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A SURVEY OF WORKS ON ThE ThEORY OF TOROIDAL ShELLS AND CURVED TUBES

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Acta Mechanica Sinica 1999年第3期15卷 225-234页

作者：任文敏刘文国张维 h.g.Reimerdes h.Oery Dept.of Engineering Mechanics Tsinghua UniversityBeijing 100084China Institute of Lightstructure RWTH AachenD-52062 AachenGermany

This paper gives a survey of works on the theory of toroidal shells which were done by our two universities in recent years.

关键词： toroidal shells curved tubes

MOF-derived ZrO_(2)/C-polyvinylidene fluoride composite towards negative permittivity regulation mechanism

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Journal of Materials Science & Technology 2024年第12期179卷 50-56页

作者： X.T.Song g.h.Fan Y.Liu R.h.Fan Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials(Ministry of Education) Jinan 250061China Institute of Advanced Electrical Materials Qingdao University of Science&TechnologyQingdao 266042China College of Ocean Science and Engineering Shanghai Maritime UniversityShanghai 201306China

Composites featuring negative permittivity have garnered significant attention for their potential in novel capacitance designs,coil-less electrical inductors,and electromagnetic shielding *** this study,we prepared polyvinylidene fluoride(PVDF)matrix composites filled with ZrO_(2)/C nanoparticles de-rived from metal-organic frameworks(MOFs)via a hot-pressing *** an increase in the ZrO_(2)/C content to 30 wt.%,electrical percolation was observed,accompanied by a transition mechanism from hopping conduction to metal-like *** enabled the realization of ZrO_(2)/C/PVDF composites with tailorable negative permittivity properties,attributed to the plasmonic oscillation of free electrons in the composites beyond the percolation threshold(30 wt.%).Furthermore,the permittivity transition along to a shift in the electrical behavior of the percolative composites from capacitive to *** explored the regulatory mechanism behind the negative permittivity in this random composite system,and our findings highlight the potential of these tunable negative permittivity media as promising candi-dates for diverse electromagnetic applications.

关键词： Negative permittivity Electrical properties Plasma oscillation Polymeric composites

Magnetic Properties of Ni Nanoparticles and Ni(C) Nanocapsules

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Journal of Materials Science & Technology 2002年第2期18卷 99-100页

作者： Z.J.Li g.h.Wen 等 ShenyangNationalLaboratoryforMaterialsScienceandInternationalCentreforMaterialsPhysics InstituteofMetalResearchChineseAcademyofSciencesShenyang110016China DepartmentofPhysics H

Structure and magnetic properties of Ni nanoparticles and Ni(C) nanocapsules were studied. The carbon atoms hardly affect the lattice of Ni to form Ni-C solid solution or nickel carbides. The large thermal irreversibility in zero-field-cooled and zero-field magnetization curves indicates magnetic blocking with a wide energy barrier. Saturation magnetization, remanent magnetization and coercivity of Ni(C) nanocapsules decrease with increasing temperature.

关键词： Nanoparticles Nanocapsules Magnetic properties

Λb^0-baryon production in pp collisions in the general-mass variable-flavour-number scheme,and comparison with CMS and LhCb data

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Chinese Physics C 2018年第8期42卷 34-44页

作者： g.Kramer h.Spiesberger II.Institut für Theoretische Physik Universitat HamburgLuruper Chaussee 149D-22761 HamburgGermany Institut für Physik Johannes-Gutenberg-UniversitatStaudinger Weg 7D-55099 MainzGermany Centre for Theoretical and Mathematical Physics and Department of Physics University of Cape TownRondebosch 7700South Africa

We calculate the next-to-leading-order cross section for the inclusive production ofΛ（b ）baryons in pp collisions in the general-mass variable-flavor-number *** use realistic evolved non-perturbative fragmentation functions obtained from fits to B-meson production in e^＋e^-annihilation and compare our results for transversemomentum and rapidity distributions with recent experimental data from the CMS and the LhCb collaborations at the CERN *** find satisfactory agreement in general,with some indication for the need to modify the available fragmentation functions at larger values of the scale variable.

