In this work, a record high thermoelectric figure‐of‐merit ZT of 1.6 ± 0.2 at 873 K in p‐type polycrystalline Bi0.94Pb0.06CuSe1.01O0.99 by a synergy of rational band manipulation and novel ...nanostructural design is reported. First‐principles density functional theory calculation results indicate that the density of state at the Fermi level that crosses the valence band can be significantly reduced and the measured optical bandgap can be enlarged from 0.70 to 0.74 eV by simply replacing 1% O with 1% Se, both indicating a potentially reduced carrier concentration and in turn, an improved carrier mobility and a boosted power factor up to 9.0 µW cm−1 K−2. Meanwhile, comprehensive characterizations reveal that under Se‐rich condition, Cu2Se secondary microphases and significant lattice distortions triggered by Pb‐doping and Se‐substitution can be simultaneously achieved, contributing to a reduced lattice thermal conductivity of 0.4 W m−1 K−1. Furthermore, a unique shear exfoliation technique enables an effective grain refinement with higher anisotropy of the polycrystalline pellet, leading to a further improved power factor up to 10.9 µW cm−1 K−2 and a further reduced lattice thermal conductivity of 0.30 W m−1 K−1, which gives rise to record high ZT.
A record high thermoelectric figure‐of‐merit ZT of 1.6 ± 0.2 at 873 K in p‐type polycrystalline Bi0.94Pb0.06CuSe1.01O0.99 by a synergy of rational band manipulation and novel nanostructural design is reported.
It is highly desirable, although very challenging, to develop self‐healable materials exhibiting both high efficiency in self‐healing and excellent mechanical properties at ambient conditions. ...Herein, a novel Cu(II)–dimethylglyoxime–urethane‐complex‐based polyurethane elastomer (Cu–DOU–CPU) with synergetic triple dynamic bonds is developed. Cu–DOU–CPU demonstrates the highest reported mechanical performance for self‐healing elastomers at room temperature, with a tensile strength and toughness up to 14.8 MPa and 87.0 MJ m−3, respectively. Meanwhile, the Cu–DOU–CPU spontaneously self‐heals at room temperature with an instant recovered tensile strength of 1.84 MPa and a continuously increased strength up to 13.8 MPa, surpassing the original strength of all other counterparts. Density functional theory calculations reveal that the coordination of Cu(II) plays a critical role in accelerating the reversible dissociation of dimethylglyoxime–urethane, which is important to the excellent performance of the self‐healing elastomer. Application of this technology is demonstrated by a self‐healable and stretchable circuit constructed from Cu–DOU–CPU.
A dimethylglyoxime–urethane (DOU)‐based polyurethane elastomer self‐heals immediately at room temperature and shows world‐record strength and toughness. Cu(II)DOU coordination bonds greatly strengthen the materials while enhancing the dynamics of the DOU bonds to facilitate self‐healing. This material design reconciles the contradictory properties of mechanical robustness and self‐healing efficiency, providing a powerful new strategy to create high‐performance self‐healing materials.
Reinforced concrete structures exposed to marine environments often experience chloride ingress, reinforcement corrosion, and corrosion‐induced cracking. The electrochemical repair method is a ...promising concrete rehabilitation technique with advantages of non‐destructive and economic performance in crack repair, chloride removal, and corrosion protection, which is particularly suitable for structures exposed to marine environments. This work presents an innovative methodology for modeling the mechanical, transport, and chemical process during electrochemical treatment for marine concrete structures. The entire process from concrete cracking up to repairing can be successfully reproduced and digitally visualized. The first sub‐model calculates the corrosion‐induced cracking process at the mesoscopic level with the consideration of local mechanical variances of concrete composites. Then, a reactive transport sub‐model is established to reveal the interactions and electrochemical reactions among various species of ions. A crack repair sub‐model is built to visualize the moving interface between chemical deposition and crack surface. Through combining the three sub‐models, the interconnected influencing factors in practical engineering can be quantitively investigated. The calculation results show that, compared with electrolyte concentration, the influence of current density on crack closure rates are more obvious. Other factors such as steel reinforcement diameter and crack distribution pattern, which have not been previously reported are highlighted. These findings can guide the application of electrochemical repair in practical engineering.
Esophageal cancer (EC) is a type of aggressive cancer without clinically relevant molecular subtypes, hindering the development of effective strategies for treatment. To define molecular subtypes of ...EC, we perform mass spectrometry-based proteomic and phosphoproteomics profiling of EC tumors and adjacent non-tumor tissues, revealing a catalog of proteins and phosphosites that are dysregulated in ECs. The EC cohort is stratified into two molecular subtypes-S1 and S2-based on proteomic analysis, with the S2 subtype characterized by the upregulation of spliceosomal and ribosomal proteins, and being more aggressive. Moreover, we identify a subtype signature composed of ELOA and SCAF4, and construct a subtype diagnostic and prognostic model. Potential drugs are predicted for treating patients of S2 subtype, and three candidate drugs are validated to inhibit EC. Taken together, our proteomic analysis define molecular subtypes of EC, thus providing a potential therapeutic outlook for improving disease outcomes in patients with EC.
