房地产测绘成果质量检查的实践

在介绍房地产测绘流程的基础上,提出不同类型房屋检查的侧重点,总结出房地产测绘成果质量检查的方法.     

关于导线测量中的独立量与相关量

探讨直接观测量与相关量误差传播律的区别.     

适用于不同椭球的高斯平面坐标正反算的实用算法

本文详细介绍了适用于不同椭球的高斯投影正反算公式中子午线弧长或底点纬度的计算方法,并给出了实用公式。该公式简便实用,便于计算机实现。为验证此公式的正确性,本文最后用该公式计算了54椭球子午线弧长及底点纬度计算式中的各系数,与天文大地网推算的相应系数进行了比较验证。     

Vorticity budget investigation of a simulated long-lived mesoscale vortex in South China

A vorticity budget investigation is performed using the output data from a numerical simulation of a typical MCV (mesoscale convectively generated votex) case in South China. Results suggest that the divergence caused by convection in the low troposphere is the main producer of positive vorticity, while vertical vorticity transferred by the tilting term from the horizontal vorticity compensates the upward output of cyclonic vorticity. Scale analyses of the vorticity equation suggest that the advection of planetary vorticity can be neglected owing to the low latitude, which is different from the larger scale systems in high latitude areas. In addition, the distribution of relative vorticity tendency on pressure level is not uniform. A vortex will move along the vector from the negative to the positive vorticity tendency region. The mechanism of the phenomenon-that nearly all of the convectively ascending region is located southward/southeastward of the vortex center-is also discussed. Convergence with regard to latent heat release would be in favor of the spin-up of meso-vortex, however, the horizontal vorticity caused by windshear is tilted by vertical motion due to convection. Consequently, the negative and positive vorticity tendencies are located symmetrically about the convective center, which suggests that the vortex southward movement is dynamically driven by convection.     

关于大地电磁信号非最小相位性的讨论

由于信号的功率谱仅包含振幅信息而不包含相位信息,因此传统功率谱方法仅能处理最小相位信号,难于适用于非最小相位信号．本文对不同地区的实际大地电磁(MT)信号作了分析,结果表明,不同测点MT信号在Z平面上的零点分布并不全部位于单位圆之内,可以判定MT信号一般具有非最小相位的特点,因此有必要改进传统处理方法,发展新的资料处理方式．实际信号分析,理论和数值模型实验证明,信号的高阶统计量包含其相位信息,因此,高阶统计量方法能够有效处理具有非最小相位特征的MT信号．     

粉末压片-X射线荧光光谱法分析富硒土壤样品中的硒及主次量元素

目前土壤中Se主要采用原子荧光光谱法测定,存在用酸量大、前处理相对复杂等缺点,对于高含量Se的测定则需要高倍稀释,无疑会扩大分析误差.本文采用粉末压片波谱-能谱复合X射线荧光光谱法测定湖北富硒土壤样品中的Se等17个主次量元素,波谱分析10个元素的同时,能谱分析As、Cu、Rb、Sr、Zr、Ba、Ni等7个元素,大幅节...     

An analysis of the radar backscatter from oil-covered sea surfaces using moment method and Monte-Carlo simulation: preliminary results

An analysis of the radar backscattering from the ocean surface covered by oil spill is presented using a microwave scattering model and Monte-Carlo simulation. In the analysis, a one-dimensional rough sea surface is numerically generated with an ocean waveheight spectrum for a given wind velocity. A two-layered medium is then generated by adding a thin oil layer on the simulated rough sea surface. The electric fields backscattered from the sea surface with two-layered medium are computed with the method of moments (MoM), and the backscattering coefficients are statistically obtained with N independent samples for each oil-spilled surface using the Monte-Carlo technique for various conditions of surface roughness, oil-layer thickness, frequency, polarization and incidence angle. The numerical simulation results are compared with theoretical models for clean sea surfaces and SAR images of an oil-spilled sea surface caused by the Hebei (Hebei province, China) Spirit oil tanker in 2007. Further, conditions for better oil spill extraction are sought by the numerical simulation on the effects of wind speed and oil-layer thickness at different incidence angles on the backscattering coefficients.     

黄河清水沟叶瓣水下三角洲演变过程

对黄河口30多年来的叶瓣演变过程进行了详细研究。利用遥感假彩色合成解译历年岸线和流路河道变化,利用1976—2005多年的水深数据,定量分析了清水沟叶瓣水下三角洲堆积体不同时段的冲淤变化过程。将水下三角洲堆积体的演变过程划分为4个阶段,即多淤积中心阶段→单一稳定淤积阶段→缓慢淤积阶段→淤积—侵蚀同时发生阶段,证明黄河口三角洲堆积体演变过程对流路演化的阶段性有很好的响应关系。同时对清水沟水下三角洲演化的影响因素进行了分析。     

浮式油气生产储卸装置风倾力臂解析解及相关线性关系研究

为了建立驳船型浮式生产储卸装置的风倾力臂和船型参数之间的函数关系,构造了与其主尺度及设计工况对应吃水、排水量和正浮状态侧向所受风倾力臂相关的3个无因次量——"相对力臂"、"相对排水量"和"相对吃水",使前二者的乘积与相对吃水呈现出线性变化关系,通过拟合直线得到风倾力臂的解析解,其有效性经6艘我国现役FPSO的设计数据和理论分析验证,结果理想。     

桂林会仙岩溶湿地典型水生植物δ13C特征与固碳量估算

为促进目前岩溶碳汇稳定性和速率等科学问题的深入研究,在分析桂林会仙岩溶湿地主要水生植物碳同位素的基础上,利用基于碳酸酐酶活性与植物碳同位素值显著正相关的二端元模型,估算了不同植物利用光合作用固定HCO3-的比例。结果表明,湿地核心区沉水植物光合作用固定HCO3-碳量在4.86~64.73 tC/（a?km2）之间,挺水植物为15.68~453.01 tC/（a?km2）,平均值为76.74 tC/（a?km2）。按平均值计算会仙湿地水生植物光合作用固定HCO3-碳量为4 466.27 tC/a,即在会仙湿地岩溶地下河补给的HCO3-中约47 %被水生植物光合作用固定。水生植物光合作用固碳效果明显,是碳汇研究中不容忽视的一个十分重要的问题。