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11.
The problem of drained cavity expansion in soils of finite radial extent is investigated. Cylindrical and spherical cavities expanded from zero radius subjected to either constant stress or zero displacement at the finite boundary are considered. The generalised analytical solution procedure presented enables more advanced constitutive models to be implemented than have been possible in previous studies. Results generated for Sydney quartz sand highlight substantial differences between cavity limit pressures for the two boundary conditions and for boundaries of finite and infinite radial extent. This is of significance in accounting for boundary effects when interpreting cone penetration tests conducted in calibration chambers. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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13.
YONGDONG WANG ODD S.BORGEN BRUCE R.KOWALSKI Laboratory for Chemometrics Center for Process Analytical Chemistry Department of Chemistry BG- University of Washington Seattle WA U.S.A. Present address:Perkin-Elmer Corporation Main Avenue Norwalk CT - U.S.A. 《地理学报(英文版)》1993,(5)
Through theoretical analysis and computer simulation,this short communication comments on theresidual bilinearization(RBL)method and compares it with non-bilinear rank annihilation(NBRA)forthe treatment of second-order calibration with non-bilinear data.It is found that these two methods aremathematically equivalent but have different noise propagation properties.The second-order advantage,namely quantitation in the presence of unknown interferences,can be carried over to non-bilinear dataonly if there exists a net analyte rank(NAR)for the analyte of interest. 相似文献
14.
从微震仪标定的基本公式出发,以误差理论为基础,以DD—1型地震仪为例,导出标定中各因素对标定精度的影响;并用概率统计方法,对标定精度做了比较符合实际的计算,进而提出了提高标定精度的改进措施。 相似文献
15.
本文对如何利用强震加速度记录测定近震震级ML的问题进行了研究,指出了在我国所使用的原始量规函数存在着系统偏差,并用回归现有观测资料的方法修正了这种系统偏差。用修正后的量规函数,利用近场加速度记录计算的ML值同微震台网所测定的值符合得较好,说明本文所提出的方法是可行的。 相似文献
16.
Vilmos Vasvri 《Atmospheric Research》2005,77(1-4):18
The Institute of Urban Water Management and Landscape Water Engineering of the Graz University of Technology (Austria) operates a hydrological research area in the City of Graz. In this urban research area precipitation and runoff data are collected by order of the municipality of Graz. At present precipitation data are measured by seven tipping bucket rain gauges. Comparative measurements have shown a deviation between the recorded and the actual precipitation intensity. This made the institute calibrate the rain gauges periodically. In the middle of the 1990s, the development of a field calibration kit was started. Based on the experiences with the first field calibration kit, a microprocessor controlled device was developed. With this calibration device, the tipping bucket rain gauges are calibrated at regular intervals. In this paper the calibration process and the current results for seven rain gauges are discussed. The calibration process is dynamic calibration and uses a peristaltic pump. Not all of the tipping buckets investigated underestimate the rain intensity in the whole measuring range. Several rain gauges have a positive relative deviation, not exceeding 22%, in the low intensity range up to 0.5 mm/min. Positive deviation can be explained by retention of water in the buckets between tips. The reason for the negative deviation is the loss of water during the tips. It leads to the underestimate of the actual intensity. The largest relative deviation in the range of underestimate exceeds 30%. In the range of extreme intensities, the larger buckets (5 cm3) show a lower relative deviation than the smaller (2 cm3) buckets. The gauge characteristic can change in favourable or unfavourable directions after several years. Therefore, the calibration of tipping buckets is recommended at least every 2 to 3 years. 相似文献
17.
Lin Xiankan 《中国地震研究》2007,21(2):139-146
The author carefully selected earthquakes with M_L=4.0~5.0, 215 occurring in the crust in the Taiwan region. The attenuation characteristics of maximum displacement recorded by the Fujian digital network have been obtained by multi-analysis as follows:logA=2.07 231.1/Δ (150km≤Δ≤650km) And the corresponding expression of calibration function is, R(Δ)=3.45-231.1(1/Δ-0.01) (150km≤Δ≤650km) Then, the author determined the magnitude and its error with the data from the Fujian network using the calibration function brought forward in 1997 and the above formula for 790 earthquakes occurring in the crust in the Taiwan region from September 1997 ~ August 2005. The result indicates that the average error of the network is 0.20 with the former and 0.18 with the latter. The average error is 0.13 with the latter with station correction. Compared with the magnitude determined by Taiwan seismologists, the magnitude value with the former is lower by 0.50 on average and that with the latter is higher by 0.08 on average. 相似文献
18.
Coastal erosion is an immense economic and social problem that has been receiving increased attention in recent years. A number of devices have been developed to determine the sediment stability in coastal areas: laboratory and field flumes; a range of different erosion devices; shear vanes and fall cone penetrometers. The cohesive strength meter (CSM) erosion device was developed to determine in situ the temporal and spatial variations in the erosion threshold of muddy intertidal sediments. Technological developments have enabled considerable improvements to be made to the original design over the last 15 years. 相似文献
19.
A model for adjustment of differential gravity measurements with simultaneous gravimeter calibration
A mathematical model is proposed for adjustment of differential or relative gravity measurements, involving simultaneously
instrumental readings, coefficients of the calibration function, and gravity values of selected base stations. Tests were
performed with LaCoste and Romberg model G gravimeter measurements for a set of base stations located along a north–south
line with 1750 mGal gravity range. This line was linked to nine control stations, where absolute gravity values had been determined
by the free-fall method, with an accuracy better than 10 μGal. The model shows good consistence and stability. Results show
the possibility of improving the calibration functions of gravimeters, as well as a better estimation of the gravity values,
due to the flexibility admitted to the values of the calibration coefficients.
Received: 15 November 1999 / Accepted: 31 October 2000 相似文献
20.
根据《全国天气雷达终端更新》和《全国天气雷达定标》项目的技术规定,研制了一套完整的雷达业务数据处理系统,实现了全国布网天气雷达数据格式统一、产品生成、产品分发和图像回显的全自动化业务,提高了我国天气雷达网的业务质量、以及数据处理和产品应用水平,收效显著。在研发过程中,充分考虑了业务条件、实际要求和探测技术的发展,系统功能丰富,算法先进,接口开放,设计精美,投入业务两年来系统运行稳定。该系统放弃了传统对话框和工具栏的设计方式,创新设计了操作面板控制。文中的研发思路,设计方法,系统特点对我国业务软件的研制具有很好的借鉴作用。 相似文献