铁路道岔密贴检查器的检修测试方法

密贴检查器是用来检查道岔尖轨或心轨位置状态的设备，也具有挤岔时切断表示的功能。目前主要用于通过列车速度在200m／h以上多点牵引的道岔，在两牵引点检查5mm。本方法适用于各铁路电务段人厂检测及日常维修检测，人厂及维修作业后，都应该经过多次的转换试验来验证密贴检查器的状态及与道岔的准确配合。     

国际

正密其公司为模内贴标提供新的解决方案模内贴标近几年来在塑料包装领域有了较多的应用,以其保护性、功能性和装饰性三位一体的功能,日益为众多包装企业所青睐。英国密其国际公司新近推出的静电发生系统,为这一新工艺提供了有效的解决方案。在模内贴标工艺中,标签必需在模具内精准定位并保持。如采用吸盘或凹版将十分复杂和不可靠,而标签的移动又会导致废品。密其公司的993R静电发生棒和994-SSP单头静电发生系统,利用静电原理将标签准     

ZYJ-7液压转辙机常见故障分析与处理

铁路信号系统是铁路安全运行的重要保证,ZYJ-7液压转辙机是应用于铁路提速、高速区段的道岔转换驱动设备,其主要依靠电机驱动、液压传动来推动道岔的移动转换。ZYJ-7液压转辙机在工作中具有驱动力大、性能稳定等特点,ZYJ-7液压转辙机在工作中能够有效地克服道岔尖轨在密贴时的转换阻力实现道岔的高效、可靠闭合,保障列车的安全运行。本文在分析ZYJ-7液压转辙机工作特点的基础上对ZYJ-7液压转辙机常见故障进行分析并就如何做好ZYJ-7液压转辙机常见故障的处理进行了分析阐述。     

基于磁致伸缩导波的尖轨缺陷检测技术研究

尖轨在其周期性载荷作用下易发生断裂,引发列车事故。为对尖轨缺陷进行检测,文章基于磁致伸缩效应研制了导波检测系统,研究导波在尖轨中的传播特性、导波对尖轨附属件的检测能力以及缺陷的识别能力。采用ABAQUS/Explicit有限元方法研究了不同频率导波在尖轨中的传播特性。所研发的磁致伸缩导波检测系统在尖轨上的检测是可行有效的。使用导波检测系统在尖轨底面激励的水平剪切导波在基本轨和尖轨上可传播的有效距离至少为12 m,在空轨中至少能传播16 m。而且低频导波主要沿轨底传播,高频导波主要沿轨腰和轨头传播,多频导波结合能更加准确地对尖轨的检(监)测。     

一种矿井提升容器的深度测量方法

设计了一种基于编码电缆/旋转编码器多传感器组合测量的位移监测系统,用于测量深井中矿井提升容器的深度。该系统中编码电缆分段铺设在矿井中段附近,相邻的两段编码电缆之间用多芯电缆连接,通过编码电缆实现提升容器爬行停车时的位置高精度检测;测量过程中编码器全程测量,并且与编码电缆的数据进行相互参照。介绍了硬件及软件系统的设计,实验结果表明:该位移监测系统能够保证提升容器在爬行停车时的位移检测误差在6 mm以内,提高了提升容器运行时的可靠性和安全性,为实现超深矿井开采创造了良好的条件。     

框架-密肋复合墙结构剪力分担率计算方法研究

密肋复合墙体具有独特的结构构造形式,其刚度可按不同抗震设防要求进行调整,并可满足复杂建筑形式的要求。该文以框架-剪力墙结构为依据,对框架-密肋复合墙结构协同工作机制及剪力分担率计算方法进行较为系统的研究。基于Timoshenko梁基本理论,将框架-密肋复合墙结构视为由剪切型悬臂框架、弯剪型悬臂梁组成的双重抗侧力体系,采用连续化方法建立框架-密肋复合墙结构的位移微分方程,推导出了计入复合墙剪切变形的水平位移解析表达式和内力计算公式。根据前期试验获得的墙体模型低周反复荷载试验数据,拟合得出密肋复合墙体指数式刚度退化模型,量化了墙体在各变形阶段的刚度退化系数。在此基础上提出不同变形阶段框架-密肋复合墙结构剪力分担率的实用计算方法,并通过算例验证了复合墙刚度退化对结构内力分配的影响程度。     

