铅锡合金在硫酸溶液中生长阳极Pb(Ⅱ)氧化物膜的机理

用交流阻抗、开路电位衰退及线性电位扫描等方法在0.9V(vs.Hg/Hg₂SO₄)和4.5mol/LH₂SO₄溶液中,研究了铅及Pb-Sn合金电极上所生长的阳极氧化物膜.实验结果表明,阳极膜由溶解-沉淀机理控制生长,膜中微粒间为液膜,借助液膜作为离子通道可使膜中微粒发生阳极反应,锡有利于膜中PbO微粒表层阳极氧化为PbO^1+x(0相似文献   

HAsS2异构体结构与稳定性

在MP2/6-311++G(d,p)和QCISD(t)/6-311++G(3df,2p)(单点)水平下计算得到9个异构体和10个过渡态的HAsS₂体系势能面.异构体cis-HSAsS(E1)的能量最低,其次是trans-HSAsS(E2)、具有AsSS三元环的立体HAs(S)S(C_{s,E3)和HAs(S)S(C2v,E4)结构的异构体,能量分别比cis-HSAsS高1.46,60.78和93.63kJ/mol.根据体系的势能面,异构体E1,E2,E3和E4具有一定的动力学稳定性.AsH和S2第一步反应产物将会异构化为具有较高动力学稳定性的异构体E3,而SH和AsS第一步反应产物将会异构化为E1.计算结果与HNO2,HNS2,HPO2,HPS2和HAsO2等价电子相同的分子的势能面进行了比较.}     

漆酚铝高分子修饰碳糊电极用于溶出伏安法测定痕量银

漆酚铝树脂;漆酚铝高分子修饰碳糊电极用于溶出伏安法测定痕量银     

硼砂作稳定剂时胶体Sb2O5制备条件的优化

硼砂作稳定剂时胶体Sb2O5制备条件的优化     

A New Compound—Nanoline K2Ti8O15

In the product of carbon made from tar oil by plasma pyrogenation, some nanowires, whose diameter is 9~20 nm and whose length is 300 nm were found. The result of X-ray Energy Dispersed Spectrum (EDS) indicated that it is a new compound K2Ti8O15, which has never been reported before. Compared with the corresponding stoichiometry compound K2Ti8O15, it is a non-stoichiometry compound in which two oxygen atoms are absent. It is due to the fact that the intensive deoxidization occured in the experimental process and the valence of titalium is alterable. Its microstructure in detail by high revolution electromicroscopy (HREM) and X-ray diffraction were studied.     

用于红外变频的大尺寸AgGaS2晶体生长

在红外变频非线性光学应用中需要高光学质量大尺寸AgGaS2晶体元件.我们采用改进的Bridgman方法生长直径28mm、长度60～80mm的晶体棒.成功生长的关键是要采用C向籽晶.[001]籽晶生长的晶体中很少发现裂纹、聚片孪晶等宏观缺陷.在Ag2S共存下的热处理能有效地排除晶体中的异相沉淀,显著改善透明度.我们制备的Ⅰ型相位匹配8mm×10mm×16mm和5mm×5mm×15mm?AgGaS2晶体元件分别成功地应用于差频、和频激光实验.     

A Novel Class of Coherent Localized Structures for the Maccari System

By means of the Baecklund transformation, a quite general variable separation solution of the (2 1)-dimensional Maccari systems is derived. In addition to some types of the usual localized excitations such as dromion, lumps, ring soliton and oscillated dromion, breathers solution, fractal-dromion, fractal-lump and chaotic soliton structures can be easily constructed by selecting the arbitrary functions appropriately, a new novel class of coherent localized structures like peakon solution and compacton solution of this new system are found by selecting apfropriate functions.     

AB_2型储氢材料表面吸氢的光电子谱研究

AB2 型金属间化合物是新型的储氢材料 ,对 Zr V2 和 Zr Mn2 表面吸氢前后进行了紫外光电子谱( UPS)测量 .吸氢前后的差谱中 ,发现 Zr V2 吸氢后 ,结合能在 8e V左右出现较宽的吸附氢诱导的光电子谱峰 ;而 Zr Mn2 吸氢后 ,在 5e V左右有一个明显的峰 .实验结果表明 :氢在 Zr V2 表面的吸附所成M—H键的电子态的结合能比 Zr Mn2 表面上的要大 ,与 Zr V2 吸氢能力较强是一致的     

非饱和土的非线性固结模型和弹塑性固结模型及其应用

把作者最近提出的非饱和土的增量非线性本构模型及由作者改进的Alonso等人提出的非饱和土弹塑性模型引入陈正汉建立的非饱和土的固结理论,得到非饱和土的非线性固结模型和弹塑性固结模型,设计了有关程序,求解了地基在分级加载条件下的固结过程和塑性区的动态扩展,从而把非饱和土固结问题的研究推到了一个新水平。     

Long-time Convergence of Numerical Approximations for Semilinear Parabolic Equations （ Ⅱ ）

In this article we extend ours framework of long-time convergence for numeracal approximations of semihnear parabolic equations prorided in “Wu Haijun and Li Ronghua, Northeast. Math. J. , 16( 1 )(2000), 1-28“, to the Gauss-Ledendre full discretization. When apply the result to the CrankNicholson finiteelement full discretization of the Navier-Stokes equations, we can remore the grid-ratio restriction of “Heywood, J. G. and Rannaeher, R., SIAM J. Numer. Anal., 27(1990), 353-384“,and weaken the stability condition on the continuous solution.