一级检查在航测外业调绘中的应用与探讨     

饶洪全 《东北测绘》2014,(1):206-208,212

结合工作实践,主要探讨了一级检查在1：5000及1：10000航测外业调绘工作中的应用,并对如何提高产品质量做一定的思考和研究。  相似文献   

建设工程基础验线与竣工规划测量的研究     

黄心一  陶利  秦政国 《现代测绘》2014,(4):11-13

基础验线与竣工规划测量是城市规划管理的重要环节,其成果是规划过程监督管理与竣工验收审核的重要依据。无锡市自2012年1月1日起正式实施建设工程基础验线与竣工规划测量工作。本文介绍了无锡市建设工程基础验线与竣工规划测量的作业依据与资料准备、工作内容及提交的成果,并结合工程实例对成果进行分析,为今后工作提供参考。  相似文献   

Empirical formula for wave length of ocean wave in finite depth water     

管长龙  鞠红梅 《中国海洋湖沼学报》2005,23(1):17-21

In this paper, function characteristics of dispersion of ocean wave in finite depth water were analyzed systematically. The functional form of the fitting function is reasonably proposed, in which the parameters are optimally determined by the least square method （LSM）. For infinitely deep and extremely shallow water,the fitting function fits strictly the dispersion to be fitted. A new technique is presented in application of LSM.An empirical formula with maximum error of less than 0.5% for computing wavelength in finite depth water is presented for practical applications.  相似文献   

通海台垂直摆受建筑载荷影响的数值模拟研究     

岳冲  李利波  闫伟  洪敏 《大地测量与地球动力学》2022,42(9):985-990

针对通海台垂直摆NS和EW测项自2019-04出现同步趋势转折变化,计算2017~2020年NS和EW测项M₂波潮汐因子。结合监测井等地下介质结构资料,构建通海台沿垂向分层的三维有限元物理模型,定量分析不同岩石参数模型下建筑载荷对通海台NS向及EW向位移影响的差异特征。结果表明：1）2019-04后NS测项N倾变化量达到约2 750 ms,而EW测项E倾变化量达到约580 ms,NS测项趋势变化量显著大于EW测项;2）2017~2020年NS和EW测项M₂波潮汐因子较为稳定,NS测项M₂波潮汐因子在0.7左右波动,EW测项M₂波潮汐因子在0.52左右波动,数据的转折变化未能在潮汐频段引起同步变化;3）位于通海台东北部的医院建筑物载荷在通海台附近产生N向和E向位移加载,与垂直摆NS和EW测项在2019-04后出现的N倾和E倾趋势转折变化较为一致,模拟得到的N向位移量约为E向位移量的3倍。  相似文献   

热源强迫的非线性惯性重力内波及其应用     

吴俞  李国平 《成都信息工程学院学报》2006,21(Z1):7-11

利用动力学分析中的相平面方法,由z坐标系下的非绝热大气运动方程组导出了与非线性惯性重力内波有关的KdV方程,然后利用直接积分法得到两类有天气意义的孤立波解.初步建立了孤立波解与高原低涡的联系,进一步从理论上论证了高原低涡具有与热带气旋类低涡类似的涡眼和暖心结构的特征.  相似文献   

Analysis on monthly-averaged distribution of sea surface wind and wave over the seas southeast of Asia using ERS-2 scatterometer data     

赵喜喜  侯一筠  李明悝  齐鹏 《中国海洋湖沼学报》2006,24(1):97-102

The wind system over the seas southeast of Asia (SSEA) plays an important role in China's climate variation. In this paper, ERS scatterometer winds covering the period from January 2000 to December 2000 and the area of 2-41 °N, 105- 130°E were analyzed with a distance-weighting interpolation method and the monthly mean distribution of the sea surface wind speed were given. The seasonal characteristics of winds in the SSEA were analyzed. Based on WAVEWATCH Ⅲ model, distribution of significant wave height was calculated.  相似文献   

Scattering of elastic wave by a partially sealed cylindrical shell embedded in poroelastic medium     

