存储管理技术中分区法的模拟

介绍了存储管理技术中的固定分区法和可变分区法 ,并给出了基于C语言的程序流程。     

模糊综合评判与输入/输出作图法在模拟电路故障诊断上的应用

输入/输出作图法能根据模拟电路的输入和输出电压的关系对电路进行故障检测。模糊综合评判法可以根据模拟电路中元器件工作寿命、故障率等不同的特性,对电路中故障进行定位。提出将两种方法结合起来用于模拟电路的故障诊断的方法,并在自动频率控制电路进行了举例验证,证明该方法简单可靠。     

Zoning of part of the territory of the eastern Chernobyl radioactive trace on the basis of fractal characteristics of the surface density of <Superscript>137</Superscript>Cs contamination

This study is related to research on informative physicochemical indicators for zoning of contaminated territories. The digital field of the radioactive ¹³⁷Cs contamination in the southern branch of the eastern Chernobyl radioactive trace is studied. The use of fractal analysis based on a technique developed earlier by the authors is proposed for zoning this territory. A brief geomorphologic characterization of the surveyed territory is presented and the requirements for an aerial gamma radiation survey, the processing of data, and the calculation of the fractal dimension are described. Special studies are devoted to the sensitivity of fractal dimension values to the use of different data processing methods.     

顺序注射pH梯度分光光度法同时测定药物中维生素C和扑热息痛含量的研究

基于不同pH下维生素C和扑热息痛的光谱差异,将顺序注射pH梯度技术与人工神经网络算法相结合,用于两种药物成分重叠光谱的解析,实现了两种药物成分的同时测定。实验中讨论了顺序注射pH梯度的建立条件,考察了NaOH浓度、NaOH体积、检测流速等反应条件的影响。在选定的实验条件下,维生素C和扑热息痛的测定范围为1.0～10.0mg/L,检出限分别为0.3和0.2mg/L,分析频率为40样/h。将该方法用于维C银翘片中维生素C和扑热息痛的同时测定,分析结果与标示量无显著性差异,加标回收率在92.0%～109.1%之间。     

Sequential Injection Analysis utilizing Amperometric Biosensors as Detectors for the Simultaneous Determination of L- and D-Pipecolic Acid

Abstract

Enantioanalysis of biomedical substances is very important for clinical analysis because the L- and D-enantiomers of the same chiral compound may be markers for different illnesses. A sequential injection analysis (SIA) system using amperometric biosensors as detectors is proposed for the simultaneous determination of L- and D-pipecolic acid (PA). The amperometric biosensors were based on L-amino acid oxidase (L-AAOD) or/and horseradish peroxidase (HRP) for the assay of L-PA and D-amino acid oxidase (D-AAOD) and/or HRP for the assay of D-PA. The linear concentration ranges are of pmol/L to nmol/L magnitude order, with very low limits of detection. The SIA/biosensors system can be used reliably on-line for the simultaneous assay of L- and D-PA from serum samples, with a frequency of 34 samples per hour.     

An exploration of simultaneous engineering for manufacturing enterprises

With the increasing application of high technology in manufacturing enterprises, the traditional serial or sequential production approach has begun to be replaced by a parallel or simultaneous production approach. The functional balance of organisations of current manufacturing enterprises is decline. The organisation within manufacturing enterprises needs to be restructured and the functions need to be adjusted. Many production functions within an enterprise can be integrated by following the production information. This is the premise of this exploration of simultaneous engineering in manufacturing enterprises. A functional model of an enterprise is described in this paper. Some possibilities of functional integration within an enterprise are discussed. Finally, some related research activities are outlined to stimulate an open discussion on the point of view.     

理学SIMULTIX 10/11型多道X射线荧光光谱仪的背景测定装置与应用

文章介绍了理学SIMULTIX 10/11多道同时型X射线荧光光谱仪上所配备的具有背景测定与扣除功能的固定型测角仪的原理、特点和应用实例。该测角仪能明显地提高痕量元素分析的灵敏度与准确度,而且扩大了对于不同类型样品的分析适应范围,例如铁素体与奥氏体样品中钒的测定等。     

Molecular dynamics simulation of multi-groove nano-milling

This article investigates the nano-milling of multi-grooves on single crystalline copper. To explore the material removal mechanisms, molecular dynamics (MD) simulations were carried on both sequential and simultaneous nano-milling processes. It was found that to obtain quality grooves; a simultaneous multi-grooving requires a larger wall thickness between two adjacent grooves. Under sequential nano-millings or a simultaneous nano-milling with same rotational direction of the tools, the minimum wall thickness can be identified by residual stress distribution analysis. Under a simultaneous nano-milling with opposite rotational direction of the tools, this requirement of minimum wall thickness is better identified by strain rate distribution analysis. Overall, the simultaneous nano-milling with opposite rotational direction of the tools gives the best groove quality. A detailed machinability analysis showed that the groove quality by nano-milling can be improved by increasing the depth of cut and wall thickness between two adjacent grooves.     

