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Influence of extrusion temperature on microstructure and mechanical properties of mg-4Y-4Sm-0.5Zr alloy

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Transactions of Nonferrous metals Society of China 2010年第7期20卷 1311-1315页

作者：李大全王渠东丁文江 J.J.BLANDIN m.suéry National Engineering Research Center for Nonferrous metals Composites General Research Institute for Nonferrous Metals National Engineering Research Center of Light Alloys Net Forming State Key Laboratory of Metal Matrix CompositesSchool of Materials Science and EngineeringShanghai Jiao Tong University Universitéde Grenoble Grenoble INPScience et Ingénieriedes Matériaux et Procédés(SIMAP) CNRS UMR 5266UJFBP 4638402 Saint-Martin d'Héres CedexFrance

The solution-treated mg-4Y-4Sm-0.5Zr alloy was extruded at temperatures from 325℃ to 500℃.Dynamic recrystallization(DRX) completely occurs when the alloy is extruded at 350℃and *** grains of the extruded alloy are obviously refined by the occurrence of *** average grain size of the extruded alloy increases with increasing the extrusion temperature,leading to a slight decrease of the ultimate tensile strength(UTS) and the yield strength(YS) .On the contrary,the UTS and YS of the extruded and aged alloy increase with increasing the extrusion *** of UTS of 400 mPa,YS larger than 300 mPa and elongation(EL) of 7%are achieved after extrusion at 400℃ and ageing at 200℃ for 16 *** grain refinement and precipitation are efficient strengthening mechanisms for the mg-4Y-4Sm-0.5Zr alloy.

关键词： mg-Y-Sm-Zr alloy extrusion heat treatment ageing mechanical properties

Oxygen uptake response to switching stairs exercise by non-parametric modeling

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Control Theory and Technology 2024年第2期22卷 315-325页

作者： Hairong Yu Chenyu Zhang Kai Cao Hamzah m.Alqudah Steven Weidong su Key Laboratory of Child Development and Learning Science of ministry of Education and the School of Biological Science and medical Engineering Southeast UniversityNanjing210096JiangsuChina College of Artificial Intelligence and Big Data for medical Science Shandong First Medical University and Shandong Academy of Medical SciencesJinan250117ShandongChina Faculty of Engineering and Information Technology University of Technology SydneyUltimoNSW2007Australia

Oxygen uptake plays a crucial role in the evaluation of endurance performance during exercise and is extensively utilized for metabolic assessment. This study records the oxygen uptake during the exercise phase (i.e., ascending or descending) of the stair exercise, utilizing an experimental dataset that includes ten participants and covers various exercise periods. Based on the designed experiment protocol, a non-parametric modeling method with kernel-based regularization is generally applied to estimate the oxygen uptake changes during the switching stairs exercise, which closely resembles daily life activities. The modeling results indicate the effectiveness of the non-parametric modeling approach when compared to fixed-order models in terms of accuracy, stability, and compatibility. The influence of exercise duration on estimated fitness reveals that the model of the phase-oxygen uptake system is not time-invariant related to respiratory metabolism regulation and muscle fatigue. Consequently, it allows us to study the humans’ conversion mechanism at different metabolic rates and facilitates the standardization and development of exercise prescriptions.

关键词： Non-parametric modeling Interval stair training exercise Kernel method.Cardiorespiratory response Oxygen uptake

Hyper spectral resolution stimulated Raman spectroscopy with amplified fs pulse bursts

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Light(Science & Applications) 2024年第3期13卷 566-576页

作者： Hongtao Hu Tobias Flöry Vinzenz Stummer Audrius Pugzlys markus Zeiler Xinhua Xie Aleksei Zheltikov Andrius Baltuška Photonics Institute Technische Universität WienGußhausstraße 27-29Vienna A-1040Austria SwissFEL Paul Scherrer InstituteVilligen PSI 5232Switzerland Institute for Quantum Science and Engineering Department of Physics and AstronomyTexas A&M UniversityCollege StationTX 77843USA

We present a novel approach for Stimulated Raman Scattering(SRS)spectroscopy in which a hyper spectral resolution and high-speed spectral acquisition are achieved by employing amplified offset-phase controlled fs-pulse *** investigate the method by solving the coupled non-linear Schrödinger equations and validate it by numerically characterizing SRS in molecular nitrogen as a model *** spectral resolution of the method is found to be determined by the inverse product of the number of pulses in the burst and the intraburst pulse *** SRS spectrum is obtained through a motion-free scanning of the offset phase that results in a sweep of the Raman-shift *** to high spectral resolution and fast motion-free scanning the technique is beneficial for a number SRS-based applications such as gas sensing and chemical analysis.

