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Nonlinear distortion and spatial dispersion of intense terahertz generation in lithium niobate via the tilted pulse front technique

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Photonics Research 2018年第10期6卷 959-964页

作者： BAOLONG ZHANG SHANGQING LI SHUSU CHAI XIAOJUN Wu jinglong ma LIMING CHEN YUTONG LI Beijing National Laboratory for Condensed matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China School of Physical Sciences University of Chinese Academy of Sciences Beijing 100049 China School of Electronic and Information Engineering Beihang University Beijing 100191 China Collaborative Innovation Center of IFSA (CICIFSA) Shanghai Jiao Tong University Shanghai 200240 China

We systematically investigate the influences of the input infrared spectrum, chirp, and polarization on the emitted intense terahertz spectrum and spatial dispersion in lithium niobate via optical rectification. The terahertz yield and emission spectrum depend on both the chirp and spectrum of the input pump laser pulses. We also observe slight non-uniform spatial dispersion using a knife-edge measurement, which agrees well with the original predictions. The possible mechanism is the nonlinear distortion effect caused by high-energy laser *** study is very important and useful for developing intense terahertz systems with applications in extreme terahertz sciences and nonlinear phenomena.

关键词：红外光谱激光技术发展现状通讯技术

Polarization of terahertz emission out of incident plane from laser interactions with solid targets

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Science China(Physics,Mechanics & Astronomy) 2012年第4期55卷 589-592页

作者： DU Fei LI Chun ZHOU MuLin WANG WeiMin SU LuNing ZHENG Yi LI YuTong ma jinglong SHENG ZhengMing CHEN LiMing LU Xin WANG ZhaoHua WEI ZhiYi ZHANG Jie Beijing National Laboratory of Condensed matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China Key Laboratory for Laser Plasmas （Ministry of Education） and Department of Physics Shanghai Jiao Tong University Shanghai 200240 China

A powerful terahertz(THz) pulse was produced by a p-polarized,70 fs,800 nm laser interacting with solid targets at an incident angle of 45°.The polarization of the THz emission was measured out of the laser incident *** results showed that it was linearly *** established a surface current model to explain this phenomenon,assuming that the transient current moving along the plasma surface was responsible for the generation of the THz *** model expectation and the experimental result were in good agreement.

关键词： terahertz emission laser solid interactions polarization

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成人慢性骨髓炎的临床诊断和治疗进展

中国修复重建外科杂志 2020年第5期34卷 651-655页

作者：马敬龙阳富春广西医科大学第一附属医院创伤骨科手外科南宁530021

目的对成人慢性骨髓炎的临床诊断和治疗进展进行综述。方法广泛查阅近年与成人慢性骨髓炎相关的文献,对其临床诊断和治疗方法进行归纳总结。结果临床特征和实验室检查可协助诊断成人慢性骨髓炎,病原学检查结果是选择抗生素的依据,影像... 详细信息

目的对成人慢性骨髓炎的临床诊断和治疗进展进行综述。方法广泛查阅近年与成人慢性骨髓炎相关的文献,对其临床诊断和治疗方法进行归纳总结。结果临床特征和实验室检查可协助诊断成人慢性骨髓炎,病原学检查结果是选择抗生素的依据,影像学检查具有特异性。治疗方式包括全身治疗和局部治疗,其中局部治疗是根治的关键。结论成人慢性骨髓炎应早期诊断,根据患者解剖和生理分型制定合适的治疗方案。

关键词：成人慢性骨髓炎诊断治疗

The influence of target material and thickness on proton energy and angular distribution

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Science China(Physics,Mechanics & Astronomy) 2013年第2期56卷 457-461页

作者： SU LuNing LIU BiCheng LIN XiaoXuan LIU Feng DU Fei LIU XiaoLong ZHENG Yi GE XuLei LI YuTong SHENG ZhengMing CHEN LiMing WANG WeiMin ma jinglong LU Xin WEI ZhiYi CHEN JiaEr ZHANG Jie Beijing National Laboratory for Condensed matter Physics Institute of PhysicsChinese Academy of Sciences State Key Laboratory of Nuclear Physics and Technology Institute of Heavy Ion PhysicsPeking University Key Laboratory for Laser Plasmas(Ministry of Education) and Department of Physics Shanghai Jiao Tong University

The paper has studied the influence of target material and thickness on energy and angular distributions of the protons generated by using an 800 rim, 60 fs, 0.24 J laser pulse to irradiate solid target foils. The results show that the initial density and thickness of the targets will affect the formation of the acceleration sheath fields in the target normal direction. For the same target thickness, using lower density target materials can obtain a higher proton maximum energy. However, lower density targets tend to be deformed due to the shock waves launched by the laser pulses, making the proton spatial distribution more divergent.

关键词： laser-driven proton acceleration

Proton angular distribution research by a new angle-resolved proton energy spectrometer

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Science China(Physics,Mechanics & Astronomy) 2014年第5期57卷 844-848页

作者： SU LuNing ZHENG Yi LIU Meng HU ZhiDan WANG WeiMin YUAN XiaoHui XU MiaoHua SHENG ZhengMing SHEN ZhongWei FAN HaiTao LI YuTong ma jinglong LU Xin CHEN LiMing WANG ZhaoHua WEI ZhiYi ZHANG Jie Beijing National Laboratory for Condensed matter Physics Institute of PhysicsChinese Academy of Sciences Key Laboratory for Laser Plasmas (MoE) and Department of Physics Shanghai Jiao Tong University Department of Physics China University of Mining and Technology (Beijing)

The proton spectral and angular distributions simultaneously within the target normal direction and laser propagation direction by using an angle-resolved proton energy spectrometer are *** the protons generated in the interactions of 100 fs,800nm laser pulses with aluminum foil targets,the deviations of proton beam centers of different energies from the target normal direction towards the laser propagation direction are *** is probably because of the toroidal magnetic fields generated at the rear target surface,which deflect protons *** a result,protons in low energy range have large deviation angles,protons in middle energy range have the smallest deviation angles,while protons in high energy tail have large deviation angles.

