Ultrasonic irradiation-induced degradation of low-concentration bisphenol A in aqueous solution

Lead (Pb) contamination in the black paper that recovers intraoral films (BKP) has been investigated. BKP samples were collected from the Radiology Clinics of the Dental School of Ribeirão Preto, University of São Paulo, Brazil. For sake of comparison, four different methods were used. The results revealed the presence of high lead levels, well above the maximum limit allowed by the legislation. Pb contamination levels achieved after the following treatments: paper digestion in nitric acid, microwave treatment, DIN38414-54 method and TCLP method were 997 μg g⁻¹, 189 μg g⁻¹, 20.8 μg g⁻¹, and 54.0 μg g⁻¹, respectively. Flame atomic absorption spectrometry (FAAS) and inductively coupled plasma mass spectrometry (ICP-MS) were employed for lead determination according to the protocols of the applied methods. Lead contamination in used BKP was confirmed by scanning electron microscopy coupled with energy dispersive X-ray microanalysis (SEM-EDS). All the SEM imaging was carried out in the secondary electron mode (SE) and backscattered-electron mode (QBSD) following punctual X-ray fluorescence spectra. Soil contamination derived from this product revealed the urgent need of addressing this problem. These elevated Pb levels, show that a preliminary treatment of BKP is mandatory before it is disposed into the common trash. The high lead content of this material makes its direct dumping into the environment unwise.     

消光比自动测试系统的实验研究

设计并建立了一套消光比自动测试实验系统 ,该系统实现了光、机、电、算一体化的精密测量。     

电厂动力设备状态维修管理系统的开发

状态维修是根据设备状态信息、判断设备的异常、预测设备的故障 ,在故障发生前进行维修。电厂动力设备状态维修管理系统设计思路是建立数据库 ,结合电厂现有的设备信息管理系统、物质管理系统、缺陷管理系统以及设备巡检系统等 ,建立集数据管理、分析、预测、诊断、决策于一身的设备状态维修管理系统。该系统由输入模块、输出模块、诊断预测模块、维修决策模块、数据库备份模块和索引模块等组成 。     

热处理对真空热压烧结NiCrCoTiV高熵合金组织结构及耐腐蚀性能的影响

采用真空热压烧结技术制备了NiCrCoTiV高熵合金,并分别在500℃、600℃和700℃下对高熵合金进行18h保温热处理。采用X射线衍射仪、扫描电子显微镜、电化学测试系统研究了不同热处理温度对高熵合金物相结构、微观组织及耐腐蚀性能的影响。结果表明,高熵合金的物相组成在不同温度热处理后均未发生明显改变,表现出良好的热稳定性。热处理后,高熵合金晶粒细化,析出相减少;热处理温度越高,晶粒细化效果越好。相比于未热处理的试样,热处理后试样的耐腐蚀性能明显提高,并且随热处理温度升高,耐腐蚀性能呈上升趋势。     

PcBN刀具材料在高速硬态切削中的应用研究

简要介绍了PcBN刀具材料的高压高温烧结制备方法及其物理力学性能特点、高速切削技术与硬态切削技术的特点以及PcBN刀具材料对高速硬态加工的适应性。分析和探讨了高速硬态切削对PcBN材料性能的要求,认为限制PcBN应用于高速硬态切削的主要是其高温力学性能,包括高温强度、高温硬度、高温韧性等。介绍了目前国外高速切削用PcBN材料的研究新进展,列举了PcBN刀具应用于高速硬态加工领域的实例,指出纳米级无任何粘结剂的PcBN刀具材料的开发与应用对推动我国的高速切削加工技术具有十分重要的意义。     

水煤浆的流变特性

水煤浆是固液两相的非牛顿流体．其流变性十分复杂,影响因素也较多,对水煤浆输送和燃烧起决定性作用．考察了用大同煤制备的质量分数约为７０％的煤浆的质量分数、添加剂类型、用量对煤浆流变性的影响,并分析了流变性变化的原因．     

寒冷地区楼梯间节能改造技术探讨

本文通过对楼梯间两种不同节能技术措施的比较,从技术和经济的角度,阐述在寒冷地区实施楼梯间设外保温门的节能技术措施,技术更可行,经济更合理。     

Adaptive Trajectory Tracking of Wheeled Mobile Robots Based on a Fish-eye Camera

International Journal of Control, Automation and Systems - This paper presents a novel adaptive trajectory tracking control method, which can precisely control wheeled mobile robots only using an...     

Practical Robotic Auditory Perception and Approaching Methods Based on Small-sized Microphone Array

International Journal of Control, Automation and Systems - Robot control based on audition plays an important role in many robot applications, which is generally implemented by three steps: aural...     

基于混合粒子群优化算法的火箭弹内弹道优化设计

针对无控火箭弹的内弹道优化问题,以增加射程为目标,在发动机总冲恒定的约束条件下,分别建立了固体火箭发动机单室单推模式和单室双推模式的内弹道数学模型和优化模型,采用改进的混合粒子群优化算法,对固体火箭发动机的内弹道特性进行优化设计,求得了全局最优解。仿真结果表明,提出的混合粒子群优化算法具有较好的全局寻优能力和鲁棒性,是解决固体火箭发动机内弹道优化问题的有效方法; 设计的优化策略将某型122 mm无控火箭弹的最远射程提高了3.75%～4.45%,仿真结果对无控火箭弹的总体设计具有一定的理论指导意义。