期刊文献+
共找到22篇文章
< 1 2 >
每页显示 20 50 100
How accurately can we predict synthesis cross sections of superheavy elements? 被引量:3
1
作者 David Boilley Bartholome Cauchois +3 位作者 Hongliang Lu Anthony Marchix Yasuhisa Abe Caiwan Shen 《Nuclear Science and Techniques》 SCIE CAS CSCD 2018年第12期15-20,共6页
Synthesis of superheavy elements beyond oganesson is facing new challenges as new target–projectile combinations are necessary. Guidance from models is thus expected for future experiments. However, hindered fusion m... Synthesis of superheavy elements beyond oganesson is facing new challenges as new target–projectile combinations are necessary. Guidance from models is thus expected for future experiments. However, hindered fusion models are not well established and predictions in the fission barriers span few MeVs. Consequently, predictions are not reliable. Strategies to constrain both fusion hindrance and fission barriers are necessary to improve the predictive power of the models. But, there is no hope to get an accuracy better than one order of magnitude in fusion–evaporation reactions leading to superheavy elements synthesis. 展开更多
关键词 超重元素 合成 预言 十字节 地能 模型 精确性 数量级
下载PDF
Highly active Pd containing EMT zeolite catalyst for indirect oxidative carbonylation of methanol to dimethyl carbonate 被引量:3
2
作者 Chunzheng Wang Weisong Xu +3 位作者 Zhengxing Qin Hailing Guo Xinmei Liu Svetlana Mintova 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第1期191-201,I0007,共12页
Palladium containing EMT zeolite catalyst(Pd/EMT) was prepared and used for the indirect oxidative carbonylation of methanol to dimethyl carbonate(DMC).The EMT zeolite was employed as a new catalyst support and compar... Palladium containing EMT zeolite catalyst(Pd/EMT) was prepared and used for the indirect oxidative carbonylation of methanol to dimethyl carbonate(DMC).The EMT zeolite was employed as a new catalyst support and compared with the conventional Pd containing FAU zeolite catalyst(Pd/FAU).The Pd/EMT in contrast to the Pd/FAU catalyst exhibited high intrinsic activity with the turnover frequency of 0.25 s^(-1) vs.0.11 s^(-1).The Pd/EMT catalyst showed high CO conversion of 82% and DMC selectivity of 79%,that maintained for at least 130 h,while the activity of the Pd/FAU catalyst rapidly deteriorated within 12 h.The enhanced interactions between Pd and EMT zeolite inhibited the sintering of palladium clusters and maintained the Pd2+ active sites in the Pd/EMT catalyst.The stabilization of the mono-dispersed Pd clusters within the EMT zeolite is paramount to the excellent performance of the catalyst for the indirect oxidative carbonylation of methanol to DMC. 展开更多
关键词 EMT PALLADIUM Stability CARBONYLATION Dimethyl carbonate
下载PDF
Emotions and performance in rugby
3
作者 Mickael Campo Stéphane Champely +3 位作者 Andrew MLane Elisabeth Rosnet Claude Ferrand Benoit Louvet 《Journal of Sport and Health Science》 SCIE 2019年第6期595-600,共6页
Purpose:This study investigated emotion-performance relationships in rugby union.We identified which emotions rugby players experienced and the extent to which these emotions were associated with performance,consideri... Purpose:This study investigated emotion-performance relationships in rugby union.We identified which emotions rugby players experienced and the extent to which these emotions were associated with performance,considering how emotions unfold over the course of a game,and whether the game was played at home or away.Methods:Data were gathered from 22 professional male rugby union players using auto-confrontation interviews to help identify situations within games when players experienced intense emotions.We assessed the intensity of emotions experienced before each discrete performance and therefore could assess the emotion-performance relationship within a competition.Results:Players identified experiencing intense emotions at 189 time-points.Experts in rugby union rated the quality of each performance at these 189 time-points on a visual analog scale.A Linear Mixed Effects model to investigate emotion-performance relationships found additive effects of game location,game time,and emotions on individual performance.Conclusion:Results showed 7 different pre-performance emotions,with high anxiety and anger associating with poor performance.Future research should continue to investigate emotion-performance relationships during performance using video-assisted recall and use a measure of performance that has face validity for players and coaches alike. 展开更多
