关键词： 运动平台   运动学   动力学   ADAMS  

摘要： 应用机械系统动力学仿真分析软件ADAMS,对驾驶模拟器运动平台进行了运动学和动力学仿真研究.建立了6自由度Stewart型运动平台的虚拟样机模型,进行了仿真计算,得出支腿作动器行程和驱动力的变化曲线.仿真结果为运动平台的设计提供了依据.

关键词： 机械动筛跳汰机   分选效果   曲柄连杆机构   动力提升机构   急回特性  

摘要： 分析了影响动筛跳汰分选效果的主要原因,从研究动筛曲柄连杆机构急回特性入手,对机械式动筛跳汰机动力提升机构及动筛机构关键部位进行了改进和完善,设计了新型动力提升装置,为进一步研究及指导大型动筛跳汰机的设计开发奠定了基础。

关键词： 农业机械   劳动力   替代弹性   CES生产函数  

摘要： 基于CES生产函数,利用我国1978-2008年的统计数据,实证分析了粮食生产中农业机械总动力与劳动力投入之间的关系。结果表明:单位播种面积农业机械总动力与劳动力投入之间确实具有一定的替代关系,但目前农业劳动力投入量依然是影响我国粮食生产产量的重要因素,而农业机械替代劳动的作用不大。

关键词： 混合动力   工程机械   负荷特性  

摘要： 为了使工程机械取得更好的节能减排效果,通过对工程机械混合动力技术发展现状进行分析,并探讨了工程机械混合动力系统的关键技术,得出动力参数的匹配、能量的回收与控制及系统和关键元件的可靠性是影响混合动力系统性能的关键。

关键词： 安全操作规程   安全启动   动力机械   安全管理人员   农业生产   农机事故   宣传教育   安全生产  

摘要： 在农业生产中，由于不按照农业安全操作规程去作业而造成的农机事故约占事故总数的60％以上。这些事故的发生，给生产、经济带来不应有的损失，甚至造成伤亡。安全管理人员必须首先严格遵守有关安全的操作规程，并进行广泛的宣传教育，加强安全管理，确保安全生产。在整个农业生产事故中，由于动力机械的不正确操作造成的事故率较高。

关键词： 动力机械设备   故障诊断   发展趋势  

摘要： 介绍了动力机械设备故障诊断技术,分析了制约其发展的主要因素,阐述了动力机械设备故障诊断技术的发展趋势。

关键词： 机械动力学   学术会议   征文范围   中国   专业委员会   动力学理论   机床动力学   工程学会  

摘要： 由中国振动工程学会机械动力学专业委员会主办的＂2011中国机械动力学学术会议＂将于2011年7月29—31日在杭州召开。征文范围：机械动力学理论与方法;机床动力学;动态测试与信号分析;机械系统故障诊断;

关键词： Inflow cannula   Mechanical circulatory support   Pressure loss   Bridge to decision  

摘要： Recent progress in the development of implantable rotary blood pumps realized long-term mechanical circulatory support (MCS) for bridge to transplant, bridge to recovery, or a destination therapy. Meanwhile, a short-term MCS system is becoming necessary for bridge to decision. We developed a novel inflow cannula for the short-term MCS system, which gives sufficient bypass flow with minimal invasion at insertion, and evaluated its hydrodynamic characteristics. The novel inflow cannula, named the Lantern cannula, is made of elastic silicone reinforced with metal wires. The cannula tip has six slits on the side. This cannula tip can be extended to the axial direction by using an introducer and can be reduced in diameter, and the Lantern cannula enables easy insertion into the left ventricle apex with minimal invasion. The sufficient bypass flow rate can be obtained due to low pressure loss. Moreover, this Lantern shape also resists suction complication around the cannula tip. The pressure loss through the Lantern cannula was measured using a mock circulation and compared with two commercially available venous cannulae (Sarns4882, Terumo, Tokyo, Japan and Stockert V122-28, Sorin Group, Tokyo, Japan), which have almost same diameter as the Lantern cannula. Moreover, the flow patterns around the cannula tip were numerically analyzed by computational fluid dynamics (CFD). Acute animal experiment was also performed to confirm the practical effectiveness of the Lantern cannula. The pressure loss of the Lantern cannula was the lowest compared with those of the commercially available venous cannulae in in vitro experiment. CFD analysis results demonstrated that the Lantern cannula has low pressure loss because of wide inflow orifice area and a bell mouth, which were formed via Lantern shape. The highest bypass flow was obtained in the Lantern cannula because of the low pressure loss under pulsatile condition in in vivo experiments. The Lantern cannula demonstrated superior hyd

关键词： biosensors   DNA detection   electrochemistry   electron transfer   ferrocene   peptide nucleic acids  

摘要： N-Terminally ferrocenylated and C-terminally gold-surface-grafted peptide nucleic acid (PNA) strands were exploited as unique tools for the electrochemical investigation of the strand dynamics of short PNA(.DNA) duplexes. On the basis of the quantitative analysis of the kinetics and the diffusional characteristics of the electron-transfer process, a nanoscopic view of the Fc-PNA(.DNA) surface dynamics was obtained. Loosely packed, surface-confined Fc-PNA single strands were found to render the charge-transfer process of the tethered Fc moiety diffusion-limited, whereas surfaces modified with *** duplexes exhibited a charge-transfer process with characteristics between the two extremes of diffusion and surface limitation. The interplay between the inherent strand elasticity and effects exerted by the electric field are supposed to dictate the probability of a sufficient approach of the Fc head group to the electrode surface, as reflected in the measured values of the electron-transfer rate constant, k(0). An in-depth understanding of the dynamics of surface-bound PNA and *** strands is of utmost importance for the development of DNA biosensors using (Fc-)PNA recognition layers.

关键词： Acrylonitrile-butadiene rubber (NBR) composites   Bentonite   Rheological behavior   Mechanical properties   Vulcanization kinetics  

摘要： The effect of the incorporation of bentonite (BT) untreated and treated with octadecylamine on the rheological behavior and vulcanization kinetics of NBR was investigated. Mechanical properties were also evaluated. Decreases in the optimum cure time (t(90)) and in the scorch time (t(S2)) and a notorious improvement in mechanical properties were found when treated BT was employed. From the vulcanization kinetics analysis, we can infer that the curing rate is superior for the treated BT composites, while the reaction orders point out the dependency of the vulcanization reaction on the initial reactants if compared to the catalytic effect of the reaction products.