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journal of Rock Mechanics and Geotechnical Engineering 2017年第6期9卷 1112-1122页

作者： Rohola Hasanpour jürgen schmitt Yilmaz Ozcelik jamal Rostami Institute for Tunneling and Construction Management Ruhr-University Bochum Department of Civil Engineering Darmstadt University of Applied Science Department of Mining Engineering Hacettepe University Department of Mining Engineering Colorado School of Mines

Severe shield jamming events have been reported during excavation of Uluabat tunnel through adverse geological conditions, which resulted in several stoppages at advancing a single shielded tunnel boring machine(TBM). To study the jamming mechanism, three-dimensional(3D) simulation of the machine and surrounding ground was implemented using the finite difference code FLAC3D. Numerical analyses were performed for three sections along the tunnel with a higher risk for entrapment due to the combination of overburden and geological conditions. The computational results including longitudinal displacement contours and ground pressure profiles around the shield allow a better understanding of ground behavior within the excavation. Furthermore, they allow realistically assessing the impact of adverse geological conditions on shield jamming. The calculated thrust forces, which are required to move the machine forward, are in good agreement with field observations and measurements. It also proves that the numerical analysis can effectively be used for evaluating the effect of adverse geological environment on TBM entrapments and can be applied to prediction of loads on the shield and preestimating of the required thrust force during excavation through adverse ground conditions.

关键词： Single shielded tunnel boring machine(TBM) Numerical modeling Shield jamming Squeezing ground Uluabat tunnel

Short-Term Response of Soil Respiration to Addition of Chars:Impact of Fermentation Post-Processing and Mineral Nitrogen

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Pedosphere 2015年第5期25卷 761-769页

作者： Giacomo LANZA Stephan WIRTH Arthur GESSLER jrgen KERN Leibniz Institute for Agricultural Engineering Leibniz Centre for Agricultural Landscape Research (ZALF) Swiss Federal Institute for Forest Snow and Landscape Research WSL

The biodegradability of chars derived from pyrolysis and hydrothermal carbonisation(HTC) was studied in short-term dynamic incubation experiments under controlled conditions. Carbon dioxide C(CO2) emissions from soil-char mixtures in combination with solid digestate or mineral nitrogen(N) fertiliser were measured in dynamic chambers for 10 d. Compared to the original material(maize straw), pyrolysis and HTC chars showed significantly lower CO2 emissions and slower decay dynamics; and compared to the soil control, HTC char increased soil respiration to a significant extent, while pyrolysis char did not. The addition of mineral N resulted in a delayed respiration dynamics for HTC char, while the addition of digestate resulted in an increase in the respired CO2 for pyrolysis char and a decrease for HTC char. For the first time, a peculiar two-stage decay kinetics was observed for HTC char,indicating a highly inhomogeneous substrate consisting at least of two C pools.

关键词： biodegradability CO2 emission decay dynamics hydrothermal carbonisation char pyrolysis char

Magnetic labeling of primary murine monocytes using very small superparamagnetic iron oxide nanoparticles

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Neural Regeneration Research 2022年第10期17卷 2311-2315页

作者： Martin Pohland Christoph Pohland jürgen Kiwit jana Glumm Institute of Cell Biology and Neurobiology Center for AnatomyCharité-Universitätsmedizin BerlinBerlinGermany Department of Neurosurgery Helios Klinikum Berlin BuchBerlinGermany

Due to their very small size,nanoparticles can interact with all cells in the central nervous *** of the most promising nanoparticle subgroups are very small superparamagnetic iron oxide nanoparticles(VSOP)that are citrate coated for electrostatic *** determine their influence on murine blood-derived monocytes,which easily enter the injured central nervous system,we applied VSOP and carboxydextran-coated superparamagnetic iron oxide nanoparticles(Resovist).We assessed their impact on the viability,cytokine,and chemokine secretion,as well as iron uptake of murine blood-derived *** found that(1)the monocytes accumulated VSOP and Resovist,(2)this uptake seemed to be nanoparticle-and time-dependent,(3)the decrease of monocytes viability was treatment-related,(4)VSOP and Resovist incubation did not alter cytokine homeostasis,and(5)overall a 6-hour treatment with 0.75 mM VSOP-R1 was probably sufficient to effectively label monocytes for future *** homeostasis is not altered,it is safe to label blood-derived monocles with *** labeled monocytes can be used to study injured central nervous system sites further,for example with drug-carrying VSOP.

