A study of 3D cover glass design that improves handheld device drop reliability

Cover glass in commercial handheld devices is now evolving from flat (2D) to curved (3D) shapes. For example, some commercial devices have utilized sled‐shape cover glass, 1 which partially covers long edges of the device. According to the patents published by key handheld manufacturers, 2 , 3 we can expect more variety of 3D shaped cover glass for handheld devices in the market. In this study, we have focused on the reliability of 3D cover glass when it is dropped to a rigid surface. The key parameters under study are the corner/edge bend radius and angle of the cover glass, which determines the 3D shape of the cover glass. To achieve this goal, we developed a finite element model to simulate the drop 4 - 13 of a handheld device with 3D‐shaped glass. The model uses explicit algorithm to simulate the high speed impact on the device during the drop test. The glass performance was evaluated based on contact force between the glass and the ground and maximum principal stress in the glass. We showed that to avoid severe damage because of first impact between the glass and the ground, the bend angle of 3D glass has to be in the range between 0 and 45°. For drop angles of 45° and higher, with the proposed glass bend angle, the impact can be taken over by the edge of the back cover of the device. In addition, we showed that optimum glass bend radius is in the range of 3.8 mm and larger. This is required to reduce stress in glass because of impact. The approach and conclusions from the current study can serve as a general guideline to improve the 3D cover glass reliability of a handheld device.     

基于PLC的灌溉施肥控制系统的设计与实现

针对传统农田灌溉施肥存在的浪费水资源、液体肥不均匀等问题,提出利用欧姆龙SYSMAC C系列可编程控制器和组态王6.55监控软件设计一套PLC灌溉施肥控制系统,利用传感器采集数据控制农田按需灌溉、按量施肥,实现自动灌溉施肥和监控管理,节省人力、实用性强。     

电力抄表催费计件绩效管理探析

介绍了岗位岗级绩效管理抄表催费中存在的问题,提出了计件绩效管理模式及其实践操作方式,并分析了电力抄表催费计件绩效管理的优势,以供有关单位参考。     

浅谈窃电、防治窃电措施和检查步骤

随着我国经济的快速发展,人们对电力资源的需求量越来越大。一些用户在利益的驱使下,为了减少电费开支,常采用一些不法手段窃电,这极大地降低了电力企业的经济效益,对电力企业的发展造成了很大的影响。通过分析常见的窃电手法,提出了一些防治窃电的措施。     

电波流速仪流量自动在线监测装置设计与应用

电波流速仪因其在测量过程中不受水情、含沙量及水面漂浮物的影响,因此近年来在水文部门得到了广泛应用。介绍了一种电波流速仪流量自动在线监测装置的设计方案,包括监测装置硬件和软件实现过程。将该装置应用于四川内江水文站实际测流工作,结果表明,使用电波流速仪的自动在线监测装置测流结果可靠,有利于提高效率和降低成本。可推荐类似水文测站采用。     

基于Android平台与SMS的智能家居能量管理系统

基于Android平台与SMS技术,设计并实现了智能家居能量管理系统设计方案。在文中描述了该系统的总体设计框图、终端软件设计、智能电表设计、智能插座设计。对该系统进行了验证,实验结果表明,该方案能够快捷地实现对家居设备等能量消耗单元的控制,成本很低,适合入门者使用。     

水肥处理对辣椒保护地土壤pH值的影响

探讨辣椒保护地的水肥耦合效应,采用二次回归正交旋转组合设计,建立了灌水定额、氮肥和磷肥对辣椒保护地土壤pH值影响的数学模型。通过模型分析得出:在辣椒保护地土壤养分含量高和施肥量大的条件下,灌水定额、施氮和施磷对辣椒保护地土壤pH值影响的大小顺序为:灌水>施氮>施磷。大量施用氮肥可使土壤酸化,灌水和高量施磷可减弱酸化效应,灌水与施氮、施氮与高量施磷对土壤pH值表现为拮抗作用。维持保护地土壤pH值种植前后稳定的水肥措施:灌水定额为170.71 m3/(hm2.次),施氮量为235.98 kg/hm2,施P2O5为239.38 kg/hm2。合理的施肥和灌水,可以控制土壤的酸化。     

汽车发动机冷却循环系统模块调温器总成试验台的研制

本文对汽车发动机冷却循环系统中模块调温器总成试验台的研制进行了阐述,对调温器的原理,主体结构与功能以及模块调温器总成试验台的装夹模具,温度、流量、压力检测分别作了介绍。     

全电池供电分线式智能水表抄表系统

全电池供电分线式智能水表抄表系统适用于水表出户集中放置或高层住宅层问穿线困难的使用环境。该系统采用高可靠双干簧管发信基表,并配置了采用专用集成电路而非单片机的智能数字式水量采集模块,具有抄读率高、功耗低、全电池供电、长期运行稳定、可靠的突出优点。     

基于嵌入式Linux的远程抄表系统集中器的实现①

通过分析比较国内外各种现有远程抄表系统的优点和不足,结合当前计算机技术和通信技术的发展和作者的实践经验,实现一种基于S3C2440处理器和嵌入式Linux的设计方案;具体说明了该方案的系统架构,并详细介绍了集中器嵌入式软件实现的关键技术。