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High performance computation on beam dynamics problems in high intensity compact cyclotrons

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Science China(Physics,Mechanics & Astronomy) 2011年第S2期54卷 249-254页

作者： ADELMANN andreas Paul Scherrer Institut Villigen CH-5234 Switzerland

This paper presents the research progress in the beam dynamics problems for future high intensity compact cyclotrons by utilizing the state-of-the-art high performance computation technology. A "Start-to-Stop" model, which includes both the interaction of the internal particles of a single bunch and the mutual interaction of neighboring multiple bunches in the radial direction, is established for compact cyclotrons with multi-turn extraction. This model is then implemented in OPAL-CYCL, which is a 3D object-oriented parallel code for large scale particle simulations in cyclotrons. In addition, to meet the running requirement of parallel computation, we have constructed a small scale HPC cluster system and tested its performance. Finally, the high intensity beam dynamics problems in the 100 MeV compact cyclotron, which is being constructed at CIAE, are studied using this code and some conclusions are drawn.

关键词： compact cyclotron space charge effects parallel computation beam dynamics cluster system

The fate of the herbicide propanil in plants of the littoral zone of the Three Gorges Reservoir(TGR),China

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Journal of Environmental Sciences 2016年第10期28卷 24-33页

作者： Zhongli Chen andreas Schaffer Institute for Environmental Research(Biology V) RWTH Aachen UniversityAachen 52074Germany. Nanjing University School of the Environment Nanjing 210023China Chongqing University College of Resource and Eavironmental ScienceChongqing 400030China

The anti-seasonal hydrology with 30 m water fluctuations in the Three Gorges Reservoir(TGR)of China attracts growing environmental and ecological *** investigated the biotransformation of the herbicide propanil in plants dominating in the littoral zone of the TGR by applying the 14C-ring-labeled herbicide into non-aseptic hydroponic plant systems(Cynodon dactylon,Nelumbo nucifera and Bidens pilosa),aseptic plants(Lemna minor and Lemna gibba)and cell suspension cultures(*** and ***).(1)Propanil absorbed in plants of the hydroponic systems was(12.46±1.63)%of applied radioactivity(AR)(***),(52.36±6.38)%(***)and(76.55±6.07)%(***),*** 14C-residues in the plant extractable fractions and the corresponding media were confirmed by radio-Thin Layer Chromatography(TLC),radio-High Performance Liquid Chromatography(HPLC)and Gas Chromatography-Electron Ionization Mass Spectrometry(GC-EIMS)as propanil,3,4-dichloroaniline(DCA)and N-(3,4-dichlorophenyl)-β-D-glucopyranosylamine(Glu-DCA).(2)About 8%of AR was taken up by both aseptic plants,from which 7.0%of AR was extracted and identified also as propanfl,DCA and Glu-DCA.(3)Concerning cell suspension cultures,(39.22±9.39)%of AR was absorbed by *** after 72 hr,whereas the accumulated 14C-propanil by *** cell suspension culture amounted to(65.04±1.72)%after 7 *** identified compounds in cell cultures are consistent with those in the tested *** of the pesticide residues in the intact plants were un-extractable,which are recognized as the end of the detoxificafion *** therefore consider these plants as suitable for the phytoremediation of the herbicide propanil in the TGR region.

关键词： Three Gorges Reservoir(TGR) Propanil Plant degradation Non-extractable residues(NER)

REGENERATION FACTOR 1, a peptide boost for wound healing and plant biotechnology

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Molecular Plant 2024年第9期17卷 1333-1334页

作者： andreas Schaller University of Hohenheim Department of Plant Physiology and Biochemistry70593 StuttgartGermany

Plants respond to wounding such as caused by insect herbivores by activating their defenses and thus increasing their resistance against attacking pests and opportunistic pathogens(Howe and Schaller,2008).The phenomenon was first described more than 50 years ago by Green and Ryan,who reported that wounding triggers tomato and potato plants to produce proteinase inhibitors that inhibit digestive proteases in the gut of leaf-eating insects to starve them of nutrients(Green and Ryan,1972).They also observed that the accumulation of proteinase inhibitors is not restricted to wounded leaves but occurs throughout the aerial parts of the *** search for a chemical signal that is released locally in response to wounding and that mediates systemic activation of defense gene expression led to the identification of systemin,the first ever peptide with hormonelike activity in plants(Pearce et al.,1991).These seminal findings sparked much research into systemic defense responses and peptide signaling in general,and we know now that systemin is one of many phytocytokines that regulate a multitude of immune responses in plants(Schilmiller and Howe,2005;Gust et al.,2017).

