7.24局地暴雨的雷回波及天气成因分析

分析了１９９７年７月２４日哈尔滨市暴雨的天气背景。利用雷达回波着重分析在中尺度系统影响下产生的强对流天气及降水时间和落区,解释了没有产生冰雹的原因。     

鲎:比恐龙还老的海鱼

外表的色彩是棕色的,长相既像虾又像蟹,所以人们又称鲎为“马蹄蟹”。它是和三叶虫(现在只有化石)一样古老的动物。鲎的祖先出现在地质     

浅议土地整理复垦开发项目中的政府行为——以湖南省为例

随着土地整理复垦开发各项改革制度的深入，在一定的历史条件下形成的单一部门行业管理行为越来越难适应土地整理复垦开发项目发展的需要。通过对土地整理复垦开发相关概念的界定，分析了单一部门行业管理形成产生的各种原因并指出其存在的各种弊端，并根据未来土地整理复垦开发行业发展的趋势，论证了在土地整理复垦开发项目管理过程中将单一的部门行业管理行为上升为政府行为的合理性。     

探地雷达在探测岩溶中的应用

介绍了探地雷达的基本原理，总结出雷达波在不同介质中的传播特性。并通过工程实例证明了探地雷达探测岩溶的可行性和有效性。     

洛阳市强力推进第二次土地调查

2007年以来,洛阳市按照"数据准确、工作一流、保障有力、整体推进"的工作思路,科学谋划,精心组织,强力推进,确保了第二次土地调查工作的顺利进行。     

不能以投影土地面积计算征地补偿

新增建设项目用地需要对土地所有者进行征地补偿。征地补偿费是根据土地利用类型、被征土地面积和单位土地面积补偿标准计算的。征地工作中,经常因土地面积问题引发土地补偿纠纷。信访工作中,经常有上访者质询土地面积的测算方法问题,上访者都要求按实际土地面积为标准计算征地补偿。笔者认为征地补偿土地面积的计算方法确实值得商榷。     

吕宋海峡M2内潮的三维数值模拟

A three-dimensional isopycnic-coordinate internal tidal model is employed to investigate the generation,propagation, vertical structure and energy conversion of M2 internal tides in the Luzon Strait(LS) with mooring observations. Simulated results, especially the tidal current amplitudes, agree well with observations,demonstrating the reasonability and accuracy of the model. Results indicate that M2 internal tides mainly propagate into three directions horizontally, i.e., eastward towards the western Pacific Ocean, westward towards the Dongsha Island and southwestward towards the South China Sea Basin. In the horizontal direction, tidal current amplitudes decrease as distance increases away from the LS; in the vertical direction, they show an obvious decreasing tendency with depth. Between the double ridges of the LS, a clockwise gyre of M2 baroclinic energy flux appears, which is caused by reflections of M2 internal tides at supercritical topographies, and resonance of M2 internal tides happens along 19.5° and 21.5°N due to the heights and separation distance of the double ridges. The total energy conversion in the LS is about 14.20 GW.     

黄河口海底液化粉土特征研究

选取黄河口埕岛油田海域作为研究区,在先前调查研究工作的基础上对该区域海底液化粉土特征进行研究,从声学特征、物理力学参数特征、微结构特征以及动三轴试验分析这4个方面详细分析了液化粉土与未液化粉土的性质差异。研究表明,液化粉土的物理力学性质相对于未液化粉土有着明显的变化,液化粉土的标贯击数值较未液化粉土增加,在相同的振次条件下,液化粉土的抗液化剪应力比比未液化粉土大,土的抗液化强度增加,液化粉土较未液化粉土更难发生液化。     

宗海图编绘的几个关键问题探讨

宗海图是海域使用权证书和宗海档案的主要附图,是申明海域使用权属的重要依据,考虑到宗海图编绘的重要性,文章通过分析当前海域使用项目宗海图编绘中存在的坐标系、界址点精度和面积量算等问题进行探讨,以此期望促进海域使用项目宗海图绘制的规范化和海域使用管理工作的科学化。     

Nonlinear Dynamic Behaviors of A Floating Structure in Focused Waves

Floating structures are commonly seen in coastal and offshore engineering. They are often subjected to extreme waves and, therefore, their nonlinear dynamic behaviors are of great concern. In this paper, an in-house CFD code is developed to investigate the accurate prediction of nonlinear dynamic behaviors of a two-dimensional (2-D) box-shaped floating structure in focused waves. Computations are performed by an enhanced Constrained Interpolation Profile (CIP)-based Cartesian grid model, in which a more accurate VOF (Volume of Fluid) method, the THINC/SW scheme (THINC: tangent of hyperbola for interface capturing; SW: Slope Weighting), is used for interface capturing. A focusing wave theory is used for the focused wave generation. The wave component of constant steepness is chosen. Comparisons between predictions and physical measurements show good agreement including body motions and free surface profiles. Although the overall agreement is good, some discrepancies are observed for impact pressure on the superstructure due to water on deck. The effect of grid resolution on the results is checked. With a fine grid, no obvious improvement is seen in the global body motions and impact pressures due to water on deck. It is concluded that highly nonlinear phenomena, such as distorted free surface, large-amplitude body motions, and violent impact flow, have been predicted successfully.