带留言功能的中央空调控制器

本文介绍了带留言功能的中央空调控制器的设计过程。该中央空调控制器以PIC16C72A单片机为控制核心，运用数字温度传感器LM92采集环境温度；使用HT1621液晶显示模块将系统工作状态显示在LCD屏上；留言功能采用语音处理器ISD1420，以及音频放大芯片LM4991；系统使用了电源管理器LM2673-ADJ，对AC／DC变换后的电压进行管理。     

电气自动化在中央空调中的应用

随着时代的发展，我国的经济也在不断的发展，各大商场、超市等大型商业场所也都纷纷而起，其对中央空调的需求也越来越大。但是在对中央空调的使用的时候，会经常出现一些问题，中央空调电能消耗非常大，其冷源系统的效率也非常低，其环保的性能也比较缺乏，因此，企业一定要对中央空调的功能进行改造，使其达到理想的效果。本文主要中央空调电力能源消耗量大的主要原因以及对电气自动化在中央空调中的应用进行了分析，希望能够改善中央空调电能消耗大和冷源系统效率低下等问题。     

中央空调制冷机的化学清洗

阐述了中央空调制冷机结垢的类型及其产生的原因和危害，分析了中央空调制冷机的冷媒水系统、冷却水系统的化学清洗技术和操作方法。     

连载17：中央空调主机变频技术

文章主要介绍了中央空调主机变频技术的工作原理、主要特点和优势，提出了中央空调主机变频技术应用时应注意的事项和适用的条件和场合，并提供了实际使用的案例。     

变频技术在中央空调系统节能中的应用

介绍中央空调系统的构成及控制原理,通过对中央空调系统节能现状及节能原理论述,详细分析了变频技术在中央空调系统中主机控制、冷冻水循环系统控制、冷却水循环系统、中央空调末端送风的控制原理,结果表明在中央空调系统中采用变频器控制可以节约能耗至少30%。     

中央空调冷却水系统的应用

冷却水系统作为中央空调系统的一个重要组成部分，它的合理应用对中央空调系统的经济、稳定运行起着重要的推进作用。     

IC卡控制器在中央空调中的应用

本文主要介绍中央空调IC卡控制器的作用原理，它作为末端计量器，安装在中央空调的风机盘管的高、中、低档上，进行风量调节同时计量费用，实现一户一表，按需消费。     

当前组合式空调机组的质量问题和改进建议

组合式空调机组是中央空调的重要组成部分，其质量与工作的状态，直接影响着中央空调的运作效果，本文主要论述了在实际使用中当前组合式空调机组存在的诸如风量与制冷量不匹配、机组的体积过大、风机质量不达标、表冷器后带水等问题，并提出相应的改革与建议。     

海信日立推行全新认证体系

近日，海信日立空调公司通过吸收日本中央空调行业的成熟经验，在青岛举办针对全国安装商的专业培训班，在国内中央空调行业率先推行高标准、系统化的安装商培训认证体系，并提出了以“过程决定质量，细节超越满意”为核心的安装质量观，以此促进国内安装商队伍质量意识和服务水平的提高。     

工厂中央空调自动化控制

中央空调的COP能效性高,整个中央空调系统由微电脑控制,系统根据实际负荷做自动化运行,能够有效节约能源和运行费用。每个区间末端风机盘管可自行调节温度,区间无人时可远程或目动关闭。本文就工厂中央空调自动化控制进行深入的探讨。首先阐述了工厂中央空调自动化控制的特点;其次,介绍了空调系统远程自动化监控;最后,分析了工厂中央空调自动化控制系统主要性能指标及功能。它具有一定的参考价值。     

Reliability block diagram analysis

The fundamental principles and techniques employed in the analysis of complex reliability block diagrams are described, together with a systematic method of translating reliability block diagrams into probability state diagrams. The techniques of simplifying probability state diagrams by combining parallel transitions, combining states and approximating the diagrams are discussed in depth.     

基于MBSE的辅助动力装置进气风门控制需求分析

基于模型的利益相关方需求分析是一种MBSE的需求分析方法。本文以某型辅助动力装置进气风门控制为例,应用该方法进行需求分析。选择基于SysML语言的开发工具Rhapsody建立用例图、活动图、顺序图和状态机图等模型;并结合测控工具LabWindows/CVI开发了一套进气风门控制需求仿真验证系统,保证需求的正确性和完整性。     

用AutoCAD创建《电路》电子教案中电路图的方法

《电路》电子教案中电路图的绘制方法很多，而专业绘图软件AutoCAD2000是绘制电路图最理想的工具，本文较详细地介绍了在AutoCAD2000环境中建立电路图专用工具条件的步骤和利用该工具条绘制电路图的方法。并结合PowerPoint和Word软件介绍了在文档中如何插入图片。     

