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Monte Carlo Simulations of Elastic Scattering with Applications to DC and High Power Pulsed Magnetron Sputtering for Ti3_(S)iC_(2)

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Communications in Computational Physics 2012年第5期11卷 1618-1642页

作者： Jurgen Geiser sven Blankenburg Department of Mathematics Humboldt-Universitat zu BerlinD-10099 BerlinGermany Department of Physics Humboldt-Universitat zu BerlinD-10099 BerlinGermany.

We simulate the particle transport in a thin film deposition process made by PVD(physical vapor deposition)and present several models for projectile and target collisions in order to compute the mean free path and the differential cross section(angular distribution of scattered projectiles)of the scattering process.A detailed description of collision models is of the highest importance in Monte Carlo simulations of high power impulse magnetron sputtering and DC *** derive an equation for the mean free path for arbitrary interactions(cross sections)that includes the relative velocity between the *** apply our results to two major interaction models:hard sphere interaction&screened Coulomb *** types of interaction separate DC sputtering from HIPIMS.

关键词： DC sputtering MAX-phases mean free path particle in cell Monte Carlo collisions Monte Carlo Markov chain

Inducing imperfections in germanium nanowires

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Nano Research 2017年第5期10卷 1510-1523页

作者： Subhajit Biswas sven Barth Justin D. Holmes Materials Chemistry & Analysis Group Department of Chemistry and the Tyndall National lnstitute University College Cork Cork Ireland AMBER@CRANN Trinity College Dublin Dublin 2 Ireland Vienna University of Technology Institute of Materials Chemistry Getreidemarkt 9/BCI02 1060 Vienna Austria

Nanowires with inhomogeneous heterostructures such as polytypes and periodic twin boundaries are interesting due to their potential use as components for optical, electrical, and thermophysical applications. Additionally, the incorporation of metal impurities in semiconductor nanowires could substantially alter their electronic and optical properties. In this highlight article, we review our recent progress and understanding in the deliberate induction of imperfections, in terms of both twin boundaries and additional impurities in germanium nanowires for new/enhanced functionalities. The role of catalysts and catalyst-nanowire interfaces for the growth of engineered nanowires via a three-phase paradigm is explored. Three-phase bottom-up growth is a feasible way to incorporate and engineer imperfections such as crystal defects and impurities in semiconductor nanowires via catalyst and/or interfacial manipulation. ＂Epitaxial defect transfer＂ process and catalyst-nanowire interfacial engineering are employed to induce twin defects parallel and perpendicular to the nanowire growth axis. By inducing and manipulating twin boundaries in the metal catalysts, twin formation and density are controlled in Ge nanowires. The formation of Ge polytypes is also observed in nanowires for the growth of highly dense lateral twin boundaries. Additionally, metal impurity in the form of Sn is injected and engineered via third-party metal catalysts resulting in above-equilibrium incorporation of Sn adatoms in Ge nanowires. Sn impurities are precipitated into Ge bi-layers during Ge nanowire growth, where the impurity Sn atoms become trapped with the deposition of successive layers, thus giving an extraordinary Sn content （〉6 at.%） in Ge nanowires. A larger amount of Sn impingement （〉9 at.%） is further encouraged by utilizing the eutectic solubility of Sn in Ge along with impurity trapping.

关键词： germamum nanowire vapor-liquid-solid (VLS)growth twinning impurity incorporation

Biochemical indicators for neuronal regeneration during intrathecal triamcinolone application in multiple sclerosis

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Neural Regeneration Research 2015年第3期10卷 377-379页

作者： Thomas Müller sven Lütge Department of Neurology St.Joseph Hospital Berlin-Weiβensee

Multiple sclerosis （MS） is a chronic inflammatory disease of the central nervous system （CNS）. Essential charac- teristics are demyelination, inflammation and neurode- generation. This process affects the white and grey matter in the CNS. MS patients experience various progression subtypes in association with the cerebral or spinal, acute inflammatory or glial sclerotic lesions （Mtiller, 2009）. Most patients end up in a progressive, smouldering, chronic inflammatory process （MUller, 2009）. Current predominantly used 1.5 respectively 3 Tesla MRI with Gadolinium~ application visualize the various old and acute lesions. They serve as a biological marker in com- bination with standardised assessment of brain atrophy, black holes, etc. However, MRI with a stronger magnetic 7 Tesla field with better sensitivity gave hints on an on- going, acute inflammatory, smouldering process even with Gadolinium~ enhancing acute lesions in the brain and the spinal cord in progressive, so-called relapse free MS patients （Mtiller, 2009; Sinnecker et al., 2012）. Ad- ditionally, progress of MS is determined with subjective standardised clinical ratings （Sinnecker et al., 2012）. Both methods are used for the evaluation of the efficacy of relapse rate reducing drugs. These compounds, i.e., in- terferons, teriflunamide, glatiramer acetate, fingolimod, fumarate or monoclonal antibodies, preponderantly weaken the malfunction of the peripheral immune system in relapse remitting MS patients. These MS drugs share one common disadvantage. They do not stop progression or improve MS within a framework of a regenerative process. They do not enable reversal of symptoms, for in- stance functional deficits or spasticity （Mtiller, 2009）.

