After a disciplinary upsurge, organic chemistry is about to embark on an epoch-making transition at the turn of the century. At present when the discipline is o
<正>A LM-4B launch vehicle lifted off at 11:00 Beijing time on June 15 from the Jiuquan Satellite Launch Center with Huiyan,China’s first X-ray space astronomi
At the Second World Conference on Coal held recently in London,a consensus was reached on the principal and continuing role played by coal on the world market i
The Primulaceae is a large subcosmopolitan family of 22 genera and about 1,000 species with a wide diversity in morphological features as well as in ecological
Electrodynamic tethered deorbit technology is a novel way to remove abandoned spacecrafts like upper stages or unusable satellites. This paper investigates and