汽车用氙气前照灯电子镇流器的设计

采用PIC16F785单片机进行控制,设计并实现了一种新型的汽车用氙气前照灯镇流器。针对当前汽车用氙气前照灯镇流器产品效率低、可靠性差等方面的不足,采用单芯片控制、平面变压器、软开关和全贴片等技术,大幅度提高产品的可靠性,效率提高了4%。实验结果证明了该设计的可行性和有效性。     

数字控制金卤灯电子镇流器

本文针对模拟控制电子镇流器存在的许多不足之处,提出了数字控制电子镇流器的控制方法,采用PIC16F873系列单片机,实现对金卤灯的启动及其稳态运行过程的控制,实现与灯的不同阶段的负载特性相匹配。介绍其工作原理,电路结构组成,并通过实验验证该方法是可行的。     

荧光灯镇流器谐振环的频域分析与设计

电子镇流器与荧光灯的匹配是一个重要又复杂的问题。要使照明系统工作于最佳状态,镇流器谐振电路的设计至关重要。本文将对电子镇流器谐振电路的设计进行理论分析,给出设计方法,并通过仿真和实验验证其合理性。     

道砟胶固化道床力学特性的离散元分析

为探究道砟胶的使用对有砟轨道道床的影响规律,采用镶嵌式组合颗粒单元构造道砟颗粒,根据相关文献确定道砟胶的黏结模型和刚度模型,利用单轴压缩试验和三点弯曲试验确定道砟胶固化道床的细观力学参数,基于离散元法对道砟胶固化道床开展数值模拟,系统分析道砟胶用量和加胶深度对道砟胶固化道床力学特性的影响。模拟结果表明：随着道砟胶加入量的增大,道床的累积沉降量减小且累积沉降量的振幅减小,道床的刚度逐渐增大且增大趋势逐渐趋于平缓;当道砟胶加入量为48 kg/m3时,道床的累积沉降量最小且刚度最大;随着道砟胶加入深度的增大,道床的累积沉降量减小且累积沉降量的振幅减小,道床的刚度与道砟胶加入深度呈线性关系;道床全部加入道砟胶时道床的沉降量最小且刚度最大。     

Walking on ballast impacts balance

Railroad workers often perform daily work activities on irregular surfaces, specifically on ballast rock. Previous research and injury epidemiology have suggested a relationship between working on irregular surfaces and postural instability. The purpose of this study was to examine the impact of walking on ballast for an extended duration on standing balance. A total of 16 healthy adult males walked on a 7.62 m × 4.57 m (25 ft × 15 ft) walking surface of no ballast (NB) or covered with ballast (B) of an average rock size of about 1 inch for 4 h. Balance was evaluated using dynamic posturography with the NeuroCom^® Equitest System^? prior to experiencing the NB or B surface and again every 30 min during the 4 h of ballast exposure. Dependent variables were the sway velocity and root-mean-square (RMS) sway components in the medial–lateral and anterior–posterior directions. Repeated measures ANOVA revealed statistically significant differences in RMS and sway velocity between ballast surface conditions and across exposure times. Overall, the ballast surface condition induced greater sway in all of the dynamic posturography conditions. Walking on irregular surfaces for extended durations has a deleterious effect on balance compared to walking on a surface without ballast. These findings of changes in balance during ballast exposure suggest that working on an irregular surface may impact postural control.     

Impact of railroad ballast type on frontal plane ankle kinematics during walking

Five healthy male subjects walked on a control surface (level concrete), and two sloped rock surfaces (walking ballast-rock about 1.9 cm across; main line ballast-rock about 3.8 cm across) while their rearfoot motion (defined throughout as ankle inversion/eversion as seen from the frontal plane) was measured to determine if the different walking surfaces caused different ankle kinematics. The ballast was placed in 5m long trays that were tilted 7 degrees in the transverse plane. Rearfoot motion was measured while the subjects walked the length of the respective surfaces wearing work boots. A repeated measures ANOVA and a subsequent multiple comparison test revealed that the rearfoot range of motion was significantly greater walking on the main line ballast than walking on either the walking ballast or the level concrete. Meanwhile, the mean range of rearfoot motion for walking ballast was not significantly different from that resulting from walking on concrete. Variability was more than twice as great walking on main line ballast than walking on level concrete. Rearfoot angular velocities walking on level concrete and walking ballast were not significantly different, but both were significantly less than walking on main line ballast. Results suggested that rearfoot motion could be reduced if railroads placed walking ballast where trainmen have to walk as part of their jobs.     

