嵌入式系统中程序的优化策略

嵌入式系统中的程序往往是运行在有限的硬件资源环境中,而且大多具有实时性的要求,因此要对程序进行优化,尽量提高程序的执行效率,减少程序的存储空间。讨论对嵌入式系统中的程序进行优化的方法和策略。     

可编程序控制器在93#装置仪表联锁上的应用

本文介绍了可编程序控制器与工控机在93#仪表联锁的应用,概述了系统的基本组成,介绍可编程序控制器的程序设计和工控机组态软件应用的几个典型问题。     

论程序文件的编制方法及其内容与要求

本文从“程序”的定义,阐述质量体系、程序文件和质量活动的相互关系,提出程序文件的系统设计方法,通过对质量体系的系统分解与组合,确定了程序文件的基本内容与要求,为编制程序文件的规范化开创了有效途径。     

21000m~3/h空分设备分子筛纯化系统故障分析及处理

分子筛吸附净化流程空分设备中,分子筛纯化系统的运行工况制约了整个空分系统的安全稳定运行。针对分子筛纯化系统经常出现的切换阀机械故障、阀门动作导致的程序问题以及分子筛纯化系统程序联锁控制等问题,详细介绍了故障原因判断和处理措施。     

冰蓄冷系统制冰工况下蒸发器的仿真模拟

建立了冰蓄冷系统制冷机组蒸发器的稳态分布参数模型,并拟合了制冷剂(R22)和载冷剂(质量分数25%的乙烯乙二醇)在制冰工况下的参数计算公式,编制了蒸发器的仿真程序。此仿真程序对于冰蓄冷系统蒸发器的优化设计以及系统能效比的提高、降低冰蓄冷空调系统能耗具有一定的指导意义。     

电网调度系统中的客户／服务器通信程序设计

分析了电网调度系统中客户／服务器通信程序的特点,介绍了应用Delphi开发服务器程序和Visualc＋＋开发客户机程序的方法,并给出了具体的开发实例。     

Unix系统中的汇编语言的使用方法

本文介绍了在 unix 操作系统中如何编写汇编语言程序,讨论了汇编语言与系统调用,汇编语言程序和 C 语言程序之间的相互关系。     

掠入射光学系统成像质量评价

为了能够全面评价掠入射光学系统的成像质量,基于像差理论和傅里叶光学原理,使用Matlab 编程语言编写了针对掠入射系统的像质评价程序,并利用此程序结合ZEMAX 软件对用于太阳观测的Wolter I 型和双曲面-双曲面(H-H)型掠入射系统的成像质量做了详细的分析.结果表明,该像质评价程序能够计算不同口径和焦距的掠入射系统在不同视场,不同工作波长时的点扩散函数、能量集中度、线扩散函数和调制传递函数,对掠入射系统的设计和优化具有指导作用.     

LIMS环境下如何构建电子类自动校准系统

自动校准系统是指在程序特定运行环境中,由标准器、被校准仪器在计算机指令控制下,完成校准过程,获得、保存(或含处理)校准结果的程序。本文以MT8801无线通讯分析仪为例,阐述了在LIMS环境下基于Labview编程构建自动校准系统框架,最终实现校准系统与实验室信息管理系统(LIMS)的自动连接的过程,对LIMS未来在自动校准系统中的运用进行了展望。     

可用于导电样品的程序升温仪

本文叙述了高精度程序升温仪的原理和特性。结果表明此仪器非常适合做超高真空系统内导电样品的程序升温热脱附和程序升温表面反应等研究工作。     

Gefügemäßige Bewertung der Schweißeignung von Stahlgusssorten unter Berücksichtigung der Kaltrissbeständigkeit

Microstructural evaluation of weldability of cast steels considering the sensitivity to cold cracking The behaviour of different types of cast steel at welding of structures is widely determined by the specialities of the microstructure in the heat affected zone (HAZ). The identification of the different areas of microstructure depends on the alloying system of the cast material. At the evaluation of the weldability of cast steels with high or low carbon contents high attention should be drawn to the sensitivity to cold cracking, which correlates with the chemical composition as well as with the inhomogenieties of the initial microstructure.     

Specific Features of the Behavior of Ceramics Based on ZrO2 with an Admixture of 9 Mole% CeO2 in the Process of Deformation

For zirconia ceramics stabilized with 9 mol.% CeO ₂, we study specific features of the processes of deformation and formation of the zones of transformation of the tetragonal phase into the monoclinic phase under the action of mechanical stresses. It is shown that, at room temperature, this transition occurs explosively (autocatalytically) and is accompanied by the formation of large zones of the -phase in the form of strips on the surface of tension of the specimen and the appearance of a nonlinear sawtooth section in the stress–strain diagram. As the testing temperature increases, the degree of autocatalyticity decreases together with the degree of nonlinearity and the diagrams lose their sawtooth character. At the same time, the strength of the material becomes almost four times higher at ~ 200°C and then decreases to the initial level at 400°C. It is assumed that this Type of mechanical behavior can be explained by changes in the mechanisms of hardening of ceramics.     

