风淬工艺对粒化不锈钢氩氧脱碳炉渣的影响

为了改善不锈钢氩氧脱碳炉渣的稳定性,采用风淬法对不锈钢氩氧脱碳炉渣进行粒化试验,研究了炉渣碱度、改质剂、温度、风速和喷吹角度对其粒化效果的影响规律。结果表明,渣粒平均粒径随着碱度的降低先减小后逐渐增大,碱度为1.8时平均粒径达到最小值4.31 mm;添加氧化硼改质后,粒化渣平均粒径随着碱度的降低与改质前变化趋势相同,但整体减小;随着熔渣温度升高,粒化渣粒平均粒径增大;随着风速增大和喷吹角度减小,粒化渣粒平均粒径逐渐减小,在21.5 m/s风速下得到最小粒径3.67 mm,当喷吹角度为25°时达到最小粒径4.28 mm。     

上海中心大厦塔冠外露钢结构防腐涂装体系的研究与实践

上海中心大厦塔冠是国内房屋建筑史上第一次达到600 m以上高度的塔顶建筑,由于其结构复杂、关联设备众多、环境条件严酷、施工难度大,常规的钢结构防腐经验难以适用。通过对塔冠自然条件和施工条件的深入分析,陈述了原方案的否定、调整和再否定,并在大量工程调研的基础上,提出了新的长效防腐体系。通过试验检验,结合严格的工艺质量控制,使这一新的组合配套防腐体系在大厦塔冠钢结构防腐实践中得到落实应用。     

不同改性下再生混凝土抗压性能的试验研究

提出了再生混凝土改性方案,通过掺加粉煤灰、硅灰、钢纤维、聚丙烯纤维等矿物掺合料,提高再生混凝土抗压强度;进行了普通混凝土、再生混凝土、改性再生混凝土立方体抗压强度试验;分析了粉煤灰、硅灰、钢纤维、聚丙烯纤维等矿物掺合料对再生混凝土抗压强度的影响;给出了各类矿物掺合料对再生混凝土强度的影响规律。     

浅谈地下车库种植土顶板防水技术

地下车库种植屋面容易产生渗漏,为避免漏水点出现后影响建筑使用功能,分析造成种植屋面渗漏的成因,并通过工程实例,探讨新型防水材料PBC-328非固化橡胶沥青防水涂料的施工工艺流程及操作要点。     

聚丙烯改性技术及制品应用

介绍了我国聚丙烯质轻、耐腐蚀、易加工、力学均衡性好、价廉,但低温脆性大和成型收缩率大的特点、世界用量等发展现状及改性技术,列举一些改性技术实例,说明在复合材料中聚丙烯既可以作为增强材料也可以作为基体等情况。     

Expression of the transportation of corrosive media into epoxy coating using nano-indentation

Nano-hardness (H_nano) and nano-elastic modulus (E_nano) of corroded coating surface layer were investigated using nano-indentation after epoxy coated specimens were immersed in 5% NaCl solution. The penetration depths (d) of corrosive media into epoxy coating were calculated fitting the curves of (H/E)_nano vs. indentation depth (h). EIS spectra of epoxy coated specimens immersed in 5% NaCl solution for different time were measured. Finally the relationship of capacitance (C_f,T) of corroded epoxy coating with the penetration depth of corrosive media was studied. The experimental results showed that the transportation process of corrosive media into epoxy coating was studied through the profiles of (H/E)_nano with indentation depth. The penetration depth of corrosive media into the epoxy coating increases rapidly with immersed time firstly, and then increases slowly. The capacitance of corroded epoxy coating has a linear function relationship with the penetration depth of corrosive media into epoxy coating. Nano-indentation can be used to study the transportation process of corrosive media into organic coating.     

Surface hierarchical porosity in poly (ɛ-caprolactone) membranes with potential applications in tissue engineering prepared by foaming in supercritical carbon dioxide

This article describes the preparation of porous poly (ɛ-caprolactone), PCL, membranes by supercritical CO₂ (SCCO₂) foaming, displaying surface hierarchical macroporosity which could be tailored by careful control of the pressure, in the range of 150–250 bar, and depressurization processes in several steps, showing also pore interconnectivity between both membrane faces. The membranes exhibited two distinct types of surface macroporosity, the larger with diameter sizes of 300–500 μm were surrounded by and also composed of smaller pores of 15–50 μm (same size as inner pores). Membranes were prepared by solvent casting and submitted to different SCCO₂ foaming. Parameters such as membrane thickness, CO₂ flow, foaming time, pressure, temperature and the depressurization processes (rate and profiles), were varied to determine their influence on final porosity and to decipher which parameters were the most critical ones in terms of surface hierarchical pore organization. No remarkable changes in PCL crystallinity were found when membranes were processed under SCCO₂. Finally, biological evaluation of the porous membranes was achieved by seeding human skin fibroblasts on the prepared membranes. The results, in terms of cell adhesion, spreading, proliferation and metabolic activity indicate that these membranes could hold promise for the fabrication of meshes with controlled porosity for tissue engineering applications.     

一种高效过滤亚微米级细颗粒的新液固过滤技术——表层过滤

论述一种新的可高效过滤液体中亚微米级细颗粒的表层过滤技术,分析了表层过滤技术的特点、过滤模式、表层过滤基本条件和设计计算中所必需的数学模型。介绍了表层过滤技术在我国工业生产上推广应用的概况。     

工程机械表面涂层早期缺陷与防治措施

针对采用液体涂料进行涂装的各类工程机械,调查表面涂层常出现的早期缺陷,分析其产生的原因并提出了防治建议措施。     

一段转化炉竖琴管排吊簧改造及调整

针对一段蒸汽转化炉厚壁型炉管(HK-40)改薄壁型炉管(HP-Nb+M)后,因单根炉管重量减少近30%,受压恒力吊簧无调节功能,不能满足新载荷工况下的使用要求问题,于1996年和2007年两次对弹簧K(弹性系数)值进行校验。鉴于校验值与设计值无明显变化,弹簧特性还处于良好状态,从降低设备改造成本考虑,对竖琴管排承重吊簧进行改造使用,由新核定的工作载荷确定新工况下A、B吊簧改造后的冷态"O"值,并确定管排安装方法和吊簧的冷、热态调整要求。