XPS study of surface absorbed oxygen of ABO_3 mixed oxides

Perovskite-type complex oxides ABO3 （A=Sr, La; B=Mn, Fe, Co） were prepared by citric acid method. The degradation of water-solubilized dyes was carried out using the mixed oxides as photocatalyst. The surface absorbed oxygen was analyzed using X-ray photoelectron spectroscopy （XPS）. The results indicated that there was a relationship between the photocatalytic activity and the content of the surface absorbed oxygen. The higher the content of the surface absorbed oxygen was, the better the performance of the photocatalyst.

Tunable and multichannel terahertz perfect absorber due to Tamm surface plasmons with graphene

In this paper, we have shown that perfect absorption at terahertz frequencies can be achieved by using a composite structure where graphene is coated on one-dimensional photonic crystal(1 DPC) separated by a dielectric. Due to the excitation of optical Tamm states(OTSs) at the interface between the graphene and 1 DPC, a strong absorption phenomenon occurs induced by the coupling of the incident light and OTSs. Although the perfect absorption produced by a metal–distributed Bragg reflector structure has been researched extensively, it is generally at a fixed frequency and not tunable. Here, we show that the perfect absorption at terahertz frequency not only can be tuned to different frequencies but also exhibits a high absorption over a wide angle range. In addition,the absorption of the proposed structure is insensitive to the polarization, and multichannel absorption can berealized by controlling the thickness of the top layer.

Activity and characteristics of ＂Oxygen-enriched＂ highly reactive absorbent for simultaneous flue gas desulfurization and denitrification

An ＂Oxygen-enriched＂ highly reactive absor- bent was prepared by mixing fly ash, lime and a small quantity of KMnO4 for simultaneous desulfiarization and denitrification. Removal of SO2 and NO simultaneously was carried out using this absorbent in a flue gas circulating fluidized bed （CFB）. The highest simultaneous removal efficiency, 94.5% of SO2 and 64.2% of NO, was achieved under the optimal experiment conditions. Scanning Electron Microscope （SEM） and Accessory X-ray Energy Spectrometer （EDX） were used to observe the surface characteristics of fly ash, lime, ＂Oxygen-enriched＂ highly reactive absorbent and the spent absorbent. An ion chromatograph （IC） and chemical analysis methods were used to determine the contents of sulfate, sulfite, nitrate and nitrite in the spent absorbents, the results showed that sulfate and nitrite were the main products for desulfurization and denitrification respectively. The mechanism of removing SO2 and NO simultaneously was proposed based on the analysis results of SEM, EDX, IC and the chemical analysis methods.

RETRIEVAL OF QINGHAI-XIZANG SASWR WITH ERBE AND ISCCP DATA

In the context of 1985—1988 ERBE and 1984—1988 ISCCP planetary scale albedoes and total cloudiness in combination with Qinghai-Xizang actinometric measurements,investigation was performed of the climatic retrieval of surface absorbed shortwave radiation(SASWR)in the research highland.Evidence suggests that the method has given higher fitting accuracy with mean error of 9.8 W m^(-2),whereupon was calculated the monthly mean SASWR flux density at the gridpoints of 2.5°×2.5°resolution over 25—40°N,75—95°E and 63 stations alongside a set of the distribution maps prepared for its basic features.