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
Letters in Mathematical Physics abstract or index "Letters in Mathematical Physics": Academic OneFile, Academic Search, Astrophysics Data System, Chemical Abstracts Service, Current Contents/Physical, Chemical and Earth Sciences, Current Index to Statistics, EBSCO, EI-Compendex, INIS Atomindex, Inspec, Mathematical Reviews, ProQuest, Science Citation Index, Scopus, Summon by Serial Solutions, and Zentralblatt MATH. According to the Journal Citation Reports, its 2011 impact factor is 1.819 and 2012 impact factor is 2.415. Letters in Mathematical Physics Letters in Mathematical Physics is a peer-reviewed scientific journal in mathematical physics published by Springer Science+Business Media. It publishes letters and longer research articles, occasionally also articles containing topical reviews. It is