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A new computational approach for modeling diffusion tractography in the brain

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Neural Regeneration Research 2017年第1期12卷 23-26页

作者： harsha T.Garimella Reuben h.kraft Department of Mechanical and Nuclear Engineering Department of Biomedical EngineeringThe Pennsylvania State UniversityUniversity ParkPAUSA

Computational models provide additional tools for studying the brain,however,many techniques are currently disconnected from each *** is a need for new computational approaches that span the range of physics operating in the *** this review paper,we offer some new perspectives on how the embedded element method can fill this gap and has the potential to connect a myriad of modeling *** embedded element method is a mesh superposition technique used within finite element *** method allows for the incorporation of axonal fiber tracts to be explicitly ***,we explore the use of the approach beyond its original goal of predicting axonal strain in brain *** explore the potential application of the embedded element method in areas of electrophysiology,neurodegeneration,neuropharmacology and *** conclude that this method has the potential to provide us with an integrated computational framework that can assist in developing improved diagnostic tools and regeneration technologies.

关键词： embedded elements finite element analysis computational biomechanics explicit axonal fiber tracts neural regeneration diffusion tractography

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Particle-size-dependent upconversion luminescence of NaYF4:Yb,Er nanoparticles in organic solvents and water at different excitation power densities

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Nano Research 2018年第12期11卷 6360-6374页

作者： Marco kraft Christian Würth Verena Muhr Thomas hirsch Ute Resch-Genger Federal Institute for Matefiab Research and Testing (BAM) Division1.2BiophotonicsRichard-Willstaetter-Str.1112489BerlinGermany Institute of Analytical Chemistry Chemo-and BiosensorsUniversity of Regensburg93040RegensburgGermany

A systematic study of the luminescence properties of monodisperse β-NaYF4: 20% Yb3+, 2% Er3+ upconversion nanoparticles (UCNPs) with sizes ranging from 12–43 nm is presented utilizing steady-state and time-resolved fluorometry. Special emphasis was dedicated to the absolute quantification of size- and environment-induced quenching of upconversion luminescence (UCL) by high-energy O–h and C–h vibrations from solvent and ligand molecules at different excitation power densities (P). In this context, the still-debated population pathways of the 4F9/2 energy level of Er3+ were examined. Our results highlight the potential of particle size and P value for color tuning based on the pronounced near-infrared emission of 12 nm UCNPs, which outweighs the red Er3+ emission under “strongly quenched” conditions and accounts for over 50% of total UCL in water. Because current rate equation models do not include such emissions, the suitability of these models for accurately simulating all (de)population pathways of small UCNPs must be critically assessed. Furthermore, we postulate population pathways for the 4F9/2 energy level of Er3+, which correlate with the size-, environment-, and P-dependent quenching states of the higher Er3+ energy levels.

关键词： upconversion nanoparticle quenching diameter water cyclohexane

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基于“双毯法”的植物叶态萎蔫辨识研究

农业机械学报 2016年第11期47卷 322-328页

作者：张新高超 Martin kraft 赵燕东北京林业大学工学院北京100083 德国联邦农业林业和渔业研究所农业技术分所布伦瑞克38116

为实现植物生命需水状况的无损检测,通过定量辨识植物叶态萎蔫特征反映植物亏水胁迫状况,基于分形理论"双毯法"定义了萎蔫指数LDBM,利用基于激光三角原理的三维激光扫描仪获取植物叶片表型点云数据,以西葫芦、秋葵、葫芦、南瓜4种植物... 详细信息

为实现植物生命需水状况的无损检测,通过定量辨识植物叶态萎蔫特征反映植物亏水胁迫状况,基于分形理论"双毯法"定义了萎蔫指数LDBM,利用基于激光三角原理的三维激光扫描仪获取植物叶片表型点云数据,以西葫芦、秋葵、葫芦、南瓜4种植物为研究对象,结合饱和水汽压差与光合有效辐射2种微环境参数,进行了植物叶态萎蔫定量辨识研究。试验分析了4种植物萎蔫指数LDBM的日变化曲线,证明LDBM用于表征叶态萎蔫状况是合理和可行的;分析了萎蔫指数LDBM与微环境参数的相关性,4种植物LDBM与饱和水汽压差相关系数均大于0.81,与光合有效辐射相关系数均大于0.71,与2种参数都有很强的正相关性;并且与基于离散时域傅里叶变换定义的萎蔫指数L2DFT进行了对比,LDBM与L2DFT呈负相关性,4种植物的相关系数均大于0.82,表明LDBM能够准确地定量表征叶态萎蔫。

关键词：叶态萎蔫双毯法植物表型三维激光扫描

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Bending reliability of screen-printed vias for a flexible energy module

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npj Flexible Electronics 2020年第1期4卷 210-217页

