关键钢铁材料的智慧研发路线

从面向2035的新材料强国战略出发,针对现代交通、能源、海洋工程以及重大装备等领域,对其急需的关键钢铁材料在品种、规格、性能、质量、服役安全与寿命等方面均提出了明确的发展目标、应攻克的技术瓶颈和"卡脖子"问题.为适应未来先进钢铁材料的发展,应在钢铁材料知识与理论框架下,充分发挥集成计算材料工程及材料信息学的优势,创建新材料的智慧研发路线,实现中国先进钢铁材料的研发从跟随模仿跨越到基于人工智能创新引领的新高地.     

A new method to improve the stability,tensile strength,and heat resistant properties of shape‐memory epoxy resins: Two‐stages curing

In this article, we design a new thermal curing method: two‐stage curing. The purpose of using this approach is to maintain the excellent shape‐memory property of epoxy resin system after first stage curing, and the material can be folded in small size to storage or transportation and recovery its original shape commodiously by heating temperature. Then, after second stage curing, the stability, glass transition temperature(T_g), and tensile strength of material can be improved effectively. For this aim, a series of mixtures have been prepared. Differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), tensile test, scanning electron microscope (SEM), dynamic mechanical analysis (DMA), and fold‐deploy shape‐memory test have been used to characterize the feasibility of two‐stage curing process, curing degree, tensile strength, morphology, thermodynamic properties, and shape‐memory performance of these polymers. DSC results show that two independent curing stages can be achieved successfully. Tensile tests and DMA results suggest that tensile strength and heat resistance have been improved after the second curing stage. SEM results reveal that the addition of latent curing agent do not change the fracture mechanism. Furthermore, the fold‐deploy shape‐memory tests prove that the composites after first stage curing possess eximious shape‐memory property. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39882.     

Toughening‐modified epoxy‐amine system: Cure kinetics,mechanical behavior,and shape memory performances

Shape memory epoxy resins are derived on reacting E51 with triethylenetetramine in presence of the toughening agent polypropylene glycol diglycidyl ether (PPGDGE). The curing behaviors are studied with differential scanning calorimetry. The toughening system shows a decrease in activation energy. ?esták–Berggren model is utilized to establish the kinetic equations. The fitting results prove that the equations can well describe the reactions. Tensile tests and dynamic mechanical analysis are used to analyze mechanical performances and thermodynamics. Shape memory properties are characterized by fold‐deploy tests. The elongation at break increases as the concentration of PPGDGE increases. The toughening materials have lower glass transition temperature (T_g). The fixable ratios of all systems are greater than 99.5%. The shape recovery time decreases with increasing the PPGDGE concentration. The optimal system can fully recover its original shape in about 2 min at T_g + 30°C, and exhibit the maximum fold‐deploy cycles as 13 cycles. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40853.     

The crystallization morphology evolution of polyoxymethylene/poly(ethylene oxide) blend micropart prepared under microinjection molding conditions

This article is the first study on the microinjection molding and the effects of the microprocessing parameters on the crystallization and orientation of polyoxymethylene/poly(ethylene oxide) (POM/PEO) blend, which has better toughness and self‐lubricity compared with the neat POM and therefore is a better candidate material for making microparts like microgears with higher performances. The crystalline and phase morphologies were investigated by polarized light microscope (PLM), differential scanning calorimeter (DSC) and scanning electron microscope (SEM). The crystalline orientation of the microparts was evaluated by two‐dimensional wide‐angle X‐ray diffraction (2D‐WAXD) and Herman's orientation function. The experimental results showed that both POM and POM/PEO microparts prepared by microinjection molding exhibited three distinct layers, i.e., skin layer, shear layer and core layer, while the latter had thicker shear layer but thinner skin layer and core layer. PEO was well dispersed in POM matrix. The spherulite size, the melting point as well as the crystallinity of POM in the POM/PEO blend decreased due to the interference of PEO in the crystallization of POM. A shish‐kebab structure was observed in the shear layers of the POM/PEO microparts. The effects of processing parameters on the thicknesses of different layers of the POM/PEO microparts were investigated. With increase of the injection speed or decrease of the mold temperature, the skin layer and the core layer became thicker, while the shear layer and the oriented region became thinner. However, the influence of the injection pressure was not obvious. Also, the processing parameters affected the crystalline orientation of the POM/PEO microparts. With increase of the injection speed or decrease of the mold temperature, the orientation function f decreased, indicating a lower degree of orientation. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40538.     

