泡沫混凝土配合比的设计

在研究泡沫混凝土各种原材料性能及大量实验和中试生产实践基础上,运用数理统计归纳分析,设计出既能满足泡沫混凝土干密度、导热率、强度、浇筑稳定性等技术要求,又经济合理、易于操作的各种原材料配合比,达到控制泡沫混凝土导热系数和抗压强度的目的,进而指导泡沫混凝土生产工艺过程,确保产品质量.     

季铵卤化银的制备及其热分解特性(英文)

季铵盐如十六烷基三甲綦经铵(CTAB)或十六烷基碘化铵(CTAI)与硝酸银反应得到新的沉淀物A,B,C和D。测试沉淀物的元素组成以及XRD,TG-DTA和IR,表明沉淀物是不于卤化银的新的化合物,暂时叫做季铵卤化银如十六烷基三甲基溴化银铵或十六烷基三甲基碘化银铵。分子式是A:C19H42NAg2Br3;B:C19H42NAgBr3;C:C19H42NAg2I3;和D:C19H42NAgI2;.我们季铵卤化银是季铵阳离子部分取代卤化银分子中的银离子的结果。     

载银活性炭/超滤组合技术去除溶解性有机物

为了强化水中溶解性有机物的去除效果,采用载银粉末活性炭与超滤( ultrafiltraction,UF)组合工艺处理微污染原水,研究了溶解性有机炭( dissolved organic carbon,DOC)和紫外吸光度( ultraviolet absorbance,UV254)的去除效果、三维荧光特性、影响因素以及膜污染控制的影响.研究结果表明：与常规粉末活性炭相比,载银活性炭对DOC和UV254的去除效果有较显著改善;在载银量0.10%、0.50%、1.00%和投炭量50、60、80、100 mg/L的条件下,随着活性炭载银量和投炭量的增加, DOC和UV254去除率呈现增加的趋势;单位质量的载银活性炭对UV254和DOC的去除率随投炭量的增加而下降,投炭量80 mg/L、载银量0.50%符合出水水质要求;载银粉末活性炭可以更有效地去除紫外区类腐殖质物质;吸附时间20 min时达到吸附平衡,活性炭在酸性条件下更有利于对有机物的吸附.载银活性炭对膜污染的控制较好,超滤膜经反洗后膜通量恢复较好,膜污染指数增长缓慢.     

微波合成SiO2气凝胶核/聚苯乙烯壳微球研究

将水玻璃为硅源所制备的纳米孔硅气凝胶与苯乙烯单体用微波加热合成法制备出SiO2气凝胶核/聚苯乙烯壳复合微球.用顺序间隔取样测试方法试验复合微球的密度、转化率和包覆率与微波合成温度、时间和聚合体系各组分变化情况,分析讨论了影响变化因素和原因.通过TEM和FE-SEM对复合微球进行结构与形貌表征.结果表明,优选体系组分配比为SiO2气凝胶3g、苯乙烯21g、乙醇水溶剂配比为380g∶20g、引发剂4.2g及稳定剂2g,微波合成工艺参数为加热功率500W,加热时间40min、加热温度60℃.在此工艺条件下合成,复合微球合成转化率是67.1%、包覆率为32.7%,制备出的核壳结构复合微球的粒径约为100~200nm、震实密度为0.353g/cm3,且表面凹凸不平状似"草莓"的微粒.     

厂拌泡沫沥青冷再生混合料在城市路面改造中的应用

泡沫沥青冷再生技术是一项绿色环保技术。文中简要介绍了泡沫沥青冷再生的作用机理和厂拌泡沫沥青冷再生混合料施工工艺流程,结合沧州市解放路的路面改造工程的施工,论述了泡沫沥青冷再生混合料的组成设计和路面施工方法,总结了泡沫沥青冷再生施工工艺的质量控制要点。     

Surface plasmon resonance-induced Ag-BaTiO3 composites for catalytic performance

Ferroelectric BaTiO₃ was combined with Ag nanoparticles for piezocatalytic and photocatalytic viewpoints. Microstructural characterization (X-ray diffraction and electron microscopy images) revealed that the Ag was successfully bounded with BaTiO₃. X-ray photoelectron spectrum also confirmed the presence of Ag. Further, its performance was examined for dye degradation under visible light (for photocatalysis) and ultrasonication (for piezocatalysis). In both the catalysis processes, there was a significant improvement in Ag-loaded BaTiO₃ sample-based catalytic reactions. Catalytic performance was evaluated for multiple cycles and was found consistent. Scavenger tests were also performed to understand catalytic reactions.     

