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Optimizing selective withdrawal strategies to mitigate hypoxia under water-level reduction in Germany’s largest drinking water reservoir

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Journal of Environmental Sciences 2024年第12期146卷 127-139页

作者： Chenxi Mi Karsten Rinke tom Shatwell Helmholtz Centre for Environmental Research Department of Lake ResearchMagdeburg 39114Germany College of Water Conservancy Shenyang Agricultural UniversityShenyang 110866China

Water-level reduction frequently occurs in deep reservoirs,but its effect on dissolved oxygen concentration is not well *** this study we used a well-established water qual-itymodel to illustrate effects of water level dynamics on oxygen concentration in Rappbode Reservoir,*** then systematically elucidated the potential of selectivewithdrawal to control hypoxia under changing water *** results documented a gradual decrease of hypolimnetic oxygen concentration under decreasing water level,and hypoxia occurred when the initial level was lower than 410 m a.s.l(71 m relative to the reservoir bottom).We also suggested that changes of hypoxic region,under increasing hypolimnetic withdrawal discharge,followed a unimodal trajectory with themaximum hypoxic area projected under the discharge between 3 m^(3)/sec and 4 m^(3)/***,our results illustrated the extent of hypoxia was most effectively inhibited if the withdrawal strategy was applied at the end of stratification with the outlet elevation at the deepest part of the ***,hy-poxia can be totally avoided under a hybrid elevation withdrawal strategy using surface withdrawal during early and mid stratification,and deep withdrawal at the end of *** further confirmed the decisive role of thermal structure in the formation of hypoxia under water-level reduction and withdrawal *** believe the conclusions from this study can be applied to many deep waters in the temperate zone,and the results should guide stakeholders to mitigate negative impacts of hypoxia on aquatic ecosystems.

关键词： Hypoxia Water-level reduction Hypolimnetic water withdrawal Stratification phenology Water quality simulation Sediment oxygen demand

Hydrogen energy carriers

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Journal of Energy Chemistry 2023年第2期77卷 119-121,I0004页

作者： tom Autrey Ping Chen Pacific Northwest National Laboratories Physical and Computational Science DirectorateRichlandWA99352USA Dalian Institute of Chemical Physics Chinese Academy of SciencesDalian 116023LiaoningChina

The versatility of hydrogen will provide opportunities in large scale,long duration energy storage,and the decarbonization of *** energy carriers are molecules and materials that store hydrogen at higher volumetric de... 详细信息

关键词： hydrogen energy Hydrogen

Multispecies coalescent and its applications to infer species phylogenies and cross-species gene flow

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National Science Review 2021年第12期8卷 86-103页

作者： Xiyun Jiao tomá■ Flouri Ziheng Yang Department of Genetics Evolution and EnvironmentUniversity College London Department of Statistics and Data Science Southern University of Science and Technology

Multispecies coalescent(MSC) is the extension of the single-population coalescent model to multiple species. It integrates the phylogenetic process of species divergences and the population genetic process of coalescent, and provides a powerful framework for a number of inference problems using genomic sequence data from multiple species, including estimation of species divergence times and population sizes,estimation of species trees accommodating discordant gene trees, inference of cross-species gene flow and species delimitation. In this review, we introduce the major features of the MSC model, discuss full-likelihood and heuristic methods of species tree estimation and summarize recent methodological advances in inference of cross-species gene flow. We discuss the statistical and computational challenges in the field and research directions where breakthroughs may be likely in the next few years.

关键词： anomaly zone BPP deep coalescence gene flow Markov chain Monte Carlo multispecies coalescent species tree

Comments on"Vitamin Pharmacogenomics:New Insight into Individual Differences in Diseases and Drug Responses"

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Genomics, Proteomics & Bioinformatics 2017年第6期15卷 405-406页

作者： tom Greenfield International College of Generative Medicine CanterburyKent CTI 1BLUnited Kingdom

Dear Editor, I would like to offer some comments on the excellent article by Hai-Yan He and colleagues published in Genomics, Proteomics ＆ Bioinformatics on 1st April 2017 [1]. The authors include, in the list of genetic polymorphisms that have an effect on vita- mins, the low concentrations of cellular and plasma vitamin B12 in GG carriers of SNP rs602662 （772 G 〉 A） in the gene encoding fucosyltransferase 2 （FUT2）.

关键词： Comments on "Vitamin Pharmacogenomics New Insight into Individual Differences Diseases and Drug Responses"

Enhancing the efectiveness of film cooling

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航空动力学报 2007年第4期22卷 531-539页

作者： tom I-P Shih Sangkwon Na Department of Aerospace Engineering Iowa State University Ames Iowa 50011 U. S. A

Advanced gas turbine stages are designed to operate at increasingly higher inlet temperatures to increase thermal efficiency and specific power *** maintain durability and reasonable life,film cooling is needed in addition to internal cooling,especially for the first *** cooling lowers material temperature by forced convection inside film-cooling holes and by forming a layer of coolant about component surfaces to insulate them from the hot ***,each cooling jet forms a pair of counter-rotating vortices that entrains hot gas and causes the film-cooling jet to lift off from the surface that it is intended to *** paper gives an overview of efforts to enhance the effectiveness of *** paper also describes two new design *** design concept seeks to minimize the entrainment of hot gases underneath of film-cooling jets by using flow-aligned *** other design concept shifts the interaction between the approaching hot gas and the cooling jet to occur further above the surface by using an upstream *** both design concepts,computational fluid dynamics results are presented to examine their usefulness in enhancing film-cooling effectivenes

