Ancient genomic time transect unravels the population dynamics of Neolithic middle Yellow River farmers

In 1921,Swedish geologist Andersson and his Chinese colleagues carried out thefirst excavation of the Yangshaocun site in Sanmenxia City of central China’s Henan Province[1].Archaeologists reached a consensus that the relics unearthed in Yangshaocun were dated back to the Neolithic Age and described in archaeology as the“Yangshao culture”,named after the Yangshaocun site[2].The discovery of Yangshao culture in Yangshaocun marked the beginning of modern archaeology in China and overturned the claims that China has no Stone Age culture.

Exhaust process of cryogenic nitrogen gas from a cryogenic wind tunnel with an inclined exit

A new structural design for the vent stack with an inclined exit was proposed to reduce the settlement hazard of the cryogenic plume from a cryogenic wind tunnel;it extends the plume trajectory to increase the effective contact space and time for mixing between the plume gas and atmospheric air before the plume settles to the ground,contributing to more efficient energy consumption for heating.Reduced-scale experiments and numerical simulations of plume dispersion based on vertical and 30°-and 45°-inclined exits were conducted to study harm reduction and energy-saving potential.Analyses of the minimum temperature and minimum oxygen concentration of the plume near the ground indicate that the new exhaust design with an inclined exit clearly reduces the settlement hazard.Under windless conditions and without using a fan-ejector system,up to 15.9%of the heating energy used by the burner can be saved by adopting the new design.

Prospects of sea launches for Chinese cryogenic liquid-fueled medium-lift launch vehicles

This paper introduces the sea-launch technology of a cryogenic liquid-fueled medium-lift rocket.It first reviews the current state of sea launch technology,and then gives a brief introduction of China’s New Generation Medium-lift Launch Vehicle(NGMLV).The innovations in the NGMVL,such as responsive test and launch control,a H3 launch model,and unmanned operations,provide convenience for sea launches.Based on these innovations,this paper proposes a sea launch scheme,including the system configuration,test and launch processes,and an improved adaptive design for the rocket.Then,the launch platform is discussed in detail,which integrates the functions of sea transportation,assembly and test,as well as technical and launch areas.The layout and function divisions,fluid filling,gas supply and distribution systems,and lossless storage technology of LH2 are described in order.This breakthrough in sea launch technology will enable China to launch medium and large satellites and constellations‘both on land and sea’,especially into low-inclination Low-Earth Orbits(LEOs),and it allows China to remain competitive in the fast-paced space industry.