关键词： heavy flavor production perturbative QCD Ab production

DEVELOPMENT OF NEW ThERMO-MEChANICAL SIMULATOR

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Acta Metallurgica Sinica(English Letters) 2004年第1期17卷 33-37页

作者： Z.g.Luo h.L.Su D.h.Zhang g.D.Wang X.h.Liu The State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 ChinaThe State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 ChinaThe State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 ChinaThe State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 ChinaThe State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 China

A new multifunction thermo-mechanical simulator was successfully developed. The accuracy of measurement and control is very high through all digital control. More than twenty tests may be fulfilled including tension, compression, torsion, combination large deformation that meets the study of supersteel, etc. Its performance is introduced in the paper, such as designed ideas, machine structure, man-machine interface, control system, etc.

关键词： thermo-mechanical simulator multifunction control system combination large deformation

Role of conspecifics and personal experience on behavioral avoidance of contaminated flowers by bumblebees

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Current Zoology 2019年第4期65卷 447-455页

作者： Bertrand Fouks Emily g. Robb h. Michael g. Lattorff lnstitut fur Biologie Molekulare Okologie Martin-Luther-Universitat Halle-Wittenberg Hoher Weg Halle (Saale) Germany Centre for Ecological and Evolutionary Synthesis (CEES) Department of Biosciences University of Oslo Oslo Norway Microbes and Pathogens Biology The Institute for Global Food Security School of Biological Sciences Queen's University Belfast United Kingdom lnternational Centre of Insect Physiology and Ecology (ICIPE) Nairobi Kenya german Centre for Integrative Biodiversity Research (iDiv) halle-Jena-Leipzig Deutscher Platz Leipzig Germany

Pollinators use multiple cues whilst foraging in eluding direct cues from flowers and in direct cues from other pollinators. The use of indirect social cues is common in social in sects, such as honeybees and bumblebees, where a social environment facilitates the ability to use such cues. Bumblebees use cues to forage on flowers according to previous foraging experiences. Flowers are an essential food source for pollinators but also pose a high risk of parasite infection through the shared use of flowers leading to parasite spillover. Nevertheless, bumblebees have evolved behavioral defense mechanisms to limit parasite infection by avoiding contaminated flowers. Mechanisms underlying the avoidance of contaminated flowers by bumblebees are poorly understood. Bumblebees were recorded having the choice to forage on non-contaminated flowers and flowers contaminated by a trypan osome gut parasite, Crithidia bombi. The use of different treatments with presence or absence of con specifics on both con taminated and non-contami nated flowers allowed to investigate the role of social visual cues on their pathogen avoidance behavior. Bumblebees are expected to use social visual cues to avoid contaminated flowers. Our study reveals that the presence of a con specific on flowers either con taminated or not does not help bumblebee foragers avoiding contaminated flowers. Nevertheless, bumblebees whereas gaining experie nee tend to avoid their con specific when placed on contami nated flower and copy it whe n on the non-contami nated flower. Our experime nt suggests a detrime ntal impact of floral see nt on disease avoidanee behavior.

关键词： host-parasite in teractions social learning pollinators inadvertent social information behavioral immunity copying behavior

Successional trends and processes on a glacial foreland in Southern Iceland studied by repeated species counts

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Ecological Processes 2019年第1期8卷 138-148页

作者： Taylor g.glausen Lawrence h.Tanner Jacobs School of Medicine and Biomedical Sciences State University of New York at BuffaloBuffaloNY 14203USA Department of Biological and Environmental Sciences Le Moyne CollegeSyracuseNY 13214USA

Introduction:Primary succession on glacial forelands is increasingly relevant as rapid glacial retreat is exposing growing land areas to plant *** investigated temporal trends,controls,and outcomes in floral succession on a subarctic glacial ***,we examined changes in community composition(mosses,low shrubs,forbs,trees,and graminoids)over long-term(decadal)and short-term(he underlying processes responsible for the observed successional ***:The study area was the foreland of the Skaftafellsjӧkull,located in Vatnajӧkull National Park near the south coast of *** established nine transect lines at varying distances from the ice front representing surfaces of age ranging from less than one decade to over 100 *** transect consisted of five measurement stations of 1 m2 where we measured vegetative cover(VC),species richness(SR),and species density(SD)and calculated species evenness(SE).Measurements were made initially in 2007 and repeated at the same geographic coordinates in ***:VC increased with distance from the ice front from 16%to over 90%.SR and SD increased from the youngest pioneer community through a mid-successional stage corresponding to an age of over 60 but less than 100 *** VC but declining SR,SD,and SE characterized the oldest(over 100 years)bryophyte-dominated *** turnover,which involved forbs almost exclusively,increased moderately from early through midsuccessional sites and declined on older *** of the measurements made in 2014 to those made in 2007 demonstrates increased SR at mid-successional sites while SD remained relatively ***:At a small scale,colonization is controlled by local factors such as microtopography and aspect,particularly in proximity to the *** the landscape level,changes in VC and community structure are controlled by time and nutrient *** nutrient level

