Climate change fostered rise and fall of the Tibetan Empire during 600-800 AD.

During the 7-9th century, the Tibetan Empire constituted a superpower between the Tang Empire and Abbasid Caliphate: one that played significant roles in geopolitics in Asia during the Early Medieval Period. The factors which led to the rise and rapid decline of this powerful Empire, the only united historical regime on the Tibetan Plateau (TP), remain unclear. Sub-annual scale precipitation and decadal-scale temperature records of the central TP are presented, indicating that the height of this Empire coincided with a two-century long interval of uncharacteristically warm and humid climate.

Investigation of a Liquid-Phase Electrode for Micro-Electro-Discharge Machining.

Micro-electro-discharge machining (μEDM) plays a significant role in miniaturization. Complex electrode manufacturing and a high wear ratio are bottlenecks for μEDM and seriously restrict the manufacturing of microcomponents. To solve the electrode problems in traditional EDM, a µEDM method using liquid metal as the machining electrode was developed.