基于静电传感技术的液压泵状态监测技术研究

对液压泵的常见故障及常用监测方法进行了分析,提出将静电传感器技术运用到液压系统在线监测中。研究了液压泵油液在线监测机制、磨粒荷电量的影响因素,设计了一套适用于液压系统的油液在线监测系统,研究了磨粒浓度、大小及材质与传感器测量电压之间的关系。运用静电传感器在线监测液压系统工作介质中磨损颗粒的荷电情况,得到液压泵磨损的监测结果,验证了静电监测方法在液压泵在线监测中的有效性与可行性。     

气流粉碎/静电分散中粉体颗粒运动规律的数值模拟研究

通过经典力学及流体力学基本原理,建立轨道模型对气流粉碎/静电分散相复合制备超微粉体中粉碎分散仓内颗粒的运动过程进行了数值模拟研究,揭示了气流粉碎/静电分散过程中粉体颗粒的运动规律。当荷电电压为20 k V,射流速度较低时粉体颗粒流存在准稳态层流流动现象;随着射流速度的提高,粉体颗粒转变为弥散分布,且分散性具有一定程度的提高;当荷电电压增大至60 k V时,仓内粉体颗粒的分散性有了进一步的提高,呈现出较好的均匀分散状态。研究结果表明,增大射流速度和荷电电压能够有效的提高制备过程中粉体颗粒的分散性,且后者效果更为明显。     

静电喷涂荧光渗透检测线的建造及应用

对于大型的复杂型面零件，静电喷涂荧光渗透检验具有独特的优势。介绍了静电喷涂荧光渗透检测线的建造思路和布局，总结了在建造过程中的经验教训。结合静电喷涂荧光渗透检验操作工艺，说明了在实践中的应用情况，提出了静电喷涂荧光渗透检验适合在民航维修中推广应用。     

油罐内壁导静电涂料的导静电性能研究

根据石油储罐导静电要求，笔者在研制阻燃导静电耐温防腐蚀涂料过程中，对影响油罐内壁导静电涂料的导静电性能的因素进行了试验研究，本文就其主要因素－成膜物质种类，导静电材料类型，微粒形态结构，用量，湿度，固化时间以及其它添加剂的作用等方面进行探讨。     

纳米TiN在水中的分散行为研究

通过测定沉降体积和粘度,研究了纳米TiN在水中的分散行为和表面活性剂聚乙烯亚氨(PEI)对分散的影响,用Zeta电位测定了颗粒表面的荷电变化,提出了分散机理.结果表明:pH值对纳米TiN在水中的分散性有很大的影响,等电点在pH=5.2左右;碱性环境下的分散性显著优于酸性环境,在pH=10左右,获得良好的分散效果,对应的Zeta电位绝对值最高,表明纳米TiN在水中的分散行为遵循静电稳定机制.研究也发现,PEI对纳米TiN在水中的分散行为有重要影响,PEI能够进一步改善料浆的分散性,合适的添加量为0.0614%(质量分数,下同).PEI不仅改变了颗粒表面的荷电性质,而且增大了Zeta电位的绝对值.PEI改善分散性的原因归结于静电空间位阻效应.     

油罐内壁导静电涂料的导静电性研究

根据石油储罐导静电要求，笔者在研制阻燃导静电耐温防腐蚀涂料过程中，对影响油罐内壁导静电涂料的导静电性能的因素进行了试验研究。本文就其主要因素──成膜物质种类、导静电材料类型、微粒形态结构、用量、湿度、固化时间以及其它添加剂的作用等方面进行探讨。     

铝材表面处理的几种方法

简要介绍电泳涂漆、静电涂漆和粉末静电喷涂的原理、工艺及设备情况，并对其性能进行了比较。     

石油储罐导静电涂料使用情况的调研报告

为了进一步提高石油储罐的防腐蚀效果，加强储罐导静电涂料的使用管理，完善其操作规范，同时为制定导静电涂料国家标准提供科学依据，石油罐导静电涂料国家标准起草工作组和中油新技术开发公司等组成调研组，对中石油所属部分油库的石油储罐使用导静电涂料情况、法规执行情况、防腐材料的应用、技术指标、施工程序、验收标准和应用效果逐一进行了调研。石油罐导静电涂料监测规范国家标准管理组宋广成高级工程师在本文中介绍了调研情况。     

涂料雾化状况对静电喷涂效果的影响

通过对涂料雾化状况的评价,阐述和讨论了涂料雾化状况对静电喷涂效果的影响,对静电喷涂过程出现的一些问题从理论上作出解释,阐明了雾化效果在静电喷涂过程中的重要性。     

静电涂油机中油液荷电雾化实验研究及雾化机理探讨

以静电涂油机中油液的衙电雾化实验研究为基础，从静电学原理角度出发，对静电涂油机的雾化机理进行了探讨，得出了适合该情况的理论计算公式。通过雾化实验与雾化机理探讨，为新一代静电涂油机的研制开发的参数选择提供了理论依据。     

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.     

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。     

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.     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

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).     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.     

Directional Growth of Tin Crystals Controlled by Combined Solute Concentration Gradient Field and Static Magnetic Field

A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.