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Using machine learning models to explore the solution space of large nonlinear systems underlying flowsheet simulations with constraints

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Frontiers of Chemical Science and Engineering 2022年第2期16卷 183-197页

作者： Patrick Otto Ludl Raoul Heese johannes Höller Norbert Asprion Michael Bortz Fraunhofer ITWM Optimization Department Kaiserslautern 67663Germany Chemical and Process Engineering BASF SE Ludwigshafen 67056Germany

Flowsheet simulations of chemical processes on an industrial scale require the solution of large systems of nonlinear equations,so that solvability becomes a practical *** constraints from technical,economic,environmental,and safety considerations may further limit the feasible solution space beyond the convergence requirement.A priori,the design variable domains for which a simulation converges and fulfills the imposed constraints are usually unknown and it can become very time-consuming to distinguish feasible from infeasible design variable choices by simply running the simulation for each *** support the exploration of the design variable space for such scenarios,an adaptive sampling technique based on machine learning models has recently been ***,that approach only considers the exploration of the convergent domain and ignores additional *** this paper,we present an improvement which particularly takes the fulfillment of constraints into *** successfully apply the proposed algorithm to a toy example in up to 20 dimensions and to an industrially relevant flowsheet simulation.

关键词： machine learning flowsheet simulations constraints exploration

Roughness Measurements with Polychromatic Speckles on Tilted Surfaces

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Nanomanufacturing and Metrology 2021年第4期4卷 237-246页

作者： johannes Stempin Andreas Tausendfreund Dirk Stobener Andreas Fischer Bremen Institute for Metrology Automation and Quality ScienceUniversity of BremenLinzer Str.1328359 BremenGermany

Surface light scattering enables contactless and fast measurements of surface roughness.A surface inclination alters the direction of the scattering beam and thus the measured surface roughness is calculated from the detected intensity ***,an accurate sensor-surface alignment is *** order to achieve tilt-independent roughness measurements,a model-based evaluation approach for polychromatic speckle patterns is *** evaluating the shape of the superposed speckles,which occur for polychromatic illumination,with regard to the distance to the scattering centre,surfaces with an Sa roughness value in the range of 0.8-3.2μm are *** investigations demonstrate that the influence of a surface tilt up to±1.25°on the roughness measurement is reduced by 90%.As a result,the robustness of the polychromatic speckle roughness measurement is improved,which allows to speed up the adjustment of the measurement system or the surface sample,respectively.

关键词： Surface roughness Polychromatic light scattering Surface tilting In-process measurement

Giant anomalous Hall and Nernst effect in magnetic cubic Heusler compounds

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npj Computational Materials 2020年第1期6卷 1014-1021页

作者： Jonathan Noky Yang Zhang johannes Gooth Claudia Felser Yan Sun Max Planck Institute for Chemical Physics of Solids D-01187 DresdenGermany Massachusetts Institute of Technology CambridgeMA 02139USA

The interplay of magnetism and topology opens up the possibility for exotic linear response effects,such as the anomalous Hall effect and the anomalous Nernst effect,which can be strongly enhanced by designing a large Berry curvature in the electronic *** Heusler compounds are a promising class of materials for this purpose because they are versatile,show magnetism,and their electronic structure hosts strong topological ***,we provide a comprehensive study of the intrinsic anomalous transport for magnetic cubic full Heusler compounds and we illustrate that several Heusler compounds outperform the best so far reported *** results reveal the importance of symmetries,especially mirror planes,in combination with magnetism for giant anomalous Hall and Nernst effects,which should be valid in general for linear responses(spin Hall effect,spin orbital torque,etc.)dominated by intrinsic contributions.

关键词： structure Nernst cubic

Effects of rice straw on the cell viability, photosynthesis, and growth of Microcystis aeruginosa

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Chinese Journal of Oceanology and Limnology 2014年第1期32卷 120-129页

作者：苏文 johannes A.HAGSTR?M 贾育红卢亚萍孔繁翔 State Key Laboratory of Lake & Environment Science Nanjing Institute of Geography and LimnologyChinese Academy of Sciences University of Chinese Academy of Sciences Ecology and Evolution in Microbial Model Systems EEMiSSchool of Natural SciencesLinnaeus University

Rice straw is supposed to be an environment-friendly biomaterial for inhibiting the growth of harmful blooms of the cyanobacterium Microcystis aeruginosa. However, its potential mechanism is not well known. To explore this mechanism, the growth, cell viability(esterase activity, membrane potential, and membrane integrity), photosynthesis, and cell size of M. aeruginosa were determined using fl ow cytometry and Phyto-PAM after exposure to rice straw extracts(RSE). The results show that doses from 2.0 to 10.0 g/L of RSE effi ciently inhibited the alga for 15 days, while the physiologic and morphologic responses of the cyanobacteria were time-dependent. RSE interfered with the cell membrane potential, cell size, and in vivo chlorophyll- a fl uorescence on the fi rst day. After 7 days of exposure, RSE was transported into the cytosol, which disrupted enzyme activity and photosynthesis. The cyanobacteria then started to repair its physiology(enzyme activity, photosynthesis) and remained viable, suggesting that rice straw act as an algistatic agent.

