非饱和砂土抗拉强度的试验研究

含水合物土的抗拉强度特性对含水合物地层的稳定评估具有重要意义。以黏质粉土为赋存介质,利用四氢呋喃(THF)合成含水合物土试样,在冷冻库中利用改进后的单轴拉伸装置研究了含水合物土单轴抗拉强度特性。试验结果表明水合物饱和度、试样干密度、细粒含量对含水合物土的抗拉强度存在明显影响。随着水合物饱和度的增加,抗拉强度呈现指数函数的增长趋势。干密度和细粒含量对抗拉强度的影响在不同的水合物饱和度情况下影响不同,在低水合物饱和度情况下,干密度和细粒含量的增加会使抗拉强度增强;而在较高的水合物饱和度情况下,抗拉强度则随着干密度和细粒含量增加而降低。此外,通过分析含水合物土的波速特性,建立抗拉强度与波速之间的经验关系式。这一关系式对采用声波来估算含水合物土试样的抗拉特性具有重要的参考意义。     

论氢化物的形成及其在分析测试领域的应用

论述了氢化物形成的普遍性、氢化物的物理化学性质、元素周期系各类元素的氢化物类型。认为一些金属离子、非金属离子在酸性介质中与硼氢化钾（钠）作用及金属锌等强还原剂作用生成氢化物。综述了氢化物的形成在分析测试领域的应用：试样分解、分离富集、容量分析、光度分析、原子光谱分析、质谱分析。     

Seismic microzonation studies for the city of Ragusa (Italy)

The seismic history of the city of Ragusa (Italy), the geotechnical characterisation of the subsoil and the site response analysis should be correctly evaluated for the definition of the Seismic Geotechnical Hazard of the city of Ragusa, through geo-settled seismic microzoning maps. Basing on the seismic history of the city of Ragusa, the following earthquake scenarios have been considered: the “Val di Noto” earthquake of January 11, 1693 (with intensity X–XI on MCS scale, magnitude M_W=7.41 and epicentral distance of about 53 km); the “Etna” earthquake of February 20, 1818 (with intensity IX on MCS scale, magnitude M_W=6.23 and epicentral distance of about 64 km); the Vizzini earthquake of April 13, 1895 (with intensity I=VII–VIII on MCS scale, magnitude M_W=5.86 and epicentral distance of about 26 km); the “Modica” earthquake of January 23, 1980 (with intensity I=V–VI on MCS scale, magnitude M_W=4.58 and epicentral distance of about 10 km); the “Sicilian” earthquake of December 13, 1990 (with intensity I=VII on MCS scale, magnitude M_W=5.64 and epicentral distance of about 50 km). Geotechnical characterisation has been performed by in situ and laboratory tests, with the definition of shear wave velocity profiles in the upper 30 m of soil. Soil response analyses have been evaluated for about 120 borings location by some non-linear 1-D models. Finally the seismic microzonation of the city of Ragusa has been obtained in terms of maps with different peak ground acceleration at the surface; shaking maps for the central area of the city of Ragusa were generated via GIS for the earthquake scenarios.     

Large-scale dune erosion tests to study the influence of wave periods

Large-scale physical model tests were performed to quantify the effects of the wave period on dune erosion. Attention was focussed on 2D cross-shore effects in a situation with sandy dunes and extreme water levels and wave conditions. Besides profile measurements, detailed measurements in time and space of water pressure, flow velocities and sediment concentrations were performed in the near near-shore area. It was concluded that a longer wave period leads to a larger dune erosion volume and to a larger landward retreat of the dune face. Tests with double-peaked wave spectra showed that the influence of the spectral shape on dune erosion was best represented by the T_m − 1,0 spectral mean wave period, better than the peak wave period, T_p. The effect of the wave period on dune erosion was implemented in a dune erosion prediction method that estimates erosion volumes during normative storm conditions for the Dutch coast. More details of the measurements and additional analyses of physical processes are described in an accompanying paper by Van Thiel de Vries et al. [Van Thiel de Vries, J.S.M., van Gent, M.R.A., Reniers, A.J.H.M. and Walstra, D.J.R., submitted for publication. Analysis of dune erosion processes in large scale flume experiments, In this volume of Coastal Engineering.].     

