In the paper, we show that there is a complex structure on the elliptic surface E(4) with k sections rationally blown down for 2 ≤ k ≤ 9. And we interpret it via Q-Gorenstein smoothings.

Negacyclic BCH codes are a subclass of neagcyclic and the best linear in many cases. However, there have been very few results on negacyclic codes. Let q be an odd prime power m positive integer. The objective this paper is to study with length $$\frac{q^m-1}{2}$$ $$\frac{q^m+1}{2}$$ over finite field $${\textrm{GF}}(q)$$ analyse their parameters. presented good parameters general, contain opti...