作者： Manu kujala Terho kololuoma Jari keskinen Donald Lupo Matti Mäntysalo Thomas M.kraft Faculty of Computing and Electrical Engineering Tampere University(formerly Tampere University of Technology)Korkeakoulunkatu 3FI-33720TampereFinland Faculty of Information Technology and Communication Sciences Tampere UniversityKorkeakoulunkatu 3TampereFI-33720Finland Sasken Finland Oy Vissavedentie 1FI-69600KaustinenFinland VTT Technical Research Centre of Finland Ltd. Kaitoväylä1OuluFI-90590Finland

The future of printed electronics involves advancements not only related to full system integration,but also lean process manufacturing.A critical aspect of this progress is developed in this study,which evaluates a highly flexible screen printed through-hole-via using silver microparticle inks,for applications in energy harvesting and storage *** printed vias’fabrication and durability are evaluated by means of a double sided screen-printing method and repetitive(cyclic)bending ***,through 125-µm-thick PET foil,were laser cut(nominally 50,100,150,and 200µm diameters)then filled,and simultaneously connected to adjacent vias by screen *** investigate the use of the printed via in a monolithic energy module,the vias were used for the fabrication of a flexible printed supercapacitor containing aqueous electrolyte and carbon *** results indicate that the lower viscosity silver ink(DuPont 5064h)fills the via less effectively than the higher viscosity ink(Asahi LS411AW),and as the via size increases(≥150µm diameter)via walls are coated rather than ***,the more viscous ink fills the via thoroughly and exhibited a 100%yield(1010 vias;100µm nominal via diameter)with the two-step direct screen-printing *** 10-mm radius bending test showed no signs of via specific breakdown after 30,000 *** results indicate that this via filling process is likely roll-to-roll compatible to enable multi-layered printed electronic devices.

关键词： silver printing nominal

Toward optical coherence tomography on a chip: in vivo three-dimensional human retinal imaging using photonic integrated circuit-based arrayed waveguide gratings

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Light(Science & Applications) 2021年第1期10卷 71-85页

作者： Elisabet A.Rank Ryan Sentosa Danielle J.harper Matthias Salas Anna Gaugutz Dana Seyringer Stefan Nevlacsil Alejandro Maese-Novo Moritz Eggeling Paul Muellner Rainer hainberger Martin Sagmeister Jochen kraft Rainer ALeitgeb Wolfgang Drexler Center for Medical Physics and Biomedical Engineering Medical University of ViennaWaehringer Guertel 18-20/4 L1090 ViennaAustria Research Centre for Microtechnology Vorarlberg University of Applied SciencesHochschulstrasse 16850 DornbirnAustria AIT Austrian Institute of Technology Gmbh Gieffinggasse 41210 ViennaAustria ams AG Tobelbader Strasse 308141 PremstaettenAustria

In this work,we present a significant step toward in vivo ophthalmic optical coherence tomography and angiography on a photonic integrated *** diffraction gratings used in spectral-domain optical coherence tomography can be replaced by photonic integrated circuits comprising an arrayed waveguide *** arrayed waveguide grating designs with 256 channels were tested,which enabled the first chip-based optical coherence tomography and angiography in vivo three-dimensional human retinal *** 1 supports a bandwidth of 22nm,with which a sensitivity of up to 91 dB(830μW) and an axial resolution of 10.7 pm was *** 2 supports a bandwidth of 48 nm,with which a sensitivity of 90 dB(480μW) and an axial resolution of 6.5μm was *** silicon nitride-based integrated optical waveguides were fabricated with a fully CMOS-compatible process,which allows their monolithic co-integration on top of an optoelectronic silicon *** a benchmark for chip-based optical coherence tomography,tomograms generated by a commercially available clinical spectral-domain optical coherence tomography system were compared to those acquired with on-chip *** similarities in the tomograms demonstrate the significant clinical potential for further integration of optical coherence tomography on a chip system.

关键词： waveguide arrayed optical

火星Thaumasia高原上具原始岩浆成分的岩墙:对Tharsis火山作用和水手大峡谷扩张的意义

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火星Thaumasia高原上具原始岩浆成分的岩墙:对Tharsis火山作用和...

Enhanced ion acceleration from transparency-driven foils demonstrated at two ultraintense laser facilities

第十届全国月球科学与比较行星学陨石学与天体化学学术研讨会

作者：黄俊 C.S.Edwards B.h.N.horgan P.R.Christensen M.D.kraft 肖龙赵健楠中国地质大学(武汉)行星科学研究所 Mars Space Flight Facility School of Earth and Space ExplorationArizona State UniversityTempeAZ85287-6305USA

我们利用热发射成像系统(Thermal Emission Imaging System:ThEMIS),结构相机(Context Camera:CTX),高分辨率科学相机(high Resolution Imaging Science Experiment:hiRISE)和火星小型成像光谱仪(Compact ReconnaissanceImaging SpectrometerforMars:CRISM)的数据,在火星Thaumasia高原发现了几个暴露地表的岩墙。这些岩墙绵延数十到上百千米,平均宽度约为50米。这些岩墙呈典型的"雁列式"分布,它们切割了早先的地质单元,包括该地区广泛分布的皱脊。这些岩墙及与之相关的裂隙式喷发形成的岩石,相对于周围物质具有较高的热惯量(高出38%),并且它们具有结实的形貌。这些岩墙含有富镁的橄榄石,一部分还含有高钙辉石,这些矿物指示形成这些岩墙的岩浆的成分较为原始。我们认为这些岩墙为该地区富含橄榄石的玄武岩岩浆的侵位提供了通道,并且这些岩浆可能来源于Tharsis地幔柱。这些观测结果为区域地质应力场对水手大峡谷扩张的促进提供了新的证据。

