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Highly coupled off-resonance lattice design in diffraction-limited light sources

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Nuclear Science and Techniques 2024年第09期 224-234页

作者： Yi-Hao Gong Shun-Qiang Tian xin-zhong liu Shou-Zhi Xuan Li-Yuan Tan Ling-Long Mao Shanghai Advanced Research Institute Chinese Academy of Sciences Shanghai Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai University of Chinese Academy of Sciences

The round-beam operation presents many benefits for scientific experiments regarding synchrotron radiation and the weakening influences of intra-beam scattering in diffraction-limited synchrotron light sources. A round-beam generation method based on the global setting of skew quadrupoles and the application of a non-dominated sorting genetic algorithm was proposed in this study. Two schemes, including large-emittance coupling introduced via betatron coupling and vertical dispersion, were explored in a candidate lattice for an upgrade-proposal of the Shanghai synchrotron radiation facility. Emittance variations with lattice imperfections and their influence on the beam dynamics of beam optic distortions were *** results demonstrated that a precise coupling control ranging from 10 to 100% was achieved under low optical distortion,whereas full-coupling generation and its robustness were achieved by our proposed method by adjusting the skew quadrupole components located in the dispersion-free sections. The Touschek lifetime increased by a factor of 2–2.5.

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Intra-beam scattering and beam lifetime in a candidate lattice of the soft X-ray diffraction-limited storage ring for the upgraded SSRF

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Nuclear Science and Techniques 2021年第8期32卷 57-66页

作者： xin-zhong liu Shun-Qiang Tian Xu Wu Meng Wang Zhen-Tang Zhao Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201204China Shanghai University Shanghai 200444China

New-generation synchrotron light sources are being designed and operated worldwide to provide brighter radiation by reducing the beam emittance to X-ray diffraction ***-beam scattering(IBS)and Touschek scattering in such facilities are significant and require attention because of their ultra-low ***,cure strategies need to be carefully studied to obtain highquality photon *** the Shanghai Synchrotron Radiation Facility Upgrade(SSRF-U),a candidate lattice of the storage ring,reaching the soft X-ray diffraction limit,was designed and presented for the first time in this *** emittance growth and beam lifetime in the SSRF-U storage ring were studied using particle simulations for a series of different machine *** gains with RF frequencies of 100 MHz and 500 MHz were *** with a better filling pattern,a more suitable RF frequency was adopted in the *** variations in the equilibrium beam emittance with beam coupling and bunch-lengthening were identified using *** beam coupling and required bunch-lengthening for the SSRF-U storage ring were thus *** fitness of the beam energy in the SSRF-U was subsequently assessed using the obtained ***,the Touschek scattering and beam lifetime were calculated,and an acceptable total beam lifetime was obtained.

关键词： Diffraction-Limited Storage Ring(DLSR) Shanghai Synchrotron Radiation Facility Upgrade(SSRFU) Intra-Beam Scattering(IBS) Touschek scattering Beam lifetime

Numerical analysis on the influence of vortex motion in a reverse Stairmand cyclone separator by using LES model

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Petroleum Science 2022年第2期19卷 848-860页

作者： Zhu-Wei Gao zhong-xin liu Yao-Dong Wei Cheng-xin Li Shi-Hao Wang xin-Yu Qi Wei Huang School of Chemical Engineering and Technology Hainan UniversityHaikou570228PR China State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing102249PR China Beijing Key Laboratory of Process Fluid Filtration and Separation Beijing102249PR China State Key Laboratory of Marine Resource Utilization in South China Sea College of Materials and Chemical EngineeringHainan UniversityHaikou570228PR China

This study aims to analyze the influence of vortex motion in a reverse Stairmand cyclone separator by using LES *** mathematical analysis indicated that the energy dissipation and the flow characteristics of incompressible fluid are directly related to on the vortex *** results of the Q criterion-based iso-vortex surface could well reflect the tendency of the vortex structure,in which the iso-vortex surface exhibited a distorted distribution rather than around the center *** the turning point of velocity vector,vortices were formed and developed,and the point was the center of the local vortex *** addition,the vortex formed an irregular annular region around the wall at the bottom of vortex *** vortex structure near the dust hopper presented a strong ***,there were two rotating flow in the opposite direction within the dust *** phenomena would affect the separation performance,which was significance to cyclone separator.

