纳米零价铁在重金属污水高标准排放的应用

通过对某涉重工业园区污水处理厂重金属污水处理工艺的选择、试验验证及工程应用的论述,介绍纳米零价铁在重金属污水高标准排放的适用性及可行性,为类似污水处理厂的工艺选择、工程设计提供参考。     

南丹锡多金属矿床成因及成矿远景预测

广西南丹地区的锡多金属矿田是我国为数不多的超大型金属矿田之一,主要以产锡为主,还包括铜、锌、铅、锑、银等其他有色金属,还含有镓、铟等稀有金属。目前,较多的研究学者深入性的研究矿床的成因,并根据成因预测成矿远景,从而为我国挖掘出更多的有色金属,满足国家资源需求,推动我国经济快速发展。本文围绕金属矿床成因及成矿远景进行了研究,旨在为有色金属的开发提供有效的数据支持。     

含锰反萃液制备高纯碳酸锰工艺研究

以含锰反萃液为原料,经针铁矿法除铁、硫化除重金属、碳化、洗涤制备了合格高纯碳酸锰。考察了终点pH、反应温度对除铁率的影响和(NH4)2S加入量、温度、反应时间对重金属去除率的影响,结果表明:在pH=4.0、反应温度95℃的条件下可将铁除至1.5 mg/L以下;除铁滤液加入2.2倍计量比的(NH4)2S,在反应温度35℃、反应时间60 min的条件下,Ni、Co、Zn可降低至1 mg/L以下;除重金属滤液加入碳酸氢铵调节pH在7.0~7.2,过滤、洗涤,获得满足HG/T 2836—2011(Ⅰ型)产品标准的合格高纯碳酸锰,锰回收率为93.9%。     

有色冶炼氨氮废水脱氨系统设计与工业实践

对汽提精馏脱氨系统的物料平衡和热量平衡进行了理论计算,并将计算结果与有色冶炼工程案例中的运行指标进行了比较。结果表明,实际运行指标与理论计算结果一致,汽提精馏脱氨技术不仅能将废水氨氮去除至10 mg/L以下,还可回收浓度15%以上的氨水。     

铁基Cr—Mo—C—B系耐磨堆焊焊条的研制

针对高温磨损和磨粒磨损的工程条件,研制了具有良好堆焊工艺性和高温耐磨性的铁基Ｃｒ－Ｍｏ－Ｃ－Ｂ合金系堆焊焊条,在本试验条件下分析了Ｃｒ、Ｍｏ,Ｃ、Ｂ合金元素对堆焊层的组织、硬度和耐磨性的影响,并获得了最佳的堆焊层成分,在常温条件下,经搅拌机叶片堆焊后的现场应用,比耗损地片寿命提高３－４倍。     

Magnesium Science, Technology and Applications

The science, technology and applications of magnesium alloys are reviewed. The very low density of magnesium in combination with excellent castability is leading to increased use, despite poor galvanic corrosion resistance and a higher cost than aluminum, especially in automotive applications. Even further expansion of the magnesium market should come from an expanded design base, a better understanding of the scientific underpinning of magnesium alloys, and development of cost-affordable cast and wrought products.     

Ultrasoft Liquid Metal Elastomer Foams with Positive and Negative Piezopermittivity for Tactile Sensing

Soft, capacitive tactile (pressure) sensors are important for applications including human–machine interfaces, soft robots, and electronic skins. Such capacitors consist of two electrodes separated by a soft dielectric. Pressing the capacitor brings the electrodes closer together and thereby increases capacitance. Thus, sensitivity to a given force is maximized by using dielectric materials that are soft and have a high dielectric constant, yet such properties are often in conflict with each other. Here, a liquid metal elastomer foam (LMEF) is introduced that is extremely soft (elastic modulus 7.8 kPa), highly compressible (70% strain), and has a high permittivity. Compressing the LMEF displaces the air in the foam structure, increasing the permittivity over a large range (5.6–11.7). This is called “positive piezopermittivity.” Interestingly, it is discovered that the permittivity of such materials decreases (“negative piezopermittivity”) when compressed to large strain due to the geometric deformation of the liquid metal droplets. This mechanism is theoretically confirmed via electromagnetic theory, and finite element simulation. Using these materials, a soft tactile sensor with high sensitivity, high initial capacitance, and large capacitance change is demonstrated. In addition, a tactile sensor powered wirelessly (from 3 m away) with high power conversion efficiency (84%) is demonstrated.     

Liquid Metal Based Island‐Bridge Architectures for All Printed Stretchable Electrochemical Devices

The adoption of epidermal electronics into everyday life requires new design and fabrication paradigms, transitioning away from traditional rigid, bulky electronics towards soft devices that adapt with high intimacy to the human body. Here, a new strategy is reported for fabricating achieving highly stretchable “island‐bridge” (IB) electrochemical devices based on thick‐film printing process involving merging the deterministic IB architecture with stress‐enduring composite silver (Ag) inks based on eutectic gallium‐indium particles (EGaInPs) as dynamic electrical anchors within the inside the percolated network. The fabrication of free‐standing soft Ag‐EGaInPs‐based serpentine “bridges” enables the printed microstructures to maintain mechanical and electrical properties under an extreme (≈800%) strain. Coupling these highly stretchable “bridges” with rigid multifunctional “island” electrodes allows the realization of electrochemical devices that can sustain high mechanical deformation while displaying an extremely attractive and stable electrochemical performance. The advantages and practical utility of the new printed Ag‐liquid metal‐based island‐bridge designs are discussed and illustrated using a wearable biofuel cell. Such new scalable and tunable fabrication strategy will allow to incorporate a wide range of materials into a single device towards a wide range of applications in wearable electronics.     

Liquid Metal–Based Soft Microfluidics

Motivated by the increasing demand of wearable and soft electronics, liquid metal (LM)‐based microfluidics has been subjected to tremendous development in the past decade, especially in electronics, robotics, and related fields, due to the unique advantages of LMs that combines the conductivity and deformability all‐in‐one. LMs can be integrated as the core component into microfluidic systems in the form of either droplets/marbles or composites embedded by polymer materials with isotropic and anisotropic distribution. The LM microfluidic systems are found to have broad applications in deformable antennas, soft diodes, biomedical sensing chips, transient circuits, mechanically adaptive materials, etc. Herein, the recent progress in the development of LM‐based microfluidics and their potential applications are summarized. The current challenges toward industrial applications and future research orientation of this field are also summarized and discussed.     

Probing the Irregular Lattice Strain‐Induced Electronic Structure Variations on Late Transition Metals for Boosting the Electrocatalyst Activity

Owing to the simplicity in practice and continuous fine‐tuning ability toward the binding strengths of adsorbates, the strain effect is intensively explored, especially focused on the modulation of catalytic activity in transition metal (TM) based electrocatalysts. Recently, more and more abnormal cases have been found that cannot be explained by the conventional simplified models. In this work, the strain effects in five late TMs, Fe, Co, Ni, Pd, and Pt are studied in‐depth regarding the facet engineering, the surface atom density, and the d‐band center. Interestingly, the irregular response of Fe lattice to the applied strain is identified, indicating the untapped potential of achieving the phase change by precise strain modulation. For the complicated high‐index facets, the surface atom density has become the pivotal factor in determining the surface stability and electroactivity, which identifies the potential of high entropy alloys (HEA) in electrocatalysis. The work supplies insightful understanding and significant references for future research in subtle modulation of electroactivity based on the precise facet engineering in the more complex facets and morphologies.