A class of 2D covalent organic polymers (COPs) incorporating a metal (such as Fe, Co, Mn) with precisely controlled locations nitrogen heteroatoms and holes were synthesized from various N-containing metal-organic complexes (for example, metal-porphyrin complexes) by nickel-catalyzed Yamamoto reaction. Subsequent carbonization the metal-incorporated COPs led to formation COP-derived graphene analogues, which acted efficient electrocatalysts for oxygen reduction in both alkaline acid media...

Using covalent organic polymer pre­cursors, we have developed a new strategy for location control of N-dopant heteroatoms in the graphitic porous carbon, which otherwise is impossible to achieve with conventional N-doping techniques. The electrocatalytic activities N-doped holey graphene analogues are well correlated N-locations, showing possibility tailoring structure and property carbon nanomaterials. As service our authors readers, this journal provides supporting information supplied by...

Abstract A membrane with both high ion conductivity and selectivity is critical to power density low-cost flow batteries, which are of great importance for the wide application renewable energies. The trade-off between a bottleneck conductive membranes. In this paper, thin-film composite ultrathin polyamide selective layer found break conductivity, dramatically improve battery. As result, vanadium battery achieves energy efficiency higher than 80% at current 260 mA cm −2 , highest ever...

Abstract A dual temperature‐ and light‐responsive C 2 H /C 4 separation switch in a diarylethene metal–organic framework (MOF) is presented. At 195 K 100 kPa this MOF shows ultrahigh selectivity of 47.1, which almost 21.4 times larger than the corresponding value 2.2 at 293 kPa, or 15.7 3.0 for material under UV kPa. The origin unique control selectivity, as unveiled by density functional calculations, due to guest discriminatory gate‐opening effect from unit.

This article presents the design of a novel low-profile ultrawideband textile antenna for wearable microwave medical imaging systems. The proposed is based on monopole structure, where two triangles and few parallel slots are cut at bottom corners top edge radiation patch, respectively, to achieve an optimized ultrawide bandwidth reduced size antenna. Polyester fabrics conductive copper taffeta, which universally available market, selected construct Thus, fabricated prototypes well suit...

Dielectric resonance tuning could improve the electromagnetic wave absorption (EMA) properties of materials; however, current strategies for dielectric are scarcely reported.

Because of crystal symmetry, body centred cubic (BCC) metals have large differences in lattice friction between screw and edge dislocations, manifest generally different mechanical behaviours from face (FCC) metals. Although annealing (significant drop stored dislocation density response to applied stress) has been observed FCC metals, it not BCC so far. Here we show that significant does occur Mo pillars, when their diameters decrease hundreds nanometers. In addition, there exists a...

This work describes the design of a new graphite-like carbon nitride material, g-C₃N₅, and found that g-C₃N₅ exhibits promising applications in metal-free ORR electrocatalysis, photocatalysis CO₂ capture.

Graphical Abstract The trend from “smaller is stronger” to “size-independent strength plateau” observed in the compression of spherical iron nanoparticles. When diameter nanospheres less than a critical value, maximum contact pressure saturates at 10.7 GPa, corresponding local shear stress ≈9.4 which comparable theoretical iron.

Essential oils have been evaluated as appropriate phytotoxins with mechanisms of action that are different from those synthetic herbicides applied in weed management activities, but little is known about the effect Ambrosia artemisiifolia essential oil (EO) on weeds. Here, chemical composition A. EO was analyzed using a Gas Chromatography-Mass Spectrometry system. and phytotoxic activities against monocot (Poa annua, Setaria viridis) dicot (Amaranthus retroflexus, Medicago sativa) species...

Uniform and well-dispersed SrF2 hierarchical microspheres have been successfully synthesized by a facile friendly hydrothermal method. The experimental results indicate that such 3D with size about 1 μm are assembled numerous nanocrystals (about 100 nm). Nitrogen adsorption−desorption measurement suggests mesopores exist in these microarchitectures. formation process of the luminescence properties SrF2:Ln3+ (Ln = Ce, Tb, Yb, Er) investigated detail. It is found reaction time trisodium...

In this paper, a new high-resolution approach called fourth-order cumulants-based Toeplitz matrices reconstruction (FOC-TMR) method, is presented for two-dimensional (2-D) direction-of-arrival (DOA) estimation of incident narrowband coherent signals. The angle problem addressed by arranging the cumulants elements received signals from two parallel uniform linear arrays (ULAs) to matrices. Gaussian noise cases, it shown that ranks equal number incoming waves and are independent their...

The “dual-cycle” pathway (i.e., olefin-based cycle and aromatic-based cycle) of methanol-to-olefin (MTO) has been generally accepted as hydrocarbon pool mechanism. Understanding the role diffusion reactant, intermediate, product in MTO process is essential revealing its reaction By using molecular dynamics (MD) simulations for two one-dimensional zeolites (ZSM-12 ZSM-22) with a channel difference being only 0.3 Å pore size, behaviors some representative species following mechanism (e.g.,...

Abstract A class of 2D covalent organic polymers (COPs) incorporating a metal (such as Fe, Co, Mn) with precisely controlled locations nitrogen heteroatoms and holes were synthesized from various N‐containing metal–organic complexes (for example, metal–porphyrin complexes) by nickel‐catalyzed Yamamoto reaction. Subsequent carbonization the metal‐incorporated COPs led to formation COP‐derived graphene analogues, which acted efficient electrocatalysts for oxygen reduction in both alkaline acid...

Exceptional selectivity and high adsorption capacity for xenon have been realized by simultaneously introducing plenty of narrow pores engineering the pore surface with sulfonic functionality.

Abstract Oxygen reduction reaction plays a crucial role in energy‐related devices. However, four‐electron transfer process involved this is usually constrained by sluggish kinetics. Single atomic (SA) Fe catalysts have attracted extensive attention due to the high atom utilization, yet impact of support architecture on accelerating has been largely overlooked. Inspired edge‐rich and ordered tile that facilitates rainwater runoff, an orderly stacked “tile” carbon with highly dispersed SA...

In this paper, we combine the multiple-input-multiple-output (MIMO) array antenna technology with a multipolarization component in ground penetrating radar (GPR) system to improve target detection accuracy. The MIMO introduced previous literature is widely applied and other wireless communication fields. Here, apply "plane-wave like" (PWL) source that uses antennas small spacing emit pulse at same time GPR detection. First, analyze physical mechanism of "PWL" resolution. Then, carry out...

In this paper we introduce an end-to-end deep learning (DL) framework for magnetic anomaly detection (MAD) and denoising. This consists of two neural networks: a binary classification network regression geomagnetic noise suppression. The networks work in cascade mode: the field measurement is first sent to check existence signal, then denoising extracting signal from if result positive. core idea our proposed method that characteristics both can be learned massive training data. experimental...

Biomass-derivatives, e.g., furfural, have been widely reported to become new-generation renewable sources of chemicals and fuels. However, it is too complicated understand the product selectivity furfural conversion in diverse reactions. Accordingly, by using density functional theory calculations, both hydrodeoxygenation decarboxylation on Ni(111) surface form furan, 2-methylfuran, furfuryl alcohol, tetrahydrofuran, tetrahydrofurfuryl alcohol thoroughly investigated. On basis minimum energy...