检索结果-南通市图书馆

Experimental and Statistical Analysis of Fatigue Behavior in Zr-based Bulk Metallic Glass

在线全文

学校读者我要写书评

暂无评论

稀有金属材料与工程 2024年第11期53卷 3010-3016页

作者： Yao Zhifeng Qiao Jichao Pelletier jean-Marc Yao Yao School of Civil Engineering Xi'an University of Architecture&TechnologyXi'an 710055China Dongguan Sanhang Innovation Institute Dongguan 523808China School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi'an 710072China Institut National des Sciences Appliquées de Lyon Universitéde LyonLyon F-69621France School of Materials and Chemical Engineering Xi'an Technological UniversityXi'an710021China

Three-point bending fatigue experiments were conducted on a typical Zr-based bulk metallic glass(BMG)at ambient temperature to investigate the fatigue behavior under cyclic loading *** show that the stress amplitude-cycles to failure(S-N)curve of the Zr-based BMG is determined,and the fatigue endurance limit is 442 MPa(stress amplitude).To evaluate the probability-stress amplitude-cycles to failure(P-S-N)curve,an estimation method based on maximum likelihood was proposed,which relies on statistical principles to estimate the fatigue life of the material and allows for a reduction in the number of samples required,offering a cost-effective and efficient alternative to traditional testing *** experimental results align with the American Society for Testing and Materials(ASTM)standard,indicating the reliability and accuracy of this estimation method in evaluating the fatigue behavior of Zr-based BMG.

关键词： bulk metallic glass P-S-N curve fatigue test statistical analysis

A new non-specificity measure in evidence theory based on belief intervals

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2016年第3期29卷 704-713页

作者： Yang Yi Han Deqian jean Dezert SKLSVMS School of AerospaceXi'an Jiaotong UniversityXi'an 710049China Center for Information Engineering Science Research Xi'an Jiaotong UniversityXi'an 710049China ONERA The Freneh Aerospace LabChemin de la HunireF-91761 PalaiseauFrance

In the theory of belief functions, the measure of uncertainty is an important concept, which is used for representing some types of uncertainty incorporated in bodies of evidence such as the discord and the non-specificity. For the non-specificity part, some traditional measures use for reference the Hartley measure in classical set theory; other traditional measures use the simple and heuristic function for joint use of mass assignments and the cardinality of focal elements. In this paper, a new non-specificity measure is proposed using lengths of belief intervals, which represent the degree of imprecision. Therefore, it has more intuitive physical meaning. It can be proved that our new measure can be rewritten in a general form for the non-specificity. Our new measure is also proved to be a strict non-specificity measure with some desired properties. Numerical examples, simulations, the related analyses and proofs are provided to show the characteristics and good properties of the new non-specificity definition. An example of an application of the new non- specificity measure is also presented.

关键词： Belief interval Evidence theoryImprecision Non-specificity Uncertainty

Basic belief assignment approximations using degree of non-redundancy for focal element

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2019年第11期32卷 2503-2515页

作者： Yi YANG Deqiang HAN jean DEZERT SKLSVMS School of AerospaceXi'an Jiaotong UniversityXi'an 710049China Center for Information Engineering Science Research XVan Jiaotong UniversityXi'an 710049China ONERA The French Aerospace LabChemin de la HunierePalaiseau F-91761France

Dempster-Shafer evidence theory, also called the theory of belief function, is widely used for uncertainty modeling and reasoning. However, when the size and number of focal elements are large, the evidence combination will bring a high computational complexity. To address this issue,various methods have been proposed including the implementation of more efficient combination rules and the simplifications or approximations of Basic Belief Assignments(BBAs). In this paper,a novel principle for approximating a BBA into a simpler one is proposed, which is based on the degree of non-redundancy for focal elements. More non-redundant focal elements are kept in the approximation while more redundant focal elements in the original BBA are removed first. Three types of degree of non-redundancy are defined based on three different definitions of focal element distance, respectively. Two different implementations of this principle for BBA approximations are proposed including a batch and an iterative type. Examples, experiments, comparisons and related analyses are provided to validate proposed approximation approaches.