关键词： esterase activity membrane potential Phyto-PAM rice straw Microcystis flow cytometry

Machine-learning driven global optimization of surface adsorbate geometries

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npj Computational Materials 2023年第1期9卷 1196-1203页

作者： Hyunwook Jung Lena Sauerland Sina Stocker Karsten Reuter johannes T.Margraf Fritz-Haber-Institut der Max-Planck-Gesellschaft Faradayweg 4-6D-14195 BerlinGermany

The adsorption energies of molecular adsorbates on catalyst surfaces are key descriptors in computational catalysis *** the relatively large reaction intermediates frequently encountered,e.g.,in syngas conversion,a multitude of possible binding motifs leads to complex potential energy surfaces(PES),*** implies that finding the optimal structure is a difficult global optimization problem,which leads to significant uncertainty about the stability of many *** tackle this issue,we present a global optimization protocol for surface adsorbate geometries which trains a surrogate machine learning potential *** approach is applicable to arbitrary surface models and adsorbates and minimizes both human intervention and the number of required DFT calculations by iteratively updating the training set with configurations explored by the *** demonstrate the efficiency of this approach for a diverse set of adsorbates on the Rh(111)and(211)surfaces.

关键词： optimization global implies

Scientific geodata infrastructures: challenges, approaches and directions

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International Journal of Digital Earth 2014年第7期7卷 613-633页

作者： Lars Bernard Stephan Mas Matthias Muller Christin Henzen johannes Brauner Department of Geosciences Faculty of Environmental SciencesTechnische Universitat DresdenDresdenGermany

Based on various experiences in developing Geodata Infrastructures(GDIs)for scientific applications,this article proposes the concept of a Scientific GDI that can be used by scientists in environmental and earth sciences to share and disseminate their research results and related analysis *** GDI is understood as an approach to tackle the science case in Digital Earth and to further enhance e-science for environmental *** Scientific GDI to support the research community in efficiently exchanging data and methods related to the various scientific disciplines forming the basis of environmental studies poses numerous challenges on today’s GDI *** paper summarizes requirements and recommendations on the publication of scientific geospatial data and on functionalities to be provided in Scientific *** practices and open issues for governance and policies of a Scientific GDI are discussed and are concluded by deriving a research agenda for the next decade.

关键词： scientific geodata infrastructure sharing environmental models geospatial cyberinfrastructure e-science spatial data infrastructure

The Combinatorial Approach to Asymmetric Hydrogenation: More Miles out of Monophos

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复旦学报（自然科学版） 2005年第5期44卷 829-830页

作者： johannes G. de Vries DSM Research DSM Pharma Chemicals-Advanced Synthesis Catalysis & Development P.O. Box 18 6160 MD Geleen The Netherlands.

In custom manufacturing time-to-market is of overriding importance. Thus, asymmetric hydrogenation will be applied only if an appropriate catalyst can be found in a very short period of time. For this reason we have build up a full-scale capability for High Throughput Experimentation, encompassing several robot systems. As ligand synthesis was the last remaining barrier we have explored, together with the University of Groningen, the use of simple monodentate ligands, such as MonoPhosTM. These ligands can be synthesised in two chemical steps, from BINOL, PCl3 and an ***, very high enantioselectivities can be obtained in the asymmetric hydrogenation of α-and β-dehydro-amino acids and esters, aromatic enamides, itaconic acid and ester[1]. See Scheme 1 and 2(at page 830).

关键词：加氢催化同质催化剂铑氨基磷酸脂

Contact tracing-Old models and new challenges

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Infectious Disease Modelling 2021年第1期6卷 222-231页

作者： johannes Müller Mirjam Kretzschmar Mathematical Institute Technical University of MunichBoltzmannstr.385748GarchingGermany Institute for Computational Biology Helmholtz Center Munich85764NeuherbergGermany Julius Center for Health Sciences and Primary Care University Medical Center UtrechtUtrecht UniversityHeidelberglaan 1003584CXUtrechtthe Netherlands

Contact tracing is an effective method to control emerging infectious *** the 1980’s,modellers are developing a consistent theory for contact tracing,with the aim to find effective and efficient implementations,and to assess the effects of contact tracing on the spread of an infectious *** the progress made in the area,there remain important open *** addition,technological developments,especially in the field of molecular biology(genetic sequencing of pathogens)and modern communication(digital contact tracing),have posed new challenges for the modelling *** the present paper,we discuss modelling approaches for contact tracing and identify some of the current challenges for the field.

关键词： Contact tracing Mathematical models

Effect of bed load supply on sediment transport in mountain streams

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International Journal of Sediment Research 2017年第2期32卷 240-252页

作者： johannes Kammerlander Bernhard Gems Daniel Kβler Markus Aufleger Unit of Hydraulic Engineering University of Innsbruck Austrian Research Centre for Forests Department of Natural Hazards 3. BERNARD Ingenieure ZT GmbH

Mountain streams with their tributary torrents build the upper part of the fluvial *** are important regarding the transfer of sediment from headwaters to lower *** are typically steep with wide grain size distributions,ranging from fine sand up to large boulders,and a stabilized bed *** streams often are supply-limited with respect to mobile bed load,which needs to be addressed when bed load transport equations are applied to such *** better understand supply limitation,laboratory experiments highlighting the effect of bed load supply on incipient motion and bed load transport rate are *** tests were done in which fine bed load was supplied to a previously armored channel bed,with flow conditions ranging from one-third to twice the critical discharge for the bed *** flows not exceeding the critical discharge,the time series of the bed load transport rate at the downstream model boundary featured consistent patterns which are attributed to distinct phases:(i) a temporal lag,(ii) an equilibrium state,and(iii) a post-supply *** load transport occurred even at flows distinctly below that for incipient motion of the bed ***,with the mass of total bed load outflow approaching the supply amount,the mass did not exclusively consist of supplied *** coarser the supplied bed load,the more sediment was mobilized from the bed *** higher flows,processes *** bed load outflow exceeded the supply amount and the break-up of the armor layer caused a refining of the bed surface.

关键词： Bed load transport Bed load supply Mountain stream Experimental modeling