关键词： BEDSORES   ANTIPSYCHOTIC drugs   ANALYSIS of variance   CORRELATION (Statistics)   FALLS (Accidents)   FRACTURES   LIFTING & carrying (Human mechanics)   MEDICAL care -- Evaluation   MULTIVARIATE analysis   NURSE administrators   NURSING care facilities   QUESTIONNAIRES   FINANCING of research   RESTRAINT of patients   STATISTICS   DATA analysis   SECONDARY analysis   TRANSPORTATION of patients   DATA analysis software   DESCRIPTIVE statistics   RISK factors   THERAPEUTIC use  

摘要： Objective: To determine associations between long-term care powered mechanical lift (PML) availability and mobility-related resident outcomes. Methods: Long-term care directors of nursing (N = 271) nationwide gave facility information on the PML availability and the lifting policy to which we linked data on mobility-related resident outcomes from the Centers for Medicare & Medicaid Services Minimum Data Set Quality Indicators. Results: Four of six Centers for Medicare & Medicaid Services derived resident indicators improved with the PML number but were maximal for the sit stand lift use. In facilities with the fewest lifts, 16% of residents had pressure ulcers and 4% were bedfast. In facilities with the maximum number of lifts, only 10% had pressure ulcers (P = 0.000) and 2% were bedfast (P = 0.002). Although falls were more frequent with more lift use, this risk was blunted by a comprehensive safe lift program. Conclusion: The PML availability is associated with benefits to resident outcomes, and accompanying risks are mitigated by safe lift policies.

关键词： Underactuated nonlinear mechanical systems   Sliding mode control   Trajectory tracking   Stabilization   Actuators dynamics  

摘要： The paper deals with a novel control algorithm for simultaneous stabilization and trajectory tracking of underactuated nonlinear mechanical systems (UNMS) with included actuators dynamics. Simultaneous stabilization and trajectory tracking refer to arbitrary chosen actuated and unactuated degrees of freedom (DOF) of the system. The proposed control approach can be applied both to the second-order nonholonomic systems and the systems with input coupling, while a general model of actuators dynamics includes electrical, pneumatic, and hydraulic drives. Control law is based on linear combination of two control signals, where the first signal is designed to separately control only actuated DOF, and second to separately control only unactuated DOF. Simulation example of rotational inverted pendulum driven by electrical DC motor is presented, showing the effectiveness of the proposed approach.

关键词： 内部控制   有效性   缺陷   改进建议  

摘要： 内部控制是当代企业管理的重要手段,是目前企业应对激烈的市场竞争、规避风险、实现战略目标而普遍采用的管理方法和手段。中国航天行业蓬勃发展、竞争加剧。内蒙航天动力机械测试所作为军工集团中的一家企业,在这样复杂和残酷的环境中要做强,构建内部控制体系是企业强烈的内在需求。虽然内蒙航天动力机械测试所正在逐步构建起自己的内部控制体系,但还是存在许多问题,需不断改善,以适应新形势的要求。 论文阐述了内部控制相关基础理论,结合相关理论,对内蒙航天动力机械测试所内部控制进行了较为全面的评价。在对内蒙航天动力机械测试所基本情况和内部控制制度运行背景详细介绍的基础上,从内部环境、风险评估、控制活动、信息与沟通、监督这五个方面描述了内蒙航天动力机械测试所内部控制运行情况,并针对现状进行了分析,对内蒙航天动力机械测试所内部控制状况进行了评价。最后,根据评价结果,分析内蒙航天动力机械测试所内部控制中存在的不足点,从内部控制构成要素角度提出了相应的改进措施。

关键词： Newton's Laws   active and reaction torques   d'Alembert's principle of dynamics  

摘要： In most discussions, the Principles of Dynamics are expressed using the force as a measure of mechanical interaction between the bodies. The intention of the paper is to extend the usual discussion on basic theorems, laws and principles in Dynamics of rigid bodies including the torque as another independent measure of mechanical interaction between the bodies. In D'Alambert's principle of Dynamics, beside the forces, the active and reaction torques are also included. The torque is introduced in the Euler-Newton equations for general motion of the rigid body. The General Equation of Dynamics is reformulated by including the virtual work of the torques on the virtual rotation. An additional view to Newton's Laws is also given.

