检索结果-南通市图书馆

Key features of numerical models for the FE-simulation of deep tunnel advance by the NATM

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Underground Space 2024年第1期14卷 357-376页

作者： Peter Gamnitzer Matthias Neuner Magdalena Schreter-Fleischhacker Alexander dummer Thomas Mader stefan Smaniotto Gunter Hofstetter Unit of Strength of Materials and Structural Analysis Institute of Basic Sciences in Engineering SciencesUniversitat InnsbruckTechnikerstraβe 13Innsbruck A-6020Austria

In the present work,important aspects of time-dependent nonlinear 3d finite element(FE)models for deep tunnel advance by the New Austrian Tunneling Method(NATM),characterized by repeated sequences of excavation,securing,and idle periods,are discussed on the example of a 3d finite element model of a stretch of the Brenner Base Tunnel,which is currently constructed between Austria and *** material models are utilized for representing the surrounding rock mass and the shotcrete *** on the finite element model,strategies for the efficient implementation into a parallel distributed memory numerical code are *** are essential to achieve reasonable computation times for numerical simulations of tunneling based on large 3d FE *** particular,the implementation of the construction procedure,parallel computing and communication specific details,and efficient linear solvers for the global equation system within the incremental-iterative Newton–Raphson scheme are ***,possible extensions of the material models for rock mass and shotcrete,used in the 3d FE model,are *** concern(i)a gradient-enhanced model for transversely isotropic rock and rock mass,taking into account hardening and softening behavior and(ii)the extension of the shotcrete model to nonlinear creep and damage due to *** possible benefits of the model extensions in numerical simulations of tunneling by the NATM are discussed.

关键词： NATM Finite element model Rock Shotcrete damage-plasticity model

Fetal lung growth predicts the risk for early-life respiratory infections and childhood asthma

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Pediatrics 2024年第5期20卷 481-495页

作者： dimitra E.Zazara Olympia Giannou Steven Schepanski Mirja Pagenkemper Anastasios d.Giannou Maike Pincus Ioannis Belios stefan Bonn Ania C.Muntau Kurt Hecher Anke diemert Petra Clara Arck division for Experimental Feto-Maternal Medicine Department of Obstetrics and Fetal MedicineUniversity Medical Center Hamburg-Eppendorf(UKE)Martinistraße 5220251HamburgGermany University Children’s Hospital UKEHamburgGermany Computer Engineering and Informatics department Polytechnic SchoolUniversity of PatrasPatrasGreece Institute of developmental Neurophysiology Center for Molecular Neurobiology Hamburg(ZMNH)UKEHamburgGermany department of Obstetrics and Fetal Medicine UKEHamburgGermany department of General Visceral and Thoracic SurgeryUKEHamburgGermany Section of Molecular Immunology and Gastroenterology Ⅰ.Department of MedicineUKEHamburgGermany Pediatrics and Pediatric Pneumology Practice BerlinGermany Institute of Medical Systems Biology ZMNHUKEHamburgGermany Hamburg Center for Translational Immunology UKEHamburgGermany

Background Early-life respiratory infections and asthma are major health burdens during *** predicting an increased risk for early-life respiratory diseases are ***,we identified the predictive value of ultrasound-monitored fetal lung growth for the risk of early-life respiratory infections and *** Fetal lung size was serially assessed at standardized time points by transabdominal ultrasound in pregnant women participating in a pregnancy *** between fetal lung growth and respiratory infections in infancy or early-onset asthma at five years were ***-learning models relying on extreme gradient boosting regressor or classifier algorithms were developed to predict respiratory infection or asthma risk based on fetal lung *** model development and validation,study participants were randomly divided into a training and a testing group,respectively,by the employed *** Enhanced fetal lung growth throughout pregnancy predicted a lower early-life respiratory infection *** sex was associated with a higher risk for respiratory infections in *** lung growth could also predict the risk of asthma at five years of *** designed three machine-learning models to predict the risk and number of infections in infancy as well as the risk of early-onset *** models’R2 values were 0.92,0.90 and 0.93,respectively,underscoring a high accuracy and agreement between the actual and predicted *** variables included known risk factors and novel predictors,such as ultrasound-monitored fetal lung *** Sonographic monitoring of fetal lung growth allows to predict the risk for early-life respiratory infections and asthma.

