检索结果-南通市图书馆

Mobile NMR for geophysical analysis and materials testing

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2009年第1期6卷 1-7页

作者： BLüMICH bernhard MAULER Jrg HABER Agnes PERLO Juan DANIELI Ernesto CASANOVA Federico Institut für Technische und Makromolekulare Chemie RWTH Aachen University

Initiated by well logging NMR, portable NMR instruments are being developed for a variety of novel applications in materials testing, process analysis and control, which provides new opportunities for geophysical investigations. Small-diameter cylindrical sensors can probe short distances into the walls of slim-line logging holes, and single-sided sensors enable non-destructive testing of large objects. Both sensors are characterized by small sensitive volumes. Barrel-shaped magnets that accommodate the sample in their center have higher sensitivity due to a larger sensitive volume but can accommodate only samples like drill cores, which fit in size to the diameter of the magnet bore. Both types of magnets can be scaled down to the size of a coffee mug to arrive at sub-compact NMR equipment. Portable NMR magnets are reviewed in the context of applications related to geophysics.

关键词： Mobile NMR portable NMR relaxation imaging spectroscopy

Comment on 'Will Earth's next supercontinent assemble through the closure of the Pacific Ocean?'

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

National Science Review 2022年第12期9卷 70-70页

作者： bernhard Steinberger Centre for Earth Evolution and Dynamics University of Oslo GFZ German Research Centre for Geosciences

In their paper,Huang et *** that both introversion and extroversion can occur within the same model,if parameters are *** by itself is an important result,however,the authors go further to conclude which continents assembled with introversion and which ones with *** conclusion rests on the assumption that a thicker crust leads to a stronger lithosphere,

关键词：

A dominant insulin-specific and islet-destructive T-cell response is sufficient to activate CD8 T cells directed against the fatty-acid receptor GPR40

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Cellular & Molecular Immunology 2020年第6期17卷 659-661页

作者： Andreas Spyrantis Jana Krieger Katja Stifter bernhard Otto Boehm Reinhold Schirmbeck Department of Internal Medicine I Ulm University Hospital/Albert Einstein Allee 2389081 UlmGermany Lee Kong Chian School of Medicine Nanyang Technological UniversitySingaporeSingapore Imperial College London LondonUK

Type 1 diabetes mellitus(T1D)is an autoimmune disease that is characterized by a progressive infiltration of autoreactive T cells into the pancreatic islets and the destruction of insulin-producing beta cells.1 It is generally assumed that T1D is initiated by yet unidentified T cells that escape from thymic negative selection2 and trigger an initial destruction of beta cells.3 These initial hits could generate suitable conditions in beta cells and/or in islets that favor the coactivation and amplification of autoreactive T cells directed against a broad spectrum of beta cell-specific antigens,such as GAD65,IGRP,and IA-2.

关键词： GPR40 islet directed

Positive effects of tree species richness on fine-root production in a subtropical forest in SE-China

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Plant Ecology 2017年第1期10卷 146-157页

作者： Zhenkai Sun Xiaojuan Liu bernhard Schmid Helge Bruelheide Wensheng Bu Keping Ma State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of Sciences20 NanxincunXiangshanBeijing 100093China College of Life Sciences University of Chinese Academy of SciencesNo.19 Yuquan RoadShijingshan DistrictBeijing 100049China Department of Evolutionary Biology and Environmental Studies University of ZürichWinterthurerstr.1908057 ZürichSwitzerland Institute of Biology/Geobotany and Botanical Garden Martin Luther University Halle WittenbergAm Kirchtor 106120 HalleGermany German Centre for Integrative Biodiversity Research(iDiv)Halle-Jena-Leipzig Deutscher Platz 5e04103 LeipzigGermany

Aims Fine roots play an important role in the biogeochemical cycles of terrestrial ecosystems and are vital for understanding forest ecosystem functioning and *** plant species diversity has been largely reported to increase aboveground community biomass,but how biodiversity affects fine-root production and the related mechanisms in forests remain *** this study,we aim to answer two questions:(i)does fine-root production increase with tree species richness?(ii)Can this effect be explained by niche complementarity among species?Methods We analyzed data from a large forest biodiversity experiment(BEF-China)with 5-year-old ***-root growth was measured as standing biomass and annual fine-root regrowth was estimated using ingrowth ***,relative yield was calculated to test whether over-or under-yielding occurred when mixtures were compared with the average monoculture of the species included in the *** calculated functional diversity for fine-root(≤2 mm in diameter)traits by Rao’s quadratic entropy index for each species *** effects of manipulated tree species richness and identity on fine-root traits were analyzed with linear mixed-effects *** models were also used to test the relationships between tree species richness and fine-root standing biomass,annual regrowth and vertical *** Findings Fine roots of more than one species were found in half of the soil cores in mixtures indicating that belowground interactions in these young forest stands occurred much earlier than canopy *** found significant differences among species in fine-root traits such as diameter and specific root length(SRL),which suggested different resource-use strategies and niche partitioning among *** fine-root diameter of species ranged from 0.31 to 0.74 mm,mean SRL ranged from 12.43 m·g^(−1)to 70.22 m·g^(−1)and mean vertical distribution indexβranged from 0.68 to *** was a significant positive re

关键词： Biodiversity fine-root biomass fine-root regrowth niche complementarity over-yielding

Does a giant tortoise taxon substitute enhance seed germination of exotic fleshy-fruited plants?

