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Friction 2024年第1期12卷 164-173页

作者： Tomáš polÁČEK Petr ŠPERKA Ivan KŘUPKA Faculty of Mechanical Engineering Brno University of TechnologyBrno 61669Czech Republic

Macroscale rolling/sliding conditions are in the superlubricity,a little-studied topic so far.The purpose of this paper is to examine the formation of elastohydrodynamic lubrication(EHL)films by water-based lubricants(glycerol and polyethylene glycol(PEG)),providing superlubricous friction.Experiments were carried out on an optical ball-on-disc tribometer under rolling/sliding conditions.The film thickness was measured by the thin film colorimetric interferometry,and the viscosity of liquids was measured by rotational and high-pressure falling body viscometers.The results show that tribochemical reactions are not the mandatory reason for friction to reach the superlubricity level when using the water-based lubricants.The studied liquids themselves are almost Newtonian.With the addition of water,the signs of shear thinning behavior disappear even more.suitable conditions for this type of lubricant can be predicted using the known Hamrock–Dowson equations.An anomaly in the thickness of the lubricants was observed as an abrupt change at certain conditions.The more PEG there is in the lubricant,the higher the thickness at the beginning of the jump.

关键词： macroscale superlubricity super low traction water-based lubricants elastohydrodynamic lubrication(EHL) film thickness

Burst mode enabled ultrafast laser inscription inside gallium arsenide

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International Journal of Extreme Manufacturing 2022年第4期4卷 179-187页

作者： Andong Wang pol sopeña David Grojo Aix-Marseille University CNRSLP3UMR734113009 MarseilleFrance

Ultrafast laser inscription(ULI)inside semiconductors offers new perspectives for 3D monolithic structures to be fabricated and new functionalities to be added in electronic and photonic microdevices.However,important challenges remain because of nonlinear effects such as strong plasma generation that distort the energy delivery at the focal point when exposing these materials to intense infrared light.Up to now,the successful technological demonstrations have primarily concentrated on silicon(si).In this paper,we target at another important semiconductor:gallium arsenide(GaAs).With nonlinearities higher than those of si,3D-machining of GaAs with femtosecond pulses becomes even harder.However,we show that the difficulty can be circumvented by burst-mode irradiation.We generate and apply trains of pulses at terahertz repetition rates for efficient pulse-to-pulse accumulation of laser-induced free carriers in the focal region,while avoiding an overdose of prefocal excitations.The superior performance of burst-mode irradiation is confirmed by a comparative study conducted with infrared luminescence microscopy.The results indicate a successful reduction of the plasma density in the prefocal region so that higher pulse energy reaches the focal spot.The same method is applied to identify optimum irradiation conditions considering particular cases such as asymmetric pulse trains and aberrated beams.With 64-pulse trains,we successfully manage to cross the writing threshold providing a solution for ULI inside GaAs.The application potential is finally illustrated with a stealth dicing demonstration by taking benefit of the burst mode.The irradiation method opens wide possibilities for 3D structuring inside GaAs by ULI.

关键词： laser processing ultrafast laser inscription THz-repetition-rate burst semiconductors gallium arsenide

structure,magnetic and adsorption properties of novel FePt/h-BN heteromaterials

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Nano Research 2023年第1期16卷 1473-1481页

作者： Anton s.Konopatsky Vladislava V.Kalinina Alena s.savchenko Denis.V.Leybo Ekaterina V.sukhanova Viktor s.Baidyshev Zakhar I.Popov Andrey V.Bondarev Josef polčák Dmitry V.shtansky National University of science and Technology(MIsIs) Leninskiy prospect 4Moscow119049Russia Emanuel Institute of Biochemical Physics RAs Kosygina 4Moscow119334Russia Katanov Khakas state University 90 Lenin pr.655017 AbakanRussia Plekhanov Russian University of Economics 36 Stremyanny per.Moscow 117997Russia Department of Control Engineering Faculty of Electrical EngineeringCzech Technical University in PragueTechnicka 2Prague 16627Czech Republic CEITEC-Central European Institute of Technology Brno University of TechnologyPurkyňova 123Brno 61200 BrnoCzech Republic