可变磁路式永磁悬浮系统刚度特性分析及变刚度控制

针对可变磁路式永磁悬浮系统的悬浮力非线性变化的特点,分析系统的刚度特性,提出变刚度控制方法减小系统对外扰作用的敏感度。基于系统力学模型分析了系统结构和控制参数对悬浮刚度的影响,提出了基于悬浮物位移的变刚度控制方法;根据预设的载荷能力和位移变化量,设计参数的变化范围,使系统刚度按设定控制规律发生变化;进行了系统起浮稳定性与系统对外扰敏感度的仿真与实验分析,并与传统PID控制方法进行对比,仿真与实验结果表明:变刚度控制方法能够保证系统稳定起浮,并使外载荷作用时悬浮物的位移变化量减小50%,极大降低了系统对外扰的敏感度,相对于传统PID控制方法其控制特性有较大幅度提高。     

叉车液压系统产生爬行现象的原因分析与故障排除

爬行现象,是液压系统中常见的故障现象。文中从一部叉车由于更换顶升油缸时定位不准引起叉车起升作业时产生"跳动"现象的案例说起,对液压系统产生爬行现象的原因进行分析,系统性总结了爬行故障的预防措施,并顺利排除了该叉车的爬行故障。     

最新小型紧凑模内贴标静电发生器面市

正英国密其国际公司于今年纽伦堡包装工业博览会(Fach Pack,9月27日至29日),以及杜塞尔多夫国际塑料及橡胶展(K Trade Fair,10月19至26日)期间,为模内贴标市场推出最新小型紧凑静电发生器994CG。据密其公司技术总监David Rogers介绍,模内贴标市场将在未来几年中迅速增长,进一步降低标签印制成本。用户反馈信息表明,24V直流电源正在成为业内喜好的机械生产线辅助设备电压选择。密其开     

密肋复合墙-剪力墙混合结构水平位移计算方法研究

密肋复合墙-剪力墙混合结构是把密肋复合墙与剪力墙组合起来,形成的一种新型联合抗侧力结构,有效解决了密肋结构在7度及以上地震烈度区建造高度、应用范围受限的问题。本文对水平荷载作用下复合墙-剪力墙结构的位移计算方法进行研究：依据Timoshenko梁基本理论,将密肋复合墙视为弯剪型悬臂墙,同时考虑其弯曲变形和剪切变形,采用变形连续化方法建立了结构体系的位移微分方程,以常见倒三角形荷载为例推导了密肋复合墙弯曲变形、剪切变形和结构总水平位移的解析表达式。算例分析表明：复合墙-剪力墙结构与框剪结构的刚度特征值、位移公式完全相容,后者可视为前者在复合墙抗弯刚度取无穷大时的一种特殊表现形式;结构侧移曲线呈现弯曲变形为主的弯剪型特征,但复合墙的剪切变形在总变形中占有一定比重,不应忽略。研究工作为复合墙-剪力墙结构的内力计算和抗震设计提供了基础。     

凝固科学技术与材料

从凝固科学与实践发展的角度介绍了当前凝固材料体系的基本框架和凝固科学主要发展阶段的基本理论。作为材料科学与工程的基本组成，凝固科学技术正在现代科学理论的基础上针对传统材料的改性提高和新材料的发展需求，以控形、控构、控性为目标开展优质铸件的定向、晶体生长、快凝、深过冷及各种新型和超常领域凝固过程的研究，并介绍了其中某些方面和展望了可能的发展趋势。     

Development and challenges of planning and scheduling for petroleum and petrochemical production

Production planning and scheduling are becoming the core of production management, which support the decision of a petrochemical company. The optimization of production planning and scheduling is attempted by every refinery because it gains additional profit and stabilizes the daily production. The optimization problem considered in industry and academic research is of different levels of realism and complexity, thus increasing the gap. Operation research with mathematical programming is a conventional approach used to address the planning and scheduling problem. Additionally, modeling the processes, objectives, and constraints and developing the optimization algorithms are significant for industry and research. This paper introduces the perspective of production planning and scheduling from the development viewpoint.     

