建筑漏电火灾报警系统安装与调试分析

文章结合漏电火灾报警系统系统的组成与功能,简单介绍了漏电火灾报警系统与火灾自动报警系统的区别,突出了漏电火灾报警系统系统的优势,着重分析了该系统在现场施工中时的安装工艺的注意事项,重视系统的调试运行。     

抽油机井系统效率分析及提升的可行性做法

本文探讨了抽油机系统效率的定义并对其进行相关分析影响系统运行及系统效率的主要因素,提出了系统效率提升的可行性做法,提升了抽油机的系统效率。     

采暖散热器散热量测定系统研究

采暖散热器散热量测定系统是散热器产品热工性能测定与指标评价的标准计量测试系统。本文介绍了按照国际标准和国家标准设计和建造的一个全自动化采暖散热器散热量测定系统。文中分析了有关散热量测定的技术原理和系统组成,提出了改善系统性能和提高系统测量精度的设计方法和特点,提出了缩短系统测定时间、加速稳态过程及数据处理的新思路。系统使用微机实现了多通道测控和分析处理自动化。     

分队计量系统在采油厂的建设与应用

叙述了现河采油厂分队计量系统的建设背景,分析了系统建设过程中各类策略选择的依据,介绍了系统运行流程、系统运行保障措旖、系统实现的功能和实际应用效果,总结了系统建设和实施过程中的认识和体会,并提出了下一步的工作打算。     

电力系统接地技术的特点与应用探讨

阐述了电力供配电系统的工作接地,保护接地和防雷接地三种接地方式的特点及作用,重点分析了保护接地TN系统（TN-C系统、TN-S系统和TN—C—S系统）、TT系统和IT系统的原理及优缺点。明确了接地电阻的要求,得出了正确选择和安装接地方式的重要性。     

VVT-i系统与涡轮增压系统浅析

本文主要介绍了VVT-i系统与涡轮增压系统发展的背景,分析了VVT-i系统与涡轮增压系统的工作原理,说明了VVT-i系统与涡轮增压系统的运用意义,以供参考。     

基于ADUC836单片机的胶带性能检测系统的设计

本文介绍了基于ADUC836单片机的胶带性能检测系统的设计方案,阐述了系统软硬件设计和软件设计.该系统采用ABUC836单片机,使系统性能更加完善.设计结果表明本系统与现有的系统相比,测量精度也提高了100倍,使胶带性能检测系统更加智能化.     

面向对象的智能级进模工步排样系统实现

阐述了面向对象的智能级进模系统(IPDSLS)的实现,给出了系统的运行流程和总体框架,明确了系统的模块划分及相关任务,根据软件工程的系统构造理论,选择面向对象技术创建了系统的OOA模型,从而明确了问题域及系统责任.通过对典型冲压件实例,介绍了IPDSLS系统的运行及结果情况,进一步验证了理论技术的可行性和先进性.     

PDP11仿真系统实时性的研究与评测

本文首先介绍了基于通用Linux系统、为石油测井系统开发的一个PDP11仿真系统,但是该仿真系统无法满足实时性要求.接着对测井系统实时性需求进行了分析,并以RT Linux为基础对整个仿真系统的体系结构进行重新设计.最后,介绍了仿真系统的测试环境,以及对新仿真系统实时性的评测结果.)     

新混沌系统分析及其同步控制

提出了一个新混沌系统,通过Matlab对该系统进行了分岔图、Lyapunov指数、相图等仿真分析,证实了在选定特定参数下,该系统为混沌系统。随着参数的改变,该系统会出现周期--倍周期--混沌--周期--倍周期--混沌交替现象,具有较复杂的动力学特性及对初值的敏感性,通过Multisim电路仿真证实了该系统的物理可实现性。针对提出的新混沌系统,设计了错位投影同步控制器,从理论上证实了在同步控制器的作用下该系统与Chen混沌系统达到了同步,通过Matlab仿真证实了同步控制器的有效性。最后,在同步控制器作用下实现了新混沌系统和Chen混沌系统的数字加密传输。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

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.     

Synthesis of Alumina-Zirconia Nanocomposites by Solgel Process

Al₂O₃-ZrO₂ nanocomposites were developed starting with the solgel process. Composite alumina-zirconia nanopowders were synthesized from metallorganic precursors (Aluminium secondary butoxide and zirconium Iso propoxide) using the solgel process. The parameters affecting the synthesis—solvent, concentration of precursor, R/H ratio (i.e., dilution of water in solvent)—were varied as also the temperature and pH. BET and TEM were used to measure nanosize. Diffuse reflectance spectroscopy and also qualitative optical absorption led to identical particle size estimate. The variation of process parameters was used to study the effect and interdependence of process parameters. Artificial Neural Networks was used to rigorously analyze the process. Although this led to confirmation of interdependence of parameters, the presence of a single overwhelming solvent variable was also established. Then the optimal process was used to synthesize more nanopowder. To produce bulk nanocomposite the nanopowders were sintered by varying the temperature and time period. The sintered lithoids were probed with a vickers hardness tester to measure elastic modulus, hardness, and fracture toughness. The results showed high elastic modulus, modest hardness, and very high fracture toughness.     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Friction Stir Processing Strategies for Uniform Distribution of Reinforcement in a Surface Composite

Friction stir processing (FSP) is an important technique for preparing surface composites. Fabricating defect-free surface composites with uniform particle distribution by FSP is a challenging task. In this study, silicon carbide particles reinforced AA5083 alloy surface composites was fabricated using different FSP strategies including variation in process parameters, dual-tool processing and tool offset overlapping. Material flow of the processed material with reinforcement particles demonstrated that the distribution of particles was influenced by the stirring action of the probe as well as the extrusion of the plasticized material due to the movement of the tool. Process parameters, particularly rotational speed, showed a dominant influence on the distribution of silicon carbide particles.