递增负荷运动过程中股四头肌表面肌电图的变化

表面肌电信号的检测是一种无创电检测方法,它的检测分析对临床诊断及康复医学,运动医学等具有重要意义。肌肉疲劳产生过程中,肌电图的振幅和频谱指标均会产生相应变化,肌肉疲劳通常是指肌肉运动系统最大做功能力或最大收缩能力暂时下降。SEMG信号可以在一定程度上反映肌肉收缩功能的变化,在运动性肌肉疲劳研究中将发挥重要作用。     

Microclimate inside a semi-confined environment: Valuation of suitability for the conservation of heritage materials

The microclimatic analysis of the Petrarca's tomb in Arquà Petrarca, Padua (Italy) was performed to assess the suitability of a closed environment located outdoors respect to the conservation requirements of heritage materials. Results showed that the thermo-hygrometric conditions inside the tomb were not suitable for the conservation of organic materials, like bones and wood. The orientation (north or south) was the main responsible for the different damage features of the two sides of the wooden case housing the human remains inside the tomb. Technical solutions were finally implemented to improve the conservation conditions, thus avoiding further damage.     

复杂地表与地质地震资料处理技术研究与应用综述

复杂地区典型特征往往表现为近地表地质结构复杂,纵向、横向变化大,地下地质构造破碎,大倾角老地层出露。介绍了该类地区地震资料的主要特点;分析了处理好该类地震资料起决定性作用的静校正、去噪技术、频率补偿及偏移成像几个重要环节,并指出了生产中应注意的几个问题。     

纳米金胶体对吖啶橙水溶液的荧光增强效应

以纳米金胶体颗粒为增强衬底,观测了两种不同浓度的吖啶橙水溶液荧光信号的表面增强效应,并用激发光波长与金胶表面等离子体共振的匹配理论,以及近场增强理论解释了所观测到的现象.     

双三次贝齐尔曲面的特性与应用

计算机图形学是计算机科学中最主要的分支之一，其核心技术是如何建立所处理对象的模型并生成该对象的图形。本文阐述计算机图形学中的拟合原理，双三次贝齐尔曲面的特性，介绍与该曲面有关的程序代码以及程序的运行结果。     

几何画板轨迹功能在三维曲面绘制中的应用

探讨了几何画板的绘图功能在空间曲面绘制中的应用,给出通过建立基础网格利用“轨迹”功能绘制曲面网状图和建立三维坐标系利用“追踪”功能绘制曲面的方法。     

Surface settlement caused by twin-parallel shield tunnelling in sandy cobble strata

City metro tunnels are usually constructed as twin-parallel tunnels and their adjacent construction may lead to surface deformation, affecting the surface environment and the safety of the tunnels. Due to its strong dispersion, sandy cobble strata can be easily disturbed by shield tunneling. Based on the project of the Chengdu Metro Line 1, field and model tests were carried out to study the surface settlement caused by shield tunneling in sandy cobble strata by measuring surface settlement curves, ground loss ratios and construction influence zones. The discrete element method (DEM) was used to study the factors affecting the formation of ground arches in sandy cobble strata at the microscopic level. Results show that the shape of the surface settlement curve in sandy cobble strata is different from that in soft soil. The buried depth and clear spacing of the two tunnels had a significant impact on the formation of ground arches.     

Study on the thermal decomposition kinetics of nano-sized calcium carbonate

This study of the thermal decomposition kinetics of various average diameter nano-particles of calcium carbonate by means of TG-DTA (thermogravimetry and differential thermal analysis) showed that the thermal decomposition kinetic mechanisms of the same crystal type of calcium carbonate samples do not vary with decreasing of their average diameters; their pseudo-active energyE _a; and that the top-temperature of decompositionT _p decreases gently in the scope of micron-sized diameter, but decreases sharply when the average diameter decreases from micron region to nanometer region. The extraordinary properties of nano-particles were explored by comparing the varying regularity of the mechanisms and kinetic parameters of the solid-phase reactions as well as their structural characterization with the variation of average diameters of particles. These show that the aggregation, surface effect as well as internal aberrance and stress of the nano-particles are the main reason causing bothE _a andT _p to decline sharply with the decrease of the average diameter of nano-particles. Project supported by Guizhou Province Natural Science Foundation of China     

A comparative study of student attitude,learning and teaching practices in Pakistan and Britain

Good teaching is open to change and it involves constantly trying to find out what the effects of instruction are on learning, and modifying that instruction in the light of the evidence. Similarly, the ultimate outcome of instructional practice is effective student learning. Therefore, in this perspective, adequately meeting the varying needs of students is a major challenge for the modern education system in every country. As the title indicates, this paper attempts to explore students’ attitudes to studying and learning in order to help encourage greater engagement with quality learning. The study is based on primary data with regard to postgraduate education and learning in respective British and Pakistani education institutions—i.e. Moray House School of Education (Edinburgh University) and the Institute of Education and Research (University of the Punjab, Lahore). In the context of the collaboration of these two institutions, the paper focuses on the ways and means to enhance the system‐wide capacity for research‐based practice.     

Modeling of contact surface morphology and dust particles by using finite element method

The effect of dust particles on electric contacts and a hazardous size range of hard dust particles using a rigid model were discussed before. As further research, elastic-plastic model of finite element analysis was established in this work, which is closer to real condition. In this work, the behavior of large size and small size particles, and the influence of particles hardness were investigated. The calculating result of small-size particles presents a general hazardous size coefficient for different contact surface morphology; for large-size particles, it presents a hazardous size coefficient for complicated composition of the dust. And the effect of the dust shape is also discussed.