关键词： compound spectral resolution

Impact of wastewater treatment plant effluent discharge on the antibiotic resistome in downstream aquatic environments:a mini review

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Frontiers of Environmental Science & Engineering 2024年第3期18卷 131-141页

作者： Zhiguo su Lyujun Chen Donghui Wen School of Environment Tsinghua UniversityBeijng 100084China 2 Zhejiang Provincial Key Laboratory of Water Science and Technology Department of Environmental Technology and EcologyYangtze Delta Region Institute of Tsinghua UniversityJiaxing 314050China College of Environmental Sciences and Engineering Peking UniversityBeijing 100871China

Antimicrobial resistance(AmR)has emerged as a significant challenge in human *** treatment plants(WWTPs),acting as a link between human activities and the environment,create ideal conditions for the selection and spread of antibiotic resistance genes(ARGs)and antibioticresistant bacteria(ARB).Unfortunately,current treatment processes are ineffective in removing ARGs,resulting in the release of large quantities of ARB and ARGs into the aquatic environment through WWTP ***,in turn,leads to their dispersion and potential transmission to human through water and the food *** safeguard human and environmental health,it is crucial to comprehend the mechanisms by which WWTP effluent discharge influences the distribution and diffusion of ARGs in downstream *** this study,we examine the latest researches on the antibiotic resistome in various waterbodies that have been exposed to WWTP effluent,highlighting the key influencing ***,recommendations for future research and management strategies to control the dissemination of ARGs from WWTPs to the environment are provided,with the aim to achieve the“One Health”objective.

关键词： Antibiotic resistance genes(ARGs) Wastewater treatment plants(WWTPs) Effluent-receiving waterbodies Environmental risk Influencing mechanism

Ultra-high-Q free-space coupling to microtoroid resonators

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Light(Science & Applications) 2024年第4期13卷 682-695页

作者： Sartanee suebka Euan mcLeod Judith su Wyant College of Optical Sciences University of ArizonaTucsonAZUSA Department of Biomedical Engineering University of ArizonaTucsonAZUSA

Whispering gallery mode(WGm)microtoroid resonators are one of the most sensitive biochemical sensors in existence,capable of detecting single *** main barrier for translating these devices out of the laboratory is that light is evanescently coupled into these devices though a tapered optical *** hinders translation of these devices as the taper is fragile,suffers from mechanical vibration,and requires precise ***,we eliminate the need for an optical fiber by coupling light into and out from a toroid via free-space coupling and monitoring the scattered resonant light.A single long working distance objective lens combined with a digital micromirror device(DmD)was used for light injection,scattered light collection,and *** obtain Q-factors as high as 1:6´108 with this *** induced transparency(EIT)-like and Fano resonances were observed in a single cavity due to indirect coupling in free *** enables improved sensing *** large effective coupling area(~10μm in diameter for numerical aperture=0.14)removes the need for precise *** performance was verified by combining the system with the frequency locked whispering evanescent resonator(FLOWER)approach to perform temperature sensing experiments.A thermal nonlinear optical effect was examined by tracking the resonance through FLOWER while adjusting the input *** believe that this work will be a foundation for expanding the implementation of WGm microtoroid resonators to real-world applications.

关键词： coupling scattered precise

Re-entry rocket basic flow characteristics and thermal environment of different retro-propulsion modes

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Chinese Journal of Aeronautics 2024年第7期37卷 190-203页

作者： Yifei su Peijie suN Yangwen CUI Guigao LE School of mechanical Engineering Nanjing University of Science and TechnologyNanjing 210094China Shanghai Institute of Aerospace System Engineering Shanghai 200000China Southwest Institute of Technology and Engineering Chongqing 400039China

During the supersonic re-entry of multi-nozzle heavy rockets into the atmosphere,the basic flow state becomes increasingly complex due to the coupling effect between the retropropulsion plumes and the freestream.A numerical method using the hybrid Reynolds-Averaged Navier-Stokes and Large Eddy Simulation(RES)method and discrete coordinate method is developed to accurately estimate the thermal *** addition,finite rate chemical kinetics is used to calculate the afterburning *** numerical results agree well with wind tunnel data,which confirms the validity and accuracy of the numerical *** are conducted for the heavy carrier rocket re-entry from 53.1 km to 39.5 km altitude with 180°angle of attack by using three different supersonic Retro-Propulsion(SRP)*** numerical results reveal that these three SRP flow fields are all Short Penetration models(SPm).As the re-entry altitudes decrease,both the plume-plume interaction and the plume-freestream interaction become *** highest temperatures in the plume shear layers of the three SRP modes increase by 8.36%,7.33%and 6.92%respectively after considering afterburning reactions,and all occur at a reentry altitude of 39.5 *** the rocket re-enters the atmosphere,the maximum heat flux on the rocket base plate of three SRP modes stabilizes at 290,170 and 200 kW/m^(2) respectively,but the maximum heat flux on the side wall increases *** the altitude declines to 39.5 km,the extreme heat flux of the three modes increase by 84.16%,49.45%and 62.97%respectively compared to that at 53.1 km.

