ABSTRACT The interaction between impinging magnetized solar wind and Martian crustal fields produces complexly distributed magnetic topologies in the dayside magnetosphere. This study focused on obtaining the distribution of Martian dayside magnetic topology and the structures of the cross-terminator magnetic loops. A 3D multispecies magnetohydrodynamic model was employed to simulate the interactions between Mars and solar winds, and a 110° spherical harmonic model was used to calculate the crustal fields. We randomly extracted more than 1000 magnetic field lines from the near-Mars region of the model results. These results indicate the existence of large-scale closed fields and high-inclination-angle open fields in the Southern hemisphere, exerting their influence even above the height of the ionopause, resulting in a complex relationship between plasma motion and magnetic topology distribution. In contrast, the plasma motion patterns in the Northern hemisphere are similar to those observed in unmagnetized planets. Furthermore, the model results show two types of cross-terminator magnetic loop. Small-scale cross-terminator magnetic loops connect the local atmosphere on the dayside and nightside, whereas many large-scale magnetic loops cross the centre–tail region and extend more than 2RM downstream of Mars, especially in the Southern hemisphere. Finally, the clock angle distribution shows magnetic field distortion at 1000 km altitude. This study provides a clearer and more detailed description of the Martian dayside magnetic topology and the structures of the cross-terminator magnetic loops.
The development of organic solar cells (OSCs) with thick active layers is of crucial importance for the roll-to-roll printing of large-area solar panels. Unfortunately, increasing the active layer thickness usually results in a significant reduction in efficiency. Herein, we fabricated efficient thick-film OSCs with an active layer consisting of one polymer donor and two non-fullerene acceptors. The two acceptors were found to possess enlarged exciton diffusion length in the mixed phase, which is beneficial to exciton generation and dissociation. Additionally, layer by layer approach was employed to optimize the vertical phase separation. Benefiting from the synergetic effects of enlarged exciton diffusion length and graded vertical phase separation, an efficiency of 17.31% (certified value of 16.9%) is obtained for the 300 nm-thick OSC, with a short-circuit current density of 28.36 mA cm-2, and a high fill factor of 73.0%. Moreover, the device with an active layer thickness of 500 nm also shows an efficiency of 15.21%. This work provides valuable insights into the fabrication of OSCs with thick active layers.
A series of novel non-volatile DTC solid additives with a long flexible alkyl chain were designed and synthesized to improve the efficiency, photostability and mechanical durability of all-polymer solar cells (all-PSCs).
We synthesized three fluorinated non-fullerene acceptors, BTP-F, Y6-F and L8-BO-F, and further used them as the third components to fabricate ternary organic solar cells. The PM6:BTP-eC9:BTP-F ternary device yielded a high efficiency of 18.45%.
The directions of Martian magnetic field, which depends on the interaction between the crustal magnetic field and the time-various interplanetary magnetic field (IMF), is in a state of disorder and plays a significant role in ions vertical transport, such as ions upwelling and precipitation. In general, vertical diffusion transport of ionospheric plasma tends to be promoted around vertical magnetic field regions but be suppressed around horizontal magnetic field area. However, the mechanism behind this phenomenon is not clear to date. Based on three-dimensional multi-fluid Hall magneto-hydrodynamic (MHD) equations in conjunction with an equivalent source dipole (ESD) model, we investigated mechanism behind the control of vertical transport by different magnetic field directions in the Martian ionosphere. Numerical results showed that the same direction of interplanetary magnetic field with ESD results in the formation of mini-magnetosphere to protect the ionosphere, which reflected in higher density distributions comparing to the no-ESD case due to joint effects of thermal pressure increasing and plasma vertical transport. At low altitude of ionosphere, O+ ion inward transport (precipitation) tends to be inhibited particularly around horizontal magnetic field, with high contribution from the motional electric force. In addition, at high altitude, O+ outward transport (upwelling) is likely to be facilitated over vertical-field areas in significant part controlled by the ambipolar electric force, whereas it is likely to be inhibited in horizontal-field region, contributed mainly from the Hall electric force. These results will enrich our understanding of mechanisms behind the control of ions vertical transport by magnetic field directions.
A series of polymer acceptors have been synthesized. The optical and electronic properties of the copolymers can be well-tuned via a random copolymerization strategy. The best-performing PY-82-based binary device produces a record-high efficiency of 17.15%.
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