4.1 Diffusion in 1D

  4.1.1 Finite domain (bar), Both ends homogeneous BC
  4.1.2 Finite domain (bar), left end homogeneous, right end not
  4.1.3 Finite domain (bar), right end homogeneous, left end not
  4.1.4 Finite domain (bar), Periodic BC
  4.1.5 Finite domain (bar), Both ends nonhomogeneous BC
  4.1.6 Semi-infinite domain
  4.1.7 Infinite domain

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