关键词： Re-entry rocket multi-nozzle supersonic retro propulsion Thermal environment Afterburning effect

Numerical study of the influence of the atmospheric pressure on the thermal environment in the passenger cabin

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Building Simulation 2024年第2期17卷 253-265页

作者： Xin su Yu Guo Zhengwei Long Yi Cao Tianjin Key Lab.of Indoor Air Environmental Quality Control School of Environmental Science and EngineeringTianjin UniversityTianjin300072China Shanghai Aircraft Design and Research Institute Jinke RoadPudong DistrictShanghai201210China

The cabin air pressure remains lower than the horizontal atmospheric pressure when the airplane is in *** pressure is one of the parameters that must be taken into consideration while studying the thermal environment of an airplane *** are still no reference values for aircraft cabins despite the fact that numerous studies on low pressure heat transfer have demonstrated the connection between convective heat transfer coefficient(CHTC)and air *** this paper,a correction method for CHTC under low pressure conditions was established by using the dummy heat dissipation in the low-pressure cabin *** this basis,a thermal environment simulation model was developed,then was applied to the simulation of a seven-row aircraft cabin containing 42 passengers,and the CHTC and heat loss of dummy surface in the cabin were ***,the results of PmV calculated by using heat dissipation and air parameters at sampling points were *** results show that the modified CHTC can accurately reflect the cabin thermal environment under low pressure conditions,and the correction of CHTC can be realized by adjusting the turbulent Prandtl number,which is nonlinear correlated with the *** simulation results of the thermal environment in the seven-row cabin show that the CHTC changes by about 42%before and after *** air pressure decreases during take-off,which reduces the average CHTC of the crew surface from 5.09 W/(m^(2)·K)to 4.56 W/(m^(2)·K),but the air temperature rises by about 0.2°C as a *** deviation of PmV results calculated by using simulated heat loss data and using air parameters of measuring points in space is up to 0.5,but the latter is representative for calculating the thermal comfort level of the whole cabin.

关键词： low pressure aircraft cabin simulation heat dissipation convective heat transfer coefficient

Fast Blood Oxygenation through Hemocompatible Asymmetric Polymer of Intrinsic microporosity membranes

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Research 2024年第1期2023卷 261-270页

作者： Xinxi Huang Junping Huang Pengcheng su Wanbin Li Guangdong Key Laboratory of Environmental Pollution and Health School of EnvironmentJinan UniversityGuangzhou 511443China

membrane technology has attracted considerable attention for chemical and medical applications,among *** organs play important roles in medical science.A membrane oxygenator,also known as artificial lung,can replenish O_(2) and remove CO_(2) of blood to maintain the metabolism of patients with cardiopulmonary ***,the membrane,a key component,is subjected to inferior gas transport property,leakage propensity,and insufficient *** this study,we report efficient blood oxygenation by using an asymmetric nanoporous membrane that is fabricated using the classic nonsolvent-induced phase separation method for polymer of intrinsic *** intrinsic superhydrophobic nanopores and asymmetric configuration endow the membrane with water impermeability and gas ultrapermeability,up to 3,500 and 1,100 gas permeation units for CO_(2) and O_(2),***,the rational hydrophobic–hydrophilic nature,electronegativity,and smoothness of the surface enable the substantially restricted protein adsorption,platelet adhesion and activation,hemolysis,and thrombosis for the ***,during blood oxygenation,the asymmetric nanoporous membrane shows no thrombus formation and plasma leakage and exhibits fast O_(2) and CO_(2) transport processes with exchange rates of 20 to 60 and 100 to 350 ml m^(−2) min^(−1),respectively,which are 2 to 6 times higher than those of conventional *** concepts reported here offer an alternative route to fabricate high-performance membranes and expand the possibilities of nanoporous materials for membrane-based artificial organs.

关键词： porosity asymmetric Oxygen

Spectral flow, Llarull's rigidity theorem in odd dimensions and its generalization

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Science China mathematics 2024年第5期67卷 1103-1114页

作者： Yihan Li Guangxiang su Xiangsheng Wang Chern Institute of mathematics&LPmC Nankai UniversityTianjin 300071China School of mathematics Shandong UniversityJinan 250100China

For a compact spin Riemannian manifold(m,g^(Tm))of dimension n such that the associated scalar curvature kT m verifies that k^(Tm)≥n(n-1),Llarull’s rigidity theorem says that any area-decreasing smooth map f from m to the unit sphere Sn of nonzero degree is an *** this paper,we present a new proof of Llarull’s rigidity theorem in odd dimensions via a spectral flow *** approach also works for a generalization of Llarull’s theorem when the sphere Sn is replaced by an arbitrary smooth strictly convex closed hypersurface in Rn+*** results answer two questions by Gromov(2023).

关键词： Dirac operator scalar curvature spectral flow