玻璃、环氧酚醛烘干漆衬里管道防蜡机理

对抽油机井产油、输油装置进行了模拟实验,同时进行了不锈钢、碳钢、玻璃、环氧酚醛烘干漆表面亲水特性实验和玻璃管、环氧酚醛烘干漆衬里管防蜡实验,研究了玻璃衬里管、环氧酚醛烘干漆衬里管的防蜡机理。与碳钢管相比,玻璃衬里管道内壁较强的亲水特性和光滑的表面是降低积蜡、防止管道堵塞之关键。在玻璃管壁与油流之间形成稳定的水膜,将原油与管壁隔开,阻止、减弱了原油和蜡在管壁上的沉积。环氧酚醛烘干漆衬里管道虽然具有较光滑的内壁表面,但由于具有较弱的亲水特性,防蜡效果比玻璃衬里管差。     

ns脉冲激光作用下K9玻璃的等离子体谱图研究

建立一套激光等离子体光谱测量实验装置,以Nd：YAG调Q倍频固体激光器为激发光源,作用K9玻璃。通过对K9的等离子体谱图的分析发现,K9玻璃等离子体谱强度的变化与激光器输出能量呈线性关系。同时利用显微镜观察K9玻璃的表面损伤形貌,并进行理论分析。     

Formation and biocorrosion behavior of Zr-Al-Co-Nb bulk metallic glasses

Ni-and Cu-free Zr-Al-Co-Nb glassy alloys with different Nb and Co contents were synthesized by melt spinning and copper mold casting.The effects of Nb addition to partially replace Co in the Zr55Al20Co25 glassy alloy on the glass-forming ability,thermal properties,in-vitro biocorrosion behavior and surface wettability of the metallic glasses were investigated.Although addition of Nb up to 5 at.% slightly decreased the supercooled liquid region and the glass-forming ability(GFA),the alloys could be casted in a bulk glassy rod form with diameters up to 3mm.The Zr-Al-Co-Nb glassy alloys were spontaneously passivated with low passive current densities in phosphate buffered saline and Hanks’ solution.Substitution of "toxic" Co by Nb is effective in improved the corrosion resistance of the Zr-Al-Co glassy alloy.Water contact angle measurements showed that Nb addition increased the hydrophilicity of the glassy alloys,which may enhance cell adhesion of the alloys in biomedical applications.     

氧对Zr50Cu40Al10块体金属玻璃晶化动力学的影响

利用不同锆原材料、采用电弧炉坩埚倾斜铸造法制备了具有不同氧含量的Zr50Cu40Al10三元锆基块体金属玻璃,研究了氧对合金热稳定性及晶化动力学的影响.研究结果表明:合金的热稳定性随其氧含量的增加而降低,但晶化表观激活能却随氧含量的增加而增加;氧是通过提高晶化反应速率常数而降低合金热稳定性的,热稳定性与反应速率常数之间存在良好的对应关系,反应速率常数可以较好地表征具有强烈动力学效应的块体金属玻璃晶化过程;氧提高合金晶化反应速率常数的原因是由于它增大了反应的频率因子.     

Super-plasticity of Zr<Subscript>64.80</Subscript>Cu<Subscript>14.85</Subscript>Ni<Subscript>10.35</Subscript>Al<Subscript>10</Subscript> bulk metallic glass at room temperature

Generally, bulk metallic glasses （BMGs） exhibit a very limited plastic deformation under a compression load at room temperature, often less than 2% before fracturing. In this letter, through an appropriate choice of BMGs＇ composition, an amorphous rod of Zr64.80Cu14.85Ni10.35Al10 with a diameter of 2 mm was prepared by using copper mold suction casting. X-ray diffraction and differential scanning calorimetry were utilized to determine its structure and thermal stability, and the uniaxial compression test was adopted to study its plastic deformation behavior at room temperature simultaneously. The results showed that the glass transition temperature and onset temperature of the exothermic reaction of the amorphous rod were 646 and 750 K, respectively, and its micro-hardness was 594.7 Hv. During compression, when the engineering strain and engineering stress arrived at 9.05% and 1732 MPa, respectively, i.e., the true strain and true stress reached 9.42% and 1560 MPa, respectively, the amorphous rod started to yield. After yielding, with the increase of load, the strain increased and the glass rod ulti- mately were compressed into flake-like form. Although the maximum engineering strain was larger than 70%, i.e., the maximum true strain exceeded by 120%, the amorphous specimen was not fractured, indicating that it has super-plasticity at room temperature. Through the appropriate choice of composition and optimization of the technological process, flexible BMG with super-plasticity at room temperature could be produced.     

