Search

Mobile passive differential optical absorption spectroscopy measurements of SO2 and NO2 were performed in the Guangzhou eastern area (GEA) during the Guangzhou Asian Games 2010 from November 2010 to December 2010. The observations were carried out between 10:00 to 13:00 (local time, i.e., during daylight). Spatial and temporal distributions of SO2 and NO2 in this area were obtained and emission sources were determined using wind field data. The NO2 vertical column densities were found to agree with Ozone Monitoring Instrument values. The correlation coefficient (referred to as R2) was 0.88 after cloud filtering within a specific ground pixel. During the Guangzhou Asian Games and Asian Paralympics (Para) Games, the SO2 and NOx emissions in the area were quantified using averaged wind speed and wind direction. For times outside the games the average SO2 emission was estimated to be 9.50 ± 0.90 tons per hour and the average NOx emission was estimated to be 5.87 ± 3.46 tons per hour. During the phases of the Asian and Asian Para Games, the SO2 and NOx emissions were reduced by 53.50% and 43.50%, respectively, compared to the usual condition. We also investigated the influence of GEA on Guangzhou University Town, the main venue located northwest of the GEA, and found that SO2 concentrations here were about tripled by emissions from the GEA.

Invertebrate Survival Journal, Vol 15 No 1 (2018)

Astaxanthin (AST) is a beneficial dietary supplement in shrimp farming. However, the different effects of synthetic AST (S-Ast) and natural AST (N-Ast) on the postlarvae is unclear. These effects were compared by supplementation with a gradient of AST (0, 50, 70, 90, 140 ppm) for 35 days. Growth parameters including weight and length gain, carotenoid content, AST content and isomer composition, antioxidant capacity (superoxide dismutase, catalase, glutathione peroxidase), survival rate and mRNA expression levels for antioxidant enzymes in Litopenaeus vannamei postlarvae were measured. The results indicated that postlarvae given N-Ast had significantly higher growth performance and AST content. Although there were different ratios of AST optical isomers in the diets, there was a similar optical isomer content in juvenile shrimp. The cis/trans AST ratio and antioxidant enzyme (SOD and GPx) activities in N-Ast90 were the highest among all groups. Cumulative mortality in N-Ast90, N-Ast140 and S-Ast70 were significantly lower than in the control and N-AST50. The mRNA expression levels for the antioxidant enzymes (cMnSOD and GPx) also increased for N-Ast90-fed shrimp under stress conditions. These results suggest that an epimerase may exist in vivo and that an appropriate level of botanical AST in diets was approximately 90 ppm for L. vannamei postlarvae., Invertebrate Survival Journal, Vol 15 No 1 (2018)

This paper explores a method to correct the image movement model of an off-axis Three-mirror Anastigmat (TMA) optical system to obtain higher mapping accuracy. Two kinds of line-array Off-axis TMA mapping cameras were modeled and the calculation formulas of image motion speeds and drift angles for the oblique-view camera and the nadir-view camera were deduced by considering earth curvature. By taking the off-axis TMA aerospace mapping camera with an intersection angle of 25 for an example, the influences of image motion speed matching remains and drift angle remains on the image quality of off-axis TMA aerospace mapping camera were analyzed at the oblique-view camera adjusted with the row transfer periods and their drift angles. Results indicate if more 5 TDI stages are used, the oblique-view camera and the nadir-view camera under a constraint of 5% MTF reduction should adjust their row transfer periods respectively; if drift angle of the oblique-view camera is adjusted according to the nadir-view camera, TDI stages should be no more than 71. However, If drift angles are adjusted by giving attention to the oblique-view camera and the nadir-view camera, the imaging quality for the both cameras has no essential influence at a TDI stage of 96.

The scroll imaging of a space camera can improve its temporal resolution. However, the space camera shows different image motion speeds and drift angles at different positions of field of view in the scroll imaging because of the earth ellipsoid and varied scroll angles. To overcome the problem, the formulas of image motion speeds and drift angles at different positions of field of view were deduced for the scroll imaging based on earth ellipsoid. By taking a high resolution space camera carried on a stereoscopic mapping satellite for an example, the influence of row transfer periods and drift angles adjusting uniformly and individually on Modulation Transfer Function(MTF) was analyzed. Analysis results and on-orbit testing experiments under a constraint of 5% drop for the MTF indicate that the row transfer periods should be adjusted individually if the integral stages are more than 22 in scroll imaging with scroll angle of 10. In comparison to adjusting row transfer periods uniformly, the drop of MTF along the track direction would be cut down from 10.28% to 0.11% by adjusting row transfer periods individually. If integral stages are fixed to 16, the scroll angle by adjusting row transfer periods uniformly should not be over 13.2.