Stretchable,Antifreezing, Non-Drying,and Fast-Response Sensors Based on Cellulose Nanocomposite Hydrogels for Signal Detection

Conductive hydrogels have received widespread attention in the applications of biosensors, human–machine interface, and health recording electrodes. Herein, the conductive hydrogels integrated with antifreezing, water retention, reusable, and sensing performances are fabricated by introducing polyvinyl alcohol, cellulose nanofibril, MXene nanosheets, and glycerol. The as-prepared hydrogels present prominent electrical conductivity (2.58 mS cm⁻¹) and flexibility even at −18 °C. In addition, the hydrogels have favorable water retention performance and can reuse after heating and cooling. When used as sensors, the hydrogels illustrate high sensitivity (gauge factor of 2.30), fast response time (0.165 s), wide working strain range (559%), favorable linearity (R² = 0.999), and wide operating temperature range (−18 to 60 °C). The hydrogels can detect not only large strains of 10–200%, but also small strains of 1–5%, making them promising candidates for wearable sensors to monitor large and subtle movements.     

Effect of high temperature on the mechanical properties of hierarchical porous cenosphere/geopolymer composite foams

A hierarchical porous cenosphere/geopolymer composite foam (FHCs/KGP) was fabricated by the simultaneous incorporation of O₂ pore from hydrogen peroxide and cenosphere filler addition. Effects of both H₂O₂ content and high-temperature treatment on the microstructure, porosity and strength of porous FHCs/KGP foams were investigated systematically. The obtained FHCs/KGP foams showed typical amorphous structure and desirable porosity from 65 to 82%. The composites could crystallize in situ to FHCs/leucite foams above 1000℃. Compression strength of the FHCs/leucite foams showed a maximum value of 5 ± 0.3 MPa when treated at 1000°C. The improvement of mechanical properties for the composite foams was attributed to crack deflection, fractured microspheres and the good bond between the FHCs and matrix. This study could open opportunities to employ cellular foams as alternatives in structure and filtration applications.     

Improvement of flexural bond strength of zirconia-resin cement by surface patterning using sub-nanosecond UV laser

Zirconia is a dental material that shows excellent biocompatibility and high strength in clinical applications. This study aims to evaluate the effects of ultrafast laser applications. The surface nanostructures were classified into three groups. Group 1 was generated using the burst mode, with three different distances between dots: 52 µm (Group 1a), 104 µm (Group 1b), and 156 µm (Group 1c). Group 2 was processed using the scanning mode configuration, with a set of parallel lines. Group 3 was also processed using this scanning configuration creating a set of square-shaped patterning. Group 4 was the control group. After the surface treatments, a pair of zirconia specimens was bonded end to end with resin cement. Flexural bond strength (FBS) test was applied in a universal test machine. Multiple comparisons were performed using a one-way analysis of variance and the Tukey's HSD test. All the samples that were treated with the laser showed higher FBS values than the untreated surface. Using the burst mode, preformed circular-shaped surface on an angle of 90⁰ at 52 µm distance (Group 1a) showed the highest FBS values among all groups (p < .05). Groups 2 and 3 had significantly higher values than 1b and 1c.     

The effect of heat treatment on tensile properties of 2D C/SiC composites

Two-dimensional (2D) carbon fiber reinforced silicon carbide (C/SiC) composites with different initial strength were prepared by chemical vapor infiltration (CVI). After tensile property testing, results exhibited that as the heat-treatment temperature (HTT) increases to 1900°C, the tensile strength and toughness of the low strength specimen (LSS) increased by 110% and 530%, while the high strength specimen (HSS) increased by 5.4% and 550%, respectively. As observed from morphologies, the heat treatment increases the graphitization of the amorphous PyC interphase, which leads to the weakening of interfacial bonding strength (IBS). Meanwhile, the defects arising from heat treatment cause thermal residual stress relaxation. Therefore, the tensile strength and toughness of LSS with relatively high initial IBS increase significantly as HTT increases. For HSS with moderate initial IBS, the heat treatment slightly improves the tensile strength, but significantly improves the toughness. Consequently, the post-heat-treatment tensile properties of 2D C/SiC composites can be regulated by varying HTTs and different initial strength.     