关键词 EMOTION GAME location GAME time Linear Mixed Effects model MULTILEVEL analysis Performance assessment TEAM SPORT
下载PDF
Determination of Integrated Molar Absorption Coefficients for Gaseous Phenol Infrared Bands and Influence of Water Vapor on Their Values
4
作者 Thomas Onfroy Olivier Marie 《American Journal of Analytical Chemistry》 2019年第1期9-22,共14页
The integrated molar absorption coefficients for ν(OH) (3655 cm-1), δ(OH) (Q branch at 1176 cm-1 or whole bands), [ν(CCring) + δ(OH)] (Q branch at 1344 cm-1 or whole bands) and γ(CH) (752 cm-1) were determined at... The integrated molar absorption coefficients for ν(OH) (3655 cm-1), δ(OH) (Q branch at 1176 cm-1 or whole bands), [ν(CCring) + δ(OH)] (Q branch at 1344 cm-1 or whole bands) and γ(CH) (752 cm-1) were determined at 342 K, by recording infrared spectra of pure gaseous phenol at different partial pressure (from 0 to 33 Pa). The integrated molar absorption coefficients (ε) values were obtained with a good reproducibility and the relative uncertainty on the given values is below 2%. The influence of water on the integrated molar absorption coefficients of phenol has been investigated in a large range of nwater/nphenol values (from 0.5 to 6.1 and from 44 to 94) using distinct setups. The infrared spectra of a gas mixture containing a constant amount of phenol and different amount of water were recorded (closed cell) whereas in dynamic condition (under flow) the water partial pressure was kept constant at 1.3 kPa and the phenol partial pressure was increased from 0 to 30 Pa. It is here demonstrated that, at 342 or 355 K, the presence of water does not affect the epsilon values of δ(OH) and [ν(CCring) + δ(OH)] bands. 展开更多
关键词 PHENOL GAS INTEGRATED MOLAR Absorption COEFFICIENTS DETERMINATION IR Spectroscopy Phenol-Water Interaction PHENOL GAS Quantification
下载PDF
Estimation of Sea Level Rise on the West African Coasts: Case of Senegal, Mauritania and Cape Verde
5
作者 Cheikh Ahmed Tidiane Sarr Mouhamadou Moustapha Mbacké Ndour +1 位作者 Mahdi Haddad Issa Sakho 《International Journal of Geosciences》 2021年第2期121-137,共17页
The advent of technology in the world has led to enormous, varying economic and social changes. Those changes have influenced the climate balance, which leads to global temperature rise, hence oceanic expansion and me... The advent of technology in the world has led to enormous, varying economic and social changes. Those changes have influenced the climate balance, which leads to global temperature rise, hence oceanic expansion and melting glaciers. These various phenomena caused the variation in the mean sea level. Thus, in this study we have evaluated that variation from the instrumental recordings of the tide gauges available in the region, which led us to choose the tide gauges of Dakar (Senegal), Nouakchott (Mauritania) and Palmeira (Cape Verde). The analysis of the tidal series began with the test of presence or absence of significant trends in the series using the Man-Kendall method followed by the decomposition of these series using the SSA, ARIMA and SLT techniques, which would result in the trend, seasonality and residues. The results of this analysis show a variation of 1.52 mm/year, 4.51 mm/year and 20.08 mm/year respectively for the Dakar, Palmeira and Nouakchott tide gauges. 展开更多
关键词 Sea Level Trend Analysis Senegal Palmeira Nouakchott
下载PDF
Fixed points of n-valued maps on surfaces and the Wecken property a configuration space approach 被引量:1
6
作者 GONCALVES Daciberg Lima GUASCHI John 《Science China Mathematics》 SCIE CSCD 2017年第9期1561-1574,共14页
