关键词： 运动力学   机械结构   设计应用  

摘要： 伴随着机械制造业在国内经济生产领域中的逐渐开展,中国在国际市场中拥有了"世界工厂"的称呼,并且在机械技术的发展革新中逐步深化,实现了科学与技术之间的进一步结合。在机械结构的设计应用中,运动力学作为机械科学和物理学中的主要连接点,对于机械结构的生产革新,无疑能够起到非比寻常的引导功能和借鉴价值,并且在技术革新的进程中,起到工作效率和产品质量的双重提升。因此,文章通过对运动力学的解析,辅之以机械结构设计要素的归纳和总结,有助于实现针对运动力学在机械结构设计中的应用态势的洞悉与掌握。

关键词： 糖尿病性心肌病   机械功能   心肌运动   超声心动图技术   糖尿病大鼠   血流动力学   病理生理机制   心脏并发症   左心室内压   cardiomyopathy  

摘要： 糖尿病是全世界发病率和致死率较高的慢性内分泌疾病。糖尿病性心肌病（diabetic cardiomyopathy,DCM）是糖尿病患者心肌细胞处于高糖、高脂环境下所引起的心脏并发症。自1974年Hamby等[1]首次提出DCM概念以来,DCM已被临床公认为糖尿病常见心脏并发症之一。DCM具有复杂的病理生理机制及电机械功能异常,因早期临床表现隐蔽而容易被忽视。

关键词： 船舶   动力机械   螺旋桨   状态监测   推进器  

摘要： 螺旋桨是船舶动力机械的重要组成部分,因此对于螺旋桨状态的监测是整个设备状态监测的重要内容。文章首先对船舶动力机械中的螺旋桨进行了介绍,然后分析了船舶动力机械中对螺旋桨的具体检修内容,最后具体探讨了船舶动力机械中螺旋桨的养护措施。

关键词： 呼吸功能不全   呼吸,人工   儿茶酚胺类   血流动力学   镇静  

摘要： 目的观察2种镇静方法对呼吸衰竭机械通气患者血儿茶酚胺水平及血流动力学的影响。方法选取2014年1-12月需行气管插管机械通气的呼吸衰竭患者54例,分为对照组（C组）、丙泊酚联合芬太尼组（P＋F组）、咪达唑仑联合芬太尼组（M＋F组）,每组18例。分别在插管前、气管插管（镇静）后30 min、插管后3 h检测血儿茶酚胺水平,同时观察对应时间点的心率、血压。结果与插管前比较,C组患者气管插管后30 min的血儿茶酚胺水平、心率及血压显著升高,P＋F组与M＋F组插管后30 min、3 h血儿茶酚胺水平、心率及血压显著降低,差异均有统计学意义（P〈0.05）。与C组插管后30 min比较,P＋F组与M＋F组血儿茶酚胺水平、心率及血压明显降低,差异均有统计学意义（P〈0.05）;与M＋F组插管后30 min、3 h比较,P＋F组相应时间点的血儿茶酚胺水平和心率无较大变化,差异均无统计学意义（P〉0.05）,但血压显著降低,差异有统计学意义（P〈0.05）。结论气管插管机械通气能引起患者血儿茶酚胺水平明显上升,镇静治疗能有效降低气管插管机械通气患者血儿茶酚胺水平,丙泊酚联合芬太尼与咪达唑仑联合芬太尼镇静均能有效减轻患者应激反应,但咪达唑仑联合芬太尼镇静对患者血压影响较小。

关键词： 机械动力学   研究生   教学改革   动力学建模方法   案例教学  

摘要： 机械动力学是我校研究生的基础理论和实践应用紧密结合的一门学位课,为配合重庆机器人产业的发展,充分利用我校机械、车辆专业多年积累起的丰厚教学资源,将机械动力学教学内容划分为四个教学板块,每个板块由专业教师采用工程案例教学,同时注重仿真软件在课堂上的应用和实验教学,为机械类研究生建立系统的专业知识体系,从而提高教学质量。

关键词： 运动力学   机械结构设计   应用  

摘要： 随着现代工业的发展,机械产品的需求越来越大,其质量要求也越来越高。对于机械结构设计而言,在一定程度上有着十分重要的影响作用。根据市场需求与质量要求,机械产品的结构设计需要从不同的教学进行分析,从而保证机械使用过程中的高效性与安全性。两者在一定程度上决定机械产品的质量标准。本文从运动力学的角度,探讨机械结构设计中,运动力学的应用,并对机械结构设计提出相应的改进意见。

关键词： 灵巧手   动力学   正逆解  

摘要： 全驱动灵巧手的工作系统既是多变量的非线性自动控制系统,同时还是复杂的动力学耦合系统。研究灵巧手的动力学就是分析抓取力和控制的基础。对全驱动灵巧手进行动力学分析是研究机械爪的抓取力的重要基础。文章采用牛顿欧拉方法对灵巧手进行动力学分析。

关键词： 4-Dihydropyrano[c]chromene   Sodium acetate   4-Nitrobenzaldehyde   Malononitrile   4-Hydroxycoumarin   Kinetics   Mechanism  

摘要： Sodium acetate was applied as an efficient catalyst for the one-pot, three-component condensation reaction consisting of 4-nitrobenzaldehyde 2, malononitrile 3, and 4-hydroxycoumarin 1. For the first time, the kinetics and mechanism of the reaction has been investigated spectrally. The second-order rate constant dependency on the temperature was in agreement with the Arrhenius and Eyring equations. The kinetic and thermodynamic parameters of the reaction were calculated. Furthermore, useful information was obtained from studies of the solvent and concentration effects on the reaction rate. The results showed that the second step of the reaction mechanism is a rate-determining step. The proposed mechanism was also confirmed according to the obtained results and the steady-state approximation.

关键词： Anatomy   Nanogenerators   Energy   Power   Batteries  

摘要： In this issue of Acs Nano, Tang et al. investigate the ability of a triboelectric nanogenerator (TENG) to self-power a low-level laser cure system for osteogenesis by studying the efficiency of a bone remodeling laser treatment that is powered by a skin-patch-like TENG instead of a battery. We outline this field by highlighting the motivations for self-powered biomedical systems and by discussing recent progress in nanogenerators. We note the overlap between biomedical devices and TENGs and their dawning synergy, and we highlight key prospects for future developments. Biomedical systems should be more autonomous. This advance could improve their body integration and fields of action, leading to new medical diagnostics and treatments. However, future self-powered biomedical systems will need to be more flexible, biocompatible, and biodegradable. These advances hold the promise of enabling new smart autonomous biomedical systems and contributing significantly to the Internet of Things.

关键词： Graphene   Graphene nanoribbon   Mechanical responses   Molecular dynamics  

摘要： We performed MD simulations of nanoindentation on a single layer graphene nanoribbon in order to obtain the tip-position-dependent mechanical properties of the graphene nanoribbon. A correlation between the load and the indentation depth was constructed. Also, the bending rigidity, the Young's modulus and the strength of the graphene nanoribbon were obtained. Our results yielded the tip position dependence of the Young's modulus for the graphene nanoribbon. The Young's modulus of the graphene nanoribbon was calculated by using the lowest value when the tip's position was in the center region of the graphene nanoribbon, and as the tip's position moved away from the center, the Young's modulus increased. These results gave interesting insight as to why the Young's moduli obtained from experiments were different from one another. The change in the mechanical properties of the graphene nanoribbon due to the change in the tip's position can also lead to a novel graphene-based nanoelectromechanical device.