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"Qian, Tao"
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Lithium anode stable in air for low-cost fabrication of a dendrite-free lithium battery
Lithium metal, the ideal anode material for rechargeable batteries, suffers from the inherent limitations of sensitivity to the humid atmosphere and dendrite growth. Herein, low-cost fabrication of a metallic-lithium anode that is stable in air and plated dendrite-free from an organic-liquid electrolyte solves four key problems that have plagued the development of large-scale Li-ion batteries for storage of electric power. Replacing the low-capacity carbon anode with a safe, dendrite-free lithium anode provides a fast charge while reducing the cost of fabrication of a lithium battery, and increasing the cycle life of a rechargeable cell by eliminating the liquid-electrolyte ethylene-carbonate additive used to form a solid-electrolyte interphase passivation layer on the anode that is unstable during cycling. This solution is accomplished by formation of a hydrophobic solid-electrolyte interphase on a metallic-lithium anode that allows for handling of the treated lithium anode membrane in a standard dry room during cell fabrication.
The lithium metal is a promising anode material for batteries; however, the growth of dendrite and its instability against moisture are two technical challenges. Here the authors address both issues by introducing a bifunctional layer consisting of hydrophobic graphite fluoride and lithium fluoride.
Journal Article
Salting-out effect promoting highly efficient ambient ammonia synthesis
The electroreduction of nitrogen to ammonia offers a promising alternative to the energy-intensive Haber–Bosch process. Unfortunately, the reaction suffers from low activity and selectivity, owing to competing hydrogen evolution and the poor accessibility of nitrogen to the electrocatalyst. Here, we report that deliberately triggering a salting-out effect in a highly concentrated electrolyte can simultaneously tackle the above challenges and achieve highly efficient ammonia synthesis. The solute ions exhibit strong affinity for the surrounding H
2
O molecules, forming a hydration shell and limiting their efficacy as both proton sources and solvents. This not only effectively suppresses hydrogen evolution but also ensures considerable nitrogen flux at the reaction interface via heterogeneous nucleation of the precipitate, thus facilitating the subsequent reduction process in terms of both selectivity and activity. As expected, even when assembled with a metal-free electrocatalyst, a high Faradaic efficiency of 71 ± 1.9% is achieved with this proof-of-concept system.
The electroreduction of nitrogen to ammonia offers a promising alternative to the Haber–Bosch process but suffers from low activity and selectivity. Here, authors demonstrate that triggering a salting-out effect in a highly concentrated electrolyte can achieve highly efficient ammonia synthesis.
Journal Article
Over 56.55% Faradaic efficiency of ambient ammonia synthesis enabled by positively shifting the reaction potential
Ambient electrochemical N
2
reduction is emerging as a highly promising alternative to the Haber–Bosch process but is typically hampered by a high reaction barrier and competing hydrogen evolution, leading to an extremely low Faradaic efficiency. Here, we demonstrate that under ambient conditions, a single-atom catalyst, iron on nitrogen-doped carbon, could positively shift the ammonia synthesis process to an onset potential of 0.193 V, enabling a dramatically enhanced Faradaic efficiency of 56.55%. The only doublet coupling representing
15
NH
4
+
in an isotopic labeling experiment confirms reliable NH
3
production data. Molecular dynamics simulations suggest efficient N
2
access to the single-atom iron with only a small energy barrier, which benefits preferential N
2
adsorption instead of H adsorption via a strong exothermic process, as further confirmed by first-principle calculations. The released energy helps promote the following process and the reaction bottleneck, which is widely considered to be the first hydrogenation step, is successfully overcome.
While direct N
2
reduction using electrochemistry offers an appealing method to obtain usable nitrogen, materials typically show poor activities and efficiencies. Here, authors demonstrate a single-atom catalyst, iron on N-doped carbon, to have dramatically enhanced N
2
reduction efficiencies.