Abstract In this paper, we explore the fixed point theory of n-vaiued maps using configuration spaces and braid groups, focusing on two fundamental problems, the Wecken property, and the computation of the Nielsen num... Abstract In this paper, we explore the fixed point theory of n-vaiued maps using configuration spaces and braid groups, focusing on two fundamental problems, the Wecken property, and the computation of the Nielsen number. We show that the projective plane (resp. the 2-sphere S2) has the Wecken property for n-valued maps for all n ∈N (resp. all n ≥ 3). In the case n = 2 and S2, we prove a partial result about the Wecken property. We then describe the Nielsen number of a non-split n-valued map φ : X → X of an orientable, compact manifold without boundary in terms of the Nielsen coincidence numbers of a certain finite covering q: )→ X with a subset of the coordinate maps of a lift of the n-valued split map → q : →X. 展开更多
关键词 multivalued maps fixed points Wecken property Nielsen numbers BRAIDS configuration space
原文传递
Metal-free regioselective construction of 2-aryl-2H-tetrazol-5-yl difluoromethylene phosphonates 被引量:1
7
作者 Shi-Jing Zhai Dominique Cahard +1 位作者 Fa-Guang Zhang Jun-An Ma 《Chinese Chemical Letters》 SCIE CAS CSCD 2022年第2期863-866,共4页
Three bench-stable difluoromethylene phosphonate hydrazones were prepared from simple diethyl(difluoromethyl)phosphonate within two steps in good yields. The [3 + 2] cycloaddition reaction of these diazo precursors wi... Three bench-stable difluoromethylene phosphonate hydrazones were prepared from simple diethyl(difluoromethyl)phosphonate within two steps in good yields. The [3 + 2] cycloaddition reaction of these diazo precursors with aryl diazonium salts has been accomplished under metal-free conditions with exclusive regioselectivity. This transformation provides practical access to a broad panel of 2-aryl-2 H-tetrazol-5-yl difluoromethylene phosphonates, including the corresponding derivatives of amino acid(phenylalanine) and drug cores(Pomalidomide and Lapatinib fragment). 展开更多
关键词 TETRAZOLE Cycloaddition Difluoromethylene phosphonate Regioselectivity Diazonium salt
原文传递
Earthworms promote greater richness and abundance in the emergence of plant species across a grassland-forest ecotone 被引量:1
8
作者 Julia Clause Sébastien Barot Estelle Forey 《Journal of Plant Ecology》 SCIE 2016年第6期703-711,共9页
Aims Chalk grasslands are subject to vegetation dynamics that range from species-rich open grasslands to tall and encroached grasslands,and woods and forests.In grasslands,earthworms impact plant communities and ecosy... Aims Chalk grasslands are subject to vegetation dynamics that range from species-rich open grasslands to tall and encroached grasslands,and woods and forests.In grasslands,earthworms impact plant communities and ecosystem functioning through the modification of soil physical,chemical and microbiological properties,but also through their selective ingestion and vertical transportation of seeds from the soil seed bank.Laboratory experiments showed that seed-earthworm interactions are species specific,but little is known on the impact of seed-earthworm interactions in the field.The overall aim of this study was to better understand seed-earthworm interactions and their impact on the plant community.First we analyzed the composition of seedlings emerging from casts after earthworm ingestion.Then we compared seedling composition in casts to the plant composition of emerging seedlings from the soil and of the aboveground vegetation along four stages of the secondary succession of chalk grasslands.Methods Four stages of the secondary succession of a chalk grassland—from open sward to woods—were sampled in Upper Normandy,France,in February 2010.Within each successional stage(×3 replicates),we sampled the standing vegetation,soil seed bank at three soil depths(0-2,2-5 and 5-10 cm)and earthworm surface casts along transects.Soil and cast samples were water sieved before samples were spread onto trays and placed into a greenhouse.Emerging seedlings were counted and identified.Effect of successional stage and origin of samples on mean and variability of abundance and species richness of seedlings emerging from casts and soil seed banks were analyzed.Plant compositions were compared between all sample types.We used generalized mixed-effect models and a distance-based redundancy multivariate analysis.Important Findings Seedling abundance was always higher in earthworm casts than in the soil seed bank and increased up to 5-fold,4-fold and 3.5-fold,respectively,in the tall grassland,woods and encroached grassland