关键词： CD11b,cytokine Ferucarbotran Mac1 MPS MRI Resovist superparamagnetic iron oxide nanoparticles(SPIO) very small superparamagnetic iron oxide nanoparticles(VSOP) viability

Probabilistic description of extreme oscillations and reliability analysis in rolling motion under stochastic excitation

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Science China(Technological Sciences) 2023年第9期66卷 2586-2596页

作者： ZHAO Dan LI YongGe XU Yong LIU Qi KURTHS jürgen school of Mathematics and Statistics Northwestern Polytechnical UniversityXi’an 710072China MOE Key Laboratory for Complexity Science in Aerospace Northwestern Polytechnical UniversityXi’an 710072China Potsdam Institute for Climate Impact Research Potsdam 14412Germany Department of Physics Humboldt University BerlinBerlin 12489Germany

Large-amplitude rolling motions, also regarded as extreme oscillations, are a great threat to marine navigation, which may lead to capsizing in ship motion. Therefore, it is important to quantify extreme oscillations, assess reliability of ship systems, and establish a suitable indicator to characterize extreme oscillations in ship systems. In this work, extreme events are investigated in a ship model considering a complex ocean environment, described by a single-degree-of-freedom nonlinear system with stochastic harmonic excitation and colored Gaussian noise. The stationary probability density function(PDF) of the system is derived through a probabilistic decomposition-synthesis method. Based on this, we infer the classical damage rate of the system. Furthermore, a new indicator, independent of the PDF, is proposed to quantify the damage related only to the fourth-order moment of the system and the threshold for extreme events. It is more universal and easier to determine as compared with the classical damage rate. A large damping ratio, a large noise intensity, or a short correlation time can reduce the damage rate and the value of the *** findings provide new insights and theoretical guidance to avoid extreme oscillations and assess the reliability of practical ship movements.

关键词： rolling motion colored noise extreme oscillations reliability probabilistic decomposition-synthesis method

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Spectral Gap of the Largest Eigenvalue of the Normalized Graph Laplacian

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Communications in Mathematics and Statistics 2022年第3期10卷 371-381页

作者： jürgen jost Raffaella Mulas Florentin Münch Max Planck Institute for Mathematics in the Sciences LeipzigGermany

We offer a new method for proving that the maxima eigenvalue of the normalized graph Laplacian of a graph with n vertices is at least n+1/n−1 provided the graph is not complete and that equality is attained if and only if the complement graph is a single edge or a complete bipartite graph with both parts of size n−1/*** the same method,we also prove a new lower bound to the largest eigenvalue in terms of the minimum vertex degree,provided this is at most n−1/2.

关键词： Spectral graph theory Normalized Laplacian Largest eigenvalue Sharp bounds

Interpretation and compensation of backlash error data in machine centers for intelligent predictive maintenance using ANNs

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Advances in Manufacturing 2015年第2期3卷 97-104页

作者： Ke-Sheng Wang Zhe Li jФrgen Braaten Quan Yu Knowledge Discovery Laboratory Department of Production and Quality EngineeringNorwegian University of Science and Technology Key Laboratory of Intelligent Manufacturing and Robotics Shanghai University

It is especially significant for a manufacturing company to select a proper maintenance policy because maintenance impacts not only on economy, reliability and availability but also on personnel safety. This article re- ports on research in the backlash error data interpretation and compensation for intelligent predictive maintenance in machine centers based on artificial neural networks （ANNs）. The backlash error, measurement system and prediction methods are analyzed in detail. The result indicates that it is possible to predict and compensate for the backlash error in both forward and backward directions in machine centers.

关键词： Backlash error Artificial neural network(ANN) Machine centers Predictive maintenance

Gastroenteric tube feeding: Techniques, problems and solutions

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World journal of Gastroenterology 2014年第26期20卷 8505-8524页

作者： Irina Blumenstein Yogesh M Shastri jürgen Stein Department of Gastroenterology and Clinical Nutrition Johann Wolfgang Goethe University Clinic Gastroenterology and Clinical Nutrition Hospital Sachsenhausen Crohn Colitis Clinical Research Center RheinMain

Gastroenteric tube feeding plays a major role in the management of patients with poor voluntary intake,chronic neurological or mechanical dysphagia or gut dysfunction,and patients who are critically ***,despite the benefits and widespread use of enteral tube feeding,some patients experience *** review aims to discuss and compare current knowledge regarding the clinical application of enteral tube feeding,together with associated complications and special *** conducted an extensive literature search on PubMed,Embase and Medline using index terms relating to enteral access,enteral feeding/nutrition,tube feeding,percutaneous endoscopic gastrostomy/jejunostomy,endoscopic nasoenteric tube,nasogastric tube,and refeeding *** literature showed common routes of enteral access to include nasoenteral tube,gastrostomy and jejunostomy,while complications fall into four major categories:mechanical,e.g.,tube blockage or removal;gastrointestinal,e.g.,diarrhea;infectious e.g.,aspiration pneumonia,tube site infection;and metabolic,e.g.,refeeding syndrome,*** the type and frequency of complications arising from tube feeding vary considerably according to the chosen access route,gastrointestinal complications are without doubt the most *** associated with enteral tube feeding can be reduced by careful observance of guidelines,including those related to food composition,administration rate,portion size,food temperature and patient supervision.