关键词： RGMa Biochemical indicators for neuronal regeneration during intrathecal triamcinolone application in multiple sclerosis EDSS

Modelling Hydrological Consequences of Climate Change—Progress and Challenges

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Advances in Atmospheric Sciences 2005年第6期22卷 789-797页

作者： Chong-yu XU Elin WIDEN sven HALLDIN Department of Geosciences University of Oslo P. O. Box 1047 Blindern N-0316 Oslo Norway Department of Earth Sciences Uppsala University Villavagen 16 S-75236 Uppsala Sweden Nanjing Institute of Geography and Limnology Chinese Academy of Sciences

The simulation of hydrological consequences of climate change has received increasing attention from the hydrology and land-surface modelling communities. There have been many studies of climate-change effects on hydrology and water resources which usually consist of three steps：（1） use of general circulation models （GCMs） to provide future global climate scenarios under the effect of increasing greenhouse gases, （2） use of downscaling techniques （both nested regional climate models, RCMs, and statistical methods） for ＂downscaling＂ the GCM output to the scales compatible with hydrological models, and （3） use of hydrologic models to simulate the effects of climate change on hydrological regimes at various scales. Great progress has been achieved in all three steps during the past few years, however, large uncertainties still exist in every stage of such study. This paper first reviews the present achievements in this field and then discusses the challenges for future studies of the hydrological impacts of climate change.

关键词： climate change water-resources assessment water balance regional scale hydrological models review

Stable Adult Growth but Reduced Asexual Fecundity in Marginopora vertebralis,under Global Climate Change Scenarios

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Journal of Earth Science 2022年第6期33卷 1400-1410页

作者： Claire E.Reymond Frances Patel sven Uthicke School of Earth Sciences China University of GeosciencesWuhan430074China School of Geosciences The University of SydneySydneyNSW2006Australia Australian Institute of Marine Science Townsville MCQld4810Australia

Large benthic foraminifera are an integral component of shallow-water tropical habitats and like many marine calcifiers,are susceptible to ocean acidification(OA)and ocean warming(OW).In particular,the prolific Symbiodiniaceae-bearing and high-magnesium calcite Marginopora vertebralis has a low threshold compared to several diatom-bearing and low-magnesium calcite *** this multi-year mesocosm experiment,we tested three RPC 8.5 climate change scenarios(i)present day,(ii)the year 2050,and(iii)*** enable a realistic epiphytic association,these experiments were uniquely conducted using natural carbonate substrate,living calcifying alga,and *** contrast to previous studies,we detected no reduction in surface-area growth under future climate conditions compared with present day *** terms of calcification,***’epiphytic association to primary producers(i.e.,calcifying algae and seagrasses)potentially ameliorates the effects of OA by buffering against declines in boundary layer pH during periods of photosynthesis(i.e.,CO_(2)removal).Importantly for population maintenance,we observed a strong reduction in asexual fecundity under the 2100 *** propose the additional energy needed to maintain growth might be one reason for drastically reduced asexual *** alternative explanation could be that the 2℃temperature increase interfered with the environmental synchronization that triggered asexual multiple *** conclude that the low levels of reproduction will reduce populations in a high CO_(2)environment and reduce a valuable source of CaCO_(3) sediment production.

关键词： mesocosm experiment ocean acidification ocean warming large benthic foraminifera carbonate production tropical reef asexual reproduction climate change

Counting and measuring particles sized from soot to pollen

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China Particuology 2007年第5期5卷 359-361页

作者： Martin Schmidt sven Schütz Leander Mlter Palas GmbH Greschbachstr. 3b76229 KarlsruheGermany

For number concentration measurements of superfine particles a condensation nucleus counter （CNC） is frequently used. The combination of a new CNC module with a white light aerosol spectrometer and a passive collector makes possible accurate time-resolved determination of particle number within the overall size range of 10 nm to 40 μm and at concentrations up to 10^5 particles/cm^3. With the aerosol spectrometer a high time-resolved particle size determination is also possible in the size range of 0.3-40 μm up to the same high number concentrations of 10^5 particles/cm^3.

