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Sub-50 fs pulses at 2050 nm from a picosecond Ho:YLF laser using a two-stage Kagome-fiber-based compressor

Photonics Research 2022年第3期10卷 637-645页

作者： Krishna Murari Giovanni Cirmi Hüseyin Cankaya Gregory J.Stein Benoit Debord Frederic Gerome Felix Ritzkosky Fetah Benabid Oliver Muecke franz X.Kärtner Center for Free Electron Laser Science CFEL Deutsches Elektronen-Synchrotron DESY22607 HamburgGermany Max-Planck Institute for Structure and Dynamics of Matter(MPSD) 22761 HamburgGermany ELI-ALPS ELI-HU Non-Profit Ltd.Szeged H-6728Hungary The Hamburg Center for Ultrafast Imaging&Department of Physics University of Hamburg22761 HamburgGermany GPPMM Group XLIM Research InstituteUMR 7252 CNRSUniversity of LimogesLimogesFrance show less

The high-energy few-cycle mid-infrared laser pulse beyond 2μm is of immense importance for attosecond science and strong-field ***,the limited gain bandwidth of laser crystals such as Ho:YLF and Ho:YAG allows the generation of picosecond(ps)long pulses and,hence,makes it challenging to generate few-cycle pulse at 2μm without utilizing an optical parametric chirped-pulse amplifier(OPCPA).Moreover,the exclusive use of the near-infrared wavelength has limited the generation of wavelengths beyond 4μm(OPCPA).Furthermore,high harmonic generation(HHG)conversion efficiency reduces dramatically when driven by a long-wavelength *** schemes such as multi-color HHG have been proposed to enhance the harmonic ***,it is highly desirable to generate few-cycle to femtosecond pulses from a 2μm laser for driving these ***,we utilize two-stage nonlinear spectral broadening and pulse compression based on the Kagome-type hollow-core photonic crystal fiber(HC-PCF)to compress few-ps pulses to sub-50 fs from a Ho:YLF amplifier at 2μm at 1 kHz repetition *** demonstrate both experimentally and numerically the compression of 3.3 ps at 140μJ pulses to 48 fs at 11μJ with focal intensity reaching 10^(13)W/cm^(***,this system can be used for driving HHG in solids at 2μ*** the first stage,the pulses are spectrally broadened in Kagome fiber and compressed in a silicon-based prism compressor to 285 fs at a pulse energy of 90μ*** the second stage,the 285 fs pulse is self-compressed in air-filled *** fine-tuning of the group delay dispersion(GDD)externally in a 3 mm window,a compressed pulse of 48 fs is *** leads to a 70-fold compression of the ps pulses at 2050 *** further used the sub-50 fs laser pulses to generate white light by focusing the pulse into a thin medium of YAG.

关键词： fiber amplifier compressor

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Modeling and simulation of microstructure in metallic systems based on multi-physics approaches

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npj Computational Materials 2022年第1期8卷 867-881页

作者： Jaber Rezaei Mianroodi Pratheek Shanthraj Chuanlai Liu Samad Vakili Sharan Roongta Nima Hamidi Siboni Nathan Perchikov Yang Bai Bob Svendsen franz Roters Dierk Raabe Martin Diehl Microstructure Physics and Alloy Design Max-Planck-Institut für Eisenforschung40237DüsseldorfGermany Ergodic Labs Lohmühlenstraße12435BerlinGermany The Department of Materials The University of ManchesterManchesterM139PLUK Material Mechanics RWTH Aachen University52062AachenGermany Department of Computer Science KU LeuvenCelestijnenlaan 200A3001LeuvenBelgium Department of Materials Engineering KU LeuvenKasteelpark Arenberg 443001LeuvenBelgium

The complex interplay between chemistry,microstructure,and behavior of many engineering materials has been investigated predominantly by experimental *** to the increase in computer power,advances in computational modeling methods have resulted in a level of sophistication which is comparable to that of *** the continuum level,one class of such models is based on continuum thermodynamics,phase-field methods,and crystal plasticity,facilitating the account of multiple physical mechanisms (multi-physics) and their interaction during microstructure *** paper reviews the status of simulation approaches and software packages in this field and gives an outlook towards promising research directions.

