Hybrid exciton-polaritons in a bad microcavity containing the organic and inorganic quantum wells

We study the hybrid exciton-polaritons in a bad microcavity containing the organic and inorganic quantum wells. The corresponding polariton states are given. The analytical solution and the numerical result of the stationary spectrum for the cavity field are finishedComment: 3 pages, 1 figure. appear in Communications in Theoretical Physic

Evolution of Galaxy Luminosity Function and Luminosity Function by Density Environment at 0.03<z<0.5

Using galaxy sample observed by the BATC large-field multi-color sky survey and galaxy data of SDSS in the overlapped fields, we study the dependence of the restframe $r$-band galaxy luminosity function on redshift and on large-scale environment. The large-scale environment is defined by isodensity contour with density contrast \delta\rho/\rho. The data set is a composite sample of 69,671 galaxies with redshifts 0.03 < z < 0.5 and r < 21.5 mag. The redshifts are composed by three parts: 1) spectroscopic redshifts in SDSS for local and most luminous galaxies; 2) 20-color photometric redshifts derived from BATC and SDSS; 3) 5-color photometric redshifts in SDSS. We find that the faint-end slope \alpha steepens slightly from -1.21 at z ~ 0.06 to -1.35 at z ~ 0.4, which is the natural consequence of the hierarchical formation of galaxies. The luminosity function also differs with different environments. The value of \alpha changes from -1.21 at underdense regions to -1.37 at overdense regions and the corresponding M* brightens from -22.26 to -22.64. This suggests that the fraction of faint galaxies is larger in high density regions than in low density regions.Comment: 7 pages, 9 figures, accepted by Ap

Damage detection of shear connectors in bridge structures with transmissibility in frequency domain

Shear connectors are generally used to link the slab and girder together in slab-on-girder bridge structures. Damage of shear connectors in such structures will result in shear slippage between the slab and girder, which significantly reduces the load-carrying capacity of bridges. A damage detection approach based on transmissibility in frequency domain is proposed in this paper to identify the damage of shear connectors in slab-on-girder bridge structures with or without reference data from the undamaged structure. The transmissibility, which is an inherent system characteristic, indicates the relationship between two sets of response vectors in frequency domain. Measured input force and acceleration responses from hammer tests are analyzed to obtain the frequency response functions at the slab and girder sensor locations by the experimental modal analysis. The transmissibility matrix that relates the slab response to the girder response is then derived. By comparing the transmissibility vectors in undamaged and damaged states, the damage level of shear connectors can be identified. When the measurement data from the undamaged structure are not available, a study with only the measured response data in the damaged state for the condition assessment of shear connectors is also conducted. Numerical and experimental studies on damage detection of shear connectors linking a concrete slab to two steel girders are conducted to validate the accuracy and efficiency of the proposed approach. The results demonstrate that the proposed method can be used to identify shear connector damages accurately and efficiently. The proposed method is also applied to the condition evaluation of shear connectors in a real composite bridge with in-field testing data

Probing for cosmological parameters with LAMOST measurement

In this paper we study the sensitivity of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) project to the determination of cosmological parameters, employing the Monte Carlo Markov Chains (MCMC) method. For comparison, we first analyze the constraints on cosmological parameters from current observational data, including WMAP, SDSS and SN Ia. We then simulate the 3D matter power spectrum data expected from LAMOST, together with the simulated CMB data for PLANCK and the SN Ia from 5-year Supernovae Legacy Survey (SNLS). With the simulated data, we investigate the future improvement on cosmological parameter constraints, emphasizing the role of LAMOST. Our results show the potential of LAMOST in probing for the cosmological parameters, especially in constraining the equation-of-state (EoS) of the dark energy and the neutrino mass.Comment: 7 pages and 3 figures. Replaced with version accepted for publication in JCA

Hawking radiation as tunneling and the unified first law of thermodynamics at the apparent horizon in the FRW universe

