预制减震墙板加固震损框架抗震性能试验研究

本文中提出先对震损框架进行局部修复,再采用预制减震墙板进行加固的预制减震墙板加固震损框架的方法,设计制作震损修复框架(RBF)、预制减震墙板加固震损框架(DWF)以及预制普通墙板加固震损框架(CWF)3榀足尺试件,对其进行拟静力加载试验,对比研究3个试件的滞回性能、承载能力、破坏形态以及延性等抗震性能。结果表明：对震损框架进行局部修复,再采用预制减震墙板对其进行抗震加固可提高震损修复框架的抗侧刚度、承载能力和屈服后的变形能力;预制减震墙板加固震损框架(DWF)滞回曲线稳定、饱满,其承载力衰减缓慢,具有良好的持续抵抗外荷载的能力,不改变震损修复框架结构的受力和破坏特征,其变形能力满足GB 50011—2010《建筑抗震设计规范》罕遇地震作用下1/50层间位移角的要求,具有良好的抗倒塌能力;预制减震墙板单元与框架间的拉结筋构造措施提高了结构的整体性,保证了预制减震墙板既定的摩擦滑移耗能机制的有效实现。     

采用火焰焊补技术修补焦炉炭化室炉底破损

以某焦化厂焦炉炭化室为研究对象,分析了炭化室炉底破损的特点。在采用泥浆喷补法修补破损表面效果不佳后,改用火焰焊补方法。探讨了火焰焊补炉底破损表面的准备工作、焊补操作及后续工作,分析了火焰焊补过程中应注意的问题。火焰焊补后经过一段时间的运行,焊补部位平滑光洁,推焦操作电流稳定,出焦正常,推焦杆无明显振动,修补效果良好。     

超声检测混凝土硫酸盐侵蚀的研究

用超声波法对受硫酸盐侵蚀混凝土的表面损伤层厚度进行了检测，采用回归分析方法取代传统的作图法进行数据处理，并与受侵蚀混凝土的化学分析结果进行对比，标定超声检测混凝土腐蚀的程度和适用性，初步试验和研究表明，超声检测方法切实可行，可为混凝土耐久性无损检测工程提供参考。     

薄层水泥混凝土修补破损路面的方法研究

随着国家经济建设的快速发展和公路运输的繁忙.公路的破损现象越来越多,所以如何实现道路的快速的维修和抢修.已成为道路_T程值得-个研究的问题,再结合十几年工程实践经验,提出破损路面的修补方法,以供参考.     

基于防腐层电阻率的埋地管道防腐层退化规律

调研防腐层退化行为的研究现状,分析北京燃气防腐层应用现状,统计在役管道的土壤环境、杂散电流环境,结合历年防腐层电阻率及破损点检测数据,分析3PE及沥青类防腐层的.退化规律。研究得出:3PE防腐层材料较好,管段的平均防腐层电阻率随服役年限的变化较小,应重点考虑防腐层破损点的剥离情况,尤其在pH值较高、阴极保护、杂散电流干扰等多种情况叠加下的剥离风险。沥青类防腐层相对于3PE防腐层性能较差,由于服役年限较长及受各种因素影响导致防腐层电阻率较低,随着服役年限的增长,防腐层电阻率持续下降。沥青类防腐层由于破损点剥离程度随时间变化越来越严重,对于管段的平均防腐层电阻率有一定影响。对于防腐层退化规律的后续研究,应根据不同服役年限的防腐层试样,结合电化学阻抗谱、材料成分检测、材料性能检测等手段,分析防腐层性能的变化规律。     

Edible coatings enriched with essential oils for extending the shelf‐life of ‘Bravo de Esmolfe’ fresh‐cut apples

Edible coatings based on sodium alginate (AL) and pectin (PE) at 1% and 2%(w/v) enriched with eugenol (Eug) and citral (Cit) at minimum inhibitory concentrations (MIC) (0.10% and 0.15%) and double MIC were used to preserve the quality of fresh‐cut apples ‘Bravo de Esmolfe’. Samples were taken, through 14 day at 4 °C, for analysis of colour CIE(L*h°C*), firmness, °Brix, weight loss, antioxidant activity (TEAC), microbial growth and taste panels. With those quality characteristics, three groups were formed by the principal component and hierarchical cluster analysis, for each coating base (AL or PE). Based on, for each quality parameter measured, the mean closest value to the one at harvest for colour, higher value for firmness, °Brix and TEAC, and lower value for weight loss and microbial spoilage, the best group was selected for AL and PE. From each group, two edible coatings with the highest scores in overall acceptability were selected for fresh‐cut apples: AL2% + Eug 0.1%, AL2% + Cit 0.15% + Eug 0.1%, PE 2% + Cit 0.15% and PE 2% + Eug 0.2%.     

Efficacy of thyme oil-alginate-based coating in reducing foodborne pathogens on fresh-cut apples

In this study, the inhibition of an alginate-based edible coating (EC) containing thyme oil (0.05%, 0.35% and 0.65%) was evaluated against Listeria monocytogenes, Salmonella Typhimurium, Staphylococcus aureus and Escherichia coli O157:H7 inoculated onto fresh-cut apples. To investigate the antibacterial mechanism of thyme oil, the constituent compounds of that were analysed by gas chromatography-mass spectrometry (GC-MS), and the cellular damage of pathogens was observed by scanning electron microscopy (SEM). Results showed that alginate-based EC containing thyme oil effectively inhibited the growth of pathogens on fresh-cut apples. GC-MS analysis revealed thymol (47.23%) as the major compounds in thyme oil. SEM showed that the cell membrane of foodborne pathogens was damaged by thyme oil, causing their inactivation. Treatment with alginate-based EC containing 0.05% thyme oil preserved the sensory characteristics of fresh-cut apples. Therefore, using alginate-based EC with thyme oil may represent a potential approach to preserve and enhance the safety of fresh-cut apples.     

A profile of physicochemical and antioxidant changes during fruit growth for the utilisation of unripe apples

The physicochemicals associated with fruit quality, antioxidant activities and changes in polyphenol composition during Fuji apple growth were investigated from the 25th to 105th day after full bloom day (DAFB). Three kinds of antioxidant assays, including oxygen radical absorbing capacity (ORAC) were executed, and polyphenol composition were examined using HPLC. The change in weight of the Fuji apples during fruit growth showed a typical sigmoidal curve. Both the rise of the soluble solid content and the drop of the titratable acidity appeared to be more significant (p < 0.05) after the 85th DAFB. Concurrently, the antioxidant activities and the polyphenol content decreased (p < 0.05) rapidly after the same date. Accordingly, a profitable thinning date can be chosen around the 85th DAFB to utilise dropped unripe apples as resources of antioxidants. Furthermore, the antioxidant activities of Fuji apples may be highly affected by the chlorogenic acid content.