检索结果-南通市图书馆

Modelling of massive particulates for breakwater engineering using coupled FEMDEM and CFD

Particuology 2008年第6期6卷 572-583页

作者： John-Paul Lathama Antonio Munjiza Julian Mindel Jiansheng Xiang romain Guises Xavier Garcia Chris Pain Gerard Gorman Matthew Piggott Department of Earth Science and Engineering Imperial College London UK Department of Engineering Queen Mary London University London UK

The seaward slope of many breakwaters consists of thousands of interlocking units of rock or concrete comprising a massive granular system of large elements each weighing tens of tonnes. The dumped quarry materials in the core are protected by progressively coarser particulates. The outer armour layer of freely placed units is intended to both dissipate wave energy and remain structurally stable as strong flows are drawn in and out of the particulate core. Design guidance on the mass and shape of these units is based on empirical equations derived from scaled physical model tests. The main failure mode for armour layers exposed to severe storms is hydraulic instability where the armour units of concrete or rock are subjected to uplift and drag forces which can in turn lead to rocking, displacement and collisions sufficient to cause breakage of units. Recently invented armour unit designs making up such granular layered system owe much of their success to the desirable emergent properties of interlock and porosity and how these combine with individual unit structural strength and inertial mass. Fundamental understanding of the forces governing such wave-structure interaction remains poor. We use discrete element and combined finite-discrete element methods to model the granular solid skeleton of randomly packed units coupled to a CFD code which resolves the wave dynamics through an interface tracking technique. The CFD code exploits several methods including a compressive advection scheme, node movement, and general mesh optimization. We provide the engineering context and report progress towards the numerical modelling of instability in these massive granular systems.

关键词： Modelling DEM Wave-structure interaction Armour units Breakwater

来源：

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

ionic Species Affect the Self-Propulsion of Urease-Powered Micromotors

引用

Research 2020年第1期2020卷 349-362页

作者： Xavier Arque Xavier Andres Rafael Mestre Bernard Ciraulo Jaime Ortega Arroyo romain Quidant Tania Patino Samuel Sanchez institute for Bioengineering of Catalonia(iBEC) The Barcelona Institute of Science and Technology(BIST)Baldiri i Reixac 10-1208028 BarcelonaSpain institute of Photonic Sciences(iCFO) The Barcelona Institute of Science and TechnologyCarl Friedrich Gauss 308860 CastelldefelsBarcelonaSpain institucióCatalana de Recerca i Estudis Avançats(iCREA) Pg.Lluís Companys 2308010 BarcelonaSpain Chemistry Department University of RomeTor VergataVia della Ricerca Scientifica00133 RomeItaly

Enzyme-powered motors self-propel through the catalysis of in situ bioavailable fuels,which makes them excellent candidates for biomedical ***,fundamental issues like their motion in biological fluids and the understanding of the propulsion mechanism are critical aspects to be tackled before a future application in ***,we investigated the physicochemical effects of ionic species on the self-propulsion of urease-powered *** showed that the presence of PBS,NaOH,NaCl,and HEPES reduced self-propulsion of urease-powered micromotors pointing towards iondependent mechanisms of *** studied the 3D motion of urease micromotors using digital holographic microscopy to rule out any motor-surface interaction as the cause of motion decay when salts are present in the *** order to protect and minimize the negative effect of ionic species on micromotors’performance,we coated the motors with methoxypolyethylene glycol amine(mPEG)showing higher speed compared to noncoated motors at intermediate ionic *** results provide new insights into the mechanism of urease-powered micromotors,study the effect of ionic media,and contribute with potential solutions to mitigate the reduction of mobility of enzyme-powered micromotors.

