Aqueous monovalent‐ion batteries have been rapidly developed recently as promising energy storage devices in large‐scale energy storage systems owing to their fast charging capability and high power ...densities. In recent years, Prussian blue analogues, polyanion‐type compounds, and layered oxides have been widely developed as cathodes for aqueous monovalent‐ion batteries because of their low cost and high theoretical capacity. Furthermore, many design strategies have been proposed to expand their electrochemical stability window by reducing the amount of free water molecules and introducing an electrolyte addictive. This review highlights the advantages and drawbacks of cathode and anode materials, and summarizes the correlations between the various strategies and the electrochemical performance in terms of structural engineering, morphology control, elemental compositions, and interfacial design. Finally, this review can offer rational principles and potential future directions in the design of aqueous monovalent‐ion batteries.
The aqueous monovalent‐ion batteries have gained tremendous attention from the scientific community due to their fast charging capability, resulting from the outstanding ionic conductivity of aqueous electrolytes (twice as high as for organic electrolytes), and the smaller hydrated ionic radius and lower hydration free energy of monovalent ions compared with those of multivalent ions.
Stable water-in-oil emulsion is essential to digital PCR and many other bioanalytical reactions that employ droplets as microreactors. We developed a novel technology to produce monodisperse emulsion ...droplets with high efficiency and high throughput using a bench-top centrifuge. Upon centrifugal spinning, the continuous aqueous phase is dispersed into monodisperse droplet jets in air through a micro-channel array (MiCA) and then submerged into oil as a stable emulsion. We performed dPCR reactions with a high dynamic range through the MiCA approach, and demonstrated that this cost-effective method not only eliminates the usage of complex microfluidic devices and control systems, but also greatly suppresses the loss of materials and cross-contamination. MiCA-enabled highly parallel emulsion generation combines both easiness and robustness of picoliter droplet production, and breaks the technical challenges by using conventional lab equipment and supplies.
The solar energy potential of urban buildings is important for China’s sustainable economic development. Previous studies have focused on creating regional solar maps or estimating the irradiation of ...building roofs. This study estimates the practical potential of solar energy in cities with a novel roof-facade framework. Improvements have been made to make it more practical by integrating roofs and facades, considering view shading effects, and correcting weather impacts. The developed framework was applied to calculate the solar energy potential for 10 cities in China on a microscopic scale. The annual solar irradiation ranges from 41.39 to 772.94 TWh, with an electric capacity of 6.21–115.94 TWh. A dataset of the annual solar irradiation for more than 1.44 million buildings of the 10 cities is now available as a free download (https://gis.nju.edu.cn/rs_01.asp?ID=74&type_1=425). The results can support decision-making related to reducing reliance on conventional energy sources and reducing carbon emissions.
•Solar irradiance can be calculated on not only building rooftops but also side walls.•Point cloud is generated from 3D building models.•The influences of shadows and view-sky factors caused by surrounding buildings are considered.•Solar irradiation affected by real-world weather conditions are corrected.
The key role played by carbon dioxide in global temperature cycles has stimulated constant research attention on carbon capture and storage. Among the various options, lithium–carbon dioxide ...batteries are intriguing, not only for the transformation of waste carbon dioxide to value-added products, but also for the storage of electricity from renewable power resources and balancing the carbon cycle. The development of this system is still in its early stages and faces tremendous hurdles caused by the introduction of carbon dioxide. In this review, detailed discussion on the critical problems faced by the electrode, the interface, and the electrolyte is provided, along with the rational strategies required to address these problematic issues for efficient carbon dioxide fixation and conversion. We hope that this review will provide a resource for a comprehensive understanding of lithium–carbon dioxide batteries and will serve as guidance for exploring reversible and rechargeable alkali metal-based carbon dioxide battery systems in the future.
Abstract Sluggish kinetics of the CO 2 reduction/evolution reactions lead to the accumulation of Li 2 CO 3 residuals and thus possible catalyst deactivation, which hinders the long-term cycling ...stability of Li-CO 2 batteries. Apart from catalyst design, constructing a fluorinated solid-electrolyte interphase is a conventional strategy to minimize parasitic reactions and prolong cycle life. However, the catalytic effects of solid-electrolyte interphase components have been overlooked and remain unclear. Herein, we systematically regulate the compositions of solid-electrolyte interphase via tuning electrolyte solvation structures, anion coordination, and binding free energy between Li ion and anion. The cells exhibit distinct improvement in cycling performance with increasing content of C-N species in solid-electrolyte interphase layers. The enhancement originates from a catalytic effect towards accelerating the Li 2 CO 3 formation/decomposition kinetics. Theoretical analysis reveals that C-N species provide strong adsorption sites and promote charge transfer from interface to *CO 2 2− during discharge, and from Li 2 CO 3 to C-N species during charge, thereby building a bidirectional fast-reacting bridge for CO 2 reduction/evolution reactions. This finding enables us to design a C-N rich solid-electrolyte interphase via dual-salt electrolytes, improving cycle life of Li-CO 2 batteries to twice that using traditional electrolytes. Our work provides an insight into interfacial design by tuning of catalytic properties towards CO 2 reduction/evolution reactions.