关键词： wound activation defense

Snapshot imaging of ultrashort electron bunches

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Light(Science & Applications) 2024年第7期13卷 1226-1228页

作者： andreas Döpp Ludwig-Maximilian-Universität München Am Coulombwall 185748GarchingGermany Max Planck Institut für Quantenoptik Hans-Kopfermann-Strasse 1Garching85748Germany

New measurements combine spatial and temporal information from optical transition radiation to estimate the three-dimensional structure of electron bunches from a laser wakefield accelerator.

关键词： ultrashort Snapshot electron

Characteristics of elution profile in radial chromatography under linear conditions

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Science China Chemistry 2005年第4期48卷 352-360页

作者： andreas Seidel-Morgenstern Max-Planck-Institut für Dynamik Komplexer Technischer Systeme 39106MagdeburgGermany

Based on the mass balance equations of solute transfer in the radial chroma-tographic column,the theoretical expression to describe the column efficiency and shape of elu-tion profile is obtained under linear isotherm ***,the tendency for the variation of column efficiency and symmetry of peak profile is systematically *** results showed that in radial chromatography the relationship between the column efficiency and volumetric flow rate is similar with that relationship in axial chromatography;relatively high column efficiency still can be obtained under high flow rate in radial *** the increase of retention factor of solutes and injection time,the column efficiency decreases *** effect of column diameter and column length on the column efficiency interfere with each *** is more advantageous to increase the column efficiency by applying columns with larger column diameter and shorter column *** to the discussion of the effect of diffusion on the column efficiency,radial chromatography is proved to be suitable for the separation of samples with relatively high diffusion coefficient,which predicts its obvious advantage in the preparative separation of samples such as proteins and DNA.

关键词： radial chromatography, column efficiency, elution profile, symmetry.

Multi-segment linear gradient optimization strategy based on resolution map in HPLC

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Science China Chemistry 2006年第4期49卷 315-325页

作者： andreas Seidel-Morgenstern Max-Planck-Institut fr Dynamik Komplexer Technischer Systeme Magdeburg 39106 Germany

Based on the mechanism of chromatographic retention (the relationship between the retention of solute and the mobile phase conditions) and method of resolution map, several methods of optimizing multi-segment linear gradient elution conditions were proposed according to the different separation requirements of various samples. These methods were verified using literature data. Moreover, the advantages and disadvantages of these methods were compared. It was proved that the third method is a fast optimization method which is capable of separating all the components with relatively high resolution.

关键词： optimization, multi-segment, linear gradient, resolution map, liquid chromatography.

Micro-annulus generation under downhole conditions: Insights from three-dimensional staged finite element analysis of cement hardening and wellbore operations

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Journal of Rock Mechanics and Geotechnical Engineering 2020年第6期12卷 1185-1200页

作者： Weicheng Zhang andreas Eckert Department of Geosciences and Geological and Petroleum Engineering Missouri University of Science and TechnologyRollaMOUSA

