Search

The Stellar Abundances and Galactic Evolution Survey (SAGES) is a multi-band photometric survey focused on estimation of stellar atmospheric parameters and interstellar extinction. In this paper we have derived photonic passbands for the intermediate-band u and v filters of the SAGES photometric system. The derived photonic passbands have been compared with those of the u and v filters of the Strömgren and SkyMapper systems. Synthetic photometry based on the derived photonic passbands could reproduce the observations very well. We have also derived observed, model-free extinction coefficients for the SAGES u and v bands (as well as the Pan-STARRS grizy bands) using the “standard pair” method. The derived reddening coefficients have been compared with those predicted by the extinction laws. Variations of reddening coefficients with effective temperatures and color excesses of B–V given by Schlegel et al. (E(B−V)SFD) have been investigated. No obvious trends or significant variations with effective temperatures have been found, but reddening coefficients for all the colors exhibit declining trends with increasing E(B−V)SFD, with typical relative variations of twenty-some percent from E(B − V)SFD ∼ 0 to 1.

The article presents the latest status of the Maidanak 1 m telescope, instruments and the related facilities of the Observatory as well as the science projects. The renovation of the 1 m telescope of Carl Zeiss (Germany) at the Maidanak observatory of the Ulug Bek Astronomical Institute (UBAI) AS of Uzbekistan has been made. All systems of the telescope were completely modernized based on modern standards, the main results of modernization are also described. All modernization works, as well as scientific research on this project are carried out in close cooperation of UBAI with the National Astronomical Observatories of the Academy of Sciences of the PRC in framework of the Agreement on cooperation between these organizations. The FOV has been enlarged and new CCD camera is mounted. The related facilities, like the observing circumstance monitoring system and the photovoltaic station, are also built for the observing support. The telescope and new camera will be tested and used for the science projects of the 1 m telescope. According to the collaboration agreement, a large-scale scientific project on a full survey of the northern sky in special photometric system - Stellar Abundance and Galactic Evolution (SAGE) survey will be carried out with the upgraded 1 m telescope. The main goal of the project is to measure the stellar atmospheric parameters for more than 500 million FGK stars. As other projects, the time domain science, like GRB, SNe searching, variable stars, also will be performed.

This study continued the investigation into the mechanical properties of high strength concrete filled steel tubular columns, (HSCFST). The test results for slender columns show that the load bearing capacities and maximum displacement ratio (the ratio of displacement to the initial length at peak load) of the column decreases as slenderness ratio, determined as the ratio of the length to diameter, increases. The test results for eccentrically loaded columns show that when the slenderness ratio is kept constant, the load bearing capacity and maximum strain decrease as the eccentricity ratio increases, with the eccentricity ratio defined as the ratio as the ratio of eccentricity to radius. The formula for calculating the load bearing capacities of slender columns and the eccentrically loaded columns are presented in the paper. These formulas are designed for inclusion in design code documents.

This study investigated the mechanical properties of High Strength Concrete filled steel tubular short columns (HSCFSTSC) with length to diameter ratio (L/D) of 3.5.The strength of concrete used to fill the steel tubular columns ranged from 54MPa to 116MPa. The test results showed that using a steel tube as confinement can significantly improve the ductility and compressive strength of core concrete. The magnitude of compressive strength increase of core concrete was directly proportional to the Confinement Index, , and the extent of improvement of the ductility increases as the  increases. For thoroughly improving the ductility of core concrete, the Confinement Index  should be equal or larger than 0.48. The formula used to calculate the load bearing capacity of HSCFSTSC was given out.

An experiment was undertaken to investigate the effect of mineral admixtures, w/b, external chloride solution concentration, and carbonation on chloride binding capacity of cementitious paste. The test method was based on equilibrium method. Test results show that incorporating metakaolin, blastfurnace slag, steel slag, and flyash increases chloride binding capacities by 65.9%, 55.3%, 43.9%, and 26.8% respectively. Increasing external chloride concentration and w/c ratio can improve the chloride capacity of pure cement paste. Carbonation of cement paste will reduce the chloride capacity. Chloride binding do affect the durability of reinforced concrete in saline environment.