The following information is missing from the Funding section: "The work was supported by National Natural Science Foundation of China (No. 31302181), Key R & D program of Shandong Province (2015GSF115013), Shandong Provincial Natural Science Foundation, China (No. ZR2013CM026), Science and Technology Development Plan of Yantai (No. 2013ZZ357), and Enterprise project (No. 2013HX007)."