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Plant Ecology 2013年第1期6卷 57-63页

作者： Annika Waibel Christine J.Griffiths Nicolas Zuel bernhard Schmid Matthias Albrecht Institute of Evolutionary Biology and Environmental Studies University of ZurichWinterthurerstrasse 1908057 ZurichSwitzerland Mauritian Wildlife Foundation Grannum RoadVacoasMauritius School of Biological Sciences University of BristolWoodland RoadBristol BS81UGUK Present address:Mediterranean Institute for Advanced Studies Department of Biodiversity and Conservation (‘Consejo Superior de Investigaciones Cientı´ficas-Universitat de les Illes Balears’)Miquel Marques 2107190 EsporlesMallorcaBalearic IslandsSpain

Aims The use of exotic species as taxon substitutes to restore lost ecological interactions is currently hotly *** gigantea giant tortoises have recently been introduced to three islands in the Mascarene archipelago(Ile aux Aigrettes,Round Island and Rodrigues)to resurrect herbivory and seed dispersal functions once performed by extinct giant ***,potential unintended impacts by frugivore substitutes on native ecosystems,*** they will facilitate the germination of exotic plant species,are largely *** investigated whether *** introduced to Rodrigues in 2006 could enhance the germination percentage of four widespread fleshy-fruited exotic species on the *** germination trials to forecast unintended impacts that could arise from the introduction of a frugivorous taxon substitute enables conservation managers to limit potential adverse negative interactions before they *** In germination trials that ran over 4 months,we investigated the effects of ingestion(gut passage and deposition in faeces)by subadult and adult *** on the germination percentage of four exotic fleshy-fruited plant species introduced to *** fed fruits of these plant species to sub-adult and adult *** to test how variation in age and size of the frugivore would affect seed *** of distinctly coloured plastic pellets together with the fruits allowed us to test for individual tortoise effects on seed *** Findings Ingestion by *** increased the percentage of seeds germinating of Mimusops coriacea and Lantana camara,but not percentage of germination of Veitchia merrillii or Wikstroemia *** were more likely to germinate following ingestion by sub-adult rather than adult tortoises,which may be a consequence of the shorter gut passage time observed for *** results demonstrate that introduced frugivorous taxon substitutes could facilitate germination of exot

关键词： ecological analogues exotic species invasion gut passage plant–frugivore interactions seed germination

Selection in monoculture vs. mixture alters plant metabolic fingerprints

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Plant Ecology 2015年第5期8卷 549-557页

作者： Debra Zuppinger-Dingley Dan F.B.Flynn Helmut Brandl bernhard Schmid Institute of Evolutionary Biology and Environmental Studies University of ZurichWinterthurerstrasse 190CH-8057 ZurichSwitzerland The Arnold Arboretum of Harvard University 1300 Centre StreetBostonMA 02131USA

Aims In grassland biodiversity experiments,positive biodiversity effects on primary productivity increase over *** research has shown that differential selection in monoculture and mixed-species communities leads to the rapid emergence of monoculture and mix-ture types,adapted to their own biotic *** used eight plant species selected for 8 years in such a biodiversity experiment to test if monoculture and mixture types differed in metabolic pro-files using infrared *** Fourier transform infrared spectroscopy(FTIr)was used to assess metabolic fingerprints of leaf samples of 10 individuals of each species from either monocultures or *** FTIr spectra were analyzed using multivariate procedures to assess(i)whether indi-viduals within species could be correctly assigned to monoculture or mixture history based on the spectra alone and(ii)which parts of the spectra drive the group assignment,*** metabolic groups were subject to differential selection in monocultures *** Findings Plant individuals within each of the eight species could be classified as either from monoculture or mixture selection history based on their FTIr *** metabolic groups were differentially selected in the different species;some of them may be related to defense of patho-gens accumulating more strongly in monocultures than in *** rapid selection of the monoculture and mixture types within the eight study species could have been due to a sorting-out process based on large initial genetic or epigenetic variation within the species.

