精益生产方式拉动生产系统设计程序的研究

将精益生产方式拉动生产系统的支撑条件分作设计性条件和改善性条件，并在仅考虑设计性条件的情况下对精益生产方式拉动生产系统的设计程序进行了初步的总结和研究，建立和阐述了相应的程序。     

浮筏隔振系统的非共振响应分析

建立了筏架和基础板均为弹性体的浮筏动力学方程,分析了隔振器的非线性刚度对系统动态特性的影响。在线性条件下,通过刚柔耦合软件仿真,验证了建模理论的合理性,并通过功率流方法,对结构能量的传递进行了分析。在非线性条件下,隔振器具有立方非线性的刚度项,利用多尺度法研究系统发生内共振等条件,同时通过数值方法计算分析了系统在单频和多频激励下的非共振响应。研究结果表明:线性和非线性条件下的柔性浮筏隔振系统,其动力学特性区别明显。非线性条件下,筏架的刚柔程度显著地影响系统特性,而线性条件下的低频段,该影响较小。同时非线性条件下的系统存在较为复杂的谐波及倍周期现象。     

非弹性碰撞振动系统的首次穿越分析

对高斯白噪声激励作用下的非弹性碰撞振动系统的首次穿越问题作了分析,得到了非弹性碰撞振动系统的条件可靠性函数和相应的条件概率密度函数。不同于以往碰撞物理模型,非弹性碰撞作用采用了修正赫兹接触模型。首先,基于能量耗散平衡法,将碰撞振动系统转化为不含碰撞的等效非线性系统。其次,应用基于系统能量的随机平均法,得到关于系统总能量的平均伊藤随机微分方程。然后,建立条件可靠性函数的控制方程及相应的初边界条件,并数值求解。最后,分析了不同系统参数情形下条件可靠性函数及相应的条件概率密度函数的变化规律。该方法可有效分析非弹性碰撞振动系统的首次穿越问题,数值分析结果表明较大的阻尼系数可提高系统可靠性,而较大的激励强度则往往增加发生首次穿越的概率。     

一类三次系统无穷远点的中心条件与赤道极限环分支

本文研究了一类三次系统无穷远点的中心条件与赤道极限环分枝问题。通过将实平面系统转化为复系统研究,给出了计算无穷远点奇点量的递推公式,并在计算机上用Mathematica推导出该系统无穷远点前七个无穷远点奇点量,进一步导出了无穷远点成为中心的条件和七阶细焦点的条件,得到了三次系统无穷远点分支出七个极限环的一个实例。     

基于离散呼吸子理论的靶能量传递研究

研究了一个具有非线性能量阱的两自由度线性振子耦合系统,确定了其产生靶能量传递的条件和传递频率。建立了无量纲形式的振动方程,利用复变量——平均法推导了保守系统的慢变动力流和哈密顿函数。基于哈密顿力学和相空间中的离散呼吸子理论确定了系统产生靶能量传递的质量比条件和初值条件,并采用椭圆积分计算得到靶能量传递的频率。通过数值仿真验证了有阻尼系统中靶能量传递的不可逆性。     

Lyapunov指数与混沌同步的计算研究

条件Lyapunov指数是混沌系统同步的重要指标，文中以已知方程的Lyapunov指数谱计算方法为基础，通过数值计算考察了参考，同时，用其计算了混沌同步系统的条件Lyapunov指数，并研究了混沌同步系统的稳定性。     

一类非线性切换系统状态观测器的设计

考虑了一类标称系统存在共同Lyapunov函数的不确定非线性切换系统的鲁棒状态观测器的设计问题。系统具有满足Lipschitz条件的非线性项,不确定项不满足匹配条件,设计出了该系统在任意切换策略下的鲁棒渐近状态观测器。仿真结果表明所设计观测器的有效性。     

县市级电视台数字电视条件接收原理及实现方案

本文在分析数字电视条件接收系统基本理论和条件接收系统基本原理基础上,重点研究了数字电视条件接收系统机顶盒上的实现问题,并分别从系统对于数字电视机顶盒的要求、CAS方案选择及移植等方面进行了深入阐述。     

公度时滞系统的有理镇定补偿器

讨论了具有公度时滞系统的有理函数镇定补偿器的条件和算法．在不含时滞的名义系统为最小相位的条件下，可设计一簇常数补偿器镇定具有公度的无限时滞系统；在不含时滞的名义系统可强镇定的条件下，可设计一簇有理函数补偿器镇定具有公度的有限时滞系统．给出了相应时滞补偿器的具体算法．设计者可从这簇补偿器中选取一个最优的补偿器满足特定的设计要求．     

