关键词： 电动汽车   电磁制动   耦合制动   制动力分配   制动能回收  

摘要： 针对现行电动汽车再生制动的不足,提出一种新型电磁机械耦合再生制动系统(electromagnetic-mechanical coupled regenerative braking system,EMCB),并对其进行动力学分析和耦合机理研究;基于EMCB系统和理想制动力分配曲线提出一种制动力分配策略,构建EMCB系统模型和控制策略仿真系统,应用Car Sim&Simulink联合仿真平台,以有、无滑移率控制的紧急制动工况为例,对制动能回收、制动稳定性和制动舒适性等进行对比研究和验证分析。研究结果表明,所提出的制动力分配策略不仅实现中低制动强度下实际制动力分配曲线与理想I曲线高度吻合,还满足高制动强度下制动效能的需求,即保证了制动稳定性和制动舒适性,又提高了能量回收效率,有效增加了电动汽车的续驶里程,为进一步获得良好的防抱死制动系统(ABS)、电子制动力分配系统(EBD)、电子稳定系统(ESP)等控制性能奠定了基础。

关键词： 吉林石化公司   汽机   密封环   车间   王志  

摘要： 王志久是吉林石化公司动力二厂汽机车间一名机械师,1.8米的个头,身材微胖,黑黝黝的国字脸上,总是挂着和蔼的笑容,大家都亲切地叫他'老王'。屈指算来,再有个6月,老王就要退休了。精打细算过日子是他那个年代人的特点,老王就是车间里最'抠'的那个人。腊月里,车间检修滤水器时拆卸下18对螺栓。

关键词： Algal growth dynamics   Mechanistic model   Photobioreactor   Nutrient uptake   Algal excretions  

摘要： A comprehensive mechanistic model for describing algal growth dynamics in a photobioreactor was developed in this work with state of the art understanding and realistic assumptions for major associated processes. The model included 27 state variables related to various algal processes. This model was validated with extensive experimental data obtained from independent growth experiments in batch reactors, and was able to simulate system performance reasonably well. The comprehensive nature of the formulation also highlights the complex inter-relationship between all processes, and provides a tool for gaining more systematic insights into algal behavior in photobioreactors and other such systems. (C) 2017 Elsevier Ltd. All rights reserved.

关键词： Indoor dispersion   CFD   Mixing   Pollutant   Safety   Automation  

摘要： Understanding mixing times for transient pollutants in mechanically ventilated rooms is important for resilience and safety planning for accidental releases of toxic material. There is a lack of information on the ability of simple models available to predict these times for ventilated spaces with different geometries and ventilation configurations. Three analytical mixing time models, including a novel jet transit based approach, have been selected for comparison with computational fluid dynamics (CFD) predictions for a wide range of cuboidal rooms with ceiling ventilation. A modelling tool has been developed, using open source and open source based software, to automatically build and run a large number of Reynolds averaged Navier-Stokes CFD models. The tool has been used to study the dependence of the chosen mixing metrics on room geometry and ventilation parameters, such as the air change rate, for a transient pollutant entering the room via the ventilation system. The room volume, shape, air change rate and vent layout were varied for each room using a Sobol sequence experimental design. The CFD tool has been used to assess the validity of the analytical mixing time models and to derive parameters for the scenarios of interest. Crown Copyright (C) 2017 Published by Elsevier Ltd.

关键词： Molecular dynamics  

摘要： In this article, we present two principal stimuli that affect the deformation response: additional covalent crosslinking and external deformation. Additional crosslinking leads to hybrid gels which show improved toughness in comparison to the physical gels. The article considers also the change of response of the model as a consequence of external mechanical loading. In this case, the structural changes driven by deformation induce permanent structural changes owing to extensive stretching analogous to filament drawing in spider silk or collagen. Almost identical atomistic configurations are transformed into various materials, depending on the stimulus and the conditions. The intensity of stimuli can be regulated also in real materials. The degree of covalent crosslinking can be regulated for example by ultraviolet irradiation. The permanent changes are observed only when the stretching ratio is sufficiently large and stretching is quick. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

关键词： 工程机械臂   系统结构   动力学  

摘要： 现如今计算机和产品设计相关方面的技术发展迅速,机械产品逐渐朝着高速、精确、环保的方向发展,对机械产品特性的研究成为如今设计机械产品的关键,国内外相关领域都对其投入了较大的关注力度。工程机械臂是工程机械中十分重要的元件,它的动力学性能对整个工程机械的作用发挥都有着极其重要的作用。工程机械的工作环境往往十分恶劣,因此工程机械臂所受的负荷情况十分复杂,为了保证机械臂工作的安全性与可靠性,本文对工程机械臂的结构动力学及特性进行了简要分析。

关键词： 机械臂动力学   建模   控制   仿真  

摘要： 随着航天及机器人领域的迅猛发展,对机器人的应用研究越来越广泛,机械臂在工业、国防等应用领域中占有十分重要的地位。尤其是对机器人的基础核心部分的研究,引起了许多国内外学者和专家的兴趣,由于工人成本的提高,工人劳动保护意识的增强以及对产品质量要求的提高,工业机器人应用已经开始深入生产制造环节的各个领域。机器人也逐渐出现在人们的生活中,它们具有可靠的运动精度、高度的灵活性,并能长期稳定工作,可以在人类无法工作的环境中代替人的工作,以保护人身安全,对提高生产效率和产品质量,实现工业生产的机械化和自动化,起到了十分重要的作用,因而广泛应用于机械制造、冶金、电子、轻工和原子能等领域。本文就机械臂动力学建模及控制仿真进行简单的阐述。

关键词： 动力学   机械结构设计   应用  

摘要： 运动力学主要包含诸多力学原理,而且很多机械设计流程往往需要运用到这些力学原理,以保证设计的科学性。特别是对于以往机械设计构造而言,静态力学的概念运用相对较为广泛,但是在实际运作过程中,机械设备往往是一个动态运动的过程,因而研究对应的动态力学在机械设备构造设计中的运用,也显得格外重要。而就此,笔者将通过本文,就运动力学在机械结构设计中的应用及研究方面入手,将进行具体的分析和研究。

关键词： 信息管理系统   应用   铁路机械设备  

摘要： 在运输科技飞速发展的过程中,铁路运输得到了越来越多的重视,这充分显示出社会科技的迅速发展。当前铁路提速、载重提高等技术的不断创新使得与之相关的铁路设备及检修质量不断增强,从而与铁路运输的发展切合。本文在现代信息技术的有效支持下,对铁路机械动力设备技术信息管理系统的组成、特点、功能、应用都进行有效的分析。

关键词： Anelastic deformation   Cell adhesion   Cell mechanics   Viscoelasticity  

摘要： Cell adhesion is an essential biological process. However, previous theoretical and experimental studies ignore a key variable, the changes of cellular volume and pressure, during the dynamic adhesion process. Here, we treat cells as open systems and propose a theoretical framework to investigate how the exchange of water and ions with the environment affects the shape and dynamics of cells adhered between two adhesive surfaces. We show that adherent cells can be either stable (convex or concave) or unstable (spontaneous rupture or collapse) depending on the adhesion energy density, the cell size, the separation of two adhesive surfaces, and the stiffness of the flexible surface. Strikingly, we find that the unstable states vanish when cellular volume and pressure are constant. We further show that the detachments of convex and concave cells are very different. The mechanical response of adherent cells is mainly determined by the competition between the loading rate and the regulation of the cellular volume and pressure. Finally, we show that as an open system the detachment of adherent cells is also significantly influenced by the loading history. Thus, our findings reveal a major difference between living cells and nonliving materials.