关键词： holographic salts catalysis

来源：

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

Limit point buckling of a finite beam on a nonlinear foundation

引用

Theoretical & Applied Mechanics Letters 2014年第3期4卷 18-24页

作者： romain Lagrange Massachusetts institute of Technology Department of MathematicsCambridgeMA 02139-4307 USA

in this paper, we consider an imperfect finite beam lying on a nonlinear foundation, whose dimensionless stiffness is reduced from 1 to k as the beam deflection increases. Periodic equilibrium solutions are found analytically and are in good agreement with a numerical resolution, suggesting that localized buckling does not appear for a finite beam. The equilibrium paths may exhibit a limit point whose existence is related to the imperfection size and the stiffness parameter k through an explicit condition. The limit point decreases with the imperfection size while it increases with the stiffness parameter. We show that the decay/growth rate is sensitive to the restoring force model. The analytical results on the limit load may be of particular interest for engineers in structural mechanics.

关键词： buckling imperfection finite beam nonlinear foundation limit point

来源：

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

罗曼·罗兰语录

引用

时代英语（高一版） 2024年第2期 1-1页

作者：罗曼·罗兰不详

没有伟大的品格,就没有伟大的人,甚至也没有伟大的艺术家、伟大的行动者。

关键词：罗曼·罗兰行动者艺术家

来源：

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

Sexual health and fertility for individuals with inflammatory bowel disease

引用

World Journal of Gastroenterology 2019年第36期25卷 5423-5433页

作者： romain Leenhardt Pauline Riviere Patrick Papazian isabelle Nion-Larmurier Guillaume Girard David Laharie Philippe Marteau Sorbonne Universite Hepatologie Gastroenterologie et Saint Antoine IBD NeTwork APHP Hopital St Antoine Paris 75012 Ile-de-France France CHU de Bordeaux Hopital Haut-Leveque Service d'Hepatogastroenterologie CMC Magellan Bordeaux 33604 Pessac France Hopital Bichat Service des maladies infectieuses et tropicales APHP Paris 75018 France Service de gynecologie obstetrique Hopital Armand Trousseau Paris 75012 Ile-de-France France

The impact of a chronic disease such as inflammatory bowel disease (iBD) on sexual functioning and body image can significantly impair the quality of life of patients. This review considers the sexual and fertility aspects of iBD patients and their daily management. Modern iBD healthcare management should include appropriate communication on sexuality and consider psychological, physiological, and biological issues. Patients with iBD have less children than the general population, and voluntary childlessness is frequent. The most influential factors reported by iBD patients who experience fertility alteration are psychological and surgery-related problems. Pregnancy is a major concern for patients, and any pregnancy for iBD patients should be closely followed-up to keep the chronic disease in a quiescent state. Preconceptional consultation is of great help.

关键词： inflammatory bowel disease Crohn’s disease Ulcerative colitis Fertility Pregnancy Sexuality

来源：

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

Uncontrolled Drilling: Exposing a Global Threat to Groundwater Sustainability

引用

Journal of Water Resource and Protection 2012年第9期4卷 746-749页

作者： romain Chesnaux Université du Québec à Chicoutimi

Untold numbers of boreholes are drilled into the earth’s crust every year. Most constitute a potential threat to groundwater quality by creating a preferred pathway for contaminant migration. Some solutions, including “well-pooling”, are proposed to better protect groundwater resources through the efficient management of boreholes.

关键词： Groundwater Resources Contamination Drilling Well-Pooling

来源：

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

Diuretic and antioxidant activities of the aqueous extract of leaves of Cassia occidentalis(Linn.) in rats

引用

Asian Pacific Journal of Tropical Medicine 2015年第9期8卷 673-681页

作者： Théophile Dimo Fidèle Ntchapda Joseph Barama David romain Kemeta Azambou Paul Faustin Seke Etet Department of Animal Biology and Physiology Faculty of Science University of Yaoundé 1 Department of Biological Sciences Faculty of Science University of Ngaoundéré Department of Basic Health Sciences College of Applied Medical Sciences Qassim University