关键词： biodiversity plant evolution selection FTIr spectroscopy metabolic fingerprint

Diverse plant mixtures sustain a greater arbuscular mycorrhizal fungi spore viability than monocultures after 12 years

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Plant Ecology 2020年第4期13卷 478-488页

作者： Peter Dietrich Christiane Roscher Adam Thomas Clark Nico Eisenhauer bernhard Schmid Cameron Wagg Institute of Ecology and Evolution Friedrich-Schiller-University JenaDornburger Strasse 15907743 JenaGermany Department of Evolutionary Biology and Environmental Studies University of ZurichWinterthurerstrasse 1908057 ZurichSwitzerland Department of Physiological Diversity UFZHelmholtz Centre for Environmental ResearchPermoserstrasse 1504318 LeipzigGermany German Centre of Integrative Biodiversity Research(iDiv)Halle-Jena-Leipzig Deutscher Platz 5e04103 LeipzigGermany Institute of Biology Leipzig UniversityDeutscher Platz 5e04103 LeipzigGermany Department of Geography University of ZurichWinterthurerstrasse 1908057 ZurichSwitzerland Fredericton Research and Development Center Agriculture and Agri-Food Canada850 Lincoln RoadFrederictonNew Brunswick E3B 1P9Canada

Aims Intensive land management practices can compromise soil biodiversity,thus jeopardizing long-term soil *** mycorrhizal fungi(AMF)play a pivotal role in promoting soil productivity through obligate symbiotic associations with ***,it is not clear how properties of plant communities,especially species richness and composition influence the viability of AMF populations in *** Here we test whether monocultures of eight plant species from different plant functional groups,or a diverse mixture of plant species,maintain more viable AMF *** address this question,we extracted AMF spores from 12-year old plant monocultures and mixtures and paired single AMF spores with single plants in a factorial design crossing AMF spore origin with plant species *** Findings AMF spores from diverse plant mixtures were more successful at colonizing multiple plant species and plant individuals than AMF spores from plant ***,we found evidence that AMF spores originating from diverse mixtures more strongly increased biomass than AMF from monocultures in the legume Trifolium repens *** viability and ability to interact with many plant species were greater when AMF spores originated from 12-year old mixtures than *** results show for the first time that diverse plant communities can sustain AMF viability in soils and demonstrate the potential of diverse plant communities to maintain viable AMF propagules that are a key component to soil health and productivity.

关键词： aboveground–belowground interactions biodiversity biomass production mutualism plant–AMF interaction root colonization

Calculation of skid resistance from texture measurements

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Traffic and Transportation Engineering(English Edition) 2015年第1期2卷 3-16页

作者： Andreas Ueckermann Dawei Wang Markus Oeser bernhard Steinauer Institute of Highway Engineering RWTH Aachen University

There is a wide range of routine skid resistance measurement devices on the market. All of them are measuring the friction force between a rubber wheel and the wetted road surface. Common to all of them is that they are relatively complex and costly because generally a truck carrying a large water tank is needed to wet the surface with a defined water layer. Because of the limited amount of water they can carry they are limited in range. Besides that the measurement is depending on factors like water film thickness, temperature, measurement speed, rubber aging, rubber wear and even road evenness and curviness. All of these factors will affect the skid resistance and are difficult to control. We present a concept of contactless skid resistance measurement which is based on optical texture measurement and consists of two components： measurement of the pavement texture by means of an optical measufin~ system and calculation of the skid resistance based on the measured texture by means of a rubber friction model. The basic assumptions underlying the theoretical approach and the model itself based on the theory of Persson are presented. The concept is applied to a laboratory device called Wehner/Schulze （W/S） machine to prove the theoretical approach. The results are very promising. A strong indication could be provided that skid resistance could be measured without contact in the future.

关键词： Skid resistance Contactless measurement Pavenent texture Rubber friction model

Detection of bladder trabeculation by voiding cystourethrography and sonography:observations in boys with posterior urethral valves

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

World Journal of Pediatric Surgery 2021年第3期4卷 16-20页

作者： Jonas Thüminger bernhard Haid Josef Oswald Kinder-und Jugendchirurgie Landeskrankenhaus Salzburg-Universitatsklinikum der Paracelsus Medizinischen PrivatuniversitatSalzburgAustria Pediatric Urology Ordensklinikum Linz Barmherzige Schwestern HospitalLinzAustria

Background As trabeculated bladder wall is often referred to as a sign of chronically increased intravesical pressure,we investigated whether voiding cystourethrography(VCUG)or sonography reliably predicts bladder trabeculation on later *** A total of 76 consecutive patients(2012-2017)with cystoscopically confirmed posterior urethral valves(PUV)and pre-endoscopy VCUG were *** data were available for 68 of these *** findings were reassessed and compared with endoscopic findings using Fisher’s exact test and Spearman’s rank *** VCUG showed a sensitivity of 83.3%and a specificity of 30%in predicting trabeculation on a later urethrocystoscopy,with no significant difference in determining mild or severe forms(p=0.51).Sonography proved a sensitivity of 27.6%and a specificity of 70%,with no correlation between sonographic signs and trabeculation on cystoscopy(r=0.1311).In addition,vesicoureteral reflux had no significant influence as a possible pressure pop-off mechanism on the development of trabeculation in our *** While VCUG predicts bladder trabeculation in children with PUV with limited reliability,sonography mostly fails to detect ***,such findings should only be used with utmost caution in relation to clinical decision-making.

关键词： bladder sonography specificity