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In this work, a series of carbon microfiber (CMF)/FeS composites are synthesized by a molten-salt-guided synthetic strategy. The microstructures, electromagnetic (EM) response behaviors, and microwave absorption (MA) properties of these CMF/FeS composites have been systematically investigated. The results indicate that the prepared CMF/FeS exhibits effective MA performance, where its effective absorbing bandwidth (EAB) is 6.64 GHz (11.36–18 GHz). The check test shows that different molten salt (MS) systems influence the morphology, crystal planes and magnetic properties, and thus influence the MA performance of the composites. This research expands the application of molten salt strategy (MSS) in the MA field and explores the effects of different types of MS on the EM properties and MA performance, which supplies a reference for the application of MSS in the MA field. [Display omitted] [ABSTRACT FROM AUTHOR]

Electrical conductivity, interfacial polarization, and magnetic properties are key factors in designing efficient microwave absorbing (MA) materials. In this study, we report a one-step route to synthesize multicomponent C/MoS 2 /Co 9 S 8 composite via the molten salt strategy (MSS) and systematically investigate the MA performance of the C/MoS 2 /Co 9 S 8 composite. The excellent dielectric property is related to the conductive carbon network. In addition, magnetic Co 9 S 8 improves the impedance matching performance of the composite. Abundant heterointerfaces, such as C/MoS 2 , C/Co 9 S 8 and MoS 2 /Co 9 S 8 , exist in the C/MoS 2 /Co 9 S 8 composite, which leads to a great interface polarization effect. The synergy of these factors results in the effective MA performance of the C/MoS 2 /Co 9 S 8 composite. The results show that the EAB reached 6.0 GHz (12.0–18.0 GHz). In addition, the maximal MA performance of the C/MoS 2 /Co 9 S 8 reached – 62.1 dB. This research expands the application of MSS in MA materials, especially the preparation of multicomponent MA composites. [ABSTRACT FROM AUTHOR]

This report proposes a preparation route for the molten salt (MS)-assisted synthesis of cotton-like C/transition metal sulfide (TMD) composites. By using the mussel-inspired method, carbon derived from dopamine (DA) can be well combined with the TMDs synthesized by molten salt synthesis (MSS). The morphologies and structures, electromagnetic (EM) properties and MA performances were systematically analyzed. The results show that a series of synthesized cotton-like C/TMD composites exhibit efficient MA performance and are superior to many reports in the microwave absorption (MA) field. The best MA performance of cotton-like C/TMD composites can reach −63.49 dB, and the best effective absorption band (EAB) is 5.92 GHz. This work proposes a universal MS-assisted synthesis method for synthesizing composites with excellent MA performance and precise structure, which expands the application of MSS in the MA field and provides a reference for the synthesis of MA composites using the MS method combined with other methods. [ABSTRACT FROM AUTHOR]

• This is the first work to explore the application of metal substituted carbodiimides materials in MA field. This study fabricates novel nano composites (CNT/C 3 N 4 /MnNCN) via molten salt synthesis (MSS). This material reveals outstanding microwaves absorption (MA) performance, relatively thin thickness, as well as large-scale production. • The unique nanostructure, various interfaces and dielectric/magnetic loss mechanism are the main reasons for effective MA performance of CNT/C 3 N 4 /MnNCN. • This report not only explores the feasibility of the application of metal substituted carbodiimides in the MA field for the first time, but also serves references for the application of MSS in MA filed. Owing to their potential functional performance, metal-substituted carbodiimides of the form M(NCN) x have attracted the attention of scholars. However, the application of these new functional materials in microwave absorption (MA) has rarely been reported. In this study, carbon nanotube (CNT)/C 3 N 4 /MnNCN (CCM) was prepared via a facile molten salt strategy (MSS) to develop efficient microwave absorbing materials. The morphology, components, and MA properties of CCM were systematically investigated. The results show that synthesized CCM has an excellent MA performance. Specifically, the effective absorbing bandwidth (EAB) and optimal MA performance of CCM were 5.48 GHz (12.32–17.8 GHz) and −57.7 dB, respectively. The unique structure, special magnetic properties of MnNCN, and multiple loss mechanisms promote the MA properties of CCM. Therefore, this study explored the application of M(NCN) x in the field of MA for the first time and expanded the research on the MSS in the MA field. [Display omitted] [ABSTRACT FROM AUTHOR]

• The back contact point of the solar cell was optimized by adjusting the laser aperture ratio and the virtual-to-real ratio. • By reducing the area of the laser-opened busbar, the carrier recombination of the solar cell is reduced and the V oc of the cell is increased. • We found that laser drilling can cause an increase in the resistance of the back line. In this paper we investigate the effect of the opening ratio and the back layout design on the electrical performance of the solar cell. First, the point contact solar cells are optimized by adjusting the laser opening ratio and the virtual-to-real ratio on each grid line of back side. The experimental results show that the open-circuit voltage (V oc) of the solar cell increases as the opening ratio decreases. Analysis of the PL images also shows that the damage to the passivation layer causes the V oc to drop. By characterizing the resistance of the back line, we found that laser drilling can cause an increase in the resistance of the back line. This can also lead to the FF loss. Then, by reducing the contact area of the bus-bar at the backside, the carrier recombination of the solar cell is reduced and the V oc of the cell is increased, resulting in a 0.07% increase in cell efficiency. Finally, the simulation shows that the openings lead to an increase in the recombination current (J 01) at the base of the cell, which affects the efficiency of the cell. [ABSTRACT FROM AUTHOR]

• A new type of small-sized I-shaped UHPC beam was proposed. • The I-shaped UHPC beam was inner reinforced with steel plates/rods and surface bonded with BFRP sheets. • The flexural behavior of UHPC beams was tested under the four-point loading method. • The I-shaped UHPC beam has promising application prospects in extremely corrosive environments. A new type of small-sized I-shaped ultra-high-performance concrete (UHPC) beam was proposed and tested in this paper. The bottom flange of the I-beam was hybrid reinforced with an embedded steel plate and basalt fiber reinforced polymer (BFRP) sheets. The web was hybrid shear reinforced with embedded steel threaded rods and vertically surface bonded BFRP sheets. The flexural behavior was tested using the four-point loading method, the test parameters include the cross-sectional area of the steel plate, the containing or not of the threaded rods in the web, and the number of the surface bonded BFRP layer. Based on the test data, the calculation and analysis of the cracking, yielding, and ultimate loads of the UHPC beam were conducted. The results showed that the proposed new hybrid beam has excellent mechanical properties. The proposed hybrid reinforcement method can greatly increase the bearing capacity of the UHPC beam from 10.2 kN to 76.6 kN and can increase the ultimate mid-span displacement from a very small 0.52 mm to an astonishing 45.02 mm. Thanks to the ultra-high durability of BFRP and UHPC itself, it has ultra-high durability that ordinary I-steel beams do not have, which has promising application prospects in extremely corrosive environments. [ABSTRACT FROM AUTHOR]