Rheological Properties and Incipient Motion of Cohesive Sediment in the Haihe Estuary of China   总被引：2，自引：1，他引：2  

BAI  Yu-chuan 《中国海洋工程》2002,16(4):483-498

The Haihe cohesive sediment, which is typical in China, is studied systematically for its basic physical and incipientmotion properties. Following the requirements of dredging works in the Haihe Estuary, cohesive sediment samples weretaken from three locations. Laboratory experiments were conducted to determine the rheological properties of these sam-ples and to examine the incipient motion of the cohesive sediment. It is found that the cohesive sediment has an obviousyield stress τb, which increases with the mud density in a manner of an exponential function, and so does the viscosityparameter η. The cohesive sediment behaves like a Bingham fluid when its density is below 1.38 ～ 1.40 g/cm3, andwhen denser than these values, it may become a power-law fluid. The incipient motion experiment also revealed that theincipient velocity of the cohesive sediment increases with the density in an exponential manner. Therefore, the incipientmotion is primarily related to the density, which is different from the case for non-cohesive sediment in which the incipi-ent motion is correlated with the diameter of sand particles instead. The incipient motion occurs in two different ways de-pending on the concentration of mud in the bottom. For sufficiently fine particles and a concentration lower than1.20 g/cm3, the cohesive sediment appears as fluidized mud, and the incipient motion is in the form of instability of aninternal wave. For a higher concentration, the cohesive sediment appears as general quasi-solid-mud, and the incipientmotion can be described by a series of extended Shields curves each with a different porosity for newly deposited alluvial mud.  相似文献   

A Numerical Study on the Structure and Dynamics of Turbulence in Oscillatory Bottom Layer Flow over A Flat or Rippled Bed     

白玉川  吴朝安黄涛 《中国海洋工程》2006,20(1):45-60

1 .IntroductionUnder the influence of surface waves ,sandripples often appear on beaches . Whenthe amplitudeof water oscillationis sufficientlylarge ,vortices are formed onthe lee of every sand ripple crest . A-mongthese vortices ,the most important are t…  相似文献   

高效液相色谱法测量青海湖浮游植物色素浓度     

朱建华  伍慧敏  周虹丽  汪小勇 《海洋技术学报》2005,24(2):46-49,54

2003年8月，我们利用高效液相色谱法(HPLC)对浮游植物色素进行分类定量分析。结果表明青海湖的叶绿素类以叶绿素a和b为主，叶绿素a浓度最高；光合作用类胡萝卜素种类极少，浓度很低；光保护色素种类较多，浓度较高，其中以Zea，Diadino，β．β-Car和Viola为主。  相似文献   

我国部分市郊农田的重金属污染与防治途径   总被引：12，自引：2，他引：12  

胡宁静  李泽琴  黄朋  程温莹 《矿物岩石地球化学通报》2003,22(3):251-254

分析了我国部分主要城市农田土壤及农作物重金属污染状况，以了解土壤中与农作物中重金属污染物间的相互关系、变化趋势及造成污染的影响因素。结果表明，我国各大城市的农田土壤及农作物都存在不同程度的重金属污染，北方地区的土壤及农作物受重金属污染程度普遍高于南方。重金属在农作物与土壤中的含量一般呈正相关关系，受多种因素影响。对于已污染的土壤，可采用农业工程措施、生物修复法和施用改良剂等予以治理。  相似文献   

Spatial and Genetic Relationships of Groove Belts,Rift Zones,and Lobate Plains on Venus     

Guseva  E. N. 《Solar System Research》2019,53(3):151-160

Solar System Research - Relationships of two types of extensional zones formed on the surface of Venus in different periods of geologic history—older groove belts and younger rift...  相似文献   

Spatiotemporal Relationships of the Groove Belts,Coronal Structures,and Rift Zones of Venus     

Guseva  E. N.  Ivanov  M. A. 《Solar System Research》2019,53(6):411-422

Solar System Research - We have analyzed the spatial and age relationships of volcano-tectonic units that have developed on the surface of Venus: groove belts, coronae, and rift zones. Most of the...  相似文献   

Autonomous (Non-Plate-Tectonic) Geodynamics of the Pyrenees     

Shevchenko  V. I.  Guseva  T. V.  Dobrovolsky  I. P.  Krupennikova  I. S.  Lukk  A. A. 《Izvestiya Atmospheric and Oceanic Physics》2018,54(8):826-847

Izvestiya, Atmospheric and Oceanic Physics - The tectonic structure, seismicity, and modern geodynamics of the roughly EW-trending Pyrenees are considered based on the literature data. Geological...  相似文献   

Thermomechanical mathematical model of the formation of the structure and properties of snowpack     

E. Guseva  V. Golubev 《GeoJournal》1989,19(2):193-200

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地图可视化   总被引：5，自引：1，他引：5  

张燕燕  胡毓钜 《测绘工程》2001,10(1):27-29,36

从科学计算可视化和现代地图学的发展中，介绍了当今地图学研究中的热点问题－－地图可视化。认为在地图学的研究中，应重视由可视化技术带来的新的生长点，从而指导对虚拟地图、动态地图、交互地图、基于万维网地图的制作原理和方法的建立。  相似文献   

GPS定位技术在高层建筑施工基准传递中的应用   总被引：4，自引：0，他引：4  

黄声享  柳响林 《测绘工程》2001,10(1):37-40

在高层建筑施工中，基准传递是一项极为重要的测量工作，为了满足现代建筑工程快速、高效、优质的施工需要，文中提出应用GPS定位技术实施施工基准定位的方法，并结合工程实测就作业过程作了阐述。结果表明，在超高层建筑的基准传递中，应用GPS是一种行之有效的新方法。  相似文献