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The machine learning implementation and theoretical foundations of intelligent control of accelerator particle beams

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Science China(Physics,Mechanics & Astronomy) 2024年

作者： xueqing yan State Key Laboratory of Nuclear Physics and Technology Peking University

The intelligent control of accelerator particle beams,achieved through machine learning, offers a new opportunity for the design and regulation of high-power, high-intensity accelerators. In recent years, this technology has been applied in several practical systems. For instance, the DeepMind team successfully used reinforcement learning to control the plasma in a Tokamak device with 19 control magnets [1].

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A recent burst of gene duplications in Triticeae

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Plant Communications 2022年第2期3卷 1-12页

作者： Xiaoliang Wang xueqing yan Yiheng Hu Liuyu Qin Daowen Wang Jizeng Jia Yuannian Jiao State Key Laboratory of Systematic and Evolutionary Botany Institute of BotanyChinese Academy of SciencesBeijing 100093China University of Chinese Academy of Sciences Beijing 100049China College of Agronomy Collaborative Innovation Center of Henan Grain CropsHenan Agricultural UniversityZhengzhouHenan 450046China Institute of Crop Sciences Chinese Academy of Agricultural SciencesBeijing 100081China

Gene duplication provides raw genetic materials for evolution and potentially novel genes for crop *** two seminal genomic studies of Aegilops tauschii both mentioned the large number of genes independently duplicated in recent years,but the duplication mechanism and the evolutionary significance of these gene duplicates have not yet been ***,we found that a recent burst of gene duplications(hereafter abbreviated as the RBGD)has probably occurred in all sequenced Triticeae *** investigations of the characteristics of the gene duplicates and their flanking sequences suggested that transposable element(TE)activity may have been involved in generating the *** also characterized the duplication timing,retention pattern,diversification,and expression of the duplicates following the evolution of *** subgenome-specific comparisons of the duplicated gene pairs clearly supported extensive differential regulation and related functional diversity among such pairs in the three subgenomes of bread ***,several duplicated genes from the RBGD have evolved into key factors that influence important agronomic traits of *** results provide insights into a unique source of gene duplicates in Triticeae species,which has increased the gene dosage together with the two polyploidization events in the evolutionary history of wheat.

关键词： gene duplication transposable elements gene dosage hexaploid wheat Triticeae agronomic traits

Issues of the Holocene transgression on the southern plain of the Changjiang Delta

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Acta Oceanologica Sinica 1988年第4期7卷 578-590页

作者： yan Qinshang and Hong xueqing Department of Geography, East China Normal University, Shanghai, China China

The paper deals with the question of Holocene transgression on the southern plain of the Changjiang *** the beginning of the transgression, the paleovalleys of the Changjiang and Qiantang Rivers were covered by sea water at *** shoreline of 8000-7500 yr BP coincided with the -7m isobath of paleotopography. Sea level had already been the present level about 7000-6500 years ago, and the Holocene transgression reached its maximum extent. During the period, the Changjiang and Qiantang Rivers and the Dongtiaoxi valley were turned into estuaries; the eastern area of Shanghai became a shallow sea; some of the bays and lagoons were distributed on the Hang-Jia-Hu and Tao-Ge Plain; the hilly region around the Taihu Lake was coastal marsh and freshwater swamp. Gangshen on the west of Shanghai was formed 7000-4000 yr BP, and during the last 4000 years, the eastern coastal plain of Shanghai advanced quickly toward the sea, and partial clear land of the western Taihu Lake was enclosed and charged into a fre

关键词： Ho Issues of the Holocene transgression on the southern plain of the Changjiang Delta

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岭南民族融合与经济文化类型嬗变研究

广西民族研究 2010年第1期 165-171页

作者：严雪晴广东技术师范学院民族学院民族学硕士生广州510650

民族融合是促进岭南经济文化类型嬗变的重要因素,不仅加速了岭南地区生态环境的变化,促进其生计方式的变迁,而且推动了岭南地区民族文化的发展。经济文化类型嬗变是吸引和加速岭南地区民族融合的物质基础。从岭南早期的渔猎文明、稻作... 详细信息

民族融合是促进岭南经济文化类型嬗变的重要因素,不仅加速了岭南地区生态环境的变化,促进其生计方式的变迁,而且推动了岭南地区民族文化的发展。经济文化类型嬗变是吸引和加速岭南地区民族融合的物质基础。从岭南早期的渔猎文明、稻作文明到后来的商贸文明,都镂刻着民族融合的历史痕迹。经济文化类型嬗变加快了民族族内融合的力度,推动着民族族际融合进一步深化,形塑着岭南民族融合的基本格局。

关键词：岭南民族融合经济文化类型

Human radiological safety assessment for petawatt laser-driven ion acceleration experiments in CLAPA-T

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Matter and Radiation at Extremes 2024年第4期9卷 8-15页

作者： Xiaopeng Zhang Jiarui Zhao Shengxuan Xu Xun Chen Ying Gao Shiyou Chen Kun Zhu xueqing yan Wenjun Ma State Key Laboratory of Nuclear Physics and Technology and Key Laboratory of HEDP of the Ministry of EducationCAPTPeking UniversityBeijing 100871China Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsCASBeijing 100049China Beijing Laser Acceleration Innovation Center HuairouBeijing 101400China Institute of Guangdong Laser Plasma Technology BaiyunGuangzhou 510540China

The newly built Compact Laser Plasma Accelerator-Therapy facility at Peking University will deliver 60 J/1 Hz laser pulses with 30 fs *** by this petawatt laser facility,proton beams with energy up to 200 MeV are expected to be generated for tumor *** high-repetition operation,both prompt radiation and residual radiation may cause safety ***,human radiological safety assessment before commissioning is *** this paper,we simulate both prompt and residual radiation using the Geant4 and FLUKA Monte Carlo codes with reasonable proton and as-produced electron beam *** find that the prompt radiation can be shielded well by the concrete wall of the experimental hall,but the risk from residual radiation is nonnegligible and necessitates adequate radiation *** the basis of the simulation results,we discuss the constraints imposed by radiation safety considerations on the annual working time,and we propose radiation cooling strategies for different shooting modes.

