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Sensitivity Improvements for Picosecond Ultrasonic Thickness Measurements in Gold and Tungsten Nanoscale Films

Nanomanufacturing and Metrology 2024年第2期7卷 1-12页

作者： Jiaqi Dong Chengyuan Yao Yuanhao Zhu Shaojie Li Bowen Liu jintao fan Chunguang Hu Youjian Song Minglie Hu Key Laboratory of Opto-Electronic Information Science and Technology of Ministry of Education School of Precision Instruments and Opto-Electronics EngineeringTianjin UniversityTianjin 300072China State Key Laboratory of Precision Measuring Technology and Instruments Tianjin UniversityTianjin 300072China

Picosecond ultrasonics,as a nondestructive and noncontact method,can be employed for nanoscale metallic film thickness *** sensitivity of the system,which determines the measurement precision and practicability of this technique,is often limited by the weak intensity of the ultrasonic *** solve this problem,we investigate the distinct mechanisms involved in picosecond ultrasonic thickness measurement for two types of metals,namely tungsten(W)and gold(Au).For thickness measurement in W films,theory and simulation show that optimizing the pump and probe laser wavelengths,which determine the intensity and shape of the ultrasonic signal,is critical to improving measurement sensitivity,while for Au film measurements,where acoustic-induced beam distortion is dominant,the signal intensity can be optimized by selecting an appropriate aperture size and sample *** above approaches are validated in experiments.A dual-wavelength pump-probe system is constructed based on a passively mode-locked ytterbium-doped fiber *** smoothing method and multipeak Gaussian fitting are employed for the extraction of ultrasonic *** measurement precision is achieved in a series of W and Au films with thicknesses of 43-750 *** work can be applied to various high-precision,noncontact measurements of metal film thickness in the semiconductor industry.

关键词： Picosecond ultrasonics Thickness measurement Optical pump-probe Beam distortion technique

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电磁场对铝合金组织及性能影响的研究进展

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金属热处理 2024年第6期49卷 261-270页

作者：钟振东樊金桃王付胜陈亚军中国民航大学中欧航空工程师学院天津300300 天津市紧固连接技术企业重点实验室天津300300 航天精工股份有限公司天津300300

归纳了铝合金的电磁场处理工艺,并从微观组织、宏观性能及作用机理三个层面分析了电磁场处理工艺对铝合金组织性能的影响,总结出电磁场处理工艺参数选择的影响因素,揭示出电磁场对铝合金组织及性能优化的作用机理,并在最后探讨了未来电... 详细信息

归纳了铝合金的电磁场处理工艺,并从微观组织、宏观性能及作用机理三个层面分析了电磁场处理工艺对铝合金组织性能的影响,总结出电磁场处理工艺参数选择的影响因素,揭示出电磁场对铝合金组织及性能优化的作用机理,并在最后探讨了未来电磁场处理工艺研究的重点和方向。

关键词：铝合金电磁场微观组织性能机理

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Multi-mechanism Orogenic Model of the Su-Jiao Orogenic Belt

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Acta Geologica Sinica(English Edition) 2000年第2期74卷 201-206页

作者： fan jintao CHEN Jiongda CHEN Huogen Geological Survey of Jiangsu Province Nanjing 211135Jianesu

The Su-Jiao orogenic belt is the eastern part of the Central Mountain System of China. Recent studies on its orogenic system indicate that the Su-Jiao orogenic belt is a complex orogenic belt which suffered at least 3 orogenies of different mechanisms in the Mesoproterozoic, Neoproterozoic and Triassic respectively. The Meso-Neoproterozoic orogenies belong to the Wilson cycle on the plate margins. The belt is a part of the Late Mesoproterozoic supercontinent Rodinia. The Triassic orogeny belongs to the re-orogeny of the non-Wilson cycle. Delamination of mountain roots occurred after both the Wilson and non-Wilson cycles in the Su-Jiao orogenic belt. The large-amplitude isostatic uplift of mountains, magmatic activities and basin-forming and mountain-making in the upper crust, all indicate the general significance of delamination in the development of orogenic belts.