Nanomaterials with high specific surface area and high absorption capacity are attracting increased interest aimed at imparting the desired magnetic properties.This work is devoted to the study of the effect of heat treatment in a hydrogen atmosphere on the microstructure,adsorption and magnetic properties of heterogeneous FePt/h-BN nanomaterials.Obtained via the polyol process,FePt nanoparticles(NPs)had a sizestributed over the surface of hexagonal boron nitride(h-BN)nanosheets.The temperature-activated fcc→fct phase transformation in ultrafine FePt NPs has been well documented.FePt NPs act as active centers dissociating H2 molecules and transfer adsorbed hydrogen atoms to the h-BN.Density functional theory(DFT)calculations also indicate that the h-BN substrate can absorb hydrogen adsorbed on the FePt NPs.This hydrogen circulation in the FePt/h-BN system promoted the fcc→fct phase transformation and allowed to control the magnetic properties.FePt/h-BN nanomaterials also exhibited a high adsorption capacity with respect to various organic dyes.

关键词： FePt/h-BN nanomaterials polyol synthesis phase transformations magnetic properties adsorption

Wind energy as a source of green hydrogen production in the UsA

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Clean Energy 2023年第1期7卷 8-22页

作者： Ashish sedai Rabin Dhakal shishir Gautam Bijaya Kumar sedhain Biraj singh Thapa Hanna Moussa suhas pol National Wind Institute Texas Tech UniversityLubbockTX 79401USA Department of Mechanical Engineering Texas Tech UniversityLubbockTX 79401USA Department of Mechanical Engineering Tribhuvan UniversityPurbanchal CampusDharanNepal Green Hydrogen Lab Department of Mechanical EngineeringKathmandu UniversityDhulikhelNepal Wind Energy Program Texas Tech UniversityLubbockTX 79401USA

The study incorporates an overview of the green hydrogen-production potential from wind energy in the UsA,its application in power generation and the scope of substituting grey and blue hydrogen for industrial usage.Over 10 million metric tons of grey and blue hydrogen is produced in the UsA annually to fulfil the industrial demand,whereas,for 1 million metric tons of hydrogen generated,13 million metric tons of CO_(2) are released into the atmosphere.The research aims to provide a state-of-the-art review of the green hydrogen technology value chain and a case study on the production of green hydrogen from an 8-MW wind turbine installed in the southern plain region of Texas.This research estimates that the wind-farm capacity of 130 gigawatt-hours is required to substitute grey and blue hydrogen for fulfilling the current Us annual industrial hydrogen demand of 10 million metric tons.The study investi-gates hydrogen-storage methods and the scope of green hydrogen-based storage facilities for energy produced from a wind turbine.This research focuses on the UsA’s potential to meet all its industrial and other hydrogen application requirements through green hydrogen.

关键词： green hydrogen wind energy electrolysis greenhouse gases

Recent progress in Mg-based alloys as a novel bioabsorbable biomaterials for orthopedic applications

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Journal of Magnesium and Alloys 2022年第6期10卷 1428-1456页

作者： Fei Xing shang Li Dongdi Yin Jichang Xie pol Maria Rommens Zhou Xiang Ming Liu Ulrike Ritz Orthopedic Research Institute Department of OrthopedicsWest China HospitalSichuan UniversityNo.37 Guoxue LaneChengduSichuan 610041China Department of Plastic and Burn surgery West China HospitalSichuan UniversityNo.37 Guoxue LaneChengduSichuan 610041China Key Laboratory of Advanced Technologies of Materials Ministry of EducationSchool of Materials Science and EngineeringSouthwest Jiaotong UniversityChengduSichuan 610031China Laboratoire Roberval FRE UTC-CNRS 2012Sorbonne universitésUniversitéde Technologie de CompiègneCentre de recherche RoyallieuCS60319Compiègne CEDEX 60203France Department of Orthopaedics and Traumatology Biomatics GroupUniversity Medical Center of the Johannes Gutenberg UniversityLangenbeckstr.1Mainz 55131Germany

