火山玻璃风化层的透射电镜研究   总被引：2，自引：0，他引：2  

张秉良  洪汉净  刘辉  盘晓东 《矿物学报》2008,28(3)

利用透射电镜(TEM)和X射线能谱(EDX)研究了长白山天池火山1000年和4000年前两次大喷发产生的火山玻璃风化层特征.TEM分析显示,4000年前大喷发浮岩中的火山玻璃风化层平均厚度3.7 mm,1000年前大喷发浮岩中的火山玻璃风化层平均厚度为1.0 mm.EDX分析显示,两次大喷发浮岩中的火山玻璃风化层化学组成与火山玻璃相比富Al、Fe,而si减少.火山玻璃风化层富Al发生在Al的浓度较高的中到弱酸溶液中(pH=5～6),火山玻璃表面形成含有少量的非晶质的Al、Si、Fe物质,这些非品质的次生物质是火山玻璃风化早期阶段形成的.天池火山喷发物中火山玻璃的微观特征的差异可能与火山喷发年代和喷发后的环境有关,研究天池火山不同期次喷发物中火山玻璃的微观特征具有一定的理论和实际应用价值.  相似文献   

南太平洋辐合带(SPCZ)的特征分析   总被引：1，自引：0，他引：1  

吴增茂  陈登俊  温之平 《中国海洋大学学报(自然科学版)》1993,(Z2)

根据热带西太平洋卫星云图资料及流场特征分析,讨论了南太平洋辐合带(SPCZ)的演变特征和形成机理。提出SPCZ是反映西太暖池同东太冷舌海气耦合系统以及暖池大气同相邻陆区大气间相互作用的重要特征。主要表现为在12～2月的热带西太平洋上的NW/SE辐合带,其形成原因主要应归因于西太暖池本身,以及暖池与东太赤道冷水舌强度与相对位置改变引发的Walker环流位置与走向的变动,另外,新几内亚岛及澳洲大陆也有重要影响。  相似文献   

Spectral Analysis of Nonlinear Drag Forces     

马汝建  李桂喜赵东 《中国海洋工程》2005,19(2):325-332

The spectral properties of nonlinear drag forces of random waves on vertical circular cylinders are analyzed in this paper by means of nonlinear spectral analysis. The analysis provides basic parameters for estimation of the characteristic drag forces. Numerical computation is also performed for the investigation of the effects of nonlinearity of the drag forces.The results indicate that the wave drag forces calculated by linear wave theory are larger than those calculated by the third order Stokes wave theory for given waves. The difference between them increases with wave height. The wave drag forces calculated by use of hnear approximation are about 5% smaller than their actual values when measured in the peak values of spectral densities. This will result in a safety problem for the design of offshore structures. Therefore, the nonlinear effect of wave drag forces should be taken into comidemtion in design and application of important offshore structures.  相似文献   

周期浅析     

战淑芸  杨淑瑞 《海洋预报》1992,9(4):47-51

本文分析了滑动平均的数据处理方法对周期分析结果产生的影响。提出了过程变量同号积分的数据处理方法,并对亚洲西风指数序列进行了试验分析。分析结果表明,周期的长短与振幅的大小有密切关系,亚洲逐日西风指数的周期振荡具有明显的季节特征。  相似文献   

Cod migration patterns in relation to temperature: analysis of storage tag data   总被引：1，自引：0，他引：1  

Stensholt  Boonchai K. 《ICES Journal of Marine Science》2001,58(4):770-793

  相似文献   

海水分光反射率与叶绿素浓度的相关分析     

傅克忖  曾宪模 《海洋科学进展》1995,(1)