关键词： CNC Particles Size

Conformance testing of FMI calling sequence for simulation environments

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International Journal of Modeling, Simulation, and Scientific Computing 2019年第2期10卷 156-183页

作者： Awad Mukbil Umut Durak sven Hartmann Clausthal University of Technology Department of Informatics Julius-Albert-Str.4 Clausthal-Zellefeld 38678Germany German Aerospace Center(DLR)Institute of Flight Systems Lilienthalplatz 7 Braunschweig 38108Germany

Exchanging simulation models is currently of utmost *** improve interoperability between suppliers and original equipment manufacturers(OEMs),the functional mock-up interface(FMI)is exchanged in a standard format called functional mock-up unit(FMU).Since its first release,many simulation tools took the initiative to support ***,since then,there have been many complaints stating that exchanging models via FMI does not work as stable as *** reason usually turned out to be the implementation of tool vendors that sometimes fail to comply with the standard *** paper introduces a methodology for testing FMI compliance of importing simulation tools using a set of reference *** standard defines the implementation of FMI functions calling sequence in a state ***,conformance testing(also called fault detection)from automata theory is utilized to produce reference FMUs based on the FMI state-machine.

关键词： FMI reference FMUs finite-state machine conformance testing

Software development processes in ocean system modeling

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International Journal of Modeling, Simulation, and Scientific Computing 2022年第2期13卷 47-69页

作者： Reiner Jung sven Gundlach Wilhelm Hasselbring Software Engineering Group Department of Computer Science Kiel UniversityKielGermany

Scientific modeling provides mathematical abstractions of real-world systems and builds software as implementations of these mathematical *** science is a multidisciplinary discipline developing scientific models and simulations as ocean sys-tem models that are an essential research *** software engineering and information systems research,modeling is also an essential *** particular,business process modeling for business process management and systems engineering is the activity of representing processes of an enterprise,so that the current process may be analyzed,improved and *** this paper,we employ process modeling for analyzing sci-entific software development in ocean science to advance the state in engineering of ocean system models and to better understand how ocean system models are developed and maintained in ocean *** interviewed domain experts in semi-structured inter-views,analyzed the results via thematic analysis,and modeled the results via the Busi-ness Process Modeling Notation(BPMN).The processes modeled as a result describe an aspired state of software development in the domain,which are often not(yet)*** enables existing processes in simulation-based system engineering to be improved with the help of these process models.

关键词： Scientific modeling software development processes process modeling the-matic analysis

Motility index measured by magnetic resonance enterography is associated with sex and mural thickness

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World Journal of Gastroenterology 2020年第36期26卷 5484-5497页

作者： sven Mansson Olle Ekberg Bodil Ohlsson Medical Radiation Physics Department of Translational MedicineLund UniversitySkåne University Hospital MalmöMalmö20502Sweden Department of Translational Medicine Diagnostic RadiologyLund UniversitySkåne University HospitalMalmö20502Sweden Department of Internal Medicine Skåne University HospitalLund UniversityMalmöS-20502Sweden

BACKGROUND Recently,a technique has been developed to use magnetic resonance enterography(MRE)for the evaluation of small bowel *** hypothesis was that assessment of the motility index(MI)should reflect differences in motility between clinical *** To aim of the present observational,cross-sectional study was to evaluate the use of the MI in daily clinical *** All consecutive patients aged 18-70 years who were referred for MRE at the Department of Radiology during a 2-year period were asked to *** volunteers were included as *** was prepared and conducted in accordance with clinical *** the day of examination,all the participants had to complete the visual analog scale for irritable bowel syndrome(IBS)and IBS-symptom severity *** of MI were calculated from dynamic MR *** was used to evaluate differences in MI between groups,classified as healthy,Crohn’s disease,ulcerative colitis,IBS,other assorted disorders and *** and linear regression were applied to the MI *** medical records were scrutinized for medical *** In all,224 examinations were included(inclusion prevalence 76.3%),with 22 controls and 202 *** was a significant difference in the MI of the jejunum(P=0.021)and terminal ileum(P=0.007)between the different *** MI was inversely associated with the mural thickness of the terminal ileum in men(P<0.001)and women(P=0.063)after adjustments,and tended to be lower in men than in women(P=0.056).Subjectively observed reduction of motility on MRI was accomplished by reduced MI of terminal ileum in men(P<0.001)and women(P=0.030).In women,diarrhea was inversely associated with the MI of the jejunum(P=0.029),and constipation was positively associated with the MI of the terminal ileum(P=0.039).CONCLUSION Although MIs differ across diseases,a lower MI of the terminal ileum is mainly associated with male sex and an increased mural thickness.S

关键词： Dysmotility Gastrointestinal symptoms Magnetic resonance enterography Motility index Mural thickness Small bowel