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Passive mode-locking in semiconductor lasers with saturable absorbers bandgap shifted through quantum well intermixing

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Photonics Research 2014年第6期2卷 186-189页

作者： Vincenzo Pusino michael j.strain Marc Sorel School of Engineering University of Glasgow—Rankine BuildingOakfield AvenueGlasgow G128LTUK Institute of Photonics University of StrathclydeGlasgow G40NWUK

Passive mode-locking in semiconductor lasers in a Fabry–Perot configuration with a bandgap blueshift applied to the saturable absorber(SA)section has been experimentally *** the first time a fully post-growth technique,quantum well intermixing,was adopted to modify the material bandgap in the SA *** measurements showed not only an expected narrowing of the pulse width but also a significant expansion of the range of bias conditions generating a stable train of optical ***,the pulses from lasers with bandgap shifted absorbers presented reduced chirp and increased peak power with respect to the nonshifted case.

关键词： bandgap saturable lasers

All-optical tuning of a diamond micro-disk resonator on silicon

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Photonics Research 2020年第3期8卷 318-324页

作者： PAUL HILL CHARALAMBOS KLITIS BENOIT GUILHABERT MARC SOREL ERDAN GU MARTIN D.DAWSON michael j.strain Institute of Photonics Department of PhysicsTechnology and Innovation CentreUniversity of StrathclydeGlasgow G11RDUK Diamond Science and Technology Centre for Doctoral TrainingUniversity of WarwickCoventry CV47ALUK School of Engineering University of GlasgowGlasgow G128LTUK

High-quality integrated diamond photonic devices have previously been demonstrated in applications from nonlinear photonics to on-chip quantum ***,the small sample sizes of single crystal material available,and the difficulty in tuning its optical properties,are barriers to the scaling of these *** of these issues can be addressed by integrating micrometer-scale diamond devices onto host photonic integrated circuits using a highly accurate micro-assembly *** this work a diamond micro-disk resonator is integrated with a standard single-mode silicon-on-insulator waveguide,exhibiting an average loaded Q-factor of 3.1×10^4 across a range of spatial modes,with a maximum loaded Q-factor of 1.05×10^*** micrometer-scale device size and high thermal impedance of the silica interface layer allow for significant thermal loading and continuous resonant wavelength tuning across a 450 pm range using a milliwatt-level optical *** diamond-on-demand integration technique paves the way for tunable devices coupled across large-scale photonic circuits.

关键词： tuning resonator waveguide

Thermo-kinetic characteristics on stabilizing hetero-phase interface of metal matrix composites by crystal plasticity finite element method

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journal of Materials Science & Technology 2024年第2期169卷 53-67页

作者： Y.B.Zhang S.j.Song F.Liu State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China Analytical&Testing Center Northwestern Polytechnical UniversityXi’an 710072China

Using dislocation-based constitutive modeling in three-dimension crystal plasticity finite element(3D CPFE)simulations,co-deformation and instability of hetero-phase interface in different material systems were herein studied for polycrystalline metal matrix composites(MMCs).Local stress and strain fields in two types of 3layer MMCs such as fcc/fcc Cu-Ag and fcc/bcc Cu-Nb have been predicted under simple compressive ***,more severe strain-induced interface instability can be observed in the fcc/bcc systems than in the fcc/fcc systems upon refining to metallic nanolayered composites(MNCs).By detailed analysis of stress and strain localization,it has been demonstrated that the interface instability is always accompanied by high-stress concentration,i.e.,thermodynamic characteristics,or high strain prevention i.e.,kinetic characteristics,at the hetero-phase *** then follows that the thermodynamic driving forceG and the kinetic energy barrier Q during dislocation and shear banding can be adopted to classify the deformation modes,following the so-called thermo-kinetic *** by inserting a high density of high-energy interfaces into the Cu-Nb composites,such thermo-kinetic integration at the hetero-phase interface allows a successful establishment of MMCs with the high△G-high Q deformation mode,which ensures high hardening and uniform strain distri-bution,thus efficiently suppressing the shear band,stabilizing the hetero-phase interface,and obtaining an exceptional combination in strength and *** hetero-phase interface chosen by a couple of thermodynamics and kinetics can be defined as breaking the thermo-kinetic correlation and has been proposed for artificially designing MNCs.

