Summary The 2021 Mw7.4 Maduo earthquake occurred on the Jiangcuo fault within the Bayan Har block in eastern Tibet. It is a rather unique event, and attests that large earthquakes can occur in the interior of major tectonic blocks within the Tibetan plateau. By processing GPS data observed in the eastern Tibet region, we produce a dataset documenting three-dimensional coseismic displacements of the Maduo earthquake. Using the dataset to constrain a coseismic slip model, we find that the earthquake ruptured a nearly vertical fault about 170 km in length, with ∼90 per cent of the moment released in the shallow layer above 20 km depth. The maximum slip of ∼3.6 m occurred near the surface around a bend in the east segment of the fault. The overall seismic moment release is 1.82 × 1020 N·m, and equivalent to Mw7.4. Driven by the eastward extrusion of the Tibetan plateau, the deformation field in eastern Tibet is dominated by left-lateral shear, with the strikes of the tectonic faults rotating clockwise from west to east along with the shear stress orientation. This deformation pattern explains the mechanisms of earthquakes along block boundary faults, as well as the ones on faults within the blocks. The Jiangcuo fault is located ∼70 km south of the East Kunlun fault and could be connected to the Kunlun Mountain Pass fault to its WNW which ruptured during the 2001 Kokoxili earthquake, and a seismic gap of ∼240 km long between the two faults is worth special attention for its increased earthquake potential.

The polymerized small-molecule acceptors have attracted great attention for application as polymer acceptor in all-polymer solar cells recently. The modification of small molecule acceptor building block and the π-bridge linker is an effective strategy to improve the photovoltaic performance of the polymer acceptors. In this work, we synthesized a new polymer acceptor PG-IT2F which is a modification of the representative polymer acceptor PY-IT by replacing its upper linear alkyl side chains on the small molecule building block with branched alkyl chains and attaching difluorene substituents on its thiophene π-bridge linker. Through this synergistic optimization, PG-IT2F possesses more suitable phase separation, increased charge transportation, better exciton dissociation, lower bimolecular recombination, and longer charge transfer state lifetime than PY-IT in their polymer solar cells with PM6 as polymer donor. Therefore, the devices based on PM6:PG-IT2F demonstrated a high power conversion efficiency of 17.24%, which is one of the highest efficiency reported for the binary all polymer solar cells to date. This work indicates that the synergistic regulation of small molecule acceptor building block and π-bridge linker plays a key role in designing and developing highly efficient polymer acceptors.

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All-polymer solar cells (all-PSCs) possess distinguished advantages of excellent morphology stability, thermal stability, and mechanical flexibility. Tandem solar cells, by stacking two sub-cells, can absorb more photons in a wider wavelength range and can reduce thermal losses. However, limitation of polymer acceptors with suitable bandgaps hinders the development of tandem all-PSCs. Herein, highly efficient tandem all-PSCs are fabricated by employing two polymerized small molecular acceptors (PSMAs) of wide bandgap PIDT (1.66 eV) in the front cell and narrow bandgap PY-IT (1.4 eV) in the rear cell. The two sub-cells with the polymer donors of PM7 in front cell and PM6 in rear cell show high open circuit voltage ( V oc ) of 1.10 V for the front cell and 0.94 V for the rear cell. By rational device optimizations, the best power conversion efficiency of 17.87% is achieved for the tandem all-PSCs with high V oc of 2.00 V. 17.87% is one of the highest efficiency for the all-PSCs, and 2.00 V is one of the highest V oc for all the tandem organic solar cells. Moreover, the tandem all-PSCs show excellent thermal and light-soaking stability compared with their small-molecule counterparts. The results provide insight to the potential of bandgap tuning in PSMAs, and indicate that the tandem architecture is an effective strategy to boost performance of the all-PSCs.

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The structural mechanics analysis of the Portland cement concrete pavement (PCCP) is considerably complicated and distinctive. From the application viewpoint, the capabilities and characteristics of two typical professional finite element software products, named KENSLABS and EverFE, are analyzed. The similarities and differences between these two programs are compared. The comparisons focus on some key factors of modeling and solution strategies, such as element type, meshing, traffic load and temperature curling, boundary conditions, and contact conditions. Based on one specific case example, the two software products were conducted to demonstrate their main functions. The research results clarify the performance of the two software products for structural analysis of cement concrete pavement and indicate each application conditions from their respective features, which can provide valuable references for software users and program developers.