多轴同步载荷的疲劳强化效能探讨

针对可靠性强化试验的RS(repetitive shock)机全轴随机振动环境3个主要特性之一的多轴同步加载特性开展其疲劳强化机理研究。本文首先归纳了多轴疲劳频域分析方法,然后在此基础上证明了多轴振动激励同步加载比单轴振动激励依次加载更能有效激发疲劳失效,从而揭示RS机全轴随机振动环境多轴同步加载特性的疲劳强化机理。     

大型轴流风机叶片的气动弹性数值分析研究

在叶轮机械的流固耦合中以弹性体流固耦合问题最具难度。在这类问题中,需要考虑叶片在运转过程中的弹性变形与振动对流场的影响以及振荡流场的反作用。以北京地铁18号专用轴流风机为例,在考虑叶片变形和流场之间相互影响的耦合状态下,探讨机叶片气固耦合问题的计算方法。采用CFX软件进行流场计算、ANSYS软件进行结构计算,以MFX- ANSYS/CFX为数据耦合平台,应用弱耦合分区法对风机叶片的气动弹性进行数值模拟分析。并与不考虑叶片弹性变形的情况进行对比,发现考虑气动弹性的最大应力几乎是不考虑气动弹性的最大应力的两倍,相应的安全系数相差较大,不考虑叶片的气动弹性容易高估叶片结构的安全性。分析考虑弹性变形对叶片结构安全性的影响,说明叶片的气动弹性分析的必要性和重要性。     

Laboratory evaluation of dripper performance

The catch can method is traditionally used for evaluating performance of drip systems. Two variations of this method are commonly applied in laboratory testing of drippers: the sequential and the simultaneous method. This study compared uniformity and measurement uncertainty of the two methods, with the overall aim of improving irrigation water management. The simultaneous method was found to have a lower coefficient of variation (C_v) and measurement uncertainty, indicating that it is more accurate than the sequential method. In all the tests, however, the C_v was determined to be <5%, which is acceptable as per the current reference standard.     

多轴载荷对疲劳裂纹的影响

针对振动疲劳试验的载荷加载方式问题,比较分析了传统振动试验台的单轴载荷依次加载和目前的多轴振动台的多轴载荷同时加载对疲劳裂纹应力强度因子的影响,揭示了多轴振动载荷同时加载对疲劳失效具有更高的激发效能。     

顺序多点喷射单一燃料天然气发动机台架试验系统的研制

本文阐述了顺序多点喷射天然气发动机台架试验系统的构成及工作原理，系统可以方便地实时监测天然气发动机的工况参数，并可在线调整优化电控单元的控制参数。台架试验表明，系统性能稳定，工作可靠，有助于天然气发动机的台架试验研究及其电控单元的控制参数的优化。     

基于ZigBee的LED路灯固件远程在线升级研究

为了有效降低嵌入式系统的升级和维护成本,根据嵌入式设备存储结构和更新原理,提出了一种基于ZigBee的固件远程在线升级技术,包括在应用编程(IAP)在线升级、ZigBee协议的改进、片上Flash分区、应答机制、断点续传技术和滑动窗口协议。结合远程在线升级策略在LED路灯节能控制系统中的应用试验,详细阐述了远程固件在线升级流程。研究结果证明,该方案具有快捷简便、硬件成本低、通信误码率低的优点,具有广阔的应用前景。     

基于LabVIEW焊接数据采集分析系统的开发

介绍了虚拟仪器领域中最具有代表性的图形化编程开发平台LabVlEW,并对Labview驱动普通数据采集卡进行了研究.利用实验室已有的焊接信号采集系统及光谱仪,基于LabVIEW软件进行编程,开发出了一套数据采集系统,将采集到的GMAW的电流、电压波形信号及光谱信息进行综合分析,实现了在每个时刻都在LabVlEW的界面上进行同步显示,并且同步显示此刻电压和电流的具体数值,使得对光谱和电信号的研究观察更加直观.     

