超亲水及水下超疏油铜网的制备及其油水分离性能的研究

目的通过简单的溶液浸泡法制备油水分离铜网。方法经氢氧化钠和过硫酸钾混合溶液浸泡,制备超亲水及水下超疏油表面。利用扫描电镜、X射线衍射仪分析基底表面形貌及成分,利用接触角测量仪测量其润湿性能。结果铜网表面生成了微米结构的氢氧化铜,空气中水滴在其表面的接触角为0°,水中油滴的接触角高达159°,使铜网具备了在空气中超亲水、在水下超疏油的特性。通过油水分离实验发现,铜网在常温常压下对汽油、正己烷等几种不同种类油与水的混合液进行高效分离,分离效率达90%以上。经海水浸泡若干天后,铜网仍保持很高的油水分离效率,表现出较好的耐海水腐蚀性。结论实验制备的超亲水及水下超疏油铜网能够有效地分离油水混合液,且能应用到腐蚀性较强的场合中。     

纤维素/陶瓷复合膜的制备及油水分离性能研究

目的提高陶瓷膜对水包油乳化液的分离能力。方法将纤维素粉末充分溶解在氢氧化钠、尿素、水配制的溶解液中,低温真空下在多孔陶瓷分离膜表面构筑亲水性纤维素涂层。通过X射线衍射仪(XRD)、场发射扫描电子显微镜(SEM)、接触角测量仪、紫外-可见分光光度计表征纤维素/陶瓷复合膜的组成、结构、表面润湿性及水包油(甲苯)乳液分离效率。结果纤维素成功复合到多孔陶瓷膜孔隙表面,空气中水滴在膜表面的接触角为0°,水中油滴的接触角高达155°左右,使多孔陶瓷膜具备了在空气中超亲水-水下超疏油的特性。通过油水分离实验发现,在常温常压下,多孔陶瓷膜对水包甲苯乳液高效分离,其油水分离能力(99.26%)、抗污染性(经20次循环分离后,三种复合的平板陶瓷膜的水通量变化不大)得到显著提高,表现出较好的油水分离性能。结论陶瓷分离膜经纤维素修饰后,表面亲水性和水下超疏油性都得到了提高,油水分离能力可达99.26%,重复使用20次的纯水通量无明显衰减。     

基于梳齿沟槽阵列的集油表面润滑特性

对限量供油条件下梳齿沟槽阵列表面的润滑特性及其集油性能进行了研究。 利用飞秒激光在摩擦表面制备了梳齿状沟槽阵列,形成了条状亲油区。 采用摩擦力及膜厚测量仪的往复运动模块对该条状自亲油区在限量供油条件下的润滑成膜特性和减摩降磨特性进行了研究。 同时,采用高速摄像机对梳齿沟槽阵列表面油滴的输运特性进行了观察。 结果表明,以梳齿状沟槽阵列为边界的润滑轨道对置于其上的润滑油有明显约束作用,限制其向润滑轨道之外的铺展。 在有限供油条件下,该类条状自集油表面具有较好的润滑能力、较小的摩擦因数和磨损。 相对于普通润滑表面, 集油表面摩擦因数减小了 30%左右,而往复运动行程中心位置最小膜厚增大了 20 nm。 油滴在梳齿沟槽阵列表面的输运产生明显差异,朝向润滑轨道的输运距离为远离润滑轨道输运距离的 1. 5 倍。     

基于荧光水凝胶的功能表面器件

基于水凝胶体系的功能材料及应用发展迅速,在包括组织工程、能源存储、柔性器件等领域展现出广阔的应用前景。采用聚乙烯醇、壳聚糖和琼脂糖构建水凝胶主体结构,并添加羟乙基纤维素增塑保湿,添加碳量子点赋予材料荧光效应。制备获得了兼具有优良的自修复性能和优异拉伸性能的多网络结构水凝胶,具有高达33 MPa的拉伸强度并能够在多种媒介环境下实现快速的自修复,在空气中60 s自修复效率达93%。研究发现复合水凝胶材料的荧光强度同表面所受压强呈负相关性,而同其拉伸伸长率呈正相关。数据拟合证实,通过检测水凝胶的荧光强度可以监控其变形率,而结合水凝胶和仿壁虎表面结构制备出能够黏附于多种表面的压强检测器,通过对器件荧光强度的检测能够探测液下环境压强。该研究拓展了荧光水凝胶材料的应用途径,有望用于液下压强探测、工程结构失效监控等。     

