•A mesoscale concrete framework which combines decohesion and friction fracture process is developed.•Model is verified and validated with good agreements with experimental observations under various ...loading conditions.•Evolution of fracture process zone is naturally captured by initiation and propagation of microcracks.•Size effect on the fracture process zone is identified and discussed accordingly.
A comprehensive mesoscopic investigation has been conducted to examine the evolution of the fracture process zone (FPZ), using notched plain concrete beams subjected to three-point bending as a generic representation. The concrete beams are modelled as random heterogeneous materials containing three components, namely coarse aggregates, mortar and the interface transition zone (ITZ). To better represent the fracture process in concrete, a coupled cohesive-contact interface approach is employed to model the crack initiation, crack propagation and the friction mechanismsduring the fracture process. Thus,the FPZ is naturally captured in the simulation as the zone composed by microcracks along the ITZ or through the mortar matrix in the mesoscale model. The macroscopic response of load-deformation curves as well as the shapes and sizes of FPZ calculated from numerical results are validated against experimental observationsand good agreement is achieved. Subsequent modelling results demonstrate that the FPZ tend to exhibit a main crack and multiple secondary microcracks. During the growth of the main crack, new microcracks initiate while some microcracks formed earlier stop growing and even close. The evolution path of the FPZ is strongly irregular due to the random spatial distribution of the aggregate particles with weak ITZs. The influence of the size effect on the FPZ is also investigated from the numerical simulation. Results show that the width of the FPZ is insensitive to the beam size but the length of the FPZ is strongly dependent on the beam size, and such characteristics of the FPZ are deemed to be intrinsic reasons for the overall size effect phenomenon in concrete structures.
Compared to traditional lithium-ion batteries, solid-state batteries (SSBs) are characterized by higher safety and energy density, so the key component, solid-state electrolyte (SSE) has received ...considerable attention. The most common SSEs can be divided into three types: oxides, sulfides, and polymers. This paper mainly presents and discusses the latest research on unconventional solid-state electrolytes (USSEs) such as halides, zeolites, etc., focusing on their properties, structures, costs, synthesis methods, etc. Although SSEs such as halides are less well known, they are becoming a very hot topic due to their numerous advantages, such as: a) ionic conductivity at room temperature of more than 0.6 mS cm−1; b) oxidation potential exceeding 4V, which means that they are more stable than most other types of SSEs; c) high stability in dry air (i.e., easier handling during the fabrication process), unlike sulfides, which decompose to produce toxic gases; d) some halides can be synthesized by the liquid phase method, which is more suitable for mass production. Then, some typical USSEs were compared with conventional SSEs such as oxides and liquid electrolytes in various aspects. The paper concludes with a discussion on future research directions for USSEs and the challenges to be overcome in practical applications.
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•Unconventional solid-state electrolytes such as halide and zeolite.•Higher stability, ionic conductivity and energy density.•Better safety, cost-effectiveness and mechanical property.•Mass production possibilities from the liquid phase method.
Developing effective and safe catalysts operated in the in-depth removal of iodinated X-ray contrast media is important for overcoming slow removal efficiency-induced highly toxic iodine-replaced ...disinfection byproducts (I-DBPs). In this study, a novel oxygen vacancies enriched heterogeneous biochar catalyst (Mo-Co-ECM) from the invasive plant was synthesized by a facile one-step hydrothermal carbonization method and used for the in-depth removal of iohexol (IOH) by the activation of peroxymonosulfate (PMS). The results indicated that after adding PMS for 3 min, the removal efficiency of IOH in Mo-Co-ECM/PMS system reached 100% and exhibited a superior degradation efficiency compared to Co-ECM/PMS and ECM/PMS system. Only nine I-DBPs were found during the degradation, which were dominated by small molecules compounds (MW<400). The in-depth degradation suppresses the formation of the toxic intermediates. The density functional theory and electron spin resonance showed that due to the existence of Mo and oxygen vacancies, the electron transfer ability was improved, which accelerated the cycle of Co3+/Co2+, so as to enhance the catalytic activity of Mo-Co-ECM/PMS system. This study is expected to provide a general way for decreasing the production of toxic intermediates during the advanced oxidation of contaminants, meanwhile recovering resources.
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•The oxygen vacancies enriched bimetal biochar was facilely developed for PMS activation.•In-depth degradation of IOH can be achieved after adding PMS for 3 min.•Significant role of oxygen vacancies in improved the electron transfer ability of Co was revealed.•The formation of toxic intermediates is suppressed due to the in-depth degradation.