compared to the soil surface layer.Species richness was also higher in earthworm casts than in the soil seed bank in all successional stages,with a 4-fold increase in the encroached grassland.The plant composition of the standing vegetation was more similar to that of seedlings from casts than to that of seedlings from the soil seed bank.Seedlings diversity emerging from casts in the tall and encroached grasslands tended toward the diversity found in woods.Our results indicate that earthworms may promote the emergence of seedlings.We also suggest that the loss of some plant species in the seed bank and the tall grass vegetation in intermediary successional stages modify the local conditions and prevent the further establishment of early-successional plant species. 展开更多
关键词 aboveground-belowground interactions earthworm casts seedling emergence secondary succession seed bank
原文传递
GaAs-chip-based mid-infrared supercontinuum generation 被引量:1
9
作者 Geoffroy Granger Myriam Bailly +13 位作者 Hugo Delahaye Cristian Jimenez Idris Tiliouine Yann Leventoux Jean-Christophe Orlianges Vincent Couderc Bruno Gérard Rezki Becheker Said Idlahcen Thomas Godin Ammar Hideur Arnaud Grisard Eric Lallier Sébastien Février 《Light(Science & Applications)》 SCIE EI CSCD 2023年第11期2443-2450,共8页
The mid-infrared spectral region opens up new possibilities for applications such as molecular spectroscopy with high spatial and frequency resolution.For example,the mid-infrared light provided by synchrotron sources... The mid-infrared spectral region opens up new possibilities for applications such as molecular spectroscopy with high spatial and frequency resolution.For example,the mid-infrared light provided by synchrotron sources has helped for early diagnosis of several pathologies.However,alternative light sources at the table-top scale would enable better access to these state-of-the-art characterizations,eventually speeding up research in biology and medicine.Midinfrared supercontinuum generation in highly nonlinear waveguides pumped by compact fiber lasers represents an appealing alternative to synchrotrons.Here,we introduce orientation-patterned gallium arsenide waveguides as a new versatile platform for mid-infrared supercontinuum generation.Waveguides and fiber-based pump lasers are optimized in tandem to allow for the group velocities of the signal and the idler waves to match near the degeneracy point.This configuration exacerbates supercontinuum generation from 4 to 9μm when waveguides are pumped at 2750 nm with few-nanojoule energy pulses.The brightness of the novel mid-infrared source exceeds that of the thirdgeneration synchrotron source by a factor of 20.We also show that the nonlinear dynamics is strongly influenced by the choice of waveguide and laser parameters,thus offering an additional degree of freedom in tailoring the spectral profile of the generated light.Such an approach then opens new paths for high-brightness mid-infrared laser sources development for high-resolution spectroscopy and imaging.Furthermore,thanks to the excellent mechanical and thermal properties of the waveguide material,further power scaling seems feasible,allowing for the generation of watt-level ultra-broad frequency combs in the mid-infrared. 展开更多
关键词 waveguide PUMPED PUMP
原文传递
m^(6)A Profile Dynamics Indicates Regulation of Oyster Development by m^(6)A-RNA Epitranscriptomes 被引量:1
10
作者 Lorane Le Franc Bruno Petton +1 位作者 Pascal Favrel Guillaume Rivière 《Genomics, Proteomics & Bioinformatics》 SCIE CAS CSCD 2023年第4期742-755,共14页
The N6-methylation of RNA adenosines(N6-methyladenosine,m^(6)A)is an important regulator of gene expression with critical implications in vertebrate and insect development.However,the developmental significance of epi... The N6-methylation of RNA adenosines(N6-methyladenosine,m^(6)A)is an important regulator of gene expression with critical implications in vertebrate and insect development.However,the developmental significance of epitranscriptomes in lophotrochozoan organisms remains unknown.Using methylated RNA immunoprecipitation sequencing(MeRIP-seq),we generated transcriptome-wide m^(6)A-RNA methylomes covering the entire development of the oyster from oocytes to juveniles.Oyster RNA classes