超浸润不锈钢纤维毡制备及其乳化油/水分离性能

目的在不锈钢纤维毡表面进行超浸润性微纳结构的构建,减小纤维毡孔径并提升其耐污染性,实现乳化油的高效分离。方法先采用双阳极电化学沉积法,在不锈钢纤维丝表面沉积微米级铜颗粒,再采用双阴极电化学氧化法,将铜颗粒氧化为具有微纳结构的Cu(OH)_2纳米针。通过扫描电子显微镜、X射线衍射仪、接触角测量仪、油水分离测试、紫外可见分光光度计等手段,对样品的微观形貌、组成成分、润湿性和油水分离性能等进行了表征。结果经微纳米结构构建后,不锈钢纤维毡表面的浸润性由疏水(135°)变为超亲水(≈0°)/水下超疏油(161°),水包油乳液的分离效率可达99%,循环分离8次后,分离效率依然在99%以上,分离后滤液的透光率在98%以上,水包油中的油滴被有效去除。结论通过电沉积-电化学氧化法可在不锈钢毡纤维表面构建多孔微纳复合结构,该表面具有优异的超亲水/水下超疏油性能,可对水包油乳化油进行高效分离,且循环分离多次后未见明显衰减,显示出良好的耐污染性。     

基于图像处理技术界定微纳复合织构防覆冰性能

目的 制备具有防覆冰性能的微织构表面,准确评价微织构表面的结冰性能。方法 采用激光二次扫描方法,以铝合金为基底,构筑沟槽-凹坑型复合微织构表面,以水滴在其表面结冰过程的图像为对象,采用阈值法分割图像和背景,对提取出的图像进行形态学运算,通过分析水滴结冰过程中的轮廓变化规律,研究水滴结冰过程的状态变化,进一步界定水滴的结冰时间。结果 纳秒激光一次扫描形成的沟槽结构,增加了试件表面的粗糙度,使铝合金表面接触角由54.4°提高到116.5°,实现了铝合金表面的疏水性能。而二次扫描构建的沟槽-凹坑复合微织构,形成了Cw-Cn接触模型,进一步提高了试件表面的疏水性,试件表面接触角增大至154.4°。超疏水表面成核能垒高,且沟槽-凹坑复合微织构捕获的空气降低了固液界面的热交换速度,是铝合金表面结冰时间由11 s延长到551 s的原因。图像处理方法准确界定了水滴在结冰过程中的三个阶段。采用Harris角点检测法,可以实现精确判断结冰完成时间,减小了肉眼判断结冰状态所带来的主观误差。结论 纳秒激光二次扫描构筑的沟槽-凹坑复合微织构可以有效提高Al7075表面的疏水性,并延缓水滴在其表面的结冰时间。图像法处理提取的表面轮廓,为研究分析水滴在结冰过程中的状态变化提供了一种新思路。     

织构化表面处理抑制界面摩擦尖叫噪声

为寻求抑制摩擦尖叫噪声的新途径,对表面加工有不同尺寸及分布沟槽型织构的列车制动盘蠕墨铸铁试样进行摩擦噪声试验,探讨织构化表面处理对界面摩擦尖叫噪声特性的影响。结果表明:沟槽织构表面具有明显降低摩擦尖叫噪声的效果,系统在摩擦副接触界面为织构表面的半周期内无明显尖叫噪声产生,但在接触界面为光滑表面的半周期内会产生高强度尖叫噪声。说明沟槽织构表面降低尖叫噪声的主要机理为:沟槽棱边在摩擦过程中与对摩副碰击,抑制了系统自激振动及摩擦尖叫噪声的产生。     

超高频感应连续钎焊立方氮化硼磨粒的界面反应机理

采用超高频感应连续钎焊工艺,在不同扫描速度条件下实现了立方氮化硼(CBN)磨粒、Ag-Tu-Ti合金以及基体三者之间的钎焊连接。采用扫描电子显微镜(SEM)和X射线能谱仪(EDX)观察钎焊后的CBN磨粒界面新生化合物形貌。结果表明:随着扫描速度的变化,在CBN磨粒表面生成颗粒状TiN化合物以及针状和六棱柱状的TiB2化合物。其中,TiN尺寸为100 nm左右,而TiB2尺寸小于200 nm。在超高频感应连续钎焊CBN磨粒表面首先生成颗粒状TiN层,然后在TiN层外围形成柱状TiB2层,最终形成CBN/TiN/TiB2/钎料结构。当扫描速度为0.5 mm/s时,可以获得较好的界面新生化合物层结构。     

