The uniform modulus of continuity of iterated Brownian motion

LetX be a Brownian motion defined on the line (withX(0)=0) and letY be an independent Brownian motion defined on the nonnegative real numbers. For allt0, we define theiterated Brownian motion (IBM),Z, by setting . In this paper we determine the exact uniform modulus of continuity of the process Z.Research supported by NSF grant DMS-9122242.     

Low Temperature Preparation of 3D Solid and Hollow ZnS Nanosphere Self-Assembled from Nanoparticles by Varying Sulfur Source

In this work, we report a facile hydrothermal method for the preparation of three dimensional hollow ZnS nanostructures, using Zinc bis(salicyle aldehitato), Zn(Sal)₂, thioacetamide (TAA) and thioglycolic acid (TGA) as Zn²⁺, sulfur source and capping agent, respectively. The ZnS solid and hollow sphere was produced from the self-assembly of nanoparticles with diameters of 11 ± 2 nm with TGA and TGA, TAA, respectively. Furthermore, with changing zinc precursor from Zn(Sal)₂ to zinc acetate [Zn(OAC)₂], ZnS nanorods were obtained. The products were characterized by XRD, SEM, TEM, selected area electron diffraction, and FT-IR spectra. The influence of surfactant (Polyethylene glycol) on the morphology of the products was also investigated. Possible formation mechanism and optical properties of these architectures were also reported.     

Electrospray ionization tandem mass spectrometric characteristics and fragmentation mechanisms of distamycin analogues

The electrospray ionization tandem mass spectrometric (ESI-MS/MS) characteristics and fragmentation mechanisms of eight distamycin analogues containing N-methylpyrrole and N-methylimidazole were investigated. The members of two isomeric groups of distamycin analogues with the same elemental composition can be distinguished by MS/MS spectra of protonated molecules and of significant fragment ions.     

Systematical Synthesis of Distamycin Analogues and Their Interaction with Herring Sperm DNA

A simple procedure for the systematical synthesis of eight distamycin analogues containing N‐methylpyrrole (Py) and N‐methylimidazole (Im) has been developed by a chloroform reaction and DCC coupling reaction without amino protection and deprotection, and the interaction of the analogues with Herring Sperm DNA was investigated by fluorescence spectroscopy.     

Synthesis,structural characterization and alcohol oxidation activity of a new mononuclear manganese(II) complex

A manganese(II) complex of 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tptz) has been synthesized and characterized by single-crystal X-ray diffraction, elemental analyses, IR, and UV–Vis spectroscopic techniques. Oxidation of alcohols to their corresponding aldehydes and ketones was conducted by this catalyst using oxone (2KHSO₅·KHSO₄·K₂SO₄) as an oxidant under biphasic reaction conditions (CH₂Cl₂/H₂O) and tetra-n-butylammonium bromide as phase transfer agent under air at room temperature. Easy preparation, mild reaction conditions, high yields of the products, short reaction times, no further oxidation to the corresponding carboxylic acids, high selectivity and inexpensive reagents make this catalytic system a useful oxidation method for aliphatic and benzylic alcohols.     

Nano-sized Cu6Sn5 alloy prepared by a co-precipitation reductive route

Nano-sized Cu₆Sn₅ alloy powders were prepared by a co-precipitation reductive route using a hydrothermal method at 80 °C. The nano-size and morphology of the synthesized Cu₆Sn₅ alloy powders were evaluated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The obtained morphologies, chemical compositions are comparatively discussed. A variety of synthesis parameters, such as time, capping agent and sort of reductant, has an effect on the morphology of the obtained materials, and will be particularly highlighted.     

Dynamic Response of a Grid-Stiffened Composite Cylindrical Shell Reinforced with Carbon Nanotubes to a Radial Impulse Load

Mechanics of Composite Materials - Equilibrium equations of a rib grid-stiffened composite cylindrical shell reinforced with carbon nanotubes (CNTs) are derived based on the first-order shear...     

Synthesis and Crystal Structure of Bis (Tetrabutylammonium)(4,4′-Azodi(phenylcyanamide)) Salt · [(<Emphasis Type="Italic">n</Emphasis>-Bu)<Subscript>4</Subscript>N]<Subscript>2</Subscript>[Azodicyd<Superscript>2−</Superscript>] · H<Subscript>2</Subscript>O

Abstract The chemical preparation and crystal structure for a 4,4′-azodi(phenylcyanamide) salt) in the solid state are reported. This compound crystallizes in the triclinic space group P with the following unit cell parameters: a = 9.759(3) ?, b = 11.237(4) ?, c = 11.919(4) ?, α = 95.54(3)°, β = 98.50(3)°, γ = 109.39(2)°, Z = 1 and V = 1204.4(7) ?³. The 4,4′-azodi(phenylcyanamide) dianion, azodicyd²⁻, is approximately planar, with the cyanamide groups (–N=C=N) in an anti conformation relative to each other and the azo group (–N=N–) adopting the more thermodynamically stable trans conformation. The crystal X-ray analysis shows that there are one azo molecule cation, two tetrabutylammonium cations and one water molecule in unit cell. Intermolecular O–H···N hydrogen bonds may be effective in the stabilization of the crystal structure of this compound and to form linear chain structure in the packing. Index Abstract Synthesis and crystal structure of Bis (Tetrabutylammonium)(4,4′-Azodi(phenylcyanamide)) salt . [(n-Bu)4N]2[Azodicyd^2-] · H₂O Davar M. Boghaei ^1*, Fatemeh Behzadian-Asl ¹ and Hamid Reza Khavasi^{2 1} Department of Chemistry, Sharif University of Technology, P.O. Box 11155-9616, Tehran, Iran ² Department of Chemistry, Shahid Beheshti University, Evin, Tehran 1983963113, Iran Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.