梁滩河生态系统健康评价研究

通过收集梁滩河流域的生态、经济和社会状况资料,并利用遥感解译技术,分析影响河流生态系统健康的因素,采用指标体系分析法和专家咨询法,确立梁滩河生态系统健康评价指标体系和评价标准,计算得出评价指标权重,并对河流生态健康状况进行了评价。结果表明:梁滩河上、中、下游生态系统分别处于"亚健康"、"不健康"和"亚健康"级别。该研究结论将为重庆市正在开展的梁滩河保护规划和治理工作提供科学依据。     

Density functional theory simulation of heterogeneous polymerization reactions during biomass hydrothermal carbonization

Carbonaceous microspheres formed through heterogeneous polymerization reactions during hydrothermal carbonization of biomass showed a considerable effect on the mass yield and physicochemical properties of hydrochar. In exploring the growth mechanism of carbonaceous microspheres, the heterogeneous polymerization reaction of four typical organic components (5-hydroxymethylfurfural, furfural, phenol, and p-xylene) with the surficial functional groups of carbonaceous microspheres was investigated using density functional theory (DFT). Nucleophilic addition and dehydration are the main forms of polymerization reactions, and the former shows a lower reaction energy barrier than the latter by 100 kJ/mol, indicating that the nucleophilic addition reactions likely occur compared to dehydration reactions. And phenol likely promotes the growth of microspheres. In addition, the surficial furan ring structure of carbonaceous microspheres opened through ring opening, hydrogen atom transfer, and molecular space structure conversion in sequence. Among these reaction steps, the furan ring opening through hydration was the rate-limiting reaction step, which showed the highest energy barrier with a value of 394.51 kJ/mol. However, the ring opening of furan rings could form more active sites, such as carbonyl groups, for subsequent polymerization reactions, indicating an increased potential for further reactions with aqueous-phase organic components.     

Metallurgical solid waste modified thermoplastic polyurethane composites: The thermal stability and combustion properties

As a kind of bulk industrial solid waste, the massive accumulation of iron tailings has caused serious waste of resources and environmental pollution. In this study, a silane coupling agent (KH550) was used to modify the surface of iron tailings to produce MIT, and it was compounded with ammonium polyphosphate (APP) on thermoplastic polyurethane (TPU) to prepare a series of TPU/APP/MIT composites. Thermogravimetric (TG), cone calorimetric (CCT), thermogravimetric infrared, scanning electron microscopy, and Raman techniques were also used to analyze the combustion performance, smoke toxicity, and microscopic morphology. The TG test results showed that the compounding of APP and MIT significantly improved the residual carbon value of TPU composites at 700°C. CCT test results showed that the TPU/APP/MIT composites exhibited excellent flame retardancy and smoke suppression. Compared with pure TPU, PHRR, THR, and TSR of TPU/APP15/MIT10 composite decreased by 85.56%, 87.83%, and 86.17%, respectively, the peak release rates of CO and CO₂ decreased by 69.26% and 90.34%, respectively. The above studies showed that APP and MIT have excellent flame retardant and smoke suppression effect on TPU materials, providing more opportunities for the study of TPU composites and metallurgical solid waste utilization.     

Adsorption dynamics of ethane from air in structured fixed beds with different microfibrous composites

Adsorption dynamics of ethane in two granular fixed beds and structured fixed beds with microfibrous composites was studied. 5A zeolite membrane 5A/PSSF(paper-like sintered stainless steel fiber) and microfibrous entrapped activated carbon(MEAC) composites were prepared by wet layup papermaking/sintering technique and in-situ hydrothermal method. Microfibrous composites were characterized by X-ray diffraction, scanning electron microscopy and N₂ adsorption/desorption. Structured fixed...     

防电磁辐射纺织品屏蔽效果测试

对防电磁辐射纺织品的开发情况进行了介绍，并对收集到的部分样品的防电磁辐射效果进行了测试，研究发现，不同处理方法的屏蔽效果有明显的差异，采用镀银，尤其是双面镀银织物，可以具有很好的屏蔽效果。     

应用于非开挖翻衬法管道修复技术的管状织物织造工艺

基于非开挖翻衬法管道修复技术对管状内衬复合材料的特殊要求,设计了一次成型的定径、分叉、弯径、三通和变径机织管状织物增强体的结构与织造工艺,对试织的管状织物的基本性能进行了测试与分析。结果表明采用聚酯弱捻长丝织制的几种管状织物厚度、密度、强力与弹性达到了翻衬法管道修复技术的工艺要求。     

天然抗氧化剂在油脂中的应用研究

本文介绍了油脂的天然抗氧化剂的种类，以及其抗氧化的机理和产生的效果，为以后的开发利用提供参考。     

对位芳纶纤维扭转疲劳断裂研究

利用自制的扭转疲劳装置对芳纶高性能纤维进行扭转疲劳测试，得出Twaron2000长丝纤维预加张力、扭转角与疲劳寿命的关系及几种对位芳纶纤维的扭转疲劳寿命对比结果。     

盐析辅助液液萃取-HPLC-MS/MS法检测液态乳中13种双酚类和烷基酚类物质

目的:建立盐析辅助液液萃取-HPLC-MS/MS法同时检测液态乳中13种双酚类和烷基酚类化合物的方法。方法:采用盐析辅助液液萃取前处理方法,三重四极杆质谱负离子源多反应监测(MRM)模式下进行检测,基质外标法定量分析;研究萃取溶剂种类、盐析助剂的选择和用量对回收率的影响;并评估方法性能。结果:以乙腈为提取溶剂、0.4 g氯化钠为盐析助剂对液态乳进行液液萃取,13种酚类物质线性关系良好,相关系数均＞0.99;牛奶和酸奶中的加标回收率分别为81.5%~118.1%和80.8%~107.6%,相对标准偏差分别为1.89%~12.3%和1.12%~11.9%;方法检出限为0.15~0.75μg/kg,定量限为0.5~2.5μg/kg。市售液态乳样品中有1个样品检出含有4-NP,含量为9.28μg/kg。结论:试验所建方法适合液态乳中13种双酚类和烷基酚类化合物的快速检测。