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回旋加速器主磁铁镶条再加工工艺研究

制造技术与机床 2024年第7期 139-143页

作者：凌丽王飞邢建升边天剑陆锦荣安世忠中国原子能科学研究院北京102413

回旋加速器主磁场测量与垫补是回旋加速器技术研究的一个重要方向。为实现回旋加速器主磁场垫补理论要求,其垫补方式可采用边缘垫补方式。该方式要求加工的镶条边缘曲线的精度优于0.02 mm。然而,镶条初次加工方式为配做形式,本身镶条材... 详细信息

回旋加速器主磁场测量与垫补是回旋加速器技术研究的一个重要方向。为实现回旋加速器主磁场垫补理论要求,其垫补方式可采用边缘垫补方式。该方式要求加工的镶条边缘曲线的精度优于0.02 mm。然而,镶条初次加工方式为配做形式,本身镶条材料硬度低、形状薄且长,在强磁场条件下,细微扰动就会引起磁场剧烈变化,实际需要进行垫补加工量非常小。故保证镶条边缘曲线再加工精度是实现回旋加速器功能非常重要的工作。文章从边缘理论曲线获得方式出发,提出加工精度具体要求和边缘曲线加工的实现方式,并考虑其坐标系关系,设计了一种保证镶条边缘曲线再加工精度的工装。该工装可同时固定两根镶条,提供合适的参考点,实现镶条在加速器上的位置复现。该工装应用于16 Mev加速器镶条垫补加工,每次垫补结果机械测量误差在0.02 mm,磁场复测后实际加工磁场与理论垫补磁场精度好于10-3。

关键词：回旋加速器磁场垫补工装装置装配工艺

Nonlinear dynamic optimization of CEPC booster lattice

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Radiation Detection Technology and Methods 2017年第2期1卷 89-98页

作者： tianjian bian Jie Gao Xiaohao Cui Chuang Zhang Institute of High Energy Physics BeijingChina University of Chinese Academy of Sciences BeijingChina

Aims In September 2012,Chinese scientists proposed a circular electron positron collider(CEPC)at 240 GeV center of mass for Higgs *** CEPC booster(CEPCB)provides 120 GeV electron and positron beams to the CEPC *** The phase-shift-optimizing method is proposed and used in the CEPC booster *** also explain the physics picture of this method,and then some numerical results are listed to confirm our *** With the phase-shift-optimizing method,the dynamic aperture increases in varying degrees,especially for offmomentum *** In this paper,we find out the key point of CEPC booster lattice *** phase-shift-optimizing method,a CEPC booster lattice design with good dynamic aperture is given.

关键词： Circular Electron Positron Collider Booster Nonlinear dynamics Phase-shift-optimizing method

多目标进化算法在等时性固定场交变梯度加速器物理设计中的应用研究

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原子能科学技术 2021年第S2期55卷 429-434页

作者：边天剑张天爵李明安世忠王川中国原子能科学研究院回旋加速器研究设计中心北京102413

由于等时性固定场交变梯度加速器具有连续束、强聚焦等优点,逐渐成为研究热点。等时性固定场交变梯度加速器的物理设计问题可归结为具有多个设计目标、可调节变量与条件限制的最优化问题。多目标进化算法的发展给复杂的最优化问题提供... 详细信息

由于等时性固定场交变梯度加速器具有连续束、强聚焦等优点,逐渐成为研究热点。等时性固定场交变梯度加速器的物理设计问题可归结为具有多个设计目标、可调节变量与条件限制的最优化问题。多目标进化算法的发展给复杂的最优化问题提供了解决方案。将多目标进化算法应用于等时性固定场交变梯度加速器的优化中可提高设计效率。为了验证该优化方法的有效性,针对70 MeV与1 GeV等时性固定场交变梯度加速器进行了物理设计优化,并达到了预期设计目标。

关键词：多目标进化算法基因遗传算法等时性固定场交变梯度加速器

The formation and evolutionary characteristics of organic matter and pyrites in the continental shales of the 3^(rd)submember of Chang 7 Member,Yanchang formation,Ordos Basin,China

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Energy Geoscience 2024年第2期5卷 31-39页

作者： Ruikang bian State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development Beijing 102206China Key Laboratory of Shale Oil and Gas Exploration&Production Technology SinopecBeijing 102206China SINOPEC Exploration&Production Research Institute Beijing102206China