Wave tank and bench-top control testing of a wave energy converter

An increasing number of experiments are being conducted to study the design and performance of wave energy converters. Often in these tests, a real-time realization of prospective control algorithms is applied in order to assess and optimize energy absorption as well as other factors. This paper details the design and execution of an experiment for evaluating the capability of a model-scale WEC to execute basic control algorithms. Model-scale hardware, system, and experimental design are considered, with a focus on providing an experimental setup capable of meeting the dynamic requirements of a control system. To more efficiently execute such tests, a dry bench testing method is proposed and utilized to allow for controller tuning and to give an initial assessment of controller performance; this is followed by wave tank testing. The trends from the dry bench test and wave tank test results show good agreement with theory and confirm the ability of a relatively simple feedback controller to substantially improve energy absorption. Additionally, the dry bench testing approach is shown to be an effective and efficient means of designing and testing both controllers and actuator systems for wave energy converters.     

JGN型耐高温建筑结构胶抗震加固性能研究

为有效增强建筑结构的抗震性能、提高建筑抗震水平,对JGN型耐高温建筑结构胶抗震加固性能展开研究。将高活性酚醛胺(T－31)作为主固化剂、聚酰胺树脂(PA)为辅助固化剂,结合气相白炭黑、超细石英砂、石棉纤维、纳米材料、环氧树脂等材料,制备JGN型耐高温建筑结构胶。在高温环境下,使用万能试验机分析不同配比条件对结构胶抗震加固性能的影响。测试主要以拉伸强度、压缩强度以及压缩弹性模量为指标。测试结果表明：当固化剂质量比为45∶15、气相白炭黑掺量为4.5%、超细石英砂掺量为10%、石棉纤维掺量为10.5%、纳米SiO₂掺量为3.5%、纳米CaCO₃掺量为2.5%时,JGN型耐高温建筑结构胶的拉伸强度和压缩强度更大,压缩弹性模量得到优化,结构胶的抗震加固性能达到最佳状态。     

Sample Disturbance in Soft and Sensitive Clays: Analysis and Assessment

Despite the sophisticated methods employed to obtain high quality samples, they are prone to disturbance, due to stress release, let apart, due to sampling tools and techniques adopted. Critical reappraisal of different methods suggest that any method of sample quality assessment involving strength and deformation parameters would enable easier implementation and correct other engineering parameters for estimated sample disturbance. In this technical paper, sample disturbance index, using merely the slopes of compression paths, (representing mechanical response), in the pre- and post-yield stress regimes under odeometric loading conditions is proposed. This method is based on single oedometer test results on samples of unknown degrees of disturbance during sampling and handling. The unique feature of this approach is that the ideal rigid plastic material behavior is taken as reference. This eliminates the need for any additional experimental data or any calculations from the relationships formulated with any set of assumptions.     

转矩转速传感器及其在钻机功率测试中的应用

介绍了一种用于钻机功率测试的转矩转速传感器，论述了该类传感器的基本工作原理、标定装置、校验方法以及测试系统的组成等问题。     

Statistical diagnosis and gross error test for semiparametric linear model

This paper systematically studies the statistical diagnosis and hypothesis testing for the semiparametric linear regression model according to the theories and methods of the statistical diagnosis and hypothesis testing for parametric regression model. Several diagnostic measures and the methods for gross error testing are derived. Especially, the global and local influence analysis of the gross error on the parameter X and the nonparameter s are discussed in detail; at the same time, the paper proves that the data point deletion model is equivalent to the mean shift model for the semiparametric regression model. Finally, with one simulative computing example, some helpful conclusions are drawn.