关键词：航空动力推进系统薄雾冷却冷却效率燃气轮机流体动力学

Correlation between MEG and BOLD fMRI signals induced by visual flicker stimuli

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仪器仪表学报 2007年第4期28卷 577-582页

作者： Chu Renxin Holroyd tom Duyn Jeff Department of Radiology Harvard Medical School Boston Massachusetts USA MEG Core Facility National Institute of Mental Health National Institutes of Health Bethesda Maryland USA Advanced MRI Section LFMI National Institute of Neurological Disorders and Stroke National Institutes of Health Bethesda Maryland USA

The goal of this work was to investigate how the MEG signal amplitude correlates with that of BOLD fMRI. To investigate the correlation between fMRI and macroscopic electrical activity, BOLD fMRI and MEG was performed on the same subjects (n=5). A visual flicker stimulus of varying temporal frequency was used to elicit neural responses in early visual areas. A strong similarity was observed in frequency tuning curves between both modalities. Although, averaged over subjects, the BOLD tuning curve was somewhat broader than MEG, both BOLD and MEG had maxima at a flicker frequency of 10 Hz. Also, we measured the first and second harmonic components as the stimuli frequency by MEG. In the low stimuli frequency (less than 6 Hz), the second harmonic has comparable amplitude with the first harmonic, which implies that neural frequency response is nonlinear and has more nonlinear components in low frequency than in high frequency.

关键词：视频 fMRI MEG 信号

Damping of Pressure Pulsations in Mobile Hydraulic Applications by the Use of Closed Cell Cellular Rubbers Integrated into a Vane Pump

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Journal of Bionic Engineering 2017年第4期14卷 791-803页

作者： David Bach tom Masselter Thomas Speck Plant Biomechanics Group Freiburg Botanic Garden Faculty of Biology University of Freiburg Schginzlestr. 1 79104 Freiburg Germany Freiburg Materials Research Center (FMF) Stefan-Meier-StraBe 21 79104 Freiburg Germany Competence Networks Biomimetic and BIOKON e. V. Schainzlestr. 1 79104 Freiburg Germany

The present study evaluates the potential of a bio-inspired pulsation damper in a vane pump used in mobile hydraulic ap- plications. Pressure pulsations caused by such positive displacement pumps can lead to malfunctions and noise in a hydraulic system. A common measure to reduce pressure pulsations is the integration of pressure pulsation dampers downstream of the pump. This type of damping measure can also be found in biology as e.g. in the human blood circulatory system. Such working principles found in living organisms offer a high potential for a biomimetic transfer into technical applications. The newly developed bio-inspired damper consists of cellular rubbers with non-linear viscoelastic material properties. In order to evaluate the new damping method, pressure pulsations were measured at two different back pressures and at a wide engine speed range of the vane pump. For further assessment, different setups, varying the stiffness of the cellular rubber materials and the damper volume, were tested. Within the tested back pressures, the pressure pulsations could be reduced by up to 40%. The developed integrated pulsation damper offers a high potential to dampen pressure pulsations of positive displacement pumps used in mobile hydraulic applications ooeratin~ below 10 bar.

关键词： pressure pulsations pressure ripple vane pump bio-inspired pulsation damping cellular rubbers flexible foams

Plants and Animals as Concept Generators for the Development of Biomimetic Cable Entry Systems

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Journal of Bionic Engineering 2008年第2期5卷 167-173页

作者： tom Masselter Uwe Scharf Thomas Speck Plant Biomechanics Group Botanic Garden of the University Freiburg Rittal GmbH & Co.KG Auf dem SttzelbergHerborn D-35745Germany

Many animals and plants have high potential to serve as concept generators for developing biomimetic materials and structures. We present some ideas based on structural and functional properties of plants and animals that led to the development of two types ofbiomimetic cable entry systems. Those systems have been realized on the level of functional demonstrators.

关键词： bionics biomimetics cable entry stents folding structures

Micromechanical modeling of polycrystalline high manganese austenitic steel subjected to abrasive contact

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Friction 2020年第3期8卷 626-642页

作者： Matti LINDROOS Anssi LA UKK ANEN tom ANDERSSON VTT Lifecycle Solutions Tampere 33720Finland

This study focuses on microstructural and micromechanical modeling of abrasive sliding contacts of wear-resistant Hadfield steel.3 D finite element representation of the microstructure was employed with a crystal plasticity model including dislocation slip,deformation twinning,and their *** results showed that deformation twinning interacting with dislocations had a key role in the surface hardening of the material,and it was also important for the early hardening process of the sub-surface grains beyond the heavily distorted surface *** effects of grain orientation and microstructural features were discussed and analyzed according to the micromechanical model to give a perspective to the anisotropy of the material and the feasibility of using micromechanics in virtual material design.

关键词： crystal plasticity micromechanical modeling of abrasion austenitic manganese steel deformation twinning