鞍钢B级钢帘线盘条轧制工艺研究

根据钢帘线盘条对脱碳、氧化铁皮、金相组织、力学性能和表面质量的要求,制定了鞍钢B级钢帘线盘条轧制工艺,通过提高加热钢坯温度的控制精度,优化吐丝温度、吐丝圈径、辊道速度及佳灵装置开口度,减少在轧制、集卷、打包、装卸、堆放和运输等环节的表面划伤,生产出符合技术标准要求的B级钢帘线盘条,满足了用户需求。     

Facile preparation of low swelling,high strength,self-healing and pH-responsive hydrogels based on the triple-network structure

A polyacrylic acid(PAA)/gelatin(Gela)/polyvinyl alcohol(PVA)hydrogel was prepared by copolymerization,cooling,and freezing/thawing methods.This triplenetwork(TN)structure hydrogel displayed superior mechanical properties,low swelling ratio and self-healing properties,The superior mechanical properties are attributed to the triple helix association of Gela and PVA crystallites by reversible hydrogen bonding.The characterization results indicated that the fracture stress and the strain were 808 kPa and 370% respectively,while the compression strength could reach 4443 kPa and the compressive modulus was up to 39 MPa under the deformation of 90%.The hydrogen bonding in PVA contributed to maintain and improve the self-healing ability of hydrogels.Every type of hydrogels exhibited a higher swelling ratio under alkaline conditions,and the swelling ratios of PAA,PAA/PVA and PAA/Gela hydrogels were 27.71,12.30 and 9.09,respectively.The PAA/Gela/PVA TN hydrogel showed the lowest swelling ratio(6.57)among these hydrogels.These results indicate that the novel TN hydrogels possess good environmental adaptability and have potential applications in the biomedical engineering and sensor field.     

卧螺离心机内盐析流场的CFD-PBM耦合计算

目前对卧螺离心机内部流场的数值模拟大多采用传统欧拉模型,考虑其内部伴有盐析等固相粒子微观行为过程的研究少有报道。本文应用计算流体力学软件Fluent,基于群体平衡模型与多相流Eulerian模型、RNG k-ε模型耦合方法,对卧螺离心机内部盐析两相流场进行三维数值模拟,通过仿真与实验相结合的方式,得到卧螺离心机内盐析流场的晶体颗粒粒径分布、组分数分布和浓度分布及其变化规律,初步揭示了卧螺离心机内伴有盐析的流场晶体颗粒分布特性。研究结果表明：卧螺离心机内盐析晶体粒径的分布随液环半径的增大而增大,螺旋叶片正壁面粒径明显较背面大,从排液端至排渣端的晶体粒径分布有整体逐渐变大的轴向粒径梯度;流道内晶体粒径随转鼓转速的增大而减小,随进口固相体积分数的增大而增大;大粒径晶体的组分数在液环外侧及螺旋叶片正面附近相对较大,而中、小粒径晶体组分数的分布规律则与之相反;盐析颗粒浓度在液环外侧较高且分布均匀,且随转鼓转速的提高而提高,PBM模型与Euler模型计算结果有一定的相似与差异。     

速生杨枝桠材P—RC APMP浆的酶促磨浆

研究了纤维素酶和木聚糖酶对速生杨枝桠材P—RCAPMP酶促磨浆性能的影响。实验结果表明酶预处理可以改善P—RCAPMP浆的磨浆性能和成浆质量。纤维素酶和木聚糖酶预处理纸浆打浆度提高3-11°SR,磨浆能耗明显降低。最佳酶用量为25IU／g。与未经过酶预处理速生杨枝桠材P—RCAPMP浆相比,纤维素酶预处理纸浆裂断长提高12％,撕裂指数提高13％,耐破指数提高14％,耐折度提高50％,白度提高1．2％ISO。木聚糖酶预处理纸浆裂断长略有提高,撕裂指数提高15％,耐破指数提高12％,耐折度提高75％,白度提高1．9％ISO。酶预处理可抑制纸浆返黄。纤维素酶的酶促磨浆效果好于木聚糖酶。     

A Combined Ordered Macro‐Mesoporous Architecture Design and Surface Engineering Strategy for High‐Performance Sulfur Immobilizer in Lithium–Sulfur Batteries

