In this communication, we propose using modern machine learning (ML) techniques including least absolute shrinkage and selection operator (lasso), artificial neural networks (ANNs), and ...<inline-formula> <tex-math notation="LaTeX">k </tex-math></inline-formula>-nearest neighbor (kNN) methods for antenna design optimization. The automated techniques are shown to provide an efficient, flexible, and reliable framework to identify optimal design parameters for a reference dual-band double T-shaped monopole antenna to achieve favorite performance in terms of its two bands, i.e., between 2.4 and 3.0 and 5.15 and 5.6 GHz. In this communication, we also present a thorough study and comparative analysis of the results predicted by these ML techniques, with the results obtained from high-frequency structure simulator (HFSS) to verify the accuracy of these techniques.
The modulation of electron density is an effective option for efficient alternative electrocatalysts. Here, p‐n junctions are constructed in 3D free‐standing FeNi‐LDH/CoP/carbon cloth (CC) electrode ...(LDH=layered double hydroxide). The positively charged FeNi‐LDH in the space‐charge region can significantly boost oxygen evolution reaction. Therefore, the j at 1.485 V (vs. RHE) of FeNi‐LDH/CoP/CC achieves ca. 10‐fold and ca. 100‐fold increases compared to those of FeNi‐LDH/CC and CoP/CC, respectively. Density functional theory calculation reveals OH− has a stronger trend to adsorb on the surface of FeNi‐LDH side in the p‐n junction compared to individual FeNi‐LDH further verifying the synergistic effect in the p‐n junction. Additionally, it represents excellent activity toward water splitting. The utilization of heterojunctions would open up an entirely new possibility to purposefully regulate the electronic structure of active sites and promote their catalytic activities.
The p‐n junction in FeNi‐LDH/CoP with positively charged FeNi‐LDH in the space‐charge region exhibits superior electro‐catalytical activity for the oxygen evolution reaction (OER). LDH=layered double hydroxide.
Graphene patchwork: A simple synthetic process requiring neither catalyst nor solvent was used to convert glucose directly into polycrystalline carbon sheets having a “patched” multidomain graphene ...structure with domains 2–15 nm in size. The carbon assemblies exhibit high conductivity, high specific surface area, and an unexpectedly good solution processability.
Direct hydrogenation of C=C double bonds is a basic transformation in organic chemistry which is vanishing from simple practice because of the need for pressurized hydrogen. Ammonia borane (AB) has ...emerged as a hydrogen source through its safety and high hydrogen content. However, in conventional systems the hydrogen liberated from the high‐cost AB cannot be fully utilized. Herein, we develop a novel Pd/g‐C3N4 stabilized Pickering emulsion microreactor, in which alkenes are hydrogenated in the oil phase with hydrogen originating from AB in the water phase, catalysed by the Pd nanoparticles at the interfaces. This approach is advantageous for more economical hydrogen utilization over conventional systems. The emulsion microreactor can be applied to a range of alkene substrates, with the conversion rates achieving >95 % by a simple modification.
What's in store? A Pd/graphitic carbon nitride (g‐C3N4) stabilized Pickering emulsion microreactor allows alkene hydrogenation using ammonia borane as the hydrogen source. This system can serve as a general hydrogen buffer space, leading to unit efficiency of hydrogen utilization. This emulsion microreactor provides more economical hydrogen utilization than conventional systems.
Water erosion is a time-varying processes controlled by both rainfall and overland flow. A better understanding of dynamic changes in the sediment load and size distribution with various erosive ...forces can help to develop and verify erosion models. Here, a total of 11 laboratory simulation experiments were conducted in a 1 m by 3 m flume with 3 storm rainfall intensities (60, 90, 120 mm h−1) and 2 inflow rates (5, 7.5 L min−1) on a silty clay red soil. Time-series measurements of the quantity and size distribution of eroded materials were made during 50 min rainfall/inflow time. The mean weight diameter of the effective sediment, sediment enrichment ratio, average stream power and rainfall power were measured and calculated. Fine sediment particles were associated with the short-lived initial stage, which was combined with sheet flow erosion and splash erosion, whereas coarse particles were associated with the rill development and rill stable stages, which were dominated by rill erosion and interrill erosion, respectively. The <0.05 mm aggregates were transported preferentially by the suspension/saltation mechanism, while 0.105–0.25 mm aggregates resisted transportation. Additionally, the sediment load rate showed a significant linear correlation with the stream power at the sheet flow (R2 = 0.84, p < 0.01) and rill development (R2 = 0.72, p < 0.01) stages as well as the rainfall power at the rill development (R2 = 0.76, p < 0.01) and rill stable stages (R2 = 0.78, p < 0.01). Sediment size increased with increasing stream power (p < 0.05) and rainfall power (p < 0.05) only at the rill development stage. The erosion processes play a major role in particle selection, and the erosion forms, aggregate breakdown and soil surface structure development should be considered for a more accurate prediction of size selectivity and the related sediment quality.
