检索结果-南通市图书馆

Hourly energy consumption characteristics of metro rail transit:Train traction versus station operation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy and Built Environment

Energy and Built Environment 2023年第5期4卷 568-575页

作者： Bowen Guan Xiaohua Liu Tao Zhang xinke wang School of Human Settlements and Civil Engineering Xi’an Jiaotong UniversityXi’anShaanxi710054China Department of Building Science Tsinghua UniversityBeijing 100084China

The electricity consumption of the urban metro system can be mainly divided into the following two categories:the electricity consumption for train traction(E_(t))and the electricity consumption for station operation(E_(s)).Although understanding the hourly fluctuation characteristics of E_(t) and E_(s) contributes to renewable energy inte-gration and achieving carbon emission reduction of the metro system,the hourly fluctuation characteristics have been poorly reported in the literature.Thus,a typical underground non-transfer metro station of a city’s metro system in the North China Plain is selected in this study,and E_(t) and E_(s) were monitored to portray their hourly fluctuation characteristics.Results reveal that the hourly E_(t) shows a significant intraday“U”shape on weekdays,indicating two symmetric peaks in morning and evening rush hours.While the hourly E_(s) shows an intraday“flat”shape,indicating it is nearly free from the effect of rush hour.Moreover,it is statistically proved that the train frequency is the core influencing factor resulting in the intraday fluctuation of hourly E_(t).In the case study,when the train frequency increases from the mean(20 trains per hour)to maximum(32 trains per hour),the hourly E_(t) will increase by 53.4%.

关键词： Urban rail transit Energy consumption Hourly fluctuation Train traction Station operation Carbon emission reduction

Highly efficient vectorial field manipulation using a transmitted tri-layer metasurface in the terahertz band

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Opto-Electronic Advances 2023年第2期6卷 27-37页

作者： Huan Zhao xinke wang Shutian Liu Yan Zhang Department of Physics Harbin Institute of TechnologyHarbin 150001China Beijing Key Laboratory of Metamaterials and Devices Key Laboratory of Terahertz OptoelectronicsMinistry of EducationBeijing Advanced Innovation Center for Imaging Theory and TechnologyDepartment of PhysicsCapital Normal UniversityBeijing 100048China

Polarization is a basic characteristic of electromagnetic waves that conveys much optical information owing to its many states.The polarization state is manipulated and controlled for optical information security,optical encryption,and optical communication.Metasurface devices provide a new way to manipulate wave-fronts of light.A single ultrathin metasurface device can generate and modulate several differently polarized light fields,and thus carries optical information in several different channels.Terahertz(THz)waves have become widely used as carrier waves for wireless communication.Compact and functional metasurface devices are in high demand for THz elements and systems.This paper proposes a tri-layer metallic THz metasurface for multi-channel polarization generation and phase modulation with a high efficiency of approximately 80%.An azimuthally polarized THz vectorial beam generator is realized and characterized for use as a THz polarization analyzer.The incident polarization angle can be observed graphically with high accuracy.Moreover,a vectorial hologram with eight channels for different linear polarization states is demonstrated experimentally.The information in different holograms can be hidden by choosing the polarization channel for detection.This work contributes to achieving multi-functional metasurface in the THz band and can benefit THz communication and optical information security.

关键词： terahertz device polarization state hologram high-efficiency device

Terahertz generation from laser-induced plasma

在线全文

学校读者我要写书评

暂无评论

Opto-Electronic Science 2022年第8期1卷 41-67页

作者： Wenfeng Sun xinke wang Yan Zhang Department of Physics Capital Normal UniversityBeijing 100048China Beijing Key Lab of Metamaterials and Devices and Key Laboratory of Terahertz OptoelectronicsMinistry of EducationBeijing 100048China

Interest of the research in terahertz(THz)wave has been strongly motivated by its wide applications in the fields of physics,chemistry,biology,and engineering.Developing efficient and reliable THz source is of uttermost priority in these researches.Numerous attempts have been made in fulfilling the THz generation.Greatly benefited from the progress of the ultrafast pulses,the laser-induced-plasma is one of the auspicious tools to provide desirable THz waves,owing to its superiorities in high power threshold,intense THz signal,and ultrawide THz spectrum.This paper reviews the physics and progress of the THz generation from the laser-induced plasmas,which are produced by gas,liquid,and solid.The characteristics of the emitted THz waves are also included.There are many complicated physical processes involved in the interactions of laser-plasma,making various laser-plasma scenarios in the THz generations.In view of this,we will only focus on the THz generation classified by physical mechanisms.Finally,we discuss a perspective on the future of THz generation from the laser-induced plasma,as well as its involved challenges.

