Fluorinated poly(p-triphenyl piperidine) anion exchange membranes with robust dimensional stability for fuel cells.

Anion exchange membrane fuel cells (AEMFCs), which are more economical than proton exchange membrane fuel cells (PEMFCs), stand out in the context of the rapid development of renewable energy. Superacid-catalyzed ether-free aromatic polymers have recently received a lot of attention due to their exceptional performance, but their development has been hampered by the trade-off between the dimensional stability and ionic conductivity of anion exchange membranes (AEMs). Here, we introduced fluoroketones containing different numbers of fluorinated groups (x = 0, 3 and 6) in the main chain of p-terphenyl piperidine because of the favorable hydrophobic properties of fluorinated groups.

Effects of the crown ether cavity on the performance of anion exchange membranes.

Anion exchange membrane fuel cells (AEMFCs) have emerged as a promising alternative to proton exchange membrane fuel cells (PEMFCs) due to their adaptability to low-cost stack components and non-noble-metals catalysts. However, the poor alkaline resistance and low OH conductivity of anion exchange membranes (AEMs) have impeded the large-scale implementation of AEMFCs. Herein, the preparation of a new type of AEMs with crown ether macrocycles in their main chains via a one-pot superacid catalyzed reaction was reported.

[Ecological functions of E-β-farnesene on aphids and their natural enemies in potato field.].

As a most common component of aphid alarm pheromone, E-β-farnesene (EβF) could not only dispel aphids, but also modify some behavioral responses of their natural enemies. In order to investigate the ecological function of EβF, its influence on the population dynamics of Myzus persicae (Sulzer), Aphis gossypii (Glover), Macrosiphum euphorbiaein (Thomas) and their natural enemies was studied in potato fields. The results showed that there were significantly lower aphid abundance (2012, 2013), higher ladybird beetle abundance (2012, 2013), and higher mummified aphid abundance (2012) on potato plants in EβF treated plots (100 μL per week).

Preparative resolution of gatifloxacin enantiomers with pre-column esterification strategy and comparing their enantioselectivity to bacteria and antibody.

Gatifloxacin (GFX) is a kind of chiral fluoroquinolones compound due to the methyl group at the C-3 position of the piperazine ring[1]. Although the enantiomers of GFX show similar levels of antimicrobial activity and pharmacokinetics[2], the other biological activities (i.e.

Phototactic behavior of the Armand pine bark weevil, Pissodes punctatus.

The Armand pine bark weevil, Pissodes punctatus Langor et Zhang (Coleoptera: Curculionidae) is a destructive bark weevil on the Armand pine, Pinus armandii Franch (Pinales: Pinaceae), an important timbering tree in southern China. This study examined the phototactic behavior ïéP. punctatus through observation of behavioral characteristics, response to nine monochromatic lights (ranging from 340 nm to 689 nm with about 40-nm step), and response to five intensities (ranging from 1 lux to 200 lux) of the most attractive light.