Objective: To assess the putative diuretic and antioxidant properties of Cassia occidentalis(C. occidentalis) leaves' aqueous extract. Methods: Adult rats were administered with C. occidentalis leaves aqueous extract acutely(24-h) and subchronically(7 d), at doses 80, 160, 240, 320, and 400 mg/kg(per os). Negative control group received only an equivalent volume of distilled water, while the two positive control groups received the diuretic drugs furosemide(20 mg/kg, i.p.) and hydrochlorothiazide(HCTZ, 20 mg/kg, i.p.). Urinary elimination of electrolytes in response to treatments was evaluated, together with changes in concentrations of creatinine, urea, aldosterone, glucose, and albumin in urine and plasma. Various urinary indicators of kidney function and plasmatic markers of oxidative stress were also assessed. Results: The acute administration of C. occidentalis increased the urinary excretion of 107.58% at the higher dose tested, compared to negative control. The reference drugs furosemide and HCTZ induced increases of 84.27 % and 48.05 %, respectively. Acutely, the extract induced Na+ and Cl- elimination, whereas subchronically an increase in K+ elimination was also observed. The extract also improved the kidney function indexes and oxidative stress markers. These effects were dose-dependent and comparable with positive control observations. Conclusions: Our i ndings strongly suggest that C. occidentalis aqueous extract has diuretic and antioxidant activities, and deserves further studies considering the potential for the treatment of hypertension.

关键词： Cassia occidentalis Diuretic Antioxidant Urine kidney function Electrolytes

来源：

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

40 Gb/s NRZ-DQPSK data wavelength conversion with amplitude regeneration using four-wave mixing in a quantum dash semiconductor optical amplifier

引用

Frontiers of Optoelectronics 2016年第3期9卷 341-345页

作者： Michael J. CONNELLY Lukasz KRZCZANOWiCZ Pascal MOREL Ammar SHARAiHA Francois LELARGE romain BRENOT Siddharth JOSHi Sophie BARBET Optical Communications Research Group Department of Electronic and Computer Engineering University of Limerick Limerick Ireland Lab-STiCC UMR CNRS 6285 Ecole Nationale d'Ingenieurs de Brest CS 73862 29238 Brest Cedex 3 France Alcatel Thales iii-V Laboratory Route Departementale 128 91767 Palaiseau France

Differential quadrature phase shift keying （DQPSK） modulation is attractive in high-speed optical communications because of its resistance to fiber non-linearities and more efficient use of fiber bandwidth compared to conventional intensity modulation schemes. Because of its wavelength conversion ability and phase preservation, semiconductor optical amplifier （SOA） four- wave mixing （FWM） has attracted much attention. We experimentally study wavelength conversion of 40 Gbit/s （20 Gbaud） non-return-to-zero （NRZ）-DQPSK data using FWM in a quantum dash SOA with 20 dB gain and 5 dBm output saturation power. Q factor improvement and eye diagram reshaping is shown for up to 3 nm pump-probe detuning and is superior to that reported for a higher gain bulk SOA.

关键词： differential quadrature phase shift keying (DQPSK) phase modulation quantum-dash semiconductor optical amplifier (SOA) four-wave mixing (FWM) wavelength conversion

来源：

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

Geodynamic evolution of the Tethyan lithosphere as recorded in the Spontang Ophiolite,South Ladakh ophiolites(NW Himalaya,india)

引用

Geoscience Frontiers 2022年第1期13卷 326-349页

作者： Mallika K.Jonnalagadda Mathieu Benoit Shivani Harshe romain Tilhac Raymond A.Duraiswami Michel Grégoire Nitin R.Karmalkar interdisciplinary School of Science Savitribai Phule Pune UniversityPune 411007India Department of Geology Savitribai Phule Pune UniversityPune 411007India Géosciences Environnement Toulouse CNRS-CNES-IRD-UniversitéPaul SabatierObservatoire Midi Pyrénées31400 ToulouseFrance instituto Andaluz de Ciencias de la Tierra(iACT) CSIC–Universidad de Granada18100 ArmillaGranadaSpain Vice-Chancellor’s Office Savitribai Phule Pune UniversityPune 411007India

