139922 EI energy intake 891 139917 EI electron impact 285 139914 Ei efficiency 3 139924 ei electron-ion collision frequency nu 2 139920 ei equilibrative NBMPR-insensitive 2 139915 ei either inward efficiency 1 139916 ei elastoinertial number N 1 139925 ei encapsidation initiation site 1 139923 ei energy relaxation coupling constants g 1 139921 ei equilibrative, dipyridamole-sensitive 1 139918 ei es and the NBMPR-insensitive 1 139919 ei expression for nu 1 139926 ei eye velocity 1 139913 ei eye velocity profile 1