检索结果-南通市图书馆

International Journal of Extreme Manufacturing 2023年第1期5卷 193-200页

作者： Pierre Balage John Lopez Guillaume Bonamis clemens hönninger Inka Manek-hönninger Universitéde Bordeaux-CNRS-CEA CELIA UMR 510733405 TalenceFrance Amplitude Citéde la Photonique11 Avenue de Canteranne33600 PessacFrance

We report novel results on top-down percussion drilling in different glasses with femtosecond laser *** to this particular regime of light–matter interaction,combining non-linear absorption and thermal cumulative effects,we obtained crack-free holes of aspect ratios exceeding 30 in sodalime and 70 in fused *** results are discussed in terms of inner wall morphology,aspect ratio and drilling speed.

关键词： femtosecond laser glass Ghz-bursts percussion drilling

(Not) an elementary question:how to mobilize the iron in the wall?

在线全文

学校读者我要写书评

暂无评论

Molecular Plant 2021年第10期14卷 1610-1611页

作者： Stephan clemens Department of Plant Physiology and Faculty of Life Sciences:Food Nutrition and HealthUniversity of BayreuthUniversitätsstrasse 3095440 BayreuthGermany

Photosynthesis,respiration,and countless other processes are dependent on proteins that carry iron(Fe)as an essential *** Fe was recruited for biological functions early in evolution,it was an available *** Earth's at... 详细信息

关键词： element. elementary sulfide

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Roots dOdge streSs

Molecular Plant 2023年第12期16卷 1885-1886页

作者： Stephan clemens Department of Plant Physiology University of BayreuthUniversitatsstrasse 3095440BayreuthGermany

A hallmark of plant development is *** system architecture modulation in response to fluctuations of nutrient and water supply is a case in point(Giehl et al.,2014).The formation and length of lateral roots or the density of root hairs are strongly influenced by the availability of macro-and *** actively forage for mineral-rich patches in the typically heterogeneous soil environment and adjust their development systemically to increase the surface for nutrient ***,the opposite can happen as well.A recent study by Wang et al.(2023)convincingly demonstrated an active avoidance of unfavorable conditions by rice *** the seminal root of rice seedlings was placed between two agar blocks,one of them containing cations at toxic concentrations,adventitious roots developed only on the non-stress side,while development on the stress side was arrested(Figure 1).Besides,far more lateral roots were formed than in the absence of asymmetrically applied *** a while,this resulted in a total root biomass equivalent to that of control *** roots,in other words,had successfully shifted away from the stressful environment.

关键词： soil roots Figure

Dynamic stress concentration in an infinitely long cylindrical cavity due to a point spherical source embedded within a fluid-saturated poroelastic formation of infinite extent

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 139-156页

作者： h.hOSSEINI O.BALILAShAKI Department of Mechanical Engineering Faculty of EngineeringGolestan University

The effects of a harmonically exciting monopole source on an infinitely long cylindrical cavity embedded entirely within a fluid-saturated poroelastic formation of infinite extent are examined theoretically. It is assumed that the source is located outside the cavity at a specified distance from the borehole axis. The magnitudes of the hoop and radial stresses beside the pore pressures exerted on the interface and inside the porous medium surrounding the borehole are calculated and discussed. Biot's poroelastic modeling along with three types of boundary conditions for the cylindrical interface including the ideal fluid, empty borehole, and rigid inclusion with a hard boundary is employed for the analysis. Utilizing a proper translational addition theorem for expressing the incident spherical wave in terms of cylindrical wave expansions, the proposed boundary conditions at the interface are satisfied. Stresses are formulated by means of wave potential functions in a three-dimensional(3D) manner. The effects of the frequency and the radial distance between the source and borehole on the induced stresses are examined for the first cylindrical modes over frequency spectra. Two permeability conditions for the interface and three types of soils for the porous formation are considered throughout the analysis. To give an overall outline of the study, a numerical example is presented. The results clearly indicate that the distance is a key parameter and has considerable effects on the induced stress values. In addition, the interface permeability condition and soil characteristics play an important role in determining the dynamic response of the borehole. Finally,the obtained results are compared with the relevant analyses existing in the literature for some limit cases, and good agreement is achieved.