display specific m^(6)A signatures,with messenger RNAs(mRNAs)and long non-coding RNAs(lncRNAs)exhibiting distinct profiles and being highly methylated compared to transposable element(TE)transcripts.Epitranscriptomes are dynamic and correspond to the chronological steps of development(cleavage,gastrulation,organogenesis,and metamorphosis),with minimal mRNA and lncRNA methylation at the morula stage followed by a global increase.mRNA m^(6)A levels are correlated with transcript levels,and shifts in methylation profiles correspond to expression kinetics.Differentially methylated transcripts cluster according to embryo-larval stages and bear the corresponding developmental functions(cell division,signal transduction,morphogenesis,and cell differentiation).The m^(6)A level of TE transcripts is also regulated and peaks during the gastrulation.We demonstrate that m^(6)A-RNA methylomes are dynamic and associated with gene expression regulation during oyster development.The putative epitranscriptome implication in the cleavage,maternal-to-zygotic transition,and cell differentiation in a lophotrochozoan model brings new insights into the control and evolution of developmental processes. 展开更多
关键词 RNA methylation Transcription EMBRYO METAMORPHOSIS EVO-DEVO
原文传递
The periodic unfolding method for the heat equation in perforated domains 被引量:1
11
作者 DONATO Patrizia YANG ZhanYing 《Science China Mathematics》 SCIE CSCD 2016年第5期891-906,共16页
We study the heat equation with non-periodic coefficients in periodically perforated domains with a homogeneous Neumann condition on the holes. Using the time-dependent unfolding method, we obtain some homogenization ... We study the heat equation with non-periodic coefficients in periodically perforated domains with a homogeneous Neumann condition on the holes. Using the time-dependent unfolding method, we obtain some homogenization and corrector results which generalize those by Donato and Nabil(2001). 展开更多
关键词 heat equations perforated domains homogenization correctors periodic unfolding method
原文传递
Machine learning for integrating combustion chemistry in numerical simulations 被引量:1
12
作者 Huu-Tri Nguyen Pascale Domingo +1 位作者 Luc Vervisch Phuc-Danh Nguyen 《Energy and AI》 2021年第3期330-338,共9页
A strategy based on machine learning is discussed to close the gap between the detailed description of combustion chemistry and the numerical simulation of combustion systems.Indeed,the partial differential equations ... A strategy based on machine learning is discussed to close the gap between the detailed description of combustion chemistry and the numerical simulation of combustion systems.Indeed,the partial differential equations describ-ing chemical kinetics are stiffand involve many degrees of freedom,making their solving in three-dimensional unsteady simulations very challenging.It is discussed in this work how a reduction of the computing cost by an order of magnitude can be achieved using a set of neural networks trained for solving chemistry.The ther-mochemical database used for training is composed of time evolutions of stochastic particles carrying chemical species mass fractions and temperature according to a turbulent micro-mixing problem coupled with complex chemistry.The novelty of the work lies in the decomposition of the thermochemical hyperspace into clusters to facilitate the training of neural networks.This decomposition is performed with the Kmeans algorithm,a local principal component analysis is then applied to every cluster.This new methodology for combustion chemistry reduction is tested under conditions representative of a non-premixed syngas oxy-flame. 展开更多
关键词 Combustion chemistry Micro-mixing modeling Principal component analysis Artificial neural network Chemistry reduction
原文传递
法国烟雾血管病临床实践指南 被引量:5
13
作者 D. Herve(著) M. Kossorotoff(著) +25 位作者 D. Bresson(著) T. Blauwblomme(著) M. Carneiro(著) E. Touze(著) F. Proust(著) I. Desguerre(著) S. Alamowitch(著) J.-P. Bleton(著) A. Borsali(著) E. Brissaud F.Brunelle(著) L. Calviere(著) M. Chevignard(著) G. Geffroy-Greco(著) S. Faesch(著) M.-O. Habert(著) H.De Larocque(著) P. Meyer(著) S. Reyes L. Thines(著) E. Tournier-Lasserve(著) H.Chabriat 郝方斌(译) 张勇(译) 韩聪(译) 段炼(译) 《国际脑血管病杂志》 2018年第5期321-330,共10页