关键词： Numerical simulation Cyclone separator Mathematical analysis Vortex motion Local analysis

ID effects on beam dynamics in the SSRF-U storage ring

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Nuclear Science and Techniques 2023年第11期34卷 140-154页

作者： Li‑Yuan Tan Shun‑Qiang Tian xin‑zhong liu Xu Wu Wen‑Zhi Zhang Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201204China

This paper introduces the proposed insertion device(ID)scheme for the Shanghai Synchrotron Radiation Facility *** on this scheme,the influences of the ID radiation on the intra-beam scattering emittance and energy spread were *** distortion caused by the IDs was comprehensively examined and compensated using both local and global ***,a frequency map analysis method was used to identify potentially dangerous resonance *** addition,the dynamic aperture,energy acceptance,and Touschek lifetime were calculated after considering high-order magnetic field errors to ensure that the ID effect did not affect the operation of the storage ring.

关键词： SSRF-U Insertion devices Emittance Beam dynamic

Feedforward compensation of the insertion devices effects in the SSRF storage ring

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Nuclear Science and Techniques 2022年第6期33卷 34-44页

作者： xin-zhong liu Shun-Qiang Tian Xu Wu Meng Wang Zhen-Tang Zhao Bo-Yuan Feng University of Chinese Academy of Sciences Shanghai 201800China Shanghai Institute of Applied Physics Chinese Academy of SciencesBeijing 100049China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201204China Shanghai University Shanghai 200444China Tsinghua University Beijing 100084China

The lattice of the Shanghai Synchrotron Radiation Facility(SSRF) storage ring was upgraded in the Phase-II beamline project, and thus far, 18 insertion devices(IDs) have been installed. The IDs cause closed-orbit distortions, tune drift, and coupling distortions in the SSRF storage ring, all of which are significant issues that require solutions. In this study, an ID orbit feedforward compensation system based on a response matrix using corrector coils was developed, and it was applied to all commissioned IDs in the SSRF storage ring. After correction, the maximum ID-induced horizontal and vertical orbit distortions were less than 5.0 and 3.5 μm, respectively. Some interesting phenomena observed during the measurement process were explained. Additionally, optical and coupling feedforward systems were developed using quadrupole and skew quadrupole magnets installed on the front and back of elliptically polarizing undulators(EPUs). Moreover, over nearly four months of operation, the developed strategy delivered a satisfactory performance in the SSRF storage ring.

关键词： Shanghai Synchrotron Radiation Facility(SSRF) Insertion devices(IDs) Closed-orbit distortion Tune shift Coupling Feedforward

Upconversion luminescent property and EPR study of NaGdF4:Yb3+/Tm3+ synthesized by the hydrothermal method

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Frontiers of Materials Science 2015年第3期9卷 241-246+209页

作者： Jing liu Jing-Ying ZHANG Kai liu Hong-Jian GAO Xiao-Long YU Yang CAO zhong-xin liu Key Laboratory of Ministry of Education for Advanced Materials in Tropical Island Resources Hainan University

Water soluble upconversion(UC) luminescence hexagonal-phase Na Gd F4:Yb3+/Tm3+nanoparticles have been successfully synthesized by the hydrothermal method. XRD, SEM, UC photoluminescence spectra and electron paramagnetic resonance(EPR) spectrum were used to characterize the nanoparticles. The intensity of UC emission region could be controlled through different sodium source and the fluorine source,6PJ!8S7/2emission of Gd3+is also observed at 310 nm. A broad spectrum with a dominant resonance at g of about 2 was observed by the EPR spectrum of the Na Gd F4:Yb3+/Tm3+nanoparticles. The transparent Na Gd F4:Yb3+/Tm3+solution presented naked eye-visible violet-blue light under the 980 nm LD excitation. The current work paves the way for their potential application in infrared tomography and magnetic resonance imaging(MRI).

