A quasi-one-dimensional analytical method with a novel model for precombustion shock train has been proposed to model different modes in the dual-mode scramjet flowfield. The interaction between shock and combustion is modeled by a strength-adaptable model in the isolator, named the "X shock." An iterative procedure is implemented to solve the precombustion shock and the flow properties downstream. The calculation of the combustor is based on a series of governing equations where the effects of area change, friction, and mass injection are included. The release of energy is obtained from a fuel-mixing model or pregiven heat release distributions estimated from experimental results. The numerical results of pressure are compared with the experimental data for validation of the present model. The results show that the quasi-one-dimesional method can be applied to analyze diverse modes in the whole process of the dualmode scramjet combustor. Subscripts in = conditions in the inlet of the isolator max = maximum value min = minimum value 0 = total or stagnation conditions
The entanglement dynamics of two-qubit systems in different quantum noises are investigated by means of the operator-sum representation method. We find that, except for the amplitude damping and phase damping quantum noise, the sudden death of entanglement is always observed in different two-qubit systems with generalized amplitude damping and depolarizing quantum noise.
Using reverse transcription polymerase chain reaction (RT-PCR), three full-length cDNAs of ω-6 desturases (FAD2) were obtained from three wild potato species (Solanum commersonii, S. acaule, and S. cardiophyllum) with different levels of freezing tolerance and cold acclimation capacity. These genes were designated Cmm-FAD2 (GenBank accession No. KF214782), Aca-FAD2 (KF214781), and Cph-FAD2 (KF214783), respectively. They are all 1326 bp in length, coding 441 amino acids. The alignment result indicated that eight of 18 different nucleotides result in the corresponding variation of coding proteins in the three species. At the amino acid positions of No. 11 and No. 44, amino acid residues of S. commersonii and S. acaule are different from that of S. cardiophyllum. The results of secondary structure prediction showed obvious differences in alpha-helix, extend chain, and random crimp of S. commersonii and S. acaule as compared to those of S. cardiophyllum. According to the alignment result of multiple protein sequences and the phylogenetic tree, the coding products of FAD2 genes from the three wild potato species are highly homologous to those from tomato and purslane. The results of qPCR showed that FAD2 expression was up-regulated in the three potato wild species after 12-day cold acclimation; however, the relative expression level of FAD2 in S. commersonii and S. acaule were significantly higher than that in S. cardiophyllum.