氯盐体系锡隔膜电沉积仿真模拟

采用COMSOL多场耦合计算机仿真软件对氯盐体系锡隔膜电沉积进行了仿真模拟,研究锡隔膜电积时电解槽内离子浓度、流体密度、流体速度、电流密度等的分布特征及其随时间的变化规律。结果表明:锡隔膜电积时槽内离子浓度分布受到入口流速、电流密度、电积时间、槽内离子互相作用的影响而发生变化。增加进液速度及降低HCl浓度有利于提高电解液平均密度及阴极表面Sn^2+的最低浓度。电积时极板边缘发生离子对流,顶部对流速度高于边缘处对流速度,且流体密度梯度影响离子对流方式。极板周围电流密度分布呈非均匀分布,在电极边缘发生电流偏转。增加电流密度能降低阴极表面Sn^2+最低浓度及流体的平均密度,同时也将增加阴极表面流体的平均流速,并使得阴极产物厚度不均匀。     

高浓度Bi3+离子对Cu电解精炼中阴极过程的影响

采用线性电位扫描法、循环伏安法、电导测定及XRD,XPS法等研究了高浓度Bi3+离子存在于酸性CuSO4电解液中对Cu电解精炼阴极过程的影响.研究表明Bi3+离子的存在减小了电解液的电导率,降低了阴极Cu沉积反应的交换电流密度、极限电流密度和峰电流密度,对Cu沉积反应起极化作用.在通常电流密度200 A·m-2下电解,Bi不会在阴极沉积,但促使Cu沉积的晶面220择优取向更加突出.在高电流密度1000 A·m-2下电解,Bi以Bi2O3形式存在于沉积层中,Cu沉积的晶面择优取向为111.     

铜离子对工业电解液中镍电结晶行为的影响EI北大核心CSCD

研究铜离子浓度对工业电解液中镍电结晶过程的影响。采用传统三电极体系,通过阴极极化法、循环伏安法、计时电流法分析铜离子对镍电结晶初期行为的影响。利用电位阶跃和霍尔槽实验制备沉积层并通过SEM观察其微观组织形貌,通过XRD分析其择优生长取向。结果表明:不同质量浓度铜离子的加入使得镍电结晶过电位降低,镍的起始沉积电位发生正移,但并不改变镍形核/长大的生长方式。铜离子的加入使镍形核弛豫时间t_(m)逐渐缩短,峰电流I_(m)逐渐增大;当铜离子质量浓度为0.5和1.0 g/L、阶跃电位为−0.85 V时,镍电结晶处于三维连续形核和三维瞬时形核之间;当阶跃电位处于−0.90~−1.00 V时,接近于三维瞬时形核。随着铜离子浓度增大到1.5 g/L、2.0 g/L时,镍电结晶由三维连续形核转变为三维瞬时形核;镍−铜电解液在电沉积过程中更适用于三维瞬时形核/生长机制。随着铜离子的引入,镍和铜发生共沉积,沉积层晶粒尺寸变大;沉积层的形貌由最初的小圆球颗粒逐渐变为金字塔状,生长方式以螺旋位错生长方式为主,晶粒逐渐由(111)面转变为(111)、(220)面生长。     

Urea-NaCl-ZnCl2离子液体中电沉积Zn-Ti合金

采用电化学方法研究urea-NaCl-ZnCl2-TiCl4离子液体中Ti(Ⅳ)在玻碳电极的阴极还原过程,并应用恒电位沉积考察温度、电位和ZnCl2含量对沉积层的影响。结果表明:阴极反应为准可逆反应,Ti(Ⅳ)可逐步还原为Ti(0);在低碳钢上,Zn和Ti发生诱导共沉积,得到平整的沉积层;适当提高沉积温度和电位可使沉积颗粒细化,镀层表面更加致密平整,但ZnCl2含量的增加对Zn-Ti合金沉积有阻碍作用;当ZnCl2的摩尔分数为10%、温度为80℃、沉积电位为1.5~2.0 V时,得到的镀层平整、致密、光滑,粒径约为0.8μm。     

喷射电沉积镍阴极极化行为研究

通过阴极极化曲线的测定研究了硫酸盐电解液喷射速度u(流速)对电流密度jc和阴极过电位ηc的影响．结果表明。电流密度为140A／dm^2时，喷射速度由0．83m／s增大到5．00m／s，阴极过电位从1．48V增至8．52V．与槽镀搅拌作用相比，电解液流速增大。有利于氢还原析出，导致过电位显著增大．随电流密度增大，阴极上析氢步骤逐渐取代水合镍离子电化学还原步骤成为整个过程的控制步骤，过电位可达12．03V。     

