乙烯催化二聚合成1－丁烯及其催化剂的研制

介绍了乙烯催化二聚合成１－丁烯的工艺特点、反应机理及影响该反应的因素。成功开发的ＤＣ－０１乙烯二聚催化剂，可代替同类型的进口催化剂ＬＣ２２５３。     

Cr2O7^2-／Cr^a＋和Ce^4＋／Ce^3＋电解液作媒质间接合成对甲氧基苯甲醛

在高剪切混合乳化机搅拌下，通过对Cr2O7^2-／Cr^a 和Ce^4 ／Ce^3 两种媒质间接合成对甲氧基苯甲醛槽外反应的研究，得到合成对甲氧基苯甲醛的优选条件分别为：原料配比n(Cr2O7^2-)：n(p-CH3O-C6H4-CH3)=1：6，反应温度80℃，反应时间10min，对甲氧基苯甲醛反应收率90．5％：原料配比n(Ce^4-)：n(p-CH3O-C6H4-CH3)=1：1，反应温度30℃，反应时间6min，对甲氧基苯甲醛反应收率97．1％。结果表明，Ce^4 ／Ce^3 做媒质产品时．空效率较低，这是Ce^4 ／Ce^3 媒质存在的本质缺陷：而Cr2O7^2-/Cr^3 做媒质产品时一空效率提高近2倍，显著地增加产品的产量，提高了经济效益。     

电解氧化处理难降解垃圾渗滤液研究

采用连续式电解槽对垃圾渗滤液进行电解催化处理研究。考察不同的极板间距、电流密度、电导率[Cl^-]浓度等对电解效果的影响。结果表明。在试验最佳条件下，电解催化法对中等CODCr浓度的垃圾渗滤液有较好的处理效果。极大降低了后续生化处理的负荷。对CODcr、NH3-N和色度的去除率分别能达到88．9％、97．3％和98．9％。为中试和工业设计应用提供了参考。     

用Faraday定律计算电解法溶解锡的质量

根据恒流电解原理和阴离子交换膜能防止阳离子透过的特性 ,建立了用电解法溶解锡样品的方法。通过选择合适的电解质和电解电流使电流效率为 1 0 0 % ,利用 Faraday定律 m=k It计算样品的溶解量。经计算 ,锡的电化摩尔质量 k=2 .2 1 4± 0 .0 0 1 g/( A· h)。当 0 .1和 0 .5 mol/LH2 SO4分别作阳极室和阴极室电解质、通 1 5 0 m A电流电解 0 .5 h时 ,称量阳极法得到样品的溶解量是 0 .1 663g,与理论计算值 0 .1 661 g一致     

钛材应用实例

介绍了钛材的使用原则及在氯碱行业中的应用实例，具体说明了钛材在电解氯气干燥系统及淡盐水处理系统中的各种结构形式的选择及应用，应用效果表明钛材的耐腐蚀性突出。指出钛材使用中应注意的问题。     

SiO2/TiO2 Composite Film for High Capacity and Excellent Cycling Stability in Lithium‐Ion Battery Anodes

In this study, partially crystalline anodic TiO₂ with SiO₂ well‐distributed througout the entire oxide film is prepared using plasma electrolytic oxidation (PEO) to obtain a high‐capacity anode with an excellent cycling stability for Li‐ion batteries. The micropore sizes in the anodic film become inhomogeneous as the SiO₂ content is increased from 0% to 25%. The X‐ray diffraction peaks show that the formed oxide contains the anatase and rutile phases of TiO₂. In addition, X‐ray photoelectron spectroscopy and energy‐dispersive X‐ray analyses confirm that TiO₂ contains amorphous SiO₂. Anodic oxides of the SiO₂/TiO₂ composite prepared by PEO in 0.2 m H₂SO₄ and 0.4 m Na₂SiO₃ electrolyte deliver the best performance in Li‐ion batteries, exhibiting a capacity of 240 µAh cm^?2 at a fairly high current density of 500 µA cm^–2. The composite film shows the typical Li–TiO₂ and Li–SiO₂ redox peaks in the cyclic voltammogram and a corresponding plateau in the galvanostatic charge/discharge curves. The as‐prepared SiO₂/TiO₂ composite anode shows at least twice the capacity of other types of binder‐free TiO₂ and TiO₂ composites and very stable cycling stability for more than 250 cycles despite the severe mechanical stress.     

