BEIJING — China has commissioned the aircraft carrier that it bought incomplete in 1998, naming the ship Liaoning, after a province.

The move marks formal delivery of Liaoning to the Chinese navy by China Shipbuilding Industry Corp., the state company that fitted out the hull that the former Soviet Union had built in Ukraine. The work was done in Dalian, a city in Liaoning.

The ship underwent a year of sea trials before the acceptance ceremony on Sept. 25, which was attended by Hu Jintao, Communist Party chairman and national president, and Premier Wen Jiabao.

“The ceremony made China the 10th country around the world and the last among the five permanent members of the U.N. Security Council to have an aircraft carrier in active service,” state news agency Xinhua said.

Liaoning will continue to serve for scientific research purposes, as well as military training, says the Central Military Commission, without explaining what kind of scientific research could rank alongside the ship’s national security functions. Training will surely be the priority for the first few years of Liaoning’s service, as it is for the first carrier of any navy.

“The delivery and commission of the first carrier is a milestone in the history of the People’s Liberation Army and embodies a major achievement of China’s weaponry and equipment development, as well as its national defense modernization,” Wen said.

The name of the carrier, which the Soviet navy planned to call Varyag, has been the subject of much speculation in China. The choice of Liaoning is in line with China’s policy of naming ships with geographical titles. Chinese destroyers and frigates are named after cities. Submarines generally get numbers, not names, but NATO assigns the name of a dynasty to each class. The party likes orderly arrangements, so future carriers will probably also get provincial names.

A retired Chinese general wanted to call the carrier “Diaoyu,” after the disputed islands that Japan calls Senkaku. While that may seem provocative, there was a good precedent. South Korea and Japan have a dispute over the Liancourt Rocks, which the former calls Dokdo and the latter Takeshima. The South Korean navy’s largest assault ship is called Dokdo.