migration of ions
91SÈVES — L’eau, les substances nutritives, les déchets et les hormones sont, dans les plantes, généralement transportés d’un organe à un autre par deux courants: la sève brute qui, dans les vaisseaux, transporte les matériaux venant de l’absorption… …
92Base (chemistry) — For the term in genetics, see base (genetics) Acids and Bases Acid dissociation constant Acid base extraction Acid–base reaction Acid–base titration …
93duricrust — /door i krust , dyoor /, n. a hard crust that forms on or in soil in semiarid climates owing to cementation of soil particles. Cf. caliche, hardpan (defs. 1, 2). [ < L dur(us) hard + I + CRUST] * * * ▪ geology Introduction surface or near… …
94surface analysis — ▪ chemistry Introduction in analytical chemistry (chemistry), the study of that part of a solid that is in contact with a gas or a vacuum. When two phases of matter are in contact, they form an interface. The term surface is usually… …
95alkaline-earth metal — /al keuh luyn errth , lin /, Chem. any of the group of bivalent metals including barium, radium, strontium, calcium, and, usually, magnesium, the hydroxides of which are alkalis but less soluble than those of the alkali metals. [1900 05] * * * ▪… …
96digestive system, human — Introduction the system used in the human body for the process of digestion. The human digestive system consists primarily of the digestive tract (alimentary canal), or the series of structures and organs through which food and liquids pass… …
97Collision cascade — A classical molecular dynamics computer simulation of a collision cascade in Au induced by a 10 keV Au self recoil. This is a typical case of a collision cascade in the heat spike regime. Each small sphere illustrates the position of an atom, in… …
98PHYSIOLOGIE — Aristote avait nommé «physiologues» les philosophes grecs présocratiques qui avaient proposé une explication générale de la nature des choses par le recours à quelque élément fondamental (eau, air, feu) ou à quelque composition d’éléments. De là …
99anions — Ion I on ([imac] [o^]n), n. [Gr. io n, neut, of iw n, p. pr. of ie nai to go.] 1. (Elec. Chem.) an atom or goup of atoms (radical) carrying an electrical charge. It is contrasted with neutral atoms or molecules, and free radicals. Certain… …
100cations — Ion I on ([imac] [o^]n), n. [Gr. io n, neut, of iw n, p. pr. of ie nai to go.] 1. (Elec. Chem.) an atom or goup of atoms (radical) carrying an electrical charge. It is contrasted with neutral atoms or molecules, and free radicals. Certain… …