关键词： computer microstructure metallic

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Recording Spatially Resolved Plasma Parameters in Microwave-Driven Plasmas

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Plasma Science and Technology 2013年第1期15卷 43-51页

作者： Gerhard franz Florian SCHAMBErgER Igor KRSTEV Stefan UMRATH Munich University of Applied Sciences Munich D-80335

In an almost cubical reactor 90 1 in volume which is intended to deposit organic polymers by plasma-enhanced chemical vapor deposition （PECVD）, microwave power is coupled into the volume via a quartz window which extends to approximately 1/10 of the sidewall area. Since the plasma is excited locally, plasma parameters like electron temperature and plasma density are expected to exhibit a spatial variation. The compilation of these plasma quantities has been accomplished with a bendable single Langmuir probe. To isolate the tungsten wire against its grounded housing tube, it was coated with polyparylene. After having compared this construction with our Langmuir probe, which has been now in use for more than a decade, we have taken data of more than half the volume of the reactor with argon and have found a definitive radial inhomogenity for all plasma parameters. To investigate whether this conduct can be determined applying optical emission spectroscopy, we improved our spectrometer which had been used for endpoint detection purposes and plasma diagnostics in chlorine-containing ambients where we could detect also a spatial dependence. This behavior is discussed in terms of Lieberman＇s global model.

关键词： high frequency and RF discharges optical measurements electric and mag-netic measurements

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黄素体系电子转移过程光谱研究

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光谱学与光谱分析 2022年第2期42卷 368-375页

作者：万浩宇周子雄吴俊彪 J rg Matysik 王孝杰国防科技大学文理学院生物与化学系湖南长沙410073 Institut für Analytische Chemie Universit t Leipzig04103 LeipzigGermany

黄素类物质在生物体内广泛存在,是许多电子转移反应的活性中心,也是电子传递链的重要组成部分。其受到光照激发后引起的电子转移,是许多生命过程的基础与起始步骤。特别地,一种名为隐花色素的黄素蛋白在光激发后经一系列电子转移形成自... 详细信息

黄素类物质在生物体内广泛存在,是许多电子转移反应的活性中心,也是电子传递链的重要组成部分。其受到光照激发后引起的电子转移,是许多生命过程的基础与起始步骤。特别地,一种名为隐花色素的黄素蛋白在光激发后经一系列电子转移形成自旋相关自由基对,被认为是最有可能的生物磁敏物质,更使黄素体系电子转移过程的动力学,特别是自旋动力学过程倍受关注。对黄素电子转移过程及相关机理进行研究,有助于厘清多种生命过程的化学机理与影响因素。为此,科学界综合运用了多种仪器与测试手段,其中主要包括紫外-可见光谱,荧光光谱,瞬态吸收光谱,光化学诱导动态核极化(Photo-CIDNP)技术等。通过多年的研究,对黄素在生物体内的作用机理与电子转移过程的认识经历了由浅入深,不断深入的过程。紫外-可见光谱(UV-Vis)主要用于研究黄素系统中的电子激发,自旋动力学和电子转移。结合理论计算,UV-Vis还可以识别电子转移中涉及的基团并进行定量分析。荧光光谱可以识别电子受激发的物质,在反应过程中观察黄素和半醌中间体的产生和消耗,并确定其氧化还原和质子化状态。瞬态吸收光谱适于观测反应过程中出现的短寿命物种,其中飞秒泵浦探测技术的引入大大提高了观测的时间分辨率,并且可以通过光谱特征区分单重态和三重态的自由基对。光化学诱导动态核极化核磁共振(NMR)可以直接观察电子-核自旋动力学过程。磁场依赖性photo-CIDNP NMR揭示了控制单重态与三重态互变的因素,并提出了生物地磁导航可能依赖的化学机制。腔吸收与单分子光谱的运用,从技术上提高了实验装置的灵敏度并降低检测限。主要介绍黄素体系电子转移过程研究所运用的各种光谱手段与取得的成果,并展望其未来。

关键词：黄素电子转移光谱自旋动力学磁感应

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Effect of Sacrificial Anode Protection for Steel Pipe Piles at Dandong Port

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China Ocean Engineering 1998年第1期13卷 113-120页

作者： Zhu, XC Ge, Y Ge, rg Nanjing Hydraul Res Inst Dept Mat & Struct Nanjing 210024 Peoples R China

The sacrificial anode protection system for the steel pipe piles of the 3rd berth of Dandong; wharf at Dandong port has operated for eight years. In this paper, the program design and the protection effect of the sacrificial anode protection system are presented. The results of various inspections show that the piles are protected very satisfactorily.