关键词： Enteral tube feeding Percutaneous endoscopic gastrostomy Refeeding syndrome Enteral nutrition Buried bumper syndrome Nasoenteral tubes Colocutaneous fistulae

CONVErgenCE OF ADAPTIVE EDGE ELEMENT METHODS FOR THE 3D EDDY CURRENTS EQUATIONS

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journal of Computational Mathematics 2009年第5期27卷 657-676页

作者： R.H.W.Hoppe j.schberl Institut fur Mathematik Universitat AugsburgD-86159AugsburgGermanyand Department of MathematicsUniversity of HoustonHoustonTX 77204-3008USA Dept.for Mathematics CCES(Center for Computational Engineering Science) RWTH AachenD-52074 AachenGermany

We consider an Adaptive Edge Finite Element Method （AEFEM） for the 3D eddy currents equations with variable coefficients using a residual-type a posteriori error estimator. Both the components of the estimator and certain oscillation terms, due to the occurrence of the variable coefficients, have to be controlled properly within the adaptive loop which is taken care of by appropriate bulk criteria. Convergence of the AEFEM in terms of reductions of the energy norm of the discretization error and of the oscillations is shown. Numerical results are given to illustrate the performance of the AEFEM.

关键词： Adaptive edge elements 3D eddy currents equations Convergence analysis,Error and oscillation reduction Residual type a posteriori error estimates.

Epidermal Patterning Genes Impose Non‐cell Autonomous Cell Size Determination and have Additional Roles in Root Meristem Size Control

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journal of Integrative Plant Biology 2013年第9期55卷 864-875页

作者： Christian Lfke Kai Dünser jürgen Kleine‐Vehn Department of Applied Genetics and Cell Biology Vienna Institute of Biotechnology (VIBT) University of Natural Resources and Life Sciences Vienna (BOKU)Muthgasse 18 1190 Vienna Austria

The regulation of cellular growth is of vital importance for embryonic and postembryonic patterning. Growth regulation in the epidermis has importance for organ growth rates in roots and shoots, proposing epidermal cells as an interesting model for cellular growth regulation. Here we assessed whether the root epidermis is a suitable model system to address cell size determination. In Arabidopsis thaliana L., root epidermal cells are regularly spaced in neighbouring tricho-（root hair） and atrichoblast （non-hair） cells, showing already distinct cell size regulation in the root meristem. We determined cell sizes in the root meristem and at the onset of cellular elongation, revealing that not only division rates but also cellular shape is distinct in tricho-and atrichoblasts. Intriguingly, epidermal-patterning mutants, failing to define differential vacuolization in neighbouring epidermal cell files, also display non-differential growth. Using these epidermal-patterning mutants, we show that polarized growth behaviour of epidermal tricho-and atrichoblast is interdependent, suggesting non-cell autonomous signals to integrate tissue expansion. Besides the interweaved cell-type-dependent growth mechanism, we reveal an additional role for epidermal patterning genes in root meristem size and organ growth regulation. We conclude that epidermal cells represent a suitable model system to study cell size determination and interdependent tissue growth.

关键词： Atrichobtast cell size determination trichoblast,

Path integral solutions for n-dimensional stochastic differential equations underα-stable Lévy excitation

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Theoretical & Applied Mechanics Letters 2023年第2期13卷 98-112页

作者： Wanrong Zan Yong Xu jürgen Kurths school of Mathematics Northwest UniversityXi’an710127China Department of Applied Mathematics Northwestern Polytechnical UniversityXi’an710129China MIIT key Laboratory of Dynamics and Control of Complex Systems Northwestern Polytechnical UniversityXi’an710129China Potsdam Institute for Climate Impact Research Potsdam14412Germany Department of Physics Humboldt University of BerlinBerlin12489Germany

In this paper,the path integral solutions for a general n-dimensional stochastic differential equa-tions(SDEs)withα-stable Lévy noise are derived and ***,the governing equations for the solutions of n-dimensional SDEs under the excitation ofα-stable Lévy noise are obtained through the characteristic function of stochastic ***,the short-time transition probability density func-tion of the path integral solution is derived based on the Chapman-Kolmogorov-Smoluchowski(CKS)equation and the characteristic function,and its correctness is demonstrated by proving that it satis-fies the governing equation of the solution of the SDE,which is also called the Fokker-Planck-Kolmogorov ***,illustrative examples are numerically considered for highlighting the feasibility of the proposed path integral method,and the pertinent Monte Carlo solution is also calculated to show its correctness and effectiveness.

关键词： Path integral method α-stable Lévy noise Monte carlo method Fokker-Planck-Kolmogorov equation