Synthesis of polybutadienes with controllable microstructure by a novel binary Nd(3-NBSO3)3/alkylaluminum catalyst system

The polymerization of 1,3-butadiene was examined by using a novel halogen-free neodymium m-nitrobenzenesulfonate(Nd(3-NBSO3)3·donors)/alkylaluminum binary catalyst system. The catalyst showed fairly high activity and controllable selectivity. The microstructure of the resultant polymer was adjustable by variation of electron donor and/or the alkylaluminum. 13C-NMR and thermal analysis demonstrate that the produced polybutadienes have stereo-block chain structures of cis-1,4 and trans-1,4 segments with adjustable Tm and Tc. The neodymium sulfonate-based catalyst is believed to be significant in regulating the chain structure of polydienes and in exploring 1,3-diene polymerization mechanism.     

UV‐Responsive Supramolecular Vesicles with Double Hydrophobic Chains

In order to improve the stability of polymeric vesicles, supramolecular vesicles are developed via self‐assembly of the inclusion of γ‐cyclodextrin (γ‐CD) and 1‐pyrenemethyl palmitate (Py‐pal). The inclusion has one hydrophilic head and double hydrophobic tails, which looks like the phospholipid. From the transmission electron microscopy (TEM) image, it can be observed that the average diameter of supramolecular vesicles is approximately 55 nm and there is a huge cavity in supramolecular vesicles. Due to the photo‐breakable ester of Py‐pal, supramolecular vesicles are broken under UV irradiation. Supramolecular vesicles are used as UV‐responsive drug carriers to release the hydrophilic drug such as doxorubicin hydrochloride (DOX•HCl).

     

On Galvin’s theorem for compact Hausdorff right-topological semigroups with dense topological centers

We generalize an important theorem of Fred Galvin from the Stone-Cˇech compactification βT of any discrete semigroup T to any compact Hausdorff right-topological semigroup with a dense topological center;and then apply it to Ellis' semigroups to prove that a point is distal if and only if it is IP*-recurrent, for any semiflow(T, X) with arbitrary compact Hausdorff phase space X not necessarily metrizable and with arbitrary phase semigroup T not necessarily cancelable.     

A new phenomenon of acoustic streaming

This paper describes a new phenomenon of acoustic streaming which takes place when a Helmholtz resonator is excited by an inside sound source with resonant frequency, and takes the form of a strong turbulent jet. The flow visualizations, hot wire and LDV measurements are combined to investigate the process of acoustic streaming. It is found that this kind of acoustic streaming results from the contribution of Reynolds stress.     

单光束错位云纹干涉法测板的斜率和曲率

本文提出一种用高密度位相型闪耀光栅测取板的曲率和斜率的单光束错位云纹干涉法,由于这一方法具有高灵敏度。大量程和高反差的优点。可有效地用来求解板的弯曲问题。文中还给出了周边固定圆板和带缺口的方板两个应用实例。     

Recent advances in liposomal nanohybrid cerasomes as promising drug nanocarriers

Liposomes have been extensively investigated as possible carriers for diagnostic or therapeutic agents due to their unique properties. However, liposomes still have not attained their full potential as drug and gene delivery vehicles because of their insufficient morphological stability. Recently, a super-stable and freestanding hybrid liposomal cerasome (partially ceramic- or silica-coated liposome) has drawn much attention as a novel drug delivery system because its atomic layer of polyorganosiloxane surface imparts higher morphological stability than conventional liposomes and its liposomal bilayer structure reduces the overall rigidity and density greatly compared to silica nanoparticles. Cerasomes are more biocompatible than silica nanoparticles due to the incorporation of the liposomal architecture into cerasomes. Cerasomes combine the advantages of both liposomes and silica nanoparticles but overcome their disadvantages so cerasomes are ideal drug delivery systems. The present review will first highlights some of the key advances of the past decade in the technology of cerasome production and then review current biomedical applications of cerasomes, with a view to stimulating further research in this area of study.     

Crystal structure and magnetic properties of hybrid materials self-assembled from the tetrakis(isothiocyanate)cobaltate(II) anion and trisubstituted benzyltriphenylphosphinium

A new hybrid material [BiF4BrBzTPP]₂[Co(NCS)₄] (1) (BiF4BrBzTPP⁺ = 2,6-bisfluoro-4-bromobenzyl-triphenylphosphinium, NCS^? = isothiocyanate) is synthesized and characterized by elemental analyses, IR, UV spectra, ESI-MS, molar conductivity, single crystal X-ray diffraction and magnetic susceptibility measurements. Compound 1 crystallizes in the monoclinic space group C2/c with a = 15.272(2) Å, b = 24.779(3) Å, c = 14.482(2) Å, β = 101.037(2)°, V = 5378.9(12) ų, Z = 4. The compound comprises two cations and one anion which exhibits a distorted tetrahedral coordination geometry. The short F...F, C...Br, and N...Br interactions and C-H...S hydrogen bonds consolidate the stacking of the molecules. Magnetic susceptibility measurements in the temperature range 2–300 K show that 1 exhibits weak antiferromagnetic coupling behavior.