The Spontang Ophiolite complex represents the most complete ophiolite sequence amongst the South Ladakh ophiolites and comprises mantle rocks(depleted harzburgites,dunites and minor lherzolites)as well as crustal rocks(basalt,isotropic gabbros,layered gabbros etc.).in the present study,detailed geochemistry(whole rock as well as mineral chemistry)and Sr-Nd isotopic analyses of thirty-six ultramaficmafic samples have been attempted to constraint the evolution and petrogenetic history of the Tethyan oceanic ***,trace-element and REE patterns of the peridotites and their minerals indicate that the lherzolites experienced lower degrees of partial melting resembling abyssal peridotites(at higher temperatures,TREE=$1216℃)than the harzburgites(6%–8%versus 15%–17%).Elevated eNd(t)and variable^(87) Sr/^(86) Sr(t)ratios along with REE patterns suggest that the Spontang mafic rocks display N-MORB affinity with negligible participation of oceanic sediments in their genesis are originated from a depleted upper mantle with little contribution from subduction-related ***-type Neotethyan oceanic crust is associated with the earliest phase of subduction(of older Jurassic age)through which a younger intra-oceanic island arc(Spong arc)subsequently *** REE display typical U-shaped patterns,suggesting that these rocks have been metasomatized by LREE-enriched *** the other side,mafic rocks are characterized by heterogeneous(Nb/La)PMand(Hf/Sm)PMand relatively homogeneous eNd(t),indicating interaction of subduction-related melts with the upper mantle during the initiation of subduction,in Early Cretaceous times.

关键词： Peridotites Mafic rocks Partial melting Metasomatism Ladakh

来源：

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

Evolution of a Holocene banner bank controlled by morphodynamics and structural setting of a macrotidal coast: Saint-Brieuc Bay (NW-Europe)

引用

Geoscience Frontiers 2021年第5期12卷 166-181页

作者： Kalil Traoréa David Menier Erwan Gensac Pascal Le Roy Clément Lambert Paul Bessin Kevin Pedoja Anne Duperret romain Le Gall Laboratoire Géoscience Océan UMR 6538CNRSUniversitéBretagne SudCampus de Tohannic56000 VannesFrance Laboratoire Géoscience Océan UMR 6538CNRSIUEMUniversitéBretagne Occidentale29280 PlouzanéFrance Laboratoire de Planétologie et Géodynamique UMR 6112CNRSLe Mans UniversitéAvenue Olivier Messiaen72085 Le Mans CEDEX 9France Laboratoire Morphodynamique Continentale et Côtière UMR 6143CNRSUniversitéCaen Normandiecampus 12-4Rue des Tilleuls14000 Caen cedexFrance Laboratoire Ondes et Milieux Complexes UMR 6294CNRSUniversitéLe Havre Normandie53 rue de PronyCS8054076058 Le Havre cedexFrance

The morphology and internal structure of the Horaine Bank(Bay of Saint-Brieuc,NW France)are described based on multibeam echosounder and high-resolution seismic datasets coupled with vibro-core *** Horaine Bank shows large-scale bedforms in the lee of a submerged rocky shoal,which allowed defining it as a Banner *** internal structure of the sandbank reveals four seismic units(U1-U4)on a Cambrian basement(U0).The basal unit U1 is interpreted as reworked lowstand fluvial sediments those infilled micro incised valleys during a rise in sea *** unit is overlain by paleo-coastal barrier sand-spit(U2)whose development was controlled by swell in the context of a rapid rise in sea *** successive prograding unit(U3)is interpreted as flooding deposits in continuity with unit *** unit U4 is characterized by oblique reflectors oriented in two opposite *** last unit,dated post 3500 yr BP,corresponds to migrating dunes superimposed on the bank and observable in the high-resolution bathymetric *** strong correlation between tidal currents and the apparent clockwise migration of dune crests suggests the presence of a tidal gyre controlling the present-day dynamics of most of the Horaine bank *** study proposes a new model for the construction of banner banks characterized by the gradual transition of a sand spit to a banner bank during marine transgression and ensuing hydrodynamic variability.

关键词： Sand banks Banner bank Holocene climate Geomorphology Sea level rise Tidal gyre

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：