Relations between the tunneling rate and the unified first law of thermodynamics at the apparent horizon of the FRW universe are investigated. The tunneling rate arises as a consequence of the unified first law of thermodynamics in such a dynamical system. The analysis shows obviously how the tunneling is intimately connected with the unified first law of thermodynamics through the principle of conservation of energy.Comment: Latex, 9 pages, no figur

Photometric Redshift Determination with the BATC Multicolor System

In this paper, we present the methodology of photometric redshift determination with the BATC 15-color system by using hyperz program. Both simulated galaxies and real galaxies with known redshifts were used to estimate the accuracy of redshifts inferred from the multicolor photometry. From the test with simulated galaxies, the uncertainty in the inferred redshifts is about $0.02\sim0.03$ for a given range of photometric uncertainty of $0.05 \sim 0.10$. The results with the 27 real galaxies are in good agreement with the simulated ones. The advantage of using BATC intermediate-band system to derive redshift is clear through the comparison with the UBVRI broad-band system. The accuracy in redshift determination with BATC system is mainly affected by the selection of filters and the photometric uncertainties in the observation. When we take the limiting magnitudes of the 15 filters into account, we find that redshift can be determined with good accuracy for galaxies with redshifts less than 0.5, using only filters with central wavelengths shorter than 6000 A.Comment: 22 pages, accepted for publishing by PAS

Measurement of the branching fractions of psi(2S) -> 3(pi+pi-) and J/psi -> 2(pi+pi-)

Using data samples collected at sqrt(s) = 3.686GeV and 3.650GeV by the BESII detector at the BEPC, the branching fraction of psi(2S) -> 3(pi+pi-) is measured to be [4.83 +- 0.38(stat) +- 0.69(syst)] x 10^-4, and the relative branching fraction of J/psi -> 2(pi+pi-) to that of J/psi -> mu+mu- is measured to be [5.86 +- 0.19(stat) +- 0.39(syst)]% via psi(2S) -> (pi+pi-)J/psi, J/psi -> 2(pi+pi-). The electromagnetic form factor of 3(pi+pi-) is determined to be 0.21 +- 0.02 and 0.20 +- 0.01 at sqrt(s) = 3.686GeV and 3.650GeV, respectively.Comment: 17pages, 7 figures, submitted to Phys. Rev.

Measurements of J/psi decays into phi pi^0, phi eta, and phi eta^prime

Based on 5.8x10^7 J/psi events detected in BESII, the branching fractions of J/psi--> phi eta and phi eta^prime are measured for different eta and eta^prime decay modes. The results are significantly higher than previous measurements. An upper limit on B(J/psi--> phi pi^0) is also obtained.Comment: 9 pages, 10 figure

Observation of p pbar pi^0 and p pbar eta in psi' decays

The processes psi'-->p pbar pi^0 and psi'-->p pbar eta are studied using a sample of 14 million psi' decays collected with the Beijing Spectrometer at the Beijing Electron-Positron Collider. The branching fraction of psi'-->p pbar pi^0 is measured with improved precision as (13.2\pm 1.0\pm 1.5)\times 10^{-5}, and psi'-->p pbar eta is observed for the first time with a branching fraction of (5.8\pm 1.1\pm 0.7)\times 10^{-5}, where the first errors are statistical and the second ones are systematic.Comment: 15 pages, 8 figures and 3 table

Measurement of the chi_{c2} Polarization in psi(2S) to gamma chi_{c2}

The polarization of the chi_{c2} produced in psi(2S) decays into gamma chi_{c2} is measured using a sample of 14*10^6 psi(2S) events collected by BESII at the BEPC. A fit to the chi_{c2} production and decay angular distributions in psi(2S) to gamma chi_{c2}, chi_{c2} to pi pi and KK yields values x=A_1/A_0=2.08+/-0.44 and y=A_2/A_0=3.03 +/-0.66, with a correlation rho=0.92 between them, where A_{0,1,2} are the chi_{c2} helicity amplitudes. The measurement agrees with a pure E1 transition, and M2 and E3 contributions do not differ significantly from zero.Comment: 6 pages, 4 figures, 1 tabl