冷却速度对C-Si-Mn系热轧双相钢组织性能的影响

通过实际的热轧实验,研究了轧后冷却速度对C-Si-Mn系热轧双相钢组织形貌和力学性能的影响。研究发现,轧后冷却速度对热轧双相钢的显微组织和力学性能有很大的影响。热轧双相钢具有三种典型的组织形貌,而不同的组织形貌通过不同的强化机制赋予热轧双相钢不同的力学性能。通过不同冷却速度下的双相钢热轧实验,可以使热轧双相钢获得良好的力学性能。     

A new high strength and high tolerance-resistance A1-Li alloy

In order to develop a new high strength and high tolerance-resistance Al-Li alloy which can be used in aerospace industry, the effects ofmicroalloying elements such as Mg, Ag, Mn and Zn on the mechanical properties of Al-Cu-Li alloys were studied. The results show that the strengthening effects of Mg＋Ag and Mg＋Zn additions are higher than those of the individual Mg, Ag or Zn addition. The element Mn can also bring some extent strengthening effects on the alloys, but it has nothing to do with the other microalloying elements present or not. Finally, a new Al-Li alloy with Mg＋Zn＋Mn additions was developed, which possesses high strength and high tolerance-resistance promising properties for aerospace applications.     

防锈铝表面喷丸强化冲击试验研究

采用仪器化（数字化）冲击试验机，对防锈铝表面喷丸强化后进行冲击试验，试验结果表明：喷丸后的最大冲击力比母材提高35％，最大力前弹塑性变形功提高166％。     

铜-不锈钢复合材料在HSO3-和/或Cl-介质中的腐蚀行为

采用选择腐蚀技术，提取了铜一不锈钢复合材料中的纤维相，并测定了纤维相电极电位。通过循环加速腐蚀试验和电化学测试方法，研究了3种铜一不锈钢复合材料和纯铜在HSO^3-和／或Cl^-介质中的腐蚀行为。同时研究了腐蚀对材料的力学性能、导电性能和显微组织的影响。结果表明，Cu-10wt％SS原位(微观)复合材料在HSO3^-和／或Cl-介质中具有一定的耐蚀性。HSO3^-对铜-不锈钢复合材料腐蚀的影响显著。     

Microstructure development of steel during severe plastic deformation

The microstructure development during plastic deformation was reviewed for iron and steel which were subjected to cold rolling or mechanical milling (MM) treatment, and the change in strengthening mechanism caused by the severe plastic deformation (SPD) was also discussed in terms of ultra grain refinement behavior. The microstructure of cold-rolled iron is characterized by a typical dislocation cell structure, where the strength can be explained by dislocation strengthening. It was confirmed that the increase in dislocation density by cold working is limited at 10¹⁶m⁻², which means the maximum hardness obtained by dislocation strengthening is HV3.7 GPa. However, the iron is abnormally work-hardened over the maximum dislocation strengthening by SPD of MM because of the ultra grain refinement caused by the SPD. In addition, impurity of carbon plays an important role in such grain refinement: the carbon addition leads to the formation of nano-crystallized structure in iron.     

ANALYSIS ON THE BEHAVIOR OF PRECIPITATES IN ULTRA-THIN HOT STRIP OF PLAIN LOW CARBON STEEL PRODUCED BY COMPACT STRIP PRODUCTION

This paper investigated the mechanism of precipitation and its influence upon prop-erties of ultra-thin hot strips of low carbon steel produced by CSP techniques using experiment and thermodynamics theory. The experimental results show that there are lots of fine and dispersive precipitates in microstructures. By analysis, most of aluminum nitrides are in grains, while coexisted precipitates of MnS are along grain boundaries. Coexisted precipitates compose cation-vacancy type oxides such as Al2O3 in the core, while MnS is at the fringe of surface. The precipitation behavior of AlN and MnS in the hot strip is studied by thermodynamic calculation. At last, implica-tions between strengthening effect and techniques are analyzed using obtained solubility products.     

