基于PLC的建筑砌块成型机液压系统设计

建筑砌块成型机是墙砖压制成型的关键设备。伴随着国内全自动液压机的研发成功及用户对产品质量和生产效率要求的提高,砌块成型机控制系统也在不断地更新。为了克服传统接触器、继电器控制方式接线复杂、工作不稳定、可靠性低的局限性,采用基于可编程控制器的智能控制系统对整机液压系统进行改进。研究结果为建筑砌块成型机液压系统的进一步优化提供依据。     

粉煤灰蒸压砖成型机液压系统设计与仿真研究

根据粉煤灰蒸压砖的工艺需求,蒸压砖成型机压制部分采用上下缸同时加压的方法;在重点分析下缸结构特点的基础上,给出双泵双回路的液压控制系统。基于AMESim软件,建立液压系统仿真模型,对下缸动态特性进行分析。结果表明:该系统能够更好地满足实际需求,为实际液压系统的设计和参数优化提供依据。     

砌块成型机设计参数的理论分析及验证

在分析砌块成型机结构和工作原理的基础上,建立了系统力学模型,通过对其振动系统动力学参数的理论分析,确立了设计参数的计算和选取方法,并通过实测进行了验证.     

砌块成型机设计参数的理论分析及验证

本文在分析砌块成型机结构和工作原理的基础上，建立了系统力学模型，通过对其振动系统动力学参数的理论分析，确立了设计参数的计算和选取方法，并通过实测进行了验证。     

高速注塑机注射部件设计及应用

针对高速注塑成型机特点,提出其注射部件的一般设计原则,并对注射部件动力源--蓄能器有关参数进行计算,分析注射部件液压系统原理,同时介绍高速注塑成型机的发展及应用.     

砌块成型机振动信号的自回归双谱分析

砌块成型机是一种快速制砖的自动设备。高阶谱分析是一种新的信号处理的有效技术,它可以定量描写信号间的非线性耦合,可以抑制噪声、保留信号的相位信息。采集砌块成型机工作过程中的随机振动信号,建立三阶累积量的时间序列的自回归模型和自回归双谱,分析了不同工况下砌块成型机的运行状况,研究机器运行的双谱特征。     

塑料中空吹塑机液压系统的设计与研究

通过分析大型中空成型工艺流程,对塑料中空成型机液压控制系统进行了设计,并对成型机壁厚控制系统的原理、构成及其特性进行了研究.该塑料中空成型机利用液压驱动,可方便、可靠地实现整机的自动工作循环,利用电液比例位置控制系统,可随意控制型坯的壁厚变化规律,保证吹膜后中空制品壁厚均匀.     

基于AMESim仿真技术的大型中空成型机锁模系统设计与研究

以大型储料式中空成型机的锁模系统为研究对象,利用AMESim仿真技术对其进行时域仿真分析。通过仿真分析得到了锁模缸活塞杆的位移、速度等变化曲线,根据仿真结果分析活塞受力与运动不稳定的原因,并对液压系统进行优化设计,有效避免了锁模系统开模过程中产生的液压冲击和机械冲击,减少了机械动作过程中的震动和噪声,提高了整个系统性能的稳定性和工作的可靠性。     

基于PLC控制的塑料注射成型机液压系统的设计

介绍一种由液压驱动、可编程控制器控制的塑料注塑成型机,并对其液压系统工作原理以及PLC控制注塑机的方法、硬件的选择和梯形图的绘制等进行了分析和设计。该设备具有效率高、质量好、能量省、成本低等特点。     

液压激振系统的应用研究

本文介绍了应用于再造大理石成型机的液压激振系统，并提出了应用转阀控制的系统其振动参数的合理选择方法。     

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。     

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 Short-Time Aging on the Pitting Corrosion Behavior of a Novel Lean Duplex Stainless Steel 2002

The effect of short-time aging in the temperature range between 400 and 1000 °C on the pitting corrosion behavior and mechanical property of a novel lean duplex stainless steel(LDSS) 2002 was investigated through the potentiostatic critical pitting temperature(CPT) tests and the Charpy impact tests. Both the pitting corrosion resistance and the toughness of aged specimens degraded due to the precipitation of detrimental secondary phases and the most significant reduction of CPT and impact energy emerged at 650 °C concurrently. The CPT of LDSS 2002 specimen aged at 650 °C decreased by 28 °C, and the impact energy dropped from 69 to 29 J/cm~2 compared with the solution-annealed sample. Transmission electron microscopy characterization showed that the main precipitates in LDSS 2002 were Cr_2N and M_(23)C_6 along the ferrite–austenite grain boundaries.     

Information for Contributors

正The Transactions of Nonferrous Metals Society of China,founded in 1991 and sponsored by The Nonferrous Metals Society of China,is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology,including mineral processing,extraction metallurgy,metallic materials and heat treatments,metal working,physical metallurgy,powder metallurgy,with the emphasis     

Preface

<正>We are pleased to present this Special Issue of Transactions of Nonferrous Metals Society of China containing selected papers from the First Asian Conference on Aluminum Alloys(ACAA-2013),held in Beijing,China,13–17 October 2013.This conference has been initiated,with approval of     

Information for Contributors

The Transactions of Nonferrous Metals Society of China, founded in 1991 and sponsored by The Nonferrous Metals Society of China, is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology, including mineral processing, extraction metallurgy, metallic materials and heat treatments, metal working, physical metallurgy, powder metallurgy, with the emphasis on fundamental science. It is the unique preeminent publication in English for scientists, engineers, under/post-graduates on the field of nonferrous metals industry. This journal is covered by many famous abstract/index systems and databases such as SCI Expanded, Ei Compendex Plus, 1NSPEC, CA, METADEX, AJ and JICST.     

INTRODUCTION TO PATENTS

The invention provides a method of making a mold which can reduce SOx generation rate while preventing decrease in hardening rate in the case of using sulfuric acid for a hardener composition. The method has a mixture step in which fire-resistant particles, a hardener composition and a binder composition are mixed to obtain a composition for a mold. The hardener composition contains sulfuric acid. In the mixture step, sodium carbonate is added. A molar ratio of the sulfuric acid to the sodium carbonate is 0.5 or more and 4.0 or less.     

China Foundry Week 2014

China Foundry Week, hosted by the Foundry Institution of Chinese Mechanical Engineering Society （FICMES） each year, is a large academic event in China. It is one of the ten high-impact activities sponsored by the Chinese Mechanical Engineering Society.     

17th Conference of Hydrodynamic and Electromechanical Control Engineering Call for papers

正1.Contents In order to promote the academic exchanges and technical communication of the research in the field of fluid power transmission and control,fluid control engineering specialized committee of the Chinese Society of Theoretical and Applied Mechanics will hold the 17th Conference of Hydrodynamic and Electromechanical Control Engineering on July 27-29,2014 in Tibet,Lhasa city.     

Formulas of Tension of Continuous Rolling Process

The development of computer controlled continuous rolling process calls for a mathematical expression that can express the inequality condition of "constant flow". Tension is the link of the continuous rolling process. From the condition of dynamic equilibrium, a differential equation of tension is given out. On the basis of the physical rules established from the industrial practice and experimental studies, the law of volume constancy, the linear relation of forward slip and tension, the state equation of continuous rolling, the formula of dynamic tension, and the formula of static tension have been obtained. These formulae reflect the functional relations between tensions, thickness, roll velocity, and time in the continuous rolling process. It is implied that the continuous rolling process is a gradually steady, controllable, and measurable dynamic system. An assumption of predicting the thickness of a steel plate using these tension formulae is also put forward.