Optimization of ballast plan in launch jacket load-out

The calculation of ballast plan in load-out operations is generally performed assuming a rigid barge. This assumption may not be reliable since in reality the barge is flexible. Having incorrect ballast plan may lead to overstressing of the loaded-out structure. We present a method of finding a more accurate ballast plan, taking into account the flexibility of the barge. This method makes use of a multi-objective evolutionary algorithm to find the optimum ballast arrangement at every load-out stage. We model the load-out configuration as a beam on elastic foundation, loaded with distributed trapezoidal loading representing the load from the structure. Minimizing deflection and curvature of the beam, as well as maximizing the ballast transfer efficiency between the load-out stages are chosen as the objectives of the algorithm. It is shown that the proposed method is better than the conventional rigid barge method in terms of minimizing the deflection and curvature as well as maximizing the ballast transfer efficiency.     

船舶压载系统仿真软件研究与设计

为了对船舶压载水系统的运行过程进行动态仿真与研究，建立了整个船舶压载水系统的仿真模型。具体地，依据工程流体力学的知识，并利用功率键合图的方式，建立了包括管网和基本元件的仿真模型。借助第三方的COM组件VisualGraph，利用VisualC#开发出压载水系统的动态仿真与监控软件。仿真软件将泵、阀、船舱等元件模块化，通过编辑等操作构建具体拓扑结构。操作员可以在此基础上进行压载舱注水、排水等仿真操作，同时对液位变化、泵阀开启、报警等情况进行监控。     

A 100,000‐cd/m2 capacity‐coupled electrodeless discharge backlight with high efficacy for LC TVs

A capacity‐coupled electrodeless Hg discharge lamp has been developed for LC TV backlightings. By applying sinusoidal voltages which are 180° out of phase with a pair of external electrodes, a luminous uniformity of over 84% is attained in two types of lamps whose lengths are 190 and 390 mm. Luminance, efficacy, and input power to the lamp are 114,000 cd/m², 35 lm/W, and 21.5 W when the 390‐mm lamp is driven at 5 MHz. With a frequency below 1.1 MHz, eight 390‐mm lamps, connected in parallel to one another without external ballast impedance, can be driven by using a single inverter.     

地铁线路扣件刚度对钢轨振动与波磨的影响

为探明整体道床轨道区段波磨发生机理及其对轮轨系统参数的影响规律,建立轮对和整体道床轨道三维有限元模型,分析轮轨共振模态与整体道床钢轨振动特性,探讨钢轨扣件刚度和轮对振动模态对整体道床区段钢轨波磨的影响规律.结果 表明:钢轨扣件刚度主要影响钢轨起跳共振频率,而对钢轨pinned-pinned共振频率影响甚微;较低的扣件刚度将激发钢轨较大的振动,在特定频段上过大的钢轨振动会导致对应波长波磨的加剧,进而加速波磨的发展;钢轨在358 Hz下的横向弯曲变形是地铁整体道床区段线路产生特征波长为40 mm波磨的主要原因,故可采取减振措施抑制轮轨系统在358 Hz处的横向振动响应,从而抑制波磨的产生和发展.     

潜艇应急操纵的建模与仿真

应急模型是潜艇航行训练模拟器中很重要的一部分。该文对潜艇水下潜航状态下会出现的三种紧急状况进行了分析，其中潜艇舱室破损进水是导致潜艇失事的比较严重而常见的情况，文中提出了一种新的潜艇舱室破损进水模型，这种模型考虑了破损位置和面积这些因素。另外，在非常紧急情况下，高压吹除和抛弃压载等措施是挽回潜艇的重要手段，该文也对这两个过程进行了建摸。文章最后对应急过程的几种情况分别进行了仿真分析。结果表明所建立的模型是正确有效的。     

Ubiquitous interaction with positioning and navigation using a novel light sensor-based information transmission system

This paper describes a novel light sensor-based information transmission system for indoor positioning and navigation with particular benefits for mobile and wearable computers. It can seamlessly extend outdoor GPS tracking to the indoor environment. In a novel manner, fluorescent light is used as the medium to transmit information, which is encoded by using a pulse-frequency modulation technique. The user receives the encoded light information through a photo-receiver. The information is passed into the wearable or mobile computer after the data is decoded. This information allows positioning information to be given to indoor mobile and wearable computers. We design an economical transmitter circuit by adding few components to a commercial electronic ballast circuit for fluorescent lamps with price of less than US $10. The propose system can be used in indoor guidance and navigation applications. Exemplary applications are included in the paper, with experimented results detailed.     

Bright e‐skin technology and applications: Simplified gray‐scale e‐paper

Abstract— Bright‐color electronic‐paper technology based on in‐plane electrophoresis is very suitable for application in non‐emissive digital surfaces, such as electronic skins, eco‐skins, and electronic wallpaper for atmosphere creation. Aimed at these applications, simplified electrode geometries, aperiodic cell geometries, and a novel concept for built‐in gray levels have been developed.     

