铈对锂铝合金阳极充放电性能的影响

研究了铈对锂铝合金阳极充放电性能的影响。在锂铝合金阳极中添加 0 5%～ 1 5% (质量分数 )铈 ,可增大电池的放电容量和电压 ,改善锂铝合金阳极的表面形貌。添加铈的多孔锂铝合金阳极具有理想的充放电性能。     

铈对锂在铝电极上电极过程的影响

利用循环钛安法和计时电流法研究了在铈在铝电极上的电极过程和铈对锂在铝电极上电有过程的影响。铈不仅改善了锂铝合金的电化学性能，而且改进了铝基体材料的物理性能。为制备锂铝合金阳极提供了依据。     

铈、锂盐对铝阳极氧化膜的协同封闭作用

研究了铈、锂盐在铝阳极氧化膜封闭处理中的协同作用.场发射扫描电镜和X射线衍射谱对铈、锂盐协同封闭前后铝阳极氧化膜形貌和结构的研究结果表明，封闭后膜表面的孔洞消失，封闭产物分布均匀，封闭后膜仍然以非晶态形式存在.根据X射线光电子能谱的结果，封闭后的膜主要由含结晶水的Al2O3及铈、锂的混合氢氧化物组成，同时膜中还含有及封闭溶液组分中的一些阴离子.电化学阻抗谱的研究结果表明铈、锂盐协同封闭能够显著提高膜的耐蚀性能.在实验结果基础上，初步认为铈、锂盐封闭是通过生成结构紧密的封闭产物填充、覆盖膜孔，从而显著提高铝阳极氧化膜的耐蚀性能.     

LiCl—KCl熔盐中锂在铝电极上的电极过程

采用线性扫描伏安法和电位阶跃法，研究了锂离子在铝电极上的电极过程机理，结果表明锂离子在铝电极上沉积形成α－固熔体时，电极过程受锂原子向铝电极中的扩散速度控制，当形成β－锂铝合地，存在成核极化现象，成核过程为瞬间成核过程，初期电极过程受形成β－锂铝合金的速度控制，一定时间后受锂原子通过β－锂铝合金层的扩散速度控制，β－锂铝合金阳极有限限充电电压和极限电流。     

由含铝金属有机骨架材料制备的多孔碳在锂硫电池中的应用

采用水热法制备了一种含铝金属有机骨架材料, 其在高温下发生炭化得到多孔碳, 最后与硫复合制得锂硫电池正极材料. XRD图谱显示在高温炭化时多孔碳样品出现了部分石墨化. N₂等温吸附-脱附测试分析显示合成的多孔碳材料含有微孔和介孔结构. 对不同载硫量的锂硫电池进行了充放电性能测试, 结果显示S质量分数为46.3%的样品在0.01 C倍率下首次放电容量达到1272 mA·h/g; 在0.1 C倍率下首次放电容量为934 mA·h/g, 循环性能良好.     

杂质及铈作用下铝锂合金的应力集中敏感性

建立了评价铝锂合金应力集中敏感性的缺口敏感因子,通过测定薄板法拉伸性能,求出了不同元素及杂质含量的铝锂合金缺口敏感因子,Fe,Si,Na,K杂质均明显地增加2090及8090合金的应力集中敏感性,铈能够在一定程度上降低具有较高强度水平的合金应力集中敏感性,但在塑性水平较高的1420合金中,铈添加量超过一定限度后,反而会显著提高材料的应力集中敏感性,相对于普通铝合金,铝锂合金的应力集中敏感性一般处于较高水平,这个问题在此对类合金的实际研究中应给予充分注意。     

稀土元素对2090铝锂合金疲劳短裂纹门槛值的影响

测出２０９０铝锂合金的ΔＫｔｈ～Δａｔｈ，ΔＫｃｌ．ｔｈ～Δａｔｈ等曲线，并选用７０７５铝合金作对比试验，定量地评定了该合金疲劳短裂纹扩展抗力，探明了基短裂纹效应强的本质原因。同时，研究了稀土元素铈的影响。结果表明，在２０９０铝锂合金中添加微量铈，可较大提出其Δｋｉ，也有益于其ΔＫＣｌ．ｔｈ，因此，不仅消除了该合金疲劳短裂纹扩展抗力低的本质因素，还使其疲劳长裂纹扩展抗力进一步提高。     

铝及铝镁合金中铈的合金化量及其显微分布

在工业纯铝及铝镁合金制品中加入少量稀土合金可以提高其机械性能与抗腐蚀性能,但稀土的作用机理则不甚清楚。本文用放射性测量方法测定了铝及铝镁合金中铈之合金化量,用电子探针及涂层法自射线照相研究了铈在其中的分布。 实验分别将工业纯铝(含Si 0.15％、Fe 0.14％)与铝镁合金(含Si 0.14％、Fe 0.32％、     

Cu-Ce/ZSM-5催化剂的TPR及动力学研究

由Ｃｕ、Ｃｅ的硝酸盐（氧化物）用浸渍法、分散法制备了系列Ｃｕ－Ｃｅ／ＺＳＭ－５催化剂。对这些催化剂进行了ＴＰＲ、ＩＲ表征及动力学研究。考察了铜含量、铈含量及不同铈源对催化剂还原性能的影响。结果表明：１．不含铈的Ｃｕ／ＺＳＭ－５催化剂的ＴＰＲ谱,铜离子的两个还原峰峰温及峰面积随铜含量增加而增加;２．铈源为ＣｅＯ２,铈含量增大,使Ｃｕ－Ｃｅ／ＺＳＭ－５催化剂的铜离子还原峰峰温略为降低;铈源为Ｃｅ（ＮＯ     

