检索结果-南通市图书馆

Compact and robust supercontinuum generation and post-compression using multiple thin plates

在线全文

学校读者我要写书评

暂无评论

High Power Laser Science and Engineering 2021年第4期9卷 234-241页

作者： Xinhua Xie Yunpei Deng Steven L.Johnson Swiss FEL Paul Scherrer Institute5232 Villi genSwitzerland institute for Quantum Electronics Physics DepartmentETH ZurichETH Zurich8093 ZurichSwitzerland

We report on compact and robust supercontinuum generation and post-compression using transmission of light through multiple thin solid plates at the Swiss FEL X-ray free-electron laser facility.A single stage consisting of three thin plates followed by a chirped mirror compressor achieves compression of initially 30-fs pulses with 800-nm center wavelength to sub-10-fs *** also demonstrate a two-stage implementation to compress the pulses further to sub-5-fs *** the two-stage setup,the generated supercontinuum includes wavelengths ranging from 500 to 1100 *** multiplate setup is compact,robust,and stable,which makes it ideal for applications at free-electron laser facilities such as pump-probe experiments and laser-arrival timing tools.

关键词： post-compression self-phase modulation supercontinuum generation

Novel Heat Transfer Issues Associated with the Design and Safe Operation of the MEGAPIE Spallation Source Target

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2007年第1期16卷 63-78页

作者： Brian L.Smith Thermal Hydraulics Laboratory Paul Scherrer InstituteSwitzerland

Critical heat transfer problems are discussed in the context of the operation of a spallation source target, which represents a first demonstration of the feasibility of an innovative concept for generating energy using a particle accelerator. Within the framework of the umbrella project MEGAPIE, an R＆D support group was organized to take responsibility for target cooling. This involved the use of advanced numerical methods - Computational Fluid Dynamics （CFD） and Finite Element Method （FEM） - validated against suitable experimental data, and by means of appropriate benchmarking exercises. The design studies using CFD resulted in an optimum flow configuration being defined for the coolant circulation. Flow visualization tests were undertaken using a glass/water test section, with the velocity field mapped using optical and ultrasonic measuring techniques. These were followed by heat transfer tests, using the actual target materials （lead-bismuth-eutectic coolant and steel confinement）. Further CFD/FEM work to analyze operational transients and accident sequences was also carded out, and is described in the paper.

关键词： computational fluid dynamics finite element method liquid-metal coolant spallation source target

利用强场多光子电离技术实现对多原子分子离子振动量子态的光学操控

在线全文

学校读者我要写书评

暂无评论

物理学报 2014年第24期63卷 258-263页

作者：刘玉柱 Gerber Thomas Knopp Gregor 南京信息工程大学物理与光电工程学院南京210044 paul scherrer institute 5232 Villigen Switzerland

利用飞秒光电子影像技术研究了碘甲烷分子在飞秒强激光场作用下的多光子电离动力学,在实验上实现了运用飞秒强场多光子电离技术对多原子分子离子的振动量子态进行光学操控.提高了飞秒激光的强度,从1.6×1013W/cm2提高到2.5×1013W/cm2.... 详细信息

利用飞秒光电子影像技术研究了碘甲烷分子在飞秒强激光场作用下的多光子电离动力学,在实验上实现了运用飞秒强场多光子电离技术对多原子分子离子的振动量子态进行光学操控.提高了飞秒激光的强度,从1.6×1013W/cm2提高到2.5×1013W/cm2.在增大的激光强度范围内,发现了新的能量组分,并对此进行归属.通过采集光电离的光电子影像可以得到强场电离后光电子的动能分布和角度分布两方面的信息,前期的研究主要侧重于讨论光电子动能随光强的变化,重点讨论了光电子角度分布随光强的变化,通过观察光电子角度分布的变化趋势对振动量子态调控机理进一步认识.

关键词：强场电离多光子电离光学操控角分辨

树年轮纤维素稳定同位素比率的生态学意义(英文)

在线全文

学校读者我要写书评

暂无评论

植物生态学报 2002年第3期26卷 381-384页

作者： Lin Guanghui Rolf Siegwolf Biosphere 2 Center of Columbia University 32540 S. Biosphere Road 美国 Laboratory of Atmospheric Chemistry Stable Isotope Research Group/Ecosystem Fluxes Paul Scherrer Institute CH-5232 Villigen-PSI 瑞士

Stable isotope ratios in tree-ring cellulose have bee shown to be reliable recorders of changes in the ambient climate (Leuenberger et al., 1998). thus, isotopic fractionations associated with both physical and biochemical processes during cellulose synthesis in higher plants (Epstein & Krishnaumurthy, 1990; Roden et al., 2000; Saucer et al., 1997a; 1997b; 2000) can be used as archives for past climatic indicators. Superimposed on the climatic inducedisotopic signal are the long-term responses of plant physiological processes to past changes in environmental conditions including CO_2 enrichment.

关键词：树年轮纤维素稳定同位素比率生态学气候变化

Generation of millijoule-level sub-5 fs violet laser pulses

在线全文

学校读者我要写书评

暂无评论

High Power Laser Science and Engineering 2024年第2期12卷 33-40页

作者： Xinhua Xie Yi Hung Yunpei Deng Adrian L.Cavalieri Andrius Baltuška Steven L.Johnson SwissFEL Paul Scherrer InstituteVilligen PSISwitzerland Photonics institute Technische Universität WienViennaAustria institute of Applied Physics University of BernBernSwitzerland institute for Quantum Electronics Physics DepartmentETH ZurichZurichSwitzerland

We demonstrate the generation,spectral broadening and post-compression of second harmonic pulses using a thin beta barium borate(BBO)crystal on a fused-silica substrate as the nonlinear interaction *** combining second harmonic generation in the BBO crystal with self-phase modulation in the fused-silica substrate,we efficiently generate millijoule-level broadband violet pulses from a single optical *** second harmonic spectrum covers a range from long wave ultraviolet(down to 310 nm)to visible(up to 550 nm)with a bandwidth of 65 ***,we compress the second harmonic beam to a duration of 4.8 fs with a pulse energy of 0.64 mJ(5 fs with a pulse energy of 1.05 mJ)using chirped *** all-solid free-space apparatus is compact,robust and pulse energy scalable,making it highly advantageous for generating intense second harmonic pulses from near-infrared femtosecond lasers in the sub-5 fs regime.

