Cotton stalk restitution coefficient determination tests based on the binocular high-speed camera technology

The restitution coefficient(RC)of cotton stalks is an important elementary physical parameter that is required to establish the crushing mechanical model and research the film residue separation machinery.In this study,the calculation method of restitution coefficient considering the rotation motion of stalk-shaped agricultural materials was derived based on the principle of kinematics and the energy restitution coefficient method,and a test bench for measuring the RC was designed and built.The effects of collision material,moisture content,length,diameter,release height,and collision angle respectively on the RC were investigated by single-factor experiments and orthogonal experiments,and the regression models between influence factors and the RC were established.The results showed that Q235 showed the highest value of the RC,and it was followed by cotton stalks and soil lumps,sequentially.The RC of cotton stalks decreased with the increase of moisture content and diameter,while it increased at first and then decreased with the increase of length.As the release height was less than 500 mm,the RC increased with the increased release height.As the collision angle was less than 40°,the RC showed a linear increasing trend.The significance of the effects of factors on RC decreased with the following sequence:collision angle,length,release height,diameter,and moisture content.Length,collision angle,and release height were extremely significant.The contrast test results showed that the values based on Newton’s restitution coefficient method were smaller than that based on the energy restitution coefficient method.The verification test showed that the predicted rebound height of cotton stalks calculated based on the energy restitution coefficient method was closer to the actual rebound height,and the relative error was less than 5%.

KL-SG High-Speed Rail-a catalyst for national economic development Sri Viknesh Permalu and Karthigesu Nagarajoo

Purpose-In an increasingly interconnected world,transportation infrastructure has emerged as a critical determinant of economic growth and global competitiveness.High-speed rail(HSR),characterized by its exceptional speed and efficiency,has garnered widespread attention as a transformative mode of transportation that transcends borders and fosters economic development.The Kuala Lumpur-Singapore(KL-SG)HSR project stands as a prominent exemplar of this paradigm,symbolizing the potential of HSR to serve as a catalyst for national economic advancement.Design/methodologylapproach-This paper is prepared to provide an insight into the benefits and advantages of HSR based on proven case studies and references from global HSRs,including China,Spain,France and Japan.Findings-The findings that have been obtained focus on enhanced connectivity and accessibility,attracting foreign direct investment,revitalizing regional economies,urban development and city regeneration,boosting tourism and cultural exchange,human capital development,regionai integration and environmental and sustainability benefits.Originality/value-The KL-SG HSR,linking Kuala Lumpur and Singapore,epitomizes the potential for HSR to be a transformative agent in the realm of economic development.This project encapsulates the aspirations of two dynamic Southeast Asian economies,united in their pursuit of sustainable growth,enhanced connectivity and global competitiveness.By scrutinizing the KLSG High-Speed Rail through the lens of economic benchmarking,a deeper understanding emerges of how such projects can drive progress in areas such as cross-border trade,tourism,urban development and technological innovation.

Key technologies and applications of intelligent dispatching command for high-speed railway in China

Purpose–The intelligent Central Traffic Control(CTC)system plays a vital role in establishing an intelligent high-speed railway(HSR)system.As the core of HSR transportation command,the intelligent CTC system is a new HSR dispatching command system that integrates the widely used CTC in China with the practical service requirements of intelligent dispatching.This paper aims to propose key technologies and applications for intelligent dispatching command in HSR in China.Design/methodology/approach–This paper first briefly introduces the functions and configuration of the intelligent CTC system.Some new servers,terminals and interfaces are introduced,which are plan adjustment server/terminal,interface for automatic train operation(ATO),interface for Dynamic Monitoring System of Train Control Equipment(DMS),interface for Power Supervisory Control and Data Acquisition(PSCADA),interface for Disaster Monitoring,etc.Findings–The key technologies applied in the intelligent CTC system include automatic adjustment of train operation plans,safety control of train routes and commands,traffic information data platform,integrated simulation of traffic dispatching and ATO function.These technologies have been applied in the Beijing-Zhangjiakou HSR,which commenced operations at the end of 2019.Implementing these key intelligent functions has improved the train dispatching command capacity,ensured the safe operation of intelligent HSR,reduced the labor intensity of dispatching operators and enhanced the intelligence level of China’s dispatching system.Originality/value–This paper provides further challenges and research directions for the intelligent dispatching command of HSR.To achieve the objectives,new measures need to be conducted,including the development of advanced technologies for intelligent dispatching command,coping with new requirements with the development of China’s railway signaling system,the integration of traffic dispatching and train control and the application of AI and data-driven modeling and methods.