One pot synthesis of nano Ag in calcium alginate beads and its catalytic application in p‐Nitrophenol reduction with kinetic parameter estimation and model fitting

In this work, one step process of synthesis of silver nanoparticles (Agnp) embedded in insitu formed calcium alginate (CA) beads is stated. CA, formed from the reaction between sodium alginate and calcium hydroxide, acts as reducing and stabilizing agent as well as support for nanoparticles. The reaction mechanism for the formation and stabilization of Agnp is proposed where the vicinal dihydroxy groups of alginate are assumed to act as the reducing agent for Ag⁺ to Ag°. Transmission electron microscopy (TEM), x‐ray diffraction (XRD), UV‐vis spectroscopy, field emission scanning electron microscopy (FESEM), and atomic absorption spectroscopy (AAS) were used to characterize the Agnp. The formation of spherical nanoparticles with average size range of 4‐5 nm was confirmed by TEM. Catalytic activity of this nano silver‐calcium alginate (Agnp‐CA) composite was evaluated in the reduction of p‐nitrophenol. Concentrations of sodium alginate, calcium hydroxide, and AgNO₃ are found to be the parameters that critically affect the synthesis of Agnp. The efficacy of the catalyst is expressed on the basis of suitable reaction parameters. Both pseudo‐homogeneous and heterogeneous kinetic models are proposed for the reaction to find the best model and the Eley‐Riedel model is found to fit well with the experimental data. The novelty of this work is that the tandem process of CA bead formation, Agnp formation, and Agnp entrapment in CA have been transformed into a single‐step process. Moreover, elaborations of each step of the ionic mechanisms of Agnp formation and p‐NP reduction with Agnp and the establishment of a heterogeneous kinetic model for the reaction are reported for the first time here.     

Removal behavior and mechanism of silver from low concentration wastewater using cellulose aerogel modified by thiosemicarbazide

Due to the low concentration of silver in water, most of the cellulose adsorbents exhibited low removal efficiency, which greatly limited their practical applications. Herein, a cellulose aerogel modified by thiosemicarbamide (CAT) was fabricated for reducing and adsorbing silver ions from low concentration wastewater. The characterization results concluded that CAT owned a three-dimensional spongy structure with many circular microspheres and a better specific surface area (19.37 m² g⁻¹), as well as the functional groups of ─C═N⁺─H and ─(C═S)─N. The static batch adsorption experiments demonstrated that CAT could reached the maximum removal percentage of 94.94% and adsorption capacity of 42.12 mg g⁻¹ under the initial concentration of Ag(I) was 15 mg L⁻¹ and the pH value was 7. Meanwhile, the adsorption of Ag(I) on CAT was second-order reaction, and the Langmuir model could better fit the adsorption process. In addition, CAT exhibited wide pH values (1–9) adaptability and excellent adsorption performance for silver through electrostatic interaction, chelation, and reduction. This study probably provides a new method as well as important experimental data and theoretical reference for the removal of silver ions and other metals.     

直流电弧等离子体法制备超细Ag粉研究

采用自行研制的高真空双枪直流电弧金属纳米粉连续制备设备,制备了高纯度的超细银粉,并采用正交试验的方法研究了各工艺参数对粉体产率及粒径分布的影响。利用X射线衍射（XRD）、透射电子显微镜（TEM）和相应选区电子衍射（SAED）以及Simple PCI软件对样品的成分、形貌、晶体结构和粒径分布进行了分析。结果表明：所得银粉纯净无污染,属多晶型结构,平均粒径在38-220nm范围内,粒径分布窄;最大产率比同类研究结果提高了近17倍;电流和充气压力分别是影响产率和粒径分布的显著性因素。     

基于比表面积计算的泡沫铝彩色处理时的电流控制

对泡沫铝进行彩色处理可能美化外观且改善其防护性能。试验表明，泡沫铝的表面处理工艺与铝材的大致相同，在此工艺中泡沫铝的比表面对电流值的影响是关键因素。利用泡沫铝透气系数正确计算其比表面积，从而得到有效的电流值。把电流值控制在该范围内，可得到氧化膜厚度大致为15μm，且着色色泽均匀。