The practical application of lithium–sulfur (Li–S) batteries is hindered by the “shuttle” of lithium polysulfides (LiPS) and sluggish Li–S kinetics issues. Herein, a synergistic strategy combining mesoporous architecture design and defect engineering is proposed to synthesize multifunctional defective 3D ordered mesoporous cobalt sulfide (3DOM N‐Co₉S_8?x) to address the shuttling and sluggish reaction kinetics of polysulfide in Li–S batteries. The unique 3DOM design provides abundant voids for sulfur storage and enlarged active interfaces that reduce electron/ion diffusion pathways. Meanwhile, X‐ray absorption spectroscopy shows that the surface defect engineering tunes the CoS₄ tetrahedra to CoS₆ octahedra on Co₉S₈, endowing abundance of S vacancies on the Co₉S₈ octahedral sites. The ever‐increasing S vacancies over the course of electrochemical process further promotes the chemical trapping of LiPS and its conversion kinetics, rendering fast and durable Li–S chemistry. Benefiting from these features, the as‐developed 3DOM N‐Co₉S_8?x/S cathode delivers high areal capacity, superb rate capability, and excellent cyclic stability with ultralow capacity fading rate under raised sulfur loading and low electrolyte content. This design strategy promotes the development of practically viable Li–S batteries and sheds lights on the material engineering in related energy storage application.     

一种典型的镗车头

本文介绍了一种新型的用于气门座圈密封带加工的镗车头,就其结构及工作过程做了较详细的阐述。     

原子吸收分光光度法连续测定锰粉中微量Fe、Pb、Sb、Ca和Cd

提出了原子吸收分光光度法测定锰粉中微量杂质（Fe，Pb，Sb，Ca，Cd）的方法。用硝酸溶解锰粉试样，在几个相同量的试液中，分别加入浓度依次递增的Fe，Pb，Sb，Ca和Cd等5种金属元素的标准溶液，再加入释放剂SrCl2溶液，用空气-乙炔火焰原子吸收分光光度法连续测定5种元素的含量。优化了仪器的测定条件，进行了相关的干扰实验。方法的回收率为97．6％～102．0％，相对标准偏差为1．8％～2．6％。     

Conductive MXene Nanocomposite Organohydrogel for Flexible,Healable, Low‐Temperature Tolerant Strain Sensors

Conductive hydrogels are attracting tremendous interest in the field of flexible and wearable soft strain sensors because of their great potential in electronic skins, and personalized healthcare monitoring. However, conventional conductive hydrogels using pure water as the dispersion medium will inevitably freeze at subzero temperatures, resulting in the diminishment of their conductivity and mechanical properties; meanwhile, even at room temperature, such hydrogels suffer from the inevitable loss of water due to evaporation, which leads to a poor shelf‐life. Herein, an antifreezing, self‐healing, and conductive MXene nanocomposite organohydrogel (MNOH) is developed by immersing MXene nanocomposite hydrogel (MNH) in ethylene glycol (EG) solution to replace a portion of the water molecules. The MNH is prepared from the incorporation of the conductive MXene nanosheet networks into hydrogel polymer networks. The as‐prepared MNOH exhibits an outstanding antifreezing property (?40 °C), long‐lasting moisture retention (8 d), excellent self‐healing capability, and superior mechanical properties. Furthermore, this MNOH can be assembled as a wearable strain sensor to detect human biologic activities with a relatively broad strain range (up to 350% strain) and a high gauge factor of 44.85 under extremely low temperatures. This work paves the way for potential applications in electronic skins, human?machine interactions, and personalized healthcare monitoring.     

Hierarchically Porous Multimetal‐Based Carbon Nanorod Hybrid as an Efficient Oxygen Catalyst for Rechargeable Zinc–Air Batteries

The lack of efficient strategies to address the intrinsic activity, site accessibility, and structural stability issues of metal‐carbon hybrid catalysts is restricting their real‐world implementation on the basis of rechargeable zinc–air batteries. Herein, a dual metal–organic frameworks (MOFs) pyrolysis strategy is developed to regulate the intrinsic activity and porous structure of the derived catalysts, where a Fe₂Ni_MIL‐88@ZnCo_zeolitic imidazolate framework (ZIF), with a hierarchically porous structure, multifunctional components, and an integrated architecture, acts as an ideal precursor to obtain multimetal based porous nanorod (FeNiCo@NC‐P). Benefitting from the synergetic effect of the multimetal components, facilitated reactant accessibility, and the well‐retained integrated structure, the resultant FeNiCo@NC‐P catalyst exhibits an oxygen reduction reaction half‐wave potential of 0.84 V as well as an oxygen evolution reaction potential of 1.54 V at 10 mA cm^–2. Furthermore, the practical application of FeNiCo@NC‐P in the zinc–air battery displays a low voltage gap and long‐term durability (over 130 h at a current density of 10 mA cm^–2), which outperforms the commercial noble metal benchmarks. This work not only affords a competitive bifunctional oxygen electrocatalyst for zinc–air batteries but also paves a new way to design and fabricate MOF‐derived materials with tunable catalytic properties.