A field operational test on valve-regulated lead-acid absorbent-glass-mat batteries in micro-hybrid electric vehicles. Part II. Results based on multiple regression analysis and tear-down analysis

In the first part of this work [1] a field operational test (FOT) on micro-HEVs (hybrid electric vehicles) and conventional vehicles was introduced. Valve-regulated lead-acid (VRLA) batteries in absorbent glass mat (AGM) technology and flooded batteries were applied. The FOT data were analyzed by kernel density estimation. In this publication multiple regression analysis is applied to the same data. Square regression models without interdependencies are used. Hereby, capacity loss serves as dependent parameter and several battery-related and vehicle-related parameters as independent variables. Battery temperature is found to be the most critical parameter. It is proven that flooded batteries operated in the conventional power system (CPS) degrade faster than VRLA-AGM batteries in the micro-hybrid power system (MHPS).A smaller number of FOT batteries were applied in a vehicle-assigned test design where the test battery is repeatedly mounted in a unique test vehicle. Thus, vehicle category and specific driving profiles can be taken into account in multiple regression. Both parameters have only secondary influence on battery degradation, instead, extended vehicle rest time linked to low mileage performance is more serious.A tear-down analysis was accomplished for selected VRLA-AGM batteries operated in the MHPS. Clear indications are found that pSoC-operation with periodically fully charging the battery (refresh charging) does not result in sulphation of the negative electrode. Instead, the batteries show corrosion of the positive grids and weak adhesion of the positive active mass.     

Electrospinning fabrication and characterization of poly(vinyl alcohol)/waterborne polyurethane nanofiber membranes in aqueous solution

Poly(vinyl alcohol) (PVA)/waterborne polyurethane (WBPU) nanofiber mats were prepared using electrospinning method with aqueous solutions. Scanning electron microscopy (SEM), X‐ray diffraction (XRD), thermal gravimetric analyzer (TGA), and tensile strength testing machine (ZWICK) were used to characterize the morphology and properties of the PVA/WBPU nanofiber mats. The results showed that the morphologies of PVA/WBPU nanofiber mats changed with the total solid concentration and the mass ratio of PVA/WBPU in the spinning solution. The tensile strength and thermal stability of the fibers could be significantly affected by the WBPU contents. The electrospun PVA/WBPU membranes showed higher water uptake, which would have potential applications in wound dressings. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

静电纺丝法制备PLA荧光纤维膜的研究

采用掺杂的方式,分别将纳米无机荧光染料钨酸盐（Eu2WO6）和对位取代氨基苯乙烯吡啶衍生物（DH-EASPT-C1）掺入聚合物PLA中配成静电纺丝液,利用静电纺丝法制备成荧光纤维膜。利用UV-VisTu-1800spc紫外分光光度计、Edingburgh920单光子稳态／瞬间荧光光谱仪、S-4700冷场发射扫描电镜（S...     

论高层建筑消防电气防火设计和施工

本文结合高层建筑的施工建设实际情况,对其施工建设中的消防电气防火设计与施工建设注意事项进行了分析和论述,希望能够促进高层建筑施工建设的发展与提升。     

道床隔振垫的阻尼减振性能分析及应用研究

对道床隔振垫进行了在静态状态下锤击试验和在车辆正常运行条件下的轨道动态变形及振动测试,结果表明,道床隔振垫实际应用时的隔振频率在10—15 Hz之间。在静态条件下,相对于单趾弹簧扣件系统在20—200 Hz频率范围内,平均减振量为16.3 d B;在车辆运行条件下,隧道壁的垂向振动降低了17.3 d B。在静态和动态条件下,相对于单趾弹簧扣件系统,道床隔振垫减振效果基本一致。     

粘结剂在玻纤毡生产中的应用

随着玻璃纤维短切毡在工业上的大量应用，其所用的粉末粘结剂理论和使用技术得到飞快发展。如何控制好粉末粘结剂的使用和选用对制毡至关重要，本文就粘结剂的选用和生产控制方法作一介绍。     

崖上村隧道复合式衬砌初期支护的施工

结合崖上村隧道施工工程概况,介绍了喷混凝土、锚杆、加设钢筋网、格栅钢架施作等各施工环节的施工技术,并对初期支护的施工工艺、技术参数等均做了详细阐述,以供同类工程参考.     

连续玻璃纤维毡/聚酯绝缘型材的性能研究

采用拉挤法制备连续玻璃纤维毡(CFM)增强不饱和聚酯(UP)绝缘(CFM/UP)型材,研究了玻璃纤维含量对CFM/UP型材力学性能的影响,并探讨了连续玻璃纤维毡用粘结剂含量对CFM/UP型材常温和130℃下弯曲性能的影响。结果表明:CFM/UP型材力学性能随着玻璃纤维含量的提高呈上升趋势。当纤维填充质量分数为46%,粘结剂的质量分数为5%时,CFM/UP型材的弯曲强度最佳,CFM/UP型材的力学性能和电性能数据均达到GB/T 1303.7-2009的要求。     

短切毡用乳液粘结剂PVAc乳液的合成改性

从配方和工艺两方面着手,为制备出渗透快、内增塑的柔软性优良的无碱玻璃纤维短切毡粘结剂,研究了粘结剂配方中丙烯酸用量、自制内增塑单体配比、单体的加料顺序等对粘结剂性能的影响,而且考察了引发剂用量与反应温度的关系。结果表明丙烯酸为1%,内增塑单体复配配比为10:5、单体的加料顺序为软硬软时所得粘结剂性能最佳。并进行了工业化的中试试验。     

玻璃纤维增强热塑性片(板)材发展概况

分别介绍了国外3种玻璃纤维增强热塑性塑料产品即玻纤毡增强热塑性片材、短纤维增强热塑性片材和连续纤维增强热塑性片(板)材的发展概况、品牌产品、主要性能和用途,以期对我国玻璃纤维增强热塑性塑料产品的开发有所参考.