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Evolution of finite energy Airy beams in cubic-quintic atomic vapor system

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Frontiers of physics 2018年第1期13卷 143-151页

作者： zhen-kun wu Hao Guo Wei Wang Yu-Zong Gu Institute of Microsystem Physics School of Physics and Electronics Henan University Kaifeng 475004 China Key Laboratory for Physical Electronics and Devices of the Ministry of Education The School of Electronic and Information Engineering Xi'an Jiaotong University Xi'an 710049 China

In a numerical investigation, we demonstrate the evolution of a one-dimensional and two-dimensional finite energy Airy beam in a A-type three-level atomic vapor with linear, cubic, and quintic susceptibilities considered simultaneously with the dressing effect. Quasi-solitons and soliton pairs are observed due to this competition mechanism. We find that the frequency detuning of the pump field and its power greatly affect the formation and evolution of generated solitons. In general, around the two- photon resonance point, and for low intensities of the pump field, it is less difficult to form solitons. This investigation enriches the study of the propagation properties of Airy beams and soliton generation in atomic vapor.

关键词： airy beam cubic-quintic nonlinear soliton atomic vapor system

Talbot effect in nonparaxial self- accelerating beams with electromagnetically induced transparency

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Frontiers of physics 2020年第5期15卷 137-143页

作者： Jing-Min Ru zhen-kun wu Ya-Gang Zhang Feng Wen Yu-Zong Gu Institute of Nano/Photon Materials and Application School of Physics and ElectronicsHenan UniversityKaifeng 475004China National Demonstmtion Center for Experimental Physics and Electronics Education School of Physics and ElectronicsHenan UniversityKaifeng 475004China Key Laboratory for Physical Electronics and Devices of the Ministry of Education&School of Science&Shaanxi Key Lab of Information Photonic Technique&Institute of Wide Bandqap Semiconductors Xi'an Jiaotonq UniversityXi'an 710049China

In this study,we report on the fractional Talbot ffect of nonpar axial self-accelerating beams in a multilevel electromagnetically induced transparency(EIT)atomic configuration,which,to the best of our knowledge,is the first study on this subject.The Tallbot ffect originates from superposed eigenmodes of the Helmholtz equation and forms in the EIT window in the presence of both linear and cubic susceptibilities.The Talbot ffect can be realized by appropriately selecting the cofficients of the beam components.Our results indicate that the larger the radial difference between beam components,the stronger the interference between them,the smaller the Tallbot angle is.The results of this study can be useful when studying optical imaging.optical measurements,and optical computing.

关键词： multilevel atomic configuration nonparaxial self-accelerating beam Talbot effect electromagnetically induced transparency

Coherent control of dressed images of four-wave mixing

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Frontiers of physics 2013年第2期8卷 228-235页

作者： zhen-kun wu Yi-Qi Zhang Tai-kun Liu Zhao-Yang Zhang Cheng Li Yan-Peng Zhang Min Xiao Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique Xi ' an Jiaotong UniversityChina Xi 'an 710049 Department of Physics University of Arkansas FayettevilleUSA Arkansas 72701 National Laboratory of Solid State Microstructures and Department of Physics Nanjing UniversityChina Nanjing 210093

在里面象 V 类型三水平的原子系统一样二水平，我们学习探查传播，四波浪的混合(FWM ) 并且有调味品的荧光信号试验性地并且理论上完成。我们发现两个 hyperfine 结构(在一样的精力水平) 并且转变偶极子时刻(在不同精力层次) 能影响穿... 详细信息

在里面象 V 类型三水平的原子系统一样二水平，我们学习探查传播，四波浪的混合(FWM ) 并且有调味品的荧光信号试验性地并且理论上完成。我们发现两个 hyperfine 结构(在一样的精力水平) 并且转变偶极子时刻(在不同精力层次) 能影响穿衣的效果。我们试验性地也在二水平的原子系统在探查和产生 FWM 的图象的非线性的繁殖调查那角度控制动力学，并且发现集中并且散焦探查横梁和 FWM 信号能被在处理领域之间的角度极大地影响。

关键词：四波混频相干控制图像三能级原子系统荧光信号能量水平跃迁偶极矩超精细结构

Modulation of four-wave mixing via photonic band gap

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Frontiers of physics 2014年第5期9卷 665-670页

作者： zhen-kun wu Kai-Ge Chang Yi Hu Yun-Zhe Zhang Zi-Hai Jiang Yan-Peng Zhang Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique and School of Science Xi'an Jiaotong University Xi'an 710049 China Education Institute of Taiyuan University Taiyuan 030001 China Institute of Applied Physics Xi'an University of Arts and Science Xi'an 710065 China

处理四波浪的混合(FWM ) 在里面一四水平 85 Rb 原子系统，试验性地在这篇论文示威了，被二共存过程包括。一个人是排放信号由于提高经由电磁地导致的透明性(EIT ) 非线性。因为创造 photonic 乐队差距(PBG ) ，其它是探查横梁的布拉... 详细信息