1序言 1.1制定机构 本指南在法国卫生部的组织下由法国脑部和眼部罕见血管疾病中心(reference center for rare vascular diseases of the brain and eye,CERVCO)与法国儿童卒中中心联合起草。
关键词 临床实践指南 法国 血管病 DISEASES 烟雾 BRAIN 血管疾病 卒中中心
原文传递
Simultaneous 3D temperature and velocity field measurements of micro-flow with laser-induced fluorescence and micro-digital holographic particle tracking velocimetry: Numerical study
14
作者 姚龙超 吴学成 +5 位作者 阳静 吴迎春 高翔 陈玲红 Gérard Gréhan 岑可法 《Chinese Optics Letters》 SCIE EI CAS CSCD 2015年第7期105-109,共5页
We propose a method for simultaneous 3D temperature and velocity measurement of a micro-flow field. The 3D temperature field is characterized with two-color laser-induced fluorescence particles which are tracked with ... We propose a method for simultaneous 3D temperature and velocity measurement of a micro-flow field. The 3D temperature field is characterized with two-color laser-induced fluorescence particles which are tracked with micro-digital holographic particle tracking velocimetry. A diffraction-based model is applied to analyze defo- cused particles to determine the intensity ratio of two fluorescent dyes on the particle. The model is validated with experimental images. As the result shows that the intensity ratio nearly remains unchanged with respect to depth positions, defocused particles can be used as 3D temperature sensors. Numerical work is carried out to check the method, and 3D temperature and velocity field in a 120 μm × 120 μm× 80 μm test volume are retrieved. 展开更多
关键词 Fluorescence HOLOGRAPHY Laser optics Laser produced plasmas Numerical methods VELOCIMETERS Velocity
原文传递
Extraction of physical Schottky parameters using the Lambert function in Ni/AIGaN/GaN HEMT devices with defined conduction phenomena
15
作者 O.Latry A.Divay +1 位作者 D.Fadil P.Dherbécourt 《Journal of Semiconductors》 EI CAS CSCD 2017年第1期95-99,共5页
Electrical characterization analyses are proposed in this work using the Lambert function on Schottky junctions in GaN wide band gap semiconductor devices for extraction of physical parameters.The Lambert function is ... Electrical characterization analyses are proposed in this work using the Lambert function on Schottky junctions in GaN wide band gap semiconductor devices for extraction of physical parameters.The Lambert function is used to give an explicit expression of the current in the Schottky junction.This function is applied with defined conduction phenomena,whereas other work presented arbitrary(or undefined)conduction mechanisms in such parameters' extractions.Based upon AlGaN/GaN HEMT structures,extractions of parameters are undergone in order to provide physical characteristics.This work highlights a new expression of current with defined conduction phenomena in order to quantify the physical properties of Schottky contacts in AlGaN/GaN HEMT transistors. 展开更多
关键词 GAN Schottky junction conduction mechanisms Lambert function parameters extraction
原文传递
A Survey of the Homotopy Properties of Inclusion of Certain Types of Configuration Spaces into the Cartesian Product
16
作者 Daciberg Lima GONCALVES John GUASCHI 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2017年第6期1223-1246,共24页
Let X be a topological space.In this survey the authors consider several types of configuration spaces,namely,the classical(usual)configuration spaces F_n(X)and D_n(X),the orbit configuration spaces F_n^G(X)and F_n^G(... Let X be a topological space.In this survey the authors consider several types of configuration spaces,namely,the classical(usual)configuration spaces F_n(X)and D_n(X),the orbit configuration spaces F_n^G(X)and F_n^G(X)/S_nwith respect to a free action of a group G on X,and the graph configuration spaces F_n~Γ(X)and F_n~Γ(X)/H,whereΓis a graph and H is a suitable subgroup of the symmetric group S_n.The ordered configuration spaces F_n(X),F_n^G(X),F_n~Γ(X)are all subsets of the n-fold Cartesian product ∏_1~nX of X with itself,and satisfy F_n^G(X)?F_n(X)?F_n~Γ(X)?