线性受控系统的反馈时滞可辨识性

该文研究具有不同位移和速度反馈时滞的单自由度线性系统辨识问题。分析了在任意时滞条件下系统频响函数出现等值的条件,指出若对系统施加频率为ω的简谐激励,则通过系统响应辨识出的时滞可能与系统的真正时滞相差2pπ/ω,其中p为正整数。对短时滞的可辨识性进行了分析,给出了若干可辨识条件。通过系统模态参数关于时滞的灵敏度,指出了基于实验模态参数辨识时滞的途径。     

Flow injection analysis of L-lactate with enzyme amplification and amperometric detection

A flow injection analysis method for the determination of the lactate anion with enzyme amplification and amperometric detection is described. The system utilizes an oxygen electrode for measurement of changes in the oxygen concentration in the flow stream. Two enzymes, lactate oxidase and lactate dehydrogenase, were randomly coimmobilized on aminopropyl controlled-pore glass (AMP-CPG) and packed into a reactor. beta-NADH was used as a coenzyme for the regeneration of lactate from pyruvate. The experimental conditions for the determination of the lactate anion were studied for this system by the simplex and the univariant methods. The results obtained under these two conditions were compared. The simplex experimental condition yielded a calibration curve whose linear portion had a slope that was 1.2 times greater than that of the linear portion of the curve obtained under univariant conditions. The limit of detection under simplex condition was 1.19 x 10(-7) M vs 3.29 x 10(-7) M lactate under univariant conditions. The relative standard deviation obtained for this system at 6 x 10(-6) M lactate (n = 10) was about 2.5% under simplex conditions and 3.6% under univariant maximization conditions.     

Performance comparison between the combined R134a/CO2 heat pump and cascade R134a/CO2 heat pump for space heating

In this paper, the performance of combined R134a/CO₂ and cascade R134a/CO₂ systems for space heating was studied and compared under specific operating conditions. A mathematical model was developed for this purpose and was verified by experimental data. The effects of key parameters such as water feed temperature, water supply temperature and ambient temperature on the performance of the two systems were further investigated. Results showed that cascade and combined systems had different preferable application conditions. The cascade system performed better at low ambient temperatures while the combined system performed better under conditions of high ambient temperature and high hot water temperature differences between the system inlet and outlet. A correlation was established and an operating condition coefficient was proposed to determine which system should be used for any given set of working conditions.     

光伏发电系统发电功率预测

为解决光伏发电系统发电功率在不同条件下误差较大问题,提出光伏发电系统发电功率预测新方法。通过分析光伏发电系统结构,研究光伏发电系统发电功率影响因素;以季节和天气类型作为历史样本选取样本源,针对气象部门提供的预测日分时气象数据在历史数据库中寻找相似数据点作为历史样本;依据历史样本构建离线参数寻优数据总集,使用核函数极限学习机算法构建发电系统发电功率预测模型,通过粒子群算法优化模型参数。实验结果表明：所提方法在不同条件下预测太阳能光伏发电系统发电功率的平均绝对百分比误差分别为1.47%和6.39%,光伏组件在综合异常条件下发电功率预测误差相对变化均低于1%,证明所提方法满足实际预测要求。     

微粒捕集器系统数值模拟研究

利用模型分析微粒捕集器净化效率、排气阻力和微粒捕集器寿命的变化规律,对微粒捕集器系统进行数值模拟研究。由于微粒捕集器的实际性能受实际道路工况的影响很大,对实测的车辆道路工况试验数据进行整理和统计分析,在此基础上建立整个带微粒捕集器的柴油机排气系统的数学物理模型,并对影响系统寿命的主要参数进行仿真分析,为微粒捕集器与柴油机的匹配和集成奠定一定的基础。     

基于关联规则的复杂系统稳态运行参数优化

针对系统运行过程中,工况切换可能导致系统运行参数目标值的跃变,进而引发系统运行不稳定的问题,本文提出一种基于关联规则的变工况运行参数稳态优化方法,改进了原有的关联规则挖掘策略,将历史工况作为变工况关联规则挖掘的输入条件之一,以系统运行状态稳定为约束,优化稳态运行参数目标值,并讨论了变工况下系统的准稳态运行条件.以某商场...     

Time-correlated single photon counting and optical measurement systems for studying single fluorescent emitters under high vacuum conditions

In this paper, we introduce a modified inverted microscope system in which an objective with high NA (0.95) is located under high-vacuum conditions, and a time-correlated single photon counting system is used along with a modified photomultiplier tube for the characterization of single emitters under high-vacuum conditions. The modified inverted microscope system is designed to be simple, compact, and easy to handle. As an example, the optical properties of individual colloidal semiconductor nanocrystals (CdSe/ZnS) were studied by using these systems.     