•Erosion processes were simulated under the combined effect of rainfall and overland flow.•The dynamic changes of sediment size distribution over time were affected by erosion forms.•Aggregates finer than 0.05 mm were transported preferentially by the suspension/saltation mechanism.•The relationships between erosion forces and sediment load changed with erosion process.
A simple but powerful chemical process—the copolymerization of biomass (glucose) and boric acid as templated by dicyandiamide (see picture)—was used to fabricate high‐quality doped graphene monoliths ...with through‐plane nanopores. The holey graphene monoliths had a high surface area and showed excellent performance as metal‐free carbocatalysts for selective oxidation.
Tumor‐associated neutrophils (TANs) play a crucial role in tumor development and progression in the cancer microenvironment. Despite increased understanding of TAN contributions to hepatocellular ...carcinoma (HCC) progression and prognosis, the direct interaction between TANs and HCC cells is not fully understood. In this study, we tested the effect of TANs on HCC cells in vitro and in vivo and investigated the mechanism of interaction between them. Our results showed that TANs secreted bone morphogenetic protein 2 and transforming growth factor beta 2 and triggered microRNA 301b‐3p (miR‐301‐3p) expression in HCC cells, subsequently suppressed gene expression of limbic system–associated membrane protein (LSAMP) and CYLD lysine 63 deubiquitinase (CYLD), and increased stem cell characteristics in HCC cells. These TAN‐induced HCC stem‐like cells were hyperactive in nuclear factor kappa B signaling, secreted higher levels of chemokine (C‐X‐C motif) ligand 5 (CXCL5), and recruited more TAN infiltration, suggesting a positive feedback loop. In clinical HCC samples, increased TANs correlated with elevated miR‐301b‐3p, decreased LSAMP and CYLD expression, and increased nuclear p65 accumulation and CXCL5 expression, all of which predicted patient outcome. Conclusion: Our work identified a positive feedback loop governing cancer stem‐like cells and TANs in HCC that controls tumor progression and patient outcome.
Lithium‐ion batteries are regarded as promising energy storage devices for next‐generation electric and hybrid electric vehicles. In order to meet the demands of electric vehicles, considerable ...efforts have been devoted to the development of advanced electrode materials for lithium‐ion batteries with high energy and power densities. Although significant progress has been recently made in the development of novel electrode materials, some critical issues comprising low electronic conductivity, low ionic diffusion efficiency, and large structural variation have to be addressed before the practical application of these materials. Surface and interface engineering is essential to improve the electrochemical performance of electrode materials for lithium‐ion batteries. This article reviews the recent progress in surface and interface engineering of electrode materials including the increase in contact interface by decreasing the particle size or introducing porous or hierarchical structures and surface modification or functionalization by metal nanoparticles, metal oxides, carbon materials, polymers, and other ionic and electronic conductive species.
Surface and interface engineering of electrodes is essential for the fabrication of high‐performance lithium‐ion batteries. A brief summary of the recent progress in surface and interface engineering of electrode materials is provided, and the effect of interface engineering on the electrochemical performance of different electrode materials is presented.
For high-temperature catalytic reaction, it is of significant importance and challenge to construct stable active sites in catalysts. Herein, we report the construction of sufficient and stable ...copper clusters in the copper‒ceria catalyst with high Cu loading (15 wt.%) for the high-temperature reverse water gas shift (RWGS) reaction. Under very harsh working conditions, the ceria nanorods suffered a partial sintering, on which the 2D and 3D copper clusters were formed. This partially sintered catalyst exhibits unmatched activity and excellent durability at high temperature. The interaction between the copper and ceria ensures the copper clusters stably anchored on the surface of ceria. Abundant in situ generated and consumed surface oxygen vacancies form synergistic effect with adjacent copper clusters to promote the reaction process. This work investigates the structure-function relation of the catalyst with sintered and inhomogeneous structure and explores the potential application of the sintered catalyst in C1 chemistry.
Heterogeneous catalysts of inexpensive and reusable transition-metal are attractive alternatives to homogeneous catalysts; the relatively low activity of transition-metal nanoparticles has become the ...main hurdle for their practical applications. Here, the de novo design of a Mott–Schottky-type heterogeneous catalyst is reported to boost the activity of a transition-metal nanocatalyst through electron transfer at the metal/nitrogen-doped carbon interface. The Mott–Schottky catalyst of nitrogen-rich carbon-coated cobalt nanoparticles (Co@NC) was prepared through direct polycondensation of simple organic molecules and inorganic metal salts in the presence of g-C3N4 powder. The Co@NC with controllable nitrogen content and thus tunable Fermi energy and catalytic activity exhibited a high turnover frequency (TOF) value (8.12 mol methyl benzoate mol–1 Co h–1) for the direct, base-free, aerobic oxidation of benzyl alcohols to methyl benzoate; this TOF is 30-fold higher than those of the state-of-the-art transition-metal-based nanocatalysts reported in the literature. The presented efficient Mott–Schottky catalyst can trigger the synthesis of a series of alkyl esters and even diesters in high yields.
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