通过对东京湾两年度不同季节海水分光反射率与叶绿素浓度进行统计分析，结果表明，叶绿素浓度Ｃ与两谱段分光反射率之比Ｒｗ（λｊ）／Ｒｗ（λｊ）具有幂函关系Ｃ＝Ａ［Ｒｗ（λｊ）／Ｒｗ（λｊ）Ｂ。两者的对数显示出较好的线性关系，即ｌｏｇＣ＝ｌｏｇＡ＋Ｂｌｏｇ［Ｒｗ（λｊ）／Ｒｗ（λｊ）］。负相关系数达０．９９。相关方程之一为Ｃ＝３．３２９［Ｒｗ（５２０）／Ｒｗ（５５０）］－１．３８４（１９８７年６月初）．在梅雨季节之后，相关方程为Ｃ＝１２．６８［Ｒｗ（５２０）／Ｒｗ（５５０）］－２．０１０（１９８８年８月）。这表明了海湾或混浊的沿岸水质，在叶绿素浓度算法中，统计参数Ａ和Ｂ的确立，要基于不同季节不同水质的现场观测资料。  相似文献   

Research on the spectral analysis and test method of period signals in monthly mean sea level     

Ma Jirui  Tian Suzhen  Zheng Wenzhen  Chai Xinmin 《海洋学报(英文版)》1995,14(2):181-190

Ｒｅｓｅａｒｃｈｏｎｔｈｅｓｐｅｃｔｒａｌａｎａｌｙｓｉｓａｎｄｔｅｓｔｍｅｔｈｏｄｏｆｐｅｒｉｏｄｓｉｇｎａｌｓｉｎｍｏｎｔｈｌｙｍｅａｎｓｅａｌｅｖｅｌ￥ＭａＪｉｒｕｉ；ＴｉａｎＳｕｚｈｅｎ；ＺｈｅｎｇＷｅｎｚｈｅｎａｎｄＣｈａｉＸｉｎｍｉｎ（Ｒ...  相似文献   

基于子波分析的悬浮物散射信号特征提取实验研究     

张锁平 《海洋技术学报》2002,21(2):60-63

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  相似文献   

Probabilistic Models for the Probability of Wave Breaking and Whitecap Coverage Based on Kinematic Breaking Criterion     

郑桂珍  徐德伦 《中国海洋工程》2004,18(3):357-370

More and more researches show that neither the critical downward acceleration nor the critical slope of water waves is a universal constant. On the contrary, they vary with particular wave conditions. This fact moders the models either for the probability of wave breaking B or for the whitecap coverage W based on these criteria difficult to apply. In this paper and the one which follows we seek to develop models for the prediction of both B and W based on the kinematical criterion. First, several joint probabihstic distribution functions (PDFs) of wave characteristics are derived, based on which the breaking properties B and W are estimated. The estimation is made on the assumption that a wave breaks ff the horizontal velocity of water particles at its crest exceeds the local wave celerity, and whitecapping occurs in regions of fluid where water particles travel faster than the waves. The consequent B and W depend on wave spectral moments of orders 0 to 4.Then the JONSWAP spectrum is used to represent the fetch-limited sea waves in deep water, so as to relate the probahility of wave breaking and the whitecap coverage with wind parameters. To this end, the time-averaging technique proposed by Glazman (1986) is applied to the estimation of the spectral moments involved, and furthermore, the theoretical models are compared with available observations collected from published literature. From the comparison, the averaging time scale is determined. The final models show that the probability of wave breaking as well as the whitecap coverage depends on the dimensionless fetch. The agreement between these models and the database is reasonable.  相似文献   

东海温度锋的分布特征及其季节变异   总被引：8，自引：4，他引：8  

汤毓祥 《海洋与湖沼》1996,27(4):436-444

根据１９３４－１９８８年东海水文观测资料，重点分析东海温度锋的分布特征及其季节变异，并结合近期中日黑潮合作调查研究成果，初步探讨温度锋季节变异和水团演变的关系，所得主要结论是：（１）东海不仅常年存在浙闽沿岸锋，东海北部陆架锋和黑潮锋，而且、春、夏两季，在东海南部还出现一条东海中部出架锋。（２）江海温度锋季节变化的特点是：冬季，锋的宽度和强度皆是表层最强，夏季，表层温度锋仅出现在浙江近岸小范围海域。  相似文献