Preparation (physics) experienced in quantum mechanics. Preparation (physics) Generally, measuring instruments are meant to get the (pre-)existent value of a physical quantity of a system with as little change of, or interaction with the system as possible. — If a measuring instrument fixes a physical quantity of a physical system for further use (post-existent), then the measurement process is called preparation. For example, a graduated cylinder filled to a definite mark prepares a certain volume of the liquid for further use. Though preparation measures a physical quantity — at least by fixing it — it often destroys previous states of the physical
European Physical Journal D European Physical Journal D The European Physical Journal D: Atomic, Molecular, Optical and Plasma Physics is an academic journal recognized by the European Physical Society, presenting new and original research results. The main areas covered are: The range of topics covered in these areas is extensive, from Molecular Interaction and Reactivity to Spectroscopy and Thermodynamics of Clusters, from Atomic Optics to Bose-Einstein Condensation to Femtochemistry. The EPJ D arose from various predecessors: "Il Nuovo Cimento (Section D)", "Journal de Physique", and "Zeitschrift für Physik D". Prior to 1998, this journal was named "Zeitschrift für Physik D: Atoms, Molecules and Clusters".