Traditional orthopedic metal implants,such as titanium(Ti),Ti alloys,and cobalt-chromium(Co-Cr)alloys,cannot be degraded in vivo.Fracture patients is must always suffer a second operation to remove the implants.Moreover,stress shielding,or stress protection occurs when traditional orthopedic metal implants are applied in fractures surgery.The mechanical shunt produced by traditional orthopedic metal implants can cause bone loss over time,resulting in decreased bone strength and delayed fracture healing.Biodegradable metals that‘biocorrode’are currently attracting significant interest in the orthopedics field due to their suitability as temporary implants.As one of the biodegradable metals,magnesium(Mg)and Mg alloys have gained interest in the field of medicine due to their low density,excellent biocompatibility,high bioresorbability,and proper mechanical properties.Additionally,Mg ions released from the metal implants can promote osteogenesis and angiogenesis during the degradation process in vivo,which is substantially better for orthopedic fixation than other bioinert metal materials.Therefore,this review focuses on the properties,fabrication,biological functions,and surface modification of Mg-based alloys as novel bioabsorbable biomaterials for orthopedic applications.

关键词： Magnesium Mg alloys Biomedical implants Bone regeneration surface modification

Metabolomic fingerprinting of pig seminal plasma identifies in vivo fertility biomarkers

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Journal of Animal science and Biotechnology 2022年第2期13卷 473-487页

作者： Yentel Mateo-Otero pol Fernández-López Ariadna Delgado-Bermúdez Pau Nolis Jordi Roca Jordi Miró Isabel Barranco Marc Yeste Biotechnology of Animal and Human Reproduction(Technosperm) Institute of Food and Agricultural TechnologyUniversity of GironaES-17003 GironaSpain Department of Biology Unit of Cell BiologyFaculty of SciencesUniversity of GironaES-17003 GironaSpain Centre d’Estudis Avançats de Blanes(CEAB) Spanish Research Council(CSIC)ES-17300 GironaSpain Magnetic Nuclear Resonance Facility Autonomous University of BarcelonaBellaterraES-08193 Cerdanyola del VallèsSpain Department of Animal Medicine and surgery Faculty of Veterinary MedicineUniversity of MurciaES-30100 MurciaSpain Equine Reproduction service Department of Animal Medicine and SurgeryFaculty of Veterinary MedicineAutonomous University of BarcelonaBellaterraES-08193 Cerdanyola del VallèsSpain Department of Veterinary Medical sciences University of BolognaIT-40064 Ozzano dell’EmiliaBolognaItaly

Background:Metabolomic approaches,which include the study of low molecular weight molecules,are an emerging-omics technology useful for identification of biomarkers.In this field,nuclear magnetic resonance(NMR)spectroscopy has already been used to uncover(in)fertility biomarkers in the seminal plasma(sP)of several mammalian species.However,NMR studies profiling the porcine sP metabolome to uncover in vivo fertility biomarkers are yet to be carried out.Thus,this study aimed to evaluate the putative relationship between sPmetabolites and in vivo fertility outcomes.To this end,24 entire ejaculates(three ejaculates per boar)were collected from artificial insemination(AI)-boars throughout a year(one ejaculate every 4 months).Immediately after collection,ejaculates were centrifuged to obtain sP-samples,which were stored for subsequent metabolomic analysis by NMR spectroscopy.Fertility outcomes from 1525 inseminations were recorded over a year,including farrowing rate,litter size,stillbirths per litter and the duration of pregnancy.Results:A total of 24 metabolites were identified and quantified in all sP-samples.Receiver operating characteristic(ROC)curve analysis showed that lactate levels in sP had discriminative capacity for farrowing rate(area under the curve[AUC]=0.764)while carnitine(AUC=0.847),hypotaurine(AUC=0.819),sn-glycero-3-phosphocholine(AUC=0.833),glutamate(AUC=0.799)and glucose(AUC=0.750)showed it for litter size.similarly,citrate(AUC=0.743),creatine(AUC=0.812),phenylalanine(AUC=0.750),tyrosine(AUC=0.753)and malonate(AUC=0.868)levels had discriminative capacity for stillbirths per litter;and malonate(AUC=0.767)and fumarate(AUC=0.868)levels for gestation length.Conclusions:The assessment of selected sP-metabolites in ejaculates through NMR spectroscopy could be considered as a promising non-invasive tool to predict in vivo fertility outcomes in pigs.Moreover,supplementing AI-doses with specific metabolites should also be envisaged as a way to improve their fertility potential.

