Solution-phase synthesis of spherical zinc sulfide nanostructures

A facile solution-phase method has been developed to synthesize specially hollow and solid ZnS nanospheres. High-resolution TEM images on the nanospheres suggest their formation via the oriented aggregation of the primary ZnS nanocrystals. The morphology and size of the ZnS nanospheres can also be tuned easily by controlling the experimental conditions. These special spherical structures are very easily encapsulated within a uniform silica layer without any surface modification, suggesting potential applications in biochemistry and biodiagnostics.     

Highly anti-selective catalytic aldol reactions of amides with aldehydes

Barium phenoxide-catalyzed, highly anti-selective direct-type aldol reactions of amides with aldehydes have been developed. In the presence of a slight excess amount of an amide, the desired reactions proceeded smoothly under mild conditions, and a wide range of aromatic, heterocyclic, alpha,beta-unsaturated aldehydes were applicable to afford the desired adducts in high yields with high anti-selectivities. A catalytic, enantioselective reaction of an amide with an aldehyde using a chiral ligand is also described.     

Quantitative determination of stilbene oligomers in Jin Que-gen collected from different regions by a HPLC method

The objectives of this research were to determine simultaneously the contents of two stilbene tetramers, carasinol B (1) and kobophenol A (2), and one stilbene trimer, (+)-alpha-viniferin (3), in Jin Que-gen in different regions. A HPLC method has been developed for efficiently quantifying the three analytes in the plant. Using this method, different samples of Jin Que-gen were evaluated. The results showed that contents of the three analytes varied significantly among different samples, and the contents of the three analytes in commercial Jin Que-gen were markedly lower than those in the plants collected directly from growing regions. And for the three analytes, the longer the cultivation time, the higher the contents.     

A cationic tetrahedral chromophore for amplified DNA detection

The tetrahedral cationic chromophore, tetrakis [4-(9,9-bis(6′-(N,N,N-trimethylammonium)hexyl)-2-fluorenyl)phenyl]methane (1) shows better fluorescence resonance energy transfer (FRET) to the fluorescein (Fl) attached to the 5′-terminus of double-stranded DNA (dsDNA-Fl) as compared to the linear oligomers 2 and 3 and also provides efficient DNA hybridization detection.     

Anion‐controlled Syntheses and Crystal Structures of a Pair of Novel Azide‐bridged Copper(II) Complexes Constructed from 4‐Chloro‐2‐[(2‐dimethylaminoethylimino)methyl]phenol

A pair of novel azide‐bridged polynuclear copper(II) complexes, [CuL(μ_1,1‐N₃)]_n ( 1 ) and [Cu₄L₂(CH₃COO)₂(μ_1,1‐N₃)₄] ( 2 ) (L = 4‐chloro‐2‐[(2‐dimethylaminoethylimino)methyl]phenolate), have been obtained from the same Schiff base ligand and an identical synthetic procedure using anions of the metal salts as the only independent variable. Complex 1 was synthesized using copper(II) nitrate, while complex 2 was synthesized using the copper(II) acetate as the salt. Both of the complexes show novel supramolecular structures in their crystals as elucidated by X‐ray analyses. The polynuclear complex 1 contains [CuL(μ_1,1‐N₃)]_n units as the building blocks, crystallizes in the Pbca space group. The tetra‐nuclear complex 2 contains [Cu₄L₂(CH₃COO)₂(μ_1,1‐N₃)₄] units as the building blocks, crystallizes in the space group.     

Diamond anvil cell radial x-ray diffraction program at the National Synchrotron Light Source

During the past decade, the radial x-ray diffraction method using a diamond anvil cell (DAC) has been developed at the X17C beamline of the National Synchrotron Light Source. The detailed experimental procedure used with energy dispersive x-ray diffraction is described. The advantages and limitations of using the energy dispersive method for DAC radial diffraction studies are also discussed. The results for FeO at 135?GPa and other radial diffraction experiments performed at X17C are discussed in this report.     

Dimension Theory for Invariant Measures of Endomorphisms

We establish the exact dimensional property of an ergodic hyperbolic measure for a C ² non-invertible but non-degenerate endomorphism on a compact Riemannian manifold without boundary. Based on this, we give a new formula of Lyapunov dimension of ergodic measures and show it coincides with the dimension of hyperbolic ergodic measures in a setting of random endomorphisms. Our results extend several well known theorems of Barreira et al. (Ann Math 149:755–783, 1999) and Ledrappier and Young [Commun Math Phys 117(4):529–548, 1988] for diffeomorphisms to the case of endomorphisms.     

A Numerical Study of Jet Propulsion of an Oblate Jellyfish Using a Momentum Exchange-Based Immersed Boundary-Lattice Boltzmann Method

In present paper, the locomotion of an oblate jellyfish is numerically investigated by using a momentum exchange-based immersed boundary-Lattice Boltzmann method based on a dynamic model describing the oblate jellyfish. The present investigation is agreed fairly well with the previous experimental works. The Reynolds number and the mass density of the jellyfish are found to have significant effects on the locomotion of the oblate jellyfish. Increasing Reynolds number, the motion frequency of the jellyfish becomes slow due to the reduced work done for the pulsations, and decreases and increases before and after the mass density ratio of the jellyfish to the carried fluid is 0.1. The total work increases rapidly at small mass density ratios and slowly increases to a constant value at large mass density ratio. Moreover, as mass density ratio increases, the maximum forward velocity significantly reduces in the contraction stage, while the minimum forward velocity increases in the relaxation stage.     

Material transport in dip-pen nanolithography

Dip-pen na.nolithography （DPN） is a useful method for directly printing materials on surfaces with sub-50nm resolution. Because it, involves the physical transport of materials from a scanning probe tip to a surface and the subsequent chemical interaction of that material with the surface, there are many factors to consider when attempting to understand DPN. In this review, we overview the physical and chemical processes that are known to play a role in DPN, Through a detailed review of the literature, we classify inks into three general categories based on their transport properties, and highlight the myriad ways that. DPN can be used to perform chemistry at the tip of a scanning probe.