非贵金属电解水催化剂改性研究进展

氢能作为理想的二次能源,具有能量密度高、清洁无污染等特点,在能源转型过程中将发挥极为重要的作用。电解水制氢被认为是获取氢能最有潜力的绿色工艺,而高效电催化剂是制约电解水制氢快速发展的关键。贵金属催化剂具有优良的电催化性能,但由于成本和储量问题严重限制其推广应用,因而开发低成本高活性的非贵金属催化剂逐渐成为研究热点。为提高非贵金属催化剂的电催化性能,需要对其进行一系列的改性优化工作。综述了近几年国内外非贵金属电解水催化剂的改性研究进展,详细介绍了几何构造（一维、二维、三维结构）和电子调控（组成优化、晶面调控、缺陷构造、杂原子掺杂等）两种非贵金属催化剂的改性方法,并对今后非贵金属电解水催化剂改性发展方向进行了展望。     

磁性金属有机框架材料制备及吸附性能研究

利用简单的溶剂热法合成了MIL-101（Fe）/CoFe₂O₄和MIL-101（Fe）/NiFe₂O₄磁性金属有机框架纳米复合材料。通过X射线衍射仪（XRD）、扫描电子显微镜（SEM）、振动磁强计（VSM）、热重分析仪（TGA）和紫外可见分光光度计（UV）等对复合材料的相结构、形貌、磁性能和吸附性能进行了研究。将磁性金属有机框架材料用于吸附污水中罗丹明B（RhB）,研究了罗丹明B初始质量浓度对复合材料吸附能力的影响。结果表明,制备的磁性金属有机框架复合材料的形貌均匀、结晶度高,具有高的饱和磁化强度。复合物具有金属有机框架材料和磁性材料的双重优点。MIL-101（Fe）/CoFe₂O₄对罗丹明B有较高的吸附能力（97.3 mg/g）。热力学研究发现吸附等温方程符合Langmuir模型,吸附动力学研究表明吸附机制与吸附质和吸附剂有关。磁性金属有机框架纳米复合材料作为污水处理剂将具有广阔的应用前景。     

Microstructure evolution of cold-sprayed coating during deposition and through post-spraying heat treatment

The microstructural features of cold-sprayed coatings were investigated using Cu, Ti and Zn feedstocks by optical microscopy, scanning electron microscopy and transmission electron microscopy to reveal the microstructure evolution mechanisms in cold spray. Four typical effects including tamping, refinement, impact-induced fusion and annealing were examined on microstrueture. It is found that the microstructure of cold spray coating is remarkably influenced by spray materials. Ti coatings consist of evident porous layer and Cu coatings present a limited porous layer only near the surface. It is clear that the successive tamping effect and dynamic refinement of grains significantly influence the microstructure evolution of cold-sprayed coating. The tamping effect leads to the densification of porous coating layer gradually and the refinement effect leads to the formation of fine microstructure. It is considered that the large difference in the formation of porous layer is attributed to the dynamic impact pressure and hardenability of materials. It is also found that the impact-induced fusion during deposition of Zn coating can also modify the interfacial microstructure between particles in cold spray coating. Moreover, the nanocrystalline phase can be formed at the interfaces among particles resulting from the localized melting of the interfaces and tamping effect. Furthermore, the annealing treatment can modify the microstructure and property of a cold-sprayed coating.     

铜冶炼渣尾矿综合利用现状及研究

铜冶炼炉渣含有大量的有价金属元素,经过选矿工艺处理后,大部分铜被回收,选出的渣精矿返回熔炼炉,渣尾矿外售至水泥厂,尾矿中有价金属仍存在较大利用价值,在现有工艺流程后增加磁选工艺,磁选后的铁精粉用作炼钢配料,尾矿外售。主要介绍了熔炼渣及尾矿成分,现有工艺尾矿处理方式,新工艺的应用及实践。     

贵冶场面水预处理实验研究

为了降低废水处理成本,减轻废水处理压力,贵冶对部分污染物含量低的废水进行分类治理,硫酸生产场面水是其中之一。场面水预处理后达标,可送外排水系统处理或回用为生产用水。本研究采用硫酸铝溶液和 DTCR 溶液处理场面水,分别考察了反应溶液 pH、净化剂添加量对净化效果的影响。确定硫酸铝溶液净化反应的最佳条件为 ：反应体系的 pH 为 8,硫酸铝添加量为 2mL/L ;DTCR 溶液净化反应的最佳条件为 ：反应体系 pH 为 9,DTCR 添加量 2mL/L。在最佳工艺条件下进行的验证实验结果表明 ：经硫酸铝溶液和 DTCR 溶液分别处理后的场面水重金属含量达国标 GB 25467—2010 要求。相比现有废水处理工艺,具有流程短、药剂少、成本低和效果佳等特点。     

水质稳定剂HPDP缓蚀阻垢性能评定

用静态阻垢，旋转挂片失得法实验研究了ＨＰＤＰ对ＣａＣＯ３，Ｃａ３（ＰＯ４）２等的阻垢性能以及对Ｑ２３５碳钢的缓蚀性能等。试验证明，ＨＰＤＰ是一种优良的阻垢缓蚀剂，适用于高温，高碱，高ＰＨ，高浓缩倍数的循环冷却水处理，具有广阔的应用前景。