ZrO_2(3Y)/Fe_3Al复合材料的裂纹扩展阻力曲线与增韧机制

通过压痕小裂纹法测量了ZrO2(3Y)/Fe3Al复合材料的R曲线,并利用显微Raman光谱和XRD测试了ZrO2(3Y)/Fe3Al复合材料的相变高度(h)和可相变体积分数((?)f),定量探讨了ZrO2(3Y)/Fe3Al复合材料中相变增韧和桥联增韧2种机制对增韧的贡献。结果表明:Fe3Al的加入使相变高度h和可相变体积分数(?)f明显提高,当Fe3Al含量为30％(体积分数,下同)时,h由单相ZrO2(3Y)的12μm提高至21μm;(?)f由单相ZrO2(3Y)的19％提高至30％,h和(?)f的增大使相变增韧效应增高。Fe3Al的桥联效应及相变增韧效应使ZrO2(3Y)/Fe3Al复合材料具有较单相ZrO2(3Y)更明显的R阻力行为。

Electrosynthesis and physicochemical properties ofα-PbO_2-CeO_2-TiO_2 composite electrodes

In order to investigate the effect of solid particles dopants on physicochemical properties of α-PbO2 electrodes, a-PbO2 composite electrodes doped with nano-TiO2 and nano-CeO2 particles were respectively prepared on A1/conductive coating electrodes in 4 mol/L NaOH solution with addition of PbO until saturation by anodic codeposition. The electrodeposition mechanism, morphology, composition and structure of the composite electrodes were characterized by cyclic voltarnmogram （CV）, SEM, EDAX and XRD. Results show that the doping solid particles can not change reaction mechanism of α-PbO2 electrode in alkaline or acid plating bath, but can improve deposition rate and reduce oxygen evolution potential. The doping solid particles can inhibit the growth of a-PbO2 unit cell and improve specific surface area. The diffraction peak intensity of a-PbO2-CeO2-TiO2 composite electrode is lower than that of pure a-PbO2 electrode. The electrocatalytic activity of a-PbO2-2.12%CEO2-3.71%TIO2 composite electrode is the best. The Guglielmi model for CeO2 and TiO2 codeposition with a-PbO2 is also pronosed.

Al_2O_3/Fe_3Al复合材料的制备及性能

利用热压烧结制备了致密的Al_2O_3/Fe_3Al复合材料。测试表明,该复合材料具有良好的力学性能,其抗弯强度和断裂韧性的最大值分别为832 MPa和7.96 MPa·m^1/2。对试样进行压痕实验,采用SEM对裂纹扩展方式进行观察,结果表明,在复合材料中存在着多种增韧机制,裂纹表现出复杂的扩展方式,这将在较大程度上吸收裂纹扩展能,从而使复合材料的断裂韧性得以提高。

耐水搪瓷涂层及其制备方法

本发明涉及搪瓷涂层,更具体地,涉及用于热水器的耐水搪瓷涂层。 搪瓷常遭受热水的腐蚀和溶解,这使其在诸如热水器等的应用中有困难。在热水器中,一旦保护金属基材的搪瓷涂层被一直溶解到基材,那么基材将很快发生腐蚀并被穿透,这时就必须更换热水器了。

Oxidative coupling of alcohols and amines to an imine over Mg-Al acid-base bifunctional oxide catalysts

A series of Mg‐Al mixed oxide catalysts are prepared and introduced as efficient irreducible catalysts for the oxidative coupling of alcohols and amines to imine.The structure and surface properties of Mg‐Al oxides are modulated by changing the Mg/Al ratios,calcination temperature and treatment with probe molecules.Detailed characterization,including X‐ray diffraction,27Al magic angle spinning nuclear magnetic resonance spectroscopy,N2‐adsorption,NH3‐temperature‐programmed desorption,CO2‐temperature‐programmed desorption and X‐ray photoelectron spectroscopy are carried out to determine the physicochemical properties of these catalysts.The Mg‐Al oxides with Mg/Al=3exhibit the highest activity in the reaction,which possess a large number of surface weak basic sites and a relatively small number of weak acidic sites.The role of the acidic and basic sites in the reaction process is systematically investigated,and are shown to serve as adsorption and activation sites for amines and alcohols,respectively.Under the synergistic effect of these acid‐base centers,the oxidative coupling process successfully occurs on the surface of Mg‐Al mixed oxides.Compared with the acidic sites,the weak basic sites play a more important role in the catalytic process.The acidic sites are the catalytic centers for the benzyl alcohol activation,which control the reaction rate of the oxidative coupling reaction.

