Complete digital access to quality FT journalism with expert analysis from industry leaders. Pay a year upfront and save 20%.
There are two main types of smoke alarm tech, says Raman Chagger, principal consultant at BRE, the Building Research Establishment. Ionisation-based systems use a tiny amount of radioactive material to charge, or ionise, particles in the air which flow between two small plates. Should smoke interrupt that flow of charged particles, the alarm goes off.
，详情可参考搜狗输入法2026
arXivLabs is a framework that allows collaborators to develop and share new arXiv features directly on our website.
27 February 2026
Because I am deeply concerned about users losing their most sacred data.