Curing characteristics,morphology, thermal stability,mechanical properties,and irradiation resistance of methylethylsilicone/methylphenylsilicone rubber blends

Methylethylsilicone rubber (MESR)/methylphenylsilicone rubber (MPSR) blends were cured with 2,5‐dimethyl‐2,5‐di(tert‐butylperoxy)hexane. The curing characteristics, morphology, thermal behaviors, mechanical properties at different temperatures, radiation resistance, and thermal aging resistance of the MESR/MPSR blends were investigated. The results show that a high MPSR content could decrease the optimum curing time and improve the scorch safety. Dynamic mechanical analysis revealed that the glass‐transition temperature of the blends increased slightly with the addition of MPSR. Scanning electron microscopy showed that MESR and MPSR had good compatibility in the blends. Thermogravimetric analysis indicated that the thermal stability of the blends increased with increasing quantity of MPSR. The blends had excellent mechanical properties at low temperatures. However, these properties were significantly reduced when the temperature was increased. Moreover, changes in the mechanical properties decreased with increasing MPSR content at high temperatures, especially at temperatures higher than 100°C. In addition, the radiation resistance and thermal aging resistance of the blends increased with increasing MPSR content. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40529.     

Synthesis and characterization of Ca–Sr–P coating on pure magnesium for biomedical application

There are growing evidences that Sr-containing calcium phosphate biomaterials can promote better osteo-precursor cell attachment and proliferation than pure calcium phosphate biomaterials. In this study, attempts were made to fabricate two kinds of Sr-substituted calcium phosphate (Ca–Sr–P) coatings on pure magnesium in electrolyte solutions with differing amounts of Sr(NO₃)₂ for biomedical application. The surface microstructure, composition and chemistry of the coatings were characterized by Scanning Electron Microscope (SEM), Energy-dispersive X-ray Spectroscopy (EDS), and X-ray Diffractometer (XRD), respectively. In addition, electrochemical and immersion tests were performed to evaluate the corrosion resistance of the Ca–Sr–P coated magnesium in phosphate buffered saline solution (PBS).     

树脂吸附法对焦化废水的深度处理

介绍了焦化废水生化后尾水的深度处理工程实例。针对生化尾水的特点,选择了斜管沉淀、浅层介质过滤和树脂吸附的组合处理工艺,处理后尾水的色度、总氰化物、悬浮物的去除率分别达到89.7%、88.1%和69.6%,排水指标优于《炼焦化学工业污染物排放标准》(GB 16171—2012)中的要求,具有较好的应用前景。     

关于剂油比的技术分析

文章阐述了剂油比在催化裂化中的重要地位,分析了剂油比对反应过程的影响以及提高剂油比的手段,并通过上述方面对实际操作过程中如何合理调节这一重要参数提出指导性意见,以求达到平稳、合理的控制催化裂化的目的。     

航空煤油实际胶质测量不确定度的评估

根据《测量不确定度评定与表示》[1]测量要求,对航空煤油实际胶质测量不确定度进行合理评估,找到了影响测定结果准确性的主要因素,得出该方法的扩展不确定度u=0.4 mg/100 mL。     

开关电源用有机硅粘接固定胶的分类与选用探讨

文章主要介绍了室温固化(RTV)有机硅产品的分类及开关电源行业常用有机硅粘接固定密封胶的种类和选用时的优劣探讨。