关键词：

Neuroinflammation as a therapeutic target in huntington's disease

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第3期20卷 817-818页

作者： Andrea Kwakowsky Thulani h.Palpagama Center for Brain Research and Department of Anatomy and Medical Imaging Faculty of Medical and Health SciencesUniversity of AucklandAucklandNew Zealand Pharmacology and Therapeutics School of MedicineGalway Neuroscience CentreUniversity of GalwayGalwayIreland

In 1872, George huntington presented his essay “On Chorea” to the Meigs and Mason Academy of Medicine and, in doing so, detailed a disease that would later bear his name. huntington's disease(hD) is a genetic, neurodegenerative disease that manifests as the loss of motor control,cognitive impairment,and mood and psychiatric changes in paents.

关键词： huntington inflammation Medicine

Glial response in the midcingulate cortex in huntington’s disease

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第1期20卷 207-208页

作者： Thulani h.Palpagama Andrea Kwakowsky Center for Brain Research and Department of Anatomy and Medical Imaging Faculty of Medical and Health SciencesUniversity of AucklandAucklandNew Zealand Pharmacology and Therapeutics School of MedicineGalway Neuroscience CenterUniversity of GalwayGalwayIreland

huntington’s disease(hD)is a genetic disease characterized by the progressive degeneration of the striatum and *** can present with a variety of symptoms that can broadly be classified into motor symptoms,inclusive of choreatic movements and rigidity,mood and psychiatric symptoms,such as depression and apathy,and cognitive symptoms,such as cognitive *** causal mutation underlying hD results from an expansion of a CAG repeat sequence on the IT15 gene,resulting in the formation and accumulation of a mutant huntingtin protein.

关键词： huntington degeneration cortex

Effects of ethanol on hepatic cellular replication and cell cycleprogression

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2007年第37期13卷 4955-4959页

作者： Dahn L clemens Department of Internal Medicine University of Nebraska Medical Center and Veterans Affairs Medical Center Omaha Nebraska 68105 United States

Ethanol is a hepatotoxin. It appears that the liver is the target of ethanol induced toxicity primarily because it is the major site of ethanol metabolism. Metabolism of ethanol results in a number of biochemical changes that are thought to mediate the toxicity associated with ethanol abuse. These include the production of acetaldehyde and reactive oxygen species, as well as an accumulation of nicotinamide adenine dinucleotide （NADh）. These biochemical changes are associated with the accumulation of fat and mitochondrial dysfunction in the liver. If these changes are severe enough they can themselves cause hepatotoxicity, or they can sensitize the liver to more severe damage by other hepatotoxins. Whether liver damage is the result of ethanol metabolism or some other hepatotoxin, recovery of the liver from damage requires replacement of cells that have been destroyed. It is now apparent that ethanol metabolism not only causes hepatotoxicity but also impairs the replication of normal hepatocytes. This impairment has been shown to occur at both the GI/S, and the G2/M transitions of the cell cycle. These impairments may be the result of activation of the checkpoint kinases, which can mediate cell cycle arrest at both of these transitions. Conversely, because ethanol metabolism results in a number of biochemical changes, there may be a number of mechanisms by which ethanol metabolism impairs cellular replication. It is the goal of this article to review the mechanisms by which ethanol metabolism mediates impairment of hepatic replication.

关键词： Cyclin-dependent kinases Cell cycle Liverregeneration Ethanol metabolism Acetaldehyde Alcoholic liver disease

Completeness of citizen science biodiversity data from a volunteered geographic information perspective

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geo-Spatial Information Science 2017年第1期20卷 3-13页

作者： clemens Jacobs Alexander Zipf GIScience Research Group Institute of GeographyHeidelberg UniversityHeidelbergGermany

Observations of living organisms by citizen scientists that are reported to online portals are a valuable source of *** are also a special kind of volunteered geographic information(VGI).VGI data have issues of completeness,which arise from biases caused by the opportunistic nature of the data collection *** examined the completeness of bird species represented in citizen science observation data from eBird and iNaturalist in US National Parks(NPs).We used approaches for completeness estimation which were developed for data from OpenStreetMap,a crowdsourced map of the ***,we used an extrinsic approach,comparing species lists from citizen science data with National Park Service ***,we examined two intrinsic approaches using total observation numbers in NPs and the development of the number of new species being added to the data-set over *** from the extrinsic approach provided appropriate completeness estimations to evaluate the intrinsic *** found that total observation numbers are a good estimator of species completeness of citizen science data from US *** is also a close relationship between species completeness and the ratio of new species added to observation data *** numbers in a given year.