∏_1~nX.If A denotes one of these configuration spaces,the authors analyse the difference between A and ∏_1~nXfrom a topological and homotopical point of view.The principal results known in the literature concern the usual configuration spaces.The authors are particularly interested in the homomorphism on the level of the homotopy groups of the spaces induced by the inclusionι:A-→∏_1~nX,the homotopy type of the homotopy fibre I_ιof the mapιvia certain constructions on various spaces that depend on X,and the long exact sequence in homotopy of the fibration involving I_ιand arising from the inclusionι.In this respect,if X is either a surface without boundary,in particular if X is the 2-sphere or the real projective plane,or a space whose universal covering is contractible,or an orbit space S^k/Gof the k-dimensional sphere by a free action of a Lie group G,the authors present recent results obtained by themselves for the first case,and in collaboration with Golasi′nski for the second and third cases.The authors also briefly indicate some older results relative to the homotopy of these spaces that are related to the problems of interest.In order to motivate various questions,for the remaining types of configuration spaces,a few of their basic properties are described and proved.A list of open questions and problems is given at the end of the paper. 展开更多
关键词 Configuration space Equivariant configuration space FIBRATION Homotopy fibre K(π 1)space Braid groups
原文传递
Homogenization of Elliptic Problems with Quadratic Growth and Nonhomogenous Robin Conditions in Perforated Domains
17
作者 Imen CHOURABI Patrizia DONATO 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2016年第6期833-852,共20页
This paper deals with the homogenization of a class of nonlinear elliptic problems with quadratic growth in a periodically perforated domain. The authors prescribe a Dirichlet condition on the exterior boundary and a ... This paper deals with the homogenization of a class of nonlinear elliptic problems with quadratic growth in a periodically perforated domain. The authors prescribe a Dirichlet condition on the exterior boundary and a nonhomogeneous nonlinear Robin condition on the boundary of the holes. The main difficulty, when passing to the limit, is that the solution of the problems converges neither strongly in L^2(Ω) nor almost everywhere in Ω. A new convergence result involving nonlinear functions provides suitable weak convergence results which permit passing to the limit without using any extension operator.Consequently, using a corrector result proved in [Chourabi, I. and Donato, P., Homogenization and correctors of a class of elliptic problems in perforated domains, Asymptotic Analysis, 92(1), 2015, 1–43, DOI: 10.3233/ASY-151288], the authors describe the limit problem, presenting a limit nonlinearity which is different for the two cases, that of a Neumann datum with a nonzero average and with a zero average. 展开更多
关键词 HOMOGENIZATION Elliptic problems Quadratic growth Nonhomogeneous Robin boundary conditions Perforated domains
原文传递
Cumulative unsupervised multi-domain adaptation for Holstein cattle re-identification
18
作者 Fabian Dubourvieux Guillaume Lapouge +2 位作者 Angélique Loesch Bertrand Luvison Romaric Audigier 《Artificial Intelligence in Agriculture》 2023年第4期46-60,共15页
In dairy farming,ensuring the health of each cow and minimizing economic losses requires individual monitoring,achieved through cow Re-Identification(Re-ID).Computer vision-based Re-ID relies on visually dis-tinguishi... In dairy farming,ensuring the health of each cow and minimizing economic losses requires individual monitoring,achieved through cow Re-Identification(Re-ID).Computer vision-based Re-ID relies on visually dis-tinguishing features,such as the distinctive coat patterns of breeds like Holstein.However,annotating every cow in each farm is cost-prohibitive.Our objective is to develop Re-ID methods applicable to both labeled and unlabeled farms,accommodating new individuals and diverse environments.Un-supervised Domain Adaptation(UDA)techniques bridge this gap,transferring knowledge from labeled source domains to unlabeled target domains,but have only been mainly designed for pedestrian and vehicle Re-ID applications.Our work introduces Cumulative Unsupervised Multi-Domain Adaptation(CUMDA)to address challenges of lim-ited identity diversity and diverse farm appearances.CUMDA accumulates knowledge from all domains,enhanc-ing specialization in known domains and improving generalization to unseen domains.Our contributions include a CUMDA method adapting to multiple unlabeled target domains while preserving source domain performance,along with extensive cross-dataset experiments on three cattle Re-ID datasets.These experiments demonstrate significant enhancements in source preservation,target domain specialization,and generalization to unseen domains. 展开更多
