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The high entropy alloys (HEAs) is a kind of innovative alloy design conception. However, seldom quantitative thermodynamics descriptions were reported in the past. In this paper, as a demonstration, the microstructures and thermodynamic properties of CoCrCuFeNi HEA were studied by combining experimental approaches with computational simulations. The CoCrCuFeNi alloy shows duplex FCC structure with Cu-lean and Cu-rich phase. With the increase of heat treatment temperature from 773 K to 1273 K, the predicted total configurational entropy changes from 6.13 to 7.83 J·mol−1·K−1, which is far less than the common-believed Boltzmann's hypothesis value (13.38 J·mol−1·K−1) due to the ordering behavior of element occupying on the sublattices. Cu atoms tend to enrich in liquid phase, which segregates as interdendritic microstructure during solidification process. The experimental results are highly consistent with the calculated results.

We present new photometric observations of the short period binary DY CVn. By using the Wilson-Devinney code of 2013 version, we found that DY CVn is a shallow contact binary ( f = 13.2 % ) with a high mass ratio of q = 1.251 . It is a W-subtype contact system where the more massive component is about 113 K cooler than the less massive one. From 44 available CCD times of light minimum collected from the references and 3 new ones in the present paper, the variation of the orbital period is studied. It is found that the O − C diagram shows a cyclic variation, and the most plausible explanation for this cyclic change is the light-travel time effect via a third body, since an outer third companion could play an important role for its formation by removing angular momentum from the central binary.

The first four-color light curves of V868 Mon in the $B$ $V$ $R_c$ and $I_c$ bands are presented and analyzed by using the Wilson-Devinney method of the 2013 version. It is discovered that V868 Mon is an A-subtype contact binary (f=$58.9\,\%$) with a large temperature difference of 916$K$ between the two components. Using the eight new times of light minimum determined by the authors together with those collected from literatures, the authors found that the general trend of the observed-calculate ($O$-$C$) curve shows a upward parabolic variation that corresponds to a long-term increase in the orbital period at a rate of $dP/dt=9.38\times{10^{-7}}day\cdot year^{-1}$. The continuous increase may be caused by a mass transfer from the less massive component to the more massive one.