超声缓冲杆仿真研究

采用有限元方法对超声波在缓冲杆中的传播结果进行了仿真,找出尾随信号产生的原因,通过打乱圆柱/空气界面的方法,设计出多种形状的超声缓冲杆。实验发现,具有单锥形和双锥形结构的钢制缓冲杆能够很好的抑制尾随信号的出现,同时随着双锥形缓冲杆锥角在一定范围内不断增大,抑制效果愈加明显,可以达到较高的信噪比。     

表面沟槽与润滑剂协同作用对摩擦振动和噪声特性的影响

目的 提升表面沟槽的减振降噪性能,延长其寿命,通过试验方法探索合适的优化方式。方法 借助数控加工方法在蠕墨铸铁材料表面加工出一定尺寸沟槽,并在沟槽填充固体润滑剂MoS2,以获得具有不同时变特性的表面。采用球-平面接触方式进行摩擦对比试验,研究沟槽与固体润滑剂MoS2协同作用对界面摩擦振动及噪声特性的影响。结果 沟槽与MoS2固体润滑剂协同作用时,不仅有效地缓解了过沟冲击振动,还进一步抑制了摩擦振动及噪声的产生。与光滑表面相比,填充MoS2的表面噪声主频幅值降低约13.4 dB。结论 该试验条件下,接触表面粘着撕裂和犁削作用等产生的“不平顺”界面因素是激发摩擦振动及产生噪声的主要诱因。沟槽与MoS2结合不仅维持了界面的完整性,还能保持其时变特性,能减缓并削弱“不平顺”界面因素的产生,进一步优化表面沟槽减振降噪的功能,并能减小磨损,延长沟槽的使用寿命。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

THERMODYNAMICS STUDY ON THE DECOMPOSITION OF CHROMITE WITH KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

INFLUENCE OF HEAT TREATMENT ON DAMPING BEHAVIOUR OF THE MAGNESIUM WROUGHT ALLOY AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.     

An Easy Way to Quantify the Adhesion Energy of Nanostructured Cu/X(X=Cr,Ta,Mo,Nb,Zr) Multilayer Films Adherent to Polyimide Substrates

An approach based on film buckling under simple uniaxial tensile testing was utilized in this paper to quantitatively estimate the interfacial energy of the nanostructured multilayer films(NMFs) adherent to flexible substrates. The interfacial energies of polyimide-supported NMFs are determined to be *5.0 J/m2 for Cu/Cr, *4.1 J/m2 for Cu/Ta,*2.8 J/m2 for Cu/Mo, *1.1 J/m2 for Cu/Nb, and *1.2 J/m2 for Cu/Zr NMFs. Furthermore, a linear relationship between the adhesion energy and the interfacial shear strength is clearly demonstrated for the Cu-based NMFs, which is highly indicative of the applicability and reliability of the modified models.     

High-Speed Friction Stir Welding of SiC_p/Al–Mg–Si–Cu Composite

A 17 vol% SiCp/Al–Mg–Si–Cu composite plate with a thickness of 3 mm was successfully friction stir welded(FSWed) at a very high welding speed of 2000 mm/min for the first time. Microstructural observation indicated that the coarsening of the precipitates was greatly inhibited in the heat-affected zone of the FSW joint at high welding speed, due to the significantly reduced peak temperature and duration at high temperature. Therefore, prominent enhancement of the hardness was achieved at the lowest hardness zone of the FSW joint at this high welding speed, which was similar to that of the nugget zone. Furthermore, the ultimate tensile strength of the joint was as high as 369 MPa, which was much higher than that obtained at low welding speed of 100 mm/min(298 MPa). This study provides an effective method to weld aluminum matrix composite with superior quality and high welding efficiency.     

A STUDY OF TEMPERATURE-DEPENDENT VALENCE BOND STRUCTURE OF TITANIUM

On the basis of energy and shape method for the determination of the valence bond (VB) structures of crystal, the valence bond structure of titanium is redetermined at room temperature and calculated in the whole temperature range of 0-1943K. The outer shell electronic distribution of Ti is e_c~(2.9907) · (s_c~(0.4980) d_c~(2.4927)) ef1.0093 in crystal. The temperature dependences of the VB structures of hcp and bcc phases are the same. The VB structures of hcp and bcc phases monotonically increase or decrease with the increase in temperature, but show discontinuous changes at the phase-transformation temperature 1155K.     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。