GPS授时地震仪走时误差校正

受制造成本和工艺的限制,GPS授时地震仪中的守时晶振不可避免地会有频率误差,继而在数据采集过程中,随着采集时间的增加,各台站之间会出现采集不同步现象。介绍了Akima分段多项式插值重采样方法及其在GPS授时地震仪时间校正中的应用。通过对理论数据与实际数据的Akima插值重采样试验表明,Akima插值重采样方法可应用于GPS授时地震仪走时误差校正,是一种简便、高效、保形性好的插值重采样方法。     

Occupational hazards in printing industry

This paper, through certain printing techniques, examines the types of occupational pollutants and the adverse impacts of the printing process. Also, it proposes the measures for better preservation and environmental protection. The paper analyzes the results of the quantitative identification of hazardous materials from various printing techniques: pad, screen, offset, flexographic, and digital. The study included the analysis of waste printing inks and purification of printing wastewater with adsorption methods. Besides that, the preliminary monitoring of ambient indoor air quality was performed. The multiple regression analysis was applied on the obtained experimental results, in order to determine the mutual correlation between the ozone and the total volatile organic compounds and microclimate parameters. It was observed that a quantitative correlation exists between the investigated occupational hazards, which also indicate the strength of the agreement. The obtained results could be useful to evaluate the tendency of hazardous air pollutants in printing industries worldwide.     

Measurement error in compositional data

Compositional data, consisting of vectors of proportions summing to unity such as the geochemical compositions of rocks, have proved difficult to analyze. Recently, the introduction of logistic and logratio transformations between the d-dimensional simplex and Euclidean space has allowed the use of familiar multivariate methods. The problem of how to model and analyze measurement errors in such data is approached through the concept of a perturbation of a composition. Such modeling allows investigation of the role of rescaling, quantification of measurement error, analysis of observor error, and assessment of the effect of measurement error on inferences.     

Random error in point counting

In point counting, the selection of a random subset from the counting grid permits random errors to be described by a simple mixed binomial model. The model is independent of any grain size considerations, and general formulas are presented giving upper bounds to the number of sections required.     

3D打印技术在岩石物理力学试验中的应用

3D打印技术在岩土工程领域的应用还处于初步探索阶段,但其可重复制造含复杂内部结构的试样是常规室内试验无法实现的。现阶段制约3D打印技术在岩石物理力学试验中应用的主要因素在于3D打印试样强度偏低,延性较强。初步探讨了3D打印后干燥时间、打印胶水浓度对试样强度的影响,在此基础上提出了最优化打印方案,使打印试样在强度和脆性方面均有很大提升;通过改变打印方向模拟了天然层状节理岩石的各向异性特征。研究结果表明,随着打印倾斜角度的增加,3D打印试样的单轴抗压强度先减小后增大,呈"U"型变化趋势,抗拉强度也随打印方向的改变出现明显的各向异性特征,这与天然层状节理岩石相关研究成果相似。研究成果可为3D打印技术在岩土工程领域的推广和室内试验研究提供参考。     

GPS测量误差分析

GPS测量以其显著的定位特点,得到了空前的应用和发展。它取代了常规的大地测量和工程控制测量,现在已渗入到工程测量、地籍测量、交通管理、导航、地理信息系统、海洋、石油、气象和地球科学等许多研究领域。同时GPS还涉及数学、天文学、数字通讯、计算机科学、测绘学等多学科领域。GPS测量应用的广泛开展,使观测精度的影响因素和解决方法成为科学研究工作中的重点。由于GPS测量涉及多学科、多应用领域,给研究的方向、方法提出了更高的要求。本文介绍了影响GPS测量精度的因素和常用的解决方法。     

地质图件绘制与数字化制图印刷

地质图件专业性强，种类多，色层多。根据其特性一般可分为基础地质图（地质图、岩性古地理图、勘探部署图等）、经济地质图（勘探成果图、地质矿产图、水文地质图等）、以及勘探工程图、钻井综合柱状图、钻井地层对比图等。1 地质图件绘制 绘制地质图件程序为：绘制内图廓线→绘制测量控制点→绘制居民、地质工程符号→绘制水系、道路；绘制地质界线、断层→绘制等值(深)线等→绘制外图廓线图外整饰；审校。由于地质图件种类多、要素多，可采取分版绘制。分版绘制目的主要是为了减少印刷时复杂的分涂工作。但分版的版数应掌握适当，可把…     

Correction and protection in limestone terrane

Structural features that are hazards to building foundations include pinnacles, slots, and chimney-like openings in rock, alternate strata of hard rock and soft clay, dome-like cavities in soil, caves in rock, weak and compressible soils in cone-shaped depressions over collapsed domes and cavities, and open sinkholes from soil or rock collapse and soil erosion Design to overcome them includes avoiding areas of concentrated hazards, correcting the hazards by filling them or collapsing them, bridging over small hazards, reinforcing the rock, bypassing shallow hazards with deeper foundations, and minimizing activation of the hazard-forming processes.     

GPS在测量中的应用及误差分析

简述了全球定位系统（GPS）的基本结构和特点,总结了GPS用于工程测量所具有的特点,介绍了GPS在工程测量中的应用实例及体会。简述了GPS系统的定位误差直接影响着GPS定位精度,按其产生的来源、性质及对系统的影响等进行了介绍和初步分析,提出了相应的措施以便消除或削弱它们对测量结果的影响。     

浅谈影响GPS测量的误差因素及分析

本文简述的GPS在测量中产生的误差源,并进行了分析及提出消除和削弱对测量影响的措施。