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The development of environmentally friendly, simple process and low cost synthesis methods for preparing graphene nanosheets (GNs) has attracted global interest. In this work, a simple and efficient method to synthesize GNs deriving from coal-tar pitch has been proposed from both experimental and theoretical point of views. The XRD, TEM and Raman results demonstrate that precursor Al4C3 could provide a growth environment for the final product of GNs. Innovatively, we have unraveled the microscopic origin for the decomposition of Al4C3 based on density functional theory calculations. It is highlighted that the surface energies and the analysis of elastic constants indicate the fact that the chemical etching process in Al4C3 can happen, which is similar to the exfoliation of well-known transition metal carbides MXenes. Furthermore, different bond breaking mechanisms have been found in Al4C3 at applied tensile and shear strains from the electron localization functions and stress–strain results. Our study not only offers an efficient method to synthesize GNs, but also to unravel the microscopic mechanism of fabrication by theoretical calculations.

Currently, building energy consumption accounts for 30-45% of global energy consumption, and the energy flexibility of the building provides it with controllable potential. In view of the lack of existing research on the overall controllable ability of building energy system from upper energy supply system. This paper defines controllable ability of building energy system, and proposes a unified dynamic evaluation model. Firstly, the impact of each influencing factor on the controllable ability is quantified, including virtual energy storage, electrical appliances, HVAC system, CCHP system, and occupants’ demand response. Secondly, analytical method and optimization method are used to evaluate the controllable ability. Then, based on the division of initial states, a sequential recurrence method is proposed to realize the dynamic evaluation of controllable ability. Finally, a practical case is used to verify the effectiveness and practicability of this method.

Monolayers of III–VI group two-dimensional (2D) materials MX (M = Ga and In and X = S, Se, and Te) have attracted global interest for potential applications in electronic and photoelectric devices due to their attractive physical and chemical characteristics. However, a comprehensive understanding of the distinguished carrier mobility in MX monolayers is of great importance and not yet clear. Herein, using a Boltzmann transport equation (BTE) solver and first principles calculations, we have precisely revealed that the intrinsic mobility in MX monolayers is significantly limited by phonon scattering. Note that the longitudinal acoustic phonon mode and optic phonon modes and were found predominantly coupled with electrons, which strongly restrained the intrinsic mobility in the MX monolayers. Interestingly, apart from a moderate band gap, the GaSe and GaTe monolayers exhibit high electron mobility exceeding 103 cm2 V−1 s−1 and may serve as outstanding electron transport channels. We believe that our findings will shed light on the design and applications of MX monolayers and 2D materials in nanoscale electronic and photoelectric devices.

Combining with the fold line videometrics, a method for pose estimation based on monocular measurements is studied. The method to measure the inertial position of the Photometric transfer station and the Orthogonal Iterative Algorithm based on the image space collinearity error is summarized. Then, the mistake using the Singular Value Decomposition (SVD) to solve is described and then introduce the improving algorithm. Finally, the Simulation and actual experiment is done to verify the accuracy of pose estimation using the fold line videometrics. The results show that the precision can reach 1mm or less using a camera with the resolution of 1280 by 1024 pixels, in the condition of 4.5 meter capturing distance and a Leica TS30.