赤潮藻的显微图形测量方法研究   总被引：2，自引：0，他引：2  

徐雷  于连生 《海洋技术学报》2003,22(3):43-46

介绍了一种在实验室环境下通过显微镜及CCD成像的办法观察采集微小藻类图像，并通过计算机软件进行图像识别统计，最终得到所测藻类统计信息的方法。  相似文献   

大鹏湾夜光藻种群的季节变化和分布特征   总被引：2，自引：0，他引：2  

黄长江  齐雨藻  杞桑  吕颂辉  江天久 《海洋与湖沼》1996,27(5):493-498

于1990年3月－1992年6月对中国南海大鹏湾盐田附近海域的夜光藻种群动态及时空分布进行综合调查。结果表明，夜光藻种群的出现期间一般为每年的1－6月，最早是1991年的12月，数量高峰期为3－5月，种群密度的波动极为显著；调查期间共发生8次赤潮，且都发生在3月初至5月初；大鹏湾夜光藻赤潮的发生特点是，赤潮的发生和消失突然，持续时间短，一般不超过3d；调查海域夜光藻种群的空间分布模式为近岸的高于中央水域的，表面的高于底层的。  相似文献   

基于单调链的Red/Blue扫描线求交算法   总被引：3，自引：0，他引：3  

杨崇俊  任应超  李津平 《武汉大学学报(信息科学版)》2006,31(9):835-838

提出了一种基于单调链的Red／Blue平面扫描线算法。该算法针对GIS中线段之间具有连接关系的特性，将平面连接线段集分解为一组单调链，通过对单调链的粗扫描过滤和对线段的精扫描求交，减少了扫描过程中的冗余计算，提高了线段集求交点的效率。实验证明，该算法对于处理具有连接关系的线段集的求交点问题具有很高的效率。  相似文献   

WATER POLLUTION IN THE RIVER MOUTHS AROUND BOHAI BAY   总被引：10，自引：0，他引：10  

Cheng LIU  Zhao-Yin WANG  Yun HE Dr.  Asso. Prof.  International Research  Training Center on Erosion  Sedimentation  Beijing .China  Prof.. Dept. of Hydraulic Engineering  Tsinghua University & International Research  Training Center onErosion  Sedimentation  Beijing    China.China Institute of Water Resources  Hydropower Research. Beijing  China 《国际泥沙研究》2003,18(4)

Twelve water samples were collected and analyzed. The samples were taken from the river mouths around Bohai Bay including the Jiyun. New Yongding, Haihe, Dagu, Duliujian, Qingjinghuang, Qikou, Dakou, and Yellow Rivers, and tested for concentrations of heavy metals, arsenic, total nitrogen (TN) and total phosphorus (TP). The results show that the river mouths are polluted and the water quality exceeds Class V of the Environmental Quality Standard for Surface Water (EQSSW). The main pollutants are Hg, nitrogen (N) and phosphorus (P). The concentrations of the other pollutants are within Class II of the Standard. The Hg content in the Haihe River mouth is now 10 times higher than it was 20 years ago, indicating that the accelerating water pollution has reached an alarming level. The high concentrations of N and P cause eutrophication of the waters. Analysis indicates that the terrestrial pollutants and nutrients are the main cause of frequently occurring red tides in the Bohai Sea.  相似文献   

红层M形路堑边坡特征及病害的初步研究   总被引：2，自引：4，他引：2  

朱宝龙  胡厚田  陈强 《工程地质学报》2003,11(4):411-415

在对红层地区渝綦、綦万高速公路路堑边坡调查的基础上,提出了M形路堑边坡的概念,并总结了其特点;简要分析了红层和坡残积层物质的岩土矿物成分和结构特征,探讨了红层M形路堑边坡病害发生的类型及形成原因,为边坡稳定性评价与采取合理的边坡加固措施提供了依据。  相似文献   

EARTHQUAKE FOCAL MECHANISM AND ITS TECTONIC SIGNIFICANCE ALONG THE TWO SIDES OF THE RED RIVER FAULT ZONE   总被引：1，自引：0，他引：1  

ZHU Junjiang~*  ZHAN Wenhuan  QIU Xuelin  XU Huilong  TANG Cheng 《大地构造与成矿学(英文版)》2004,28(1):79-92