关键词： orogenic system multi-mechanism re-orogeny Su-Jiao orogenic belt

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水淬锰渣-炉渣-石灰石复合微粉的活性试验

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桂林理工大学学报 2024年第1期44卷 149-154页

作者：樊金涛刘荣进陈平张建兵唐小春李伦君桂林理工大学材料科学与工程学院广西桂林541004 桂林理工大学广西工业废渣建材资源利用工程技术研究中心广西桂林541004 桂林理工大学广西壮族自治区北部湾绿色海工材料工程研究中心广西桂林541004 北京金隅砂浆有限公司北京102402 广西鱼峰集团有限公司广西柳州545008 铜仁市万山区建辉新型环保建材有限公司贵州铜仁554202

研究了经过物理激发的水淬锰渣微粉和炉渣微粉活性指数,进而确定水淬锰渣、炉渣适宜的比表面积;采用石膏、生石灰、水玻璃3种激发剂对水淬锰渣、炉渣、石灰石复合微粉进行了化学激发试验;探讨单一激发和复合激发对复合微粉的影响。结果... 详细信息

研究了经过物理激发的水淬锰渣微粉和炉渣微粉活性指数,进而确定水淬锰渣、炉渣适宜的比表面积;采用石膏、生石灰、水玻璃3种激发剂对水淬锰渣、炉渣、石灰石复合微粉进行了化学激发试验;探讨单一激发和复合激发对复合微粉的影响。结果表明:物理激发微粉时,水淬锰渣的适宜比表面积为470 m^(2)/kg,炉渣的适宜比表面积为410 m^(2)/kg;化学激发复合微粉时,使用4%的石膏和1%生石灰作为复合激发剂对复合微粉激发效果最佳,7、28 d活性指数达到最高,此时复合微粉7 d活性指数为55.7%,28 d活性指数为78.3%,均满足《用于水泥、砂浆和混凝土中的粒化高炉矿渣粉》(GB/T 18046—2017)中S75等级标准。

关键词：水淬锰渣炉渣复合微粉活性激发活性指数

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Dissipative Kerr solitons in optical microresonators with Raman effect and third-order dispersion

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Chinese Physics B 2021年第5期30卷 395-400页

作者： Chaohua Wu Zhiwei fang jintao fan Gang Chen Ya Cheng State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Laser SpectroscopyShanxi UniversityTaiyuan 030006China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China The Extreme Optoelectromechanics Laboratory(XXL) School of Physics and Materials ScienceEast China Normal UniversityShanghai 200241China Collaborative Innovation Center of Light Manipulations and Applications Shandong Normal UniversityJinan 250358China

Using the mean-field normalized Lugiato-Lefever equation,we theoretically investigate the dynamics of cavity soliton and comb generation in the presence of Raman effect and the third-order *** of them can induce the temporal drift and frequency *** on the moment analysis method,we analytically obtain the temporal and frequency shift,and the results agree with the direct numerical ***,the compensation and enhancement of the soliton spectral between the Raman-induced self-frequency shift and soliton recoil are *** results pave the way for further understanding the soliton dynamics and spectral characteristics,and providing an effective route to manipulate frequency comb.