Liu Gan‐Bin  Xie Kang‐He  Yao Hai‐lin 《国际地质力学数值与分析法杂志》2005,29(11):1109-1126

Scattering of an elastic wave by a cylindrical shell embedded in poroelastic medium is investigated theoretically with the assumption that the shell material is also a porous elastic medium. The porous medium is modellized via Biot's theory and the scattering by cylindrical shell is expressed by the definition of scattering matrix. The normal mode expansion technique is employed for analysing the scattering field, and the asymptotic solutions of displacements, stresses and pore pressure are derived. Two limiting cases‐scattering by a poroelastic cylinder in Biot medium and a elastic cylindrical shell in elastic medium are obtained from the general solutions. The dispersion curves of displacement amplitude at the interface of shell and medium is compared with the case of elastic shell. The scattering amplitude associated with the fast, slow and transverse waves are identified by numerical simulation. Furthermore, the influence of the poroelastic property of shell material on scattering amplitude is analysed. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

A local control system for the test masses of the Virgo gravitational wave detector     

《Astroparticle Physics》2004,20(6):617-628

The mirrors of interferometric detectors of gravitational waves (GW) are suspended in order to be isolated from external disturbances. A local control system able to keep them correctly aligned and to damp the angular modes of the suspension is necessary. In this paper we present the solution adopted for Virgo based on a CCD camera sensor and on digital controls. With this solution the mirrors are kept aligned at the level of less than 1 μrad rms, enough to lock the interferometer and start the automatic alignment system.  相似文献   

Effect of the duration and direction of storm movement on infiltrating planar flow with full areal coverage     

V. P. Singh 《水文研究》2002,16(7):1479-1511

Using kinematic wave equations, analytical solutions are derived for flow due to a storm moving up or down an infiltrating plane and covering it completely. The storm duration is assumed in two ways. First, the plane is covered everywhere for the same duration by the storm. Second, the plane is covered in a linearly decreasing manner from the beginning of its coverage of the plane to the other end of the plane. By comparing the flow due to this storm with that due to a stationary storm of the same duration, the influence of storm duration, direction and velocity on flow hydrograph is investigated. It is found that storm movement has a pronounced effect on runoff hydrograph. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

Inbank and overbank velocity conditions in an arid zone anastomosing river     

A. David Knighton  Gerald C. Nanson 《水文研究》2002,16(9):1771-1791

Relative to those at sub‐bankfull flow, hydraulic conditions at overbank flow, whether in the channel or on the floodplain, are poorly understood. Here, velocity conditions are analysed over an unusually wide range of flows in the arid zone river of Cooper Creek with its complex system of anastomosing channels and large fluctuations in floodplain width. At‐a‐station hydraulic geometry relationships reveal sharp discontinuities in velocity at the inbank–overbank transition, the nature of the discontinuity varying with the degree of flow confinement and the level of channel–floodplain interaction. However, despite inter‐sectional differences, velocities remain modest throughout the flow range in this low‐gradient river, and the large increases in at‐a‐station discharge are principally accommodated by changes in cross‐sectional area. Velocity distribution plots suggest that within‐channel conditions during overbank flow are characterized by a central band of high velocity which penetrates far toward the bed, helping to maintain already deep cross‐sections. Floodplain resistance along Cooper Creek is concentrated at channel bank tops where vegetation density is highest, and the subsequent flow retardation is transmitted across the surface of the channels over distances as large as 50–70 m. The rough floodplain surface affects flood wave transmission, producing significant decreases in wave speeds downstream. The character of the wave‐speed–discharge relationship also changes longitudinally, from log–linear in the upper reaches to nonlinear where the floodplain broadens appreciably. The nonlinear form is similar in several respects to relationships proposed for more humid rivers, with flood wave speed reaching an intermediate maximum at about four‐fifths bankfull discharge before decreasing to a minimum at approximately Q_2·33. It does not regain the value at the intermediate maximum until the 10 year flood, by which time floodplain depths have become relatively large and broad floodways more active. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献