7CrSiMnMoV钢的马氏体形态及其强韧性研究SCIEI

本文用金相及电子显微分析研究了7CrSiMnMoV钢的马氏体形态及亚结构,并对不同形态的马氏体转化规律进行了分析。研究发现该钢冷却产生的马氏体有三种类型,包括晶界上优先产生的具有位错亚结构的宽大板条马氏体,晶内较细小的板条马氏体以及内部少量的孪晶马氏体片。基于上述结果,本工作试用短时等温淬火形成的下贝氏体来代替晶界马氏体,证明晶界组织形态对材料的强韧性有着很大的影响。     

Poly(pentahydropyrimidine)-Based Hybrid Hydrogel with Synergistic Antibacterial and Pro-Angiogenic Ability for the Therapy of Diabetic Foot Ulcers

Bacterial infection and impaired angiogenesis make the treatment of diabetic foot ulcers (DFU) extremely challenging. Cationic polymers are expected to treat infected wounds due to their excellent antibacterial properties, but still, it is difficult to meet the therapeutic needs of pro-angiogenesis and anti-infections due to their simple construction units and outmoded synthesis methods. Herein, a cationic poly(pentahydropyrimidine) (PPHP) library with strong modifiability is synthesized to construct a hybrid hydrogel with synergistic therapeutic effects for the treatment of infected DFUs. It is found that the as-synthesized hybrid hydrogel can up-regulate angiogenesis-related gene (HIF-1, VEGF, and bFGFR/bFGF) expression and targeted disruption of bacterial cell membranes, which finally promotes the healing of infected DFU (wound healing rate: 92%) within 10 days. This hydrogel, thus, holds great promise in developing new strategies to significantly enhance the treatment of DFU and other bacterial-infected pathological diagnoses.     

Fe3Se8/Co3Se4/NiSe2/NC复合材料的制备及性能

由于锂资源的价格逐渐攀升,亟需开发价格低廉的电池系统。通过共沉淀法合成FeCoNiCP片状前驱体,再经过包覆多巴胺、退火和在氮气下硒化,制备钠离子电池负极材料Fe₃Se₈/Co₃Se₄/NiSe₂/NC。在0.01~3.00 V充放电,以0.1 A/g的电流循环70次,电极仍有468.38 mAh/g的可逆比容量;在0.1 A/g、0.2 A/g、0.5 A/g、1.0 A/g、2.0 A/g和5.0 A/g的电流下,分别具有363.85 mAh/g、345.88 mAh/g、320.73 mAh/g、308.31 mAh/g、290.33 mAh/g和249.29 mAh/g的可逆比容量。Fe₃Se₈/Co₃Se₄/NiSe₂/NC复合材料较好的电化学性能,可归因于碳导电网络、多金属硒化物和独特的纳米结构的协同作用,缓解了充放电过程中的体积膨胀。     

面向联合检修的电力信息物理系统输电线路脆弱相关性辨识

为减少用户停电时间,电力企业常采取“一停多用,联合检修”模式。然而,检修计划往往侧重于关注线路本身的运行状态,而缺乏对电网整体运行性能的考虑。在跨区联合检修中,由于多条线路陆续停电检修,系统的脆弱性可能被放大。电力信息物理系统之间的融合关系也可能加剧故障跨域传播的深度和广度。在协同破坏效应下,系统存在连锁故障及大停电的可能。为此,提出一种该场景下输电线路脆弱相关性的辨识方法。首先,对联合检修中的能量流动和信息传输过程建模,构建联合检修事故记录数据库。其次,挖掘数据库中存在脆弱相关性的线路组合,通过计算线路组合在诱发停电事故时的贡献度,实现脆弱相关性的量化。仿真结果表明：联合检修时,脆弱相关的线路组在物理层和信息层都表现出了协同破坏效应。所提方法能有效地辨识和量化线路组的脆弱相关性,为制定更加合理的联合检修计划、避免大停电事故的发生提供理论指导。