•A UHPLC-QTOF-MS method was developed for multi-residue analysis in eggs.•A single-injection workflow was used for screening analysis.•QTOF-MS and QqQ-MS were comparable with residue concentrations ...over 0.01 mg·kg−1.•The reliability of QTOF-MS identification decreased substantially at trace levels.
A multi-class screening method for the determination of veterinary drugs and pesticides in eggs was developed by high performance liquid chromatography quadrupole-time-of-flight mass spectrometry (HPLC-QTOF-MS). A single-injection workflow was developed for qualitative analysis, and method validation was conducted in terms of retention time deviation (ΔRt), exact mass error (Δm), selectivity, specificity, precision and trueness. The characteristic fragment ions in information dependent acquisition (IDA) mode were summarized for retrospective and non-target screening. Five of 70 samples were found positive with sulfachloropyridazine, sulfamonomethoxine and fipronil sulfone. Compared with triple-quadrupole (QqQ) MS method, the obtained results showed that QTOF-MS gave comparable results to QqQ-MS with residue concentrations higher than 10 μg·kg−1, whereas QqQ-MS was more powerful at lower concentrations (<1 μg·kg−1). Moreover, the amount of fragment ions acquired by HPLC-QTOF-MS decreased substantially at trace levels, which may be a potential cause of reduced reliability of identification.
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•Working principle of supercapacitors (SCs) is introduced.•Recent advances on electrode materials for flexible SCs are reviewed.•Various ways to enhance the performance of flexible ...SCs are discussed.•Current challenges and future prospect of flexible SCs are suggested.
In recent years, with the rapid economic development, real-time monitoring of human health has received extensive attention. Wearable health monitoring equipment with good malleability and resistance to distortion makes great progress. The flexible supercapacitors integrated into the textile are characterized by a simple production process, low cost, fast charge,-discharge speed, and long cycle life. Therefore it has superior performance and broad research prospects. This review mainly introduces the recent advances and challenges of flexible supercapacitors, focusing on various flexible substrates' synthesis and performance. It summarizes the most representative flexible electrode materials at this stage. The future development trend and direction of flexible supercapacitors are discussed as well. Finally, the challenges in practical applications are considered.
Bacterial endospores are formed by certain bacteria, such as Bacillus subtilis or the pathogenic Bacillus anthracis and Clostridioides difficile, to allow survival in environmental conditions which ...are lethal to vegetative bacteria. The spores possess a particular architecture and molecular inventory which endow them with a remarkable resistance against desiccation, heat and radiation. Another remarkable spore feature is their rapid return to vegetative growth during spore germination and outgrowth. The underlying processes of this latter physiological and morphological transformation involve a number of different events, some of which are mechanistically not entirely understood. One of these events is the expansion of the central spore core, which contains the DNA, RNA and most spore enzymes. To date, it has been unclear how the ~1.3- to 1.6-fold expansion of the core membrane surface area that accompanies core expansion takes place, since this occurs in the absence of significant if any ATP synthesis. In the current work, we demonstrate the presence of intracellular membrane structures in spores located just below the core membrane. During spore germination these internal core membranes disappear when the core size increases, suggesting that they are integrated into the core membrane to allow core expansion. These intracellular membranes are most probably present as more or less compressed vesicles or tubules within the dormant spore core. Investigations of spores from different species suggest that these intracellular membrane structures below the core membrane are a general feature of endospore forming bacteria.
•Area wide spatiotemporal modelling to improve of building structural product stock estimations.•Bottom up modelling and granular quantification of specific product categories by building ...types.•Spatially-explicit LCA of urban stocks shows where embodied carbon is accumulated.•First step integration of spatially mapping material stocks and environmental footprints to support the business modelling for future circular economy building construction systems.
The building construction sector consumes significant quantities of resources, generates high levels of waste and creates many negative environmental impacts including carbon emissions. These problems are characteristic of linear value chains. In contrast, a circular economy approach to building construction has the potential to moderate these three problems. One way this can be achieved is to enable in-use building stocks as a repository of products for future reuse, sometimes referred to as urban mining. A key stage in such a shift is to be able to quantify stocks of construction materials and assess their direct reuse potential as products against criteria such as their location, age, type, and embodied carbon. The majority of studies of building stocks have focused on producing aggregated quantities of materials, regardless of the required information for assessing the potential value streams of future reuse. In this paper, a framework for spatiotemporal mapping of building structural products integrating external geometries and construction history is presented. To demonstrate its capacity, the stocks of clay bricks within the external walls of buildings are assessed where six types of buildings and four types of bricks are specified. Dimensions, weights, ages and embodied carbon of materials are estimated for case studies of three urban regions in Northern England: Manchester, Leeds and Bradford, and the results are spatially mapped for the city of Bradford. The paper provides the first systematic and comprehensive area-wide model to evaluate stocks of building structural products for future urban mining and circular economy of building construction systems.