The service life of concrete-based infrastructure and buildings is seriously shortened due to the chloride-induced durability problems. In order to clarify the transport mechanism associated with the ...response of inclusion structures, this paper presents a numerical study on the influence caused by morphology and heterogeneity of individual phases, in which the concrete is treated as a three-phase composite including mortar, aggregates and interfacial transition zone (ITZ). A series of meso-scale numerical models with different shapes and volume fractions of aggregates are developed for examining the effects of aggregates on ionic migration. Unlike in most of the existing published research work in this area, a multi-component ionic transport theory which takes ionic interactions into consideration has been utilised in this study. By coupling mass conservation and Poisson’s equations, the time-spatial concentration distribution results for individual ionic species are obtained. Other important factors such as the externally applied electric field, concrete heterogeneity, ionic binding and ITZ are also considered and examined in this study. Through this relatively thorough numerical analysis, some important features about the effect of aggregate shape based on multi-species modelling, which have previously not been properly investigated, are highlighted.
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•GEP algorithm is utilized for predicting mechanical properties of concrete incorporating WFS.•Simple and accurate formulations with a wide range of applicability have been ...proposed.•Proposed models can promote the re-utilization of hazardous WFS for development of green concrete.
Waste foundry sand (WFS) is a major pollutant generated from metal casting foundries and is classified as a hazardous material due to the presence of organic and inorganic pollutants which can cause adverse environmental impact. In order to promote the re-utilization of WFS, gene expression programming (GEP) has been employed in this study to develop empirical models for prediction of mechanical properties of concrete made with WFS (CMWFS). An extensive and reliable database of mechanical properties of CMWFS is established through a comprehensive literature review. The database comprises of 234 compressive strength, 163 split tensile strength and 85 elastic modulus results. The four most influential parameters i.e. water-to-cement ratio, WFS percentage, WFS-to-cement content ratio and fineness modulus of WFS are considered as the input parameters for modelling. The mechanical properties can be estimated by the application of proposed simplified mathematical expressions. The performance of the models is assessed by conducting parametric analysis, applying statistical checks and comparing with regression models. The results reflected that the proposed models are accurate and possess a high generalization and prediction capability. The findings of this study can enhance the re-usage of WFS for development of green concrete leading to environmental protection and monetary benefits.
Recent realization of high sodium‐ion conductivities (>10−2 S cm−1) in inorganic solid electrolytes (ISEs) at room temperature will certainly trigger a boom in all‐solid‐state sodium batteries ...(ASS‐SBs). However, their electrochemical stable windows and compatibility to high capacity/voltage electrodes are unsatisfactory. Developing ideal ISEs that deliver high Na+ ion conductivities, good electrochemical/chemical stability, and compatible electrode/ISE interface is key for the success of high‐performance ASS‐SBs. In this review, focus is mainly on the fundamentals and strategies to optimize ASS‐SB performances from the aspects of ISE and interface, and note that interfacial issues are also ISE‐related. The latest progress in ISEs, including fundamentals of the sodium‐ion conduction mechanism, key parameters dominating the Na+ ion conduction in terms of crystal structure, lattice dynamics, point defects, and grain boundaries, and prototyping strategies for cell design, are elaborated from the perspectives of material and defect chemistry. The key challenges and future opportunities are discussed, and rational solutions are provided.
This review discusses the fundamentals of sodium ionic conduction in inorganic solid electrolytes (ISEs), identifies the key parameters dominating the sodium ionic conduction, and proposes prototyping strategies for both solid electrolyte and full cell design, from the perspectives of materials and defect chemistry. The key challenges and future opportunities for all‐solid‐state sodium batteries using ISEs are also discussed in detail.
The difluoromethyl group (CF2H) is of great interest in the area of medicinal chemistry. However, the investigation of molecular scaffolds containing this group has been hampered by the limitation of ...synthetic methods for the introduction of CF2H into heteroarenes. Herein we disclose a new strategy for the direct introduction of a difluoromethyl group into heteroarenes via the copper-mediated C–H oxidative difluoromethylation of heteroarenes with TMSCF2H. This mild and regioselective method enables the convenient synthesis of a range of difluoromethylated heteroarenes in high yields. The usage of 9,10-phenanthrenequinone (PQ) as an oxidant is critical to the success of this new difluoromethylation reaction.
Alkali-activated binders for concrete composites are emerging as the available low-embodied-carbon alternatives to ordinary Portland cement (OPC). Despite decades of research, the durability of ...alkali-activated concrete remains a concern, especially the issues related to chloride penetration and the potential for chloride-induced corrosion of embedded steel bars. In this study, a multi-phase, multi-component ionic numerical model is developed to investigate the chloride transport in alkali-activated fly ash/slag (AAFS) concretes. The model framework considers the porosity of concrete, the chloride binding, and the electrochemical coupling between multi-species. Based on the proposed model, the parametric studies of a series of influencing factors on both chloride transport and initiation time of reinforcement corrosion are performed and discussed. The results indicate that the slag content and the water to binder ratio are the dominant factors affecting chloride penetration and corrosion initiation time of steel bars in AAFS concretes due to their greater contributions to reduce the porosity, while the aggregate volume fraction presents a limited effect compared with other factors. The transport model proposed in this study brings insights to the prediction of the service life of alkali-activated reinforced concrete structures.
•A multi-phase, multi-species model is developed to investigate the chloride transport behaviour in the binary AAFS system.•The proposed model considers the porosity of concrete, chloride binding and electrochemical coupling between multi-species.•The influence mechanism of relevant factors on both chloride penetration and reinforcement corrosion onset is discussed.•Slag content is proved to be the most important influencing factor on chloride transport in AAFS concretes.
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