关键词： Artificial insemination in vivo fertility Metabolomics NMR Pregnancy outcomes seminal plasma

The effects of transcranial direct current stimulation on gait in patients with Parkinson’s disease:a systematic review

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Translational Neurodegeneration 2021年第2期10卷 275-293页

作者： Fateme pol Mohammad Ali salehinejad Hamzeh Baharlouei Michael A.Nitsche Musculoskeletal Research Center Isfahan University of Medical SciencesIsfahanIran Department of Psychology and Neurosciences Leibniz Research Centre for Working Environment and Human FactorsDortmundGermany Department of Neurology University Medical Hospital BergmannsheilBochumGermany

Background:Gait problems are an important symptom in Parkinson’s disease(PD),a progressive neurodegenerative disease.Transcranial direct current stimulation(tDCs)is a neuromodulatory intervention that can modulate cortical excitability of the gait-related regions.Despite an increasing number of gait-related tDCs studies in PD,the efficacy of this technique for improving gait has not been systematically investigated yet.Here,we aimed to systematically explore the effects of tDCs on gait in PD,based on available experimental studies.Methods:Using the PRIsMA(Preferred Reporting Items for systematic Reviews and Meta-Analyses)approach,PubMed,Web of science,scopus,and PEDro databases were searched for randomized clinical trials assessing the effect of tDCs on gait in patients with PD.Results:Eighteen studies were included in this systematic review.Overall,tDCs targeting the motor cortex and supplementary motor area bilaterally seems to be promising for gait rehabilitation in PD.studies of tDCs targeting the dorosolateral prefrontal cortex or cerebellum showed more heterogeneous results.More studies are needed to systematically compare the efficacy of different tDCs protocols,including protocols applying tDCs alone and/or in combination with conventional gait rehabilitation treatment in PD.Conclusions:tDCs is a promising intervention approach to improving gait in PD.Anodal tDCs over the motor areas has shown a positive effect on gait,but stimulation of other areas is less promising.However,the heterogeneities of methods and results have made it difficult to draw firm conclusions.Therefore,systematic explorations of tDCs protocols are required to optimize the efficacy.

关键词： Transcranial direct current stimulation Gait Parkinson’s disease

聚乙二醇干扰素α-2b联合利巴韦林与标准α-2b干扰素联合利巴韦林对合并HIV感染患者的慢性丙型肝炎的疗效比较:一项随机对照试验

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世界核心医学期刊文摘（胃肠病学分册） 2005年第5期1卷 9-10页

作者： Carrat F. Bani-sadr F. pol s 郝筱倩 Groupe Hospitalier Universitaire Est UniversitéParis 6INSERM U444ParisFrance Dr