基于实时UML的雷达软件设计

实时统一建模语言（UML）和面向对象的建模技术代表着雷达软件设计的一个发展方向。文中介绍了使用UML的用例图、状态图、顺序图等进行系统分析、设计、实现和测试，并讨论了如何选择UML工具与实时框架以及实时性分析等问题。     

MEASURING STRUCTURE COMPLEXITY OF UML CLASS DIAGRAMS

To provide system designer a valid measure to evaluate the structure complexity of class diagrams objectively,this letter first proposes a nethod to transform a class diagrams into weighted class dependence graph,then presents a structure complexity measure for class diagrams based on tntropy distance.     

相图--解释金属化层稳定性和薄膜反应的热力学方法

介绍了计算相图的起因与发展 ,综述了利用 Gibbs生成自由能数据绘制简化的三元、四元相图的热力学方法 ,尤其是确定相图中直达连线的思想方法 ,最后给出了利用相图来解释金属化层稳定性和薄膜反应的应用实例。     

Use of multicomponent phase diagrams for predicting phase evolution in solder/conductor systems

Although the complete phase equilibrium is never reached in interconnection applications, the assumption of local equilibrium at the interfaces is generally valid in most systems composed of dissimilar materials. Therefore, the tie lines in ternary (or multicomponent) phase diagrams—together with the relevant stability diagrams and the mass balance requirements—can be used for predicting the phase sequences (i.e. diffusion paths) formed, for example, in solder/conductor joints. Generally, binary phase diagrams alone cannot provide sufficient information on the phase formation in solder/conductor systems because they do not bear any information on the relative stabilities between different binary phases in multicomponent systems. As examples, the formation of intermetallic compounds in several solder/conductor systems with Au- or Cu-metallization was studied with the help of ternary phase diagrams as well as experimentally. The phase diagrams were calculated using thermodynamic methods. The experimental results confirmed that the dependence of formation of intermetallic compounds on temperature and solder composition is clearly represented by the phase diagrams supplemented with the stability diagrams. Editor's Note: All compositions are given in wt.% throughout the paper unless otherwise stated.     

Condensed phase equilibria in the metal-In-P systems

Ternary phase diagrams have proven valuable for understanding the reactions between a metal contact and a compound semiconductor, as well as for choosing thermally stable electrical contacts in thermodynamic equilibrium with the semiconductor. Since InP is important for both optoelectronic and electronic devices, the metal-In-P systems are of particular interest. In this work, new portions of isothermal sections of the (Rh, Ir, Ru, Os)-In-P diagrams are presented. Then, since no compilation of the published metal-In-P phase diagrams is available, the diagrams are reviewed here. The features of these diagrams are discussed in terms of the thermodynamics of the metal-In-P systems, particularly the considerable thermodynamic stability of many of the transition metal phosphides. Finally, some of the phases in thermodynamic equilibrium with InP, particularly PdIn and Ni₂P, are highlighted for their potential for high-temperature contacts to InP.     

VLSI design using Apple MacIntosh

VLSI design has caused a revolution in microminiaturization. The design process requires construction of stick diagrams for the digital circuit to be designed. These diagrams are prepared using different colored layers. The color graphics and the color monitors make the overall system quite expensive. The object of this article is to show how an inexpensive personal computer like the Apple MacIntosh can be used for preparing VLSI stick diagrams. The Apple MacIntosh's capabilities include translation, mirroring, detail work and hatching; which are indispensible in the construction of stick diagrams. The stick diagrams for a few examples such as serial adder, half adder, adder/subtractor and generalized pipeline array cell have been worked out. It is hoped that this paper will aid in making VLSI design easier on less expensive and easily obtainable personal computers.     

Trellis complexity and minimal trellis diagrams of lattices

This paper presents results on trellis complexity and low-complexity trellis diagrams of lattices. We establish constructive upper bounds on the trellis complexity of lattices. These bounds both improve and generalize the similar results of Tarokh and Vardy (see ibid., vol.43, p.1294-1300, 1997). We also construct trellis diagrams with minimum number of paths for some important lattices. Such trellises are called minimal. The constructed trellises, which are novel in many cases, can be employed to efficiently decode the lattices via the Viterbi algorithm. In particular, a general structure for minimal trellis diagrams of D_n lattices is obtained. This structure corresponds to a new code formula for D_n. Moreover, we develop some important duality results which are used in both deriving the upper bounds, and finding the minimal trellises. All the discussions are based on a universal approach to the construction and analysis of trellis diagrams of lattices using their bases