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Electrochemical conversion of CO2 to formic acid using Bismuth catalysts is one the most promising pathways for industrialization. However, it is still difficult to achieve high formic acid production at wide voltage intervals and industrial current densities because the Bi catalysts are often poisoned by oxygenated species. Herein, we report a Bi3S2 nanowire-ascorbic acid hybrid catalyst that simultaneously improves formic acid selectivity, activity, and stability at high applied voltages. Specifically, a more than 95% faraday efficiency was achieved for the formate formation over a wide potential range above 1.0 V and at ampere-level current densities. The observed excellent catalytic performance was attributable to a unique reconstruction mechanism to form more defective sites while the ascorbic acid layer further stabilized the defective sites by trapping the poisoning hydroxyl groups. When used in an all-solid-state reactor system, the newly developed catalyst achieved efficient production of pure formic acid over 120 hours at 50 mA cm–2 (200 mA cell current). Achieving high pure formic acid production from CO2 electroconversion is of high interest yet challenging. Here the authors report vitamin C functionalized Bi3S2 nanowire catalyst to achieve selective, active, and stable formic acid production. [ABSTRACT FROM AUTHOR]

Catalysts with FeNC moieties have demonstrated remarkable activity toward oxygen reduction reaction (ORR), but precise synthesis and configuration regulation of FeNC to achieve bi‐functional catalytic sites for ORR and oxygen evolution reaction (OER) remain a great challenge. Herein, a pomegranate‐like catalyst with optimized FeN4 configuration is designed. The unique framework affords a large surface area for sufficient active site exposure and abundant macroporous channels for mass transport. By twisting chemical bonds, the electronic structure of FeN4 is regulated, and the adsorption/desorption of oxygen species is facilitated. Compared to noble metal‐based catalysts (Pt/C+IrO2), the optimized FeNC exhibits impressive onset potential (0.96 V versus reversible hydrogen electrode), larger limiting current density (5.85 mA cm−2), and better long‐term life for ORR, as well as, lower OER overpotential. When integrated into Zn‐air batteries, it demonstrates a respectable peak power density (71.6 mW cm−2) and ideal cycling stability (30 h), exceeding that of commercial Pt/C+IrO2. The exploration offers a guideline for designing advanced bi‐functional electrocatalysts. [ABSTRACT FROM AUTHOR]

Indirect bridge modal parameter identification using vehicle responses has been widely studied for two-dimensional bridge model, while rare work is devoted to the indirect identification of bridge spatial mode shape (BSMS). This paper proposes an effective procedure for BSMS identification of the widely used T-girder bridges, in which the closed-form solution is derived based on the vehicle contact-point response. The BSMS is identified using the bridge related components extracted from contact-point responses of a vehicle running at different transverse positions on the bridge. The detailed procedure for the identification of BSMS is introduced, and the feasibility of the method is analyzed numerically. To verify its applicability, the influences of some key factors in the vehicle–bridge system, such as the vehicle speed, the driving position, and the road surface roughness, on the identification results are analyzed. The effect of the bridge damage conditions on the BSMS identification is also investigated. The results show that the spatial mode shapes of T-girder bridges can be identified using the proposed method with high accuracy and efficiency. [ABSTRACT FROM AUTHOR]

This paper proposed an indirect bridge frequency identification and damage detection method based on the virtual contact-point (CP) responses of railway vehicles moving over the bridge. The virtual CP response is acquired to reduce the inverse effects of the track irregularity and vehicle dynamic components on the indirect bridge monitoring of the vehicle–bridge interaction (VBI) system. By combining the virtual CP responses of multiple connected vehicles, the first three bridge frequencies can be identified when vehicles run at high speed. The synchrosqueezing transform (SST) is then adopted to extract bridge-related dynamic components from the virtual CP response for bridge modal identification. The time-frequency (TF) representation of the virtual CP response using SST is further analyzed for bridge damage detection. The spectral entropy (SE) of the TF representation is introduced to quantify TF changes and serves as a damage index for bridge damage localization. Numerical studies are conducted to investigate the effects of measurement noise, damage conditions, and track irregularity on the effectiveness of the proposed method. The results demonstrate that SE is a good indicator for damage detection, and that the proposed method combined with wavelet denoising has good anti-noise performance and can well locate bridge damage using virtual CP response. [ABSTRACT FROM AUTHOR]

Developing efficient oxygen reduction reaction (ORR) catalyst is essential for the practical application of Zn‐air batteries (ZABs). In this contribution, we develop a novel zeolitic imidazolate framework (ZIF)‐mediated strategy to anchor Co species on N‐doped carbon nanorods for efficient ORR. Featuring ultrahigh N‐doping (10.29 at.%), monodisperse Co nanocrystal decoration, and well‐dispersed Co‐Nx functionalization, the obtained Co‐decorated N‐doped carbon nanorods (Co@NCNR) exhibit a decent ORR performance comparable to commercial Pt/C in alkaline media. Aqueous ZABs have been assembled using Co@NCNR as the cathode catalyst. The assembled ZABs manifest high initial open‐circuit voltage as well as high energy density. In addition, the Co@NCNR also demonstrates ideal ORR performance in quasi‐solid‐state ZABs. [ABSTRACT FROM AUTHOR]

To compare the biomechanical stability of slide compression anatomic plates of the femoral neck, cannulated compression screws and dynamic hip screws with derotation screws for stabilizing unstable femoral neck fractures (Pauwels angle = 70°). Pauwels III femoral neck fractures were created on 45 Sawbones femurs and randomly assigned to three implant groups (1:1:1). The biomechanical stability of all Sawbones in each treatment group was evaluated with three tests. First, in the static loading test, the load–displacement curve, vertical stiffness (load/vertical displacement [N/mm]) and 5 mm failure load were recorded. Second, in the incremental cyclic loading test (700, 1000, and 1400 N), the cyclic−displacement curve and the displacement of the fragments were recorded. Third, in the torsion test, the torsional rigidity, maximum torque, and torsional angle corresponding to the maximum torque were recorded. The static compression test showed that slide compression anatomic place‐femoral neck (SCAP‐FN) had the largest vertical stiffness (275 ± 11 N/mm, p < 0.01) and 5 mm failure load (1232 ± 156, p < 0.01). The cyclic loading test showed that SCAP‐FN had the lowest change in displacement after 30000 cycles of loading. The torsional stiffness and the maximum torque followed the order SCAP‐FN > dynamic hip screw systems (DHS) + derotational screw (DS) > CCS, and the torsional angle corresponding to the maximum torque followed the order SCAP‐FN < DHS + DS < CCS. The SCAP‐FN construct provides stiffness and stability compared with other standard fixation techniques (3CS and DHS + DS). The fixation strategy of SCAP‐FN might be sufficient for clinical use, indicating studies in the human body are warranted. [ABSTRACT FROM AUTHOR]