Progress in high-speed train technology around the world

This is a review of high-speed train development in the sense of technology advances all over the world. Three generations of high-speed trains are classified according to their technical characteristics and maximum operating speed. Emphasis is given to the newly developed high-speed train in China, CRH380. The theoretical foundations and future development of CRH380 are briefly discussed.

Cooperative communication technology based on relay antenna in high-speed train scenario

The user signal quality as well as the performance of transmission link experiences severe loss due to wireless channel fading and propagation loss in high-speed railway scenario.To improve the quality at the receiving end,spatial diversity was realized by means of cooperative communication technology based on the uncorrelated characteristics of the channels.The model of mobile communication system in high-speed railway was set up,and a cooperative scheme based on statistics was proposed.Mathematical analysis and simulation results show that the quality of the received signal and the performance of the transmission link are significantly improved using cooperative communication technology compared to that in non-cooperative communication mode.

New technologies for high-risk tunnel construction in GuiyangGuangzhou high-speed railway

Based on the construction of high risk tunnels in Guiguang-Guangzhou high-speed railway, several new technologies were developed for high-risk tunnel con- struction. First, an integrated advanced geological predic- tion was developed for tunneling in karst area. Then, a new system of ventilation by involving the dedusting technol- ogy was proposed and used in the field, which received a good air quality. Finally, a method to minimize the dis- tance between the working face and the invert installation was proposed by optimizing the invert installation and adopting the micro bench method. Applying the method to the project obtained an excellent result. The achievement obtained for this study would be able to provide a valuable reference to similar projects in the future.

The Calibration of High-Speed Camera Imaging System for ELMs Observation on EAST Tokamak

A tangential fast visible camera has been set up in EAST tokamak for the study of edge MHD instabilities such as ELM. To determine the 3-D information from CCD images, Tsai＇s two-stage technique was utilized to calibrate the high-speed camera imaging system for ELM study. By applying tiles of the passive stabilizers in the tokamak device as the calibration pattern, transformation parameters for transforming from a 3-D world coordinate system to a 2-D image coordinate system were obtained, including the rotation matrix, the translation vector, the focal length and the lens distortion. The calibration errors were estimated and the results indicate the reliability of the method used for the camera imaging system. Through the calibration, some information about ELM filaments, such as positions and velocities were obtained from images of H-mode CCD videos.

Investigation of condition-induced bubble size and distribution in electroflotation using a high-speed camera

In the flotation process, bubble is a key factor in studying bubble-particle interaction and fine particle flo- tation. Knowledge on size distribution of bubbles in a flotation system is highly important. In this study, bubble distributions in different reagent concentrations, electrolyte concentrations, cathode apertures, and current densities in electroflotation are determined using a high-speed camera. Average bubble sizes under different conditions are calculated using Image-Pro@ Plus （Media Cybernetics@, MD, USA） and SigmaScan@ Pro （Systat Software, CA, USA） software. Results indicate that the average sizes of bubbles, which were generated through 38, 50, 74, 150, 250, 420, and 1000 μm cathode apertures, are 20.2, 29.5, 44.6, 59.2, 68.7, 78.5, and 88.8 μm, respectively. The optimal current density in electroflotation is 20 A/m2. Reagent and electrolyte concentrations, current density, and cathode aperture are important factors in controlling bubble size and nucleation. These factors also contribute to the control of fine- Particle flotation.

Study on 5G Application Scenarios in Intelligent High-Speed Railway

5G technology is indispensable for developing comprehensive perception and ubiquitous interconnection of intelligent high-speed railways(HSRs),and can be applied to many scenarios in intelligent construction,intelligent equipment,intelligent operation and in other fields.In order to promote the standardized application of 5G technology in intelligent HSRs in a scientific and orderly manner and to avoid redundant construction and wasteful investment,it is imperative to carry out a systematical top-level design of the application scenarios at the initial stage.To this end,after investigating and analyzing the 5G application demands in different aspects of HSRs and the general structure of the railway 5G network,this paper formulates an overall planning of 5G technology application scenarios and proposes solutions to some typical application scenarios in the intelligent HSR system,based on the architecture and requirements of the intelligent HSR system.

