类He离子基态的Hartree-Fock有限元计算

FEM直至七十年代中期才应用于原子分子问题。已有工作虽不多,却说明FEM对一维和二维问题是有效的,但应用于n(≥3)电子原子问題至少在目前是不现实的。我们提出一种FEM与HF方法相结合的方法(HFFEM),在DPS8机上计算了类He离子的基态能量与平均值<rⁿ>,能量计算值与实验值的误差在0.3%~0.03%之间。这种HFFEM可推广应用于各种原子与分子问题。     

银纳米颗粒表面覆盖度对非晶硅薄膜光吸收特性的影响

本文采用磁控溅射系统在非晶硅薄膜的表面沉积不同覆盖度的银纳米颗粒,并研究纳米颗粒的表面覆盖度对非晶硅薄膜光吸收特性的影响.结果表明随着纳米颗粒表面覆盖度的增加,薄膜的晶格结构并不受影响.但是,随着表面覆盖度的增加,薄膜在近红外区域内对光的吸收范围却发生了明显变化.当纳米颗粒的表面覆盖度达到8;时,薄膜在近红外区域内对光的吸收范围达到了最大.这主要是由于纳米颗粒的局域表面等离子体增强了光吸收.     

Synthesis and Crystal Structure of 5,17-Diformyl-11,23-di（tert-butyl）25,26,27,28-tetrapropoxy-calix[4]arene

The title compound 5,17-diformyl-11,23-di（tert-butyl）-25,26,27,28-tetrapropoxycalix[4]arene has been synthesized by selective formylation of 5,11,17,23-tetra（tert-butyl）25,26,27,28-tetrahydroxycalix[4]arene in three steps and characterized by1H NMR and X-ray single-crystal diffraction.The crystal belongs to the monoclinic system,space group C2/c with a = 25.760（3）,b = 10.9952（10）,c = 18.630（2）,β = 119.985（4）°,V = 4570.4（9）3,Z = 4,Dc = 1.106 g/cm3,Mr = 761.01,F（000） = 1648,μ = 0.071 mm-1,MoKa radiation（λ = 0.71073）,R = 0.0710 and wR = 0.2411 for 3234 observed reflections with I 2σ（I）.X-ray analysis reveals that the title compound adopts a pinched cone conformation which leads to an open cavity.Intermolecular C–H O weak interactions link the molecules along the bc plane,which are effective in the stabilization of the crystal structure.