高电压等级电压互感器综述

作为电力系统中广泛使用的设备,电压互感器与电力系统的安全稳定紧密相连。研究应对电压互感器故障的有效措施对保障电力系统的正常运行具有重要意义。文章选取在电力系统中普遍使用的电磁式电压互感器为研究对象,首先针对电磁式电压互感器出现的铁磁谐振故障、二次侧多点接地故障、回路断线故障和接线错误故障的机制及其危害进行了分析;然后,介绍了广泛应用的消谐措施的基本原理,深刻分析了其优缺点,并在此基础上介绍了传统措施的改进方法和能更好适应复杂情况的柔性消谐策略;最后,介绍了互感器多点接地、回路断线和接线错误的应对或防范措施。通过对各种故障处理方法的梳理,以期为研究电压互感器故障应对措施提供一定参考。     

新型人工胸壁修补网及人工肋骨织物的研制

针对当前临床上使用的人工胸壁之不足,研制出一种带人工肋骨的新型人工胸壁修补网结构,根据它们的结构及功能特点,设计了沿纬向带管道的人工胸壁修补网及三维编织人工肋骨织物的织造工艺。试织结果证明此织造工艺切实可行,所织成的人工胸壁已用于动物实验。     

聚甲基丙烯酸羟乙酯/乙二醛交联体系的溶液-凝胶-溶液转变研究

聚合物凝胶的溶液-凝胶（sol-gel）/凝胶-溶液（gel-sol）转变通常依赖于外界条件（温度、pH等）的变化，但构建可在恒定条件下实现sol-gel-sol转变的凝胶体系依然是一个挑战。本文基于聚甲基丙烯酸羟乙酯（PHEMA）、乙二醛（GX）和N,N-二甲基甲酰胺（DMF）成功构建了一种恒温自发随时间进行sol-gel-sol转变的聚合物凝胶体系（HGX）。通过改变GX的含量、温度等条件，可对HGX的成胶时间、凝胶强度及降解时间进行调控。结果表明，不同条件下HGX可在10~1500 min内形成弹性模量可达847 Pa的凝胶，然后在1.5 h到＞15 d后降解为低粘液体（＜30 mPa·s）。并利用红外光谱和凝胶色谱揭示了sol-gel-sol转变的内在机理是缩醛反应和酯基断键的动态竞争所致。     

Influence of dry- and wet-milled LLZTO particles on the sintered pellets

A Ta-doped Li₇La₃Zr₂O₁₂ (LLZTO) solid electrolyte is a promising candidate for all-solid-state lithium battery due to its high ionic conductivity and stability against lithium metal. In this work, physicochemical properties of both dry- and wet-milled LLZTO particles were investigated. Based on X-ray diffraction, Fourier transform–infrared, thermogravimetric analysis, and scanning electron microscopy results, it was confirmed that highly reactive LLZTO powder prepared in dry milling conditions exhibited faster size reduction, rougher surface morphology, fewer surface impurities, and less agglomerated particles, in contrast to those in wet milling conditions. Sintering these dry-milled powders at 1320°C for 10 min in the air via solid-state reaction produced dense ceramic pellets with a relative density of 97.4%. The room-temperature ionic conductivity for LLZTO pellet via the dry milling was determined to be 6.94 × 10⁻⁴ S cm⁻¹. Li–sulfur batteries based on the pellets showed an initial discharge capacity of 1301 mA h g⁻¹ and a coulombic efficiency of 99.82% when cycled at room temperature. The effect of the milled powder on the sintered pellets was discussed in terms of boundary mobility, pore mobility, and morphology.     

Universal Source-Template Route to Metal Selenides Implanting on 3D Carbon Nanoarchitecture: Cu2−xSe@3D-CN with Se?C Bonding for Advanced Na Storage

The development of high-performance sodium ion batteries (SIBs) is heavily relied on the exploration of the appropriate electrode material for Na⁺ storage, which ought to feature merits of high capacity, easy-to-handle synthesis, high conductivity, expedite mass transportation, and stable structure upon charging–discharging cycle. Herein, a universal source-template method is reported to synthesize a variety of transition metal (e.g., V, Sb, W, Zn, Fe, Co, Ni, and Cu) selenides implanting on N doped 3D carbon nanoarchitecture hybrids (M_mSe_n@3D-CN) with powerful Se C bonding rivet. Benefiting from the superior architecture and potent Se C bonding between Cu_2−xSe and N-doped 3D carbon (3D-CN), the Cu_2−xSe@3D-CN nanohybrids, as anode of SIBs, show high capacity, high-rate capability, and long-cycle durability, which can deliver a reversible capacity of as high as 386 mAh g⁻¹, retain 219 mAh g⁻¹ even at 10 A g⁻¹, and run durably over thousands of charging–discharging cycles. The Cu_2−xSe@3D-CN as anode is also evaluated by developing a full SIB by coupling with the Na₃V₂(PO₄)₃ cathode, which can deliver high energy density and show excellent stability, shedding light on its potential in practical application.     

再生粗骨料最大粒径对再生混凝土强度影响试验研究

为了研究再生粗骨料最大粒径对再生混凝土弯拉强度、抗压强度及折压比的影响程度，采用相同配合比下最大粒径为10、15、25和31 mm的再生粗骨料制备了4组再生混凝土棱柱体试件（100 mm×100 mm×400 mm）和4组立方体试件（100 mm×100 mm×100 mm），并通过试验获得了各组再生混凝土试块的弯拉强度和抗压强度。试验结果表明：相同水胶比下，再生混凝土弯拉强度及折压比均随再生粗骨料最大粒径的增大而减小，而抗压强度随再生粗骨料最大粒径的增大呈现出先增大而后减小的趋势。     

Alloyed Pt Single-Atom Catalysts for Durable PEM Water Electrolyzer

The high cost of noble metals is one of the key factors hindering the large-scale application of proton exchange membrane (PEM) water electrolyzer for hydrogen production. Recently, single-atom catalysts (SACs) with a potential of maximum atom utilization efficiency enable lowering the metal amount as much as possible; unfortunately, their durability remains a challenge under PEM water electrolyzer working conditions. Herein, a highly-stable alloyed Pt SAC is demonstrated through a plasma-assisted alloying strategy and applies to a PEM water electrolyzer. In this catalyst, single Pt atoms are firmly anchored onto a Ru support via a robust metal–metal bonding strength, as evidenced by these complementary characterizations. This SAC is used in a PEM water electrolyzer system to achieve a cell voltage as low as 1.8 V at 1000 mA cm⁻². Impressively, it can operate over 1000 h without obvious decay, and the catalyst is present in the form of individual Pt atoms. To the knowledge, this will be the first SAC attempt at a cell level toward long-term PEM. This work paves the way for designing durable SACs employed in the actual working condition in the PEM water electrolyzer.