关键词： Thermodynamics and kinetics Physics-based constitutive modeling Hetero-phase interface Crystal plasticity finite element

Superplasticity of fine-grained Mg-10Li alloy prepared by severe plastic deformation and understanding its deformation mechanisms

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journal of Magnesium and Alloys 2024年第1期12卷 316-331页

作者： H.T.jeong S.W.Lee W.j.Kim Department of Materials Science and Engineering Hongik UniversityMapo-guSangsu-dong 72-1Seoul 121-791Republic of Korea

The superplastic behavior and associated deformation mechanisms of a fine-grained Mg-10.1 Li-0.8Al-0.6Zn alloy(LAZ1011)with a grain size of 3.2μm,primarily composed of the BCCβphase and a small amount of the HCPαphase,were examined in a temperature range of 473 K to 623 *** microstructural refinement of this alloy was achieved by employing high-ratio differential speed *** best superplasticity was achieved at 523 K and at strain rates of 10^(-4)-5×10^(-4)s^(-1),where tensile elongations of 550±600%were *** the heating and holding stage of the tensile samples prior to tensile loading,a significant increase in grain size was observed at temperatures above 573 ***,it was important to consider this effect when analyzing and understanding the superplastic deformation behavior and *** the investigated strain rate range,the superplastic flow at low strain rates was governed by lattice diffusion-controlled grain boundary sliding,while at high strain rates,lattice diffusion-controlled dislocation climb creep was the rate-controlling deformation *** was concluded that solute drag creep is unlikely to *** the late stages of deformation at 523 K,it was observed that grain boundary sliding led to the agglomeration of theαphase,resulting in significant strain *** mechanism maps were constructed forβ-Mg-Li alloys in the form of 2D and 3D formats as a function of strain rate,stress,temperature,and grain size,using the constitutive equations for various deformation mechanisms derived based on the data of the current tests.

关键词： Magnesium-lithium alloy Superplasticity Severe plastic deformation Grain size Grain growth

Blood metal concentrations and cardiac structure and function in total joint arthroplasty patients

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World journal of Orthopedics 2024年第8期15卷 773-782页

作者： Peter C Brennan Stephanie M Peterson Thomas j O'Byrne Mariana L Laporta Cody C Wyles Paul j jannetto Garvan C Kane Maria Vassilaki Hilal Maradit Kremers Department of Orthopedic Surgery Mayo ClinicRochesterMN 55905United States Department of Quantitative Health Sciences Mayo ClinicRochesterMN 55905United States Department of Anesthesiology and Perioperative Medicine Mayo ClinicRochesterMN 55905United States Department of Laboratory Medicine and Pathology Mayo ClinicRochesterMN 55905United States Department of Cardiovascular Diseases Mayo ClinicRochesterMN 55905United States

BACKGROUND There is concern regarding potential long-term cardiotoxicity with systemic distribution of metals in total joint arthroplasty(TjA)*** To determine the association of commonly used implant metals with echocardiographic measures in TjA *** The study comprised 110 TjA patients who had a recent history of high chromium,cobalt or titanium *** underwent two-dimensional,three-dimensional,Doppler and speckle-strain transthoracic echocardiography and a blood draw to measure metal *** and sex-adjusted linear and logistic regression models were used to examine the association of metal concentrations(exposure)with echocardiographic measures(outcome).RESULTS Higher cobalt concentrations were associated with increased left ventricular end-diastolic volume(estimate 5.09;95%CI:0.02-10.17)as well as left atrial and right ventricular dilation,particularly in men but no changes in cardiac *** titanium concentrations were associated with a reduction in left ventricle global longitudinal strain(estimate 0.38;95%CI:0.70 to 0.06)and cardiac index(estimate 0.08;95%CI,-0.15 to-0.01).CONCLUSION Elevated cobalt and titanium concentrations may be associated with structural and functional cardiac changes in some *** studies are warranted to better understand the systemic effects of metals in TjA patients.