关键词： post-compression second harmonic generation self-phase modulation supercontinuum generation

Uncovering the dominant contribution of intermediate volatility compounds in secondary organic aerosol formation from biomass-burning emissions

在线全文

学校读者我要写书评

暂无评论

National Science Review 2024年第3期11卷 150-158页

作者： Kun Li Jun Zhang David M.Bell Tiantian Wang Houssni Lamkaddam Tianqu Cui Lu Qi Mihnea Surdu Dongyu Wang Lin Du Imad El Haddad Jay G.Slowik Andre S.H.Prevot Environment Research institute Shandong University Laboratory of Atmospheric Chemistry Paul Scherrer Institute

Organic vapors from biomass burning are a major source of secondary organic aerosols(SOAs). Previous smog chamber studies found that the SOA contributors in biomass-burning emissions are mainly volatile organic compounds(VOCs). While intermediate volatility organic compounds(IVOCs) are efficient SOA precursors and contribute a considerable fraction of biomass-burning emissions, their contribution to SOA formation has not been directly observed. Here, by deploying a newly-developed oxidation flow reactor to study SOA formation from wood burning, we find that IVOCs can contribute ～70% of the formed SOA, i.e.>2 times more than VOCs. This previously missing SOA fraction is interpreted to be due to the high wall losses of semi-volatile oxidation products of IVOCs in smog chambers. The finding in this study reveals that SOA production from biomass burning is much higher than previously thought, and highlights the urgent need for more research on the IVOCs from biomass burning and potentially other emission sources.

关键词： atmospheric chemistry biomass burning secondary organic aerosol intermediate volatility organic compounds

Heterometallic Ti-Zr oxo nanocluster photoresists for advanced lithography

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Materials 2024年第10期67卷 3132-3141页

作者： Yang Qiao Guangyue Shi Ou Zhang You Li Michaela Vockenhuber Yasin Ekinci Feng Luo Lei Zhang School of Materials Science and Engineering Nankai UniversityTianjin 300350China institute of Modern Optics College of Electronic Information and Optical EngineeringNankai UniversityTianjin 300350China paul scherrer institute Laboratory for Micro and NanotechnologyVilligen CH-5232Switzerland

Extreme ultraviolet lithography(EUVL)and electron beam lithography(EBL)are considered to be crucial lithography techniques utilized in the fabrication of nanoscale semiconductor ***,the industry currently faces a scarcity of EUV photoresists that meet the increasingly challenging standards in terms of resolution,sensitivity and *** oxo nanoclusters have garnered significant interest in the field of EUV photoresist due to their relatively stronger absorption cross-section for extreme ultraviolet light and lower *** this study,we utilize a heterometallic nanocluster strategy by a combination of titanium and zirconium metals to investigate their solubility,assess the suitability of various developers,and evaluate their performance in electron-beam and EUVL,as well as study their etch resistance for pattern *** demonstrate that R-4 is able to get a critical dimension(CD)of 25 nm at low doses under EBL,as well as 50 nm resolution at EUVL with a remarkable sensitivity of 19.7 mJ cm−*** study offers an efficient heterometallic method for optimizing the lithographic performance of metal oxo nanocluster photoresists,which can benefit the development of commercially viable next-generation EUV photoresists.

关键词： heterometallic nanocluster photoresists electron beam lithography extreme ultraviolet lithography

开裂混凝土中水分侵入过程的可视化追踪及其特征分析

在线全文

学校读者我要写书评

暂无评论

硅酸盐学报 2010年第4期38卷 659-665页

作者：张鹏赵铁军 WITTMANN F H LEHMANN E 金祖权 VONTOBEL P 青岛理工大学土木工程学院 Aedificat institute Freiburg D-79100 FreiburgGermany Department of Spallation Neutron Source Paul Scherrer InstituteCH-5232Villigen PSISwitzerland

采用热中子辐射成像技术,对开裂混凝土中的水分侵入过程进行了试验研究与特征分析。结果表明:中子成像能够突破混凝土材料的非透明性局限,实现对开裂混凝土中水分侵入过程的可视化追踪和水分空间分布的定量计算;水分在开裂混凝土中不仅... 详细信息

采用热中子辐射成像技术,对开裂混凝土中的水分侵入过程进行了试验研究与特征分析。结果表明:中子成像能够突破混凝土材料的非透明性局限,实现对开裂混凝土中水分侵入过程的可视化追踪和水分空间分布的定量计算;水分在开裂混凝土中不仅由与水初始接触面沿垂直方向推进,而且还沿裂缝两侧向其水平方向,以及钢筋与水泥基体界面外围方向同时入侵;裂缝区和钢筋与水泥基体界面区成为水分持续侵入的二次水源;水分侵入初期约2h内,根据试验中裂缝宽度为0.35mm试件的中子图像估算的水分侵入量与称量法测得的水分侵入量基本一致。

关键词：混凝土裂缝水分侵入中子成像可视化

800MeV强流螺旋分离扇回旋加速器理论等时场的建立

在线全文

学校读者我要写书评

暂无评论

800MeV强流螺旋分离扇回旋加速器理论等时场的建立