关键词： BBA approximation Belief functions Evidence theory Focal element Non-redundancy

Effects of indole-3-butyric acid and age of stem cuttings on root morphology,growth,and survival of Cornus sericea

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2023年第2期34卷 433-440页

作者： Sahari Inoue Chibuzo Ilogu jean-Marie Sobze Northern Alberta Institute of Technology Centre for Boreal ResearchPeace RiverAB T8S 1R2Canada Fine Phenotyping Lab Crop Health and ProtectionHarpenden AL52JQUK

Red osier dogwood(Cornus sericea L.),widely distributed throughout North America,is essential for wildlife,thus *** is recommended for reclamation or revegetation of sites disturbed by oil and gas extraction because it tolerates a wide range of soil types and high pH *** germination of this species is extremely difficult with long stratification requirements and poor germination,cuttings facilitate *** this study,to develop techniques to propagate the species from stem cuttings,four concentrations of indole-3-butyric acid(IBA)and two cutting ages previous year’s growth(PYG)and current year’s growth(CYG)were investigated for survival and *** 4 months,survival rate,height growth,and shoot biomass from PYG cuttings were enhanced with IB *** contrast,IB A did not affect these parameters in CYG *** morphology was significantly affected by IB A concentration and cutting ***,at higher concentrations,increased root surface and *** root surface area and length of PYG cuttings were increased,which may facilitate the absorption of essential resources and consequently increase *** results indicate that increasing the concentration of IB A may be an effective way to have better plant survival and growth of previous year’s cuttings in red osier dogwood.

关键词： Vegetative propagation IBA Chronological age Cornus sericea L. Survival rate

Wear Behavior of a Bio-inspired Bearing for off-center Loads

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2020年第6期17卷 1251-1262页

作者： Delphine Sysaykeo jean-Marc Linares Emmanuel Mermoz Alix-Marseile Universite CNRSCentre National de la Recherche ScientifiqueISMInstitut des Sciences du MouvementMarseille 13009France Advanced concepts and Dynamic systems architecture department Airbus HelicoptersAeroport International Marseille ProvenceMarignane 13700France

Misalignment is one of the most common causes of wear in bush *** improvements have been proposed by many ***,it did not efficiently reduce the *** geometrical designs sometimes reach their *** this reason,a bio-inspired design is proposed to solve the *** this article,a bio-inspired bearing suited to misalignment was tested and compared to a classical bush *** contact pressures of both bearings were compared with static Finite Element(FE)simulations for off-center *** to the complex shape of the involved contact,the performances of both bearings were also studied over *** wear behaviors were predicted with a numerical *** methodologies emplaced to simulate the wear were described in this ***,the wear coefficient determination obtained by experimental testing was *** pressure value,the contact zone and the wear depth were compared and *** wear results for the classical bearing are in accordance with the *** simulations show a deeper wear on the classical bush bearing than on the bio-inspired *** leads to a longer period of service life for the bio-inspired bearing.

关键词： biologically inspired design bush bearing wear simulation

Retinoid receptor-related orphan receptor alpha： a key gene setting brain circuits

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2018年第5期13卷 791-794页

作者： Tania Vitalis jean Mariani PROTECT Institut National de la Santé et de la Recherche Médicale Université Paris Diderot Paris France Université Pierre et Marie Curie Sorbonne Université Paris France Centre National de la Recherche Scientifique Unité Mixte de Recherche 8256 Institut de Biologie de Paris Seine (IBPS) Biological adaptation and ageing (B2A) Team Brain Development Repair and Ageing Paris France Assistance Publique - Hopitaux de Paris Départements Hospitalo-Universitaires FAST Institut de la Longévité Ivry-Sur-Seine France

The retinoid receptor-related orphan receptor alpha（RORα） is thought to act as a constitutive activator of transcription by binding to the ROR response element（RORE） of target genes. Several mouse models in which RORα is defective have revealed the decisive roles of RORα on the development, maturation and neuroprotection of various cerebral regions including the cerebellar and somatosensory systems. We have recently shown that RORα is needed for accurate thalamic sensory system organization and somatosensory cortex development. The phenotype of various RORα deficient mice models（staggerer mutant or mouse lacking RORα in specific somatosensory regions） is, in part, reminiscent of what has been described in mice lacking thyroid hormone triiodothyronine（T3）. As in in vitro studies or in other models, our studies strongly suggest that the T3/RORα-pathway, among others, is in part responsible for the staggerer phenotype. We have indeed identified some genes that were both regulated by T3 and RORα and that are known to be implicated in the cerebellar or somatosensory system development. Moreover, several groups have shown that RORα is at the crossroad of many biological processes and pathologies, including psychiatric and degenerative disorders. In particular, defective RORα-signalling has been demonstrated in humans to be associated with the emergence of autistic-like disorders. We believe that determining the appropriate amount of RORα activity could be crucial in detecting and preventing the emergence of specific brain diseases.