混合动力汽车能量管理策略的四步骤设计方法

以行星齿轮结构的混合动力汽车的动力系统为研究对象,提出了一套能量管理策略的四步骤设计方法。第一步,引入混杂动态系统理论来描述既有离散事件动态系统特征又有连续变量动态系统特征的混合动力系统;第二步,利用序列二次项规划算法和动态规划算法分别求解出最佳功率分配和最佳工作模式切换序列的基本规律;第三步,建立基于规则和模糊规则的能量管理策略;第四步,利用遗传算法对第三步已经建立的工作模式切换规则和功率分配的模糊控制规则中的参数进行优化,以获得更佳的控制效果。     

A system for acquiring simultaneous electron energy-loss and X-ray spectrum-images

A compositional imaging system based on simultaneous scanning electron energy‐loss spectroscopy (EELS) and energy‐dispersive X‐ray spectroscopy (EDS) was developed. This system utilizes the combined power of EELS and EDS for quantitative compositional imaging at nanometre resolution. The system is particularly suitable for, but not limited to, biological research, as it simultaneously provides sensitive maps of an element such as Ca or P from EELS and of many other elements from EDS. Degradation of resolution by specimen drift is prevented by correcting for drift during data acquisition, using image cross‐correlation. Several advanced features are implemented for real‐time and/or off‐line quantitative analysis, and the performance of the system is illustrated with practical applications to compositional imaging of cardiac muscle.     

Fluid-based Slotting Optimization for Automated Order Picking System with Multiple Dispenser Types

Slotting strategy heavily influences the throughput and operational cost of automated order picking system with multiple dispenser types, which is called the complex automated order picking system (CAOPS). Existing research either focuses on one aspect of the slotting optimization problem or only considers one part of CAOPS, such as the Low-volume Dispensers, to develop corresponding slotting strategies. In order to provide a comprehensive and systemic approach, a fluid-based slotting strategy is proposed in this paper. The configuration of CAOPS is presented with specific reference to its fast-picking and restocking subsystems. Based on extended fluid model, a nonlinear mathematical programming model is developed to determine the optimal volume allotted to each stock keeping unit (SKU) in a certain mode by minimize the restocking cost of that mode. Conclusion from the allocation model is specified for the storage modules of high-volume dispensers and low-volume dispensers. Optimal allocation of storage resources in the fast-picking area of CAOPS is then discussed with the aim of identifying the optimal space of each picking mode. The SKU assignment problem referring to the total restocking cost of CAOPS is analyzed and a greedy heuristic with low time complexity is developed according to the characteristics of CAOPS. Real life application from the tobacco industry is presented in order to exemplify the proposed slotting strategy and assess the effectiveness of the developed methodology. Entry-item-quantity (EIQ) based experiential solutions and proposed-model-based near-optimal solutions are compared. The comparison results show that the proposed strategy generates a savings of over 18% referring to the total restocking cost over one-year period. The strategy proposed in this paper, which can handle the multiple dispenser types, provides a practical quantitative slotting method for CAOPS and can help picking-system-designers make slotting decisions efficiently and effectively.     

A knowledge-based manufacturing and cost evaluation system for product design/re-design

Various research studies have concluded that most new design projects are actually re-design activities. This re-design may be for improvement or for reprovision of existing products. Most research efforts for providing computer tools for supporting conceptual or early design mainly concentrated on the design of new products. In practice manufacturing plans generated when an order was placed may quickly become out-dated as the manufacturing environment and constraints often change. It is therefore equally important to regenerate manufacturing plans and re-evaluate design every time a product is changed, re-designed or reordered. This project focuses on manufacturability analysis and provides re-design support for conceptual design of discrete single-piece mechanical parts with emphasis on machined processes. This limitation of implementing the prototype system for re-design activities is not a system design or methodology restriction. The condition has been imposed by the authors as a prelude to validating the system and its results. A novel hybrid approach using a combination of sequential flowchart logic and an expert system has been developed which uses a user-defined feature tree as the input for its analysis. The system allows the designer to estimate manufacturability according to criteria of time and cost, and also to explore different scenarios of parametric variation in the design. A case study has been presented to validate the system’s practicality and usefulness.     

基于马尔可夫排队论的上高峰阈值策略的研究

电梯随机服务系统中的上高峰时期，进行阈值研究，有利于减少乘客的候梯时间和电梯的的停车次数。阈值是在高峰期的情况下电梯在门厅的停留策略，也即电梯每次服务的最小乘客数。利用马尔可夫排队论来求取阈值，并研究阈值随着乘客到达率增加而变化的规律，在确定好使用分区还是不分区的调度策略之后，再加上阈值策略，在群控系统中会取得很好的调度效果。仿真试验证明了该方法的有效性。