掺Nd~(3+)硼硅酸盐玻璃的非线性光学特性

在调Q 纳秒Nd: YAG强激光脉冲下,使用闭孔Z-扫描技术研究了硼硅酸盐基质玻璃及其掺Nd3+玻璃的三阶光学非线性特性.发现基质玻璃具有正的三阶非线性折射系数和非线性吸收系数,属于自聚焦反饱和吸收型的光学介质;而随着Nd3+的掺入,该硼硅酸盐玻璃的三阶非线性折射和吸收系数较基质玻璃有明显的增大,远高于一个量级.用开孔Z-扫描实验与光限幅实验进一步验证了掺Nd3+玻璃具有较高的三阶非线性吸收系数,表明Nd3+的掺入提高了硼硅酸盐玻璃在532 nm处的激光防护性能.     

基于内聚力模型的夹层玻璃梁冲击破坏过程仿真

为了模拟夹层玻璃梁的冲击破坏过程,基于有限元中常用的内聚力模型的基本概念,提出了适用于三维球形离散单元的破坏模型.该模型将离散单元之间的作用分为连接型、内聚型和接触型3类.当两离散单元间满足破坏准则时,它们之间的作用由连接型变为内聚型,内聚力由离散单元之间的分开量求出.将该破坏模型在自主开发的离散元/有限元耦合计算程序CDFP中实现,并仿真了夹层玻璃梁的冲击破坏过程,得到了与试验结果相近的破坏形式,说明了该破坏模型和仿真分析方法的有效性.     

Zr_(55)Al_(10)Ni_5Cu_(30)大块金属玻璃的晶化行为研究

分别在603 K、653 K、683 K、723 K、753 K、793 K和0.5 h、1 h、2 h、3 h、5 h的保温时间下对Zr55Al10Ni5Cu30大块金属玻璃进行了退火热处理.采用x射线衍射(XRD)法分析了退火后Zr55Al10Ni5Cu30大块金属玻璃的弛豫和晶化相析出的过程,计算了不同温度下结晶度和纳米晶粒尺寸的大小.通过差示扫描量热(DSC)法分析了Zr55Al10Ni5Cu30大块金属玻璃的热稳定性.Kjssinger曲线分析表明,Zr55Al10Ni5Cu30大块金属玻璃弛豫后晶化激活能高于其淬态的晶化激活能,退火温度对大块金属玻璃热稳定性有显著影响.     

环境气压干燥新工艺快速合成SiO2气凝胶研究

以廉价的水玻璃为硅源,用乙醇（EtOH）／三甲基氯硅烷（TMCS）／庚烷混合溶液浸泡水凝胺,使对水凝胶的溶剂交换和表面改性在一步完成,在环境干燥条件下合成了SiO2气凝肢．所合成的SiO2气凝肢为轻质透明的块状固体,密度为0．128～0．165g／cm^3,孔隙率92．4％～94．2％．利用FT—IR、SEM、TEM和BET吸附对气凝肢的微观结构和形貌进行了研究,结果表明,气凝胶为纳米介孔结构,粒子直径和孔径分布均匀,断面呈现明显的蜂窝状结构,孔径13nm左右,比表面积约618m^2／g,表面带有较多的Si—CH3基团．     

Cu60Zr29Ti11大块非晶合金的黏度特征和强液体行为

*采用铜模铸造法制备了Cu₆₀Zr₂₉Ti₁₁大块非晶合金, 用X射线衍射仪、三点压弯式黏度仪对该非晶合金的动力学性质进行了研究. 测定了大块非晶合金Cu₆₀Zr₂₉Ti₁₁在过冷液相区的黏度, 得到了它的动力学脆性系数m=31, 以及流变激活能E=63.4 kJ/mol. 表明大块非晶合金Cu₆₀Zr₂₉Ti₁₁是一种强液体, 有较强的非晶形成能力, 形成非晶比较稳定. 分析了合金在过冷态的流变激活能变化规律, 发现流变激活能的变化并不符合Kivelson的Super-Arrhenius公式.