基金supported by High-tech 863 Program under the project of “Development of a 4 500 m deep manned submersible” (Project No. 2009AA093303)Fourth Term of “333 Engineering” Program of Jiangsu Province under the project of “Fatigue and fracture performance of domestically produced high strength titanium alloys for the 4 500 m deep manned pressure hull” (Project No.BRA2011116)
