检索结果-南通市图书馆

Development of a low-loss magnetic-coupling pickup for 166.6-MHz quarter-wave beta=1 superconducting cavities

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

Nuclear Science and Techniques 2020年第9期31卷 25-32页

作者： Tong-Ming Huang Pei Zhang Zhong-Quan Li Xin-Ying Zhang Hai-Ying Lin Qiang Ma Fan-Bo Meng Wei-Min Pan Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Key Laboratory of Particle Acceleration Physics and Technology IHEPCASBeijing 100049China School of Nuclear Sciences and Technology University of Chinese Academy of SciencesBeijing 100049China

166.6-MHz quarter-waveβ=1 superconducting cavities have been adopted for the High Energy Photon Source,a 6-GeV diffraction-limited synchrotron light source currently under construction.A large helium jacket was required to accommodate the enlarged cavity beam pipe for the heavy damping of higher-order modes;the original electric-probe pickup thus becomes inevitably long with unfavorable mechanical properties.Relocated to an existing high-pressure-rinsing port,a magnetic-loop pickup was designed,characterized by low radio-frequency and cryogenic losses and being multipacting-free and insensitive to manufacturing and assembly tolerances.The consequent removal of the original pickup port from the cavity largely simplified the helium jacket fabrication and may also reduce cavity contamination.This paper presents a comprehensive design of a low-loss magnetic-coupling pickup for quarter-waveβ=1 superconducting cavities.The design can also be applied to other non-elliptical structures.

关键词： pickup Magnetic coupling Quarter-wave cavity Superconducting cavity Low loss Synchrotron light source

Performance analysis of a spring-tooth drum pickup of straw baler via coupling simulation

在线全文

学校读者我要写书评

暂无评论

International Journal of Agricultural and Biological Engineering 2021年第4期14卷 159-165页

作者： Qingqing Wang Yongcheng Jiang Lianhao Li Junwei Qin Liqing Chen School of Engineering Anhui Agricultural UniversityHefei 230036China Laboratory of Engineering of Intelligent Agricultural Machinery Equipment Anhui ProvinceHefei 230036China School of Mechanical Engineering Jiamusi UniversityJiamusi 154007HeilongjiangChina School of Mechanical and Electrical Engineering Henan Agricultural UniversityZhengzhou 450002China

In order to solve the problem of poor working performance due to incidental picking-up loss of a spring-tooth drum pickup,the coupling analysis approach of Automated Dynamic Analysis of Mechanical Systems(ADAMS)and Discrete Element Method(DEM)was proposed to reveal its motion characteristics.The coupled ADAMS-DEM method was used to construct the pickup simulation model with rice straw as the object.The validation tests were carried out in the field with different operating forward speeds and straw coverages.The results showed that when the baler worked with a rake,the straw loss rate tended to rise with the increase of the operating speed and the straw coverage.Tests results indicated periodic peaks and valleys of the forces between the rollers and the track chute,which could increase the wear of the track chute.In addition,the movement and variation of the straw and the distribution of different straw lengths after picking up were analyzed.The research results can provide a reference for the design and optimization of a pickup in the later period.

关键词： ADAMS-DEM coupling loss rate pickup straw coverage straw baler

Practical Study of the Sports Garbage pickup Tournament in Japan-Sports Events to Solve Social Problems

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

Journal of Sports Science 2019年第2期7卷 56-64页

作者： Masamichi Aihara Faculty of Human Sciences Osaka University of Economics2-2-8 OsumiHigashiyodogawa-kuOsaka 533-8533Japan

The Sports Garbage pickup Tournament is a sports event that incorporates elements of competition into cleaning activities,as opposed to traditional cleaning activities.As of the end of December 2016,a total of 552 Sports Garbage pickup Tournaments have been held,mobilizing a cumulative total number of 62,989 people.As each tournament brings a revenue of over 300,000 yen,the total sales so far would be more than 165,000,000 yen.This game was recently reported on the International Olympic Committee channel.The garbage issue,a social problem for local communities,should be solved by residents,visitors,and workers themselves through sports,cooperating with local governments.This is an eco-friendly sport aimed at“solving local social problems through sports.”Sports Garbage pickup Tournaments can be held anywhere,inside the city or in a natural environment.In addition,the competition allows participants to visually understand the environmental capacity of garbage produced in the community,as the points are weighted according to the types of garbage.The Sports Garbage pickup Tournament is an educational program for sustainable development with emphasis on experience,pursuit,and practice,and also an action-based program aimed at promoting spontaneous action.This is an optimal competition for participants to acquire skills through mutual communication.As children,adults,and people with disabilities can play together,the competition will promote communication across the generations.

