超大型钢混凝土柱脚灌浆施工技术

随着社会的发展,超高层建筑越来越多,型钢混凝土结构能够极大的减少混凝土柱截面尺寸,因此普遍应用在超高层建筑中。本文阐述了钢柱柱脚与混凝土底板之间二次灌浆的施工工艺及操作要点,可确保型钢柱脚灌浆的密实性,保证工程施工质量。     

基于大气等离子喷涂的镍铬基粉末制备及其涂层组织结构

以高能球磨后的镍基合金、银、氟化物共晶复合粉末为原料,采用喷雾干燥和烧结技术制备了粒径为20～110μm的热喷涂喂料,利用等离子喷涂技术制备了镍基复合涂层。分析了喂料粒子物理性能及涂层的微观组织结构。结果表明:造粒后的粉末球形度较好,流动性大为提高。造粒烧结处理过程中,随着温度增加,粉末的流动性和松装密度均提高。经800℃热处理烧结后形貌圆整光滑,密实,平均粒径为32.92μm,松装密度为1.37g/cm~3,流动性为12.18s/50g,适合用作热喷涂喂料。制备的涂层为典型的层状结构,厚度约为320μm。涂层总体比较致密,局部存在孔洞,涂层孔隙率约3.6%。所含物相为NiCr、Ni_3Al、NiAl、Ag,BaF_2、CaF_2等相,喷涂过程中未见新物相生成。     

某铅锌尾矿粒度与其作水泥混合材性能的灰色关联

水泥混合材中尾矿的掺量和粒度分布对水泥性能有一定影响。为了提高掺加尾矿的水泥混合材的性能,以福建尤溪某铅锌尾矿为主要掺加料,以灰色关联分析为手段,研究了有无减水剂情况下铅锌尾矿粒度分布对水泥混合材胶砂流动度和胶砂试块抗压强度的影响。结果表明:提高尾矿细度有利于提高水泥胶砂的流动度和胶砂试块的抗压强度;在尾矿掺量为30%时,胶砂流动度与胶砂试块的抗压强度均与尾矿中+8.39μm粒级负相关,与-8.39μm粒级正相关,其中与8.39~4.24μm粒级关联度最大,与4.24~2.15、2.15~1.09及1.09~0μm粒级的关联度依次减小;要提高该铅锌尾矿水泥混合材的性能,在尾矿掺量为30%时,应尽量增加-8.39μm粒级的产率,尤其应增加8.39~4.24μm粒级的产率,并尽量降低+8.39μm粒级的产率。     

钢渣粉掺入对高强尾矿混凝土性能的影响

为了研究钢渣粉掺入对高强尾矿混凝土性能的影响,以比表面积为5 950 cm2/g的钢渣粉等量替代比表面积为5 137 cm2/g的基础胶凝材料(铁尾矿、矿渣、水泥熟料、天然石膏的梯级磨矿产品,各对应成分的质量比为40∶26∶26∶8)进行了胶砂流动度试验,并以等质量的原始粒级铁尾矿为骨料,进行了混凝土试件强度试验。结果表明:钢渣粉的掺入在一定程度上提高了体系的流动度;钢渣粉的掺入对混凝土早期强度有明显的负面影响;钢渣粉水化作用的缓慢、持久释放,使掺钢渣粉的混凝土后期强度显著增长,但钢渣粉的掺量不宜超过20%。试验产品的SEM分析表明,无论是否掺加钢渣粉,尾矿混凝土水化产物均为钙矾石和C-S-H凝胶;在反应的中后期,体系中C-S-H凝胶和钙矾石的协同生成能够促进体系强度的增长。     

钻井液处理剂对固井水泥浆的污染影响

深井固井中水泥浆和钻井液界面接触污染是一项危及施工安全的技术难题。为此,以川渝气田为例,有针对性地开展了固井中流体相容性的室内实验与分析。实验测定了目前常用的钻井液处理剂对常规密度水泥浆流动度、稠化时间的影响;利用红外光谱分析、电镜扫描、X射线衍射分析获得了聚丙烯酰胺钾盐(KPAM)和生物增黏剂的红外光谱数据,以及添加处理剂的水泥浆的红外光谱、电镜扫描、x射线衍射分析数据;同时还探讨了常用钻井液处理剂对固井水泥浆的污染机理。实验结果表明,KPAM和生物增黏剂等处理剂为高分子,其长链易吸附水泥浆中的水泥颗粒形成混合网状结构,造成水泥浆颗粒团聚增稠.进而失去可泵性。最后建议,进一步完善钻井液处理剂对固井水泥浆污染影响的评价实验方法,尽早形成一种能帮助解决固井水泥浆污染问题的规范标准,以便为固井前钻井液性能调整、钻井液处理剂合理选材、新的钻井液处理剂研发等提供技术参考。     

