What substances have this structure (two-dimensional structure such as sheets or strips, not to be confused with the lattice of graphene)?

Question

I have three questions:

1. What substances have this structure (two-dimensional structure such as sheets or strips, not to be confused with the lattice of graphene)?

2. Are these substances in nature or an abstraction?

3. Does anyone know of articles on the "simulation of thermal conductivity in two-dimensional harmonic/anharmonic ideal crystals with a triangular lattice" and "dependence of the thermal conductivity of the sample size in two-dimensional ideal crystals with a triangular lattice."

Explanation of question 3:

[*] The ideal crystal: a collection of interacting particles (atoms), characterized by the correct spatial arrangement - the simplest model.
[*] The description in the framework of classical mechanics.
[*] The particles are arranged in a perfect crystal lattice.
Possible boundary conditions:
[*] Limited to infinity (infinite number of particles);
[*] Periodic (a finite number of particles).
[*] Potential interactions between the particles.
[*] We consider only the motion of nuclei (neglect the electronic degrees of freedom).
[*] The dimension of the crystal: 2D
[*] Structure: simple and complex.
[*] Type of lattice: triangular
[*] Ingredients: multielement.
[*] The structure of interaction:  many.
[*] The nature of the interaction: Drivetrain, torque.
[*] Type of particle: mass point, rigid body gyrostat.
[*] Elasticity (ratio of elasticity): linear, non-linear.
[*] The strength (resistance strain, spall strength).
[*] Thermoelasticity (equation of state)
[*] The thermal conductivity (heat transfer equation).
[*] The internal friction (irreversible transition of mechanical energy into heat).
[*] High-energy oscillations (excitation correlation degrees of freedom).
[*] Two-dimensional crystals: the lattice of interacting particles - a model for the study of the general properties of  media.
[*] Harmonic dimensional crystal - dimensional crystal with a linear interaction between the particles. Possible types: simple harmonic one-dimensional crystal (all particles are the same, and communication), complex harmonic one-dimensional crystal (particle mass and / or stiffness of connections vary periodically along the crystal).
[*] The anharmonic dimensional crystal - dimensional crystal with nonlinear interaction between the particles. 

I have an articles on this subject, but only for a 1D crystal (shown below), and I need this information for 2D crystals with triangular lattice.

The thermal conductivity in one-dimensional crystals:

http://ptps.oxfordjournals.org/content/45/231.abstract?sid=59ff5cd6-c8c3-4e9d-9e4b-263cffb39a40

http://arxiv.org/pdf/0806.4224v1.pdf

http://link.springer.com/article/10.1007%2Fs10955-008-9487-1

http://scitation.aip.org/content/aip/journal/jmp/8/5/10.1063/1.1705319