Inorganic–organic hybrid coating‐encapsulated ammonium polyphosphate and its flame retardancy and water resistance in epoxy resin

A novel encapsulated ammonium polyphosphate (APP) with an inorganic–organic hybrid coating (MAPP) was prepared by a sol–gel method using tetraethoxysilane and octyltriethoxysilane as precursors. The properties of MAPP were investigated by water solubility, hydrophobicity, and morphological determination. The structure of MAPP was characterized by X‐ray photoelectron spectroscopy. The flame retardancy of epoxy resin composite with MAPP was evaluated by limiting oxygen index, UL‐94 test, and cone calorimetry test. The results showed that both tetraethoxysilane and octyltriethoxysilane hydrolyze and condense to form a dense polysiloxane layer structure on the surface of APP. The water solubility of MAPP was reduced from 0.64 to 0.13 g/100 mL of water, and the water resistance of epoxy resin composites filled with MAPP was also greatly improved. The limiting oxygen index, UL‐94 test, and cone calorimeter results showed that the epoxy resin composites filled with MAPP had better flame retardancy, probably because of a synergistic effect between polysiloxane and APP. Copyright © 2013 John Wiley & Sons, Ltd.     

Android和Iphone的技术对比

iPhone和Android都是时下最火的智能终端操作系统,自诞生之日起便深刻的改变了行业的格局并展开了激烈的竞争.两者可谓棋逢对手将遇良才,本文试从技术的角度对二者进行了一番对比并分析其未来的发展趋势.     

交互设计提升理财类APP可用性研究

目的通过研究提出交互设计原则,提升理财类APP的交互设计水平,进而提升其可用性。方法归纳理财类APP可用性目标,通过用户访谈与问卷调查的方式,探索用户行为习惯与使用偏好,提出基于可用性的理财类APP交互设计原则。对某财富APP进行再设计,使其遵循交互设计原则。对改良前后的设计进行可用性测试,被测试者分别使用改良前后的设计原型完成4组任务,统计并对比用户完成任务的操作时间、成功率、用户满意度,判断改良后的设计在可用性方面是否有所提升。结论理财类APP可通过包括符合用户心智模型的呈现形式、合理的信息搜寻路径与信息展示方式、确保可学习性、确保安全性、提升社交体验的方式提升交互设计,有效提升应用的可用性。     

基于Scrum的旅游类APP敏捷测试研究

随着旅游产业移动互联网大时代的到来,旅游类APP产品的数量正与日俱增,如何保障APP产品的质量成为其敏捷开发过程中不容忽视的重要环节.本文通过分析敏捷测试的研究现状,结合峨眉山智慧旅游APP项目阐述基于Scrum的敏捷测试实施流程,为敏捷测试在旅游类移动应用领域中的实践提供了参考.     

Polymer membranes for high temperature proton exchange membrane fuel cell: Recent advances and challenges

Proton-exchange membrane fuel cells (PEMFCs) are considered to be a promising technology for efficient power generation in the 21st century. Currently, high temperature proton exchange membrane fuel cells (HT-PEMFC) offer several advantages, such as high proton conductivity, low permeability to fuel, low electro-osmotic drag coefficient, good chemical/thermal stability, good mechanical properties and low cost. Owing to the aforementioned features, high temperature proton exchange membrane fuel cells have been utilized more widely compared to low temperature proton exchange membrane fuel cells, which contain certain limitations, such as carbon monoxide poisoning, heat management, water leaching, etc. This review examines the inspiration for HT-PEMFC development, the technological constraints, and recent advances. Various classes of polymers, such as sulfonated hydrocarbon polymers, acid-base polymers and blend polymers, have been analyzed to fulfill the key requirements of high temperature operation of proton exchange membrane fuel cells (PEMFC). The effect of inorganic additives on the performance of HT-PEMFC has been scrutinized. A detailed discussion of the synthesis of polymer, membrane fabrication and physicochemical characterizations is provided. The proton conductivity and cell performance of the polymeric membranes can be improved by high temperature treatment. The mechanical and water retention properties have shown significant improvement., However, there is scope for further research from the perspective of achieving improvements in certain areas, such as optimizing the thermal and chemical stability of the polymer, acid management, and the integral interface between the electrode and membrane.     