关键词： Total joint arthroplasty Metal-on-metal Cardiotoxicity Heart failure Echocardiography Cobalt

Effect of stress-dependent microannulus aperture on well leakage

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journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 1967-1976页

作者： Meng Meng Luke P.Frash j.William Carey Mohamed Mehana Wenfeng Li Bailian Chen Earth and Environmental Sciences Los Alamos National LaboratoryLos AlamosNMUSA

Debonding at the cement-casing interface is recognized as a principal failure mechanism leading to CO_(2) leakage in *** detachment gives rise to a microannulus,which notably possesses greater permeability than undamaged cement,undermining its sealing ***,the permeability of the microannulus is regarded as a uniform value throughout the ***,fundamentally,a microannulus is one type of fracture,and its gap or aperture size is affected by the effective *** this work,we developed a unique experimental *** equipment facilitates the curing of cement inside a steel casing,the formation of a microannulus between the casing and the cement,and the investigation of the fluid flow dynamics along the microannulus under laboratory-replicated in situ *** microannulus was formed by injecting fluid from one end of the setup,and receiving similar amount of fluid on the other end signified the development of the leakage ***,strain gauges affixed to the casing’s external surface yielded key information on the microannulus’s opening and *** observed a noticeable decline in microannulus hydraulic aperture(or permeability)in relation to effective stress and an exponential equation fits their *** findings also indicate a distinct behavior when comparing liquid CO_(2) with ***,it is easier for liquid CO_(2) to create the ***,the hydraulic aperture range for this microannulus(0.7-6 mm)is considerably smaller than that created by water flow(2-17 mm).Finally,we integrated the stressdependent microannulus aperture size into the combined analysis of well mechanical integrity and well *** outcomes consistently demonstrated that when factoring in the stress-dependent aperture sizes,the leakage rates are 3e5 times compared to a fixed aperture *** traditional assumption of a constant aperture significantly underestimates fluid leakage risks.

关键词： Microannulus Leakage assessment Aperture size Triaxial experiment Carbon sequestration

Towards efficient strain engineering of 2D materials:A four-points bending approach for compressive strain

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Nano Research 2024年第6期17卷 5317-5325页

作者： Hao Li Félix Carrascoso Ana Borrás Gloria P.Moreno Francisco j.Aparicio Ángel Barranco Andrés Castellanos Gómez Campus de Cantoblanco Instituto de Ciencia de Materiales de MadridC.Sor Juana Inés de la Cruz328049 MadridSpain Nanotechnology on Surfaces and Plasma Lab Instituto de Ciencia de Materiales de Sevilla(CSIC-Universidad de Sevilla).C/Americo Vespucio 49E-41092 SevilleSpain Departamento de Física Aplicada I Escuela Politécnica SuperiorUniversidad de Sevillac/Virgen deÁfrica 7E-41011 SevilleSpain

strain engineering,as a powerful strategy to tune the optical and electrical properties of two-dimensional(2D)materials by deforming their crystal lattice,has attracted significant interest in recent years.2D materials can sustain ultra-high strains,even up to 10%,due to the lack of dangling bonds on their surface,making them ideal brittle *** remarkable mechanical resilience,together with a strong strain-tunable band structure,endows 2D materials with a broad optical and electrical response upon ***,strain engineering based on 2D materials is restricted by their nanoscale and strain quantification *** this study,we have modified a homebuilt three-points bending apparatus to transform it into a four-points bending apparatus that allows for the application of both compressive and tensile strains on 2D *** approach allows for the efficient and reproducible construction of a strain system and minimizes the buckling effect caused by the van der Waals interaction by adamantane encapsulation *** results demonstrate the feasibility of introducing compressive strain on 2D materials and the potential for tuning their optical and physical properties through this approach.