关键词： Citizen science Volunteered Geographic Information(VGI) data quality completeness

Electrochemical Fabrication of rGO-embedded Ag-TiO2 Nanoring/Nanotube Arrays for Plasmonic Solar Water Splitting

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano-Micro Letters 2019年第4期11卷 674-689页

作者： Lixia Sang Lei Lei clemens Burda Key Laboratory of Enhanced heat Transfer and Energy Conservation Ministry of Education and Key Laboratory of Heat Transfer and Energy ConversionBeijing MunicipalityCollege of Environmental and Energy EngineeringBeijing University of TechnologyBeijing 100124People’s Republic of China Department of Chemistry Center for Chemical Dynamics and Nanomaterials ResearchCase Western Reserve University10900 Euclid AvenueClevelandOH 44106USA

Effective utilization of hot electrons generated from the decay of surface plasmon resonance in metal nanoparticles is conductive to improve solar water splitting ***,Ag nanoparticles and reduced graphene oxide(rGO)co-decorated hierarchical TiO2 nanoring/nanotube arrays(TiO2 R/T)were facilely fabricated by using two-step electrochemical anodization,electrodeposition,and photoreduction *** studies were conducted to elucidate the effects of rGO and Ag on the morphology,photoresponse,charge transfer,and photoelectric properties of ***,scanning electron microscope images confirm that the Ag nanoparticles adhered on TiO2 R/T and TiO2 R/T-rGO have similar diameter of 20 nm except for TiO2 R-rGO/***,the UV-Vis DRS and scatter spectra reveal that the optical property of the Ag-TiO2 R/T-rGO ternary composite is enhanced,ascribing to the visible light absorption of plasmonic Ag nanoparticles and the weakening effect of rGO on light ***,intensity-modulated photocurrent spectroscopy and photoluminescence spectra demonstrate that rGO can promote the hot electrons transfer from Ag nanoparticles to Ti substrate,reducing the photogenerated electron-hole ***,Ag-TiO2 R/T-rGO photoanode exhibits high photocurrent density(0.98 mA cm?2)and photovoltage(0.90 V),and the stable h2 evolution rate of 413μL h?1 cm?2 within 1.5 h under AM 1.5 which exceeds by 1.30 times than that of pristine TiO2 R/*** line with the above results,this work provides a reliable route synergizing rGO with plasmonic metal nanoparticles for photocatalysis,in which,rGO presents a broad absorption spectrum and effective photogenerated electrons transfer.

关键词： TiO2 nanoring/nanotube hierarchical structure Reduced graphene oxide Spectral responses Plasmonic Ag nanoparticles Water splitting

Measurements of Laminar Burning Velocities of Alternative Fuels:Application in Transport and Aerospace

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2023年第2期32卷 503-512页

作者： RIChTER Sandra BRAUN-UNKhOFF Marina NAUMANN clemens German Aerospace Center(DLR) Institute of Combustion TechnologyDepartment of Chemical Kinetics and AnalyticsStuttgart 70569Germany

The laminar burning velocity belongs to the fundamental combustion properties of fuels being a measure for their heat release,flame length,as well as reactivity and combustion stability,and thus,may impact the design of burners and combustion ***,these experimental data are needed for the validation and optimization within the construction and development of detailed chemical kinetic reaction *** this study,an overview of the different applications of fuel characterization regarding the specific area of interest(road transport,aviation,and aerospace)will be *** on the application,effects of different molecular characteristics on the laminar burning velocity are evaluated:the presence of oxygen atoms and the grade of branching in a specific fuel molecule as well as the difference in the type of a chemical bond,here,single and double *** of alternative fuels being discussed in the present study are:(Ⅰ)oxymethylene ether(OMEn)in the field of road transport;(Ⅱ)a paraffinic Alcohol-to-Jet fuel as sustainable aviation fuel;and(Ⅲ)mixtures of ethane or ethene with nitrous oxide as green propellants for rocket propulsion applications.

关键词： laminar burning velocity alternative sustainable fuels road transport aviation fuels green propellants