用聚磷酸铵和联二脲来提高绝热层材料耐烧蚀性能的研究

论述了固体火箭发动机用绝热层材料的烧蚀过程以及提高耐蚀性能的功能添加剂的种类和作用,在以聚醚型聚氨酯为基体材料的绝热层配方中,添加聚磷酸铵和联二脲,测试其质量烧蚀率和线烧蚀率。试验结果表明,聚磷酸铵和联二脲都能够提高绝热层的耐烧蚀性能,尤其在聚磷酸铵和联二脲以及一定比例复配时效果最好。     

纳米阻燃母液提高APP/PER/MEL防火涂料耐水性研究

用Solsperse17000超分散剂对纳米二氧化硅和纳米氢氧化镁表面进行包覆改性,再加入树脂、助剂等,经球磨和超声波分散制成纳米阻燃母液,并配制出不同纳米母液含量的纳米改性防火涂料.用透射电子显微镜分析(TEM)和红外光谱分析(FT-IR)研究纳米粒子分散状态和稳定机制.用红外光谱分析(FT-IR)、扫描电子显微镜分析(SEM)、浸水失重曲线分析、差热分析(DTA)研究在水介质中纳米改性防火涂料形貌变化、分子结构变化、水介质传输行为和浸水前后防火涂层的热降解行为.结果表明:4%纳米阻燃母液能有效提高APP/PER/MEL防火涂料的耐水性,且不损害它的热降解行为和防火性能.     

基于LoadRunner的移动端软件性能测试研究与应用

随着应用程序的不断普及以及越来越多的发移动端应用程序采用敏捷开发和迭代开,这使开发测试和运维的脱节,对应用系统的可用性、可靠性和性能提出了严峻的挑战。在移动应用程序的功能更复杂化的情况下,如何有效地提高移动应用软件性能,至关重要。文章针对实际的移动端软件APP进行移动应用性能测试的研究,基于LoadRunner和Dynatrace的结合来实现对移动端APP的性能测试,分析软件性能瓶颈,为进一步提高改善移动APP性能指标给出依据。     

室内环境无线监控系统的设计

针对室内环境传统有线监控的情况,设计了一种基于STM32的室内环境无线监控系统。系统以STM32微控制器为核心,使用人体红外传感器检测人流量,采用光敏传感器测量室内的光照度,结合MQ-2烟雾传感器及DS18B20温度传感器,并利用震动传感器来火灾和地震的发生。微控制器STM32获得室内的人数、光照度、烟雾浓度、震动强度和温度后,根据设定的程序将这些信息通过WIFI模块发送到手机APP,APP收到人数、光照度、烟雾浓度、震动强度和温度的信息后进行适当控制。如果出现问题,微控制器可驱动报警模块进行报警,以及进行灯光的合理调整,还可以将信息发送到TFT液晶显示屏上来检测。该系统有一定的应用价值。     

基于互联网的共享智能储物柜系统

共享智能储物柜可以极大地减轻学生群体背书去图书馆的双肩负担,有效规避图书馆占座、私人财产丢失等现象。基于此需求,利用基于游离态的多线程TCP/IP网络编程技术、iOS APP开发技术和嵌入式技术,设计了一个基于互联网的共享智能储物柜系统。在此系统下,用户直接通过手机APP便可以连接上文章中设计的多线程服务器进行储物柜的存取、支付相关使用费用等。测试结果表明,该系统达到了预期目标,而且APP漂亮、直观、易操作;设计出的服务器程序性能良好,具有良好的拓展性。