关键词： Sports garbage pickup tournament sports event sports innovation environment social problem

Study on bed load transport for uniform sediment in laminar flow

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

Science China(Technological Sciences) 2010年第9期53卷 2414-2422页

作者： YANG FengGuang,LIU XingNian,CAO ShuYou,YANG KeJun & HUANG Er State Key Laboratory of Hydraulics and Mountain River Engineering,Sichuan University,Chengdu 610065,China State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University Chengdu China

Previous studies focused on the bed load transport rate for the condition of turbulent flow,while the knowledge of sediment transport in laminar flow is very limited.As an extreme case to reflect the viscous effect on sediment transport,sediment transport in laminar flow is considered in this paper.There are at least two factors affecting the transport rate of sediment under laminar flow conditions: (1) fluid forces;(2) particle to particle interactions.Together,these two factors represent the physical transport system.First,an exposure degree Probability Density Function (PDF) is developed to explore how the transport rate can be associated with characteristics of laminar flow and this factor reflects the particle to particle interactions,and the pickup probability equation in the absence of turbulence is developed based on the stochastic approach which reflects the exposure degree influence.Then,the formulas to calculate the critical shear stress of incipient motion and the bed load transport rate of fine uniform sediment are established.The derivation is made mainly based on Einstein’s bed load theory;we choose Einstein’s equation to model this system because we believe that the probabilistic approach taken is an appropriate way to account for the spatial and temporal variations in the forces causing sediment transport.These formulas have been tested against a wide range of existing laboratory data and compared with other existing empirical or semiempirical methods.The predictions by these newly proposed formulas are very good.

关键词： exposure degree bed load transport rate pickup probability laminar flow shear stress

Beam position monitors as precise phase pickups for beam energy measurement at the Compact Pulsed Hadron Source

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2019年第2期30卷 1-9页

作者： Min-Wen Wang Qing-Zi Xing Shu-Xin Zheng Zhong-Ming Wang Meng-Tong Qiu Xia-Ling Guan Xue-Wu Wang Wen-Hui Huang Laboratory of Particle and Radiation Imaging Ministry of EducationTsinghua University Laboratory for Advanced Radiation Sources and Application Tsinghua University Department of Engineering Physics Tsinghua University State Key Laboratory of Intense Pulsed Radiation Simulation and Effect Northwest Institute of Nuclear Technology

The 13-MeV proton linac of the Compact Pulsed Hadron Source(CPHS) at Tsinghua University, China,is composed of a 50-keV electron cyclotron resonance proton source, a 3-MeV four-vane-type radio-frequency quadrupole(RFQ) accelerator, and a drift tube linac(DTL). Precise measurement of the beam energies at the exit of the RFQ and the DTL is critical for DTL commissioning. Two button-type beam position monitors(BPMs) installed downstream of the RFQ are used to perform the measurement using a time-of-flight method. The effects of several factors on phase measurement accuracy are analyzed. The phase measurement accuracy of the BPMs at CPHS is better than ± 1.03° at 325 MHz after corrections,corresponding to an energy measurement error of± 0.07%. The beam energy measured at the exit of the RFQ is 2.994 ± 0.0022 MeV,which is consistent with the design value.

关键词： Beam energy Time of flight Beam position monitor Phase pickup

在线全文

学校读者我要写书评

暂无评论

一种柔性侧围生产线开发

时代汽车 2017年第3期 79-80页

作者：陈周生傅伟洪俊上汽通用五菱汽车股份有限公司广西柳州市545007

文章介绍了一种简单的柔性侧围生产线,从工艺布局、工装夹具及零件吊运三个方面阐述其开发的过程。这种生产线方式能够满足高产量、简单柔性化的生产要求。

关键词：柔性工艺布局工装夹具 pickup