Semi-classical States in Homogeneous Loop Quantum Cosmology

Semi-classical states in homogeneous loop quantum cosmology (LQC) are constructed by two different ways. In the first approach, we firstly construct an exponentiated annihilation operator. Then a kind of semi-classical (coherent) state is obtained by solving the eigen-equation of that operator. Moreover, we use these coherent states to analyze the semi-classical limit of the quantum dynamics. It turns out that the Hamiltonian constraint operator employed currently in homogeneous LQC has correct classical limit with respect to the coherent states. In the second approach, the other kind of semi-classical state is derived from the mathematical construction of coherent states for compact Lie groups due to Hall.Comment: 13 pages, submitted to CQ

Stable, Efficient, and All-Solution-Processed Quantum Dot Light-Emitting Diodes with Double-Sided Metal Oxide Nanoparticle Charge Transport Layers

Cataloged from PDF version of article.An efficient and stable quantum dot light-emitting diode (QLED) with double-sided metal oxide (MO) nanoparticle (NP) charge transport layers is fabricated by utilizing the solution-processed tungsten oxide (WO3) and zinc oxide (ZnO) NPs as the hole and electron transport layers, respectively. Except for the electrodes, all other layers are deposited by a simple spin-coating method. The resulting MO NP-based QLEDs show excellent device performance, with a peak luminance of 21300 cd/m(2) at the emission wavelength of 516 nm, a maximal current efficiency of 4.4 cd/A, and a low turn-on voltage of 3 V. More importantly, with the efficient design of the device architecture, these devices exhibit a significant improvement in device stability and the operational lifetime of 95 h measured at room temperature can be almost 20-fold longer than that of the standard device

Expression and distribution of HIF-1α, HIF-2α, VEGF, VEGFR-2 and HIMF in the kidneys of Tibetan sheep, plain sheep and goat

Background: The objective of this study was to detect the expression and distribution characteristics of five proteins (the hypoxia-inducible factor 1alpha [HIF-1a], HIF-2a, vascular endothelial growth factor [VEGF], VEGF-2 receptor [VEGFR-2] and hypoxia-induced mitogenic factor [HIMF]) in kidney of Tibetan sheep, plain sheep and goat. The results will provide the basic information for the comparative study of sheep breeds living at different altitudes.Materials and methods: The kidney tissues were collected from healthy adult Tibetan sheep, plain sheep and goats and made into paraffin sections. Histological characteristics were assessed by haematoxylin and eosin staining. Expressions of HIF-1a, HIF-2a, VEGF, VEGFR-2 and HIMF proteins were measured by immunohistochemical staining.Results: Immunohistochemistry results showed that the positive expression signals of HIF-1a, HIF-2a, VEGF and VEGFR-2 were detected in epithelial cells of renal tubules and collecting tubules, renal corpuscles in the kidneys of the three sheep breeds. Positive expression signals of HIMF were detected in epithelial cells of proximal tubules and distal tubules in Tibetan sheep and epithelial cells of distal tubules in goat. Immunostaining intensity of HIF-1a, HIF-2a, VEGF and VEGFR-2 proteins in Tibetan sheep was significantly higher than that in both plain sheep and goat (p < 0.05). Immunostaining intensity of HIMF in Tibetan sheep was higher than goat (p < 0.05). Positive expression signals of HIMF were not detected in plain sheep.Conclusions: The expression and distribution characteristics of HIF-1a, HIF-2a, VEGF, VEGFR-2 and HIMF in the studied kidney tissues suggested that these proteins may be related to the physiological regulation of Tibetan sheep kidney in hypoxia environment, and therefore might be important regulating proteins for Tibetan sheep to adapt to high altitude hypoxia environment

Search for psi(3770)\ra\rho\pi at the BESII detector at the Beijing Electron-Positron Collider

Non-$D\bar{D}$ decay \psppto \rhopi is searched for using a data sample of $(17.3\pm 0.5) pb^{-1}$ taken at the center-of-mass energy of 3.773 GeV by the BESII detector at the BEPC. No \rhopi signal is observed, and the upper limit of the cross section is measured to be \sigma(\EETO \rhopi)<6.0 pb at 90% C. L. Considering the interference between the continuum amplitude and the \pspp resonance amplitude, the branching fraction of \pspp decays to $\rho\pi$ is determined to be \BR(\pspp\ra\rho\pi)\in(6.0\times10^{-6}, 2.4\times10^{-3}) at 90% C. L. This is in agreement with the prediction of the $S$- and $D$-wave mixing scheme of the charmonium states for solving the ``\rhopi puzzle'' between \jpsi and \psp decays.Comment: 15 pages, 5 figure

Cross-sectional comparisons of sodium content in processed meat and fish products among five countries: potential for feasible targets and reformulation.

