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Lead-free organic–inorganic hybrid bismuth halides have been recognized as promising alternatives to lead-based perovskites for low-toxic and environmentally-friendly optoelectronic applications. These materials showcase unique optoelectronic properties, ascribed to their low-dimensional electronic structures, such as a long carrier lifetime, a strong quantum-well effect, self-trapped states, and good stability. However, there is still a lack of understanding of the structure dependency of these properties. Investigations of hybrid bismuth halides are thus highly urgent in the pursuit of developing functional optoelectronic devices utilizing these properties. Herein, we report a new one-dimensional (1D) polymeric organic–inorganic hybrid bismuth halide, PDABiI5 (PDA = 1,3-propane diammonium), which forms single crystals of centimeter size with a narrow optical bandgap of 1.77 eV. Interestingly, a reversible moisture-induced dimensional transformation was observed on 1D PDABiI5 through its conversion into 0D dimeric (PDA)2Bi2I10·2H2O, coming with a significant bandgap widening and photoluminescence shifts. This transformation is attributed to water molecules forming hydrogen bonds with the ammonium groups, promoting the deformation of Bi–I bonds from [BiI52−]n chains to edge-sharing [Bi2I10]4− dimers. This phenomenon presents exciting prospects for environmentally responsive device applications. Furthermore, optoelectronic characterizations demonstrated a long carrier lifetime exceeding 2 μs, a defect density of 1.49 × 1010 cm−3 and a high μτ product of 4.06 × 10−4 cm2 V−1. This work provides insights into the unique properties of PDABiI5 and (PDA)2Bi2I10·2H2O and their structure–property correlation, and offers promising avenues for the development of eco-friendly and functional optoelectronic devices. [ABSTRACT FROM AUTHOR]

The purpose of this study is to address the problem of reconstructing damaged styrene–butadiene–styrene (SBS) molecular structures in order to facilitate the effective recycling of aged SBS-modified asphalt (SBSMA). Traditional experimental methods face challenges when attempting to investigate the reconstruction process and reaction mechanism of aged SBS molecules. To explore the reaction mechanism of aged SBSMA with active rejuvenators and to promote the recycling of aged SBSMA, this study employs molecular dynamics and quantum chemistry to investigate the reconstruction process of the damaged SBS molecular structure using two reactive compounds, namely, methylene diphenyl diisocyanate (MDI) and toluene diisocyanate (TDI), from a molecular perspective. The results showed that the carbon–carbon double bonds in the SBS molecules are susceptible to oxidation, leading to the formation of hydroxyl and carboxyl groups. The reaction between the hydroxyl groups in aged SBS and TDI can spontaneously proceed, while the reaction between the carboxyl groups and MDI can also spontaneously proceed. When the proportion of hydroxyl groups in aged SBS molecules is higher, TDI can be the preferred choice for reconstructing aged SBS molecules. Conversely, when the aged SBS molecules contain more carboxyl groups, MDI can be selected as the better reactive compound. By reconnecting the aged SBS molecules, the need for new SBSMA can be reduced, leading to lower demand for original resources, extended material service life, reduced waste generation, and effective resource recycling. This study provides a new method to explore the problem of SBS molecular structure damage reconstruction and offers a possible mechanism explanation of reaction between aged SBS molecules and reactive compounds. These findings are expected to promote the sustainable development and environmental applications of SBSMA. [ABSTRACT FROM AUTHOR]

Developing an effective and reliable integrated drought index is crucial for tracking and identifying droughts. The study employs game theory to create a spatially variable weight drought index (game-theory-based drought index, GTDI) by combining two single-type indices: an agricultural drought index (standardized soil moisture index, SSMI), which implies drought hazard-bearing conditions, and a meteorological drought index (standardized precipitation evapotranspiration index, SPEI), which implies drought hazard-causing conditions. In addition, the entropy-theory-based drought index (ETDI) is introduced to incorporate a spatial comparison with GTDI to illustrate the rationality of gaming weight integration, as both entropy theory and game theory belong to linear combination methods in the development of the integrated drought index and entropy theory has been applied in related research. Leaf area index (LAI) data are employed to confirm the reliability of GTDI in identifying drought by comparing it with SPEI, SSMI, and ETDI. Furthermore, a comparative analysis is conducted on the temporal trajectories and spatial evolution of the GTDI-identified drought to discuss GTDI's level of advancement in monitoring changes in hazard-causing and hazard-bearing impacts. The results show that GTDI has a very high correlation with single-type drought indices (SPEI and SSMI), and its gaming weight integration is more logical and trustworthy than that of ETDI. As a result, it outperforms ETDI, SPEI, and SSMI in recognizing drought spatiotemporally and is projected to replace single-type drought indices to provide a more accurate picture of actual drought. Additionally, GTDI exhibits the gaming feature, indicating a distinct benefit in monitoring changes in hazard-causing and hazard-bearing impacts. The case studies show that drought events in the Wei River basin are dominated by a lack of precipitation. The hazard-causing index, SPEI, dominates the early stages of a drought event, whereas the hazard-bearing index, SSMI, dominates the later stages. This study surely serves as a helpful reference for the development of integrated drought indices as well as regional drought prevention and monitoring. [ABSTRACT FROM AUTHOR]