关键词： Asthma Child risk Early-life respiratory infections Prenatal lung development Sexual dimorphism

EVA NEXUS-Phaco performance study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2024年第8期17卷 1447-1452页

作者： Lukas Feldhaus Andreas Ohlmann stefan Kassumeh Siegfried Priglinger Wolfgang Mayer department of Ophthalmology University HospitalLudwig-Maximilians-University MunichMunich 80336Germany

AIM:To investigate a novel phacoemulsification system“EVA NEXUS”(d.O.R.C.,dutch Opthalmic Research Center)in comparison to the existing system“EVA”in clinical *** to compare both phacoemulsification systems in terms of efficiency,safety and postoperative inflammatory ***:In this study standardized cataract surgery was performed on both eyes of the study participant,using the“EVA system”(control group,n=20)on one eye and the“EVA NEXUS system”(intervention group,n=20)on the other *** patients with cataract LOCS Grading 1-3 and no accompanying eye diseases were included in this study.A total of 20 patients were included in this study,with each treatment arm including 20 *** surgery a 0.1 mL aqueous humor sample was collected 1min after phacoemulsification to measure the total prostaglanin E2 concentrations using an enzyme-linked immunosorbent *** endothelial cell count,visual and refractive outcomes,and anterior chamber flare were evaluated preoperatively,and 1d,1wk,and 3mo ***:There were no statistically significant differences between both groups regarding intraoperative safety parameters including effective phacoemulsification time(P=0.904),balanced saline solution flow(P=0.701)and total surgery time(P=0.565).Postoperative prostaglandin E2 levels,anterior chamber flare as well as endothelial cell loss tended to be lower in the NEXUS-Group,however not being statistically significant(P=0.718;0.164;0.486).Both systems provided similar clinical outcomes,regarding best corrected visual acuity and refractive parameters,showing no statistically significant differences between both ***:Both systems show a high level of safety and efficency with similar results in terms of safety parameters including postoperative inflammatory activity and endothelial cell loss as well as visual and refractive *** statistically not significant,the EVA NEXUS system tends to cause less postoperative inflammatio

关键词： cataract surgery phacoemulsification fluidics instrument

deformable microlaser force sensing

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第6期13卷 1196-1209页

作者： Eleni dalaka Joseph SHill Jonathan H.H.Booth Anna Popczyk stefan R.Pulver Malte C.Gather Marcel Schubert Centre of Biophotonics SUPASchool of Physics and AstronomyUniversity of St AndrewsNorth HaughSt AndrewsUK Humboldt Centre for Nano-and Biophotonics Department of ChemistryUniversity of CologneKölnGermany School of Psychology and Neuroscience University of St AndrewsSt Mary’s QuadSouth StreetSt AndrewsUK Institute for Bioengineering of Catalonia BarcelonaSpain

Mechanical forces are key regulators of cellular behavior and function,affecting many fundamental biological processes such as cell migration,embryogenesis,immunological responses,and pathological *** force sensors and imaging techniques have been developed to quantify these otherwise invisible forces in single cells and in ***,current techniques rely heavily on high-resolution microscopy and do not allow interrogation of optically dense tissue,reducing their application to 2d cell cultures and highly transparent biological ***,we introduce dEFORM,deformable microlaser force sensing,a spectroscopic technique that detects sub-nanonewton forces with unprecedented spatio-temporal *** is based on the spectral analysis of laser emission from dye-doped oil microdroplets and uses the force-induced lifting of laser mode degeneracy in these droplets to detect nanometer *** validation by atomic force microscopy and development of a model that links changes in laser spectrum to applied force,dEFORM is used to measure forces in 3d and at depths of hundreds of microns within tumor spheroids and late-stage drosophila *** furthermore show continuous force sensing with single-cell spatial and millisecond temporal resolution,thus paving the way for non-invasive studies of biomechanical forces in advanced stages of embryogenesis,tissue remodeling,and tumor invasion.

