原料配比对银/卤化银参比电极性能的影响

使用热浸涂方法制备了不同AgCl/AgBr配比的银/卤化银(Ag/AgX)参比电极.通过SEM观察,不同含量的Ag/AgX电极表面形貌差别不大.XRD分析表明,各配比的AgX为角银矿晶型.电极的电位稳定性、耐极化性能以及内阻测试表明,原料配比对电极性能有影响.随着AgBr含量的减少Ag/AgX电极的内阻与极化电阻减小,在AgCl/AgBr为77/23时电极的电位稳定性与耐极化性能较好.Ag/AgX参比电极在海水中的电位漂移较小.     

热浸涂银/氯化银和银/卤化银参比电极对比研究

使用热浸涂-电化学还原法制备了银/氯化银(Ag/AgCl)和银/卤化银(Ag/AgX)参比电极.通过SEM观察发现电化学还原后的Ag/AgCl和Ag/AgX参比电极表面均有还原不均匀的现象.XRD分析表明,AgX晶体为AgCl和AgBr的固溶体,AgCl和AgX的晶型都为面心立方结构.电化学性能测试表明Ag/AgCl参比电极的极化电阻和温度系数比Ag/AgX参比电极小,Ag/AgCl电极电位稳定性略优于Ag/AgX电极.在Br~-含量不同的溶液中测试表明Ag/AgCl参比电极电位受Br~-变化影响比Ag/AgX参比电极小.     

还原方法对热浸涂银/卤化银参比电极的影响

分别使用热浸涂-氢还原与热浸涂-电化学还原方法制备了银/卤化银(Ag/AgX)参比电极。采用SEM观察、电化学阻抗测量、耐极化性能测试等方法研究了参比电极的微观结构和电化学性能,结果表明,不同还原方法对电极性能有明显影响。电化学还原法制备的电极较氢还原法所制备的电极内阻小,比表面积大,耐极化性能好。不同还原法所制备的电极的电位稳定性和温度系数没有明显区别。     

新型海洋用全固态Ag/AgX复合参比电极的性能

以聚苯胺(PANI)和聚吡咯(PPy)为电极添加剂，采用粉末压片法制备了Ag/AgX/PANI和Ag/AgX/PPy参比电极，在模拟海洋环境中进行了稳定性、温度响应特性、恒流极化和线性极化等性能测试。结果表明：Ag/AgX/PANI和Ag/AgX/PPy电极都具有与纯Ag/AgX电极同等优异的电位稳定性，且温度系数由0.36 mV/℃分别降低至0.27 mV/℃和0.26 mV/℃;在±5μA/cm²恒电流密度条件下，两种复合电极电位均在1 h内达到稳定，其中Ag/AgX/PPy电极的电位漂移值更小，这与线性极化结果相一致；Ag/AgX/PPy电极在静态和动态海洋环境中的电位波动值在0.30 mV左右，进一步表明了Ag/AgX/PPy电极是一种有潜力的新型海洋用全固态复合参比电极。     

全固态Ag/AgCl参比电极电位稳定性的影响因素

采用热浸涂-电化学还原工艺制备得到全固态Ag/AgCl参比电极,并研究了Cl-浓度、温度、光照、水流流速及pH值对电极的影响。结果表明,制备的全固态Ag/AgCl参比电极Nernst响应和温度响应特性较好,温度系数较小;当溶液中有溶解氧存在时,光照会使电极表面生成Ag2O,使电极电位发生漂移;随海水流动速度的升高,Ag/AgCl参比电极的电极电位呈下降趋势,而pH值的变化对电极电位基本没有影响。     

热浸涂银/氯化银参比电极性能研究

    使用热浸涂法制备了银/氯化银(Ag/AgCl)参比电极.通过SEM和EDX对电极表面的形貌和成分分析发现,在AgCl晶界的交界处易被优先还原.XRD分析表明,浸涂温度升高,Ag/AgCl电极的晶粒尺寸变小.电化学性能测试表明,热浸涂Ag/AgCl电极具有良好的电位稳定性;随着浸涂温度的升高,Ag/AgCl电极的极化电阻减小,双电层电容增大,比表面积增大,耐极化性能有所提高.     

银/氯化银参比电极漏电流情况下的失效机理

采用热浸涂-电化学还原方法制备了Ag/AgCl参比电极,通过加速极化试验方法研究了电极失效过程及机理。采用扫描电子显微镜(SEM)、能谱仪(EDX)和电化学阻抗(EIS)测试手段研究了电极失效过程中表面状态、形貌及性能的变化。结果表明,Ag/AgCl参比电极失效后电极电位出现大幅波动,电极表面呈疏松多孔结构,AgCl完全转化为银,Ag/AgCl参比电极在漏电流情况下失效的主要原因是电极中AgCl被还原为银所致。     

Ag/AgCl参比电极性能研究

电解法制备了Ag/AgCl参比电极,并用电子探针分析了其形貌及成分,跟踪了电极在3.5%NaCl溶液中的电位稳定性及长期极差变化,研究了电极对Cl-和温度的响应,并采用恒电流极化的方式测量了其抗极化性能.结果表明,所制备的Ag/AgCl参比电极在3.5%NaCl中稳定性、准确性良好,长期极差变化小,对Cl-响应性好,温度系数小,不易极化,可尝试作为高精度测量装置的敏感元件使用.     

压片法制备氯离子传感器的工作性能

采用压片法制备了以Ag/AgCl为工作电极,MnO2为参比电极的氯离子传感器。并且对传感器进行了长期稳定性试验、能斯特方程测试、温度试验、离子干扰试验和恒电流极化试验。结果表明,氯离子传感器稳定性良好,能斯特方程线性相关性强。温度对传感器工作性能影响不大,但是其他离子的存在对传感器电位值有一定影响。恒定流极化试验表明氯离子传感器抵抗极化能力较差。     

银/氯化银参比电极寿命评价

采用热浸涂-电化学还原方法制备了银/氯化银参比电极,通过极化容量方法预测了电极的寿命,采用扫描电子显微镜(SEM)、能谱仪(EDX)和电化学阻抗(EIS)测试手段研究电极极化容量测试前后表面状态、形貌及性能的变化。结果表明所研制的银/氯化银参比电极达到了20年寿命所需极化容量值。     

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).