Journal Article
Facilitating nitrogen accessibility to boron-rich covalent organic frameworks via electrochemical excitation for efficient nitrogen fixation
Covalent organic frameworks with abundant active sites are potential metal-free catalysts for the nitrogen reduction reaction. However, the utilization ratio of active sites is restricted in an actual reaction process due to the limited nitrogen transport. Here, we demonstrate that facilitating the N
2
accessibility to boron-rich covalent organic frameworks through electrochemical excitation can achieve highly efficient nitrogen reduction activity. Simulations show that the boron sites are bonded with nitrogenous species under electrochemical condition and the resultant amorphous phase of covalent organic frameworks has much stronger affinity toward N
2
to enhance the molecule collision. Combined with experimental results, the excitation process is confirmed to be a virtuous cycle of more excited sites and stronger N
2
affinity, which continuously proceed until the whole system reaches the optimum reaction status. As expected, the electrochemically excited catalyst delivers significantly enhanced reaction activity, with a high Faradaic efficiency of 45.43%.
Covalent organic frameworks are potential catalysts for nitrogen reduction, but limited nitrogen transport restricts the utilization ratio of active sites. Here, the authors demonstrate that electrochemical excitation of covalent organic frameworks can lead to efficient nitrogen reduction.
Journal Article
Nasopharyngeal carcinoma: an evolving paradigm
The past three decades have borne witness to many advances in the understanding of the molecular biology and treatment of nasopharyngeal carcinoma (NPC), an Epstein–Barr virus (EBV)-associated cancer endemic to southern China, southeast Asia and north Africa. In this Review, we provide a comprehensive, interdisciplinary overview of key research findings regarding NPC pathogenesis, treatment, screening and biomarker development. We describe how technological advances have led to the advent of proton therapy and other contemporary radiotherapy approaches, and emphasize the relentless efforts to identify the optimal sequencing of chemotherapy with radiotherapy through decades of clinical trials. Basic research into the pathogenic role of EBV and the genomic, epigenomic and immune landscape of NPC has laid the foundations of translational research. The latter, in turn, has led to the development of new biomarkers and therapeutic targets and of improved approaches for individualizing immunotherapy and targeted therapies for patients with NPC. We provide historical context to illustrate the effect of these advances on treatment outcomes at present. We describe current preclinical and clinical challenges and controversies in the hope of providing insights for future investigation.Nasopharyngeal carcinoma (NPC) is an Epstein–Barr virus (EBV)-associated malignancy endemic to southern China, southeast Asia and north Africa. The authors of this Review present a comprehensive overview of advances from the past three decades on the pathogenic role of EBV, and the genomic, epigenomic and immune landscape of NPC, which have led to the development of new biomarkers, therapeutic targets and improved treatment approaches for patients with NPC.
Journal Article
Blood Flow of Au-Nanofluid Using Sisko Model in Stenotic Artery with Porous Walls and Viscous Dissipation Effect
Nanofluids are extremely useful to investigators due to their greater heat transfer rates, which have significant applications in multiple industries. The primary objective of this article is to look into the effect of viscous dissipation in Sisko nano liquid flow with gold Au nanoparticles on a porous stenosis artery. Heat transfer properties were explored. Blood was utilized as a base fluid for nanoparticles. To renovate the governing nonlinear PDEs into nonlinear ODEs, appropriate transformations were used. The bvp4c-based shooting method, via MATLAB, was used to determine the numerical results of the nonlinear ODEs. Furthermore, flow forecasts for each physical quantity were explored. To demonstrate the physical influences of flow constraints versus presumed flow fields, physical explanations were used. The findings demonstrated that the velocity contour improved as the volume fraction, curvature, power law index, and material parameter upsurged. For the Prandtl number, the volume fraction of nanoparticles, the index of the power law, and the temperature profile of the nanofluid declined. Furthermore, the drag force and transfer of the heat were also investigated as explanations for influences on blood flow. Further, the Nusselt number reduced and the drag force enhanced as the curvature parameter values increased. The modeling and numerical solutions play an impressive role in predicting the cause of atherosclerosis.