关键词： laser-driven proton acceleration

Double-slit diffraction of terahertz wave generated by tilted-pulse-front pumping

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Chinese Optics Letters 2021年第5期19卷 60-64页

作者： Shangqing Li jinglong ma Xiaojun Wu Baolong Zhang Chen Ouyang Tianze Wang Dan Wang Xuan Wang Yutong Li Beijing National Laboratory for Condensed matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China School of Electronic and Information Engineering Beihang UniversityBeijing 100191China Songshan Lake materials Laboratory Dongguan 523808China CAS Center for Excellence in Ultra-intense Laser Science Shanghai 201800China

We propose a spatial diffraction diagnostic method via inserting a millimeter-gap double slit into the collimated terahertz beam to monitor the minute variation of the terahertz beam in strong-field terahertz sources,which is difficult to be resolved in conventional terahertz imaging *** verify the method,we intentionally fabricate tiny variations of the terahertz beam through tuning the iris for the infrared pumping beam before the tilted-pulse-front pumping *** phenomena can be well explained by the theory based on the tilted-pulse-front technique and terahertz diffraction.

关键词： spatial diffraction diagnostic method strong-field terahertz sources tilted-pulse-front pumping terahertz diffraction

Transmission Degradation of Femtosecond Laser Pulses in Opened Cone Targets

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Plasma Science and Technology 2012年第1期14卷 24-27页

作者： LIU Feng LIN Xiaoxuan LIU Bicheng DING Wenjun DU Fei LI Yutong ma jinglong LIU Xiaolong SHENG Zhengming CHEN Liming LU Xin DONG Quanli WANG Weimin WANG Zhaohua WEI Zhiyi CHEN Jiaer ZHANG Jie Institute of Physics Chinese Academy of SciencesBeijing 100190China Key Laboratory for Laser Plasmas(MoE)and Department of Physics Shanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Nuclear Physics and Technology Institute of Heavy Ion PhysicsPeking UniversityBeijing 100871China

Irradiated by femtosecond laser pulses with different energies, opened cone targets behave very differently in the transmission of incident laser pulses. The targets, each with an opening angle of 71° and an opening of 5 μm, are fabricated using standard semiconductor technology. When the incident laser energy is low and no pre-plasma is generated on the side walls of the cones, the cone target acts like an optical device to reflect the laser pulse, and 15% of the laser energy can be transmitted through the cones. In contrast, when the incident laser energy is high enough to generate pre-plasmas by the pre-pulse of the main pulse that fills the inner cone, the cone with the plasmas will block the transmission of the laser, which leads to a decrease in laser transmission compared with the low-energy case with no plasma. Simulation results using optical software in the low-energy case, and using the particle-in-cell code in the high-energy case, are primarily in agreement with the experimental results.

关键词： femtosecond laser pulse cone target transmission ratio

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基于滑转条件下的履带车辆原地转向特性研究

农机化研究 2013年第2期35卷 240-243页

作者：罗恩志冯江张敏马静龙东北农业大学工程学院哈尔滨150030

在考虑履带滑转的基础上,建立了履带车辆原地转向时的数学模型,并进行相关的运动学和动力学分析,推导出履带实际转向速度、转向角速度和滑转率的表达式均与横向偏移量S有关。列出动力学平衡方程,运用matlab软件计算出横向偏移量S值。结... 详细信息

在考虑履带滑转的基础上,建立了履带车辆原地转向时的数学模型,并进行相关的运动学和动力学分析,推导出履带实际转向速度、转向角速度和滑转率的表达式均与横向偏移量S有关。列出动力学平衡方程,运用matlab软件计算出横向偏移量S值。结果表明:在已知履带车辆结构参数λ为定值时,履带原地转向时相对应的横向偏移量S随地面参数f/μ的增大而增大;考虑履带滑转情况下的履带转向角速度是未考虑时结果的65.3%;选取不同地面参数对应的横向偏移量S在0.3～0.5之间变化时,履带车辆滑转率为30.8%～42.6%;机车主要参数已知时,对应的转向阻力矩约是传统算法下转向阻力矩的1.26倍。

关键词：履带车辆原地转向横向偏移量滑转

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一种关节型摆盘机械手的运动学分析

农机化研究 2014年第8期36卷 14-18页

作者：马静龙冯江张敏于立宝东北农业大学工程学院哈尔滨150030 东北农业大学电气与信息学院哈尔滨150030

为解决目前水稻育秧摆盘作业仍以人工为主、种植季节需要大量劳动力、劳动强度大、作业效率低等问题,设计了一种4自由度关节型机械手实现摆盘作业,对机械手的手臂和手腕进行选型。运用D-H方法构建了机械手的运动学模型,利用maTLAB强大... 详细信息

为解决目前水稻育秧摆盘作业仍以人工为主、种植季节需要大量劳动力、劳动强度大、作业效率低等问题,设计了一种4自由度关节型机械手实现摆盘作业,对机械手的手臂和手腕进行选型。运用D-H方法构建了机械手的运动学模型,利用maTLAB强大的符号运算功能对方程进行求解,得出正逆运动学的解。通过正逆运动学的解,可以得出机械手各关节工作时的运动轨迹和机械手欲到达某一位姿时各关节的扭角值。

关键词：机械手秧盘摆放运动学分析