INTRODUCTION: Reducing sodium intake has been identified as a highly cost-effective strategy to prevent and control high blood pressure and reduce cardiovascular mortality. This study aims to compare the sodium content in processed meat and fish products among five countries, which will contribute to the evidence-base for feasible strategies of sodium reduction in such products. METHODS: Sodium content on product labels of 26 500 prepackaged products, 19 601 meat and 6899 fish, was collected in supermarkets from five countries using the FoodSwitch mobile application from 2012 to 2018. To be specific, it was 1898 products in China, 885 in the UK, 5673 in Australia, 946 in South Africa and 17 098 in the USA. Cross-sectional comparisons of sodium levels and proportions meeting 2017 UK sodium reduction targets were conducted using Kruskal-Wallis H and the χ2 test, respectively across the five countries. RESULTS: The results showed that processed meat and fish products combined in China had the highest sodium level (median 1050 mg/100 g, IQR: 774-1473), followed by the USA, South Africa, Australia, with the lowest levels found in UK (432 mg/100 g, IQR: 236-786) (p<0.001). Similar variations, that is, a twofold to threefold difference of sodium content between the highest and the lowest countries were found among processed meat and fish products separately. Large sodium content variations were also found in certain specific food subcategories across the five countries, as well as across different food subcategories within each country. CONCLUSION: Processed meat and fish products differ greatly in sodium content across different countries and across different food subcategories. This indicates great potential for food producers to reformulate the products in sodium content, as well as for consumers to select less salted food

Measurements of the continuum RudsR_{\rm uds} and RR values in e+e−e^+e^- annihilation in the energy region between 3.650 and 3.872 GeV

We report measurents of the continuum $R_{\rm uds}$ near the center-of-mass energy of 3.70 GeV, the $R_{{\rm uds(c)}+\psi(3770)}(s)$ and the $R_{\rm had}(s)$ values in $e^+e^-$ annihilation at 68 energy points in the energy region between 3.650 and 3.872 GeV with the BES-II detector at the BEPC Collodier. We obtain the $R_{\rm uds}$ for the continuum light hadron (containing u, d and s quarks) production near the $D\bar D$ threshold to be $R_{\rm uds}=2.141 \pm 0.025 \pm 0.085$.Comment: 5 pages, 3 figure

Experimental study of ψ(2S)\psi(2S) decays to \K^+ K^- \pi^+ \pi^- \pi^0 final states

$K^+K^-\pi^+\pi^-\pi^0$ final states are studied using a sample of $14\times10^6$ $\psi(2S)$ decays collected with the Beijing Spectrometer (BESII) at the Beijing Electron-Position Collider. The branching fractions of $\psi(2S)$ decays to $K^+K^-\pi^+\pi^-\pi^0$, $\omega K^+ K^-$, $\omega f_0(1710)$, $K^{\ast}(892)^0 K^- \pi^+\pi^0+c.c.$, $K^{\ast}(892)^{+} K^- \pi^+\pi^- +c.c.$, $K^{\ast}(892)^{+} K^- \rho^0+c.c.$ and $K^{\ast}(892)^0 K^-\rho^+ + c.c.$ are determined. The first two agree with previous measurements, and the last five are first measurements.Comment: 19 pages, 9 figure

Partial Wave Analysis of χc0→π+π−K+K−\chi_{c0}\to\pi^+\pi^-K^+K^-

A partial wave analysis of $\chi_{c0}\to\pi^+\pi^-K^+K^-$ in $\psi(2S)\to\gamma\chi_{c0}$ decay is presented using a sample of 14 million $\psi(2S)$ events accumulated by the BES II detector. The data are fitted to the sum of relativistic covariant tensor amplitudes for intermediate resonant decay modes. From the fit, significant contributions to $\chi_{c0}$ decays from the channels $f_0(980)f_0(980)$, $f_0(980)f_0(2200)$, $f_0(1370)f_0(1710)$, $K^*(892)^0\bar K^*(892)^0$, $K^*_0(1430)\bar K^*_0(1430)$, $K^*_0(1430)\bar K^*_2(1430) + c.c.$, and $K_1(1270)K$ are found. Flavor-SU(3)-violating $K_1(1270)-K_1(1400)$ asymmetry is observed. Values obtained for the masses and widths of the resonances $f_0(1710)$, $f_0(2200)$, $f_0(1370)$, and $K^*_0(1430)$ are presented.Comment: 16 pages, 9 figures, and 4 table

First observation of ψ(2S)→pnˉπ−+c.c.\psi(2S) \to p \bar{n} \pi^- +c.c.

Using 14 million $\psi(2S)$ events collected with the Beijing Spectrometer (BESII) at the Beijing Electron-Positron Collider, the branching fractions of $\psi(2S)$ decays to $p \bar{n} \pi^-$ and $\bar{p} n \pi^+$ and the branching fractions of the main background channels $\psi(2S) \to p \bar{n} \pi^-\pi^0$, $\psi(2S) \to \gamma\chi_{c0} \to \gamma p \bar{n} \pi^-$, $\psi(2S) \to \gamma\chi_{c2} \to \gamma p \bar{n} \pi^-$, and $\psi(2S) \to \gamma \chi_{cJ} \to \gamma p \bar{n} \pi^- \pi^0$ are determined. The contributions of the $N^{\ast}$ resonances in $\psi(2S) \to p \bar{n} \pi^- +c.c.$ are also discussed.Comment: 19 pages, 8 figures, add vertex requirement systematic erro