Quantitative safety assessment of the ventilation recirculation system in an undersea mine

This paper describes a quantitative safety study carried out on a system which monitors the environmental conditions in an undersea mine. Of particular importance are the concentrations of methane and carbon monoxide present in the mine. Although the presence of these gases is of concern in all mines it is of particular concern in this undersea mine since up to 37 per cent of the return air of the ventilation system is recirculated. When high methane or carbon monoxide levels are detected recirculation is halted. Fault trees were constructed to represent two system failure modes for each of the trip conditions; failure to trip on demand and spurious trip. These logic diagrams were then analysed to produce the minimal cut sets and the probabilities for the system failure events. From this prediction of system performance the degree of improvement attainable by changing the system design, component repair times or test frequencies was investigated.     

经典边界条件黏弹性Pasternak地基上Bernoulli-Euler梁横向自振特性分析

自振特性在结构的动力分析中具有重要的意义。将回传射线矩阵法(MRRM)推广到地基梁自振特性的研究中,通过节点力平衡和位移协调方程及对偶局部坐标系下单元相位关系,建立两端简支、两端自由、两端固支、简支-自由、简支-固支及固支-自由这六种边界条件下黏弹性Pasternak地基上的Bernoulli-Euler梁的回传射线矩阵,进而得到其频率方程。根据单一局部坐标系下的边界条件,推导出模态函数解析表达式,进一步根据正交归一化条件求解模态函数表达式中的未知参数。通过具体算例验证了回传射线矩阵法求解的正确性,并对不同边界条件下的自振频率、衰减系数及模态函数进行了分析。为黏弹性地基梁的振动特性研究提供理论基础。     

Observation of plastoquinone kinetics in photosystem II from delayed fluorescence measurements

Attempts to account for the variations in photosystem II (PSII) under general conditions result in nonlinear and cumbersome models that are difficult to validate and render few insights about the system kinetics. In this research, the authors experimentally show that under certain conditions, linear-system techniques could be applied to advantage for probing some basic kinetic characteristics of the plastoquinones (PQs). The PQ redox states of the reaction centres were represented in a conditionally linear model structure with delayed fluorescence (DF) as a measurable output. DF data were acquired for different plant samples and conditions. After least-squares parameter optimisation, not only could the model closely describe the measured DF, but more significantly, the estimated parameters correctly reflected the expected changes induced by drought or [3-(3,4-dichlorophenyl)-1,1-dimethylurea] (DCMU) stress. Analysis showed that for short-pulse illumination, the PQ kinetic states of the reaction centres in an initially dark-adapted plant leaf can be represented as a time-invariant bilinear system in a five-dimensional state space. The system becomes linear for constant illuminations, but the system matrix and the kinetic behaviour are illumination dependent. In particular, the system behaves differently between lights-on and lights-off conditions. The simplicity of the model structure, nonetheless, permits observation and analysis of the PQ kinetics of PSII reaction centres from DF measurements by using linear-system techniques.     

Dynamic blood cell contact with biomaterials: validation of a flow chamber system according to international standards

The increasing number of patients requiring prosthetic substitution of segments of the vascular system strongly supports the need to optimize a relevant, standardized testing panel for new materials designed for synthetic vascular prostheses. The ISO gives the standard requirements for testing biomaterials provided for implantation. Our primary interest was the establishment of a reliable in vitro panel as a useful and relevant screening system for vascular implant devices to evaluate blood/device interactions under flow conditions. The aim of the present study was to evaluate influences of different flow conditions on blood cell–biomaterial interactions with special emphasis on the interactions of human granulocytes (PMN) and polymeric surfaces. PMN were isolated and vital cells were quantified by flow cytometrical analysis directly before, as well as immediately after the experiments. The viscosity of the final cellular suspension was analysed by using a computerized cone-plate rheometer. As reference materials we used FEP-teflon, PVC-DEHD, PU, PP and PE. Dacron and ePTFE synthetic vascular protheses were tested in a comparative way to those references. The adhesion processes were observed over a period of 40 minutes under arterial (shear stress 0.74 Pa) and venous (shear stress 0.16 Pa) flow conditions in a parallel plate flow chamber system under highly standardized conditions and laminar flow. The cells were observed with the help of inverse light microscopy. Cell behaviour was recorded and analysed in both analogue (video) and digital (imaging system) modes. Samples of the cell suspensions were obtained at regular time intervals and analysed by enzyme linked immuno sorbent assay (ELISA) to quantify LTB4 release. Irrespective of the material, approximately 3 to 4 times more PMN adhered to the biomaterial surfaces under venous flow conditions compared to the arterial. Shear intensity did not influence the running order of biomaterials with respect to cell numbers. This response in descending order at the end of the experiments was as follows: PU, PVC-DEHD, PP, PE and ePTFE. The biochemical analyses indicate that in the system used only a weak effect on LTB4 release induced by the different materials could be determined. A significant effect caused by flow conditions was not observed. Further experiments, both static as well as dynamic, must be performed for multiple, relevant parameters of haemocompatibility, for potential biomaterials as well as those currently in use in vascular prostheses.