In this paper, the effects of acceptor dopants on the synthesis, sintering and properties of KNN ceramics were studied for (K0.5Na0.5)(Nb0.994A0.006)O3−δ (A=Ge4+, Ga3+, Zn2+, Mn2+, Ni2+, and Cu2+) ...ceramics. The results reveal that the eutectic phase(s) is (are) formed between the acceptor oxide and alkali metal carbonate, thereby significantly improving the sinterability of the materials. Compared to the trivalent and tetravalent acceptor dopants, divalent dopant can lead to higher Qm values, most likely due to the formation of defect complexes.
Single-cell whole-genome sequencing (scWGS) is mainly used to probe intercellular genomic variations, focusing on the copy number variations or alterations and the single-nucleotide variations (SNVs) ...occurring within single cells. Single-cell whole-genome amplification (scWGA) needs to be applied before scWGS but is challenging due to the low copy number of DNA. Besides, many genomic variations are rare within a population of cells, so the throughput of currently available scWGA methods is far from satisfactory. Here, we integrate a one-step micro-capillary array (MiCA)-based centrifugal droplet generation technique with emulsion multiple displacement amplification (eMDA) and demonstrate a high-throughput scWGA method, MiCA-eMDA. MiCA-eMDA increases the single-run throughput of scWGA to a few dozen, and enables the assessment of copy number variations and alterations at 50-kb resolution. Downstream target enrichment further enables the detection of SNVs with 20% allele drop-out.
A sudden rainstorm that occurred in the northeast Sichuan Basin of China in early May 2017 was associated with a southwest low-level jet (SWLJ) and a mountainous low-level jet (MLLJ). This study ...investigates the impact of the double low-level jets (LLJs) on rainfall diurnal variation by using the data from ERA5 reanalysis, and explores the characteristics of water vapor transport, including the main paths and sources of moisture, by using the HYSPLIT-driven data of the ERA—interim, GDAS (Global Data Assimilation System), and NCEP/NCAR reanalysis data. The analysis shows that the sudden rainstorm in the mountain terrain was located at the left side of the large-scale SWLJ at 700 hPa, and at the exit region of the meso-scale MLLJ at 850 hPa. The double LLJs provide favorable moisture conditions, and the enhancement (weakening) of the LLJs is ahead of the start (end) of the rainstorm. The capacity of the LLJ at 850 hPa with respect to moisture convergence is superior to that at 700 hPa, especially when the MLLJ and the southerly LLJ at 850 hPa appear at the same time. The HYSPLIT backward trajectory model based on Lagrangian methods has favorable applicability in the event of sudden rainstorms in mountainous terrain, and there is no special path of moisture transport in this precipitation event. The main moisture sources of this process are the East China Sea–South China Sea, the Arabian Sea–Indian Peninsula, the Bay of Bengal, and the Middle East, accounting for 38%, 34%, 17% and 11% of the total moisture transport, respectively. Among them, the moisture transport in the Bay of Bengal and the South China Sea–East China Sea is mainly located in the lower troposphere, which is below 900 hPa, while the moisture transport in the Arabian Sea–Indian Peninsula and the Middle East is mainly in the middle and upper layers of the troposphere. The moisture changes of the transport trajectories are affected by the topography, especially the high mountains around the Sichuan Basin.
Sorghum is one of the oldest crops in the world, an important grain crop in northern China, and a major raw material in the liquor-brewing industry. The physicochemical properties, cooking ...characteristics, and starch quality of sorghum seeds considerably affect the liquor-brewing process.To select suitable sorghums for liquor brewing and to determine the cooking characteristics and starch physicochemical properties of different sorghum varieties, 30 types of sorghum were used in this study, and their compositions were compared; six types of sorghum were further studied for their cooking quality and starch physicochemical and pasting characteristics. Gas chromatography time of flight mass spectrometry was used to analyse the cooking aroma of sorghum seeds. Additionally, scanning electron microscopy, a rapid visco analyser, and a differential calorimetric scanner were used to analyse the microstructure of sorghum starch, starch pasting characteristics, and thermodynamic properties, respectively. The results revealed that the water absorption and saccharification forces of glutinous sorghum were higher than those of japonica sorghum and that the aroma substances were significantly different. Glutinous sorghum starch had high crystallinity, freeze-thaw stability, and enthalpy, thus indicating its structural stability.
This study provides a theoretical basis for the selection of wine raw materials in the future.
•This paper directly addresses the quality characteristics of a grain (sorghum) used in conversion to human food (brewing of baijiu liquor).•Through the comparative study of japonica sorghum and waxy sorghum, it is found that there are differences in cooking aroma between japonica sorghum and waxy sorghum, and waxy sorghum starch has higher crystallinity and gelatinization characteristics, which is more suitable for multi-round cooking technology of maotai-flavour liquor.•At present, there are few studies on the influence of sorghum varieties on liquor making, which can provide theoretical basis for the selection of raw materials in liquor production.
In the 5G and cloud computing environment, autonomous learning based on smart mobile devices has a significant effect on improving students’ vocabulary and vocabulary use. This paper adopts a ...combination of vocabulary testing and interviews, and by building an autonomous English vocabulary learning platform based on 5G and cloud computing technology, learners can learn and use vocabulary in real natural contexts anytime, anywhere through smart mobile devices. Experimental results show that real-time interaction and collaboration with teachers and other learners during the learning process greatly improve the efficiency and quality of their vocabulary learning.
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