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With the increasing demand for resource consumption, the mining depths gradually increase, resulting in increases of temperature at tens or even hundreds of degrees. High temperature could damage to interior structures and alter the mechanical properties of rock mass. Therefore, studying the effects of temperature on dynamic mechanical properties and failure behaviors are of great significance for deep resources exploitation. In this study, to study the effects of high temperature treatment on the strength and failure behavior of typical sandstones, specimens were prepared and heated to different degrees. The longitudinal wave velocity, volume, and density of specimens before and after high-temperature treatment were examined. Then, the Thomas Hopkinson (SHPB) test was conducted on specimens with different air pressures and the dynamic stress-strain curve, peak stress, peak strain, and other dynamic characteristics were obtained. The variations regulations and failure behavior of sandstone under the effects of high-temperature treatments and different impact loads were analyzed and discussed from the aspects of stress-strain, peak strength, and peak strain. It was observed that with the increase of heating temperature, the average density, average wave velocity, peak strength, and average elastic modulus of the sandstone specimens all showed a decreasing trend and the highest decreasing rated occurred at the temperature between 600 °C and 800 °C. The obtained results provided a certain theoretical basis for deep mine exploitation, especially for mines with high temperature.

The development of two-dimensional (2D) lateral heterostructures (LHs) with the powerful tunability of electronic properties will be of great realistic significance for next-generation device applications. Herein, we report the novel 2D MoX2 and MoX2H2 (X = As or Sb) monolayer materials with excellent stability. Using first-principles calculations, we demonstrated that 2D MoX2 layers possess the metallic characteristic while the full surface hydrogenation effect would play a role in stabilizing the 2D lattices and lead to band gap openings of 0.83 and 0.50 eV for the 2D MoAs2H2 and MoSb2H2, respectively. In addition, our results suggest that the 2D MoAs2H2 and MoSb2H2 can serve as the ‘building blocks’ to construct the seamless LHs exhibiting excellent thermal and dynamical stability. The obtained nL-MoAsSb LHs enable the fully tunable band gap engineering behavior with linear tendency as a function of the width of the in-plane components. The phase transition from direct to in-direct band gap was also confirmed in the LHs as the crucial value of n = 3. In view of the type-II band alignment and efficient carrier separation in nL-MoAsSb, the predicted MoX2H2 and nL-MoAsSb LHs not only highlight the promising candidates for 2D pristine materials, but also paves the way for the realization of practical integrating device applications.

It is well known that the interactions of p53 with murine double minute 2 and murine double minute X, namely MDM2 and MDMX, have been significant targets of efficient anti-cancer drug design. In this study, molecular dynamics (MD) simulations, principal component (PC) analysis and binding free energy calculations are combined to recognize binding selectivity of three ligands to MDM2 and MDMX. The binding free energies were estimated by using molecular mechanics generalized Born surface area (MM-GBSA) method and the obtained results display that the increase in the binding enthalpy of three ligands to MDM2 relative to MDMX mainly drives the binding selectivity of them toward MDM2 and MDMX. The information obtained from PC analysis shows that the associations of ligands exert important impacts on internal dynamics of MDM2 and MDMX. Meanwhile, the calculations of residue-based free energy decomposition not only identify the hot interaction spots of ligands with MDM2 and MDMX, but also show the residues (L54, M53), (Y67, Y66), (V93, V92), (H96, P95), (I99, I98) and (Y100, Y99) in (MDM2, MDMX) are responsible for most contributions to the binding selectivity of three ligands toward MDM2 and MDMX. It is believed that this work can provide useful information for design of highly selective and dual inhibitors targeting MDM2 and MDMX.Communicated by Ramaswamy H. Sarma.