关键词： dissipative Kerr soliton frequency comb Raman effect dispersive wave

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基于人工智能技术的雨量校准故障诊断与预警辅助系统研究

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软件 2024年第5期45卷 165-168页

作者：孟超刘名张二国樊锦涛郭少杰陕西省大气探测技术保障中心陕西西安710014 陕西省气象局秦岭和黄土高原生态环境气象重点实验室陕西西安710016

基于人工智能技术的雨量校准故障诊断与预警辅助系统,通过气象观测数据“云”获取设备计量数据进行预处理,采用多种数据驱动和人工智能算法,利用深度学习及神经网络,对采集的数据进行分析,对数据样本进行训练学习,诊断设备是否存在故障... 详细信息

基于人工智能技术的雨量校准故障诊断与预警辅助系统,通过气象观测数据“云”获取设备计量数据进行预处理,采用多种数据驱动和人工智能算法,利用深度学习及神经网络,对采集的数据进行分析,对数据样本进行训练学习,诊断设备是否存在故障并对设备存在的风险进行预警判断。采用神经网络分析设备故障,根据分析出的设备故障情况,系统以大数据为核心、智能算法为底层逻辑模式分析并推送解决方案,有效地提升了户外计量工作效能,对气象自动站其他高精度传感器检定、校准的多源数据分析和诊断具有较好的开拓意义。

关键词：人工智能雨量校准故障诊断预警辅助

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Slope-climbing of cropland and its effects in China

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Journal of Mountain Science 2024年第8期21卷 2754-2769页

作者： CHEN Wanxu XIE Youping YUAN jintao ZENG Jie YANG Liyan GU Tianci LEI fan Hubei Key Laboratory of Regional Ecology and Environmental Change School of Geography and Information EngineeringChina University of GeosciencesWuhan 430074China Key Laboratory of Natural Resources Monitoring and Supervision in Southern Hilly Region Ministry of Natural ResourcesChangsha 410118China Yunnan Key Laboratory of Plateau Geographic Processes and Environmental Changes Faculty of GeographyYunnan Normal UniversityKunming 650500China

In recent decades,the spatio-temporal patterns of China’s croplands have been reshaped by disturbances from anthropogenic activities,with complex changes in the topographic characteristics of ***-climbing of croplands(SCCL)is an important issue that threatens sustainable agricultural *** providing land with prominent location advantages,SCCL weakens the water and fertilizer retention capacity for cropland,intensifies various geological disasters,and adversely affects the ecological environment and food yield of these *** is crucial to determine the spatio-temporal variation features and effects of SCCL in China to formulate more accurate cropland protection policies and to maintain food security;however,the current lack of relevant studies is detrimental for capturing trends in cropland resources and sustainable cropland *** this study,we constructed a multi-scale slope spectrum for cropland and total terrain to explore the spatial differences and trends of SCCL from a three-dimensional *** evaluated the natural and socioeconomic effects of SCCL in China from multiple *** indicate that the proportion of cropland with slopes below 2°,5°,and 6°in China decreased by 0.43%,0.47%,and 0.50%from 1980 to 2020,*** became apparent during 1980-1990 and 2010-2020,especially over the recent *** cropland climbing index(CCI)and upper limited slope change(ULSC)to measure the spatio-temporal pattern of SCCL were 0.99%and 1.17°,respectively,during *** the agricultural regional scale,the SCCL was also concentrated in 1980-1990 and 2010-2020,and it is more pronounced in the southern *** proportion of provinces and prefecture-level cities with high-intensity SCCL during 1980-2020 were 87.10%and 49.73%,*** was comparatively more pronounced and broader from 2010 to *** this period,17.84%of prefecture-level cities had no SCCL,and the average CCI for all prefecture-level citi

关键词： Croplands Slope spectrum Slope-climbing Three-dimensional perspective Multi-scale China

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Two-channel, dual-beam-mode, wavelength-tunable femtosecond optical parametric oscillator

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Advanced Photonics 2020年第4期2卷 24-28页

作者： jintao fan Jun Zhao Liping Shi Na Xiao Minglie Hu Tianjin University College of Precision Instrument and Optoelectronics EngineeringUltrafast Laser LaboratoryTianjinChina Leibniz Universität Hannover Institut für QuantenoptikHannoverGermany Cluster of Excellence PhoenixD(Photonics Opticsand Engineering-Innovation Across Disciplines)HannoverGermany

