A technique for assessment of torso kinesiology

A technique is described for monitoring and analysis of the angular displacement of the human torso. The technique is based on the use of miniature electromechanical inclinometers and video recording. The system was developed for continuous measurement of the angular displacement of spinal segments in the sagittal plane during all stages of lifting. Angular displacements of the cervical, thoracic and lumbar regions were obtained from a dynamic lifting case study using a digital processing system. The geometrical changes of the torso during five prescribed stages were measured. The system revealed good accuracy with high correlation coefficient scores for a wide range of lifting tasks in a comparative laboratory study. This paper describes the monitoring technique; the system's advantages, disadvantages and measuring accuracy are discussed.     

The minimum quantity of nitrite required to stain sliced and homogenised cooked pork

The levels of nitrite used in curing pork are in excess of those required to produce an adequate cured colour, but the minimum level for pink coloration to be visible has not been established experimentally. This paper demonstrates the effect of low nitrite levels from local surface application to pork muscle, simulating inadvertent contamination from work surfaces. An homogenate is used for comparison in which the nitrite was evenly distributed throughout the product. The results indicate that surface contact with nitrite produces essentially the same pattern of colour change as in the homogenate. Visible pink coloration was evident from 1-2 mg kg(-1) sodium nitrite absorbed.     

考虑风电消纳的电-热综合能源系统优化运行

针对北方供暖期的弃风问题,在传统电-热联合系统的基础上,建立了横向电-热互补、纵向"源-网-储"的电-热综合能源系统.系统充分考虑了供热网的热动态特性和储电、储热两种形式的储能装置,在满足电、热需求的情况下,建立以最小运行成本为目标的优化运行模型.模型在Matlab中调用YALMIP工具箱和CPLEX求解器进行求解.通过算例仿真,分析了供热网的热动态特性和储能装置对系统运行成本和弃风量的影响.并讨论了不同储能配置下,储能投资成本对系统的影响,验证了模型的合理性.     

柴油机铸铝活塞碎裂失效分析

通过对失效件整体形貌、断口、内部质量及显微组织的全面检验和试验分析 ,确定工件内部存在严重的质量问题 ,铸造冷裂纹、大型疏松孔洞和未经变质处理的缺陷组织 ,是导致构件在服役时早期失效碎裂的主要原因。     

TiO2/MOFs的制备及污染物降解现状

TiO2是较为成熟的半导体光催化材料,但因TiO2分散性差、量子利用率低、比表面积小、难回收等问题难以工业化.多孔金属有机框架(MOFs)的引入可增强TiO2/MOFs复合材料的光吸收性能,提高电子-空穴对分离效率和提高回收率.基于TiO2/MOFs制备时前驱体添加顺序不同,综述了TiO2/MOFs的3种制备方法(即Ship-in-a-bottle法、Bottle-around-ship法、One-pot法)及TiO2/MOFs光催化机理与性能影响因素,并探讨不同MOFs与TiO2结合的作用机理.最后,对TiO2/MOFs存在的问题提出建议.     

金属薄膜结合性能的评价方法研究

针对Al2O3基体上磁控溅射沉积的Au／NiCr／Ta多层金属薄膜，用压痕法、滚动接触疲劳法、摩擦力和声发射两种模式同时监测的划痕法，对比研究了金属薄膜与基体的结合性能。结果表明：压痕试验从压痕形貌上很难判断薄膜与基体是否发生剥离，压入过程中也没有诱发裂纹的产生，更无法分辨薄膜层间的分离；由于金属薄膜的塑性变形，滚动接触疲劳法很难应用于金属薄膜结合性能的表征：划痕法可应用于多层金属薄膜的特异划擦行为研究，其中摩擦力模式能反映压头进入不同金属膜层时的变化，层间声发射信号的灵敏度不如摩擦力信号，对应试验条件，摩擦力曲线存在若干以拐点为特征的载荷，摩擦力曲线上出现的拐点及拐点特征载荷值可以在一定程度上反映多层膜的层数和层厚，并可刻划出该膜／基体系承受压入载荷而不发生剥落的能力。     

热处理工艺对BT9合金疲劳和高温持久性能的影响

本文研究了不同的热处理工艺对BT9钛合金的疲劳寿命和高温持久强度的影响,并对其组织、断口进行了光学和电子金相分析。指出了获得良好的综合机械性能的热处理工艺,并讨论了在不同区域内疲劳裂纹扩展的方式。     

Effect of ultrasonic power and bonding force on the bonding strength of copper ball bonds

Copper wire, serving as a cost-saving alternative to gold wire, has been used in many high-end thermosonic ball bonding applications. In this paper, the bond shear force, bond shear strength, and the ball bond diameter are adopted to evaluate the bonding quality. It is concluded that the ef/~cient ultrasonic power is needed to soften the ball to form the copper bonds with high bonding strength. However, excessive ultrasonic power would serve as a fatigue loading to weaken the bonding. Excessive or less bonding force would cause cratering in the silicon.     

Synthesis of LaF3 superfine powder by microwave heating method

LaF3 superfine powder was synthesized from La(CH3COO)3 and NH4 F by microwave heating method,using ethanol or pure water as dispersants respectively. The results of XRD and SEM indicate that the superfine powder has high purity, regular particle shape and narrow distribution of granularity. The granularity of the best sample is in the range of 100 -200 nm. The influence of different dispersants on the crystal degree and microstructure was discussed. After the superfine powder was formed into a slice at pressure of 25 - 60 MPa, its electrochemical impedance spectroscopy was tested by electrochemical impedance spectroscopy (EIS) measurement. The result shows that the grain refining of LaF3 powder increases its ionic conductivity. Compared with traditional preparation methods of LaF3 powder, the advantages of microwave heating method were summarized.