The crystalline structure of SrRuO3: Application of hybrid scheme to the density functionals revised for solids

The crystalline structure of ground-state orthorhombic SrRuO3 is reproduced by applying the hybrid density functional theory scheme to the functionals based on the revised generalized-gradient approximations for solidstate calculations. The amount of Hartree–Fock (HF) exchange energy is varied in the range of 5–20% in order to systematically ascertain the optimum value of HF mixing which in turn ensures the best correspondence to the experimental measurements. Such investigation allows one to expand the set of tools that could be used for the efficient theoretical modelling of, for example, only recently stabilized phases of SrRuO3, helping to resolve issues emerging for the experimentalists.

A Method of Lower S/N Signal Detection by Amplifier and Computer

A new detection method of weak signal mixed in strong noise is proposed. The method includes theory scheme, hardware and software. It detects and processes signal by using the instrument magnifying technology and single-chip microcomputer control. By means of virtual instrumentation simulation and display, this design provides effective methods to detect µA-level weak signal in piezoelectric infrared detector. Through the experiment of simulate low frequency weak signal detection, the system fully reveals its practicality and superiority in the field of lower S/N signal detection.