关键词： laser prompt acceleration

Measurements of plasma density profile evolutions with a channel-guided laser

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High Power Laser Science and Engineering 2023年第6期11卷 199-212页

作者： Tong yang Zhen Guo yang yan Minjian Wu Yadong Xia Qiangyou He Hao Cheng Yuze Li yanlv Fang yanying Zhao xueqing yan Chen Lin State Key Laboratory of Nuclear Physics and Technology and Key Laboratory of HEDP of the Ministry of EducationCAPTPeking UniversityBeijingChina Beijing Laser Acceleration Innovation Center BeijingChina Institute of Guangdong Laser Plasma Technology GuangzhouChina

The discharged capillary plasma channel has been extensively studied as a high-gradient particle acceleration and transmission medium.A novel measurement method of plasma channel density profiles has been employed,where the role of plasma channels guiding the advantages of lasers has shown strong ***,we have studied the high-order transverse plasma density profile distribution using a channel-guided laser,and made detailed measurements of its evolution under various *** paraxial wave equation in a plasma channel with high-order density profile components is analyzed,and the approximate propagation process based on the Gaussian profile laser is obtained on this basis,which agrees well with the simulation under phase *** the experiments,by measuring the integrated transverse laser intensities at the outlet of the channels,the radial quartic density profiles of the plasma channels have been *** precisely synchronizing the detection laser pulses and the plasma channels at various moments,the reconstructed density profile shows an evolution from the radial quartic profile to the quasi-parabolic profile,and the high-order component is indicated as an exponential decline tendency over *** affecting the evolution rate were investigated by varying the incentive source and capillary *** can be found that the discharge voltages and currents are positive factors quickening the evolution,while the electron-ion heating,capillary radii and pressures are negative *** plausible explanation is that quartic profile contributions may be linked to plasma *** work helps one to understand the mechanisms of the formation,the evolutions of the guiding channel electron-density profiles and their dependences on the external controllable *** provides support and reflection for physical research on discharged capillary plasma and optimizing plasma channels in various applications.

关键词： channel-guided laser discharge capillary plasma density profile

Extremely powerful and frequency-tunable terahertz pulses from a table-top laser–plasma wiggler

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High Power Laser Science and Engineering 2023年第6期11卷 249-255页

作者： Jie Cai Yinren Shou Yixing Geng Liqi Han Xinlu Xu Shuangchun Wen Baifei Shen Jinqing Yu xueqing yan State Key Laboratory of Nuclear Physics and Technology and Key Laboratory of HEDP of the Ministry of EducationCAPTPeking UniversityBeijingChina Hunan Provincial Key Laboratory of High-Energy Scale Physics and Applications School of Physics and ElectronicsHunan UniversityChangshaChina Center for Relativistic Laser Science Institute for Basic ScienceGwangjuRepublic of Korea Shanghai Normal University ShanghaiChina Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuanChina Guangdong Laser Plasma Institute GuangzhouChina

The production of broadband,terawatt terahertz(THz) pulses has been demonstrated by irradiating relativistic lasers on solid ***,the generation of extremely powerful,narrow-band and frequency-tunable THz pulses remains a ***,we present a novel approach for such THz pulses,in which a plasma wiggler is elaborated by a table-top laser and a near-critical density *** such a wiggler,the laser-accelerated electrons emit THz radiations with a period closely related to the plasma *** theoretical model and numerical simulations predict that a THz pulse with a laser-THz energy conversion of over 2.0%,an ultra-strong field exceeding 80 GV/m,a divergence angle of approximately 200 and a center frequency tunable from 4.4 to 1.5 THz can be generated from a laser of 430 ***,we demonstrate that this method can work across a wide range of laser and plasma parameters,offering potential for future applications with extremely powerful THz pulses.

关键词： laser plasma terahertz wiggler

Progress in the beam commissioning of separated function RFQ accelerator

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Science China(Physics,Mechanics & Astronomy) 2011年第S2期54卷 222-224页

作者： MingLei Kang (1) YuanRong Lu (1) Zhi Wang (1) Kun Zhu (1) xueqing yan (1) ZhiYu Guo (1) ShuLi Gao (1) ShiXiang Peng (1) Ao Liu (2) JiaXun Fang (1) JiaEr Chen (1) 1. State Key Laboratory of Nuclear Physics and Technology Peking University Beijing 100871 China2. Department of Physics Indiana University Bloomington IN 47405 USA

Separated Function RFQ (SFRFQ) was proposed as a post accelerator of RFQ to accelerate heavy ions at low frequency. It introduces gap accelerating in the quadrupole electrodes, and therefore it has higher accelerating efficiency than the conventional RFQ accelerator. The first SFRFQ prototype cavity has been specially designed and constructed as a post accelerator to accelerate O+ beam from 1.03 MeV to 1.64 MeV. Based on accomplishment of low power measurement and high power test, the beam commissioning was carried out to verify its feasibility. The measured energy gain per cell of SFRFQ is 45 keV, which is about 60% higher than that of Peking University Integral Split Ring (ISR) RFQ.

关键词： separated function RFQ beam commissioning energy spectrum

CXCL5 promotes lipogenesis and lipoapoptosis of hepatocytes through NLRP3-mediated IL-1β secretion in Kupffer cells

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CXCL5 promotes lipogenesis and lipoapoptosis of hepatocytes ...