Search

We propose an adaptive parameter alternating direction algorithm to solve a class of generalized coupled Sylvester-transpose matrix equations over centrosymmetric matrices. Under appropriate constraints, we prove that the algorithm is convergent. Finally, we illustrate the feasibility and effectiveness of this method through numerical experiments. [ABSTRACT FROM AUTHOR]

MXenes are attracting much attention as electrode materials due to their excellent energy storage and electrochemical properties. More interestingly, the energy storage capacities of MXenes have been found to strongly depend on the surface terminal groups. Here, first-principles calculations were performed to investigate the geometric stability, electrochemical properties and Na storage capability of Nb2CT2 (T = O, S, Se, Cl or Br) systems based on density functional theory. The results reveal that the superior properties such as good electronic conductivity, fast charge–discharge rates, low open circuit voltage and high theoretical Na storage capacity make Nb2CS2 and Nb2CCl2 applicable for novel anode materials in sodium-ion batteries (SIBs) compared with the other Nb2CT2 (T = O, Se or Br) MXenes. Moreover, S- and Cl-functionalization can yield expanded interlayer spacing, improving the Na ion accessibility in Nb2CT2. These findings provide guidance for the design of MXene-based anode materials in SIBs. [ABSTRACT FROM AUTHOR]

• We proposed an iterative algorithm for a class of generalized coupled Sylvester-conjugate matrix equations over generalized Hamiltonian matrix. • We proved the proposed algorithm is finitely terminated. • Some numerical examples are tested to verify the efficiency and stability of the proposed algorithm. In this work, we present an iterative algorithm to solve a class of generalized coupled Sylvester-conjugate matrix equations over the generalized Hamiltonian matrices. We show that if the equations are consistent, a generalized Hamiltonian solution can be obtained within finite iteration steps in the absence of round-off errors for any initial generalized Hamiltonian matrix by the proposed iterative algorithm. Furthermore, we can obtain the minimum-norm generalized Hamiltonian solution by choosing the special initial matrices. Finally, numerical examples show that the iterative algorithm is effective. [ABSTRACT FROM AUTHOR]

In this work, we introduce a modified generalized shift-splitting (MGSS) iteration method for a class of complex symmetric linear systems. Meanwhile, we establish the convergence analysis and give the spectral properties of the corresponding preconditioned matrix. Finally, a numerical example illustrates the effectiveness of the MGSS. [ABSTRACT FROM AUTHOR]

The asymmetrical structures were created by inserting a low-indium-content layer between the QW and barrier to form a step-like quantum barrier (QB) at one side of QW. The optical effects of the inserting layer on QW emission were investigated with low-temperature photoluminescence (PL) and time-resolved PL (TRPL). The inserted layer partially relaxed the strain within QW layer and induced about 25 nm red-shift in the PL emission compared with conventional QW, while the presence of localization centers around QW affected the emission mechanism and increased the radiative decay time. Furthermore, the position of the inserted layer played different roles in the changed structures, and whilst the n-side step-barrier exhibited strong localization in the energy levels of the inserted layer, the p-side step-barrier showed stronger localization center for the QW levels. [ABSTRACT FROM AUTHOR]