Glycerol hydrogenolysis to n‐propanol over Zr‐Al composite oxide‐supported Pt catalysts

Zr‐Al mixed oxide supported Pt catalysts with different Zr/Al mole ratios（2.5%Pt/ZrxAl（1–x）Oy） were synthesized by an impregnation method and used for the selective hydrogenolysis of glycerol to n‐propanol in an autoclave reactor. The catalysts were fully characterized by X‐ray powder diffrac‐tion, Brunauer‐Emmett‐Teller surface area analysis, CO chemisorption, H2 temperature‐ pro‐grammed reduction, pyridine‐infrared spectroscopy, and NH3‐temperature‐programmed desorp‐tion. The results revealed that the Zr/Al ratio on the support significantly affected the size of the platinum particles and the properties of the acid sites on the catalysts. The catalytic performance was well correlated with the acidic properties of the catalyst; specifically, more acid sites contrib‐uted to the conversion and strong acid sites with a specific intensity contributed to the deep dehy‐dration of glycerol to form n‐propanol. Among the tested catalysts, 2.5 wt% Pt/Zr（0.7）Al（0.3）Oy exhibited excellent selectivity for n‐propanol with 81.2% glycerol conversion at 240 °C and 6.0 MPa H2 pres‐sure when 10% aqueous glycerol solution was used as the substrate. In addition, the effect of vari‐ous reaction parameters, such as H2 content, reaction temperature, reaction time, and number of experimental cycles were studied to determine the optimized reaction conditions and to evaluate the stability of the catalyst.

Effect of aluminium dust on secondary organic aerosol formation in m-xylene/NO_x photo-oxidation

As an important anthropogenic volatile organic compound(VOC), m-xylene has attracted numerous attentions due to its potential in secondary organic aerosol(SOA) formation. In this study, effects of aluminium dust seeds(boehmite and alumina) on SOA yield and aerosol size in m-xylene/NOx photo-oxidation were investigated in a 2 m3 smog chamber at 30°C and 50% relative humidity. Compared to the seed-free system, the presence of aluminium seeds resulted in an increase in the SOA yield, and also enhanced the O3 concentration in the chamber. The photolysis of O3 is a major source of OH radical, which is the most important oxidant of m-xylene. The increase in O3 concentration could result in the generation of more OH radicals, and finally contribute to the SOA formation. Seed particles influence the SOA size mainly by acting as condensation nuclei. Semi-volatile organic compounds(SVOCs) were condensed onto these nuclei, resulting in the increase in SOA size. However, when aluminium seeds with high concentrations were introduced into the system, SVOCs that had been condensed onto each particle were dispersed by these seeds, leading to the reduction in aerosol size.

Aluminum-based materials for advanced battery systems

There has been increasing interest in devel- oping micro/nanostructured aluminum-based materials for sustainable, dependable and high-efficiency electro- chemical energy storage. This review chiefly discusses the aluminum-based electrode materials mainly including A1203, AIF3, AIPO4, AI（OH）3, as well as the composites （carbons, silicons, metals and transition metal oxides） for lithium-ion batteries, the development of aluminum-ion batteries, and nickel-metal hydride alkaline secondary batteries, which summarizes the methodologies, related charge-storage mechanisms, the relationship between nanos- tructures and electrochemical properties found in recent years, latest research achievements and their potential ap- plications. In addition, we raise the relevant challenges in recently developed electrode materials and put forward new ideas for further development of micro/nanostructured aluminum-based materials in advanced battery systems.