Visualization of High-Speed Impact of Projectile in Granular Sheet with Destructive Collision of Particles

The impact and penetration of a projectile in a particle-laden space, which are expected to have frequently occurred during the formation of the solar system and will occur in the case of an impact probe for future planetary exploration, were experimentally simulated by using the ballistic range. A two-dimensional sheet made from small glass beads or emery powder was formed by the free-falling device through a long slit in the test chamber evacuated down to about 35 Pa. A polycarbonate projectile of a hemi-sphere-cylinder or sphere shape with the mass and diameter about 4 g and 25 mm, respectively, was launched at the velocity up to 430 m/s, and the phenomena were observed by the high-speed camera at 20,000 fps. From a series of images, the bow-shock-wave-like laterally facing U-shaped pattern over the projectile and the absence of particles in the trail behind it were clearly seen. At the impact of the particles on the projectile surface, fine grains were formed due to the destructive collision and injected outward from the projectile. The images obtained by different lighting methods including the laser light sheet were compared. The effects of the particle diameter, its material and the impact velocity were also investigated.

Visualization of High-Speed Impact of Penetrator into Icy Target

For application to exploration under the surface of icy objects in the solar system, the penetration of an impact probe into an icy target was experimentally simulated by using the ballistic range. Slender projectiles with a cylindrical body and various nose shapes were tested at the impact velocity 130 - 420 m/s. The motion of the penetrator, fragmentation of ice and crater forming were observed by the high-speed camera. It revealed that the crown-shaped ejection was made for a short time after the impact and then the outward normal jet-like stream of ice pieces continued for much longer time. The concave shape of the crater was successfully visualized by pouring the plaster into it. The two-stage structure, the pit and the spall, was clearly confirmed. The rim was not formed around the crater. Observation of the crater surface and the ice around the trace of the penetrator shows that both crushing into smaller ice pieces and recompression into ice blocks are caused by the forward motion of the penetrator. In case of a body with a flow-through duct, ice pieces entering the inlet at the nose tip were ejected from the tail, resulting in relaxation of the impact force. The correlation of the penetration distance and the crater diameter with the impact velocity was investigated.

江西桃红岭保护区同域分布有蹄类动物活动节律差异

为探究同域分布的有蹄类动物活动节律及其季节性差异,2017年3月—2019年5月,利用红外相机技术在江西桃红岭梅花鹿国家级自然保护区对有蹄类动物开展野外监测。在15208个相机有效工作日中,共拍摄到梅花鹿(Cervus nippon)、野猪(Sus scrofa)和小麂(Muntiacus reevesi)3种有蹄类动物,相对丰富度依次为3.90%、9.72%和39.59%。年活动格局分析表明,梅花鹿和野猪在4月相对丰富度最高,小麂在5月和7月相对丰富度最高,三者均在12月相对丰富度最低。核密度估计和重叠系数的分析结果表明:(1)在日活动节律上,梅花鹿属于夜间活动为主、晨昏活动为辅类型,野猪与小麂同属于以晨昏活动为主、昼间活动为辅类型。(2)梅花鹿日活动节律存在明显的季节性变化,春季与夏季的重叠系数最高(Δ=0.83)。野猪与小麂日活动节律无明显的季节性变化。(3)不同物种日活动节律的重叠系数存在差异。野猪与小麂的日活动模式高度重叠,但与梅花鹿的活动高峰基本错开。研究揭示了3种有蹄类动物的活动节律及其季节性差异,为深入开展同域分布有蹄类物种的共存机制奠定了基础。

RIA下PCMI行为的堆外验证试验研究

目前国内的反应性引入事故(RIA)研究中尚未开展芯块包壳机械相互作用(PCMI)失效模式的相关试验研究。为探究有效的试验方法并获取相关试验数据以分析包壳失效的作用机理,本文基于自主设计的堆外模拟PCMI试验的压缩膨胀(EDC)试验装置,采用高速摄像技术辅助,获取了双轴加载燃料元件包壳失效过程中的载荷、应变、破口情况等数据。研究结果表明,试验得出的包壳管残余应变比位于-0.1~0.5之间,符合堆内残余应变比范围。研究结果可为将来开展堆内试验储备技术和积累经验,为安全准则的建立及补充提供可参考的基础数据。