关键词 Re-identification Domain adaptation Holstein cattle Unsupervised learning Monitoring
原文传递
Origin of superconductivity in hole doped SrBiO_(3) bismuth oxide perovskite from parameter-free first-principles simulations
19
作者 Julien Varignon 《npj Computational Materials》 SCIE EI CSCD 2023年第1期2044-2052,共9页
The recent discovery of nickel oxide superconductors have highlighted the importance of first-principles simulations forunderstanding the formation of the bound electrons at the core of superconductivity. Nevertheless... The recent discovery of nickel oxide superconductors have highlighted the importance of first-principles simulations forunderstanding the formation of the bound electrons at the core of superconductivity. Nevertheless, superconductivity in oxides isoften ascribed to strong electronic correlation effects that density functional theory (DFT) cannot properly take into account,thereby disqualifying this technique. Being isostructural to nickel oxides, Sr_(1-x)K_(x)BiO_(3) superconductors form an ideal testbed forunveiling the lowest theory level needed to model complex superconductors and the underlying pairing mechanism yieldingsuperconductivity. Here I show that parameter-free DFT simulations capture all the experimental features and related quantities of Sr_(1-x)K_(x)BiO_(3) superconductors, encompassing the prediction of an insulating to metal phase transition upon increasing the K dopingcontent and of an electron-phonon coupling constant of 1.22 in sharp agreement with the experimental value of 1.3 ± 0.2. Theproximity of a disproportionated phase is further demonstrated to be a prerequisite for superconductivity in bismuthates. 展开更多
关键词 SUPERCONDUCTIVITY BISMUTH parameter
原文传递
Sb_(2)Te_(3)/graphite nanocomposite: A comprehensive study of thermal conductivity
20
作者 Subarna Das P.Singha +11 位作者 V.A.Kulbachinskii V.G.Kytin Gangadhar Das S.Janaky A.K.Deb Sudip Mukherjee A.Maignan S.Hebert R.Daou Chandrabhas Narayana S.Bandyopadhyay Aritra Banerjee 《Journal of Materiomics》 SCIE EI 2021年第3期545-555,共11页
Thermoelectric performance largely depends on the reduction of lattice thermal conductivity(kL).The study of the thermal conductivity(k)of a Sb_(2)Te_(3)/graphite nanocomposite system demonstrates-40%reduction in kL w... Thermoelectric performance largely depends on the reduction of lattice thermal conductivity(kL).The study of the thermal conductivity(k)of a Sb_(2)Te_(3)/graphite nanocomposite system demonstrates-40%reduction in kL with graphite incorporation.A plausible explanation of intrinsic low kL observed in Sb_(2)Te_(3) based system is presented by modeling experimental specific heat(Cp)data.Raman spectroscopy measurement combined to X-Ray diffraction data confirms the presence of graphite as separate phase in the composite sample.It is found that phonon scattering dominates heat transport mechanism in the nanostructured Sb_(2)Te_(3)/graphite composite.Large reduction in kL is accomplished by intensifying scattering rate of phonons via various sources.Graphite introduces effective scattering sources,i.e.,defects of different dimensionalities in synthesized nanocomposite sample.Furthermore,graphite mediates phonon-phonon coupling and enhances lattice anharmonicity,which causes an intrinsic scattering of phonons with all frequencies in the Sb_(2)Te_(3)/graphite nanocomposite sample.Dislocation density and phonon anharmonicity of the synthesized samples are estimated from in depth analysis of temperature dependent synchrotron powder diffraction and Raman spectroscopic data.kL value as low as 0.8 W m1 K1 at 300 K,achieved with graphite dispersion in Sb_(2)Te_(3) based composite system makes the present comprehensive study an interesting concept to be developed in thermoelectric materials. 展开更多
关键词 Thermoelectric systems Thermal conductivity PHONONS X-ray powder diffraction Raman spectroscopy Specific heat measurements
原文传递
上一页 1 2 下一页 到第
使用帮助 返回顶部