Ground-state phase diagram of an anisotropic spin-1/21/2 model on the triangular lattice

Motivated by the recent experiment on a rare-earth material YbMgGaO$_4$ [Y. Li \textit{et al.}, Phys. Rev. Lett. \textbf{115}, 167203 (2015)], which found that the ground state of YbMgGaO$_4$ is a quantum spin liquid, we study the ground-state phase diagram of an anisotropic spin-$1/2$ model that was proposed to describe YbMgGaO$_4$. Using the density-matrix renormalization group method in combination with the exact diagonalization, we calculate a variety of physical quantities, including the ground-state energy, the fidelity, the entanglement entropy and spin-spin correlation functions. Our studies show that in the quantum phase diagram there is a $120^{\circ}$ phase and two distinct stripe phases. The transitions from the two stripe phases to the $120^{\circ}$ phase are of the first order. However, the transition between the two stripe phases is not the first order, which is different from its classical counterpart. Additionally, we find no evidence for a quantum spin liquid in this model. Our results suggest that additional terms may be also important to model the material YbMgGaO$_4$. These findings will stimulate further experimental and theoretical works in understanding the quantum spin liquid ground state in YbMgGaO$_4$.Comment: minor change

The evolution of magnetic structure driven by a synthetic spin-orbit coupling in two-component Bose-Hubbard model

We study the evolution of magnetic structure driven by a synthetic spin-orbit coupling in a one-dimensional two-component Bose-Hubbard model. In addition to the Mott insulator-superfluid transition, we found in Mott insulator phases a transition from a gapped ferromagnetic phase to a gapless chiral phase by increasing the strength of spin-orbit coupling. Further increasing the spin-orbit coupling drives a transition from the gapless chiral phase to a gapped antiferromagnetic phase. These magnetic structures persist in superfluid phases. In particular, in the chiral Mott insulator and chiral superfluid phases, incommensurability is observed in characteristic correlation functions. These unconventional Mott insulator phase and superfluid phase demonstrate the novel effects arising from the competition between the kinetic energy and the spin-orbit coupling.Comment: 9 fig; English polished, note adde

Understanding User’s Switching Intention on Mobile Payment Platforms

With the development of mobile payment (m-payment) service, the competition accordingly increases among m-payment market. Users face multiple choices when adopting m-payment services. It is critical for both scholars and m-payments providers to understand what the underlying factors can influence user’s switching from one incumbent m-payment platform to another. To solve this question, we employ a push-pull-mooring (PPM) framework to build the research model. We propose that user’s dissatisfaction on incumbent m-payment provider is the main push factor for user’s switching. The attractiveness of alternative and peer influence are the pull factors influencing user’s switching. Cognitive lock-in, as the mooring factor, could influence switching intention directly. Additionally, we posit that cognitive lock-in can moderate the effects of both push and pull factors on user’s switching intention. This study will use survey methodology and structural equation modelling approach to test the hypotheses

Ground-state phase diagram of the frustrated spin-1/2 two-leg honeycomb ladder

We investigate a spin-$1/2$ two-leg honeycomb ladder with frustrating next-nearest-neighbor (NNN) coupling along the legs, which is equivalent to two $J_1$-$J_2$ spin chains coupled with $J_\perp$ at odd rungs. The full parameter region of the model is systematically studied using conventional and infinite density-matrix renormalization group as well as bosonization. The rich phase diagram consists of five distinct phases: A Haldane phase, a NNN-Haldane phase and a staggered dimer phase when $J_{\perp} < 0$; a rung singlet phase and a columnar dimer phase when $J_{\perp} > 0$. An interesting reentrant behavior from the dimerized phase into the Haldane phase is found as the frustration $J_2$ increases. The universalities of the critical phase transitions are fully analyzed. Phase transitions between dimerized and disordered phases belong to the two-dimensional Ising class with central charge $c=1/2$. The transition from the Haldane phase to NNN-Haldane phase is of a weak topological first order, while the continuous transition between the Haldane phase and rung singlet phase has central charge $c=2$.Comment: 14 pages, 17 figures, for latest version and additional information see https://www.physik.uni-kl.de/eggert/papers/index.htm

Enhancement of recombinant myricetin on the radiosensitivity of lung cancer A549 and H1299 cells

OBJECTIVE: Myricetin, a common dietary flavonoid is widely distributed in fruits and vegetables, and is used as a health food supplement based on its immune function, anti-oxidation, anti-tumor, and anti-inflammatory properties. The aim of this study was to investigate the effects of myricetin on combination with radiotherapy enhance radiosensitivity of lung cancer A549 and H1299 cells. METHODS: A549 cells and H1299 cells were exposed to X-ray with or without myricetin treatment. Colony formation assays, CCK-8 assay, flow cytometry and Caspase-3 level detection were used to evaluate the radiosensitization activity of myricetin on cell proliferation and apoptosis in vitro. Nude mouse tumor xenograft model was built to assessed radiosensitization effect of myricetin in vivo. RESULTS: Compared with the exposed group without myricetin treatment, the groups treated with myricetin showed significantly suppressed cell surviving fraction and proliferation, increased the cell apoptosis and increased Caspase-3 protein expression after X-ray exposure in vitro. And in vivo assay, growth speed of tumor xenografts was significantly decreased in irradiated mice treated with myricetin. CONCLUSIONS: The study demonstrated both in vitro and in vivo evidence that combination of myricetin with radiotherapy can enhance tumor radiosensitivity of pulmonary carcinoma A549 and H1299 cells, and myricetin could be a potential radiosensitizer for lung cancer therapy. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/579151800121063

Optimal batching plan of deoxidation alloying based on principal component analysis and linear programming

As the market competition of steel mills is severe, deoxidization alloying is an important link in the metallurgical process. To solve this problem, principal component regression analysis is adopted to reduce the dimension of influencing factors, and a reasonable and reliable prediction model of element yield is established. Based on the constraint conditions such as target cost function constraint, yield constraint and non-negative constraint, linear programming is adopted to design the lowest cost batting scheme that meets the national standards and production requirements. The research results provide a reliable optimization model for the deoxidization and alloying process of steel mills, which is of positive significance for improving the market competitiveness of steel mills, reducing waste discharge and protecting the environment