One-loop calculations in Lorentz-breaking theories and proper-time method

We discuss applications of the proper-time method in various minimal Lorentz violating modifications of QED and present new results obtained with its use. Explicitly we calculate the complete one-loop Heisenberg-Euler effective action involving all orders in $F_{\mu\nu}$, for two of the most studied minimal Lorentz-violating extensions of QED, the one characterized by the axial vector $b^{\mu}$ and the one involving the second-rank constant tensor $c^{\mu\nu}$.

Anısotropy Property of Dıfferent Types of Wood

The norm of elastic constant tensor and the norms of the irreducible parts of the elastic constants of different types of wood. The relation of the scalar parts norms and the other parts norms and the anisotropy of these woods is presented. The norm ratios are used as a criterion to present the anisotropy degree of the properties of these woods

Two Equivalent Reduction Methods of Dielectric Constant Tensor for Hexagonal Crystal System Materials

Hexagonal crystal system materials have very important applications in modern society. Dielectric constant tensor of hexagonal crystal system materials is simplified only by the formula in a hexagonal coordinate system, not by the formula often seen in current Chinese solid state physics textbooks. Meanwhile, the equivalence of hexagonal coordinate system and rectangular coordinate system is presented in the paper.