基于次镜像移补偿的折反式航测相机光机系统设计

针对航测相机对地摆扫成像过程中的动态像移问题,采用两镜望远系统的矢量像差理论,将次镜作为像移补偿元件,通过次镜多维运动实现航测相机的综合像移补偿。次镜在对像移进行补偿的过程中会发生偏心和倾斜,导致次镜离轴,影响成像质量,因此,建立了失调折反光学系统成像模型,研究次镜像差场偏移矢量与次镜失调量之间的关系,并分析次镜多维运动对成像质量的影响。为验证次镜多维运动的像移补偿能力,搭建实验平台对该航测相机进行了实验室内以及外场成像试验。结果表明,采用该像移补偿技术的航测相机动态分辨率可达74 lp/mm,且像移补偿精度优于0.5个像素,达到设计预期。

基于样线法及红外相机技术的安徽输电线路鸟类活动规律初步研究

近年来,在输电线路附近活动的鸟类日益增多,由此引发的输电线路故障也常被报道,研究输电线路上鸟类的活动规律对于保障输电线路运行的安全性具有重要意义。为探究输电线路上鸟类的活动规律,本研究采用样线法对安徽输电线路沿线附近鸟类进行了调查,并结合红外相机技术,系统调查和分析了五处高压线路杆塔上鸟类的活动情况。调查结果显示:样线法调查到的输电线路沿线活动鸟类共计18目46科135种,主要以小型鸟居多,迁徙季节有大型侯鸟类。常见鸟类有喜鹊、麻雀、白头鹎、丝光椋鸟、八哥、山斑鸠、珠颈斑鸠等。在输电线路杆塔上做巢的高危鸟类有黑翅鸢、红隼、八哥、灰椋鸟、黑领椋鸟、喜鹊。红外相机拍摄到的鸟类共11种,其中相对丰富度最高的3种鸟类依次是喜鹊、八哥和乌鸫。鸟类的日活动时间段大致在5:00—19:00,活动峰值在7:00—9:00和15:00—17:00时间段,13:00附近出现活动低谷。本研究可为输电线路鸟类安全防护策略和技术方案的制定提供一定的科学依据。

赤水桫椤自然保护区小灵猫及其潜在啮齿类猎物活动节律的季节适应格局

动物的日活动节律具有内源性且受外界生态因素(光周期、气候和食物等)影响,是动物生态适应性特征之一。阐明活动节律与气候和捕食者−猎物的关系,对于理解动物的生存策略、指导保护等至关重要。目前通过红外相机技术探究野生动物日活动节律日益受到学者们的关注。灵猫科动物是热带和亚热带生境中的重要次级消费者之一,但其野外相关研究甚少。本研究基于2016年12月至2022年7月在贵州赤水桫椤国家级自然保护区及其周边区域设置的60个红外相机位点监测影像资料,筛选小灵猫(Viverricula indica)及其相应监测位点的潜在啮齿类猎物数据。通过核密度函数比较分析了保护区内、外的小灵猫及其潜在啮齿类猎物在雨季、旱季的日活动节律特征。结果显示,小灵猫有明显的晨昏两个活动高峰,时间分别是03:00—06:00和19:00—24:00。季节比对发现,小灵猫雨季凌晨活动高峰(03:00—05:00)早于旱季(04:00—06:00),活动强度较旱季高且集中;黄昏后的活动较旱季有所延长。进一步分析其活动与潜在的啮齿类猎物的重叠度,结果发现小灵猫与赤腹松鼠(Callosciurus erythraeus)的重叠度整体较低(雨季,Δ=0.18;旱季,Δ=0.16);与夜行性鼠类的活动节律重叠度高达90%以上,其中旱季的重叠系数(Δ=0.93)高于雨季(Δ=0.90)。此外,在保护区内的小灵猫凌晨活动高峰结束较保护区外延迟约1 h;黄昏后高峰阶段的活动强度(核密度)峰值明显高于保护区外。少许日间活动也主要出现在保护区内。上述结果表明,小灵猫的昼夜节律既有保守性,也具有一定的季节可塑性。这些特征型表现与季节性猎物分布和环境变化关联,并受人类活动的影响。本研究结果对充分认识小灵猫生活史特征以及实现物种有效保护提供数据支持。

