纳米C60晶体表面化学镀镍工艺研究

为了改善纳米C60晶体的在液体中的分散性能,并保持其自身的特异性能,采用化学镀的方法实现了纳米C60晶体表面金属化。研究了其镀覆工艺和配方,观察了镀镍层显微形貌,检测了其物质元素组成,并测定了其在液体中的Zeta电位。研究结果表明,表面金属化大大改善了其在液体中的分散性能,可提高其参与化学复合镀的能力。     

管路效应对液压冲击器性能影响的研究

在液压冲击器的研究中,往往忽略了高压胶管在冲击器中的作用,对其理论研究也较少。国内外对管道的研究主要集中在钢管方面,而对系统影响较大的液压胶管的研究较少。本文运用管道集中参数模型的方法详细研究了高压胶管的数学模型,并应用Matlab／Simulink对其进行仿真,其结果可为液压冲击器的进一步研究提供一定的理论依据。     

氩弧焊活性焊剂配方研究现状

介绍了氩弧焊活性焊剂的研究现状,从非金属氧化物、金属氧化物和卤化物角度阐述了其在不同钢种中的应用,认为活性焊剂配方的研究和其增加熔深机理研究是活性焊接技术的核心.     

纯水卸荷溢流阀的实验研究

介绍了自行研制的纯水卸荷溢流阀的结构特点及工作原理,并对其进行了实验研究,测试了其静动态性能,分析了影响纯水卸荷溢流阀动态特性的因素。试验研究结果表明该阀在额定压力下,其静动态性能可满足使用要求。     

高压输电线路巡检机器人机械结构研究现状及发展趋势

随着国家电网的发展,高压输电线路的人工巡检任务日趋繁重,因此利用智能机器人技术代替传统的巡检方法已经是国内外研究的热点。结合目前国内外巡检机器人的研究现状,对其机械结构研究现状进行了分析,并归纳了其类型以及行走机构、越障机构的结构特征,提出了电力巡检机器人的发展趋势。     

型交叉杆并联机床运动学分析

研究了一种特殊构型6 UPS并联机床的运动学。根据机床实物建立虚拟样机模型,并用李群李代数理论对其位姿变换进行描述;采用旋量理论对该机床的自由度进行了分析;在运动学反解的基础上,求解了其工作空间形状,描述了其可加工几何范围;在运动学模型的基础上,采用四元素法和广义逆对其位置正解进行了研究,得到唯一正解;通过虚拟样机仿真,分析了该机床的位置正反解过程、速度雅克比矩阵、电机驱动函数以及几何约束条件等,为进一步研究其运动性能和运动控制提供了参考。     

具有不同壁厚的金属型近共晶Al-Si合金铸件的自退火效应(英文)

为了揭示冷却速度对铝硅合金中β相的大小及分布的影响,研究其凝固过程中的自退火效应,设计了一套实验装置并进行实验。对铝硅合金试样的不同壁厚部位中的β相特征进行研究。研究发现,其颗粒的尺寸分布符合对数正态分布。为了研究不同壁厚处以及不同冷却条件下的性能,还进行了布氏硬度实验。实验表明,试样在水中冷却时其硬度比在空气中冷却时更均匀,并且其平均硬度更高。     

石油储罐用水性导静电防腐涂料的研究

文章介绍了对石油储罐用水性导静电防腐涂料的研究情况,并重点讨论分析了影响其防腐性、导静电性的主要因素,并对其制备的水性导静电防腐涂料的性能进行了测试研究。     

微塑性成形的基础研究

随着科学技术的不断发展,产品的微型化趋势明显加强.由于微塑性成形有其独特的优点,近年来,国内外专家和学者对其展开了广泛而深入的研究.该文介绍了近年来微塑性成形技术的基础研究现状并进行了归纳.     

新型冷作模具钢SDC55的性能研究

对比研究了新型冷作模具钢SDC55和进口模具钢DC53、SLD及ASSAB88的抗弯曲性能和耐磨损性能。在电子万能试验机上对实验钢的抗弯曲性能进行了测试,并在M-200磨损仪上研究了其耐磨性能。利用超景深三维显微系统研究了实验钢磨损后的磨痕,并对其进行了金相观察。利用JMat-Pro软件对4种实验钢的组织进行了计算。通过对比研究发现,与进口对比钢相比,新型冷作模具钢SDC55的抗弯曲性能最好,并且其耐磨损性能好于SLD钢。     

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.     

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.     

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。