电解锰渣盐酸浸取钙的动力学研究

以电解锰加工过程中产生的酸性废渣为原料,以盐酸为浸取剂,对电解锰渣中的钙进行浸取实验研究。结果表明：盐酸浓度为3 mol/L、液固体积质量比为6 mL/g、反应温度为80 ℃、反应时间为60 min的条件下,钙的浸取率为94.2%。酸浸过程的动力学分析表明,锰渣中钙的酸浸反应过程符合收缩核模型,受化学反应控制,其反应的表观活化能Ea为43.96 kJ/mol,反应级数为0.872 5。     

Enhancing the high cycle fatigue life of high strength aluminum alloys for aerospace applications

Hard anodized (HA) and micro arc oxidation (MAO) coatings of identical thickness were deposited on two different high strength aluminum (Al) alloys namely, 2024‐T3 and 7075‐T6. Further, as received Al alloys were also subjected to shot peening (SP) to induce subsurface compressive residual stresses followed by the MAO coating deposition (SP + MAO). The average velocity of particle‐in‐flight during the SP process was measured and utilized to calculate the kinetic energy of the peening particles. The bare and coated alloys were subjected to completely reversed stress (R = ?1) rotating beam high cycle fatigue tests at five different stress levels. In addition, the bare and coated alloys were also evaluated for their tensile properties, elemental composition, phase constituents, surface, and cross‐sectional morphologies including the surface roughness (Ra, Rz) and correlated the same with the corresponding fatigue behavior. Irrespective of substrate alloy composition and stress levels investigated, the duplex SP + MAO treatment resulted in significant fatigue life enhancement over and above the fatigue life of corresponding bare (not shot peened) Al alloy, while the hard anodized and plain MAO (both without prior shot peening) continue to exhibit significant fatigue debit. Driven by the compressive residual stresses present beneath the subsurface region of SP + MAO coating interface, fractured surface examination of SP + MAO coatings clearly highlights the crack‐branching associated multiple crack deflection as the predominant operative mechanism responsible for diminishing the crack growth rate and therefore enhance the fatigue life as compared with the near linear crack extension without significant deflections leading to relative premature failure of plain MAO coated alloys.     

Enhancement of coating characteristics via improved plasma electrolytic oxidation set-up

The plasma electrolytic oxidation process involves high-temperature operations and exposed to corrosive chemicals. Thus it requires stringent experimental set-up to produce uniform and high-quality coatings. This study proposes an enhancement to the current plasma electrolytic oxidation experimental set up to improve: 1) electrode holder; 2) cathode-anode electrodes, and 3) water-cooling system. In this paper, the focus is dedicated to the first two items. For the first item, the redesigned electrode holder is developed using 3-dimensional software. For the second item, results due to cathode via stainless container as well as carbon electrode are discussed. The performance of the new set-up plasma electrolytic oxidation is compared with the old one by analysing the microstructure and the mechanical properties of titanium dioxide coatings formed on a titanium aluminium vanadium alloy substrate using both set-ups. Surface morphology shows that the coating produced using the new set-up is thicker, denser and has lower porosity as compared to the coating deposited using the old set-up. The mechanical properties of hardness and adhesive strengths of the coating are also improved in the new set-up. Thus, the use of this set-up is recommended for improved coating performance to produce a uniform coating having enhanced mechanical performance.     

形貌可控及光学吸收性能可调的钙钛矿型SrTiO3纳米结构的原位生长

钙钛矿相SrTiO₃在太阳能电池、光催化、燃料电池, 超导等领域均有广泛应用, 这些应用均与其晶体质量、形貌、暴露晶面和光学吸收等特性息息相关。本文通过微弧氧化-水热两步法原位制备了两种典型形貌的SrTiO₃纳米晶。结果表明, 随着微弧氧化电解液锶源浓度的降低, SrTiO₃形貌从立方块状转变为超薄片状。进一步分析表明, 所得的SrTiO₃立方块和Sr_1-δTiO₃纳米片均为结晶质量良好的单晶体, 通过分析两种形貌样品的紫外-可见漫反射光谱, 发现Sr_1-δTiO₃纳米片相对于SrTiO₃立方块, 具有明显的尺寸效应诱导的光学吸收蓝移特性。最后, 本研究提出了SrTiO₃的原位生长及形貌演变机制。