关键词： 变截面辊弯成形   运动分析   动力学建模   机电系统动力学   矩形公式  

摘要： 本论文以国家科技支撑项目(高强钢先进成形技术及其应用)的子课题“三维辊弯成形装备研制”选题,开展高强钢三维辊弯成形生产线样机机械系统动力学分析的研究。所开展的工作为：建立样机机械系统动力学方程,通过工程算例,结合有限元仿真数据及实际成形试验数据对动力学方程进行求解,并对求解结果进行分析。 首先,本文对变截面辊弯成形工艺进行了研究,重点对变截面辊弯成形的道次数目、成形角度、轧辊的设计方法以及成形缺陷与解决方法进行了研究。 其次,本文在完成样机机械系统关键结构“双齿条单齿轮结构”的运动分析之后建立了样机机械系统的运动学方程。并根据变截面辊弯成形的工艺的特点,确定了成形机架的运动控制方式,为系统动力学方程的建立奠定了基础。 之后本文在完成机构转动惯量计算的基础上,利用机电系统动力学方法建立了系统的动力学模型：形成了以伺服电机的转矩为输入,以TRIP590变截面辊弯成形过程的成形力和成形力矩为载荷,以辊组伺服运动和转动为广义坐标的系统动力学方程。通过工程算例,在MATLAB软件中,利用ABAQUS有限元仿真分析得到的数据,绘制了负载力以及负载力矩与时间的关系曲线。通过成形试验,采集了伺服电机的输出转矩、齿条位置、轧辊伺服电机的角速度等数据。将有限元仿真数据及成形试验数据代入系统动力学方程当中,使用矩形公式对系统的动力学方程进行了求解,得到了伺服电机“角加速度-时间”以及“角速度-时间”的关系曲线,并依据系统的运动学方程求得了成形机架的位置-时间曲线以及转角时间曲线,验证了系统动力学方程的正确性。通过对求解结果的分析,本文得到了符合样机动态特性的结论,为后续三维辊弯成形生产线的研制提供了理论参考依据。

关键词： 轴向运动带   粘弹性   机械性   动力学建模  

摘要： 为进一步分析、研究稳定性特性,推导了粘弹性轴向运动带机械能变化方程.首先推导了考虑横向和纵向振动时轴向运动带中微元段的应变方程'接着以Kelvin-Voigt微分型应力-应变本构关系模拟带的粘弹性特性,利用Hamilton变分原理推导出运动带的横向和纵向梁振动方程；最后得到端支座分别为铰支座和固定支座时的粘弹性轴向运动带中机械能随时间的变化方程,分析研究了能量变化特性.

关键词： 钢架   屋架   整体   吊装  

摘要： 江苏安泰动力机械有限公司总装试验车间多榀钢屋架采用地面组合拼装，一次性整体吊装，这样既节约了施工成本，保证拼装精度，提高安全保障，又大大地缩短了施工工期，对以后的钢屋架吊装有参考意义。

关键词： 铁路   机械动力设备   三全管理  

摘要： 针对铁路机械动力设备管理存在的主要问题,提出以全方位、全过程和全员管理理念,创新管理方法和方式,提高设备管理水平的思路。

关键词： 机油变质   水垢   油底壳   柴油机   压燃发动机   油温过高   配合间隙   冷却器   冷却装置  

摘要： 1机油消耗量过大机油消耗量过大,致发动机功率下降、油底壳机油平面下降较快及排气冒蓝烟,一般由油封或衬垫处的渗漏或汽缸壁磨损过度而烧机油引起。主要原因:①活塞与汽缸间隙过大;②活塞环特别是油环弹性差;③缸套、活塞环过度磨损,活塞环被粘住、对口或扭曲环装反;④活塞环与环槽边隙和侧隙过大或活塞上油环回油孔被积炭阻塞;⑤增压柴油机涡轮增压器弹力密封装置失效;⑥气门杆与导管配合间隙过大或过小致使油封失效。

关键词： Midazolam   Mechanical ventilation   Pharmacokinetics   Continuous infusion   Intermittent bolus doses  

摘要： There is no randomized study carried out in order to compare their pharmacokinetic parameters although midazolam, as a sedative, has been widely administered via continuous infusion as well as intermittent bolus doses in mechanically ventilated critically ill patients. We prospectively investigated the effect of these two principal methods on pharmacokinetic parameters in 23 of mentioned patients (16 males, 7 females) with the mean (+/- SD) age of 41.22 +/- 17.5. All patients received total dose of 72 mg throughout the test days, 9 of whom received 1 mg/h (continuous infusion) and the rest obtained 4 mg / 4 h (intermittent bolus doses). Blood samples were collected at 8 and 4 h prior to the end time of drug administration (zero time), zero time and 4, 8, 12, 20 and 30 h after it. APACHE (Acute Physiology and Chronic Health Evaluation) II required data was recorded daily and the patients' mean score was 16.26 +/- 4.38. The mean (+/- SD) value of pharmacokinetic parameters of Midazolam in continuous infusion and intermittent bolus doses methods were as follows: (t1/2 = 17.88 +/- 14.65 h, Cl = 21.80 +/- 14.95 L/h) vs. (t1/2 = 19.74 +/- 12.45 h, Cl = 29.43 +/- 19.45 L/h). Volume of distribution (Vd) was measured in continuous infusion group which was 612.58 +/- 582.93 L. The calculated clearance and half-life were found not to be significantly different (p < 0.05). The patients might be exposed to similar undesired effects due to the large volumes of distribution following the administration methods studied.