She returned to Beijing on Sunday after visiting her husband, Mr. Zhang said. Ms. Liu could not be reached for comment.

In an interview last week, Ms. Liu said she had little expectation that her husband would win the prize but said that if he did, she hoped it might prompt the authorities to release him earlier. “As my friends have said, how can they keep a Nobel Peace Prize winner in Jinzhou Prison?” she said.

Few Chinese citizens seemed aware of the honor accorded Mr. Liu, even 24 hours after its announcement. “Never heard of him, but we also haven’t watched TV recently,” said Yang Guwen, dressed in a denim cowboy shirt, as he and his girlfriend walked beneath a huge television screen that hangs over one of the capital’s ritziest shopping malls.

Had he followed news reports, Mr. Yang would not have learned that a Chinese citizen had won one of the world’s most respected prizes. Except for the Global Times editorial and a brief Foreign Ministry condemnation posted on the Internet, Chinese newspapers and Web-based portals ignored the news. Anyone typing the words “Nobel Peace Prize” or “Liu Xiaobo” into Google found themselves facing a blank screen.

A veteran civil rights lawyer, Teng Biao, said he was on his way to meet a foreign journalist on Saturday when he was stopped by national security agents at the Beijing university where he teaches. “The officers say that the police have rigid orders from higher authorities that they must work resolutely to thwart celebratory activities to mark this event,” he said in a cellphone interview, having briefly stepped away from the agents to take a call. “They are keeping a strict eye on the most active people, in order to reduce its impact to the smallest degree possible.”

The activists who gathered for the celebratory meal on Friday night were no strangers to police surveillance. Earlier in the evening, they had met in a park with yellow ribbons pinned to their shirts and clear plastic sleeves — the kinds favored by conventioneers — slung around their necks. The sleeves carried two portraits of Mr. Liu: one dark and somber, the other brightly lighted and decidedly cheery.