含镓、锡的铝合金在碱性溶液中的阳极行为

铝的电极电位负,为一1．66V（VS．SHE）,电化当量高（298Ah／g）是一种理想的阳板材料．但是由于铝在空气和水中表面形成一层致密的氧化膜,使其在中性溶液中处于钝化状态．而在酸性或碱性溶液中铝表面氧化膜就会被溶解破坏,与水直接反应,腐蚀中途难以中止．这一直是影响铝作为阳板材料应用和深入研究的障碍,特别是对铝阳极活化溶解机理的研究进展缓慢．虽然目前人们在铝中添加Ga、In、11、Zn、Sn、Mg、Hg等元素,研制出各种铝合金阳极,提高了铝阳极活化性能,但是这些研究本质上仍属于经验性的．到1983年Despic等人提出了“场…     

Reductive Deoxygenation of Carbonyl to Methylene by LiAlH4／InBr3

The reductive deoxygenation of aldehydes and ketones into the corresponding alkanes is accomplished by LiAlH4 in the presence of Lewis acid InBr3. It provides a convenient method to complete the transformation from carbonyl compounds to alkanes.     

LiAlH4: From Stoichiometric Reduction to Imine Hydrogenation Catalysis

Imine‐to‐amine conversion with catalytic instead of stoichiometric quantities of LiAlH₄ is demonstrated (85 °C, catalyst loading≥2.5 mol %, pressure≥1 bar). The effects of temperature, pressure, solvent, and catalyst modifications, as well as the substrate scope are discussed. Experimental investigations and preliminary DFT calculations suggest that the catalytically active species is generated in situ: LiAlH₄+Ph(H)C=NtBu→LiAlH₂[N(tBu)CH₂Ph]₂. A cooperative mechanism in which Li and Al both play a prominent role is proposed.     

Synthese und Kristallstruktur von LiAl[(P2O6)2]

Synthesis and Crystal Structure Determination of LiAl[(P₂O₆)₂] Single crystals of previously unknown LiAl[(P₂O₆)₂] have been obtained by reaction of Li₂CO₃, Al₂O₃ and H₃PO₄ (1:1:16) at 350°C. The title compound crystallizes in Pbcn (a = 1 244.54(1), b = 823.40(1), c = 892.46(1) pm; Z = 4). The least-squares refinement (with anisotropic temperature factors) was performed using 766 observed reflections yielding R = 0.029 and R(w) = 0.075. Four anion chains are running parallel to the shortest axis in the unit cell, the period of identity amounting to four. Aluminium is surrounded by an almost regular octahedron, lithium by a distorted tetrahedron of oxygen.     

Active corrosion protection of various aluminium alloys by lithium-leaching coatings

This study presents the active protective properties of lithium-leaching coatings for a range of aluminium alloys. Coatings with and without lithium carbonate as leachable inhibitor were applied on the aluminium alloys, artificially damaged and exposed to the neutral salt spray. A combined approach of scanning electron microscopy and electrochemical measurements revealed that the lithium carbonate leaching coating provided effective corrosion inhibition on AA2024, AA7075, AA5083, and AA6014 by the formation of a protective layer in the defect area and preventing local corrosion processes despite the different intrinsic electrochemical activity of the alloys.     

SYNTHESIS OF SELENOL ESTERS USING ACYL HALIDES AND A NOVEL SELENATING REAGENT,LiAlHSeH

Several selenol esters were synthesized by the reaction of acyl chlorides with LiAlHSeH then with alkyl halides in moderate to good yields.     

Reductive Deoxygenation of Carbonyl to Methylene

The reductive deoxygenation of aldehydes and ketones into the corresponding alkanes is accomplished by LiAlH4, in the presence of Lewis acid InBr3. It provides a convenient method to complete the transformation from carbonyl compounds to alkanes.     

Synthesis of poly(propylene imine) dendrimers via homogeneous reduction process using lithium aluminium hydride: Bioconjugation with folic acid and doxorubicin release kinetics

The heterogeneous reduction process for synthesis of poly(propylene imine) (PPI) dendrimer has been replaced by a novel and homogeneous process. Accordingly, to prepare half generations, acrylonitrile was added to amine groups via Michael addition reaction. Then, nitrile groups were reduced via homogeneous hydrogenation using lithium aluminium hydride to synthesize fifth‐generation PPI dendrimers with ethylenediamine core. Also, peripheral primary amine groups were conjugated with folic acid (FA). Fourier transform infrared and ¹³C NMR spectroscopies and gel permeation chromatograph y were used to prove the synthesis of the various structures. Finally fifth‐generation and FA‐conjugated fifth‐generation PPI dendrimers were loaded with doxorubicin and exposed to environments with different pH values to examine the release properties of the structures. Also, drug release kinetics was investigated by fitting experimental data with various release models. The synthesized dendritic structures showed Higuchi model release behaviour due to better solubility of drug in release media with respect to dendrimer cavities.