Hollow fibers containing various display elements: A novel structure for electronic paper

Abstract— A novel structure for electronic‐paper displays using hollow fibers has been developed, where the hollow fiber is comprised of an outer transparent polymer tube and inner display elements (rotating balls, electrophoretic dispersion fluid, or cholesteric liquid crystals). The structure composed of thin polymer fibers is capable of realizing paper‐like visibility and flexibility, which are vital properties required for electronic‐paper displays. Hollow fibers containing display elements were produced through an industrial manufacturing process using a conventional melt spinning method for the first time and showed electro‐optical switching when the voltage was applied. The hollow fibers were then woven into fabric sheets. The structure and the production process for electronic paper in this study will be a candidate for a simple method to produce large‐area electronic‐paper displays.     

Understanding the mechanisms of electronic ink operation

Owing to the unique features of electronic ink displays, including the bistability, paper‐like appearance, and sunlight visibility, electronic ink displays have been applied in many Internet of Things (IoT) fields. We reviewed mechanisms that have been proposed to be essential for electro‐optical behavior of electronic ink displays. This review might facilitate beginners to start their research in electronic ink studies.     

Loon Copter: Implementation of a hybrid unmanned aquatic–aerial quadcopter with active buoyancy control

Aquatic–aerial unmanned vehicles recently became the focus of many researchers due to their various possible applications. Achieving a fully operational vehicle that is capable of aerial, water‐surface, and underwater operations is a significant challenge considering the vehicle's air–water–air transition, propulsion system, and stability underwater. We present in this paper an unconventional unmanned hybrid aquatic–aerial quadcopter with active buoyancy control that is capable of aerial flight and water‐surface operation, as well as subaquatic diving. We report on the first successful prototype of the vehicle, named the Loon Copter, to provide initial evaluation results of its performance in both mediums. The Loon Copter uses a single set of motors and propellers for both air and underwater maneuvering. It utilizes a ballast system to control vehicle buoyancy and depth underwater, as well as to perform seamless air‐to‐water and water‐to‐air transitions. A closed loop control algorithm is utilized for the vehicle's aerial and water‐surface stability and maneuver, whereas an open loop control algorithm is used for underwater maneuver. The experimental results show a fully operational prototype with six degrees of freedom underwater, stable flight, operation capabilities on water surface, and agile maneuvering underwater.     

Surface treatment,reflectance, and age effects on electronic‐paper reading performance

Abstract— This study is intended to explore the legibility and visual fatigue of different age users under various surface treatments and reflectance of electronic paper. Through the method of character‐search task, the results indicated that compared with single types of treatment [anti‐reflection (AR) 0.8%, anti‐glare, 43% haze), the compound treatment of anti‐reflection and anti‐glare (ARC) exhibited the same legibility, and it showed superior properties to effectively reduce visual fatigue. Hence, it is suggested that electronic‐paper manufacturers should choose the compound surface treatment for better visual performance. On the other hand, the findings also validated that enhancing the reflectance of electronic paper to the same level as regular paper (about 80%) is worthy to be practically implemented. Based on the results of this study, electronic‐paper manufacturers can take useful information to fulfill ergonomic requirements on product design.     

Color displays and flexible displays using quick‐response liquid‐powder technology for electronic paper

Abstract— Color displays and flexible displays that use electronic liquid powder have been developed. Novel types of color displays using either a colored powder or a color filter are discussed. We have also developed a flexible display with low‐cost substrate films with a high‐throughput roll‐to‐roll manufacturing method. These technologies enable a QR‐LPD to be widely used as an electronic‐paper display.     

Modelling the sensitivity to various factors of shipborne pollutant discharges

Most of the marine pollution attributable to ship actions is associated with the illicit discharge of oily residues or ballast water, in what is commonly termed operational pollution. In the particular case of ballast water, careless disposal can lead to severe ecological damage, including the irreversible establishment of communities of invasive species. In its 2004 Convention on ballast water management, the International Maritime Organisation defined the measures to be followed to prevent these environmental issues, including the exchange with mid-oceanic water at a minimum distance from the shore. This paper uses two numerical models to analyse the effects of several factors on the dilution of a discharge from a ship moving in the Spanish Mediterranean waters, in order to determine under which conditions the environmental impact of the discharge will be minimum. The results highlight the dual role played by a freshwater plume, which may contribute either to decrease or to enhance the onshoreward transport of the discharged substance, and the relevance of the ship's speed in determining the dilution rates.     

Dynamic behaviour of railway tracks on transitions zones

Transition zones between structures as bridges or box culverts frequently present higher degradation rates compared to the remaining railway. This paper presents a numerical model for the dynamic loads on the ballast caused by trains passing a transition. The model was validated with field data obtained from an extensive field survey conducted in two transition zones in the Netherlands. Results show that the forces on the ballast vary significantly both in time and space on a transition, especially with the appearance of voids under the sleepers. Implications of the results on the long-term behaviour of transition zones are presented.