Ce~(3+)及B~(3+)共掺杂纳米SiO_2的光致发光性能

采用溶胶-凝胶法并结合后续700～1000℃热处理制备Ce3+、B3+共掺纳米SiO2材料。用X射线衍射(X-ray diffraction,XRD)、透射电子显微镜(transmission electron microscope,TEM)、X射线光电子能谱、紫外-可见吸收光谱仪(ultraviolet-visible spectrophotometry,UV-Vis)及荧光光谱仪表征材料的结构、形貌、成分、光吸收及光致发光性能。XRD及TEM分析结果表明:该纳米材料具有非晶态结构,一次颗粒尺寸为10nm左右。UV-Vis吸收光谱显示:共掺样品在紫外区有吸收峰,其主吸收峰位于225nm和260nm。荧光光谱分析显示,经过H2气氛处理的样品中存在两套光致发光谱:一套为258nm激发产生的363nm紫外发光;另一套为317nm激发产生的407nm的宽带发光。对比分析经过不同温度处理以及不同B3+掺量样品的发光光谱,初步探讨两发光峰的起源。     

Molecularly imprinted polymer microspheres derived from pickering emulsions polymerization in determination of di(2‐ethylhexyl) phthalate in bottled water samples

The mono‐dispersed macroporous Molecularly Imprinted microspheres (MIPMs) selective for Diethylhexyl Phthalate (DEHP) were synthesized by Pickering emulsion polymerization. Silica nanoparticles were stabilizers in forming a stable oil‐in‐water emulsion, while the polymeric system was prepared by radical polymerization using methacrylic acid as functional monomer and ethylene glycol dimethacrylate as cross‐linker. The results of scanning electron microscopy and nitrogen adsorption desorption measurement indicated that the obtained polymer microspheres had regularly porous structure and narrowly diameter distribution (100 nm), besides the specific surface area (S_BET) was 452 m² g^?1, pore volume was 9.685 cm³ g^?1, and pore diameter was 5.089 nm. The equilibrium adsorption capacity of MIPs was 1.75 mg g^?1 at 298 K. Good selectivity for DEHP in another two kinds of analogies (DBP and DAP) was demonstrated with high selectivity coefficients, respectively 17.753 and 19.450. In the end, DEHP‐MIP was used as packing of solid‐phase extraction to form an sensitive analytical method in extraction and enrichment DEHP in bottled water samples with the limits of detection of 1.7–2.5 μg L^?1.The recoveries at three spiking level (0.05, 0.1, and 1 mg L^?1) were varied between at 97.5 and 103.1% with RSD values below 3.5. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43484.     

丙烯氧化制环氧丙烷研究进展

环氧丙烷 (PO)是重要的有机化工原料和中间体 ,目前工业采用氯醇法和间接氧化法生产。这两种方法均存在严重缺陷 ,有待于改进。本文主要介绍丙烯直接氧化法制取PO的近期进展 ,指出了丙烯直接氧化法研究的难点和今后研究的方向。     

化工警报系统可靠性评估

提出了一种基于区间模糊集和证据推理方法的评估化工警报系统可靠性的新方法。在这种方法中 ,化工警报系统中各组成部分及部件的可靠性用区间模糊语言变量来表示 ,利用证据推理方法合成各子系统部件的可靠性评估结果 ,提高了各子系统的可靠性水平。文中以某工厂化工警报系统的可靠性评估阐述了该方法的应用情况。     

Development of 1D model for the analysis of heat transport in cylindrical micro combustors

A 1D flame model was developed to analyze the heat transport occurring in the cylindrical micro combustors. The one-step global reaction mechanisms were employed for three fuel–air mixtures (H₂–air, CH₄–air and C₃H₈–air) to account for the difference of fuel property in terms of the kinetics. The effects of various parameters such as the combustor size, fuel property, fuel–air equivalence ratio and unburned mixture temperature on the heat loss ratio (defined as Q_l/Q_in) and the heat recirculation ratio (defined as Q_recir/Q_l) were investigated. The results indicated that these parameters have significant effects on the two ratios, and therefore should be carefully managed in order to achieve efficient and stable combustion. After comparing the results of different fuel–air mixtures, it is concluded that hydrogen is superior to methane and propane as the fuel for micro combustion engines owing to its higher flame temperature and thinner flame thickness, which favors the reduction of heat loss from the flame zone.     

甲苯选择氧化制苯甲醛的研究进展

甲苯直接氧化制备苯甲醛是一条最为简单而经济的生产工艺。简要介绍了生产苯甲醛的传统工艺,综述了近几年国内外甲苯气相氧化法、液相氧化法的工艺条件及其催化剂的研究进展,阐述了甲苯控制氧化合成苯甲醛热力学理论基础与甲苯控制氧化合成苯甲醛的机理研究现状。     

水系有机液流电池活性材料的分子工程研究进展

氧化还原液流电池(RFB)是有良好发展前景的电化学储能技术和大规模可再生能源存储的有效解决方案,其中水系有机氧化还原液流电池(AORFB)不仅成本低,还可以通过分子工程进行活性材料的理性设计,从而高效率地得到具有精准目标性能的新型活性材料。综述了AORFB活性材料的发展历程和研究现状,重点对不同结构活性材料的分子工程研究进行介绍。结合当前研究趋势,提出了活性材料分子工程研究未来发展的方向与思路。     

亚毫米平行板通道内燃烧过程的数值模拟

微动力系统是动力机械具有里程碑意义的发展.由于能量密度的极大优势,应用燃烧释放碳氢燃料的化学能转化为电能或者机械能的微动力系统有巨大的发展潜力和广阔的应用前景.微燃烧室是该类微系统的核心,本实验建立了1mm以下尺寸的平行板微燃烧室内的流动、传热和燃烧模型,在实验验证的基础上,用CFD软件进行了数值模拟,获得了亚毫米平行板通道高度、混合气流量和比率等参数对内部燃烧情况及壁面温度的影响规律.     

江西白垩系泥质粉砂岩崩解试验研究

对南昌地区泥质粉砂岩典型出露地段开展现场调研并取样测试其基本物理力学性质,同时进行了静态崩解试验和岩石的耐崩解试验,从能量耗散原理的角度分析了泥质粉砂岩静态崩解过程中吸收的能量向表面能转化的规律。试验结果表明:水和温度—岩的相互作用是加快泥质粉砂岩风化的主要外部营力;泥质粉砂岩的静态崩解由碎块状过渡到粒渣状、泥糊状,可按崩解物形态划分为剧烈崩解、细微崩解和崩解稳定三个阶段,崩解过程中其表面能累计增加量随崩解次数增加而增加,而单次表面能增量趋于减小;耐崩解试验中,泥质粉砂岩耐崩解性指数随循环次数的增大呈负指数关系递减。试验结果对于工程实践中如何抑制红层软岩崩解并保持其完整承载能力、或对其预崩解处理促进其快速崩解达到稳定的颗粒级配状态具有一定的参考价值。