Insertion theorems for maps to Banach lattices

We investigate semi-continuous maps from topological spaces into topological vector lattices. As an application, several insertion theorems with values in Banach lattices are given.     

Formation and manipulation of regular metallic nanoparticle arrays on bacterial surface layers: an advanced TEM study

The template-directed formation of regular nanoparticle arrays on two-dimensional crystalline protein layers after their treatment with metal salt complexes was studied by transmission electron microscopy. For these investigations, bacterial surface layers (S layers), recrystallized in vitro into sheets and tube-shaped protein crystals with typical dimensions in the micrometer range, were used as the template. As identified by electron holography and scanning force microscopy, the S-layer tubes form alternating double layers when deposited onto a solid substrate surface. Two distinct pathways for the metal particle formation at the templates have been found: the site-specific growth of metal clusters by chemical reduction of the metal salt complexes, and the electron-beam induced growth of nanoparticles in the transmission electron microscope. Both mechanisms lead to regular arrays with particle densities > 6×10¹¹ cm ^-2. Nanoparticle formation by electron exposure takes exclusively place in the flat-lying double-layered protein tubes, where a sufficient amount of metal complexes can be accumulated during sample preparation. Received 6 December 2000     

The Neighborhood Union of Essential Sets and Hamiltonicity of Graphs

Let G be a graph. An independent set Y in G is called an essential independent set (or essential set for simplicity) if there is {y1,y2} (?) Y such that dist (y1,y2) = 2. In this paper, we use the technique of the vertex insertion on l-connected (l = k or k + 1, k≥ 2) graphs to provide a unified proof for G to be hamiltonian, or hamiltonian-connected. The sufficient conditions are expressed     

Reaction mechanism and rate constants of the CH+CH4 reaction: a theoretical study

Ab initio and density functional calculations have been performed to elucidate the mechanism of CH radical insertion into methane. The results show that the reaction can be viewed to occur via two stages. On the first stage, the CH radical approaches methane without large structural changes to acquire proper positioning for the subsequent stage, where H-migration occurs from CH₄ to CH, along with a C–C bond formation. Where the first stage ends and the second begins, a tight transition state was located using the B3LYP/6-311G(d,p) and MP4(SDQ)/6-311++G(d,p) methods. Using a rigid rotor – harmonic oscillator approach within transition state theory, we show that at the MP5/6-311++G(d,p)//MP4(SDQ)/6-311++G(d,p) level the calculated rate constants are in a reasonably good agreement with experiment in a broad temperature range of 145–581 K. Even at low temperatures, the insertion reaction bottleneck is found about the location of the tight transition state, rather than at long separations between the CH and CH₄ reactants. In addition, high level CCSD(T)-F12/CBS calculations of the remainder of the C₂H₅ potential energy surface predict the CH+CH₄ reaction to proceed via the initial insertion step to the ethyl radical which then can emit a hydrogen atom to form highly exothermic C₂H₄+H products.     

Sulphur dioxide insertion into tin―carbon bonds: solvent effects and the nature of the transition state

Data describing the insertion of sulphur dioxide into the carbon―tin bond of a range of substituted phenyltrimethyltin compounds in methanol and benzene solvents have been reconsidered. The reaction in methanol is cleanly second order, but the reaction in benzene has both a second‐order and third‐order component, the latter ascribable to an initial equilibrium formation of a SO₂ complex with the phenyl ring followed by the insertion of a second SO₂ molecule into the carbon–tin bond. Molecular orbital calculations have identified the transition states (TS) and the favoured reaction pathways for the second‐order and third‐order reaction pathways in benzene. The effects of solvents on TS and enthalpies of reaction have also been examined. New insights into the types of TS involved in electrophilic substitution reactions are revealed. Copyright © 2013 John Wiley & Sons, Ltd.     

锂离子电池硅基负极材料嵌锂行为的第一性原理研究

采用基于密度泛函理论的第一性原理平面波赝势方法,计算不同数量的锂离子引起的硅材料晶体结构的变化以及在嵌锂过程中形成Li_xSi(x=1、2、2.4、4.4)合金相的形成能与电子结构.采用LST/QST方法计算过渡态,模拟合金体相中的锂离子迁移过程.计算结果表明,随着嵌锂数量的增加,硅晶胞的体积在不断增大;Li_xSi合金相的形成能为负值,表明在嵌锂过程中锂离子和硅原子可以自发形成这些合金相,其中Li₇Si₃合金最容易形成;随着嵌锂量的增加,锂离子在费米能级处s轨道提供的电子数逐渐增加,锂硅合金在费米能级处的电子数量呈增大趋势,表明锂硅合金的导电性越来越优;常温下Li₂Si体相中很难直接形成锂离子空位,但锂离子空位的迁移过程很容易发生.     

InSb的锂嵌入形成能第一原理计算

InSb材料在近来的锂离子电池负极材料研究中受到了重视.使用基于局域密度泛函理论的第一原理赝势法，计算了锂离子电池非碳类负极材料InSb各种锂嵌入情况时的形成能以及相应的电子结构.讨论了锂嵌入时的体积变化、能带结构、电子态密度以及电荷分布等性质.计算发现，闪锌矿结构的InSb材料，锂嵌入到主体材料的间隙位置时的形成能平均每个锂原子都在2.2eV左右. 关键词： InSb 锂嵌入形成能 电子结构 第一原理计算     

同步数字体系网管信息提取与插入系统的设计

现有的不同厂家的SDH设备网管信息不能实现互通,为了解决这一问题,提出了一种SDH网管信息提取和插入系统的软硬件设计方案,主要包括网管信息的提取和插入、HDLC数据的封装和拆封、利用主控制器和USB模块进行数据传输,从而实现网管信息的高速上传并在上位机实时显示和保存功能。最后对该系统进行了测试验证,结果表明该系统能分析不同的SDH设备网管信息,为网管信息互通提供了基础信息。     

杂双核(H)Rh-Cr配合物中乙烯插入RhI—H键反应的密度泛函研究

采用密度泛函理论B3LYP方法研究了配体和配位数对乙烯插入杂双核(CO)₄Cr(m-PH₂)₂RhH(L_n) (L＝CO或PH₃, n＝1或2)配合物中Rh—H键反应的影响. 计算结果表明, 六配位乙烯复合物中乙烯与铑之间轨道相互作用主要为乙烯到铑中心的s供体相互作用; 而五配位乙烯复合物中乙烯与铑中心间相互作用涉及乙烯到铑中心的s供体相互作用和铑到乙烯的p反馈作用. PH₃配体在热力学上不利于该反应. 处于氢配体对位的膦配体能加速乙烯插入反应. 乙烯插入的五配位反应途径占优势. Cr(CO)₄部分的引入降低了乙烯插入反应的活化能.