Potassium‐ion batteries (KIBs) are a core energy storage device that can meet the need for scalable and affordable stationary applications because they use low‐cost and earth‐abundant potassium. In ...addition, KIB shares a similar storage mechanism with current Li‐ion batteries. As the key to optimizing a battery's performance, the development of high‐performance electrode materials helps to increase the feasibility of KIB technology. In this sense, phosphorus‐based materials (i.e., phosphorus and metal phosphide) with high theoretical capacity and low redox potential tick all the right boxes as a material of choice. A rapid glimpse at recent studies on phosphorus‐based anode materials for advanced KIBs is provided, covering the synthetic methods, reaction mechanisms, electrochemical properties, and performances. In addition, several promising strategies are highlighted to address the imminent challenges faced by phosphorus‐based anode materials, hoping to cast an insightful outlook for possible future direction in this field.
Phosphorus‐based materials have shown great potential as anodes for potassium‐ion batteries (KIBs) with high theoretical capacity and low redox potential. Early results on phosphorus‐based anode materials for advanced KIBs are summarized. The approaches to solve the huge volume change and poor electronic conductivity of these phosphorus‐based anodes in KIBs are discussed. Finally, possible further research directions are proposed.
To derive a less conservative stability criterion via Lyapunov-Krasovskii functional (LKF) method, in previous literature, multiple integral terms are usually introduced into the construction of ...LKFs. This article generalizes the results of previous literature by proposing a polynomial-type LKF, which contains the LKFs with multiple integral terms as special cases. In addition, a Jacobi-Bessel inequality is presented to bound the derivative of such LKF. As a result, an improved stability criterion of time-delay systems is established. Finally, two numerical examples are given to illustrate the effectiveness, and advantages of our method.
Owing to their significant physiological functions, especially as selective relays for translocation of physiological relevant species through cellular membranes, natural ion channels play important ...role in the living organisms. During the last decades, the field of self‐assembled ion channels has been continuously developed. Convergent multidimensional self‐assembly strategies have been used for the synthesis of unimolecular channels or non‐covalent self‐organized channels, designed to mimic natural ion channel proteins and for which a rich array of interconverting or adaptive channel conductance states can be observed. In this review, we give an overview on the development of various self‐assembled artificial channels in a bottom‐up approach, especially their design, self‐assembly behaviour, transport activity in lipid bilayer membranes, mechanism of transport and comparison with natural ion channels. Finally, we discuss their applications, the potential challenges facing in this field as well as future development and perspectives.
This Review gives an overview of the various types of supramolecular self‐assembled artificial ion‐channels: capsules and cages, macrocyclic stacks, tubular helical architectures.
The development of pressure sensors is crucial for the implementation of electronic skins and for health monitoring integrated into novel wearable devices. Tremendous effort is devoted toward ...improving their sensitivity, e.g., by employing microstructured electrodes or active materials through cumbersome processes. Here, a radically new type of piezoresistive pressure sensor based on a millefeuille‐like architecture of reduced graphene oxide (rGO) intercalated by covalently tethered molecular pillars holding on‐demand mechanical properties are fabricated. By applying a tiny pressure to the multilayer structure, the electron tunnelling ruling the charge transport between successive rGO sheets yields a colossal decrease in the material's electrical resistance. Significantly, the intrinsic rigidity of the molecular pillars employed enables the fine‐tuning of the sensor's sensitivity, reaching sensitivities as high as 0.82 kPa−1 in the low pressure region (0–0.6 kPa), with short response times (≈24 ms) and detection limit (7 Pa). The pressure sensors enable efficient heartbeat monitoring and can be easily transformed into a matrix capable of providing a 3D map of the pressure exerted by different objects.
Toward highly performing piezoresistive pressure sensors, a radically new type of sensor based on reduced graphene oxide is demonstrated. Functionalization of graphene oxide with flexible molecular springs allows generation of devices featuring high sensitivity, short response time, and ultralow detection limit, which can be applied to health monitoring and 3D mapping of the pressure.
This paper presents a novel model for blending remote sensing data of high spatial resolution (HSR), taken at infrequent intervals, with those available frequently but at low spatial resolution (LSR) ...in the context of monitoring and predicting changes in land usage and phenology. Named "SParse-representation-based SpatioTemporal reflectance Fusion Model" (SPSTFM), the model has been developed for predicting HSR surface reflectances through data blending with LSR scenes. Remarkably, this model forms a unified framework for fusing remote sensing images with temporal reflectance changes, phenology change (e.g., seasonal change of vegetation), or type change (e.g., conversion of farmland to built-up area), by establishing correspondences between structures within HSR images of given areas and their corresponding LSR images. Such corresponding relationship is achieved by means of the sparse representation, specifically by jointly training two dictionaries generated from HSR and LSR difference image patches and sparse coding at the reconstruction stage. SPSTFM was tested using both a simulated data set and an actual data set of Landsat Enhanced Thematic Mapper Plus-Moderate Resolution Imaging Spectroradiometer acquisitions. It was also compared with other related algorithms on two types of data: images primarily with phenology change and images primarily with land-cover type change. Experimental results demonstrate the superiority of SPSTFM in capturing surface reflectance changes on both categories of images.
