line, 443 dosage in atmospheric chemistry, 443 dose, 443 dose equivalent, , 444 dose in radioanalytical chemistry , 444 dose of a substance , 444 dose-response and dose-effect relationships, 444 double escape peak, 445 double-beam spectrometer (for luminescence spectroscopy) , 445 double-focusing mass spectrograph, 445 double-focusing mass spectrometer, 445 double-layer current, 445 double-strand chain in polymers, 446 double-strand copolymer, 446 double-strand macromolecule, 446 double-strand polymer, 446 double-wavelength spectroscopy, 447 doublet state, 447 doubling time in biotechnology , 447 down-time in analysis, 447 downconversion, 447 downfield, 448 downstream in membrane processes , 448 downwash in atmospheric chemistry , 448 drift, 448 driving force (affinity) of a reaction, , 449 driving force (for electron transfer), 449 drop time in polarography , 449 droplet in atmospheric chemistry, 449 Drude–Nernst equation (for electrostriction), 450 drug, 450drug design, 450 dry bulb temperature in atmospheric chemistry , 450 drying agent, 451 drying control chemical additive, 451 dual fluorescence of systems or molecular species , 451 dual substituent-parameter equation, 451 dual-mode photochromism, 452 dust collector in atmospheric chemistry , 452 dust fall in atmospheric chemistry, 452 dust in atmospheric chemistry , 452 dye laser, 453 dynamic field(s) mass spectrometer, 453 dynamic membrane formation, 453 dynamic range of an analyser , 453 dynamic reaction path (DRP), 453 dynamic surface tension, 454 dynamic thermomechanometry, 454 dynamic viscosity, , 454 dyne, 454 dyotropic rearrangement, 454 dypnones, 455 η (eta or hapto) in inorganic nomenclature , 455