Formation of the reaction zone between tin‐copper brazing fillers and aluminum‐silicon‐magnesium alloys: Experiments and thermodynamic analysis

A primary challenge in brazing is the controlled formation of phases resulting from interactions of elements of the liquid filler metal with those of the base material. The morphology of the brazed joint, which is decisive for the mechanical properties of the joint, is influenced by present elements and process parameters such as brazing temperature and time. Furthermore, the wetting of the base material is a crucial factor in joining of aluminum because of the low wettability of the alumina layer by molten brazing filler metals. In order to remove the alumina and prevent reoxidation of the substrate surface, the brazing process can be conducted in vacuum or inert gas atmosphere. Again, selection of process parameters is crucial for the quality of the brazed seam. In this work, we focus on the influence of the process parameters on the wetting behavior and the formation of aluminum‐copper phases theoretically by means of thermodynamic calculations using a CALPHAD database as well as by means of in‐situ observations in the large‐chamber scanning electron microscope (LC‐SEM) and by brazing experiments. Both the critical temperatures with respect to the wetting and the reaction kinetics as well as the crucial stages of the brazing process and the resulting phases were determined.     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

力、热载荷作用下纤维在复合材料中的界面应力传递行为

采用三维光弹性实验应力分析和有限元计算两种方法,在拉拔载荷和热残余应力联合作用下,对单丝拔出树脂基复合材料三维冻结切片界面剪应力进行了研究。实验结果和计算表明,在单纤维与基体界面的埋入端及埋入末端附近出现界面残余剪应力的极值;力、热载荷作用下纤维界面剪应力呈抛物线分布,单丝埋入端附近是应力的主要传递区域,最先达到危险应力,出现界面脱胶破坏,然后剪应力沿纤维埋入长度由纤维埋入端附近向埋入末端逐渐传递;界面热残余应力对界面剪应力的影响是使纤维埋入末端应力集中程度降低,使界面剪应力最大值增大。      

Effects of synthetic oil in a compression refrigeration system using R410A. Part II: quality of heat transfer and pressure losses within the heat exchangers

The consequences of the oil rejected by the compressor of a vapour-compression refrigeration system on the operation of the evaporator and condenser are analysed. The modelled prototype uses the mixture of HFC R410A and a synthetic polyolester (POE) oil. The rise of the amount of lubricant circulating in the system leads to a progressive change in the behaviour of the mixture of refrigerant and oil that, for the higher oil mass fraction, evolves like a zeotropic mixture. One also observes that the presence of lubricant is generally associated with a fall of the performances of the heat exchangers, except however in the evaporator where an optimum is observed when the quantity of oil is equal to 0.1% of the total mass of the mixture. Some conclusions are drawn about the choice of correlations for the calculation of the refrigerant side heat transfer coefficient in a plate evaporator.     

空心微珠填充聚氨酯泡沫塑料的力学性能

对不同密度和不同填充质量比的空心玻璃微珠填充聚氨酯泡沫塑料进行拉、压实验,研究了微珠对复合泡沫塑料力学性能的影响。实验结果表明:复合泡沫塑料拉伸曲线特征与普通泡沫塑料类似,但具有不同于普通泡沫塑料的压缩应力-应变特性;材料密度越大,微珠对胞体壁的增强效果越好;微珠团聚和界面粘结不良将可能导致材料力学性能的下降。根据有限元模拟结果和试件破坏形貌的观察探讨了材料的变形和破坏机制。      

Development of Catalytic Converters Using Detonation Spraying

One of the trends in hydrogen power engineering is the development of devices for the preparation of synthesis gas by the catalytic reforming of a hydrocarbon feedstock. Studies show the advantages of catalytic converters based on a modular catalyst support with a honeycomb-type structure produced from a metal foil, both sides of which are coated with highly porous oxide ceramics. The drawback of this design is a poor ability of the coating to withstand high-temperature operating conditions. The coating may detach from the substrate because of the difference in thermal expansion coefficients between the metal foil and the ceramic coating. Besides, a corrosion of metal foil takes place. The result of the present study is the development and application of a two-step coating method, which allows significantly increasing the service life of the catalyst supports. At the first step, a low-porosity ceramic layer is deposited on a metal foil by detonation spraying. At the second step, a high-porosity layer of a ceramic catalyst is deposited from suspension. In this work, the peculiarities of the detonation spraying of the ceramic coating on a metal foil and the design of the obtained catalytic converter have been addressed.     

Investigations into the improvement of the weather protection of unburnt brick masonry,part 1

In June 2006, the Chair of Structural Design at the Technical University of Dresden was commissioned by the Iranian cultural authority ICHHTO and the UNESCO to perform structural design services for the earthquake‐resistant repair and rebuilding of the Sistani House in the historic citadel Arg‐e‐Bam in the south of Iran. The citadel was until its almost complete destruction by an earthquake on 26 Dezember 2003 the largest building of unburnt brick masonry in the world and is listed as a World heritage Site by UNESCO because of its cultural and historical significance. Surveying and documentation work, archaeological rubble clearance and the rebuilding of the Sistani House after its destruction by the earthquake have taken the team from the department to Bam at regular intervals since 2006. In the course of the work, it became apparent that research was needed in the field of the repair of earthquake‐damaged unburnt brick masonry and into the improvement of the shear strength/earthquake resistance and the weather protection of unburnt brick masonry. The article is subdivided in Part 1, Introduction, test performance and assessment of results for additives to loam render as well as Part 2, Assessment of the results for surface treatment to unburnt bricks and the climatic chamber tests.