液压蓄能式公共汽车制动能量回收系统匹配与试验分析

针对城市公共汽车运行的特殊工况,设计并研制了一种新型液压蓄能式制动能量回收系统,介绍了该制动能量回收系统的组成和工作原理,对液压系统主要部件参数进行了分析与匹配。通过台架和实车道路试验,结果表明:所设计的液压蓄能式制动能量回收系统在满足汽车运行安全的前提下,具有较高的制动能量回收率,对改善汽车的燃油经济性具有积极作用。     

平衡式变量叶片泵节能研究

针对实际汽车液压转向系统中转向油泵的输出流量高于实际需求的流量的现象,提出了一种含有浮动块的新型平衡式变量叶片泵,该泵具有速度补偿特性,能降低泵的无功功率消耗.同时建立了汽车液压助力转向系统的数学模型和汽车液压动力转向系统的Matlab Simulink仿真模型,对平衡式变量叶片泵选择不同的参数进行输出功率特性仿真,对输出结果进行对比和分析.仿真结果表明,该泵在不同转速条件下的功率输出平稳,可显著减少汽车尾气排放和噪声,节能效果明显.是一种较有应用前景的新型转向叶片泵.     

变刚度碟形弹簧减振器在冲床上的应用

分析了冲床减振器刚度对冲床设备基础及机身振动的影响,介绍了一种具有硬-软-硬变刚度特性的碟形弹簧减振器的开发与应用,该减振器有4个减振柱,采用C型碟簧,弹簧组合采用多组对合且各组叠合片数逐渐增加,与同类减振器相比,该减振器能量吸收率高,振动缓冲效果好,既能有效降低冲床设备基础的振动,也能限制机身振动幅度的增大,该减振器成本低廉且使用方便可靠。     

汽车助力转向系统流量分析

介绍了汽车助力转向器的结构和工作原理,分析了汽车助力转向系统的流量特性和助力转向泵的恒流特性,阐述了造成汽车助力泵能量损失的原因。给出了助力转向系统工作流量和助力泵输出流量之间的匹配关系,为进一步研究开发高效低能耗的助力泵产品提供了理论基础。     

基于压电效应的新型蓄能器设计

阐述压电效应以及普通气囊式蓄能器吸收压力脉动的原理。针对液压系统需要减少压力脉动的需求以及压电材料能将外界振动能量直接转变为可利用的电能的特点,设计一种压电式气囊蓄能器,相对于普通气囊式蓄能器,不仅能够更好地衰减液压系统中的压力脉动,还能将一定的振动能有效回收。     

一种新型汽车磁流变液减振器的设计

根据磁流变减振器的工作原理提出了一种JETTA轿车新型汽车磁流变减振器的机械结构,利用FEM方法优化了磁流变减振器的磁路设计和机械结构设计,并通过减振效果实验进一步验证了磁流变减振器的磁路设计和机械结构设计的正确性。该减振器机械结构简单,减振实时控制,具有较好的减振效果。     

数控冲床振动分析及缓冲系统研究

通过理论推导和振动测试,分析冲床缓冲系统的减振器刚度大小和刚度特性对设备基础及机身振动的影响,提出综合考虑基础振动的减小和机身振幅增大的减振器刚度确定方法;介绍一种具有硬-软-硬变刚度特性的碟形弹簧减振器的开发,一个减振器有4个减振柱,采用C型碟形弹簧,弹簧组合采用多组对合且各组叠合片数逐渐增加。与同类减振器相比,该减振器能量吸收率高,振动缓冲效果好。     

基于 MATLAB的振动压路机橡胶减振器的参数优化分析

在振动压路机压实工作中,强烈的振动有损于机器零件的使用寿命和操作员的身体舒适度,因此振动“适度”成为压路机设计的一个关键问题.振动压路机减振器设计的重要参数是减振器的刚度和阻尼,直接决定减振效果.介绍振动压路机的运动学模型,阐述减振系统减振性能的影响因素及评价方法,建立基于MATLAB的振动压路机橡胶减振器参数计算模型,在达到一定减振效果的条件下,实现了压实效果最优的减振系统的设计,为压路机设计中橡胶减振器的参数选择提供了一定的理论依据.     

带有减振底座的双向液压振动试验系统研制

为解决液压振动试验系统需要建设减振地基所带来的建设周期长、占地面积大、成本高等问题,提出并研制了带有减振功能底座的双向液压振动试验系统。介绍该液压振动试验系统的结构组成和工作原理,并详细阐述减振底座、伺服作动器及翻转装置等核心部件结构组成;依据技术指标要求和JJG 638-2015液压式振动试验系统国家计量检定规程,对液压振动试验系统进行0.5～200 Hz/4g正弦扫频测试,对系统的台面加速度波形失真度、台面加速度均匀度和台面横向振动比等核心性能指标进行了测试。测试结果表明:液压振动试验系统的台面加速度波形失真度、台面加速度均匀度和台面横向振动比等核心性能指标均满足JJG 638-2015液压式振动试验系统国家计量检定规程要求。     

基于SimulationX电控液压助力转向系统的仿真分析

设计一种新型的电控液压自动助力转向系统(EHPS),将车速和转向盘转矩引入到系统中,实现了转矩、车速感应型助力特性的液压助力转向,既可保证转向轻便、实时,提供足够助力,又能减少能量损失,有利于环保.基于Sim-ulaitionX软件建立了EHPS系统仿真模型,分析结果表明:系统具有良好的控制精度和快速响应特性.并通过改变PID控制器参数进行仿真,获得电机最理想的转速.     

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.     

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.