关键词： steel pipe pile corrosion sacrificial anode cathodic protection protection potential protection percentage

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Endoscopic resection techniques for colorectal neoplasia:Current developments

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World Journal of Gastroenterology 2019年第3期25卷 300-307页

作者： franz Ludwig Dumoulin Ralf Hildenbrand Department of Medicine and Gastroenterology Gemeinschaftskrankenhaus Bonn Institute for Pathology Bonn Duisdorf

Endoscopic polypectomy and endoscopic mucosal resection(EMR) are the established treatment standards for colorectal polyps. Current research aims at the reduction of both complication and recurrence rates as well as on shortening procedure times. Cold snare resection is the emerging standard for the treatment of smaller(rger flat or sessile lesions. The technique has obvious advantages in the treatment of high-grade dysplasia and early cancer. Due to its minimal recurrence rate, it may also be an alternative to fractionated EMR of larger flat or sessile lesions. However, ESD is technically demanding and burdened by longer procedure times and higher costs. It should therefore be restricted to lesions suspicious for high-grade dysplasia or early invasive *** latest addition to endoscopic resection techniques is endoscopic fullthickness resection with specifically developed devices for flexible *** method is very useful for the treatment of smaller difficult-to-resect lesions,e.g., recurrence with scar formation after previous endoscopic resections.

关键词： Colorectal neoplasia Colorectal cancer screening Cold snare resection Endoscopic polypectomy Endoscopic mucosal resection Endoscopic submucosal dissection Endoscopic full-thickness resection Adenoma recurrence rate

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Ca^(2+)-dependent successive phosphorylation of vacuolar transporter MTP8 by CBL2/3-CIPK3/9/26 and CPK5 is critical for manganese homeostasis in Arabidopsis

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Molecular Plant 2022年第3期15卷 419-437页

作者： Chuanfeng Ju Zhenqian Zhang Jinping Deng Cuicui Miao Zhangqing Wang Lukas Wallrad Laiba Javed Dali Fu Ting Zhang Jörg Kudla Zhizhong Gong Cun Wang State Key Laboratory of Crop Stress Biology for Arid Areas College of Life Sciencesand Institute of Future AgricultureNorthwest Agriculture&Forestry UniversityYanglingShaanxi 712100China State Key Laboratory of Plant Physiology and Biochemistry College of Biological SciencesChina Agricultural UniversityBeijing 100193China Institut fur Biologie und Biotechnologie der Pflanzen Westfälische Wilhelms-Universität48149 MünsterGermany College of Life Sciences Hebei UniversityBaodingChina

Manganese(Mn)is an essential micronutrient for all living ***,excess Mn supply that can occur in acid or waterlogged soils has toxic effects on plant physiology and *** a variety of Mn transporter families have been characterized,we have only a rudimentary understanding of how these transporters are regulated to uphold and adjust Mn homeostasis in ***,we demonstrate that two calcineurin-B-like proteins,CBL2/3,and their interacting kinases,CIPK3/9/26,are key regulators of plant Mn *** mutants lacking CBL2 and 3 or their interacting protein kinases CIPK3/9/26 exhibit remarkably high Mn ***,CIPK3/9/26 interact with and phosphorylate the tonoplast-localized Mn and iron(Fe)transporter MTP8 primarily at Ser35,which is conserved among MTP8 proteins from various *** transport complementation assays in yeast combined with multiple physiological assays indicate that CBL-CIPK-mediated phosphorylation of MTP8 negatively regulates its transport activity from the cytoplasm to the ***,we show that sequential phosphorylation of MTP8,initially at Ser31/32 by the calcium-dependent protein kinase CPK5 and subsequently at Ser35 by CIPK26,provides an activation/deactivation fine-tuning mechanism for differential regulation of Mn ***,our findings define a two-tiered calcium-controlled mechanism for dynamic regulation of Mn homeostasis under conditions of fluctuating Mn supply.