关键词： invasion otherwise hundreds

Influence of symmetric and asymmetric rolling on texture evolution of work-hardened AA 5xxx aluminium alloy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2024年

作者： Matja? Godec stefan Zaefferer Jakob Kraner ?rtomir donik Irena Paulin Institute of Metals and Technology Max-Planck-Institut für Eisenforschung， Max-Planck-Strasse 1 Impol 2000 d.d.， Partizanska cesta 38

The textures and microstructures of hot- and cold-rolled sheets of an AA 5454 aluminium alloy were studied， with special attention paid to comparing the texture development for the symmetric and asymmetric cold rolling. Scanning electron microscopy with electron-backscatter diffraction was used to monitor the development of the microstructure in the differently deformed and additionally annealed samples. details of the formations and transformations of individual texture components occurring during the rolling processes were observed and discussed. The average grain sizes， textures and mechanical properties were correlated and explained for the symmetric and asymmetric cold-rolled samples. The asymmetric rolling is beneficial in terms of deep drawability because it reduces the planar anisotropy of the annealed material due to the decrease of the Cube， Goss， Rotated Cube and η- fibre texture components and the same time strengthens X1- and X2-fibre texture components which are shear texture components and improve deep drawability. during the asymmetric cold rolling， the temperature increases due to friction， triggering recrystallisation processes and leading to larger grains. It was also confirmed that asymmetric cold rolling uses less rolling force and consequently less energy to produce a final material with better formability， particularly earing.

关键词：

Optical probing of ultrafast laser-induced solid-to-overdense-plasma transitions

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第5期13卷 973-984页

作者： Yasmina Azamoum Georg Alexander Becker Sebastian Keppler Guillaume duchateau stefan Skupin Mickael Grech Fabrice Catoire Sebastian Hell Issa Tamer Marco Hornung Marco Hellwing Alexander Kessler Franck Schorcht Malte Christoph Kaluza GSI Helmholtzzentrum für Schwerionenforschung Planckstr.164291 DarmstadtGermany. Helmholtz Institute Jena Fröbelstieg 307743 JenaGermany. Institute of Optics and Quantum Electronics Friedrich-SchillerUniversität JenaMax-Wien-Platz 107743 JenaGermany. CEA-CESTA 15 Avenue des SablièresCS6000133116 Le BarpCedexFrance Institut Lumière Matière UMR 5306-CNRSUniversitéde Lyon 169622 VilleurbanneFrance. LULI CNRSCEASorbonne UniversitéInstitut Polytechnique de ParisPalaiseauFrance. Universitéde Bordeaux-CNRS-CEA CELIAUMR 5107 TalenceFrance

Understanding the solid target dynamics resulting from the interaction with an ultrashort laser pulse is a challenging fundamental multi-physics problem involving atomic and solid-state physics,plasma physics,and laser *** of the initial interplay of the underlying processes is essential to many applications ranging from lowpower laser regimes like laser-induced ablation to high-power laser regimes like laser-driven ion *** the properties of the so-called pre-plasma formed as the laser pulse’s rising edge ionizes the target is complicated from the theoretical and experimental point of view,and many aspects of this laser-induced transition from solid to overdense plasma over picosecond timescales are still open *** the one hand,laser-driven ion acceleration requires precise control of the pre-plasma because the efficiency of the acceleration process crucially depends on the target properties at the arrival of the relativistic intensity peak of the *** the other hand,efficient laser ablation requires,for example,preventing the so-called“plasma shielding”.By capturing the dynamics of the initial stage of the interaction,we report on a detailed visualization of the pre-plasma formation and ***-thin diamond-like carbon foils are shown to transition from solid to plasma during the laser rising edge with intensitiesd probe transmission measurements evidence sub-picosecond dynamics of an expanding plasma with densities above 10^(23)cm^(−3)(about 100 times the critical plasma density).The complementarity of a solid-state interaction model and kinetic plasma description provides deep insight into the interplay of initial ionization,collisions,and expansion.