关键词： uniaxial compressive strain polymer encapsulation differential reflectance spectroscopy exciton tunability

粉末冶金Al-5.6Zn-2Mg合金在热压缩过程中加工硬化特性及本构模型的比较

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journal of Central South University 2024年第2期31卷 346-368页

作者： KATIKA Harikrishna DAMODA R.K. DAVIDSON M.j. SEETHARAM R. KASAGANI Veera Venkata Nagaraju Department of Mechanical Engineering National Institute of TechnologyWarangal 506004India Department of Mechanical Engineering The Indian Institute of Information Technology Design and ManufacturingKurnool 518007India

在300~5000℃、应变速率为0.1~0.0001 s−1的条件下,在万能试验机上对Al-5.6Zn-2Mg铝合金进行热压缩试验,以确定动态再结晶开始时的加工硬化速率曲线σ_(c)(ε_(c))l以及关键特征σ_(c)(ε_(c))l、σ_(p)(ε_(p))和σ_(ss)与Z系数之间的... 详细信息

在300~5000℃、应变速率为0.1~0.0001 s−1的条件下,在万能试验机上对Al-5.6Zn-2Mg铝合金进行热压缩试验,以确定动态再结晶开始时的加工硬化速率曲线σ_(c)(ε_(c))l以及关键特征σ_(c)(ε_(c))l、σ_(p)(ε_(p))和σ_(ss)与Z系数之间的相关性。使用了四个本构模型,Arrhenius模型、改进的johnson-Cook模型(MjC)、改进的Zerilli-Armstrong模型(MZA)和开发的人工神经网络(ANN)。结果表明,ANN型模型和Arrhenius模型的相对误差的绝对平均值最低,分别为0.486%和3.36%,MZA型模型和MjC型模型的相对误差的绝对平均值较高,分别为8.84%和3.93%。由于Arrhenius模型能够处理各种因素之间的非线性关系,因此它被认为是最合适的预测模型,但在材料性质未知或实验数据有限的情况下,MjC模型可能是一种更简单的替代方法。MZA模型不适合估计热压缩时的流变应力。此外,训练最好的神经网络模型的预测性能最好,相对误差的绝对平均值为0.486%,R值为0.99。

关键词：加工硬化速率曲线本构建模热压缩 EBSD分析流变曲线

A comparative analysis of epidemiological characteristics of MERS-CoV and SARS-CoV-2 in Saudi Arabia

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Infectious Disease Modelling 2022年第3期7卷 473-485页

作者： Yehya Althobaity jianhong Wu michael j.Tildesley The Zeeman Institute for Systems Biology and Infectious Disease Epidemiology Research School of Life Sciences and Mathematics InstituteUniversity of WarwickCoventryCV47ALUnited Kingdom Laboratory for Industrial and Applied Mathematics Department of Mathematics and StatisticsYork UniversityTorontoOntarioM3J 1P3Canada Department of Mathematics Taif UniversityTaifP.O.Box 11099Saudi Arabia

In this study,we determine and compare the incubation duration,serial interval,pre-symptomatic transmission,and case fatality rate of MERS-CoV and COVID-19 in Saudi Arabia based on contact tracing data we acquired in Saudi *** date of infection and infector-infectee pairings are deduced from travel history to Saudi Arabia or exposure to confirmed *** incubation times and serial intervals are estimated using parametric models accounting for exposure interval *** estimations show that MERS-CoV has a mean incubation time of 7.21(95%CI:6.59–7.85)days,whereas COVID-19(for the circulating strain in the study period)has a mean incubation period of 5.43(95%CI:4.81–6.11)***-CoV has an estimated serial interval of 14.13(95%CI:13.9–14.7)days,while COVID-19 has an estimated serial interval of 5.1(95%CI:5.0–5.5)*** COVID-19 serial interval is found to be shorter than the incubation time,indicating that pre-symptomatic transmission may occur in a significant fraction of transmission *** conclude that during the COVID-19 wave studied,at least 75%of transmission happened prior to the onset of *** CFR for MERS-CoV is estimated to be 38.1%(95%CI:36.8–39.5),while the CFR for COVID-191.67%(95%CI:1.63–1.71).This work is expected to help design future surveillance and intervention program targeted at specific respiratory virus outbreaks,and have implications for contingency planning for future coronavirus outbreaks.

关键词： MERS-CoV SARS-CoV-2 Incubation period Serial interval Pre-symptomatic transmission Case fatality rate