Variational Monte Carlo study of chiral spin liquid in the extended Heisenberg model on the Kagome lattice

We investigate the extended Heisenberg model on the Kagome lattice by using Gutzwiller projected fermionic states and the variational Monte Carlo technique. In particular, when both second- and third-neighbor super-exchanges are considered, we find that a gapped spin liquid described by non-trivial magnetic fluxes and long-range chiral-chiral correlations is energetically favored compared to the gapless U(1) Dirac state. Furthermore, the topological Chern number, obtained by integrating the Berry curvature, and the degeneracy of the ground state, by constructing linearly independent states, lead us to identify this flux state as the chiral spin liquid with $C=1/2$ fractionalized Chern number.Comment: 9 pages, 7 figure

The effects of large extra dimensions on associated ttˉh0t\bar{t} h^0 production at linear colliders

In the framework of the large extra dimensions (LED) model, the effects of LED on the processes \rrtth and \eetth at future linear colliders are investigated in both polarized and unpolarized collision modes. The results show that the virtual Kaluza-Klein (KK) graviton exchange can significantly modify the standard model expectations for these processes with certain polarizations of initial states. The process \rrtth with $\sqrt{s}=3.5 TeV$ allows the effective scale $\Lambda_T$ to be probed up to 7.8 and 8.6 TeV in the unpolarized and $P_{\gamma} = 0.9$, J=2 polarized $\gamma \gamma$ collision modes, respectively. For the \eetth process with $\sqrt{s}=3.5 TeV$, the upper limits of $\Lambda_T$ to be observed can be 6.7 and 7.0 TeV in the unpolarized and $P_{e^+} = 0.6$, $P_{e^-} = 0.8$, $-+$ polarized $e^+e^-$ collision modes, respectively. We find the \rrtth channel in J=2 polarized photon collision mode provides a possibility to improve the sensitivity to the graviton tower exchange.Comment: To be appeard in Physical Review

The Impact of Urbanization on Carbon Emission: Empirical Evidence in Beijing

AbstractBased on the historical data in Beijing from 1980 to 2013, this paper uses the ARDL approach to examine the impact of urbanization on carbon emission. The results show that, first, the urbanization level plays a positive role in promoting carbon emission no matter in the long or short term during the sample period. Second, the impact of per capita energy consumption on carbon emission does not seem significant no matter in the long or short term, which is due to the energy efficiency improvement and energy consumption structure adjustment in the past decades. Third, the growth of per capita GDP may curb carbon emission growth in the long term although its impact in the short term does not appear statistically significant, and we find significant inverted U-shaped relationship between per capita GDP and per capita carbon emission in Beijing during the sample period. Finally, there exists significant negative adjusting mechanism from the short term towards the long term among these variables

Effect of insulin pump infusion on comprehensive stress state of patients with diabetic ketoacidosis

Purpose: To assess changes in the comprehensive stress state of patients with diabetic ketoacidosis (DKA) following treatment with insulin infusion pump.Methods: A total of 240 patients suffering from DKA who received treatment at The First Affiliated Hospital of Zhengzhou University from Feb. 2011 to Feb. 2014 were selected randomly and divided into a control group (120 cases), administered continuous intravenous insulin, and a treatment group (120 cases), administered insulin with an infusion pump. Relevant diabetes-associated serum indices, oxidative stress and stress hormone levels were compared between the groups at different time points.Results: Levels of glycosylated haemoglobin (HbAlc), fasting blood glucose (FBG) and anion gap (AG) were lower (p < 0.05) in the treatment group than in the control group at various time points. Carbon dioxide combining power (CO2-CP) and C-reactive peptide levels in the treatment group were higher (p < 0.05) than those of the control group at different time points. Except for the level of methane dicarboxylic aldehyde (MDA), the values of other oxidative stress indices were higher (p < 0.05) in the treatment group than in the control group at various time points. Moreover, the treatment group had lower serum cortisol (Cor) and noradrenalin (NA) levels and higher levels of free triiodothyronine (FT3), free thyroxine (FT4) and thyroid-stimulating hormone (TSH) than those of (p < 0.05).Conclusion: Insulin pump infusion effectively relieves the comprehensive stress state of patients suffering from DKA, and its therapeutic effect is superior to that of continuous instillation of low-dose insulin.Keywords: Diabetic ketoacidosis, Insulin pump, Comprehensive stress state, Blood glucose, Carbon dioxide combining power, C-reactive peptid