Quality ranking of twelve columnar basalt occurrences in the northern portion of the Paraná Basin—Brazil

This paper presents results obtained from a study of basal degrading conducted on samples of basaltic rocks found in the northern part of the Paraná Basin in the State of São Paulo, Brazil. To meet the objectives of the study, natural and accelerated alteration tests were carried out followed by a comparison of the quantitative analysis of the two alteration processes. The combined analysis of the information proved to be very useful tool for rock qualification and the quantification of alterability, thus providing a basis for comparative analysis of massive and columnar jointed basalt relative to their use as aggregate for civil construction purposes.     

火焰原子吸收光谱法测定银锡焊料中的微量铅

利用四价锡的氯化物沸点较低的性质,将锡挥发除去,并用硫脲络合银离子,以消除银和锡对铅测定的干扰。制定了火焰原子吸收光谱法测定银锡焊料样品中微量铅的分析方法。方法准确、可靠、简便、快速,完全适用于银锡焊料中微量铅的检验。     

What Kind of Assessment for What Kind of Geography? Advanced Placement Human Geography*

This article raises awareness of the recently introduced Advanced Placement course in Human Geography by describing the design and management of assessment in the course. Standards are maintained through the choice of assessment instrument, the development of test items, scoring, and grade‐setting. The article contributes to a deeper understanding of the opportunities and threats of standardized testing within geography.     

Operator‐splitting method for real‐time substructure testing

It has been shown that the operator‐splitting method (OSM) provides explicit and unconditionally stable solutions for quasi‐static pseudo‐dynamic substructure testing. However, the OSM provides only an explicit target displacement but not an explicit target velocity, so that it is essentially an implicit method for real‐time substructure testing (RST) when the velocity‐dependent restoring force is considered. This paper proposes a target velocity formulation based on the forward difference of the predicted displacements so as to render the OSM explicit for RST. The stability and accuracy of the resulting OSM‐RST algorithm are investigated. It is shown that the OSM‐RST is unconditionally stable so long as the non‐linear stiffness and damping are of the softening type (i.e. the tangent stiffness and damping never exceed the initial values). The stability of the OSM‐RST for structures with infinite tangent damping coefficient or stiffness is also proved, and the stability of the method for MDOF structures with a non‐classical damping matrix is demonstrated by an energy criterion. The effects of actuator delay and compensation are analysed based on the bilinear approximation of the actuator step response. Experiments on damped SDOF and MDOF structures verify that the stability of the OSM‐RST is preserved when the experimental substructure generates velocity‐dependent reaction forces, whereas the stability of real‐time substructure tests based on the central difference method is worsened by the damping of the specimen. Copyright © 2005 John Wiley & Sons, Ltd.     

山前洪积扇地基岩土勘察和测试工作——以郑州发祥铝业建设工程为例

简述了洪积扇地形地貌、土层结构、水文地质、特殊性岩土等各种工程地质条件，划分了勘察阶段，明确了各阶段勘察目的和任务，并重点介绍了在详细勘察阶段优质、高效完成野外勘察和测试工作的成功经验，明确指出了洪积扇场地非常适合钻孔、探井、测井等勘察手段和动力触探等原位测试方法。     

软件工程中并发测试的研究与实践

随着计算机技术和Internet的发展，相对于以前的单机版的应用软件，目前已有众多的网络版应用软件犹如雨后春笋，不断的涌现出来，这对传统的测试方法和理论提出了新的挑战。这里重点介绍了基于Internet网络版应用程序的并发测试方法研究与技巧，提供了一些实践经验，总结了在并发测试时应该注意的一些实际问题。     

鄂西高速公路岩体结构面强度参数试验研究

对湖北省西部某高速公路宜昌—恩施段主要岩体结构面(层面)的抗剪强度参数进行了较系统的试验研究,包括岩体结构面的野外地质调查、岩体结构面原位直剪试验、结构面室内模拟试验及岩体力学参数估值等。通过对各种试验数据进行整理、分析和对比,得到了岩体结构面强度参数。最后在岩体工程分类的基础上,利用Hoek-Brown经验方法对各类岩体结构面强度参数进行了估算。综合以上多种数据,并考虑岩体结构面所处具体地质条件,提出了各类岩体结构面强度参数建议值。     

Investigations into the Preparation of Ultra-Fine Particle Size Geochemical Reference Materials

Although over recent years, sensitivity and precision of modern analytical techniques have continuously improved, traditional analytical specification for the particle size of samples has remained at 74 μm (-200 mesh). For this reason, the uncertainty caused by inhomogeneity in test portions of the sample itself has become a more and more significant contribution to the total analytical uncertainty. Therefore, to reduce this total uncertainty, the first step is to improve the homogeneity by reducing the particle size of a sample. For this purpose, we have investigated a method for the preparation of ultra-fine reference materials. Using the modern ultra-fine crushing technique (jet mill), six marine sediment samples MSAn and MSCS-1 to 5 were prepared and the particle distributions of these samples were measured using a laser particle-analyser. The average particle size of these samples was 4–5 (im and the largest particle size was less than 30 (im. MSAn will be used as the sample for a future GeoPT(tm) proficiency testing round and MSCS-1 to 5 will be prepared as reference materials. All geochemical laboratories are welcome to participate in this co-operative research programme. The processing and use of ultra-fine samples (< 30 μm) will have a significant influence on the future development of geoanalytical techniques as a consequence of the potential reduction in the mass of test portion and the development of new geoanalytical systems.     

GA型旁压仪的应用及成果分析

在南水北调工程中应用ＧＡ型旁压仪对地基进行原位测试。介绍了ＧＡ型旁压仪的基本结构、工作原理、测试及有关计算方法,并对其典型旁压的试验成果进行了分析。     

微机数控旋转流变仪的设计

微机数控旋转流变仪是一种泥浆流变参数微机智能检测仪器。介绍了其工作原理、性能指标和特点,以及硬件、传感器设计和软件功能设计。