关键词：岩墙 Thaumasia高原火山作用火星

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Light(Science & Applications) 2023年第4期12卷 593-604页

作者： Nicholas P.Dover Tim Ziegler Stefan Assenbaum Constantin Bernert Stefan Bock Florian-Emanuel Brack Thomas E.Cowan Emma J.Ditter Marco Garten Lennart Gaus Ilja Goethel George S.hicks hiromitsu kiriyama Thomas kluge James k.koga Akira kon kotaro kondo Stephan kraft Florian kroll hazel F.Lowe Josefine Metzkes-Ng Tatsuhiko Miyatake Zulfikar Najmudin Thomas Püschel Martin Rehwald Marvin Reimold hironao Sakaki hans-Peter Schlenvoigt keiichiro Shiokawa Marvin E.P.Umlandt Ulrich Schramm karl Zeil Mamiko Nishiuchi kansai Photon Science Institute National Institutes for Quantum Science and Technology8-1-7 UmemidaiKizugawaKyoto 619-0215Japan The John Adams Institute for Accelerator Science Blackett LaboratoryImperial College LondonLondon SW72AZUnited Kingdom helmholtz-Zentrum Dresden-Rossendorf 01328 DresdenGermany Technische Universitat Dresden 01069 DresdenGermany Interdiscipllinary Graduate School of Engineering Sciences Kyushu University6-1Kasuga-KoenKasugaFukuoka 816-8580Japan

Laser-driven ion sources are a rapidly developing technology producing high energy,high peak current *** suitability for applications,such as compact medical accelerators,motivates development of robust acceleration schemes using widely available repetitive ultraintense femtosecond *** applications not only require high beam energy,but also place demanding requirements on the source stability and *** can be seriously affected by the laser temporal contrast,precluding the replication of ion acceleration performance on independent laser systems with otherwise similar ***,we present the experimental generation of>60 MeV protons and>30 MeV u-1 carbon ions from sub-micrometre thickness Formvar foils irradiated with laser intensities>1021 *** are accelerated by an extreme localised space charge field≥30TVm-1,over a million times higher than used in conventional *** field is formed by a rapid expulsion of electrons from the target bulk due to relativistically induced transparency,in which relativistic corrections to the refractive index enables laser transmission through normally opaque *** replicate the mechanism on two different laser facilities and show that the optimum target thickness decreases with improved laser contrast due to reduced *** demonstration that energetic ions can be accelerated by this mechanism at different contrast levels relaxes laser requirements and indicates interaction parameters for realising application-specific beam delivery.

关键词： acceleration intense transparency

harmonic aspects of wind power integration

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Journal of Modern Power Systems and Clean Energy 2013年第1期1卷 14-21页

作者： Math h.J.BOLLEN kai YANG Electric Power Engineering Lulea University of Technology93187 SkellefteaSweden

This paper discusses a number of ways in which wind power installations can impact the harmonic levels in the power *** turbines are an additional source of harmonic emission,especially when it concerns"non-characteristic harmonics."Parallel resonances can amplify the emission from individual turbines.A mathematical model is developed to quantify this *** resonances can result in high currents,driven by the background voltage distortion in the transmission grid,flowing into thewind *** of the transmission grid will increase lower order harmonics but reduce higher order harmonics.

关键词： Power quality Power system harmonics Wind power

评价双能量CT中高能级单能量重建技术在头颈肿瘤中的应用

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国际医学放射学杂志 2015年第5期 509-510页

作者： M.h.Albrecht J.E.Scholtz J.kraft R.W.Bauer M.kaup P.Dewes 叶露 Department of Diagnostic and Interventional Radiology University Hospital Frankfurt

摘要目的确定双能量CT（DECT）有关头颈部鳞状细胞癌（SCC）病人在高能级单能量（Mono+）中的最佳ke V值。方法对44例[男34例,女10例,平均年龄（55.5±16.0）岁]经组织病理学确诊为头颈部SCC病人的DECT影像进行重建,按照40 ke V、55 ke ... 详细信息

摘要目的确定双能量CT（DECT）有关头颈部鳞状细胞癌（SCC）病人在高能级单能量（Mono+）中的最佳ke V值。方法对44例[男34例,女10例,平均年龄（55.5±16.0）岁]经组织病理学确诊为头颈部SCC病人的DECT影像进行重建,按照40 ke V、55 ke V、70 ke V Mono+和M0.3（30%80 k V）线性混合分组。测量肿瘤、胸锁乳突肌、颈内静脉、下颌下腺和

关键词：头颈肿瘤 CT 病理学确诊颈内静脉下颌下腺噪声比衰减值放射科医师文载 Radiol