GBSAR和三维激光扫描技术提取DEM应用研究

分析了星载SAR和GBSAR提取DEM的原理,利用GBSAR干涉影像提取目标区域的DEM,并将得到的DEM与三维激光扫描数据得到的精细DEM模型进行对比和统计分析。实验结果表明,GBSAR提取的DEM与三维激光扫描提取的精细DEM大体一致,且误差在较小的范围内,满足DEM提取精度要求,说明GBSAR提取目标区域的DEM是可行的,为GBSAR的推广应用奠定了基础。     

关于网络用户经济效益评测模型的研究

着重讨论了网络用户经济效益的内涵以及用户的投入量和产出量，并提出了评价网络用户经济效益的指标体系，包括成本降低率，成本利润增长率、产品开发时间约率、市场占有增长率等系列指标。     

关于网络企业经济效益的评价理论研究

网络经济是相对于大工业经济而言的，其网络企业经济效益的评价，可以从网络企业成本及收益两个方面讨论，然后以投入产出比等五个方面来建立其评价指标体系。     

Modified PIC Method for Sea Ice Dynamics

The sea ice cover displays various dynamical characteristics such as breakup, rafting, and ridging under external forces. To model the ice dynamic process accurately, the effective numerical modeling method should be established. In this paper, a modified particle-in-cell （PIC） method for sea ice dynamics is developed coupling the finite difference （FD） method and smoothed particle hydrodynamics （SPH）. In this method, the ice cover is first discretized into a series of lagrangian ice particles which have their own sizes, thicknesses, concentrations and velocities. The ice thickness and concentration at Eulerian grid positions are obtained by interpolation with the Gaussian function from their surrounding ice particles. The momentum of ice cover is solved with FD approach to obtain the Eulerian cell velocity, which is used to estimate the ice particle velocity with the Gaussian function also. The thickness and concentration of ice particles are adjnsted with particle mass density and smooth length, which are adjusted with the redistribution of ice particles. With the above modified PIC method, numerical simulations for ice motion in an idealized rectangular basin and the ice dynamics in the Bohai Sea are carried out. These simulations show that this modified PIC method is applicable to sea ice dynamics simulation.     

三种高程传递方法的精度分析

通过试验对悬挂钢尺、GPS测高和全站仪垂直测高三种高程传递方法进行了理论分析与精度比较,并讨论了各种方法在实际应用中的优点与局限性。     

筑脉聚魂促发展——滦河迁安市段生态防洪工程纪实

有人说，水为城之魂，路为城之脉，而滦河迂安市段生态防洪工程兼而据之——该市于2003年4月份开工建设的滦河迂安市段生态防洪工程集防洪、生态、城市建设三大效益于一体，其整体效益日益凸现。     

Experimental Study on Mine Spoils During Superficial Geochemistry Processes

Based on the mineral and chemical compositions of spoils taken from the Shilu Cu-Mo deposit and Hetai gold deposit, the leaching and batch experiments were made on spoils taken from these two deposits using the leaching column designed by the authors. The experimental results showed that it is not always true that the mine drainage is acidic. Its acidity depends on acid-buffering capacity of gangue, host rock and its alteration mineral assemblage. The composition of the drainage water is related with the interaction between superficial or underground water and solid materials in the spoils, including minerals, hydroxides and amorphous substances. The leaching extent of the element is related with its occurrence form in the deposit. The preferential flow results in leaching-out of heavy metals in large amounts. So it is important to prevent the generating of preferential flow in the system. The results will provide very important grounds for the comprehensive management of land and ecological rehabilitation of the mine site.     

配制日照纸感光药剂的简便方法

经调查 ,大部分气象台站使用混合涂药法配制日照纸感光药剂。《地面气象观测规范》(以下简称《规范》)中有关混合涂药法的叙述是 :赤血盐与水的比例是 1∶1 0 ,枸橼酸铁铵与水的比例为 3∶1 0。按此比例用两个容器分别配制好药液 ,将已配制好的两种药液等量混合在一起 ,搅匀 ,然后按要求进行涂刷。该方法需要 3个容器和 1架天平 ,分别称量各种物质 6次 ,步骤较为繁琐。我局测报人员在实践中总结出一种较为简便的方法。1　药品比例分析从《规范》中可以知道 ,赤血盐在赤血盐溶液中所占的比例为1 / 1 1 ,枸橼酸铁铵在枸橼酸铁铵溶液中所占的比…     

地铁隧道复杂洞群施工性态三维数值模拟分析

深圳地铁大～科区间渡线隧道工程是一个结构极为复杂的洞群系统工程问题,由于地质条件差且周围环境条件限制严格,施工难度和风险极大,文中对该实际工程进行了施工优化分析,建立了复杂的三维有限元计算模型,并对该工程的施工过程进行了三维弹塑性仿真分析,取得了一些有意义的成果,工程实践表明,文中的分析结果是合理可靠的.