High-temperature measurements above 1000 °C are critical in harsh environments such as aerospace, metallurgy, fossil fuel, and power production. Fiber-optic high-temperature sensors are gradually replacing traditional electronic sensors due to their small size, resistance to electromagnetic interference, remote detection, multiplexing, and distributed measurement advantages. This paper reviews the sensing principle, structural design, and temperature measurement performance of fiber-optic high-temperature sensors, as well as recent significant progress in the transition of sensing solutions from glass to crystal fiber. Finally, future prospects and challenges in developing fiber-optic high-temperature sensors are also discussed.

Poly (vinylidene fluoride) (PVDF) is a kind of semicrystalline organic polymer piezoelectric material. Adopting processes such as melting crystallization and solution casting, and undergoing post-treatment processes such as annealing, stretching, and polarization, PVDF films with high crystallinity and high piezoelectric response level can be realized. As a polymer material, PVDF shows excellent mechanical properties, chemical stability and biocompatibility, and is light in weight, easily prepared, which can be designed into miniaturized, chip-shaped and integrated devices. It has a wide range of applications in self-powered equipment such as sensors, nanogenerators and currently is a research hotspot for use as flexible wearable or implantable materials. This article mainly introduces the crystal structures, piezoelectric properties and their applications in flexible piezoelectric devices of PVDF materials.

A long list of main group and transition metals, even some lanthanides, have been examined based on first principles studies, to search for potential p-type dopants for β-Ga₂O₃.

Five coordination polymers (CPs) with distinct structures, namely, [Cu(H₂tptc)(1,4-bidb)]_n (1), {[Co₂(tptc)(1,3,5-tib)(H₂O)]·7H₂O}_n (2), {[Ni(tptc)_0.5(1,3-bimb)]·H₂O}_n (3), {[Zn(qptc)_0.5(1,4-bimb)]·3H₂O}_n (4), and {[Zn(qptc)_0.5(1,3-bimb)]·H₂O}_n (5) (H₄tptc = terphenyl-3,3′′,5,5′′-tetracarboxylic acid, H₄qptc = quaterphenyl-3,3′′′,5,5′′′-tetracarboxylic acid, 1,4-bidb = 1,4-bis(1-imidazol-yl)-2,5-dimethyl benzene, 1,3,5-tib = 1,3,5-tris(1-imidazol-yl)benzene, 1,3-bimb = 1,3-bis(imidazol-1-ylmethyl)benzene, and 1,4-bimb = 1,4-bis(imidazol-1-ylmethyl)benzene), have been synthesized through a mixed ligand strategy. Complex 1 features a new 3D (4,6)-connected net with a Schläfli symbol of (4²·6⁴)(4²·6⁸·7·8⁴). Complex 2 displays a 3D 2-fold interpenetrated framework with an unprecedented (3,3,4,4)-connected (6·8²)₂(6²·8³·10)(6²·8⁴) topology. Complex 3 exhibits a (3²·6²·7²)-kgm layer featuring a 2D + 2D → 3D packing supramolecular structure interweaved through [Ni(1,3-bimb)] lock knots. Complex 4 shows an unprecedented 3D (4,4)-connected 8⁶ net. Complex 5 is also a 2D + 2D → 3D supramolecular structure featuring kgm sheets hinged together through [Zn(1,3-bimb)] lock knots. In addition, the luminescence properties of 4 and 5 have been investigated. Moreover, complexes 1–3 show relatively good photocatalytic activities for methylene blue (MB) dye degradation in aqueous solution under UV light.

New artificial in-plane heterojunctions based on two-dimensional transition metal dichalcogenides fabricated in recent reports are considered able to offer great scope for applications. Here, we study by first principles calculations the adsorption of CO, H₂O, NH₃, NO, and NO₂ gas molecules on the MoS₂/WS₂ heterojunction. We have determined the optimal adsorption positions and the adsorption strength, which is driven by charge transfer between the molecules and the heterojunction. Except NH₃, which performs as the charge donor, all the other studied molecules act as charge acceptors to the heterojunction. The charge transfer mechanism has been discussed by analyzing the electronic structure of the molecules and the heterojunction. Further calculations show that the molecule adsorption significantly affects the electronic transport properties of the heterojunction. Both the rectification behavior and the value of the passing current can be altered by adsorption, and such sensitivity to adsorption makes the heterojunction a superior gas sensor that promises wide-ranging applications.