关键词： terahertz generation ultrafast pulses laser-induced plasma

Moire meta-device for flexibly controlled Bessel beam generation

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2023年第1期11卷 100-108页

作者： GUOCUI wang TIAN ZHOU JIANZHOU HUANG xinke wang BIN HU YAN ZHANG Beijing Engineering Research Center for Mixed Reality and Advanced Display School of Optics and PhotonicsBeijing Institute of TechnologyBeijing 100081China Beijing Key Laboratory of Metamaterials and Devices Key Laboratory of Terahertz OptoelectronicsMinistry of EducationBeijing Advanced Innovation Center for Imaging Theory and TechnologyDepartment of PhysicsCapital Normal UniversityBeijing 100048China

High-order Bessel beams are of great interest for most stable long-range optical quantum communications due to their unique nondiffraction,self-healing,and orbital angular-momentum-carrying capabilities.Until now,metasurfaces based on Bessel beam generators are mostly static and focused on generating zero-order Bessel beams.A moirémeta-device made of two cascaded metasurfaces is a simple,effective strategy to dynamically manipulate the wavefront of electromagnetic(EM)waves by mutual rotation between the two metasurfaces.Here,an all-dielectric moirémeta-device integrated with the functions of an axicon and a spiral phase plate to generate terahertz Bessel beams is designed.Not only the order,but also the nondiffraction length of the generated Bessel beam can be continuously tuned.As a proof of concept of the feasibility of the platform,the case of tuning order is experimentally demonstrated.The experimental results are in good agreement with the theoretical expectations.In addition,we also numerically proved that the nondiffraction length of the Bessel beam can be adjusted with the same approach.The moirémeta-device platform is powerful in dynamically manipulating the wavefront of EM waves and provides an effective strategy for continuously controlling the properties of the Bessel beam,which may find applications in optical communications,particle manipulation,and super-resolution imaging.

关键词： Bessel beam continuously

在线全文

学校读者我要写书评

暂无评论

基于计算机视觉的采摘机器人作业优化研究

农机化研究 2024年第8期46卷 235-239页

作者：王新科李凯郑州职业技术学院郑州450121

为进一步提高我国采摘机器人智能化作业水平及采摘效率,基于计算机视觉应用技术展开优化研究。以采摘机器人结构组成为设计基点,运用视觉控制核心理念建立采摘机器人视觉识别处理与控制数学模型,实施相适应的采摘路径规划和系统采摘状... 详细信息

为进一步提高我国采摘机器人智能化作业水平及采摘效率,基于计算机视觉应用技术展开优化研究。以采摘机器人结构组成为设计基点,运用视觉控制核心理念建立采摘机器人视觉识别处理与控制数学模型,实施相适应的采摘路径规划和系统采摘状态输出设计。同时,进行视觉采摘验证试验,结果表明:基于计算机视觉的采摘机器人系统优化正确可行,整机综合采摘效率可达94.61%,系统识别准确率与控制精度分别相对提升了6.12%和5.25%,机器人采摘成功率可提升至95.98%。因此,将计算机视觉处理技术有效应用至采摘机器人设计改进,对于类似农业采摘与收获装备开发研究可提供创新及借鉴思路,推广价值良好。

关键词：采摘机器人计算机视觉视觉控制识别准确率采摘成功率

维普期刊数据库博看期刊

基于DTN路由的多通路精准灌溉系统布局设计

在线全文

学校读者我要写书评

暂无评论

农机化研究 2024年第7期46卷 141-145页

作者：王新科高瑞敏郑州职业技术学院郑州450121

为进一步提升我国智能灌溉装备的综合作业效率,从多通路实施与精准化控制角度展开布局设计。以灌溉系统的作业原理及田间信息获取特征为出发点,建立灌溉网络的DTN路由算法模型,实施网络节点的规划分配与通道布置,形成精准性的逻辑控制... 详细信息

