In this paper,the performance characteristics of ASTM A790 S31803 and ASTM A182 F51 duplex stainless steel were introduced,and the weldabilities were analyzed. The welding repair procedures of thick wall duplex stainl...In this paper,the performance characteristics of ASTM A790 S31803 and ASTM A182 F51 duplex stainless steel were introduced,and the weldabilities were analyzed. The welding repair procedures of thick wall duplex stainless steel were developed by welding procedure qualification. Research shows that the repair welding has less effect on mechanical properties of welded joint, and great influence on phase proportions and pitting corrosion resistance. The test results meet the requirements of project specifications. The repair welding procedure can be used in project,and only one time repair shall be used.展开更多
This paper proposed a method to retrieve the land surface reflectance from the HJ-1A/B CCD data. The aerosol optical depth（AOD）, the most important factor affecting the atmospheric correction of CCD images at all ba...This paper proposed a method to retrieve the land surface reflectance from the HJ-1A/B CCD data. The aerosol optical depth（AOD）, the most important factor affecting the atmospheric correction of CCD images at all bands, is proposed to retrieve from the CCD imagery by the approach of dense dark vegetation（DDV） method. A look-up table in terms of the transmittances, the path radiances and the atmospheric spherical albedo as functions of the AOD was established for a variety of sun-sensor geometry and aerosol loadings. The atmospheric correction is then achieved with the look-up table and the MODIS surface reflectance output（MOD09） as the priori datasets. Based on the retrieved AOD and the look-up table of atmospheric correction coefficients, the land surface reflectance was retrieved for the HJ-1A/B data according to the atmospheric radiative transfer equation. Some in-situ measurement Data for Yanzhou of Shandong province in East China and MODIS land surface reflectance products MOD09 are used to preliminarily validate the proposed method. The results show that the proposed method can remove effectively the atmospheric contributions, and the overall accuracy of the retrieval land surface reflectance can be improved substantially.展开更多
文摘In this paper,the performance characteristics of ASTM A790 S31803 and ASTM A182 F51 duplex stainless steel were introduced,and the weldabilities were analyzed. The welding repair procedures of thick wall duplex stainless steel were developed by welding procedure qualification. Research shows that the repair welding has less effect on mechanical properties of welded joint, and great influence on phase proportions and pitting corrosion resistance. The test results meet the requirements of project specifications. The repair welding procedure can be used in project,and only one time repair shall be used.
基金National High Technology Research and Development Program of China,No.2012AA12A302
文摘This paper proposed a method to retrieve the land surface reflectance from the HJ-1A/B CCD data. The aerosol optical depth（AOD）, the most important factor affecting the atmospheric correction of CCD images at all bands, is proposed to retrieve from the CCD imagery by the approach of dense dark vegetation（DDV） method. A look-up table in terms of the transmittances, the path radiances and the atmospheric spherical albedo as functions of the AOD was established for a variety of sun-sensor geometry and aerosol loadings. The atmospheric correction is then achieved with the look-up table and the MODIS surface reflectance output（MOD09） as the priori datasets. Based on the retrieved AOD and the look-up table of atmospheric correction coefficients, the land surface reflectance was retrieved for the HJ-1A/B data according to the atmospheric radiative transfer equation. Some in-situ measurement Data for Yanzhou of Shandong province in East China and MODIS land surface reflectance products MOD09 are used to preliminarily validate the proposed method. The results show that the proposed method can remove effectively the atmospheric contributions, and the overall accuracy of the retrieval land surface reflectance can be improved substantially.
