Durable Integrated K-Metal Anode with Enhanced Mass Transport through Potassiphilic Porous Interconnected Mediator

K-metal batteries have become one of the promising candidates for the large-scale energy storage owing to the virtually inexhaustible and widely potassium resources. The uneven K⁺ deposition and dendrite growth on the anode causes the batteries prematurely failure to limit the further application. An integrated K-metal anode is constructed by cold-rolling K metal with a potassiphilic porous interconnected mediator. Based on the experimental results and theoretical calculations, it demonstrates that the potassiphilic porous interconnected mediator boosts the mass transportation of K-metal anode by the K affinity enhancement, which decreases the concentration polarization and makes a dendrite-free K-metal anode interface. The interconnected porous structure mitigates the internal stress generated during repetitive deposition/stripping, enabling minimized the generation of electrode collapse. As a result, a durable K-metal anode with excellent cycling ability of exceed 1, 000 h at 1 mA cm⁻²/1 mAh cm⁻² and lower polarization voltage in carbonate electrolyte is obtained. This proposed integrated anode with fast K⁺ kinetics fabricated by a repeated cold rolling and folding process provides a new avenue for constructing a high-performance dendrites-free anode for K-metal batteries.     

Non-Platinum Group Metal Electrocatalysts toward Efficient Hydrogen Oxidation Reaction

Developing non-platinum group metal (non-PGM) electrocatalysts for the hydrogen oxidation reaction (HOR) represents the efforts towards the more economical use of hydrogen fuel cells and hydrogen energy, which has attracted tremendous attention recently. However, non-PGM electrocatalysts for the HOR are still in their early development stages as compared with the significant advances in those for the oxygen reduction reaction and hydrogen evolution reaction. Herein, this paper summarizes the recent progresses and highlights the key challenges for the rational design of non-PGM electrocatalysts, aiming to promote the development of non-PGM HOR electrocatalysts. Fundamental understandings of the HOR mechanism are firstly reviewed, where theoretical interpretations on the low HOR kinetics in alkaline media, including the hydrogen binding energy theory, the bifunctional mechanism, and the water molecule reorganization, are particularly discussed. Subsequently, progresses of typical non-PGM HOR electrocatalysts in acid and alkaline media are summarized separately. For the HOR under alkaline conditions, the superiorities and challenges of Ni-based catalysts are discussed with a particular focus as they are the most promising non-PGM electrocatalysts. Finally, this paper highlights the challenges and provide perspectives on the future development directions of non-PGM HOR electrocatalysts.     

稠油黏度影响因素研究进展

分析了稠油的黏温性质及流变特性,讨论了稠油黏度的影响因素,稠油胶体体系中由胶质、沥青质缔合形成的大分子聚集体是造成稠油高黏的根本原因,而过渡金属元素(Ni,V等)及杂原子(S,N,O等)在胶质、沥青质中的富集是缔合的主要原因。     

高阻尼合金在兵器上的潜在应用

高阻尼合金是一种新型合金材料。它用于结构件时具有明显的降噪减震效果。文中简述了该种合金的发展过程，分类和工作原理，并对其在兵器工业上的潜在应用进行了探讨。     

淮南采煤沉陷区积水重金属健康风险评价

为研究淮南采煤沉陷区积水中重金属对人体产生的潜在健康风险,对9个矿19个沉陷水域进行采样,测试5种重金属(Cd、Cr、Pb、Ni、Zn)含量,采用美国环境保护局(USEPA)推荐使用的健康风险评价模型,对其进行健康风险评价。研究结果表明：(1)采样水域5种重金属年平均离子浓度由大到小依次为：Zn＞Cr＞Ni＞Pb＞Cd,重金属的分布影响因素可能与农药化肥的使用、工业废水的排放、汽车尾气中重金属的大气沉降、渔业养殖以及采煤活动等因素有关;(2)重金属的健康风险值总体随季节变化,呈现出丰水期小于枯水期的特点;该区域沉陷积水的重金属致癌风险整体较为安全,但化学致癌物(Cr)的健康风险值超出其它4种重金属4~8个数量级;(3)5种重金属的健康风险平均值排序为：Cr＞Cd＞Pb＞Zn＞Ni,其中Cd的致癌风险值及Pb、Zn、Ni非致癌风险值均低于最大可接受风险值(5.05×10-5a-1)。     

纳米油墨在电子工业中的应用

纳米油墨在许多行业得到推广应用,如防伪印刷、包装印刷、纺织品印花、电子线路层印刷等,都有效地提高了产品质量和性能。文章主要介绍纳米油墨在电子工业的应用前景。     

p型金刚石欧姆接触的研究

金刚石的欧姆接触是制造半导体器接触的研究进展,结合器件的发展和实际工艺的要求,讨论了改善欧姆接触特性的途径和方法,指出目前存在急需解决的一些问题.     

应用激光诱导击穿光谱测量水体中痕量重金属锌

利用激光诱导击穿光谱(LIBS)对水体中痕量重金属锌进行定性及定量分析,以1064nm波长Nd…YAG脉冲激光为激发光源,采用高分辨率、宽光谱段的中阶梯光栅光谱仪和增强型电荷耦合器件(ICCD)为谱线分离与探测器件,以锌(Zn:481.1nm)特征谱线作为分析线,测定不同浓度下的特征谱线强度。实验中以固体圆饼状石墨块为样品基体进行元素富集,滴定固定量的已知不同浓度的氯化锌溶液于基体表面固定区域,烘干并制备实验待测样品。结果表明,锌的最佳探测延迟时间为1100ns,元素谱线强度随着样品浓度的增加而增大并在较低浓度下呈线性关系,得到水体中锌元素的痕量检测限4.108mg/L。研究结果为进一步开展水体痕量重金属的激光诱导击穿光谱测量提供了方法。     

Nanoporous Surface High-Entropy Alloys as Highly Efficient Multisite Electrocatalysts for Nonacidic Hydrogen Evolution Reaction

Electrocatalytic hydrogen evolution in alkaline and neutral media offers the possibility of adopting platinum-free electrocatalysts for large-scale electrochemical production of pure hydrogen fuel, but most state-of-the-art electrocatalytic materials based on nonprecious transition metals operate at high overpotentials. Here, a monolithic nanoporous multielemental CuAlNiMoFe electrode with electroactive high-entropy CuNiMoFe surface is reported to hold great promise as cost-effective electrocatalyst for hydrogen evolution reaction (HER) in alkaline and neutral media. By virtue of a surface high-entropy alloy composed of dissimilar Cu, Ni, Mo, and Fe metals offering bifunctional electrocatalytic sites with enhanced kinetics for water dissociation and adsorption/desorption of reactive hydrogen intermediates, and hierarchical nanoporous Cu scaffold facilitating electron transfer/mass transport, the nanoporous CuAlNiMoFe electrode exhibits superior nonacidic HER electrocatalysis. It only takes overpotentials as low as ≈240 and ≈183 mV to reach current densities of ≈1840 and ≈100 mA cm⁻² in 1 m  KOH and pH 7 buffer electrolytes, respectively; ≈46- and ≈14-fold higher than those of ternary CuAlNi electrode with bimetallic Cu–Ni surface alloy. The outstanding electrocatalytic properties make nonprecious multielemental alloys attractive candidates as high-performance nonacidic HER electrocatalytic electrodes in water electrolysis.