In this paper, we study λ-constacyclic codes over the ring R = Z4 + uZ4, where u^2 = 0, for λ= 1 + 3u and 3 + u. We introduce two new Gray maps from R to Z4^4 and show that the Gray images of λ-constacyclic cod...In this paper, we study λ-constacyclic codes over the ring R = Z4 + uZ4, where u^2 = 0, for λ= 1 + 3u and 3 + u. We introduce two new Gray maps from R to Z4^4 and show that the Gray images of λ-constacyclic codes over R are quasi-cyclic over Z4. Moreover, we present many examples of λ-constacyclic codes over R whose Z4-images have better parameters than the currently best-known linear codes over Z4.展开更多
The uplift indicated by five AFT (apatite fission track) samples is more than 3400 m by multi-episodic uplift since Late Cretaceous in Zoige area; especially the processes of fast uplift in Late Cretaceous and Neogene...The uplift indicated by five AFT (apatite fission track) samples is more than 3400 m by multi-episodic uplift since Late Cretaceous in Zoige area; especially the processes of fast uplift in Late Cretaceous and Neogene have important influences on the stress of paleo-fluid. Based on field geology, macroscopic features of fracture, and geochemistry of fluid inclusions, we decipher the paleo-fluid process of episodic migration. In early uplift stage, the temperature of inclusions increased with the constant salinity, whilst both of them proportionally decreased in the mid-late stage, indicating the different tendency of heat-fluid warming and freshwater contamination at different time. Of particular importance are the features of episodic fluid flow, such as ESR ages, and features of multi-episodic migration that correspond well with the process of multi-episodic uplift. Thus, concerning the rock stress-strain behavior responding to uplift, we further discuss the spatio-temporal coupling effect of episodic migration and decompression in multi-episodic uplift, thereby to better understand petroleum geology in the region.展开更多
文摘In this paper, we study λ-constacyclic codes over the ring R = Z4 + uZ4, where u^2 = 0, for λ= 1 + 3u and 3 + u. We introduce two new Gray maps from R to Z4^4 and show that the Gray images of λ-constacyclic codes over R are quasi-cyclic over Z4. Moreover, we present many examples of λ-constacyclic codes over R whose Z4-images have better parameters than the currently best-known linear codes over Z4.
文摘The uplift indicated by five AFT (apatite fission track) samples is more than 3400 m by multi-episodic uplift since Late Cretaceous in Zoige area; especially the processes of fast uplift in Late Cretaceous and Neogene have important influences on the stress of paleo-fluid. Based on field geology, macroscopic features of fracture, and geochemistry of fluid inclusions, we decipher the paleo-fluid process of episodic migration. In early uplift stage, the temperature of inclusions increased with the constant salinity, whilst both of them proportionally decreased in the mid-late stage, indicating the different tendency of heat-fluid warming and freshwater contamination at different time. Of particular importance are the features of episodic fluid flow, such as ESR ages, and features of multi-episodic migration that correspond well with the process of multi-episodic uplift. Thus, concerning the rock stress-strain behavior responding to uplift, we further discuss the spatio-temporal coupling effect of episodic migration and decompression in multi-episodic uplift, thereby to better understand petroleum geology in the region.