中国科学院海洋研究所历年采集收藏的标本,共鉴定31种和亚种,分隶于7个亚属,其中有6新种,有9种在我国是首次记录(种名录见190页)。新种的模式标本均保存于中国科学院海洋研究所。 相似文献
40.
运用电脉冲转基因仪对合浦珠母贝卵子进行电脉冲处理以优化电穿孔法转基因的电击参数。实验中调制百分比:100%;脉冲间隔:1.0s:电极距离:2mm;脉冲个数:5个,参数保持不变。用不同的电脉冲参数组合(脉冲电压100-400V、脉冲持续时间0.5~3.0ms、脉冲频率10~50kHz,共28个组合)对卵子电击,然后加入精子进行授精,统计各组受精率和孵化率,以受精率和孵化率达到50%以上为衡量指标。结果表明,合浦珠母贝卵子对低脉冲频率和高电压非常敏感,当频率低于20kHz或脉冲电压高于400V时对卵子损伤较大。脉冲持续时间对其影响不大,适应范围较宽。优化的转基因电击脉冲参教组合为:脉冲电压1.0kV/cm,脉冲持续时间20ms,脉冲频率50kHz,或者脉冲电压1.5kV/cm,脉冲持续时间1.5ms,脉冲频率50kHz。 相似文献