Coherent sensing of a mechanical resonator with a single-spin qubit

Mechanical systems can be influenced by a wide variety of small forces, ranging from gravitational to optical, electrical, and magnetic. When mechanical resonators are scaled down to nanometer-scale dimensions, these forces can be harnessed to enable coupling to individual quantum systems. We demonstrate that the coherent evolution of a single electronic spin associated with a nitrogen vacancy center in diamond can be coupled to the motion of a magnetized mechanical resonator. Coherent manipulation of the spin is used to sense driven and Brownian motion of the resonator under ambient conditions with a precision below 6 picometers. With future improvements, this technique could be used to detect mechanical zero-point fluctuations, realize strong spin-phonon coupling at a single quantum level, and implement quantum spin transducers.     

畜禽矿物质微量元素添加剂的作用

本文论述了畜禽缺乏钙、磷、钠、氯和微量元素铁、铜、钴、硒、碘时引起的各种病症，矿物质微量元素对畜禽的生理作用，指出了此类添加剂的饲喂方法和正确的使用方法。     

中草药饲料添加剂的作用与开发

中草药饲料添加剂不但能发挥促进动物生长的作用,而且能克服化学添加剂引起的动物产品中药物、激素、微量元素的超标残留.本文简述了中草药饲料添加剂的作用和功效,分析了其研发现状及趋势.