关键词： hydrothermal method sodium source fluorine source electron paramagnetic resonance (EPR) magnetic resonance imaging (MRI)

Coronary sinus： an important target of catheter ablation of atrial fibrillation

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Chinese Medical Journal 2009年第23期122卷 2912-2913页

作者： ZHANG Ming LI Zhi-zhong liu xin-peng DONG Jian-zeng MA Chang-sheng Department of cardiology Beijing Anzhen Hospital CapitalMedical University Beijing 100029 China

The pulmonary veins have been demonstrated to be the major source of atrial fibrillation （AF）. Isolation of the pulmonary veins is effective in curing patients with paroxysmal AE However, this strategy is associated with limited success in some patients with paroxysmal AF and in most patients with persistent and permanent AF It requires more widespread ablation targeting most parts of the left atrial and thoracic veins and may include some discrete sites, which, if missed or neglected, can lead to persistence of fibrillation. In recent years, other AF origins have also been reported in addition to some types of atrial tachycardia and AF originating from the coronary sinus （CS） musculature. The CS appears to be a major element perpetuating persistent AF.

关键词： coronary sinus atrial fibrillation catheter ablation

Investigations on High-Speed Flash Boiling Atomization of Fuel Based on Numerical Simulations

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Computer Modeling in Engineering & Sciences 2024年第5期139卷 1427-1453页

作者： Wei zhong Zhenfang xin Lihua Wang Haiping liu School of Aerospace Engineering and Applied Mechanics Tongji UniversityShanghai200092China Beijing Mechanical Equipment Research Institute Beijing100854China

Flash boiling atomization(FBA)is a promising approach for enhancing spray atomization,which can generate a fine and more evenly distributed spray by increasing the fuel injection temperature or reducing the ambient ***,when the outlet speed of the nozzle exceeds 400 m/s,investigating high-speed flash boiling atomization(HFBA)becomes quite *** difficulty arises fromthe involvement ofmany complex physical processes and the requirement for a very fine mesh in numerical *** this study,an HFBA model for gasoline direct injection(GDI)is *** model incorporates primary and secondary atomization,as well as vaporization and boilingmodels,to describe the development process of the flash boiling *** to lowspeed FBA,these physical processes significantly impact *** this model,the Eulerian description is utilized for modeling the gas,and the Lagrangian description is applied to model the droplets,which effectively captures the movement of the droplets and avoids excessive mesh in the Eulerian *** various conditions,numerical solutions of the Sauter mean diameter(SMD)for GDI show good agreement with experimental data,validating the proposed model’s *** based on this HFBA model investigate the influences of fuel injection temperature and ambient pressure on the atomization *** analyses of the velocity field,temperature field,vapor mass fraction distribution,particle size distribution,and spray penetration length under different superheat degrees reveal that high injection temperature or low ambient pressure significantly affects the formation of small and dispersed droplet *** effect is conducive to the refinement of spray particles and enhances atomization.

关键词： High-speed flash boiling atomization numerical simulations Eulerian description Lagrangian description gasoline direct injection

Paramagnetism and improved upconversion luminescence properties of NaYF4：Yb,Er/NaGdF4 nanocomposites synthesized by a boiling water seed-mediated route

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Frontiers of Materials Science 2016年第1期10卷 38-44页

作者： Chao-Qing YANG Ao-Ju LI Wei GUO Peng-Hua TIAN Xiao-Long YU zhong-xin liu Yang CAO zhong-Liang SUN Key Laboratory of Ministry of Education for Advanced Materials in Tropical Island Resources Hainan University Haikou 570228 China

In a route boiling water served as reaction medium, a stoichiometric amount of rare-earth compound and fluoride are put into this system to form a-NaYF4：Yb, Er nuclei. Then prepared sample is heated at elevated temperature to improve the fluorescence intensity, and next a NaGdF4 shell grows on the surface of NaYF4 nuclei. NaYF4：Yb,ErlNaGdF4 core-shell structured upconversion nanoparticles （CSUCNPs） have been successfully synthesized by above route. The use of boiling water decreases the cubic-to-hexagonal phase transition temperature of NaYF4：Yb,Er to 350℃ and increases its upconversion （UC） luminescence intensity. A heterogeneous NaGdF4 epitaxially growing on the surface of Ln^3＋-doped NaYF4 not only improves UC luminescence, but also creates a paramagnetic shell, which can be used as contrast agents in magnetic resonance imaging （MRI）o The solution of CSUCNPs shows bright green UC fluorescence under the excitation at 980 nm in a power density only about 50 ***-2. A broad spectrum with a dominant resonance at g of about 2 is observed by the electron paramagnetic resonance （EPR） spectrum of CSUCNPs. Above properties suggest that the obtained CSUCNPs could be potential candidates for dual-mode optical/magnetic bioapplications.

关键词： boiling water upconversion nanoparticle fluorescence imaging paramagnetism