Jianwei Wei

Graphene coatings greatly improve the stability of FAPbI ₃ in the environment of H ₂ O and O ₂ , while improving the absorption efficiency of ultraviolet, visible and infrared light. Functional groups can further enhance this ability.

The topological architecture of polymer carriers is a critical determinant of their drug loading capacity and release characteristics. This study employed dissipative particle dynamics (DPD) simulations to systematically investigate the drug distribution and pH-responsive release behavior of three ABC-type polymer carriers with identical block compositions (where A is hydrophobic, B is pH-responsive, and C is hydrophilic) but distinct topologies: miktoarm star polymer, linear triblock copolymer, and star block copolymer. The simulation results revealed the fundamental differences in the drug distribution mechanism induced by the topological architecture of polymers. The miktoarm star polymer enables a unique "core-shell dual loading" mode, where drug molecules (doxorubicin, DOX) are simultaneously encapsulated within both the hydrophobic core and the pH-responsive middle layer. In contrast, within the micelles of linear and block-star copolymers, drug molecules are predominantly confined to the intermediate layer. Despite both the linear and star block copolymer systems exhibiting a "shell-loading" mode for drug distribution, the star block copolymers demonstrate a faster drug release under acidic conditions, whereas the linear block copolymers exhibit gradual drug release. Through the analysis of the interfacial electrostatic environment, we observed that a balanced ion distribution facilitates drug release in the star block copolymer system, whereas a counterion barrier arising from an overcharging effect impedes release in the linear block copolymer system. This study highlights the topological design as a robust strategy for precisely modulating both the spatial distribution and release behavior of therapeutic agents within nanocarriers.

DPD simulations are adopted to explore how topological architecture governs structure–property correlations of ABC-type polymer carriers, with distinct drug loading behaviors and release mechanisms observed among these delivery systems.

The self-assembly of miktoarm star polymers μ-A_i(B(D))_jC_k in a neutral solution and the pH-responsive behaviors of vesicles and spherical micelles in an acidic solution have been investigated by DPD simulation. The results show that the self-assembled morphologies can be regulated by the lengths of pH-responsive arm B and hydrophilic arm C, leading to the formation of vesicles, discoidal micelles, and spherical micelles in a neutral solution. The dynamic evolution pathways of vesicles and spherical micelles are categorized into three stages: nucleation, coalescence, and growth. Subsequently, the pH-responsive behaviors of vesicles and spherical micelles have been explored by tuning the protonation degree of pH-responsive arm B. The vesicles evolves from nanodisks to nanosheets, then to nanoribbons, as the protonation degree increases, corresponding to a decrease in pH value, while the spherical micelles undergoes a transition into worm-like micelles, nanosheets, and nanoribbons. Notably, the electrostatic interaction leads the counterions to form a regular hexagonal pattern in nanosheets, while an alternative distribution of charged beads has been observed in nanoribbons. Furthermore, the role of the electrostatic interaction in the morphological transition has been elucidated through the analysis of the distribution of positive and negative charges, as well as the electrostatic potential for associates.

The air-stable, low-toxicity double perovskite structure [ ] (X = Cl, Br and I) has attracted great attention due to its excellent potential in optoelectronic and photovoltaic applications. We used density functional theory to theoretically study the pressure response mechanism of double perovskite [ ]. The results show that pressure can effectively regulate the electronic structure and optical absorption properties of [ ]. When subjected to hydrostatic pressure ranging from 0 to 50 GPa, the bandgaps of [ ], [ ] and [ ] all exhibit a phenomenon of first decreasing and then increasing during the change. [ ] exhibits semimetallic properties when the valence band and conduction band begin to overlap under hydrostatic pressure of 2 GPa or higher. In addition, with increasing pressure, the optical absorption peak of [ ] shows a significant blue shift, and the absorption coefficient in the visible and near-infrared regions gradually increases. When a uniaxial pressure is applied to [ ] crystal, it significantly reduces in one direction and expands in the other two perpendicular directions. The structure changes from cubic phase to tetragonal phase. The optical absorption coefficient in the direction of pressure first increases and the others decrease.

The systematically studied about the doped Cs₂TiBr₆ with Si, Ge, Cl or I show that Cs₂Ti(Br_0.75I_0.25)₆ have the best optical performance. The possible direction of improving the optical properties of Cs₂TiBr₆ were shown by this work.

The Compton scattering process plays significant roles in atomic and molecular physics, condensed matter physics, nuclear physics and material science. It could provide useful information on the electromagnetic interaction between light and matter. Several aspects of many-body physics, such us electronic structures, electron momentum distributions, many-body interactions of bound electrons, etc., can be revealed by Compton scattering experiments. In this work, we give a review of ab initio calculation of Compton scattering process. Several approaches, including the free electron approximation (FEA), impulse approximation (IA), incoherent scattering function/incoherent scattering factor (ISF) and scattering matrix (SM) are focused on in this work. The main features and available ranges for these approaches are discussed. Furthermore, we also briefly introduce the databases and applications for Compton scattering.

A novel Michelson interferometric hydrogen sulphide sensor coated with copper/reduced graphene oxide (Cu/rGO) composite membrane is proposed and fabricated. A section of endlessly photonic crystal fibre (EPCF) was sandwiched in two single-mode fibres (SMFs). One SMF was spliced and tapered with EPCF; the other SMF was connected with the Faraday rotator mirror to construct the Michelson structure. The cladding of the EPCF was coated by the Cu/rGO-sensing membrane, which was prepared by the dip-coating method. The obtained Cu/rGO-sensing film has a length of 25.0 mm. The fabricated sensing membrane is characterised by the scanning electron microscopy, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and so on. Experimental results demonstrated that the Cu/rGO-sensing film has a 24.56-nm thickness with a compact and uniform appearance. The XPS and Raman spectra indicate that there are three elements (C, O, and Cu), which are consistent with the expected compositions of the Cu/rGO membrane. With the increase of concentration of hydrogen sulphide, the interference spectra appear red-shifted. The linearity of 0.97662 and the sensitivity of 13.23 pm/ppm are achieved. In addition, the dynamic response and recovery time of the sensor are approximately 70 and 88 s, respectively. The surface adsorption energies of the film are calculated by the density functional theory. The theoretical results are in good agreement with the experimental findings. This sensor has some key advantages of small size, simple structure, easy fabrication, and great applicability for detecting the trace hydrogen sulphide.