Memristive devices such as resistive switching memories and artificial synapses have emerged as promising technologies to overcome the technological challenges associated with the von Neumann bottleneck. Recently, lead halide perovskites have drawn substantial research attention as the candidate material for memristors and artificial synapses due to their unique optoelectronic properties, solution processability, and mechanical flexibility. However, the toxicity of lead‐containing species has raised major concerns for health and the environment, which makes it crucial to transition from lead‐based to lead‐free materials for practical applications. Herein, the recent progress of lead‐free metal halides including perovskites and perovskite analogs for resistive memory and artificial synapse is reviewed. Initially, the fundamentals of lead‐free materials and switching mechanisms are introduced. Next, the material design, fabrication technique, and device performance are summarized and critically evaluated for each metal halide species. Finally, the challenges of the lead‐free metal halides toward memristors and artificial synapses are outlined and discussed, and some potential research directions for future study are proposed. [ABSTRACT FROM AUTHOR]

Lead (Pb) halide perovskites have witnessed highly promising achievements for high-efficiency solar cells, light-emitting diodes (LEDs), and photo/radiation detectors due to their exceptional optoelectronic properties. However, compound stability and Pb toxicity are still two main obstacles towards the commercialization of halide perovskite-based devices. Therefore, it is of substantial interest to search for non-toxic candidates with comparable photophysical characteristics. Metal-halide double perovskites (MHDPs), A2BBʹX6, are recently booming as promising alternatives for Pb-based halide-perovskites for their non-toxicity and significantly enhanced chemical and thermodynamic stability. Moreover, this family exhibits rich combinatorial chemistry with tuneable optoelectronic properties and thus a great potential for a broad range of optoelectronic/electronic applications. Herein, we present a comprehensive review of the MHDPs synthesized so far, and classified by their optical and electronic properties. We systematically generalize their electronic structure by both theoretical and experimental efforts to prospect the relevant optoelectronic properties required by different applications. The progress of the materials in various applications is explicated in view of the material structure-function relationship. Finally, a perspective outlook to improve the physical and optoelectronic properties of the materials is proposed aiming at fostering their future development and applications.

Reproductive traits have a high economic value in goat breeding, and increasing the number of lambs produced by ewes is of great importance to improve the production efficiency of goat farming. Lambing traits in goats are low heritability traits, but their genetic basis is ultimately determined by genes. This study aimed to investigate the relationship between INHA, RARG, and PGR gene polymorphisms and production performance, such as lambing, cashmere production, milk production, and body size in Liaoning cashmere goats. A total of six single nucleotide polymorphisms (SNPs) loci were identified in these three genes, G144A and T504C on the INHA gene, A56G, G144A, G490C on the RARG gene, and G109519T on the PGR gene. For lambing and cashmere production traits, the AA genotype of G144A on the INHA gene, TT on the T504C genotype, GG genotype of G144A on the INHA gene, A56G, G144A, and T504C on RARG and G109519T on PGR gene are dominant genotypes. AATT is a dominant haplotype combination. Allele G can be used as a molecular marker for lambing, cashmere, and milk production traits in Liaoning cashmere goats. Marker-assisted selection can be used for early selection to achieve improvement of genetic traits in Liaoning cashmere goats. [ABSTRACT FROM AUTHOR]

The overexpression of p21-activated kinase 4 (PAK4) is associated with a variety of cancers. In this paper, the binding modes and inhibitory mechanisms of four 7H-pyrrolo[2,3-d]pyrimidine competitive inhibitors of PAK4 were investigated at the molecular level, mainly using molecular dynamics simulations and binding free energy calculations. The results show that the inhibitors had strong interactions with the hinge region, the β-sheets, and the residues with charged side chains around the 4-substituent. The terminal amino group of the inhibitor 5n was different from the other three, which could cause the enhancement of hydrogen bonds or electrostatic interactions formed with the surrounding residues. Thus, inhibitor 5n had the strongest inhibition capacity. The different halogen atoms on the 2-substituents of the inhibitors 5h, 5g, and 5e caused differences in the positions of the 2-benzene rings and affected the interactions of the hinge region. It also affected to some extent the orientations of the 4-imino groups and consequently their affinities for the surrounding charged residues. The combined results lead to the weakest inhibitory capacity of inhibitor 5e. [ABSTRACT FROM AUTHOR]