BEIJING, Dec. 19 -- The Chinese Academy of Engineering (CAE), one of the country's top academic institutions, announced on Thursday that 51 prominent scientists have been elected as academicians, bringing the number of CAE academicians to 807.

The average age of the newly elected academicians is 56.9, the CAE said on its website.

The eldest is 77-year-old Xu Qinan, chief designer of Jiaolong, China's first manned deep-sea submersible, which reached a record depth of 7,062 meters in the Pacific's Mariana Trench during a dive in June 2012. The youngest new member is 48 years old.

Forty-two, or about 82.4 percent, of the new academicians were 60 years old or younger, up from 70.4 percent in 2011.

The CAE started its biennial election of academicians in January.

The new academicians were elected from 560 candidates. Twenty-one of the newly elected are from higher learning institutions, 14 are from research institutes, 11 are from companies, and five are from administrative departments.

CAE academician is the highest national academic title in the field of engineering and is a lifelong honor. New members are added every two years, with a quota of no more than 60 for each election.

In addition, six scientists were elected foreign CAE academicians, among whom four were from the United States, one from Australia, and one from Denmark, bringing the number of foreign CAE academicians to 45.

In a letter to the newly elected academicians, the CAE put forward "eight tenets" for them to observe, calling on them to continue to make full use of their advantages in the engineering field "in a modest and discreet manner, rather than taking pride as an authoritative figure."

The CAE advised the new academicians to shun commercial advertisements, excessive concurrent posts and "excessively high or inappropriate material benefits."

The CAE also asked institutions the academicians are affiliated with to enable them to reserve their energy to use where it is needed most, rather than on unnecessary social engagements.