冷轧带钢表面形貌测试及其粗糙度均匀性控制研究

为了改善带钢表面粗糙度不均匀所引起的表面性能不良,采用双机架平整机进行了湿平整工艺试验,研究了平整毛化辊表面形貌及其遗传规律对带钢表面形貌的影响;改变了对毛化辊及平整后带钢表面形貌的测试方法,以Rsk及不同C值的Rpc为测试指标来评价平整毛化辊及平整后带钢表面形貌。结果表明:通过调整平整毛化辊的表面形貌,可以改变带钢对平整辊形貌的复制遗传规律,从而改善平整后带钢的表面形貌,其效果较调整其他平整工艺参数更为直接有效。通过减少平整毛化辊表面3×R_a的Rpc,平整后带钢的Rsk趋近于0,提高了Rpc(C=0.25 μm)个数,平整后带钢表面的粗糙度更加均匀。因此,采用Rsk和不同C值的Rpc来评价平整毛化辊及平整后带钢的表面形貌,较采用粗糙度R_a值的评价方式,可以较好地评价粗糙度的均匀性。     

AlCl3-BMIC离子液体中Na+含量对铝电沉积的影响

测定AlCl3-BMIC离子液体(摩尔比2:1)电导率与Na+含量的关系,采用循环伏安法研究不同Na+含量离子液体的电化学性能,并通过恒电流电沉积考察Na+含量对槽电压、电流效率、沉积层形貌及电沉积铝纯度的影响。结果表明:随着Na+含量增加,离子液体的电导率和铝电还原峰值电流密度降低,交换电流密度增加,传递系数基本保持不变;而且铝沉积的电流效率降低、能耗增加。此外,当离子液体中Na+含量低于0.2 g/L时,对铝沉积层形貌影响不大,当Na+含量增加到0.5 g/L时,沉积层变得平整致密,颗粒减小,但进一步增加Na+含量,颗粒又逐渐长大。离子液体中Na+的存在对铝沉积层的纯度影响很小,即使Na+含量高达2.0 g/L,铝沉积层中Na含量也非常低。     

1,3-二甲基-2-咪唑啉酮-AlCl3-Cu2O离子液体电沉积金属铜

为找到一种电沉积金属铜的新方法,选用1,3-二甲基-2-咪唑啉酮(DMI)、AlCl₃和Cu₂O(摩尔比为90∶10∶4)的溶剂化离子混合液体进行铜的恒电位电沉积,并分析了电解质的离子结构、电导率、黏度和密度等。拉曼光谱和核磁共振分析表明DMI-AlCl₃-Cu₂O体系中存在[AlCl₂(DMI)₄]⁺、AlCl₃(DMI)₂和[AlCl₄]^-等离子团,DMI-AlCl₃-Cu₂O体系的电导率、黏度和密度随温度在323～373 K区间内呈线性变化。循环伏安研究表明,铜的起始还原电位为-0.4 V(vs Al),还原峰电位为-1.35 V;在-1.1 V至-1.4 V条件下恒电位电沉积得到金属铜,在-1.1 V和-1.4 V电位下电沉积得到的产物表面较平整,在-1.2 V和-1.3 V电位下电沉积得到的产物...     

从复合离子液体中电沉积制备铱（英文）

为研究复合离子液体中电沉积制备Ir的工艺过程,探讨添加剂N,N-二甲基乙酰胺(DMAC)对BMIC-BMIBF4复合离子液体黏度、电导率及电化学稳定性的影响,分析Ir Cl3在该复合体系中的电化学行为,并在不同电位下恒电位电沉积Ir层。采用扫描电镜及X射线衍射仪对沉积层形貌及组成进行表征。结果表明:DMAC的加入使复合体系的黏度降低、电导率升高、电化学稳定性提高;金电极上的循环伏安测试表明,Ir3+通过一步还原反应生成单质Ir的过程是受扩散速率控制的不可逆过程,其平均转移系数为0.170,扩散系数为1.096×10-6cm2/s;SEM显示,在还原峰电位处可以获得较为致密、平整的Ir层,而XRD谱表明Ir层为多晶结构。     

电沉积层厚度分布均匀性的研究进展

厚度分布尽可能均匀是绝大多数电沉积应用场合努力实现的目标。从电解液组分、电源、电沉积槽、阳极与阴极的结构形状及布局、电解液的搅拌方式等方面介绍了它们与电沉积层厚度分布之间的关系及其研究进展。协同改善电沉积过程中阴极的电场与流场分布是众多研究的主要思路,并在经验性改进方案和案例性数值仿真方面取得很大进展。未来的探索应更多地从理论角度提出通用性解决方案。     

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.     

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.     

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。     

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.     

Structural Optimization of Electromagnetic Swirling Flow in Nozzle of Slab Continuous Casting

During the slab continuous casting process, the flow field of molten steel in the mold plays a decisive role in the quality of the slab. In this paper, electromagnetic swirling flow in nozzle technology is proposed to control the flow field in mold.This technology can drive molten steel to rotate inside the submerged entry nozzle by electromagnetic force, thereby controlling the flow field. This research shows that it can reduce the impact of molten steel on the bottom of nozzle and partly reduce the negative pressure at the upper part of nozzle outlet which is even eliminated by optimizing the structure and angle of nozzle. The area of heat flux of the mold wall becomes larger, and the crest value of heat flux gets lower than that without swirling in nozzle and any nozzle optimization. The meniscus fluctuates smoothly, and the flow velocity at the top surface is within a reasonable range. The temperature field distribution in the mold is uniform which was beneficial to the growth of equiaxed crystal and decreased element segregation.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).