Cayley–Dickson Procedure, Relativistic Wave Equations and Supersymmetric Oscillators

The relativistic first-order wave equations for massive particles with spin 0,1,1/2 are formulated in terms of a factorization of the Klein–Fock equation by means of the algebra of octonions. An analogous method applied to Hamiltonian of the quantum isotropic oscillator leads to the natural generalization of the model. The class of supersymmetric oscillators with dimension N7 associated with te algebras of the Cayley–Dickson series is introduced.     

Synthesis of chitosan resin possessing a phenylarsonic acid moiety for collection/concentration of uranium and its determination by ICP-AES

A chitosan resin possessing a phenylarsonic acid moiety (phenylarsonic acid type chitosan resin) was developed for the collection and concentration of trace uranium prior to inductively coupled plasma (ICP) atomic emission spectrometry (AES) measurement. The adsorption behavior of 52 elements was systematically examined by packing it in a minicolumn and measuring the elements in the effluent by ICP mass spectrometry. The resin could adsorb several cationic species by a chelating mechanism, and several oxo acids, such as Ti(IV), V(V), Mo(VI), and W(VI), by an anion-exchange mechanism and/or a chelating mechanism. Especially, U(VI) could be adsorbed almost 100% over a wide pH region from pH 4 to 8. Uranium adsorbed was easily eluted with 1 M nitric acid (10 mL), and the 25-fold preconcentration of uranium was achieved by using a proposed column procedure, which could be applied to the determination of trace uranium in seawater by ICP-AES. The limit of detection was 0.1 ng mL⁻¹ for measurement by ICP-AES coupled with 25-fold column preconcentration.     

One-pot enyne metathesis/Diels-Alder reaction for the construction of highly functionalized novel polycyclic aza-compounds

Various tricyclic dienes were synthesized via enyne metathesis using the first generation Grubbs catalyst. The enyne metathesis proceeded smoothly in refluxing CH₂Cl₂ with a low catalyst loading (3.0 mol %), giving good yields (72-89%) of the tricyclic products 6 and 16. The resulting 1,3-dienes are suitable precursors of polycyclic structures via a Diels-Alder process. One-pot RCM/Diels-Alder reactions of the enyne products with dienophiles proceeded smoothly to afford polycyclic compounds as a single cycloadduct. The structures of the Diels-Alder adducts were determined by ¹H NMR spectra and X-ray analysis. The cycloadducts were formed via the approach of the dienophiles towards the diene in endo mode.     

Reply to “Comment on Aromatic‐Backbone Interactions in Model α‐Helical Peptides”

In response to Van Mourik's comments on our paper (J Comput Chem 2007, 28, 1208.) we present an extended version of our rotation method. We also prove that intramolecular interaction energies as well the basis set superposition errors calculated with our rotation method are comparable with those obtained by the counterpoise method of Boys and Bernardi (Mol Phys 1970, 19, 533). In intramolecular interaction energy calculations, if the interacting groups are in proximity, our rotation method is recommended to avoid artificial interactions, which can be induced by fragmentation. © 2007 Wiley Periodicals, Inc.J Comput Chem, 2008     

A green and novel procedure for the preparation of ionic liquid

A green and novel procedure is described for the preparation of a series of ionic liquid containing alkylimidazolium-based or N-alkylpyridinium-based cations and hexafluorophosphate-based or tetrafluoroborate-based anions in one-pot solvent-free conditions to give excellent yields with shortened time.     

量子动力学的约化与自相似(英文)

推广少体问题中的 AGS约化理论 ,证明量子动力学在不同层次具有相同形式 ,称为量子动力学的自相似.By a generalized version of AGS reduction procedure we show that the forms of quantum dynamics at different strata are the same. This is the self similarity of quantum dynamics.     

复合材料三角形网格加筋圆锥壳体位移型稳定性方程及其总体稳定性分析

本文采用Donnell型扁壳理论,首先利用最小势能原理和广义平均筋条刚度法推导出用位移分量表示的复合材料三角形网格加筋叠层圆锥壳体的稳定性方程,考虑了蒙皮最一般的拉弯与拉扭耦合关系和加筋筋条的偏心效应,并讨论了该方程的基本性质.根据外压实验观察结果,通过选取适当的位移分量表达式,并运用Galerkin法分析了在均布外压作用下复合材料三角形网格加筋叠层圆锥壳体总体稳定性,得到了临界载荷的解析表达式,并对某一类C/E复合材料三角形内网格加筋圆锥壳体的临界外压进行了计算,所得理论值与实验结果很好地吻合.最后,讨论了有关参数对临界载荷的影响.本文所建立的新方程和所得结果对于航空航天结构非常有用.     

气敏半导体材料Cd2Sb2O6.8的制备及其性能研究

采用化学共沉淀法,在较低温度(750℃)下制备了具有缺陷烧绿石结构的复合氧化物Cd₂Sb₂O_6.8的纯相超微粉;研究了制备条件对物相、结构和气敏性能的影响,并对其反应过程机理进行了探讨,气敏性能测试结果表明,纯相Cd₂Sb₂O_6.8气敏元件对乙炔气体有较高的灵敏度和较好的选择性.     

三原子分子振转激发态的理论研究

三原子分子振转激发态的理论研究谢代前,鄢国森,田安民（四川大学化学系,成都,６１００６４）关键词振转激发态,三原子分子,变分法能级较高的振转激发态通常包含大振幅运动,其波函数分布于很广的势能面区域内,传统的正则模理论已不适合于解决这类问题．近年来,Ｈ...