Xuzhou Institute of Technology

About: Xuzhou Institute of Technology is a education organization based out in Xuzhou, China. It is known for research contribution in the topics: Catalysis & Adsorption. The organization has 1696 authors who have published 1521 publications receiving 13541 citations.

Study on plasma cleaning of the large-scale first mirror of the charge exchange recombination spectroscopy diagnostic on EAST

Abstract: In EAST, the reflectivity of charge exchange recombination spectroscopy (CXRS) FM was dramatically dropped down to 20% of the original value after the operation of two EAST experimental campaigns from 2014 to 2015, leading to degradation of the signal intensity of the CXRS diagnostic to an unacceptably low level. The radio frequency plasma cleaning of the CXRS FM with a dimension of 303 ×81 ×76 mm3 and a small curvature of 0.008 mm–1 was performed to remove deposits for recovering the reflectivity. After 168 h cleaning, the maximum specular reflectivity of the FM can reach 92% of the original value at 532 nm, making the cleaned CXRS FM eligible to be reused for the CXRS diagnostic in the 2016 EAST campaign. Dedicated tests of sputtering polished mirror samples were performed to explore the cleaning uniformity and possible damage to the mirror surface. The specular reflectivity did not show obvious dependence on locations along the surface with the same cleaning time. The measured surface roughness gradually increased with sputtering time. The reflectivity kept almost unchanged regardless of different sputtering time and locations, indicating negligible damage to the FM surface even for 100 h sputtering. The re-contaminated CXRS FM in the 2016 EAST campaign was firstly cleaned for 81 h, the least reflectivity recovery for areas with relatively thick deposits was only 40%. After continuing cleaning to 147 h, the re-deposition of the sputtered residual deposits on the FM surface was observed. In the future in situ cleaning of FMs of EAST and ITER, deposits should be removed timely when they are very thin taking into account very long cleaning time and presumable re-deposition for thick and non-uniform deposits.

Perturbation analysis for the Moore–Penrose metric generalized inverse of closed linear operators in Banach spaces

Abstract: In this paper, we characterize the perturbations of the Moore–Penrose metric generalized inverse of closed operator in Banach spaces. Under the condition R(δT)⊂R(T), N(T)⊂N(δT), respectively, we get some new results about upper-bound estimates of ‖T¯M‖ and ‖T¯M−TM‖.