Mechanical properties and morphology for polypropylene composites filled with microencapsulated red phosphorus

The effects of the microencapsulated red phosphorus (MRP) content and specimen thickness on the mechanical properties of the filled polypropylene (PP) composites were studied at room temperature. The results showed that the influence of the MRP on the tensile and impact properties of the composites was significant, and the Young's modulus and impact strength of the composites increased nonlinearly while the tensile strength decreased slightly with increasing the MRP weight fraction; the tensile elongation at break increased outstandingly when the MRP weight fraction was less than 2% and then decreased with increasing the MRP weight fraction. Furthermore, the impact fracture surface was examined by scanning electronic microscope. The results suggested that the toughening effect was attributed to the absorption of impact fracture energy by the microencapsulated layer. Copyright © 2014 John Wiley & Sons, Ltd.     

原子团簇P6同分异构体的可能性

使用分子图形学方法设计出 2 3种可能的同分异构体 ,并对其进行了分子力学、PM3半经验量子化学和 ADF密度泛函优化。在 P6原子团簇模型设计中 ,磷原子采用一、二、三或四配位。从各异构体的比较可得知 ,由正四面体 P4派生出的结构在能量方面具有优势。椅式结构、船式结构和平面结构的能量依次增大     

Scanning Kelvin probe study of photolabile silane surface modification of indium tin oxide

The scanning Kelvin nanoprobe (SKN) is an exquisitely sensitive device capable of detecting subtle changes in work function associated with alteration of surface chemistry and interfacial dipole. This instrument is highly versatile and has notably been recently used for (i) the investigation of biological interactions occurring at the interface of multiplexed microarrayed platforms and (ii) the characterization of high work function materials for application in molecular optoelectronics. Herein, we further implement the SKN to characterize, along with angle‐resolved X‐ray photoelectron spectroscopy and contact angle goniometry, the surface modification of indium tin oxide substrates with photopatternable silane adlayers. These molecular films are constructed in a straightforward and economical manner from alkyltrichlorosilane surface‐modifying molecules that possess a distal, UV‐photolabile o‐nitrobenzyl moiety. Employing a photomask, we were able to selectively pattern regions of the photoreactive silane adlayer and confirm the corresponding changes in surface potential through contact potential difference measurements. Copyright © 2013 John Wiley & Sons, Ltd.     

Minimizing finite-size effects in artificial resonance tunneling structures

We consider finite-size effects in coupled cavity structures. Starting with microring resonator structures well described by transfer matrices, we obtain conditions that lead to the minimization of finite-size effects. Our approach does not require numerical optimization and requires only slight modification of design parameters guided by closed-form analytical expressions. Using a Breit-Wigner scattering formalism, we demonstrate that the scheme can be used to minimize finite-size effects in a general class of coupled cavity structures. The strength of the present technique lies in its simplicity and its applicability to a wide variety of structures described by tight-binding formalisms.     

Virtual screening for anti-HIV-1 RT and anti-HIV-1 PR inhibitors from the Thai medicinal plants database: a combined docking with neural networks approach

The virtual screening approach for docking small molecules into a known protein structure is a powerful tool for drug design. In this work, a combined docking and neural network approach, using a self-organizing map, has been developed and applied to screen anti-HIV-1 inhibitors for two targets, HIV-1 RT and HIV-1 PR, from active compounds available in the Thai Medicinal Plants Database. Based on nevirapine and calanolide A as reference structures in the HIV-1 RT binding site and XK-263 in the HIV-1 PR binding site, 2,684 compounds in the database were docked into the target enzymes. Self-organizing maps were then generated with respect to three types of pharmacophoric groups. The map of the reference structures were then superimposed on the feature maps of all screened compounds. Only the structures having similar features to the reference compounds were accepted. By using the SOMs, the number of candidates for HIV-1 RT was reduced to six and nine compounds consistent with nevirapine and calanolide A, respectively, as references. For the HIV-1 PR target, there are 135 screened compounds showed good agreement with the XK-263 feature map. These screened compounds will be further tested for their HIV-1 inhibitory affinities. The obtained results indicate that this combined method is clearly helpful to perform the successive screening and to reduce the analyzing step from AutoDock and scoring procedure.     

OXIDATIVE COUPLING OF METHANE OVER Na_2CO_3 DOPED ZIRCONIUM DIORIDE

Na_2CO_3/ZrO_2 catalyst shows a high activity of oxidative coupling of methane. It possesses stronger electron donor ability than that of ZrO_2 catalyst. The activation of methane is supposed to relate to the O_2~- or O_2~(2-) and O~- species.     

A new family of tunable indolylphosphine ligands by one-pot assembly and their applications in Suzuki-Miyaura coupling of aryl chlorides

This study describes a new class of indolylphosphine ligands, which can be easily accessed by a simple one-pot assembly from commercially available indoles, acid chlorides, and chlorophosphines. A combination of these three starting materials provides a high diversification of the ligand structure. The application of this ligand array in palladium-catalyzed Suzuki-Miyaura coupling reaction of aryl chlorides with arylboronic acids is described. A catalyst loading down to 0.01 mol % of Pd can be achieved.