Optical vortices,which carry orbital angular momentum,offer special capabilities in a host of applications.A single-laser source with dual-beam-mode output may open up new research fields of nonlinear optics and quantum *** demonstrate a dual-channel scheme to generate femtosecond,dualwavelength,and dual-beam-mode tunable signals in the near infrared wavelength ***-wavelength operation is derived by stimulating two adjacent periods of a periodically poled lithium niobate *** by an Yb-doped fiber laser with a Gaussian(lp?0)beam,two tunable signal emissions with different beam modes are observed *** one of the emissions can be tuned from1520 to 1613 nm with the Gaussian(ls?0)beam,the other is capable of producing a vortex spatial profile with different vortex orders(ls?0 to 2)tunable from 1490 to 1549 *** proposed system provides unprecedented freedom and will be an exciting platform for super-resolution imaging,nonlinear optics,multidimensional quantum entanglement,etc.

关键词： nonlinear optics parametric processes optical parametric oscillators ultrafast nonlinear optics

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Generation of sub-three-cycle pulses at 53 MHz repetition rate via nonlinear compression in optical parametric oscillator

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Chinese Optics Letters 2022年第5期20卷 33-37页

作者： Lixin Yuan Yu Cai Yuxi Chu jintao fan Minglie Hu Ultrafast Laser Laboratory Key Laboratory of Opto-electronic Information Science and Technology of Ministry of EducationSchool of Precision Instruments and Opto-electronics EngineeringTianjin UniversityTianjin 300072China Georgia Tech Shenzhen Institute(GTSI) Tianjin UniversityShenzhen 518067China

We report an experimental generation of few-cycle pulses at 53 MHz repetition rate. Femtosecond pulses with pulse duration of 181 fs are firstly generated from an optical parametric oscillator(OPO). Then, the pulses are compressed to subthree-cycle with a hybrid compressor composed of a commercial single-mode fiber and a pair of prisms, taking advantage of the tunability of the OPO and the numerical simulating of the nonlinear compression system. Our compressed optical pulses possess an ultrabroadband spectrum covering over 470 nm bandwidth(at-10 dB), and the output intensity fluctuation of our system is less than 0.8%. These results show that our system can effectively generate few-cycle pulses at a repetition rate of tens of megahertz with excellent long-term stability, which could benefit future possible applications.

关键词： nonlinear compression few cycle pulse optical parametric oscillator

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Challenges and prospects in research on military epidemiology

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Journal of Medical Colleges of PLA(China) 2010年第3期25卷 129-135页

作者： Huang Wen Ju jintao fan Qunming Xiao Lining Li Zhaoshen Department of Field Internal Medicine Changhai Hospital Second Military Medical University Shanghai 200433 China

Epidemiology studies infectious diseases as primary objects, and has formed a scientific system. With the continuous expansion of the scope in epidemiological studies, the development of research methods and the mutual penetration of related disciplines, epidemiology gradually differentiates into many branches. Military epidemiology is just a branch which serves military health and prevention works with epidemic theory. Its study objects are the officers and soldiers in the armed forces, and its mission is to focus not only on peace time, but also on war time and fighting time to prevent from infectious diseases, or even to smash the enemy＇s biological war, which is basically different from the general epidemiology. In recent years, with the policy of reform and opening up, and owing to the improvement of people＇s living standard, the military has significantly improved its living conditions. Meanwhile, because strategic policy and military training has been updated technical diff^culty and intensity in the army have been increased, and disease spectrum has greatly changed. And especially as the theories and methods of modem epidemiology have been introduced into the army, the military epidemiology has been rapidly developed and improved. In short, the military epidemiology has made great achievements in prevention and treatment of common diseases and frequently occurring diseases, in order to guarantee the military members＇ physical and mental health. In the study we review the challenges and prospects for military epidemiology

关键词： Military epidemiology High-tech weapons Stress

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