Pattern and feature designed growth of ZnO nanowire arrays for vertical devices

An approach is demonstrated for growing aligned ZnO nanowire/nanorod arrays following a predesigned pattern and feature with controlled site, shape, distribution, and orientation. The technique relies on an integration of atomic force microscopy (AFM) nanomachining with catalytically activated vapor-liquid-solid (VLS) growth. The pattern and growth locations are defined by the catalyst distribution created by AFM, and the orientation is determined by the epitaxial growth on a single-crystal substrate. The technique opens a variety of possibilities of using nanowire arrays as sensor arrays, piezoelectric antenna arrays, nanolasers, photonic band gap crystal, biosensors, and field emitters with controlled density, location, shape, and distribution according to a designed pattern and feature.     

Determination of Ba, Fe, Sr, and Zr in silicate materials with ED-XRF using241Am excitation source

The possibilities of ED-XRF with²⁴¹Am excitation source are evaluated in the analysis of geological materials: rocks, clays, soils, and sediments. The calibration curves are made using different SRM's. Data from the analysis of various SRM's are presented.     

Evolution of quasi-stationary states of an electron in an open spherical quantum dot

Physics of the Solid State - A theory of the evolution of spectral parameters of quasi-stationary states of an electron in an open spherical quantum dot is proposed in terms of the effective-mass...     

A mononuclear manganese(III) complex of an asymmetric macrocyclic ligand with a ring contraction [MnHL2(ClO4)](ClO4) · 2.5H2O

The template reaction of sodium 2,6-diformyl-4-chlorophenolate and N,N-bis(2-aminoethyl)–hydroxyethylamine followed by in situ transmetallation of Mn(ClO₄)₂ results in a mononuclear manganese(III) complex of one 21-membered asymmetric 2:2 Schiff base macrocycle, in which a hydroxyethyl group of the amine has been eliminated and ring contraction at one chamber of the macrocycle has occurred to form an imidazolidine ring. An X-ray study indicates that the geometry about the manganese(III) ion is distorted octahedral. The electrochemical behavior of this complex in MeCN has been studied by cyclic voltammetry.     

Synthesis and nonlinear optical properties of novel Y‐type polyurethane containing tricyanovinylthiazole with enhanced thermal stability of second harmonic generation

A novel Y‐type poly[iminocarbonyloxyethyl‐5‐methyl‐4‐{2‐thiazolylazo‐4‐(1,2,2‐tricyanovinyl)}resorcinoxyethyloxycarbonylimino‐(3,3′‐dimethoxy‐4,4′‐biphenylene)] 4 containing 5‐methyl‐4‐{5‐(1,2,2‐tricyanovinyl)‐2‐thiazolylazo}resorcinoxy groups as nonlinear optical (NLO) chromophores, which constitute part of the polymer backbone, was prepared and characterized. Polyurethane 4 is soluble in common organic solvents such as acetone and N,N‐dimethylformamide. It showed a thermal stability up to 250 °C in thermogravimetric analysis thermogram and the glass‐transition temperature (T_g) obtained from differential scanning calorimetry thermogram was around 118 °C. The second harmonic generation coefficient (d₃₃) of poled polymer films at 1560 nm fundamental wavelength was around 8.43 × 10^?9 esu. The dipole alignment exhibited a thermal stability even at 12 °C higher than T_g, and there was no SHG decay below 130 °C due to the partial main‐chain character of the polymer structure, which is acceptable for NLO device applications. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1166–1172, 2010     

Labdane Diterpenes and Flavonoids from Leonurus japonicus

Chemical investigation of the aerial part of Leonurus japonicus led to the isolation and characterization of a new labdane‐type diterpene, named 3α‐acetoxy‐15‐O‐methylleopersin C ( 3 ), and a new acylated rutin derivative, named 2′′′‐syringylrutin ( 9 ), along with seven known compounds, including a labdane‐type diterpene and six flavonoids. The structures of the new compounds were established by spectroscopic methods.     

柞蚕蛹中营养成分的分析

1引言柞蚕蛹又名茧蛹，为天蚕蛾科动物柞蚕（antheraeaepemyigeurin-meneville）新鲜或干燥的蛹。在我国分布很广，民间多把它当做一种高营养的风味佳品。柞蚕蛹亦有一定的药用价值，最早收载于《东北动物药》中，具有生津止渴、消食理气，镇痛等功效。为进一步开发利用柞蚕蛹的药用及营养价值，我们对其营养成分进行了分析，并对其营养价值进行了初步的评价。2材料与方法2．1供试样品柞蚕蛹从市场购得，经廊坊市药检所鉴定为天蚕蛾科动物柞蚕的新鲜蛹。2．2测试方法与仪器（1）脂肪酸测定的前处理法将鲜蛹用水煮，取浆，阴干，获得荣干粉。…     

类硅烯H_2SiLiF二聚反应的理论研究

从理论上研究了类硅烯H2SiLiF的三元环构型为反应物的二聚反应2H2SiLiF→H2SiSiH2+2LiF。在MP2/6-31G(d)和QCISD(T)/6-31G(d)水平下的计算结果表明,H2SiLiF的二聚反应经过两个阶段:阶段I,先形成过渡态TS1,经过中间体Int,形成一个四元环的中间产物Pro1,同时消去一个LiF;阶段Ⅱ,Pro1继续反应形成过渡态TS2,进而解离生成产物H2SiSiH2和一个LiF。从能量上看,反应易停留在中间产物阶段。本文对反应物、过渡态以及产物的结构、稳定性等方面进行了讨论,很好解释了实验结果。