The phrase "are characterised by two" is correct and usable in written English.
It can be used to describe features or attributes that are defined by two specific elements or characteristics.
Example: "The species are characterised by two distinct color patterns that help in their identification."
Alternatives: "are defined by two" or "exhibit two characteristics".
Current policy analyses in the IS literature are characterised by two contrasting theoretical positions regarding the way in which both rationales are conceptually interrelated.
Mediterranean wetlands are characterised by two factors: (1) a remarkable seasonal fluctuation in the water table and (2) a long history of anthropisation.
Lay-ups are characterised by two parameters: (i) sequencing (or interply lay-up angle) ¯θ and (ii) in-plane anisotropy β, and can be mapped on to ¯θ β space.
Here, specific stacking sequences support the development of so called bistable laminates which are characterised by two distinct deformation states which can be converted by applying forces or bending moments.
Mental states are characterised by two main properties, subjectivity, otherwise known as privileged access, and intentionality.
In this example the set of leaves is (X={a,b,c,d,e,f,g,h,i}), whose elements are characterised by two properties: (P_1) and (P_2).
NPM1 mutations are characterised by four basepair insertions within the region corresponding to the C-terminus of the protein leading to its translocation out of the nucleus.
Sub-grid stresses are represented by a dynamic version of the Smagorinsky model and sub-grid species fluctuations are characterised by eight stochastic fields.
The wavefunctions obtained are characterised by four quantum numbers: n, m the azimuthal quantum number, and two parabolic quantum numbers n 1 and n 2. These quantum numbers satisfy the condition that n=n 1+n 2+|m|+1+n
The western Baikiaea woodlands of southern Africa are characterised by six tree species that represent most of the growing stock and can be appropriately described as Baikiaea Pterocarpus woodlands.
All of these GPCR structures are characterised by seven transmembrane helices (TMHs) and an eighth helix which lies approximately parallel to the intracellular membrane.