A micro-annulus(MA)is defined as a high permeability zone or gap initiating/occurring at the casingcement and cement-formation interfaces during the wellbore life *** MA can significantly compromise wellbore integrity by establishing enhanced fluid flow *** study uses a staged finite element approach to simulate wellbore integrity during various loading steps of wellbore operations under downhole *** emphasis is placed on the processes of cement poro-elastic property evolution,volume variation,and pore pressure variation as part of the cement hardening *** resulting state of stress during the life cycle of a typical injection well(***,completion,and injection)is analyzed to assess the onset and evolution of micro-annuli at various interfaces of the composite wellbore system under downhole *** results show that cement shear failure is observed at the casing-cement interface during pressure testing(excessive wellbore pressure);and tensile debonding failure initiates at the cement-formation interface due to cement shrinkage during hardening and injection-related cooling(thermal cycling).Sensitivity analyses considering several parameters show that:(1)the degree of poro-elastic bulk shrinkage has significant implications for both shear and tensile failure initiation e the less the cement shrinks,the less likely the failure initiation is;(2)cement integrity increases with increasing depth;(3)cement pore pressure evolution has significant implications for tensile failure e if cement pore pressure decreases more,higher temperature differences can be sustained before an MA occurs;and(4)cement temperature fluctuations during hardening promote initiation of debonding *** summary,the results presented indicate that establishing downhole conditions to quantitatively analyze MA generation is *** results are different compared to laboratory studies without considering/simulating downhole *** kno

关键词： Micro-annulus Debonding Staged finite element analysis Cement hardening Poro-elastic bulk shrinkage Pore pressure Temperature fluctuation

Is hepatitis B-virucidal validation of biocides possible with the use of surrogates?

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World Journal of Gastroenterology 2014年第2期20卷 436-444页

作者： andreas Sauerbrei Institute of Virology and Antiviral Chemotherapy Jena University ClinicFriedrich Schiller University of JenaD-07745 JenaGermany

The hepatitis B virus(HBV)is considered to be a major public health problem worldwide,and a significant number of reports on nosocomial outbreaks of HBV infections have been *** of indirect HBV transmission by contaminated objects is only possible through the use of infection-control principles,including the use of chemical biocides,which are proven to render the virus *** virucidal activity of biocides against HBV cannot be predicted;therefore,validation of the virucidal action of disinfectants against HBV is ***,feasible HBV infectivity assays have not yet been ***,surrogate models have been proposed for testing the efficacy of biocides against *** of these assays do not correlate with HBV ***,the most promising and feasible assay is the use of the taxonomically related duck hepatitis B virus(DHBV),which belongs to the same Hepadnaviridae virus *** paper reviews the application of DHBV,which can be propagated in vitro in primary duck embryonic hepatocytes,for the testing of biocides and describes why this model can be used as reliable method to evaluate disinfectants for efficacy against *** susceptibility levels of important biocides,which are often used as ingredients for commercially available disinfectants,are also described.

关键词： Hepatitis B virus Surrogate model Duck hepatitis B virus Disinfectants Testing virucidal efficacy

High Responsivity and Ultra-Low Detection Limits in Nonlinear a-Si:H p-i-n Photodiodes Enabled by Photogating

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Photonic Sensors 2023年第4期13卷 27-38页

作者： andreas BABLICH Maurice MÜLLER Rainer BORNEMANN andreas NACHTIGAL Peter HARING BOLÍVAR Institute of Graphene-Based Nanotechnology University of SiegenHölderlinstr.357076 SiegenGermany Institute of High Frequency and Quantum Electronics University of SiegenHölderlinstr.357076 SiegenGermany

Photodetectors operating at the wavelength in the visible spectrum are key components in high-performance optoelectronic *** this work,massive nonlinearities in amorphous silicon p-i-n photodiodes enabled by the photogating are presented,resulting in responsivities up to 744 mA/W at blue *** detectors exhibit significant responsivity gains at optical modulation frequencies exceeding MHz and a more than 60-fold enhanced spectral response compared to the non-gated *** detection limits down to 10.4 nW/mm^(2) and mean signal-to-noise ratio enhancements of 8.5dB are demonstrated by illuminating the sensor with an additional 6.6μW/mm^(2) red ***-optical simulations verify photocarrier modulation due to defect-induced field screening to be the origin of such high responsivity *** experimental results validate the theory and enable the development of commercially viable and complementary metal oxide semiconductor(CMOS)compatible high responsivity photodetectors operating in the visible range for low-light level imaging and detection.

关键词： Photogating amorphous silicon a-Si:H nonlinearity photodetector responsivity gain