处理四波浪的混合(FWM ) 在里面一四水平 85 Rb 原子系统，试验性地在这篇论文示威了，被二共存过程包括。一个人是排放信号由于提高经由电磁地导致的透明性(EIT ) 非线性。因为创造 photonic 乐队差距(PBG ) ，其它是探查横梁的布拉格思考，它被线性、第三顺序的非线性的危险性影响。而且，我们证明了不同试验性的参数能显著地与灵活地控制的 PBG 影响测量信号。这些研究为在产生 FWM 处理理解基本机制被发现有用。

关键词：四波混频光子带隙调制电磁感应透明发射信号强非线性实验参数布拉格反射

Hippocampal dopamine as a key regulator for learning deficits in Parkinson's disease

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Neural Regeneration Research 2024年第6期19卷 1193-1194页

作者： kun wu Shuai Liu Shanghai Key Laboratory of Brain Functional Genomics (Ministry of Education) Affiliated Mental Health Center (ECNU) School of Psychology and Cognitive Science East China Normal University Shanghai Changning Mental Health Center NYU-ECNU Institute of Brain and Cognitive Science at NYU Shanghai

Parkinson’s disease(PD) is a progressive neurodegenerative disorder with clinical symptoms of involuntary or uncontrollable movements such as tremors,rigidity,and incoordination.The learning deficit is largely overlo... 详细信息

关键词： MEMORY

Prognostic value of circulating tumor cells combined with neutrophil-lymphocyte ratio in patients with hepatocellular carcinoma

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World Journal of Gastrointestinal Oncology 2024年第2期16卷 372-385页

作者： Jia-Li Chen Lu Guo zhen-Ying wu kun He Han Li Chi Yang Yun-Wei Han Department of Oncology The Affiliated Hospital of Southwest Medical UniversityLuzhou 646000Sichuan ProvinceChina Department of Ophthalmology The Affiliated Hospital of Southwest Medical UniversityLuzhou 646000Sichuan ProvinceChina Clinical Research Institute The Affiliated Hospital of Southwest Medical UniversityLuzhou 646000Sichuan ProvinceChina Department of Plastic Surgery Meguiar's Medical Beauty HospitalChengdu 610000Sichuan ProvinceChina

BACKGROUND Circulating tumor cell(CTC)count and neutrophil-to-lymphocyte ratio(NLR)are both closely associated with the prognosis of hepatocellular carcinoma(HCC).AIM To investigate the prognostic value of combining these two indicators in HCC.METHODS Clinical data were collected from patients with advanced HCC who received im-mune therapy combined with targeted therapy at the Department of Oncology,the Affiliated Hospital of Southwest Medical University,Sichuan,China,from 2021 to 2023.The optimal cutoff values for CTC programmed death-ligand 1(PD-L1)(+)>1 or CTC PD-L1(+)≤1 and NLR>3.89 or NLR≤3.89 were evaluated using X-Tile software.Patients were categorized into three groups based on CTC PD-L1(+)counts and NLR:CTC-NLR(0),CTC-NLR(1),and CTC-NLR(2).The relationship between CTC-NLR and clinical variables as well as survival rates was assessed.RESULTS Patients with high CTC PD-L1(+)expression or NLR at baseline had shorter median progression-free survival(m-PFS)and median overall survival(mOS)than those with low levels of CTC PD-L1(+)or NLR(P<0.001).Mean-while,patients in the CTC-NLR(2)group showed a significant decrease in mPFS and mOS.Cox regression analysis revealed that alpha-fetoprotein(AFP),CTC PD-L1(+),and CTC-NLR were independent predictors of OS.The time-dependent receiver operating characteristic curve showed that the area under the curve of CTC-NLR at 12 months(0.821)and 18 months(0.821)was superior to that of AFP and CTC PD-L1(+).CONCLUSION HCC patients with high CTC PD-L1(+)or NLR expression tend to exhibit poor prognosis,and a high baseline CTC-NLR score may indicate low survival.CTC-NLR may serve as an effective prognostic indicator for patients with advanced HCC receiving immunotherapy combined with targeted therapy.

