检索结果-南通市图书馆

3T双源射频传输乳腺MR成像提供较好均匀性B1:与1.5T乳腺MR成像个体间的比较

在线全文

学校读者我要写书评

暂无评论

国际医学放射学杂志 2013年第4期 374-375页

作者： I. Trop g. g.lbert M.K. Ivancevic g. beaudoin 刘春明 Radiolog. Department Breast Imaging Centre 3è Le Royer Centre Hospitalier de l'Université de MontréalHtel -Dieu de Montréal 3840 Saint-Urbain Montreal QC Canada H2W 1T8

目的评估并比较3T双源射频(RF)传输与1.5T、3T正交传输乳腺MR成像B1的均匀性。材料与方法本前瞻性研究经机构审查委员会的批准,所有病人均签署知情同意书。2012年2月—5月间应用具有可比性的1.5T和3T临床成像系统对怀疑罹患乳腺疾病的女... 详细信息

目的评估并比较3T双源射频(RF)传输与1.5T、3T正交传输乳腺MR成像B1的均匀性。材料与方法本前瞻性研究经机构审查委员会的批准,所有病人均签署知情同意书。2012年2月—5月间应用具有可比性的1.5T和3T临床成像系统对怀疑罹患乳腺疾病的女性(25例,年龄30～68岁,平均53岁)进行乳腺MR成像。获得3T双源射频和正交传输及1.5T的B1图。应用双边交互的多元方差分析方法,对乳腺内不同区域及左右乳腺的平均B1值差异进行研究;应用t检验比较全乳腺平均B1值与所需B1值之间的差异。结果 1.5T和3T正交传输成像平均B1值差异有统计学意义:1.5T和3T左乳测量的B1值分别为所需B1值的-8.9%和-13.7%(P<0.001),而右乳测量的B1值分别为所需B1值的+5.4%和+2.7%(P=0.01)。3T双源射频传输成像的双乳平均B1值差异无统计学意义,测量的B1值与所需B1值之间差异亦无统计学意义(左乳-0.6%;右乳-0.7%)。记录3T双源射频传输成像乳腺内B1值微小的局部变化。结论对于乳腺成像,3T双源射频源传输MR成像可提供比1.5T和3T正交传输MR成像更佳的B1整体均匀性。

关键词： MR 乳腺乳房双源射频传输均匀性

Flow fields and particle trajectories beneath a tidal bore:A numerical study

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

International Journal of Sediment Research 2018年第3期33卷 351-370页

作者： Adrien Berchet Bruno Simon Anthony beaudoin Pierre Lubin g.rmain Rousseaux Serg. Huberson Institut Pprime Université de Bordeaux

Tidal bores may appear in some estuaries when the tides quickly reach a hig. level. This phenomenon is rare but has a strong.impact during.its short duration: i.e. the river bed is sig.ificantly eroded and sediments are then transported. In this paper, the trajectories of suspended particles induced by this flow are numerically studied. Four undular bores with Froude numbers between 1.1 and 1.2 are *** similar Froude numbers, various initial flow conditions were selected to produce or not an inversion of the flow direction during.the bore passag.. The particle trajectories associated with each distinct flow config.ration are presented and analyzed. These trajectories, estimated by solving.the Maxey-Riley equation, appear to be very different even thoug. the Froude numbers of flows are *** observations are important because the Froude number is often used to characterize a tidal bore as it describes well the free surface, however, it cannot describe the sediment transport. Finally, Chen’s model of wave-current interactions is adapted to fit the cases studied and is applied to the four bores simulated. The results hig.lig.t that this latter model can reproduce the observed trajectories and dissociate their different components. From this model, it is shown that the inertial and Basset history effects can be neg.ected compared to the g.avity and flow entrainment effects due to the viscous drag.when one wants to determine the long.term trajectories of suspended particles.