Journal Article
Where does fear originate in the brain? A coordinate-based meta-analysis of explicit and implicit fear processing
Processing of fear is of crucial importance for human survival and it can generally occur at explicit and implicit conditions. It is worth noting that explicit and implicit fear processing produces different behavioral and neurophysiological outcomes. The present study capitalizes on the Activation Likelihood Estimation (ALE) method of meta-analysis to identify: (a) the “core” network of fear processing in healthy individuals; (b) common and specific neural activations associated with explicit and implicit processing of fear. Following PRISMA guidelines, a total of 92 fMRI and PET studies were included in the meta-analysis. The overall analysis show that the core fear network comprises the amygdala, pulvinar, and fronto-occipital regions. Both implicit and explicit fear processing activated amygdala, declive, fusiform gyrus, and middle frontal gyrus, suggesting that these two types of fear processing share a common neural substrate. Explicit fear processing elicited more activations at the pulvinar and parahippocampal gyrus, suggesting visual attention/orientation and contextual association play important roles during explicit fear processing. In contrast, implicit fear processing elicited more activations at the cerebellum-amygdala-cortical pathway, indicating an ‘alarm’ system underlying implicit fear processing. These findings have shed light on the neural mechanism underlying fear processing at different levels of awareness.
Journal Article
Aggregation‐induced delayed electrochemiluminescence of organic dots in aqueous media
Full utilization of the excited species at both singlet states (1R*) and triplet states (3R*) is crucial to improving electrochemiluminescence (ECL) efficiency but is challenging for organic luminescent materials. Here, an aggregation‐induced delayed ECL (AIDECL) active organic dot (OD) containing a benzophenone acceptor and dimethylacridine donor is reported, which shows high ECL efficiency via reverse intersystem crossing (RISC) of non‐emissive 3R* to emissive 1R*, overcoming the spin‐forbidden radiative decay from 3R*. By introducing dual donor‐acceptor pairs into luminophores, it is found that nonradiative pathway could be further suppressed via enhanced intermolecular weak interactions, and multiple spin‐up conversion channels could be activated. As a consequence, the obtained OD enjoys a 6.8‐fold higher ECL efficiency relative to the control AIDECL‐active OD. Single‐crystal studies and theoretical calculations reveal that the enhanced AIDECL behaviors come from the acceleration of both radiative transition and RISC. This work represents a major step towards purely organic, high‐efficiency ECL dyes and a direction for the design of next‐generation ECL dyes at the molecular level. Aggregation‐induced delayed electrochemiluminescence (AIDECL) is proposed for the first time, which allows the utilization of the non‐radiative triplet excited species to emit light via reverse intersystem crossing. Molecular design principles are presented for the exploitation of AIDECL‐active organic dots with high electrochemiluminescence efficiency in aqueous media.
Journal Article
Analysis of the dynamics of a vector-borne infection with the effect of imperfect vaccination from a fractional perspective
The burden of vector-borne infections is significant, particularly in low- and middle-income countries where vector populations are high and healthcare infrastructure may be inadequate. Further, studies are required to investigate the key factors of vector-borne infections to provide effective control measure. This study focuses on formulating a mathematical framework to characterize the spread of chikungunya infection in the presence of vaccines and treatments. The research is primarily dedicated to descriptive study and comprehension of dynamic behaviour of chikungunya dynamics. We use Banach’s and Schaefer’s fixed point theorems to investigate the existence and uniqueness of the suggested chikungunya framework resolution. Additionally, we confirm the Ulam–Hyers stability of the chikungunya system. To assess the impact of various parameters on the dynamics of chikungunya, we examine solution pathways using the Laplace-Adomian method of disintegration. Specifically, to visualise the impacts of fractional order, vaccination, bite rate and treatment computer algorithms are employed on the infection level of chikungunya. Our research identified the framework’s essential input settings for managing chikungunya infection. Notably, the intensity of chikungunya infection can be reduced by lowering mosquito bite rates in the affected area. On the other hand, vaccination, memory index or fractional order, and treatment could be used as efficient controlling variables.
Journal Article