关键词： laser acceleration solid

Exploring fs-laser irradiation damage subthreshold behavior of dielectric mirrors via electrical measurements

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

High Power Laser Science and Engineering 2024年第2期12卷 24-32页

作者： Petrisor Gabriel Bleotu Radu Udrea Alice dumitru Olivier Uteza Maria-diana Mihai dan Gh Matei daniel Ursescu stefan Irimiciuc Valentin Craciun Extreme Light Infrastructure-Nuclear Physics(ELI-NP) Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering(IFIN-HH)MagureleRomania doctoral School of Physics University of BucharestMagureleRomania LULI-CNRS CEAUniversite SorbonneEcole PolytechniqueInstitut Polytechnique de ParisPalaiseau CEDEXFrance Apel Laser IlfovRomania Aix-Marseille University CNRSLP3 UMR 7341MarseilleFrance Horia Hulubei National Institute for R&d in Physics and Nuclear Engineering(IFIN-HH) MagureleRomania University Politehnica of Bucharest BucharestRomania National Institute for Lasers Plasma and Radiation Physics MagureleRomania

With ultrafast laser systems reaching presently 10 PW peak power or operating at high repetition rates,research towards ensuring the long-term,trouble-free performance of all laser-exposed optical components is *** work is focused on providing insight into the optical material behavior at fluences below the standardized laser-induced damage threshold(LIdT)value by implementing a simultaneous dual analysis of surface emitted particles using a Langmuir probe(LP)and the target current(TC).HfO_(2) and ZrO_(2) thin films deposited on fused silica substrates by pulsed laser deposition at various O_(2) pressures for defect and stoichiometry control were irradiated by Gaussian,ultrashort laser pulses(800 nm,10 Hz,70 fs)in a wide range of *** TC and LP collected signals were in good agreement with the existing theoretical description of laser–matter interaction at an ultrashort time *** approach for an in situ LIdT monitoring system provides measurable signals for below-threshold irradiation conditions that indicate the endurance limit of the optical surfaces in the single-shot energy scanning *** LIdT value extracted from the LP-TC system is in line with the multipulse statistical analysis done with ISO 21254-2:2011(E).The implementation of the LP and TC as on-shot diagnostic tools for optical components will have a significant impact on the reliability of next-generation ultrafast and high-power laser systems.

关键词： HfO_(2) in situ detection Langmuir probe laser-induced damage threshold target current ZrO_(2)

Third-line rescue therapy for Helicobacter pylori infection

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

World Journal of Gastroenterology 2006年第15期12卷 2313-2319页

作者： Rossella Cianci Massimo Montalto Franco Pandolfi giovan Battista Gasbarrini giovanni Cammarota department of Internal Medicine Endoscopy Unit Catholic University of Sacred HeartRomeItaly

H pylori gastric infection is one of the most prevalent infectious diseases worldwide. The discovery that most upper gastrointestinal diseases are related to Hpylori infection and therefore can be treated with antibiotics is an important medical advance. Currently, a first-line triple therapy based on proton pump inhibitor （PPI） or ranitidine bismuth citrate （RBC） plus two antibiotics （darithromycin and amoxicillin or nitroimidazole） is recommended by all consensus conferences and guidelines. Even with the correct use of this drug combination, infection can not be eradicated in up to 23% of patients. Therefore, several second line therapies have been recommended. A 7 d quadruple therapy based on PPI, bismuth, tetracycline and metronidazole is the more frequently accepted. However, with second-line therapy, bacterial eradication may fail in up to 40% of cases. When Hpylori eradication is striclly indicated the choice of further treatment is controversial. Currently, a standard third-line therapy is lacking and various protocols have been proposed. Even after two consecutive failures, the most recent literature data have demonsbated that Hpylori eradication can be achieved in almost all patients, even when antibiotic susceptibility is not tested. different possibilities of empirical treatment exist and the available third-line strategies are herein reviewed.