关键词： cerebellum cerebral cortex development maturation neuroprotection psychiatric disorders somatosensory system

Soil Macrofaunal Communities are Heterogeneous in Heathlands with Different Grazing Intensity

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2015年第4期25卷 524-533页

作者： jean-Franois PONGE Sandrine SALMON Amélie BENOIST jean-Jacques GEOFFROY Muséum National d’Histoire Naturelle CNRS UMR 7179 4 avenue du Petit Chteau 91800 Brunoy (France) Muséum National d’Histoire Naturelle CNRS UMR 7204 4 avenue du Petit Chteau 91800 Brunoy (France)

Moderate grazing by cattle increases the heterogeneity of soil and vegetation. This has been suggested as an ecologically sustainable mean of managing natural environments endangered by tree encroachment, such as heathlands. Our study was performed to test the impact of grazing intensity on soil macroinvertebrate communities in heterogeneous landscapes in a private property eligible to the Natura 2000 European Network of Special Protection Areas within the Brenne Natural Regional Park （Indre, ~rance）. We sampled macroinvertebrates along a broken line crossing 5 different land-use types, from pasture to pine forest, passing through a besom heath （Erica scoparia） heathland at 3 levels of cattle pressure. We hypothesized that： i） litter-dwelling （mostly arthropods and mollusks） and soil-dwelling macroinvertebrates （mostly earthworms） would respond in an opposite manner to various grazing intensities, and ii） intermediate cattle pressure （pastured heath） would increase soil and community heterogeneity. The results supported the first hypothesis, which was explained by land-use impacts mediated by soil properties. However, our results supported only partly the second hypothesis since maximum dissimilarity （whether in the composition of soil macroinvertebrate communities or in soil features） was observed in only one out of the two pastured heaths where cattle pressure was intermediate.

关键词： besom heath cattle grazing heterogeneity land-use types soil macroinvertebrates

Water Losses in Arid and Semi-Arid Zone:Evaporation, Evapotranspiration and Seepage

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2012年第2期9卷 256-261页

作者： MUPENZI jean de la Paix LI Lanhai GE Jiwen NGAMIJE jean ACHAL Verenyam HABIYAREMYE Gabriel HABUMUGISHA jean de Dieu State Key laboratory of Desert and Oasis Ecology Xinfiang Institute of Ecologg and Geography Chinese Academy of Sciences 818 Beijing road south Urumqi Xinjiang 830011 China China University ofGeosciences （Wuhan） 388 Lumo Road Wuhan 430074 Hubei China Independent Institute of Lay Adventists ofKigali （INILAK） P O Box 6392 Kigali-Rwanda Institut Polytechnique de Byumba （IPB） PO Box 25 Byumba Rwanda

The primary purpose of this study was to assess water losses by evapotranspiration, evaporation and seepage in arid ***, evaporation and seepage are the main causes of water *** modeling water losses,a combination of Genetic Programming(GP),Penman-Monteith(PM) and Penman combination model for measurement of evapotranspiration,evaporation and seepage has been *** results were found to be varying depending on how the evaporation and seepage phenomena are *** results show that that there is an improvement in reducing evapotranspiration,evaporation and seepage losses in arid and semi-arid region.

关键词： Arid zone Evaporation Evapotranspiration Seepage Water losses China

Differences in egg hatching time between cyclical and obligate parthenogenetic lineages of aphids

在线全文

学校读者我要写书评

暂无评论

Insect Science 2019年第1期26卷 135-141页

作者： Charles-Antoine Dedryver Joel Bonhomme jean-Francois Le Gallic jean-Christophe Simon Unite Mixte de Recherche IGEPP 1349 INRAIAgrocampus OuestlUniversite Rennes 1Le Rheu cedexFrance

Many aphid species exhibit a variation in reproductive mode which is influenced by winter climate regimes,with cyclical parthenogenetic (CP)lines dominating in cold winter areas (because they produce cold-resistant eggs)and obligate parthenogenetic (OP) ones in mild winter regions (because of their parthenogenetic overwintering).Genetic studies on several aphid species have shown that the OP trait can be transmitted during sexual events involving the 2 types of *** genetic system could be considered as a local safeguarding mechanism for OP alleles in case severe frost would have killed all parthenogenetically overwintering ***,this strategy would only be efficient in restoring local polymorphism in breeding systems if the newly hatched OP recombinants remain competitive over their CP *** this study we compared egg hatching sequences of CP and OP F1 clones from several crosses obtained for 2 cereal aphid species,Sitobion avenae (constant 5℃,8 h of light)and Rhopalosiphum padi (winter outdoor conditions).For ***,we obtained F1 offspring from 6 crosses, involving 4 clones while in *** F1 were obtained from 11 crosses involving 14 clones. We showed that in both species proportions of OP clones were higher in the first half of the progeny relative to the second *** addition,F1 OP clones hatched in the mean about a week earlier than their CP sibs,which gives them a demographic advantage at the start of the growth *** then discussed the consequences of this fitness advantage for the maintenance and spread of the OP trait in aphid populations.

关键词： asexuality diapauses genetic variation insects overwintering strategies reproductive mode