关键词： manganese Ca^(2+) calcineurin B-like proteins(CBLs) CBL-interacting protein kinases(CIPKs) Mn transporter MTP8 calcium-dependent protein kinases(CPKs)

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Wetting and its influence on the filtration ability of ceramic foam filters

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Particuology 2015年第1期13卷 50-57页

作者： Fabian Heuzeroth J?rg Fritzsche Urs A.Peuker Institute of Mechanical Process Engineering and Mineral Processing

Deep bed filtration in aqueous media is a well-known process for solid-liquid separation. However, the use of deep bed filtration for the purification of metal melts is a relatively new field of application, In particular, the separation mechanism of metal melts filtration is a new area for investigation. The current paper aims at examining the influence of wetting on the filtration efficiency of ceramic foam filters that is an important feature of the metal melts filtration process. A model system was designed using water and alumina particles （〈200μm）. The particles and filter medium were coated to model poor wetting. Thus, examination of the influence of wetting on the adhesion energy and filtration performance was possible. Furthermore, the effect of fluid velocity was studied. To this end, the experiments were carried out under atmospheric conditions and at 20℃. The findings showed that poor wetting between the fluid and solid phase significantly increased the filtration efficiency.

关键词： Deep bed filtration Adhesion energy Atomic force microscopy Wetting

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From Single Droplet to Column Design

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Tsinghua Science and Technology 2006年第2期11卷 212-216页

作者： Hans-Jrg Bart Institute of Thermal Process Engineering TU Kaiserslautern D-67653 Kaiserslautern Germany

The technique state to design counter-current extraction columns is based on the performance of pilot plant experiments. The modelling is then either with the equilibrium or dispersion model, whereas in the latter the dispersion coefficient accounts for all hydrodynamic non-idealities. A new approach uses single droplet experiments to obtain the basic laws and functions governing droplet breakage, coalescence, relative velocity, and axial dispersion when using droplet populance balance models （DPBM）. The hydrodynamics simulation results show that the mean Sauter diameter, hold-up, and concentration profiles could be well predicted, which promotes the use of DPBM models for further applications in industrial scale.

关键词： single droplet column design countercurrent extraction droplet populance balance model

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Sequence architecture of a Jurassic ramp succession from Gebel Maghara(North Sinai,Egypt):Implications for eustasy

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Journal of Palaeogeography 2015年第3期4卷 305-330页

作者： Ahmed Awad Abdelhady franz Theodor Fürsich Geology Department Faculty of ScienceMinia University FG Pal?oumwelt Geozentrum Nordbayern der Universit?t Erlangen

The Jurassic succession at Gebet Maghara, North Sinai, Egypt, represents a mixed carbonate-siticictastic sequence. Combining information from both fossits and rocks attowed a ptausibte reconstruction of the depositionat environments and of the basin evotution. The Ju- rassic succession of Gebel Maghara was deposited on a ramp, and the architecture of the ramp facies was strongty controtted not onty by sea-revel changes but atso by extensionat tectonics in connection with rifting of the Tethys, North Gondwana. Seven tectonicalty modified thirdorder sequences （DS 1-DS 7） have been recognized. The first three sequences （DS 1-DS 3）, ranging from the Toarcian to the Bajocian, record sea invasion （intertidat to shattow subtida[lconditions） across an intracratonic area as a resutt of eustatic sea-fever changes during a quiescent rift stage. The remaining sequences （DS 4-DS 7） reflect open marine mid to outer ramp settings. Non-marine conditions around the Bajocian-Bathonian boundary, documented by catiche, represent the maximum regression of the sea. During an active extensionat stage, horsts, which formerty acted as barriers separating the Maghara sub-basin from the main ocean, subsided. Subsequent rejuvenation and reactivation of fautts shifted the homoctinat physiography of the ramp to a distatty steepened ramp during the earty Bathonian, creating a 200-m-thick dettaic wedge. SimiLar processes during the earty Kimmeridgian created a catcirudite-catcarenite succession of stope origin. The diversity and the epifaunat/infaunat percentage of the macrofauna disptay a cyctic pattern which coincides more or tess with the sequence stratigraphic architecture.

关键词： facies sequence stratigraphy ramp extensional basin Jurassic Gebel Maghara Egypt

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