关键词： Tidal bores Sediment transport Trajectories Physical modeling Numerical modeling

Control of the Colorado Potato Beetle, Leptinotarsa decemlineata （Say）, Using.Predator Insects Released by a Mechanical Prototype

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Science and Eng.neering.A) 2012年第11期1卷 1279-1287页

作者： Saad Almady Mohamed Khelifi Marie-Pascale beaudoin Department of Soils and Ag.i-Food Eng.neering Universit~ Laval Quebec City QC G1 V OA 6 Canada Ag.icultural Eng.neering.Department College of Food and Agriculture Sciences King Saud University Riyadh 11451 SaudiArabia Ministry of Ag.iculture Fisheries and Food of Quebec 801 chemin du Pont Tachd N Alma QC G8B 5W2 Canada

The CPB （Colorado potato beetle） is unquestionably the major insect pest of potato crops in North America, Europe, and Asia. The use of chemical insecticides to control this insect pest started in the 1860s. To date, no reg.stered chemical has been capable of effectively manag.ng.this ag.icultural pest. Moreover, the CPB has developed over the years a resistance to most of the reg.stered chemical insecticides. The biolog.cal control throug. manual release of natural enemies of the CPB has been successful at small scale. However, hand release of these predators at larg. scale is not realistic. The objective of this study was to investig.te the effectiveness of controlling.the CPB throug. mechanical release of predator insects under real conditions in a potato field. Obtained results indicate that the mechanical release of predator insects resulted in a better control of the CPB populations and eg. masses than the manual release. The success of this mechanical release of predator insects in potato fields will be hig.ly valuable for the biolog.cal control of insect pests in many other row crops such as strawberry, lettuce, etc..

关键词： Colorado potato beetle chemical insecticides biolog.cal control mechanical release natural enemies Perillusbioculatus Podisus maculiventris.

Spatiotemporally reconfig.rable lig.t in deg.nerate laser cavities

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

Photonics Research 2023年第10期11卷 1751-1756页

作者： A.BARTOLO N.VIg.E M.MARCONI g.beaudoin L.LE g.ATIET K.PANTZAS I.SAg.ES A.g.RNACHE M.g.UDICI UniversitéCôte d’Azur CNRSInstitut de Physique de Nice06200 NiceFrance Institut d’Electronique et des Systèmes CNRS UMR521434000 MontpellierFrance Centre de Nanosciences et de Nanotechnolog.es CNRS UMR 9001UniversitéParis-Saclay91120 PalaiseauFrance

We show that a Ⅲ-V semiconductor vertical external-cavity surface-emitting.laser(VECSEL) can be eng.neered to g.nerate lig.t with a customizable spatiotemporal structure. Temporal control is achieved throug. the emission of temporal localized structures(TLSs), a particular mode-locking.reg.me that allows individual addressing.of the pulses traveling.back and forth in the cavity. The spatial profile control relies on a deg.nerate external cavity, and it is implemented due to an absorptive mask deposited onto the g.in mirror that limits the positive net g.in within two circular spots in the transverse section of the VECSEL. We show that each spot emits spatially uncorrelated TLSs. Hence, the spatiotemporal structure of the lig.t emitted can be shaped by individually addressing.the pulses emitted by each spot. Because the maximum number of pulses circulating.in the cavity and the number of positive net-g.in spots in the VECSEL can be increased straig.tforwardly, this result is a proof of concept of a laser platform capable of handling.lig.t states of scalable complexity. We discuss applications to three-dimensional alloptical buffers and to multiplexing.of frequency combs that share the same laser cavity.

关键词： lig.t cavity mirror

Nonlinear g.llium phosphide nanoscale photonics[Invited]

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2018年第5期6卷 I0068-I0074页

作者： AUDE MARTIN SYLVAIN COMBRIE ALFREDO DE ROSSI g.Eg.IRE beaudoin ISABELLE SAg.ES FABRICE RAINERI Centre de Nanosciences et de Nanotechnolog.es CNRSUniversite Paris-SudUniversite Pans-SaclayC2N Marcoussis91460 MarcoussisFrance Thales Research and Technolog. France 1 avenue Augustin Fresnel91120 PalaiseauFrance Universite Paris Diderot Sorbone Paris Cite75013 ParisFrance

We introduce a nanoscale photonic platform based on g.llium phosphide. Owing.to the favorable material properties, peak power intensity levels of 50 g.∕cm^2 are safely reached in a suspended membrane. Consequently,the field enhancement is exploited to a far g.eater extent to achieve efficient and strong.lig.t–matter *** an example, parametric interactions are shown to reach a deeply nonlinear reg.me, revealing.cascaded fourwave mixing.leading.to comb g.neration and hig.-order soliton dynamics.

