Seismic performance of two-story subway station structures with different isolating systems

When the sliding bearing is fixed only at the top of the middle column of the underground structure,the cracks at the side end of the middle plate should be aggravated while the seismic damage of the mid-column should be alleviated.To enhance the seismic performance of the mid-plate,a new isolation design method has been mentioned while the elastic sliding bearings are set at the top of the mid-columns and between the side end of the mid-plate and the side wall at the same time.By establishing a nonlinear finite element analysis model for the static-dynamic coupling interaction system,the seismic response characteristics of the cast-in-place station structure without a sliding bearing have been analyzed and compared with those of the station structure with the sliding bearing fixed only at the top of the middle columns,and those of the station structure with sliding bearing be fixed between the mid-plate and the sidewall at the same time.The results show that the new isolation station structures suffer fewer earthquake damages at the mid-plate and mid-columns at the same time,which can improve the overall seismic performance of the subway station structure.

Combination Mechanism and Enhanced Visible-Light Photocatalytic Activity and Stability of CdS/g-C3N4 Heterojunctions

In this study,CdS/g-C_3N_4(CSCN) heterojunctions were in situ fabricated with a large amount of Cd S nanoparticles anchored on g-C_3N_4 nanosheets.A wet chemical method was developed for the first time to determine the actual content of Cd S in CSCN composites.X-ray diffraction(XRD),Fourier transform infrared spectra(FTIR),high-resolution transmission electron microscopy(HRTEM) and UV-vis diffuse reflectance spectra(DRS) were employed to characterize the composition,structure and optical property of CSCN composites.Based on the isoelectric point(IEP) analysis of g-C_3N_4,a conclusion was obtained on the combination mechanism between Cd S nanoparticles and g-C_3N_4 nanosheets.The photocatalytic activity of CSCN composites was much better than those of individual Cd S and g-C_3N_4 for the degradation of azo dye Methyl Orange(MO) by 40 min adsorption in the dark followed by 15 min photocatalysis under visible light irradiation.After 5 cycles,CSCN composites still maintained high reactive activity with the MO degradation efficiency of 93.8%,exhibiting good photocatalytic stability.The Cd2+concentration dissolved in the supernatant detected by atomic absorption spectroscopy(AAS) of CSCN composites was lower than that of pure Cd S,implying that the photocorrosion of Cd S could be suppressed via the combination with g-C_3N_4.Photoluminescence emission spectra(PL) results clearly revealed that the recombination of photogenerated electron-hole pairs in CSCN composites was effectively inhibited due to the formation of heterojunctions.Based on the band alignments of g-C_3N_4 and Cd S,the possible photocatalytic mechnism was discussed.