EH40高强度船板Z向拉伸性能分析

利用扫描电镜及能谱仪对EH40的断口形貌、夹杂进行分析,结果表明：硫化物对钢板厚度方向抗层状撕裂性能的影响较大。为满足钢材Z向性能的要求,冶炼过程中应尽量控制硫的含量。     

改善40Mn2钢低倍质量的实践

介绍了40Mn2钢的特性及用途。结合石钢3#连铸机设备的实际情况,分析了导致40Mn2铸坯低倍内裂的原因。通过优化电磁搅拌参数和振动参数,基本消除了40Mn2钢材低倍内裂的缺陷问题,为连铸设备出现变化时如何保证生产提供了思路。     

三种植物叶片类胡萝卜素含量的比较分析

以红继木、红苋和七彩扶桑的叶片为材料,采用丙酮-乙醇法提取,利用紫外-可见分光光度计对三种植物叶片中胡萝卜素、叶黄素和总类胡萝卜素的含量进行了测定。结果表明,胡萝卜素含量:红苋>红继木>七彩扶桑;叶黄素含量:七彩扶桑>红苋>红继木;总类胡萝卜素含量:红苋>红继木>七彩扶桑。     

Matter Timed

At best, the ageing of materials is regarded as lending a patina to historic buildings. In reality, however, materials often age disgracefully and unevenly, requiring a high level of maintenance and refurbishment. What if materials could be engineered and integrated into buildings not only to enhance but to heal? Martina Decker , Assistant Professor in the College of Architecture and Design at the New Jersey Institute of Technology (NJIT), looks at pioneering research that is being undertaken into performative, time-dependent materials.     

pH敏感型交联微球的制备

采用铈盐-羟基氧化还原引发体系,以对苯乙烯磺酸钠(SSS)和葡聚糖(Dex)为原料,通过自由基接枝聚合将聚对苯乙烯磺酸钠(PSSS)接枝到Dex上,得到接枝共聚物Dex-g-PSSS,再通过交联反应合成C(Dex-g-PSSS)微球。利用FTIR、光学显微镜、Zeta电位仪表征了试样的结构和形态,研究了反应条件对PSSS接枝度的影响,考察了C(Dex-g-PSSS)微球在模拟胃液和结肠液中的溶胀率。表征结果显示,C(Dex-g-PSSS)微球为交联微球,其Zeta电位为绝对值较大的负值。实验结果表明,在适宜的反应条件(硫酸铈铵浓度12 mmol/L、H+浓度0.08 mol/L、Dex 5 g、SSS 5 g、50℃,6 h)下,可得到接枝度为11.86 g(基于100 g Dex-g-PSSS)的PSSS。C(Dex-g-PSSS)微球有较明显的p H敏感性,它在模拟胃液中的溶胀率仅有134%,在模拟结肠液中的溶胀率可达到678%,是潜在的口服结肠定位给药系统基质材料。     

Si元素对Al-40Zn-xSi 钎料组织和性能的影响

研究了Si元素对Al-40Zn-xSi 钎料的钎焊性能,显微组织的影响以及不同Al-40Zn-xSi钎料对铝合金钎焊接头的显微组织和力学性能的影响。结果表明：当Al-40Zn-xSi中Si元素含量为4%时,钎料具有最好的润湿性能。显微组织分析表明：当Si元素含量超过4%后,钎料中开始出现块状初生硅;铝合金钎焊接头水冷后,Al-Si共晶组织和Zn-Al共析组织共存于焊缝中α-Al 的枝晶间区域。当钎料中Si元素的含量为4%时,焊后水冷的铝合金钎焊接头的抗剪强度达到最大值142.28 MPa。但是,当钎料中Si元素含量为5%以上时,焊缝中会形成较多的脆性共晶组织和初生硅颗粒,影响接头力学性能。     

回火温度对40CrMoVNbTi钢组织和性能的影响

采用780℃亚温淬火和不同温度回火,探究回火温度对40CrMoVNbTi钢组织和力学性能的影响。对淬火不同温度回火40CrMoVNbTi钢的力学性能变化及显微组织和冲击断口断貌进行观察和分析。结果表明,780℃亚温淬火,随回火温度的提高,40CrMoVNbTi钢的强度下降,塑性呈上升趋势,300℃回火冲击吸收能量值最低,出现回火脆性。200℃回火组织为回火马氏体和残留奥氏体,其抗拉强度为2150 MPa,KV₂为23.8 J;550～600℃回火组织为回火索氏体,韧性较好,其抗拉强度为1190～1070 MPa,KV₂为94～123 J,满足AISI 4140钢的力学性能要求,具有较高的冲击性能。     

Role of activated carbon on micropollutans degradation by ionizing radiation

The objective of this study was to analyze the influence of the presence of activated carbon on the degradation of the triiodinated contrast medium diatrizoate (DTZ) by the simultaneous use of gamma radiation and activated carbon. Four commercial activated carbons (Ceca, Witco, Sorbo, and Merck) with different textural and chemical characteristics were used for this purpose. The percentage DTZ removal obtained was considerably higher with the gamma radiation/activated carbon (GM/AC) system than with radiolysis in the absence of activated carbon, and it depended on the specific activated carbon employed. First, we optimized the amount of activated carbon required to maximize the amount of DTZ removed by the GM/AC system (0.06 g). The degradation constants were higher with the GM/AC system than with radiolysis alone, evidencing a synergic effect that favors pollutant removal. This synergic effect is independent of the textural but not the chemical characteristics of the activated carbon, observing a higher synergic activity for carbons with a higher surface content of oxygen, specifically quinone groups. We also highlight that the synergic effect of the activated carbon requires adsorbent–adsorbate electrostatic interaction and is absent when this interaction is hindered.     

钢基耐磨SiC薄膜制备研究

用磁控溅射的方法在40Cr钢的表面制得了SiC薄膜.通过X射线衍射、傅里叶红外光谱分析、摩擦磨损以及划痕试验研究了工艺参数、溅射方式对薄膜性能的影响.结果表明:室温下,用磁控溅射法制备的SiC薄膜具有非晶态结构;傅立叶红外光谱证实了薄膜中除了Si-C键的存在外还有大量的Si-Si键;在相同的工艺参数下用射频溅射法制备的薄膜表面更为光滑致密,与基体结合更好;采用射频溅射法,在功率200W,时间为2h,工作气压为0.1Pa条件下制备的SiC薄膜性能最佳.     

微结构葡聚糖凝胶浓缩分离蛋白质的性能

采用UV,HPLC等测试方法研究了含微结构的葡聚糖凝胶（BHMs）对蛋白的浓缩分离性能。结果表明：含微结构的葡聚糖凝胶在室温下对牛血清蛋白的浓缩分离效率达95.3%以上,随温度的升高,浓缩分离效率降低,且当温度超过BHMs凝胶的低临界溶液温度(40℃)后,浓缩分离效率发生突变;和普通交联葡聚糖凝胶相比,通过控制流动相的温度,葡聚糖BHMs凝胶可实现对多种不同分子量蛋白的高效分离,提高了分离效率,分离时间由24h缩短至9h。吸水溶胀动力学以及SEM分析表明,BHMs凝胶的溶胀满足指数动力学方程,疏松多孔性结构及由其决定的温度敏感性是BHMs凝胶具备良好浓缩分离性能的原因。