关键词： Helicobacter pylori Third-line rescue therapy Antimicrobial resistance Levofloxacin Rifabutin Furazolidone doxycycline

Two-photon polymerization lithography for imaging optics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Extreme Manufacturing 2024年第4期6卷 21-60页

作者： Hao Wang Cheng-Feng Pan Chi Li Kishan S Menghrajani Markus A Schmidt Aoling Li Fu Fan Yu Zhou Wang Zhang Hongtao Wang Parvathi Nair Suseela Nair John You En Chan Tomohiro Mori Yueqiang Hu Guangwei Hu stefan A Maier Haoran Ren Huigao duan Joel K W Yang College of Mechanical and Vehicle Engineering Hunan UniversityChangsha 410082People's Republic of China Engineering Product development Singapore University of Technology and DesignSingapore 487372Singapore Greater Bay Area Institute for Innovation Hunan UniversityGuangzhou 511300People's Republic of China department of Electrical and Computer Engineering National University of Singapore4 Engineering Drive 3Singapore 117576Singapore School of Physics and Astronomy Faculty of ScienceMonash UniversityMelbourneVictoria 3800Australia Leibniz Institute of Photonic Technology 07745 JenaGermany Abbe Center of Photonics and Faculty of Physics FSU Jena07745 JenaGermany Otto Schott Institute of Material Research FSU Jena07745 JenaGermany Institute of Materials Research and Engineering A*STAR(Agency for Science Technology and Research)Singapore 138634Singapore Industrial Technology Center of Wakayama Prefecture Wakayama 6496261Japan School of Electrical and Electronic Engineering Nanyang Technological UniversitySingapore639798Singapore department of Physics Imperial College LondonLondon SW72AZUnited Kingdom

Optical imaging systems have greatly extended human visual capabilities,enabling the observation and understanding of diverse *** technologies span a broad spectrum of wavelengths from x-ray to radio frequencies and impact research activities and our daily *** glass lenses are fabricated through a series of complex processes,while polymers offer versatility and ease of ***,modern applications often require complex lens assemblies,driving the need for miniaturization and advanced designs with micro-and nanoscale features to surpass the capabilities of traditional fabrication ***-dimensional(3d)printing,or additive manufacturing,presents a solution to these challenges with benefits of rapid prototyping,customized geometries,and efficient production,particularly suited for miniaturized optical imaging *** 3d printing methods have demonstrated advantages over traditional counterparts,yet challenges remain in achieving nanoscale ***-photon polymerization lithography(TPL),a nanoscale 3d printing technique,enables the fabrication of intricate structures beyond the optical diffraction limit via the nonlinear process of two-photon absorption within liquid *** offers unprecedented abilities,***-free fabrication,micro-and nanoscale capabilities,and rapid prototyping of almost arbitrary complex 3d *** this review,we emphasize the importance of the criteria for optical performance evaluation of imaging devices,discuss material properties relevant to TPL,fabrication techniques,and highlight the application of TPL in optical *** the first panoramic review on this topic,it will equip researchers with foundational knowledge and recent advancements of TPL for imaging optics,promoting a deeper understanding of the *** leveraging on its high-resolution capability,extensive material range,and true 3d processing,alongside advances in materials,fabrication,and design,we en

关键词： two-photon polymerization lithography 3d printing additive manufacturing imaging optics and nanophotonics