南沙海面的夏季风和海—气通量分析     

林锡贵  张庆荣  蔡亲炳 《热带海洋学报》1991,(1)

本文分析1984—1988年夏季南沙考察资料。结果表明:南沙海面夏季风来自南路和西路及本区的季风气流。季风潮的出现主要是南路气流加强或季风与热带气旋环流的相互作用。夏季风期间的天气形势、气象特征和海—气通量随季节和天气过程变化显著。  相似文献   

临海工程建设对厦门北面海域底质粒级组成的影响     

蔡锋  陈承惠 《台湾海峡》1992,11(1):2-7

本文根据1980年厦门港湾底质调查的70个样品,应用R型因子分析方法,对沉积物粒级组成的成因进行分析。结果表明,该海域陆续修建的临海工程对其沉积物组成影响明显,使其由粗粒组成向细粒组成变化。尤其是高集海堤的兴建,泥沙大量淤积;海堤建成后,沉积环境日益稳定,接受沉积物以粉砂、粘土占主导地位。  相似文献   

海底声学原位测试声速提取技术研究     

李红星  陶春辉  刘财  邓显明  周建平  张金辉  顾春华  何拥华 《海洋科学进展》2007,25(4):474-479

海底沉积物的声学声速特性是沉积物声学中的一个重要的研究方向。正确提取声学原位测量的声速对海底沉积物声学反演至关重要。分析了海底声学原位测试系统的输出子波特性,提出了基于子波提取的互相关双向极值声速提取法。在声速提取过程中,发现某些通道实测声波到达时会出现超出正常范围的异常。分析后认为异常通道的到达波相位出现180°反至现象。通过互相关数值的负极小值提取的声波到达时对互相关正极大值所获得的到达时曲线进行校正后提取声速,得到了正确的结果,说明了本方法的正确性。  相似文献   

Standing crop and primary production of benthic microalgae on tidal flats in the Sanggou and Jiaozhou Bays, China     

Ning Xiuren  Cai Yuming  Liu Zilin  Hu Xigang  Liu Chenggang 《海洋学报(英文版)》2003,22(1):75-87

The standing crop and primary production of benthic microalgae on tidal flats have seasonally been observed in the Sanggou and Jiaozhou Bays of the northern China coast during 1999 - 2000. The results show that the annual primary productions of benthic microalgae on tidal flats in the two bays are 2 532 and 7 542 tons carbon, which would be able to support 3.1 x 103 and 9.2 x 103 tons shellfish meat, respectively. The nature of sediment is essential for governing the biomass and primary production of benthic microalgae on tidal flats. The biomass and primary production of benthic microalgae on tidal flats with muddy sediments are higher than those with sandy sediments, which resulted from higher nutrient concentration and lower grazing pressure. That is the reason why in comparison with Xiangshan Bay the standing crop and production of benthic microalgae on tidal flats of the Sanggou and Jiaozhou Bays are low. Light was a key factor controlling vertical distribution of biomass and production of benthic  相似文献   

海水溶解氧测定方法的研究     

张荣坤  罗颖华  万桢  蔡维平 《海洋学报》1980,2(4):71-85

溶解氧是海洋调查中化学要素部分的重要项目之一。“海洋调查规范”目前仍采用经典的Winkler修正法,由于此方法操作费时,劳动强度大,而且会引起主观误差,因此迫切要求改用仪器分析方法以提高海洋调查工作的质量。  相似文献   

青藏高原羌塘早古生代蛇绿岩——堆晶辉长岩的锆石SHRIMP定年及其意义   总被引：34，自引：7，他引：27  

李才  董永胜  翟庆国  王立全  阎全人  吴彦旺  何彤彤 《岩石学报》2008,24(1):31-36

羌塘中部果干加年山西段发现完整的蛇绿岩组合,由变质橄榄岩、堆晶辉长岩、辉长岩岩墙群、玄武岩、硅质岩等组成。对堆晶辉长岩进行地球化学和定年初步研究,堆晶辉长岩具有洋中脊玄武岩的地球化学特征,获得锆石SHRIMP U-Pb谐和年龄为438±11 Ma,是羌塘地区乃至青藏高原南部首次发现完整早古生代的蛇绿岩。结合角木日地区二叠纪蛇绿岩、双湖以东的晚泥盆世法门期和二叠纪-三叠纪放射虫硅质岩的研究,羌塘中部古特提斯洋盆可能形成于早古生代,持续演化到三叠纪,并且可能是一个连续过程,使我们对青藏高原古特提斯洋的历史及其演化阶段的划分需要重新思考。  相似文献   

GZCORS在广州市某测区地形测量中的应用     

蔡金繁  司顺奇 《现代测绘》2008,31(2):22-23

本文介绍了广州市连续运行参与站系统(GZCORS)和广州市似大地水准面精化成果确立的广州市城市三维定位系统在地形图测量中的应用,并通过实例分析其精度。  相似文献   

一种小波包遥感图像融合方法     

周宏军  李江  蔡志刚 《现代测绘》2008,31(1):35-36

本文介绍了一种基于小波包的遥感图像融合方法,实验采用熵、光谱扭曲指数和边缘指数等作为评价融合质量的定量指标,表明了通过这一融合方法比传统的IHS、PCA、HPF以及小波融合具有更高的光谱信息保持和纹理信息增强能力.  相似文献   

Crop discrimination in Northern China with double cropping systems using Fourier analysis of time-series MODIS data   总被引：4，自引：0，他引：4  

Zhang Mingwei  Zhou Qingbo  Chen Zhongxin  Liu Jia  Zhou Yong  Cai Chongfa 《International Journal of Applied Earth Observation and Geoinformation》2008,10(4):476

Crop identification is the basis of crop monitoring using remote sensing. Remote sensing the extent and distribution of individual crop types has proven useful to a wide range of users, including policy-makers, farmers, and scientists. Northern China is not merely the political, economic, and cultural centre of China, but also an important base for grain production. Its main grains are wheat, maize, and cotton. By employing the Fourier analysis method, we studied crop planting patterns in the Northern China plain. Then, using time-series EOS-MODIS NDVI data, we extracted the key parameters to discriminate crop types. The results showed that the estimated area and the statistics were correlated well at the county-level. Furthermore, there was little difference between the crop area estimated by the MODIS data and the statistics at province-level. Our study shows that the method we designed is promising for use in regional spatial scale crop mapping in Northern China using the MODIS NDVI time-series.  相似文献   

Comment on Was the Indosinian orogeny a Triassic mountain building or a thermotectonic reactivation event? by A. Carter and P.D. Clift [C. R. Geoscience 340 (2008) 83–93]     

Jian-Xin Cai  Xian-Chun Tang  Qing-Guo Wei  Bing Li   《Comptes Rendus Geoscience》2008,340(12):893-895

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