纤维复合材料布加固混凝土梁受剪性能的试验研究

本文介绍了8根GFRP布、1根CFRP布加固混凝土梁以及1根未加固对比梁的受剪试验,研究了FRP布受剪加固形式、加固量、剪跨比、FRP材料类型等对受剪性能的影响,着重研究了U型FRP布受剪加固的剥离破坏性能和承载力。根据FRP布应变的试验实测结果,分析了剥离破坏时FRP布的有效发挥程度及其对受剪承载力的贡献,提出了U形FRP布受剪加固混凝土梁剥离承载力的计算公式。     

Temporal trends of nonylphenol and bisphenol A contamination in the Pearl River Estuary and the adjacent South China Sea recorded by dated sedimentary cores

Three dated sedimentary cores were collected for the investigation of temporal trends and the environmental loadings of nonylphenol (NP) and bisphenol A (BPA) in recent decades in the Pearl River Estuary (PRE), South China and the adjacent South China Sea (SCS). The peak fluxes of NP and BPA occurred in the mid-1980s in the PRE, coincident with the rapid economic growth in China. The decline of NP and BPA fluxes is attributable to the implementation of sewage treatment in the late 1980s in the Pearl River Delta (PRD). Multi-model distributions were observed for the fluxes of NP and BPA in the SCS with the peak fluxes occurring in the late 1950s and the mid-1970s respectively. The fluxes of NP and BPA have increased since the 1990s due to the lack of adequate wastewater treatment facilities and the constant economic growth. Nonylphenol was quantifiably detected in sediments predating its widespread application (1940s), suggesting the downward penetration of NP in the sediment columns. The characterization results revealed that NP and BPA were preserved well and the isomer-selective degradation of NP did not occur significantly in the sediment cores. The environmental loadings of NP and BPA in the PRE sediments were roughly estimated to be 124 t and 1.7 t respectively over the past 30 years.     

Stir bar sorptive extraction and trace analysis of selected endocrine disruptors in water, biosolids and sludge samples by thermal desorption with gas chromatography-mass spectrometry

Stir bar sorptive extraction (SBSE) in combination with thermal desorption coupled to gas chromatography-mass spectrometry (GC-MS) was successfully applied to analyze a range of endocrine disrupting compounds (EDCs) in wastewater, solids and sludge. The targeted EDCs include sex steroid hormones, phthalates, alkylphenols and tamoxifen. Recovery for the EDCs using this analytical technique ranged from 44% to 128%. Limit of detection (LOD) of the compounds was 2.0 ng/L for water samples and 0.02 ng/g for solid samples, whereas the limit of quantitation (LOQ) was 5.0 ng/L for water samples and 0.06 ng/g for solid samples. When this analytical technique was applied to measure EDC concentration in a biological nutrient removal (BNR) wastewater treatment plant located in South East Queensland, Australia, the results showed that there were high amounts of phthalates, alkylphenols and female hormones present in the raw influent wastewater and solids. These concentrations were dramatically reduced after passing through the various treatment zones of the bioreactor (anaerobic, aerobic and anoxic).     

浴室干燥热泵热水器实验研究

设计了一款具有除湿功能的浴室干燥热泵热水器,分析了系统结构和工作原理。对不同运行模式的实验研究表明,该热水器在节能与功能方面具有独特的优势。     

国家体育场安全疏散设计

结合国家体育场设计实践,在国内首次对国际先进的体育场馆设计准则"8min疏散原则"进行了系统阐述.并对国家体育场设计中应用的计算机模拟安全疏散设计方法进行了归纳,对国内体育场馆规范的发展和体育场馆设计具有重要的参考作用.     

论现行大遗址保护规划体系的完善

结合大遗址保护的重要作用和意义,针对大遗址保护目前存在的层次不清,缺乏针对性,内容模糊等问题进行了分析,提出了大遗址保护规划体系的三项完善措施,以期形成有效的保护管理机制,完善现行的大遗址保护规划体系。     

工业厂房结构形式与其抗震性能的关系分析研究

主要基于对四川灾区工业企业厂房受灾情况的调研,在汇总分析不同结构形式排架厂房的震害特点的基础上,分析了各结构构件对厂房受损的影响,讨论了其抗震性能与结构形式的关系。     

1-H苯并三氮唑乙酸酯的合成、表征及其摩擦学性能

苯并三氮唑具有良好的摩擦学性能, 但在矿物油中的溶解性较差.为提高其在矿物油中的溶解性,采用1-H苯并三氮唑与氯乙酸酯进行取代反应,合成了3种1-H苯并三氮唑乙酸酯新型润滑油添加剂,用IR、UV、1H NMR、13C NMR、MS和元素分析对其结构进行了分析表征,确证了其结构.利用四球试验机考察了其在液体石蜡中的最大无卡咬负荷值.结果表明:合成的3种化合物均能溶于大部分有机溶剂而难溶于水;热失重分析结果表明,第一分解温度均高于218 ℃,能适应一般工况条件的要求;3种化合物在液体石蜡中有良好的极压抗磨作用,最大无卡咬负荷值可达862 N,与二烷基二硫代磷酸锌(ZDDP)相当.     

聚乙烯表面紫外光接枝MPC及其性能研究

将所合成的生物相容性单体2-甲基丙烯酰氧乙基磷酸胆碱(MPC) 通过紫外光接枝到聚乙烯表面,以改善其表面的润滑性、生物相容性以及耐磨性.通过IR、ATR-FTIR、XPS、SEM以及722分光光度计等手段检测了接枝前后聚乙烯样品的相关性能,并研究了接枝前后聚乙烯样品在蒸馏水、生理盐水润滑下的摩擦磨损性能.结果表明,聚乙烯表面可接枝MPC,且接枝量随光照时间的增加而增大;接触角由64°～76°变成15°～26°,接触角大小随接枝量的增大而减小;接枝后样品的溶血率比接枝前低,且样品表面几乎没有血小板;接枝后样品摩擦因数变小,体积磨损率降低.     

基于面积误差评价的轨迹跟踪数字式最优预见控制

研究在数字最优预见控制中以面积误差作为评价函数的轨迹跟踪最优预见控制方法。首先 ,分析了轨迹跟踪控制的特点和一些问题 ,依次建立了基于面积误差的轨迹跟踪性能评价函数 ,从而获得轨迹跟踪的最优预见控制算法 ;然后对一个简易工作平台系统的轨迹跟踪问题进行了仿真验证。结果表明基于面积误差评价的最优预见控制方法是能够提高路径控制精度的一种有效方法。