He Zengyun

A dissipative time crystal is a phase of matter characterized by periodic oscillations over time, while a system is dissipating energy. In contrast with conventional time crystals, which can also occur in closed systems with no energy loss, dissipative time crystals are observed in open systems with energy freely flowing in and out of them.

COVID-19 is surging in China, but its elderly population are not getting their vaccine boosters. The government is trying to change that.

BEIJING — Chinese authorities are going door to door and paying people older than 60 to get vaccinated against covid-19. But even as cases surge, 64-year-old Li Liansheng said his friends are alarmed by stories of fevers, blood clots and other side effects. "When people hear about such incidents, they

BEIJING (AP) — Chinese authorities are going door to door and paying people older than 60 to get vaccinated against COVID-19. But even as cases surge , 64-year-old Li Liansheng said his friends are alarmed by stories of fevers, blood clots and other side effects.