关键词： Primary succession glacial foreland Species richness Species density Bryophyte

Paleosols of the upper Paleozoic Sangre de Cristo Formation,north-central New Mexico:Record of early Permian palaeoclimate in tropical Pangaea

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Journal of Palaeogeography 2017年第2期6卷 144-161页

作者： Lawrence h. Tanner Spencer g. Lucas Department of Biological Sciences Le Moyne CollegeSyracuseNY 13214USA New Mexico Museum of Natural history 1801 Mountain Road N.W.AlbuquerqueNM 87014USA

The lower Permian(Wolfcampian) Sangre de Cristo Formation of northern New Mexico consists of silty mudstones and laterally discontinuous sandstones deposited on an aggrading alluvial ***,mudstones display a variety of pedogenic *** mudstone fabrics vary from platy to prismatic;some beds display prominent pedogenic ***-colored root traces are common throughout the section,as are calcareous nodules,which vary from small bodies with diffuse boundaries to vertically stacked,discrete,cm-scale nodules(rhizocretions),and less commonly form coalescing *** occur only in the lower portion of the ca.90-m measured *** of the mudstone beds contain calcretes that are immature(calcic Protosols to calcic Argillisols),but the lower to middle portion of the section also contains mature calcrete horizons(argillic Calcisols and Calcisols).Intercalated micritic limestone beds with sharp contacts containing root traces,are of laterally variable thickness and grade to nodular *** are interpreted as floodplain pond carbonates that have undergone pedogenic alteration(palustrine limestones),indicating long periods of exposure under strongly seasonal climatic *** isotopic composition of the pedogenic carbonate displays a substantial range of values,but most of the range of variation in isotopic composition is accounted for by isotopically heavier carbonate(both carbon and oxygen) precipitated in shallow ponds subject to intense pedogenic reworking(palustrine carbonate).During the early Permian,northern New Mexico was situated in a near equatorial position(ca.4° N).The overall character of the paleosols suggests a persistent warm,semi-humid,seasonal climate throughout most of the interval of deposition during the Wolfcampian,but with episodically increased aridity during formation of the more mature *** long-term trend of climate change is evident in the stratigraphic section examined for this study.

关键词： Sangre de Cristo Formation Wolfcampian Vertisol Argillisol Calcisol Protosol

Effect of Soil Water Repellency on Energy Partitioning Between Soil and Atmosphere:A Conceptual Approach

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Pedosphere 2014年第4期24卷 498-507页

作者： h.SChONSKY A.PETERS g.WESSOLEK Department of Soil Conservation Institute of EcologyTechnical University of BerlinD-10587 Berlin(Germany)

Water repellency(WR) is a phenomenon known from many soils around the world and can occur in arid as well as in humid climates;few studies,however,have examined the effect of soil WR on the soil-plant-atmosphere energy *** aim of our study was to estimate the effects of soil WR on the calculated soil-atmosphere energy balance,using a solely model-based *** made out evapotranspiration to have the largest influence on the energy balance;therefore the effect of WR on actual evapotranspiration was *** achieve this we used climate data and measured soil hydraulic properties of a potentially water-repellent sandy soil from a site near Berlin,germany.A numerical 1D soil water balance model in which WR was incorporated in a straightforward way was applied,using the effective cross section *** were carried out with vegetated soil and bare *** simulation results showed a reduction in evapotranspiration of 30-300 mm year^(-1)(9%-76%) at different degrees of WR compared to completely wettable soil,depending on the severity degree of soil *** energy that is not being transported away by water vapor(i.e.,due to reduced evapotranspiration) had to be transformed into other parts of the energy balance and thus would influence the local climate.

关键词： climate effective cross section evapotranspiration soil-atmosphere energy balance soil hydraulic property water balance