Tool wear of coated drills in drilling CFRP

This study aimed to investigate the wear of certain coated drills when drilling carbon fiber reinforced composites (CFRP). Three different drills were used in the drilling experiments: uncoated, diamond coated and AlTiN coated carbide (WC–Co) drills. The tool wear in CFRP machining was quite different from that in conventional metal machining. The primary wear type was a dulling or blunting of the cutting edge, which has been referred to as edge rounding wear or edge recession. In this paper, a hypothesis has been developed to explain the edge rounding wear in CFRP machining. Due to the fracture-based chip formation of CFRP, there is lack of the work material stagnation zone in front of the cutting edge, which normally prevents the edge wear in metal machining. Series of wear lead to rapid dulling of the cutting edge. The resistance to edge rounding wear on the coated as well as uncoated drills has been investigated. The diamond coating significantly reduces the edge rounding wear. However, AlTiN coated drills showed no visible improvement over the uncoated carbide drill, despite of their high hardness, thus not protecting the drill. The wear mechanisms of the uncoated carbide drill and coatings are discussed. It is believed that the 2-body and 3-body abrasive wear fail to explain the observed tool wear in CFRP drilling. However, the wear of the coatings and uncoated carbide substrate from tribo-meter tests correlated well with the tool wear in the CFRP drilling. Therefore, the tribo-meter test can be used to screen the prospective tool materials before carrying drilling experiment.     

Insertable thin film thermocouples for in situ transient temperature monitoring in ultrasonic metal welding of battery tabs

Real-time monitoring and control of temperature in ultrasonic joining of battery tabs and coupons are important for the quality improvement and cost reduction of battery assembly. However, there have always been difficulties in accurate and real-time measurement of temperature by conventional sensors for practical implementation. In this study, an innovative method is developed to provide an enabling technology for the in situ transient temperature monitoring, which could provide reliable feedback signals for potential control of ultrasonic joining processes. Micro thin film thermocouples (TFTCs) were fabricated on thin silicon substrates, which were then inserted in the welding anvil as a permanent feature so that the sensors were always located about 100 μm directly under the welding spot during joining of multilayer Ni-coated Cu thin sheets for battery assembly. Good repeatability was demonstrated while a temperature rise of up to 650 °C was obtained due to the closeness of the sensors to the welding spot. The inserts with thin film sensors remained functional after welding experiments. This method has a great potential for in situ transient temperature monitoring, and thus the control of ultrasonic joining processes to realize a practical smart joining system.     

河南油田安全典型问题、险肇事件、事故原因分析及对策

系统分析了中国石化河南油田分公司近年来安全典型问题、险肇事件、事故的分布及产生原因,提出了针对性的应对措施。     

采用双螺杆泵安全输送液硫技术

分析了液硫输送液下泵的结构、运行状况及存在的安全问题,提出应用双螺杆泵输送液硫,使用证明双螺杆泵具有故障率低、检修费低、本质安全等优点。     

某采油厂新建产能建设项目(地面工程)职业病危害预评价

对某采油厂新建产能建设项目(地面工程)可能产生的职业病危害因素进行了识别与预评价,从职业病防治角度评估了建设项目的可行性,提出了必要的职业病危害防护对策和建议。     

复合微生物菌剂在近海污水中的修复作用研究

采用直接投加复合微生物菌剂原位修复深圳湾污染水体,去除水体中的有机物、氮和磷等污染物,15天检测分析微生物处理对水体溶解氧（DO）、氨态氮（NH4-N）、悬浮物（SS）、总氮（TN）、总磷（TP）变化的影响。结果表明：采用微生物技术修复深圳湾近海污染水环境具有显著效果,试验期间水体中DO明显提高,最佳复配硝化茵（B2）与枯草芽孢杆菌（B6）对NH4-N降低了53．9％,悬浮物（ss）降低了56．9％,总氮（TN）降低52．1％,总磷（TP）降低57．6％。有害弧菌单一菌落数降低了64．9％     

人工湿地堵塞机理及防堵措施浅析及研究

人工湿地作为一种高效率、低投资、低运行费用、低能耗的污水处理技术,越来越受到世界各国的关注。随着人工湿地的不断推广与应用,堵塞是影响其应用和推广的主要因素之一。湿地发生堵塞后,基质的渗透系数会急剧下降,过水能力也随之降低,大量引入湿地系统的污水直接雍积在湿地表面,长期积水引发恶臭、导致蚊蝇滋生,恶化运行环境。本文通过对人工湿地运行过程中出现的填料堵塞机理与特点进行分析,归纳和总结了人工湿地堵塞的影响因素,提出了人工湿地堵塞相应的解决措施,提高人工湿地对污水的处理效果,以期能够为人工湿地的应用及推广提供参考。     

溪源宫水源保护区浮游植物群落结构分析研究

文章主要对2011年8月至12月溪源宫水源保护区浮游植物群落结构进行调查分析。溪源宫水体共鉴定出浮游植物6门51属137种,主要都是以绿藻门、硅藻门、蓝藻门为主。通过采用浮游植物生物量以及多样性指数对研究区域水体进行了评价,结果表明溪源宫水源保护区水质状况较好。同时还将溪源宫水源保护区、闽江、山仔水库等不同水源地的浮游植物群落结构进行对比分析,发现不同营养状态下,水体中浮游植物群落结构有显著的不同。     

飓风“桑迪＂的影响及启示研究

城市地区突发自然灾害常常会对给水排水设施造成不利影响。飓风“桑迪”于2012年10月29日登陆美国,多个东部城市出现大面积停电,缺水,交通中断以及罕见的城市内涝,造成重大人员伤亡和巨额财产损失,严重地影响了当地人们正常的生产和生活。从飓风“桑迪”对美国城市给水和排水系统造成的巨大破坏出发,并结合当地政府采取的紧急应对措施展开讨论,总结其中的经验教训及启示。     

苏皖交界北西向断裂构造地震危险性分析

苏皖交界近年来不断有地震发生,2012年7月发生了Ms4.9级地震,造成了一定的破坏,其社会影响大。在此震情形势下,本文通过分析苏皖交界北西向断裂构造的活动特征、北西向断裂构造与历史破坏性地震及现代2.0级以上地震间的关系,认为苏皖交界区域沿扬州—六合—高邮—盱眙—洪泽—带被北西向的自来桥—来安断裂和无锡—宿迁断裂所夹持的区域,未来有发生Ms5.0级地震的构造背景,应关注其未来地震危险性。