后加速内增强技术条纹相机及其非线性强度修正

为实现X射线条纹相机大动态范围性能和精密化诊断,从光子密度探测阈值出发,研究条纹相机后加速内增强技术理论.降低记录系统灵敏度限制的光子密度探测阈值,有利于提高动态范围性能.研制后加速内增强技术条纹相机,组建超快实验标定系统,实验显示相机动态范围达2578∶1.相比具有饱和效应的微通道板内增强技术,该技术扩展了动态范围性能.方向角各不相同的电子入射栅网时,电子的透过率不同,从而导致电子在荧光屏上信号强度的非线性.给出成像区域强度误差分布及其修正方法,相比较未修正的动态范围,误差在7.7%.后加速内增强技术系统结构紧凑,有利于提高条纹相机动态范围,有助于实现中国激光惯性约束核聚变定量测量和精密化诊断目标.

基于红外相机技术的野化梅花鹿活动节律和集群行为研究

为了研究人工饲养梅花鹿在野外适应的情况,2020年5月—2021年7月采用红外相机技术对河南省济源市圈养野化梅花鹿进行了调查。采用公里网格的形式,安放了20台红外相机,共收获3334有效相机日,获取独立照片9669张。成年梅花鹿雌雄比为1.45。共记录到11种集群模式,单只雌体占总数的36.63%,单只雄性占总数的37.41%;多雌集群的比例达到9.07%;幼体单只占比4.92%。在携有幼体的情况中,以单只或多只雌体携幼为主,拍摄到371张独立有效照片,其余2种情况仅拍摄到69张照片。雌体携幼主要发生在夏季,而雄体携幼主要发生在冬季。梅花鹿的日活动节律呈双峰型,分别为06:00—08:00和16:00—18:00。冬季的梅花鹿日活动时间段为08:00—16:00,活动峰值在11:00—13:00。春-夏季的重叠系数最大(Δ=0.9350,P<0.01),其次是春-秋季(Δ=0.9134,P<0.01)、冬-春季(Δ=0.8785,P<0.01)和夏-秋季(Δ=0.8760,P<0.01),重叠系数最小的季节是夏-冬季(Δ=0.8214,P<0.01)。该研究基于无人为干扰的野外圈养条件下的调查记录,研究了野化梅花鹿的活动节律和集群行为,为梅花鹿下一步野外放归提供了技术基础。

同步触发和级联滤波的分幅相机皮秒高压脉冲研究

脉冲展宽分幅相机是脉冲展宽技术与微通道板(microchannel plate,MCP)分幅相机的结合体,其时间分辨率与皮秒高压脉冲呈非线性波动关系.采用同步触发模式和级联结构LC高通滤波器产生皮秒高压脉冲,将其与影响时间分辨率的阴极电压和漂移距离结合,应用于脉冲展宽分幅相机的时间分辨率研究中.结果表明,同步触发式多级Marx电路能产生半高宽优于1 ns的高压脉冲,随着级联LC高通滤波器从1阶增至7阶,产生皮秒高压脉冲的半高宽从558 ps降至409 ps,幅值从-3.6 kV降至-1.4 kV,上升沿斜率的非线性波动为5.03~10.25 V/ps;将其加载于MCP通道内的光电子倍增模型,获得的MCP分幅相机时间分辨率由206 ps提高至149 ps;而将其应用于脉冲展宽分幅相机,随着阴极电压和漂移距离增加,时间分辨率的非线性波动为3.8~39.4 ps.通过数据统计和对比发现,当同步触发Marx电路与3阶LC高通滤波电路相结合时,脉冲展宽分幅相机的时间分辨率能达到最优.

紫金白溪自然保护区白鹇活动节律分析

2020年7月至2022年8月,利用红外相机技术对广东省紫金白溪自然保护区内白鹇的日活动节律进行了调查和分析.分析结果显示:白鹇的行为具有明显的昼行性,日活动节律有2个高峰期,分别出现在6∶00—7∶00和15∶00—16∶00,活动低谷期在12∶00.白鹇在不同季节内的日活动节律存在变化,冬夏季差异最为显著,日活动节律重叠程度最低(Δ=0.860,P<0.01).在相同季节的不同海拔上白鹇的活动节律也存在一定差异,主要体现在夏季.夏季高海拔带个体活动比低海拔带个体活动频繁,早晨更为活跃;低海拔带个体活动则在午后更为活跃.