Maximum distance separable codes over {\mathbb{Z}_4} and {\mathbb{Z}_2 \times \mathbb{Z}_4}

Known upper bounds on the minimum distance of codes over rings are applied to the case of ${\mathbb Z_{2}\mathbb Z_{4}}$ -additive codes, that is subgroups of ${\mathbb Z_{2}^{\alpha}\mathbb Z_{4}^{\beta}}$ . Two kinds of maximum distance separable codes are studied. We determine all possible parameters of these codes and characterize the codes in certain cases. The main results are also valid when ?? = 0, namely for quaternary linear codes.     

Biomimetic surface preparation of inert polymer films via grafting long monoalkyl chain phosphatidylcholine

To explore construction of novel mimicking biomembrane on biomaterials surfaces,a new polymerizable phosphatidylcholine containing a long monoalkyl chain ended with acryl group(AASOPC) was designed and synthesized, which was easily derived from the terminal amino group of 9-(2-amino-ethylcarbamoyl)-nonyl-1-phosphatidyl-choline (ASOPC) reacting with acryloyl chloride.The obtained AASOPC was grafted on poly(ethylene terephthalate)(PET) via surface-initiated atom-transfer radical polymerization(SI-ATRP) to form mimicking biomembrane.These modified surface structures of PET were investigated using water contact angle(WAC),X-ray photoelectron spectroscopy(XPS) and atomic force microscopy(AFM).The results indicated that the new mimicking phosphatidylcholine biomembrane could be prepared on inert polymer surfaces by using the acryloyl phosphatidylcholine(AASOPC) via surface-initiated atom transfer radical polymerization(SI-ATRP).     

Dynamics of charge carriers at the place of the formation of a muonic atom in diamond and silicon

The space-time distribution of charge carriers at the place of the location of a muonic atom formed when a negative muon is captured by an atom of the lattice has been numerically simulated taking into account the self-consistent electric field. The results of ??SR experiments with negative muons in diamond crystals have been explained and reasons for the difference in the behavior of the spin polarization of the negative muon in boron-doped diamond and in silicon have been revealed. The condition of the validity of the analytical solution of this problem has been obtained. It has been shown that the muonic atom in diamond, in contrast to silicon, does not form a neutral acceptor center in the paramagnetic state during the muon experiment and remains in the diamagnetic state of a positive ion.