江澳两地高校文创设计的协同研究与商业实践

目的 探索江门世遗文化的传承、发展和转化的新思路,践行国家在《粤港澳大湾区发展规划》纲要中要求江门承担与港澳地区文化创意合作与开发任务的分工。方法 与澳门高校紧密合作,开展专业培训课程,以开平碉楼为例,从人文视角开展设计研究,梳理开平碉楼的文化脉络,把世遗文化的元素和其背后的文化融入文创产品中,提升文创产品的附加值,推动当地文创产业结构的变革。结果 两地高校构建了稳定的科研团队,开设长期有效的设计培训课程,与景区建立了研究协作关系,帮助景区构建了一套产销研的商业模式。结论 以跨区域高校合作为平台,以文创产品为抓手,依托江澳两地的资源优势,可以构建江门世遗文化全新的品牌形象,最终推动开平世遗文化的活化。     

Error and uncertainty in modeling and simulation

This article develops a general framework for identifying error and uncertainty in computational simulations that deal with the numerical solution of a set of partial differential equations (PDEs). A comprehensive, new view of the general phases of modeling and simulation is proposed, consisting of the following phases: conceptual modeling of the physical system, mathematical modeling of the conceptual model, discretization and algorithm selection for the mathematical model, computer programming of the discrete model, numerical solution of the computer program model, and representation of the numerical solution. Our view incorporates the modeling and simulation phases that are recognized in the systems engineering and operations research communities, but it adds phases that are specific to the numerical solution of PDEs. In each of these phases, general sources of uncertainty, both aleatory and epistemic, and error are identified. Our general framework is applicable to any numerical discretization procedure for solving ODEs or PDEs. To demonstrate this framework, we describe a system-level example: the flight of an unguided, rocket-boosted, aircraft-launched missile. This example is discussed in detail at each of the six phases of modeling and simulation. Two alternative models of the flight dynamics are considered, along with aleatory uncertainty of the initial mass of the missile and epistemic uncertainty in the thrust of the rocket motor. We also investigate the interaction of modeling uncertainties and numerical integration error in the solution of the ordinary differential equations for the flight dynamics.     

Density and viscosity of tetralin and trans-decalin

New measurements are reported for the density and viscosity of tetralin and trans-decalin. The density was determined from room temperature to 60°C for tetralin and to 95°C for trans-decalin. The kinematic viscosity was measured up to temperatures slightly above 100°C. Our results improve upon the values recommended by the American Petroleum Institute for these liquids.     

Creation and motion of dislocations and fracture in metal and silicon crystals

By making a step on one surface ( ) of a rectangular small paralellepiped copper crystal, dislocations could be created by the molecular dynamic method. The dislocation created was not a complete edge dislocation but a pair of Heidenreich-Shockley partial dislocations. Each time a dislocation was created, the stress on the surface was released. Small copper crystals having a notch were pulled (until fracture), compressed and buckled by use of the molecular dynamic method. An embedded atom potential was used to represent the interaction between atoms. Dislocations were created near the tip of the notch. A very sharp yield stress was observed. The results of high speed deformations of pure silicon small crystals using the molecular dynamics are presented. The results suggest that plastic deformation may be possible for the silicon with a high speed deformation even at room temperature. Another small size single crystal, the same size and the same surfaces, was compressed using molecular dynamic method. The surfaces are {110}, {112} and {111}. The compressed direction was [111]. It was found that silicon crystals are possible to be compressed with a high speed deformation. This may suggest that silicon may be plastically deformed with high speed deformation.     

SMC／BMC的回收与再利用

SMC／BMC废弃物对工业及环境造成了很大影响，指出了SMC／BMC回收再利用的紧迫性。通过对目前国际上SMC／BMC回收再利用的3种典型途径优缺点的对比，参照国外SMC／BMC回收再利用的先进方法，对我国SMC／BMC回收再利用提供了可行的建议．     

The Candela and Photometric and Radiometric Measurements

The national measurement system for photometric and radiometric quantities is presently based upon techniques that make these quantities traceable to a high-accuracy cryogenic radiometer. The redefinition of the candela in 1979 provided the opportunity for national measurement laboratories to base their photometric measurements on optical detector technology rather than on the emission from high-temperature blackbody optical sources. The ensuing technical developments of the past 20 years, including the significant improvements in cryogenic radiometer performance, have provided the opportunity to place the fundamental maintenance of photometric quantities upon absolute detector based technology as was allowed by the 1979 redefinition. Additionally, the development of improved photodetectors has had a significant impact on the methodology in most of the radiometric measurement areas. This paper will review the status of the NIST implementation of the technical changes mandated by the 1979 redefinition of the candela and its effect upon the maintenance and dissemination of optical radiation measurements.