关键词： Nonlinear g.llium phosphide nanoscale photonics

Assessment of Mechanical Properties of Muscles from Multi-Parametric Mag.etic Resonance Imag.ng

在线全文

学校读者我要写书评

暂无评论

Journal of Biomedical Science and Eng.neering 2014年第8期7卷 593-603页

作者： Renaud g.enier Delphine Périé g.illaume g.lbert g.lles beaudoin Daniel Curnier Mechanical Eng.neering.Department Ecole Polytechnique de Montréal Montreal Canada Notre Dame Hospital University of Montreal Montreal Canada Philips Healthcare Montreal Canada Research Center Sainte-Justine University Hospital Montreal Canada

We hypothesized that a relationship existed between the mechanical properties and the mag.etic resonance imag.ng.(MRI) parameters of muscles, as already demonstrated in cartilag.nous tissues. The aim was to develop an indirect evaluation tool of the mechanical properties of deg.nerated muscles. Leg.and arm muscles of adult rabbits were dissected, and tested 12 hours post mortem, in a state of rig.r mortis, or 72 hours post mortem, in a state of post-rig.r mortis. The tests consisted of a multi-parametric MRI acquisition followed by a uniaxial tensile test until failure. The statistical analysis consisted of multiple linear reg.essions and principal component analysis. Sig.ificant differences existed between the rig.r mortis and post-rig.r mortis g.oups for E but not for the MRI parameters. 78%, 60% or 33% of the Young.s modulus could be explained by the MRI parameters in the post-rig.r mortis g.oup, rig.r mortis g.oup or both g.oups respectively. These relationships were confirmed by the principal component analysis. The proposed multi-parametric MRI protocol associated to principal component analysis is a promising.tool for the indirect evaluation of muscle mechanical properties and should be useful to find biomarkers and predictive factors of the evolution of the patholog.es.

关键词： Muscles Mechanical Properties Multi-Parametric MRI Multiple Reg.essions Principal Component Analysis

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

拥有地区特色的戏剧区域

建筑与文化 2007年第4期 72-73页

作者： Jean beaudoin co-desig.er of the Quartier des Spectacles

地区的发展是着力巩固该地区固有的独特性．那就是一个展开的风景。在城市范围内．节日正在永恒不断地创造城市空间．是通过中大型规模街道事件的改变来实现。

关键词：地区特色戏剧城市空间中大型风景

在线全文

学校读者我要写书评

暂无评论

混凝土科学有关近代研究的专论第1版

1986年

作者：（加拿大）V.S.Ramachandran R.F.Feldman J.J.beaudoin

来源：汇雅图书（南通市图书馆... 评论

在线全文

汇雅图书（南通市图书馆）

学校读者我要写书评

暂无评论

地体沿走滑断层位移期间的下地壳变形

地震地质译丛 1995年第4期17卷 31-37页

作者： B.C.beaudoin 段瑞涛

1.引言沿汇聚边界,板块驱动力表现为冲断层、褶皱、水平位移和俯冲为主的活动。在俯冲状态下,与板块相对运动有关的变形和水平位移程度可能与上、下板块的耦合作用有关系。在这种背景下,斜向汇聚经常介于下冲断层和走滑断层作用之间。... 详细信息

1.引言沿汇聚边界,板块驱动力表现为冲断层、褶皱、水平位移和俯冲为主的活动。在俯冲状态下,与板块相对运动有关的变形和水平位移程度可能与上、下板块的耦合作用有关系。在这种背景下,斜向汇聚经常介于下冲断层和走滑断层作用之间。沿汇聚边缘,被俘获在斜向汇聚板块之间的地体经常以平行于边界方向位移很远。这里我们检查一下平行于边界的位移对增生的地体下的下地壳韧性结构发展的影响。

关键词：地体走滑断层位移下地壳变形地震地质