No abstract

No abstract

High electromagnetic shielding performance was achieved in the Mg-9Li-3Al-1Zn alloy processed by accumulative roll bonding (ARB). The microstructure, electromagnetic interference shielding effectiveness (SE) in the frequency of 30-1500 MHz and mechanical properties of the alloy were investigated. A model based on the shielding of the electromagnetic plane wave was used to theoretically discuss the EMI shielding mechanisms of ARB-processed alloy. Results indicate that the SE of the material increases gradually with the increase in the ARB pass. The enhanced SE can be attributed to the obvious microstructure orientation caused by ARB, and the alternative arrangement of alpha(Mg) phase and beta(Li) phase. In addition, with the increase in ARB pass, the number of interfaces between layers increases and the grain orientation of each layer tends to alignment along c-axis, which is beneficial to the reflection loss and multiple reflection loss of the incident electromagnetic wave.

Asymmetric hydrogenations of a series of β-amino ketones were carried out with a bimetallic complex (RuPHOX-Ru) as the chiral catalyst. Almost all the reactions (performed in a mixed solvent system of toluene and H2O in the presence of KOH) gave quantitative conversions into their respective products with up to 99.9% ee. The RuPHOX-Ru catalyst is stable to both moisture and air. The procedure has the benefits of being inexpensive, environmentally friendly and highly efficient. Under a relatively low catalyst loading (TON = 2000), key intermediates of fluoxetine, tomoxetine and nisoxetine could be obtained in quantitative yield and in up to 99.9% ee. This methodology represents a promising alternative to the synthesis of the aforementioned drugs and their analogues.

No abstract