The Red River Fault Zone is a gigantic slide-slip fault zone extending up to 1000km from Tibet to South China Sea. It has been divided into the north, central and south segments according to the difference of the geometry, kinetics, and seismicity on the land, but according to the contacted relationship between the old pre-Cenozoic block in Indochina Peninsula and the South China block, the Red River Fault Zone was divided into two parts extending from land to ocean, the north and south segments. Since the Tertiary, the Red River Fault Zone suffered first the sinistral movement and then the dextral movement. The activities of the north and the south segments were different. Based on the analysis of earthquakes and focal mechanism solutions, earthquakes with the focus depths of 0-33km are distributed over the whole region and more deep earthquakes are distributed on the northeastern sides of the Red River fault. Types of faulting activities are the thrust in the northwest, the normal in the north and the  相似文献   

Biostratinomy and facies analysis of the upper Cretaceous oyster storm shell beds of the Duwi formation, Qusseir District, Red Sea Region, Egypt     

Abdalla M. El-Ayyat  Ahmed S. Kassab 《Journal of African Earth Sciences》2004,39(3-5):421

The Maastrichtian oyster Lopha villei (Coquand) occurs abundantly in the upper part of the Duwi Formation in the Red Sea region, Egypt. It forms thin undulating sharp-based shell beds that comprise both reclining and encrusting morphotypes of Lopha villei. Bed-by-bed biostratinomic and facies analyses of these shell beds confirm their shallow marine origin and formation by storm events. A tempestite model, explaining the mode of formation and the idealized sequence of events of such storm shell beds, has been inferred.  相似文献   

水分胁迫下棉花冠层叶片氮素状况的高光谱估测研究   总被引：4，自引：3，他引：4  

马亚琴  包安明  王登伟  孙莉  黄春燕  冯宪伟  肖春华  杨新军 《干旱区地理》2003,26(4):408-412

在不同灌水量条件下，对棉花单叶叶绿素含量和单叶全氮含量做相关分析，并采用地物光谱仪。获取北疆棉花冠层关键生育时期的高光谱数据。应用一阶微分光谱，衍生出基于光谱位置变量的分析方法。以红边积分面积(SDr)为白变量，冠层全氮(TN)含量为因变量，做相关分析。结果表明：叶绿素含量与TN含量呈显著的正相关(R=0．8723^**。n=39)，叶绿素含量能有效的估计棉花单叶TN含量；红边积分面积变量与冠层TN含量呈显著的相关性，相关系数是0．7394^**(n=40)，利用构建的相关模型可以较为精确地估测新陆早6号、8号冠层叶片的全氮含量，RMSE分别为0．3859和0．4272。研究认为红边积分面积变量具有预测棉花冠层全氮含量的应用潜力。  相似文献   

Holocene Coastal Stratigraphy and the Sedimentary Development of the Hai Phong Area of the Bac Bo Plain (Red River Delta), Vietnam     

DOAN DINH LAM  W. E. BOYD 《The Australian geographer》2003,34(2):177-194

We report a study of the Holocene coastal sediments of the Hai Phong area of the Bac Bo Plain (also known as the Red River Delta) in northern Vietnam. This is the first attempt to interpret the region's coastal depositional environments in the light of a geological model of Holocene environmental change recognising the interacting roles of Holocene sea-level change, alluvial responses to sea-level fluctuation, and tidal environment sedimentation. The coastal sediments overlie a Pleistocene land surface, and represent the Holocene marine transgression and regression. Prior to c .6000 bp , the sea rose to around or above its present elevation, converting the Pleistocene terrestrial landscape to a Holocene tidal landscape of tidal flat, channel and mangrove environments. Sea-level lowering by c .4000 bp triggered a switch in dominant sedimentary processes, allowing floodplain sediments to be deposited increasingly seawards.  相似文献   

Optical emission at 5800 Å in the Red Rectangle and the 5797-Å diffuse interstellar band     

W. W. Duley 《Monthly notices of the Royal Astronomical Society》1998,301(4):955-959

An analysis of the intensity and spatial distribution of the discrete 5800-Å emission band in the spectrum of the Red Rectangle has been used to constrain the abundance and physical properties of the carrier of this emission. An origin in a large (>30 C atom) molecule is indicated. This molecule is formed in situ in the Red Rectangle, but is also a component of the diffuse interstellar medium. The UV photodissociation probability for this molecule is ≲10⁻⁵ per absorbed photon, and the luminescence efficiency is in the range 10⁻²–10⁻³. This molecule may be a product of the dissociation of carbonaceous dust.  相似文献