航道疏浚工程竣工验收数字化测量技术研究   总被引：1，自引：0，他引：1  

曾文伟 《测绘信息与工程》2011,36(6):26-28

根据航道疏浚工程竣工验收数字化测量作业流程,阐述了航道疏浚工程竣工验收测量方法和技巧,并借助测量成图软件CASS,绘制航道疏浚工程竣工图,并对绘制过程中的相关技术问题进行了探讨。  相似文献   

深圳铜鼓航道表层沉积物中重金属含量及潜在生态危害   总被引：1，自引：0，他引：1  

李壮伟  陈巧弟  罗荣真  陈鸿生  刘文辉 《海洋地质前沿》2011,(9):32-39

根据2009年9月深圳铜鼓航道表层沉积物中重金属含量的调查资料,采用单因子指数法和Hakanson生态风险指数法对其重金属污染特征及潜在生态风险进行了分析和评价.结果表明:重金属含量较低,属于国家一类海洋沉积物;表层沉积物已受到重金属Pb、Zn、As的污染,所有站住重金属综合污染指数均＞5,达到中等污染水平,各重金属污...  相似文献   

Saari’s conjecture for the restricted three-body problem     

G. E. Roberts  L. Melanson 《Celestial Mechanics and Dynamical Astronomy》2007,97(3):211-223

Saari’s conjecture adapted to the restricted three-body problem is proven analytically using BKK theory. Specifically, we show that it is not possible for a solution of the planar, circular, restricted three-body problem to travel along a level curve of the amended potential function unless it is fixed at a critical point (one of the five libration points.) Due to the low dimension of the problem, our proof does not rely on the use of a computer.  相似文献   

Periodic Orbits in the Restricted Three Body Problem with Radiation Pressure     

A. Elipe  M. Lara 《Celestial Mechanics and Dynamical Astronomy》1997,68(1):1-11

This paper deals with the Restricted Three Body Problem (RTBP) in which we assume that the primaries are radiation sources and the influence of the radiation pressure on the gravitational forces is considered; in particular, we are interested in finding families of periodic orbits under theses forces. By means of some modifications to the method of numerical continuation of natural families of periodic orbits, we find several families of periodic orbits, both in two and three dimensions. As starters for our method we use some known periodic orbits in the classical RTBP. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

Periodic motion around the triangular equilibrium points of the photogravitational restricted problem of three bodies     

C. G. Zagouras 《Celestial Mechanics and Dynamical Astronomy》1991,51(4):331-348

In this article the effect of radiation pressure on the periodic motion of small particles in the vicinity of the triangular equilibrium points of the restricted three body problem is examined. Second order parametric expansions are constructed and the families of periodic orbits are determined numerically for two sets of values of the mass and radiation parameters corresponding to the non-resonant and the resonant case. The stability of each orbit is also studied.  相似文献   

珠江河口磨刀门水道枯季盐水入侵特性分析   总被引：1，自引：0，他引：1  

方神光 《海洋科学》2014,38(11):90-99

为探讨磨刀门水道潮流和盐度的三维分布特性,本文建立了磨刀门水道的三维潮流和盐度数值模型,采用2009年枯季磨刀门水道实测潮流和盐度资料对模型参数进行率定和验证。结果显示,枯季由于上游径流量小,磨刀门水道总体涨、落潮流速都不大,表层总体涨潮平均流速都在0.5 m/s以内,总体落潮平均流速在0.8 m/s以内;底层总体涨落潮平均流速都在0.5 m/s以内;从盐度的平面分布来看,磨刀门水道近口门河段总体呈现涨潮时水道东侧盐度高于西侧,落潮时东侧盐度小于西侧的趋势。大潮和中潮期间,落潮时盐水向上游的入侵距离反而较涨潮时更远,主要原因是,落潮时的底层盐水向上游的补偿流动以及地形阻拦形成更为强烈的紊动扩散。潮汐动力弱(小潮)时,整个水道内水流流速很小,流态平缓,紊动较弱,总体仍呈现涨潮时入侵距离大于落潮,显示枯季磨刀门水道盐水入侵的主要影响因素取决于地形和潮动力。  相似文献   

长江测绘成果管理应用系统研究   总被引：1，自引：0，他引：1  

丁明雷  邹艳红  周冠男  吕霖  桑百川 《测绘科学》2013,38(5):66-68

本文基于地理信息系统和空间数据库技术构建了长江"数字航道"测绘成果管理应用系统的框架体系;在航道测绘基础空间数据库的基础上,开发了航道测绘成果数据管理应用系统,实现了长江中游重点航道的三维模拟分析和中游航道测量调度快速反应与决策分析功能。系统的设计与实现为航道的全面数据管理与测绘成果的进一步应用提供了集成和二次开发平台。  相似文献   

疏浚整治河道对珠江三角洲东平水道上段的影响   总被引：2，自引：1，他引：2  

何晓辉  何建华  车进胜  周作付 《热带地理》2002,22(3):266-269,274

依据详细的实测资料，系统分析了疏浚整治河道对东平水道上段所造成的影响，认为这些影响对于珠江三角洲网河区北江河段具有重要的意义。疏浚整治河道是防治该地区洪患的有效措施之一。  相似文献   

Stable planetary orbits around one component in nearby binary stars. II     

Daniel Benest 《Celestial Mechanics and Dynamical Astronomy》1993,56(1-2):45-50

Numerical simulations are made within the framework of the plane restricted three-body problem, in order to find out if stable orbits for planets around one of the two components in double stars can exist. For any given set of initial parameters (the mass ratio of the two stars and the eccentricity of their orbit around each other), the phase-space of initial positions and velocities is systematically explored.In previous works, systematic exploration of the circular model as well as studies of more realistic (elliptic) cases such as Sun-Jupiter and the nearby Centauri and Sirius systems, large stable planetary orbits were found to exist around both components of the binary, up to distances from each star of the order or more than half the binary's periastron separation.The first results presented here for the Coronae Borealis system confirm the previous studies.  相似文献   

应用Boussinesq方程对由航道开挖所造成水深变化对波浪传播所产生的异常波况的数值研究   总被引：3，自引：2，他引：3  

张永刚  李玉成 《海岸工程》1997,(1)

应用Boussinesq方程采用有限差分法建立了非线性数值波浪模式，并应用该模式对由航道开挖所造成水深变化对波浪传播产生的异常现象进行了数值模拟研究。从结果来看这种异常波浪局部增大现象是由于入射波与航道夹角过小，使波浪无法折射入航道，而在航道两侧反射叠加的结果。因此说水深的变化对波浪产生的反射现象也是不可忽视的。  相似文献