为进一步提升我国智能灌溉装备的综合作业效率,从多通路实施与精准化控制角度展开布局设计。以灌溉系统的作业原理及田间信息获取特征为出发点,建立灌溉网络的DTN路由算法模型,实施网络节点的规划分配与通道布置,形成精准性的逻辑控制流程及节点网络相互执行关系。进行系统性的灌溉试验,结果表明:基于DTN路由算法的多通路精准灌溉系统布局正确可行,信息投递成功率可达94.13%,节点转发率可达96.07%,各信息传递的实时准确,各阀门组件的动作协调,综合灌溉效率实现了高于90%的优化目标,是DTN路由控制理念在灌溉装备领域的应用创新思路之一,具有较好的推广意义。

关键词：智能灌溉精准化控制 DTN路由算法投递成功率节点转发率

Efficient manipulations of circularly polarized terahertz waves with transmissive metasurfaces

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2019年第1期8卷 1033-1041页

作者： Min Jia Zhuo wang Heting Li xinke wang Weijie Luo Shulin Sun Yan Zhang Qiong He Lei Zhou State Key Laboratory of Surface Physics and Key Laboratory of Micro and Nano Photonic Structures(Ministry of Education) and Department of PhysicsFudan University200438 ShanghaiChina Beijing Key Laboratory of Metamaterials and Devices Key Laboratory of Terahertz Optoelectronics(Ministry of Education)and Beijing Advanced Innovation Center for Imaging TechnologyCapital Normal University100048 BeijingChina Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing Green Photonics and Department of Optical Science and EngineeringFudan University200433 ShanghaiChina Collaborative Innovation Center of Advanced Microstructures 210093 NanjingChina

The unrestricted control of circularly polarized(CP)terahertz(THz)waves is important in science and applications,but conventional THz devices suffer from issues of bulky size and low efficiency.Although Pancharatnam-Berry(PB)metasurfaces have shown strong capabilities to control CP waves,transmission-mode PB devices realized in the THz regime are less efficient,limiting their applications in practice.Here,based on Jones matrix analysis,we design a trilayer structure(thickness of ~λ/5)and experimentally demonstrate that the structure can serve as a highly efficient transmissive meta-atom(relative efficiency of ~90%)to build PB metadevices for manipulating CP THz waves.Two ultrathin THz metadevices are fabricated and experimentally characterized with a z-scan THz imaging system.The first device can realize a photonic spin Hall effect with an experimentally demonstrated relative efficiency of ~90%,whereas the second device can generate a high-quality background-free CP Bessel beam with measured longitudinal and transverse field patterns that exhibit the nondiffracting characteristics of a Bessel beam.All the experimental results are in excellent agreement with full-wave simulations.Our results pave the way to freely manipulate CP THz beams,laying a solid basis for future applications such as biomolecular control and THz signal transportation.

关键词： circular polarized Bessel

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

基于阿贝原则的机床主轴误差测量研究

工具技术 2024年第6期58卷 150-152页

作者：杨锐刘宏伟王新科襄阳职业技术学院湖北文理学院机械工程学院

机床测量是误差补偿的前提,分析主轴箱移动时产生的阿贝误差原因,给出主轴箱沿Z轴移动时X方向和Y方向的直线度误差,根据主轴箱直线度误差数据进行建模并给予补偿,结合具体的工程实例验证了阿贝误差补偿的有效性。

关键词：阿贝误差机床测量误差补偿主轴

装配式建筑发展影响因素组态路径研究——基于我国19个省(市)的fsQCA分析

在线全文

学校读者我要写书评

暂无评论

西安石油大学学报（社会科学版） 2024年第1期33卷 83-88页

作者：赛云秀王心可西安石油大学经济管理学院陕西西安710065

基于我国19个省(市)面板数据,运用fsQCA方法探讨了影响装配式建筑发展的组态路径。研究结果表明,单一因素并不构成影响装配式建筑发展的必要条件,而是各条件变量多重并发形成了影响装配式建筑发展的多种组态;产生高装配式建筑发展水平... 详细信息

基于我国19个省(市)面板数据,运用fsQCA方法探讨了影响装配式建筑发展的组态路径。研究结果表明,单一因素并不构成影响装配式建筑发展的必要条件,而是各条件变量多重并发形成了影响装配式建筑发展的多种组态;产生高装配式建筑发展水平的路径分别是经济-产业链-技术驱动型、政府主导的经济与市场驱动型、政府驱动型、技术主导的环境驱动型和政府主导的技术与产业驱动型;产生非高装配式建筑发展水平的路径与产生高装配式建筑发展水平的路径为非对称性。从组态角度为装配式建筑发展提供参考依据。

关键词：装配式建筑影响因素组态视角 fsQCA