PPE黏度对MPPE性能的影响

采用双螺杆挤出,在相同工艺条件下制备了四种改性聚苯醚(MPPE)产品,研究了不同特性黏度的聚苯醚(PPE)对MPPE性能的影响.结果表明:随着PPE黏度的增加,MPPE的力学性能明显提高,耐热性能有较大改善;但熔体流动速度变慢,成型加工性能有所降低.     

Characteristics of alternate supply of shielding gases in aluminum GMA welding

Recently, unlike conventional method in supplying shielding gas, a newly method which alternately supplies different kinds of shielding gases in weld zone is developed and partly commercialized. However, literature related to the present status of the technology in the actual weld field is very scant. To give better understand on this technology, this study was performed. Compared with conventional gas supply method, the variations of weld porosity and weld shape in aluminum welding with alternate supply method of pure argon and pure helium were compared with conventional gas supply method with pure argon and argon + 67%helium mixture, respectively. As a result, compared with the welding by supplying pure argon and argon + 67%helium mixture by conventional method, the welding by supplying alternately pure argon and pure helium, produced lower degree of weld porosity and deeper and broader weld penetration profile.     

SAN/CPE/PC合金的制备与性能研究

利用氯化聚乙烯(CPE)弹性体、苯乙烯-丙烯腈(SAN)以及聚碳酸酯(PC)共混制备了高韧性的SAN/CPE/PC合金。研究了不同含量的PC对PC/SAN/CPE合金性能的影响。结果表明:随着PC用量的增加,合金的缺口冲击强度逐渐增加,拉伸强度逐渐降低。当SAN/PC的质量比为50/50,CPE质量分数为10%时,缺口冲击强度达到14 kJ/m2,接近于SAN/CPE二元体系CPE质量分数为40%时的缺口冲击强度。合金熔体质量流动速率随着PC含量的增加逐渐降低。     

Fluorometric analysis on physicochemical properties of phosphatidylcholine-based W/O microemulsion involved with enzymatic reactivity in phospholipid hydrolysis

Interfacial tension and fluorometric analysis were employed for the investigation of the interfacial local fluidity and the hydrophobicity of the micro water pool in the PC-based water-in-oil (W/O) microemulsion. These microenvironment properties strongly influenced the phospholipase A₂ reactivity for phospholipid hydrolysis in the W/O microemulsion. The organic phase was prepared by mixing of isooctane as a main solvent and 1-butanol as a co-solvent. The critical micelle concentration (CMC) was dramatically decayed from 9mM to 0.025mM by the increasing of the 1-butanol content. The local interfacial fluidity of the micro water pool was measured by using fluorescence polarity indicated by 1,6-Diphenyl-1,3,5-hexatriene-4′-trimethylammonium tosylate (TMA-DPH) and Coumarin 343 (C343). It was apparently increased with increasing the molar ratio of additive 1-butanol. In contrast, the hydrophobicity of the water pool measured by C343 was almost constant throughout the molar ratio of additive 1-butanol. Additive alcohol influenced the micro fluidity and enhanced reactivity of phospholipase A₂ in lipid hydrolysis. This work was presented at 13 ^th YABEC symposium held at Seoul, Korea, October 20–22, 2007.     

汽车用薄壁注塑高流动高刚性聚丙烯复合材料的制备及表面优化

该论文为汽车用薄壁注塑高流动性高刚性聚丙烯(PP)复合材料的制备及优化.通过在配方中组合采用高流动抗虎皮纹PP、包覆型滑石粉母粒(解决滑石粉与PP的相容性)、三元共聚PP(解决乙烯-辛烯共混物(POE)与PP的相容性)三种主要材料,以及K树脂、有机硅和其他助剂,再结合薄壁注塑模具在加强筋、卡扣部位的专门设计,结合了材料...