Through microscopic analyses(e.g.,organic macerals,thin section observation,scanning electron microscope(SEM)imaging of fresh bedding planes via argon ion milling,and energy spectrum tests)combined with Rock-Eval analyses,this study systematically investigated the organic matter and pyrites in the continental shales in the 3^(rd)submember of the Chang 7 Member(Chang 7^(3)submember)in the Yanchang Formation,Ordos Basin and determined their types and the formation and evolutionary *** results are as *** organic matter of the continental shales in the Chang 7^(3)submember is dominated by amorphous bituminites and migrabitumens,which have come into being since the early diagenetic stage and middle diagenetic stage A,*** formation and transformation of organic matter is a prerequisite for the formation of *** Ordos Basin was a continental freshwater lacustrine basin and lacked sulphates in waters during the deposition of the Chang 7 ***,the syndiagenetic stage did not witness the formation of large quantities of *** the basin entered early diagenetic stage A,large quantities of sulfur ions were released as the primary organic matter got converted into bituminites and,accordingly,pyrites started to ***,this stage featured poorer fluid and spatial conditions compared with the syndepositional stage due to withdraw of water,the partial formation of bituminites,and a certain degree of *** a result,large quantities of pyrrhotite failed to transition into typical spherical framboidal pyrites but grew into euhedral monocrystal *** addition,pyrites are still visible in the migrabitumens in both microfractures and inorganic pores of mudstones and shales,indicating that the pyrite formation period can extend until the middle diagenetic stage A.

关键词： Organic matter Pyrite Formation and evolution Continental shale Chang 7^(3)submember Ordos Basin

Long-wave instabilities

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Science China Mathematics 2024年第8期67卷 1761-1776页

作者： Dongfen bian Emmanuel Grenier School of Mathematics and Statistics Beijing Institute of TechnologyBeijing 100081China Unité de Mathématiques Pures et Appliquées CNRS UMR 5669Ecole Normale Supérieure de LyonLyon 69007France

This paper aims to give a detailed presentation of long-wave instabilities of shear layers for NavierStokes equations,and in particular to give a simple and easy-to-read presentation of the study of the OrrSommerfeld equation and to detail the analysis of its *** these analyses,we prove the existence of long-wave instabilities in the cases of slowly rotating fuids,slightly compressible fuids,or fuids with Navier boundary conditions,under smallness conditions.

关键词： Navier-Stokes equations boundary layers Prandtl equations

Vibration harmonic suppression technology for electromagnetic vibrators based on an improved sensorless feedback control method

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Frontiers of Information Technology & Electronic Engineering 2024年第3期25卷 472-483页

作者： Wei LI Junning CUI Xingyuan bian Limin ZOU Centerof Ultra-precision Optoelectronic Instrument Engineering Harbin Institute of TechnoogyHarbin 0080China Key Lab of Ultra-precision Intlligent Instrumentation(Harbin Institute of Technology).Ministry of Industry and Information Technology Harbin 150080China

To realize low harmonic distortion of the vibration waveform output from electromagnetic vibrators,we propose a vibration harmonic suppression technology based on an improved sensorless feedback control *** changing the original driving circuit,the alternating current(AC)equivalent resistance of the driving coil is used to obtain high-precision vibration velocity information,and then a simple and reliable velocity feedback control system is *** the study of the effect of different values of key parameters on the system,we have achieved an effective expansion of the velocity characteristic frequency band of low-frequency vibration,resulting in an enhanced harmonic suppression capability of velocity feedback *** present extensive experiments to prove the effectiveness of the proposed method and make comparisons with conventional control *** the frequency range of 0.01-1.00 Hz,without using any sensors,the method proposed in this study can reduce the harmonic distortion of the vibration waveform by about 40%compared to open-loop control and by about 20%compared to a conventional sensorless feedback control method.

