IN view of the considerable attention given to the secondary spectrum of hydrogen in recent investigations, it may be worth announcing that this spectrum has been extended photographically so far ...

IT is usually considered that molecular hydrogen does not have an infra-red rotation-vibration spectrum. However, such a spectrum may be expected as a forbidden transition made possible by the ...

Photovoltaics (PVs), devices that can convert sunlight into electrical power, are becoming increasingly widespread and more ...