Aqueous zinc ion batteries (AZIBs) show a great potential for next‐generation energy storage due to their high safety and high energy density. However, the severe side reactions of zinc negative ...electrode largely hinder the further application of AZIBs. Herein, trace tris(hydroxymethyl)aminomethane (Tris) additive with rich lone‐pair‐electrons and zincophilic sites is firstly introduced to achieve long‐term and highly reversible Zn plating/stripping. Specifically, Tris not only regulates the solvation structure of Zn2+, but is also adsorbed vertically on the Zn anode surface with a changed coordination intensity during the plating/stripping process of Zn to generate an in situ dynamic adsorption layer for the first time. The dynamic adsorption layer could successively attract the solvated Zn2+ and then promote the de‐solvation of the solvated Zn2+ owing to the orientation polarization with regularly‐changed applied electric field, the volume rejection effect, and strong intermolecular force towards H2O of the vertically‐adsorbed Tris. Therefore, an improved Zn2+‐transport kinetics as well as the inhibition of side reactions of Zn anode are successfully realized. Accordingly, the Zn||Zn symmetric cell provides an ultra‐long cycle life of 2600 h. Furthermore, the Zn||MnO2 full cell with Tris could demonstrate a high capacity and structural stability for practical applications.
A dynamic anode/electrolyte interface coupled with regulated solvation structures strategy is firstly realized with Tris additive for aqueous zinc‐ion batteries. The dynamic adsorption layer could successively attract solvated‐Zn2+, then promote the de‐solvation by the orientation polarization, the volume rejection effect and strong intermolecular force of the vertically‐adsorbed Tris, leading to an improved Zn2+‐transport kinetics and the inhibition of side reactions.
Reproductive systems play an important role in the ecological function of species, but little is known about how climate change, such as global warming, may affect the reproductive systems of ...microbes. In this study, 116 Phytophthora infestans isolates sampled from five different altitudes along a mountain were evaluated under five temperature regimes to determine the effects of historical and experimental temperature on the reproductive system of the pathogen. Both altitude, a proxy for historical pathogen adaptation to temperature, and temperature used in the experiment affected the sexual reproduction of the pathogen, with experimental temperature, that is, contemporary temperature, playing a role several times more important than historical temperature. Furthermore, the potential of sexual reproduction, measured by the number of oospores quantified, increased with the temperature breadth (i.e., difference between the highest and lowest temperature at which sexual reproduction takes place) of the pathogen and reached the maximum at the experimental temperature of 21°C, which is higher than the annual average temperature in many potato‐producing areas. The results suggest that rising air temperature associated with global warming may increase the potential of sexual reproduction in P. infestans. Given the importance of sexuality in pathogenicity and ecological adaptation of pathogens, these results suggest that global warming may increase the threat of P. infestans to agricultural production and other ecological services and highlight that new epidemiological strategies may need to be implemented for future food security and ecological resilience.
The presence of Bryde's whales (Balaenoptera edeni) in the Beibu Gulf, China has been reported since 2016. In the current study, in situ Bryde's whale vocalizations were recorded. Bouts of frequency ...modulated repetitive and diversified calls were recorded. Repetitive calls were recorded when 1–3 whales were present within 2 km of the boat and were probably emitted by a single whale and functioned as contact calls. Repetitive calls were divided into biphonation downswept tonals and downswept tonals. Diversified calls were recorded when 4–7 whales were present within 2 km of the boat and were probably associated with acoustic exchanges between or among conspecifics. Diversified calls occasionally contained inflection points, frequency jumps, and break point features. The frequency band of Bryde's whale vocalizations overlapped highly with background noise. Most vocalizations in the current study were different than those previously reported for this species. Therefore, the findings of this study provide more information on the known acoustic repertoire of Bryde's whales and provide a basis for noninvasive monitoring of Bryde's whale with passive acoustic methods and for developing mitigation and conservation protocols to ensure their future viability.
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