Although single-atomically dispersed metal-N
on carbon support (M-NC) has great potential in heterogeneous catalysis, the scalable synthesis of such single-atom catalysts (SACs) with high-loading ...metal-N
is greatly challenging since the loading and single-atomic dispersion have to be balanced at high temperature for forming metal-N
. Herein, we develop a general cascade anchoring strategy for the mass production of a series of M-NC SACs with a metal loading up to 12.1 wt%. Systematic investigation reveals that the chelation of metal ions, physical isolation of chelate complex upon high loading, and the binding with N-species at elevated temperature are essential to achieving high-loading M-NC SACs. As a demonstration, high-loading Fe-NC SAC shows superior electrocatalytic performance for O
reduction and Ni-NC SAC exhibits high electrocatalytic activity for CO
reduction. The strategy paves a universal way to produce stable M-NC SAC with high-density metal-N
sites for diverse high-performance applications.
Identifying the structure of a polycentric city is vital to various studies, such as urban sprawl and population movement dynamics. This paper presents an efficient and reliable method that uses ...multi-source geospatial big data, including nighttime light imagery and social media check-in maps, to locate the main center and subcenters of a polycentric city. Unlike traditional methods that rely on statistical data categorized by administrative units, the proposed method can effectively identify the boundaries of urban centers, and the data source guarantees a timely monitoring and update. Four main procedures are involved: 1) a new observation unit is developed using object-oriented segmentation; 2) main centers are located using cluster analysis (Local Moran's I); 3) subcenter candidates are selected using significant positive residuals from geographically weighted regression (GWR); and 4) final centers are filtered using global natural breaks classification (NBC). These steps can be reproduced in different regions. To evaluate the effectiveness, the method was applied to three rapidly developing Chinese cities: Beijing, Shanghai, and Chongqing with different natural and economic characteristics. The performance of the proposed method has been carefully evaluated with qualitative and quantitative analyses. Comparative experiments were also conducted across different datasets to prove the benefits of combining a social media check-in map with remotely sensed imagery in a human environment study.
•A method for identifying the structure of a polycentric city is proposed.•Advantages of nighttime light images and social media data are well integrated.•Timely monitoring and updating polycentric urban structure is made possible.•Segmentation of satellite images contributes to forming new statistical units.
Reactive oxygen species (ROS) are generated during mitochondrial oxidative metabolism as well as in cellular response to xenobiotics, cytokines, and bacterial invasion. Oxidative stress refers to the ...imbalance due to excess ROS or oxidants over the capability of the cell to mount an effective antioxidant response. Oxidative stress results in macromolecular damage and is implicated in various disease states such as atherosclerosis, diabetes, cancer, neurodegeneration, and aging. Paradoxically, accumulating evidence indicates that ROS also serve as critical signaling molecules in cell proliferation and survival. While there is a large body of research demonstrating the general effect of oxidative stress on signaling pathways, less is known about the initial and direct regulation of signaling molecules by ROS, or what we term the “oxidative interface.” Cellular ROS sensing and metabolism are tightly regulated by a variety of proteins involved in the redox (reduction/oxidation) mechanism. This review focuses on the molecular mechanisms through which ROS directly interact with critical signaling molecules to initiate signaling in a broad variety of cellular processes, such as proliferation and survival (MAP kinases, PI3 kinase, PTEN, and protein tyrosine phosphatases), ROS homeostasis and antioxidant gene regulation (thioredoxin, peroxiredoxin, Ref-1, and Nrf-2), mitochondrial oxidative stress, apoptosis, and aging (p66Shc), iron homeostasis through iron–sulfur cluster proteins (IRE–IRP), and ATM-regulated DNA damage response.
A novel temperature- and strain-independent optical fiber torsion sensor based on a phase-shifted fiber Bragg grating (PSFBG) inscribed by the line-by-line (LbL) technique in a standard single-mode ...fiber with a femtosecond laser has been proposed and experimentally demonstrated. The strong birefringence created by the LbL inscription technique leads to the significant polarization splitting of the transmission peak of the PSFBG. By simply monitoring the variation of the amplitude difference between the two polarization-peaks, the fiber torsion angle and the fiber torsion direction can be simultaneously deduced without temperature and strain confusion. The torsion sensor exhibits a high torsion sensitivity of up to -1032.71 dB/(rad/mm), with the distinct advantages of low manufacture cost, small dimension (just ~1.72mm), and extremely robust and simple structure, which make it very attractive for practical applications. To the best of our knowledge, this is the smallest torsion sensor ever reported.
This paper proposes a novel spatiotemporal fusion model for generating images with high-spatial and high-temporal resolution (HSHT) through learning with only one pair of prior images. For this ...purpose, this method establishes correspondence between low-spatial-resolution but high-temporal-resolution (LSHT) data and high-spatial-resolution but low-temporal-resolution (HSLT) data through the superresolution of LSHT data and further fusion by using high-pass modulation. Specifically, this method is implemented in two stages. In the first stage, the spatial resolution of LSHT data on prior and prediction dates is improved simultaneously by means of sparse representation; in the second stage, the known HSLT and the superresolved LSHTs are fused via high-pass modulation to generate the HSHT data on the prediction date. Remarkably, this method forms a unified framework for blending remote sensing images with temporal reflectance changes, whether phenology change (e.g., seasonal change of vegetation) or land-cover-type change (e.g., conversion of farmland to built-up area) based on a two-layer spatiotemporal fusion strategy due to the large spatial resolution difference between HSLT and LSHT data. This method was tested on both a simulated data set and two actual data sets of Landsat Enhanced Thematic Mapper Plus-Moderate Resolution Imaging Spectroradiometer acquisitions. It was also compared with other well-known spatiotemporal fusion algorithms on two types of data: images primarily with phenology changes and images primarily with land-cover-type changes. Experimental results demonstrated that our method performed better in capturing surface reflectance changes on both types of images.
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