关键词： Vibration calibration Electromagnetic vibrators Harmonic suppression Sensorless control method Velocity feedback control

USP45 acts as an oncogene to regulate the proliferation of esophageal cancer cells

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Genes & Diseases 2024年第5期11卷 44-47页

作者： Kai Li Qian Wang Hua bian Zhang Zhongjing College of Chinese Medicine Henan Key Laboratory of Zhang Zhongjing Formulae and Herbs for ImmunoregulationNanyang Institute of TechnologyNanyangHenan 473004China College of Orthopaedics and Traumatology Henan University of Chinese MedicineZhengzhouHenan 450046China

Deubiquitinases(DUBs)are a class of enzymes that are able to reverse the process of ubiquitination.1 Extensive research has revealed that there are more than 100 DUBs found in humans,which are classified into seven main families:ubiquitin-specific proteases(USPs),ubiquitin carboxyl-terminal hydrolases,the Machado-Joseph disease domain superfamily,the otubain/ovarian tumor-domain containing proteins,the ZUFSP(Zinc finger with UFM1-specific peptidase domain protein)family,the JAB1/MPN/MOV34 proteases,and the novel motif interacting with ubiquitin-containing DUB *** DUBs are cysteine proteases,except the JAB1/MPN/MOV34 proteases,which are Zn^(2+) metalloproteases.

关键词： esophageal cancer Zinc

Power-Domain Collision-Tolerant Random Access Method with Auxiliary Beam for Satellite Internet of Things:A New Solution

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China Communications 2024年第8期21卷 236-248页

作者： Xu Yuanyuan Liu Ziwei bian Dongming Zhang Gengxin School of Communications and Information Engineering Nanjing University of Posts and TelecommunicationsNanjing 210003China Institute of Communications Engineering PLA University of Science and TechnologyNanjing 210007China

There are numerous terminals in the satellite Internet of Things(IoT).To save cost and reduce power consumption,the system needs terminals to catch the characteristics of low power consumption and light *** regular random access(RA)protocols may generate large amounts of collisions,which degrade the system throughout *** near-far effect and power control technologies are not applicable in capture effect to obtain power difference,resulting in the collisions that cannot be *** fact,the optimal design at the receiving end can also realize the condition of packet power domain separation,but there are few relevant *** this paper,an auxiliary beamforming scheme is proposed for power domain signal *** adds an auxiliary reception beam based on the conventional beam,utilizing the correlation of packets in time-frequency domain between the main and auxiliary beam to complete signal *** roll-off belt of auxiliary beam is used to create the carrier-to-noise ratio(CNR)*** paper uses the genetic algorithm to optimize the auxiliary beam *** results show that the proposed scheme outperforms slotted ALOHA(SA)in terms of system throughput per-formance and without bringing terminals additional control burden.

关键词： beamforming non-orthogonal multiple access random access satellite Internet of Things

Wetting-drying effect on the strength and microstructure of cementphosphogypsum stabilized soils

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 1049-1058页

作者： Lingling Zeng Xia bian Jiaxing Weng Tao Zhang College of Civil Engineering Zhejiang University of TechnologyHanzhou310014China Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering Hohai UniversityNanjing210098China State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyXuzhou221116China Jiangsu Water Source Company Ltd.of the Eastern Route of the South-to-North Water Diversion Project Nanjing210000China Power China Zhongnan Engineering Corporation Limited Changsha410027China

Phosphogypsum has often been used as an effective and environmentally friendly binder for partial replacement of cement,improving the engineering properties of slurries with high water ***,the influence of phosphogypsum on the physicomechnical properties of stabilized soil subjected to wettingedrying cycles is not well understood to *** this study,the effect of phosphogypsum on the durability of stabilized soil was studied by conducting a series of laboratory experiments,illustrating the changes in mass loss,pH value and unconfined compressive strength(qu)with wettingdrying *** test results showed that the presence of phosphogypsum significantly restrained the mass loss in the early stage(lower than the 4th cycle),which in turn led to a higher qu of stabilized soil than that without *** the 4th cycle,a sudden increase in mass loss was observed for stabilized soil with phosphogypsum,resulting in a significant drop in qu to a value lower than those without phosphogypsum at the 6th *** addition,the qu of stabilized soils correlated well with the measured soil pH irrespective of phosphogypsum content for all wettingedrying *** to the microstructure observation via scanning electron microscope(SEM)and X-ray diffraction(XRD)tests,the mechanisms relating the sudden loss of qu for the stabilized soils with phosphogypsum after the 4th wetting-drying cycle are summarized as follows:(i)the disappearance of ettringite weakening the cementation bonding effect,(ii)the generation of a larger extent of microcrack,and(iii)a lower pH value,in comparison with the stabilized soil without phosphogypsum.

关键词： Wetting-drying Phosphogypsum Microstructure Durability