光电测距仪精测尺频率校准方法与仪器的研究

本文介绍现今光电测距仪精测频率测量的六种测量原理，方法及相应的测量仪器－EFC系列光电测距仪频率校准仪．     

机载POS系统中惯性测量单元精度检校方法

本文简要介绍了GPS/INS组合技术的优势和特点,分析了惯性测量单元(IMU)的工作原理及精度影响因素,系统阐述了机载POS系统中IMU的检校方法和精度评定方法,包括初始对准重复性检测、跟踪姿态角精度的标定和静态漂移检测等,并利用双轴数控转台,对3台不同类型的国产POS系统进行了数据采集、处理和对比分析,实验初步表明,...     

隧道施工断面快速测量方法

在隧道施工断面测量过程中,在最小投入的前提下,采用极坐标法能够及时为施工提供可靠的测量数据,准确地指导断面施工。而三维坐标段落法,只需测量任意点的三维坐标即可计算其偏差,全面地反映整个段落任意桩号各个点的超欠挖情况。     

自由设站在数字测图中的运用

本文探讨了在暂无控制点成果、控制点间不能通视等情况下,运用全站仪自由设站法进行测量工作以及数据换算的方法。     

测量学教学中钢尺精密量距计算问题讨论

一些文献及在教学过程中有学生对测量学教材中钢尺精密量距计算公式提出了疑问，本文针对这些疑问进行讨论，并给出了一些教学中的建议。     

Use of measurement uncertainty in a probabilistic scheme to assess compliance of bottled water with drinking water standards

Ground water bodies are important resources for drinking water, including bottled water, and national regulatory bodies should assess their quality continuously. For this purpose, an effective assessment system of bottled water at source should be installed. A hierarchical nested balance design for the collection of random primary duplicate water samples, and their replicate analyses, is described, and the use of robust analysis of variance to estimate measurement uncertainty. The latter is subsequently used for the development of four probabilistic categories for the classification of element concentrations in bottled water with respect to legislative standard values, i.e., (a) compliant (below Lower Threshold Limit), (b) possibly non-compliant (possibly above Standard Value), (c) probably non-compliant (probably above Standard Value), and (d) non-compliant (above Upper Threshold Limit), for the reliable assessment of compliance to European Union and national drinking water standards. Overall, the quality of European bottled water is considered good, with the exception of a few that have concentrations in Mn, B, Ba, As, Fe, Ni, Se, and Al, which are definitely above the estimated respective Upper Threshold Limit and, thus, exceed the corresponding legislative standard value defined by European Union directives. National regulatory bodies should verify these results, and install an efficient assessment system of compliance to regulatory limits using the methodology described in this paper.     

Water Balance and Evapotranspiration Monitoring in Geotechnical and Geoenvironmental Engineering

Among the various components of the water balance, measurement of evapotranspiration has probably been the most difficult component to quantify and measure experimentally. Some attempts for direct measurement of evapotranspiration have included the use of weighing lysimeters. However, quantification of evapotranspiration has been typically conducted using energy balance approaches or indirect water balance methods that rely on quantification of other water balance components. This paper initially presents the fundamental aspects of evapotranspiration as well as of its evaporation and transpiration components. Typical methods used for prediction of evapotranspiration based on meteorological information are also discussed. The current trend of using evapotranspirative cover systems for closure of waste containment facilities located in arid climates has brought renewed needs for quantification of evapotranspiration. Finally, case histories where direct or indirect measurements of evapotranspiration have been conducted are described and analyzed.     

剪切波速测量中地面木板敲击方法和悬挂式井中测试方法的结果比较

地面木板敲击方法和悬挂式井中测试方法是工程中常用的两种剪切波速测量方法。在长期的工作中发现,对于类似的场地,不同的方法所得到的测试结果有时存在一定的差异。为此,选择了山西地区5个场地条件不同的比较典型的地震钻孔,分别采用两种方法对同一钻孔进行测试,并对结果进行了比较和分析。结果表明,在钻孔地层为土和砂且钻孔质量较好的情况下,两种方法所测数据相差不大,一般相差在10%以内。钻孔质量较差,局部有轻微塌孔、缩径的情况时,采用悬挂式测井方法误差较大。对于含有卵石地层的钻孔以及需要测量基岩面以下的地层剪切波速的钻孔,则应采用悬挂式井中测试方法。     

土氡测量在广从断裂探测中的初步应用

在广从断裂带共布置5条氡气测量剖面,利用FD-3017RaA和CDI-2000两种氡探测仪快速测定其浓度,得到土氡含量曲线图和等值线图,并分析氡异常曲线的特征,得到如下结论:广从断裂上土壤氡具有明显的峰值异常特征,通过异常峰值位置能很好地圈定断裂或隐伏断裂的位置和断裂带的宽度;利用峰值异常的几何形态能很好地判断断层的倾...