关键词： Circulating tumor cells Neutrophil–lymphocyte ratio Hepatocellular carcinoma Prognosis Survival Marker

Flow instability of supercritical hydrocarbon fuel in a multi-channel cooling system

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Chinese Journal of Aeronautics 2024年第2期37卷 283-295页

作者： Yichao JIN kun wu Xuejun FAN Institute of Applied Physics and Computational Mathematics Beijing 100094China Institute of Mechanics Chinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China

Thermally-induced flow instabilities are a critical issue in multi-channel regenerative cooling systems.In particular,the interactions between Density-Wave Oscillations(DWO)and Flow Maldistribution(FMD)can result in complex and disastrous instability phenomena.This study investigates the instability behaviors of hydrocarbon fluid in a four-channel system with a constant heat flux ratio using both frequency-and time-domain methods.As the heat flux increases,the in-tube flow sequentially destabilizes in each channel and converges to new equilibrium states,leading to the emergence of FMD phenomena.This also causes the system eigenvalue to change repeatedly from negative to positive rather than increasing monotonically.Additionally,the system eigenvalues are between those of the two most unstable channels,indicating that the stability behavior of the entire system is dictated by the most unstable channel.After FMD occurs,flow oscillations are activated in channels with weak stability,and the in-tube flow is observed to evolve into various flow patterns,including stable flow,self-sustained oscillation,oscillation divergence,quasiperiodic oscillation,and oscillation excursion.The novel instability mode of oscillation excursion involves a spontaneous transition of operating states.It oscillates from an equilibrium state and then stabilizes at a new operational state after oscillation-induced redistribution.However,the newfound stable state may also be only temporary,with the in-tube flow regressing to the initial state,resulting in quasi-periodic oscillation.

关键词： Cooling Supercritical fluids Hydrocarbons Flow instability Flow maldistribution Density-wave oscillations

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Pollution characteristics and source apportionment of heavy metal(loid)s in soil and groundwater of a retired industrial park

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Journal of Environmental Sciences 2024年第9期143卷 23-34页

作者： Zijing Xiang Shijin wu Lizhong Zhu kun Yang Daohui Lin Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control Department of Environmental SciencesZhejiang UniversityHangzhou 310058China Zhejiang Ecological Civilization Academy Anji 313300China

Heavy metal(loid)s(HMs)pollution has become a common and complex problem in industrial parks due to rapid industrialization and urbanization.Here,soil and groundwater were sampled from a retired industrial park to investigate the pollution characteristics of HMs.Results show that Ni,Pb,Cr,Zn,Cd,and Cu were the typical HMs in the soil.Source analysis with the positive matrix factorization model indicates that HMs in the topsoil stemmed from industrial activities,traffic emission,and natural source,and the groundwater HMs originated from industrial activities,groundwater-soil interaction,groundwater-rock interaction,and atmosphere deposition.The sequential extraction of soil HMs reveals that As and Hg were mainly distributed in the residue fraction,while Ni,Pb,Cr,Zn,Cd,and Cu mainly existed in the mobile fraction.Most HMs either in the total concentration or in the bioavailable fraction preferred to retain in soil as indicated by their high soil-water partitioning coefficients(K_(d)),and the K_(d) values were correlated with soil pH,groundwater redox potential,and dissolved oxygen.The relative stable soil-groundwater circumstance and the low active fraction contents limited the vertical migration of soil HMs and their release to groundwater.These findings increase our knowledge about HMs pollution characteristics of traditional industrial parks and provide a protocol for HMs pollution scrutinizing in large zones.

关键词： Heavy metal(loid)s Industrial park Source apportionment Chemical fraction Soil-groundwater partitioning

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Investigation of high rate mechanical flow followed by ignition for high-energy propellant under dynamic extrusion loading

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Defence Technology（防务技术） 2024年第2期32卷 336-347页

作者： Liying Dong Yanqing wu kun Yang Xiao Hou State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China

Investigating the ignition response of nitrate ester plasticized polyether(NEPE) propellant under dynamic extrusion loading is of great significant at least for two cases. Firstly, it helps to understand the mechanism and conditions of unwanted ignition inside charged propellant under accident stimulus.Secondly, evaluates the risk of a shell crevice in a solid rocket motor(SRM) under a falling or overturning scene. In the present study, an innovative visual crevice extrusion experiment is designed using a dropweight apparatus. The dynamic responses of NEPE propellant during extrusion loading, including compaction and compression, rapid shear flow into the crevice, stress concentration, and ignition reaction, have been firstly observed using a high-performance high-speed camera. The ignition reaction is observed in the triangular region of the NEPE propellant sample above the crevice when the drop weight velocity was 1.90 m/s. Based on the user material subroutine interface UMAT provided by finite element software LS-DYNA, a viscoelastic-plastic model and dual ignition criterion related to plastic shear dissipation are developed and applied to the local ignition response analysis under crevice extrusion conditions. The stress concentration occurs in the crevice location of the propellant sample, the shear stress is relatively large, the effective plastic work is relatively large, and the ignition reaction is easy to occur. When the sample thickness decreases from 5 mm to 2.5 mm, the shear stress increases from 22.3 MPa to 28.6 MPa, the critical value of effective plastic work required for ignition is shortened from 1280 μs to 730 μs, and the triangular area is easily triggering an ignition reaction. The propellant sample with a small thickness is more likely to stress concentration, resulting in large shear stress and effective work, triggering an ignition reaction.

关键词： NEPE propellant Crevice extrusion Shear flow Sample thickness Ignition reaction

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