Context: Treatment of chronic hepatitis C virus (HCV) infection in human immunodeficiency virus (HIV)-infected patients is a growing concern. Most data on the virologic efficacy and safety of the combination of peginterferon alfa-2b and ribavirin in coinfected patients come from uncontrolled studies. Objective: To study the safety and efficacy of peginterferon alfa-2b plus ribavirin vs standard interferon alfa-2b plus ribavirin in HIV-HCV coinfected patients. Design and settings: A multicenter,randomized,parallel-group,open-label trial. Patients were enrolled from February 2000 to February 2002 and followed up for 72 weeks. Patients: Four hundred twelve HIV-HCV coinfected patients with detectable serum HCV-RNA,abnormal liver histology,a CD4 cell count of at least 200 ×106/L,and stable plasma HIV-RNA. Intervention: Treatment with ribavirin 400 mg twice a day,orally,plus either peginterferon alfa-2b (1.5 μg/kg subcutaneous injection once a week) or standard interferon alfa-2b (3 million units of subcutaneous injection 3 times a week) for 48 weeks. Main Outcome Measures: sustained virologic response,defined by undetectable serum HCV-RNA at week 72. Results: More patients had sustained virologic responses in the peginterferon group than in the standard interferon group (27%vs 20%,P=.047). This difference between the treatments was found in patients with HCV genotype 1 or 4 infection (17%for peginterferon vs 6%for standard interferon,P=.006) but was not found in patients with HCV genotype 2,3,or 5 (44%for peginterferon vs 43%for standard interferon,P=.88). Together,a decline in HCV-RNA of less than 2 log10 from baseline and detectable serum HCV-RNA at week 12 predicted 99%of treatment failures. Histologic activity diminished and fibrosis stabilized in virologic responders. The 2 regimens showed similar tolerability although dose modifications for clinical and biological events were more frequent with peginterferon. Eleven cases of pancreatitis or symptomatic hyperlactatemia were observed,all in patients receiving dida

关键词：慢性丙型肝炎干扰素α HIV感染患者干扰素联合随机对照试验肝脏组织学感染人群合并感染者细胞计数二脱氧腺苷

Induced pluripotent stem cells for modeling and cell therapy of Parkinson＇s disease

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Neural Regeneration Research 2016年第5期11卷 727-728页

作者： Mária Csobonyeiová Lubos Danisovic stefan polák Institute of Histology and Embryology Faculty of Medicine Comenius University in Bratislava Bratislava Slovakia Institute of Medical Biology Genetics and Clinical Genetics Faculty of Medicine Comenius University in Bratislava Bratislava Slovakia

Neurodegenerative disorders include a variety of hereditary or sporadic diseases involving the chronic,progressive loss on neural tissue.Parkinson＇s disease（PD）is the second most common neurodegenerative disease,affecting more than 6 million people worldwide（Wan et al.,2015）.Degeneration of nigrostriatal dopamine（DA）neurons is the main pathology in PD.

关键词： INDUCTION IPsCs

Real drive cycles analysis by ordered power methodology applied to fuel consumption,C0_(2),NO_(x) and PM emissions estimation

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Frontiers of Environmental science & Engineering 2021年第1期15卷 77-90页

作者： pol Masclans Abello Vicente Medina Iglesias M.Antonia de los santos Lopez Jesus Alvarez-Florez Center for Engines and Heat Installation Research(CREMIT-UPC).Universitat politecnica de Catalunya-BarcelonaTech.Av.Diagonal 547(ETsEIB)08028 Barcelona Spain Department of Thermal Machinery of Universitat politecnica de Catalunya-BarcelonaTech and CREMIT-UPC.-BarcelonaTech.Av.Diagonal 547(ETsEIB)08028 Barcelona Spain 3 Department of Mechanical Engineering of Universitat politecnica de Catalunya-BarcelonaTech and CREMIT-UPC.-BarcelonaTech.Av.Diagonal 547(ETsEIB)08028 Barcelona Spain

In this work three fuel consumption and exhaust emission models,ADVIsOR,VT-MICRO and the European Environmental Agency Emission factors,have been used to obtain fuel consumption(FC)and exhaust emissions.These models have been used at micro-scale,using the two signal treatment methods presented.The manuscript presents:1)a methodology to collect data in real urban driving cycles,2)an estimation of FC and tailpipe emissions using some available models in literature,and 3)a novel analysis of the results based on delivered wheel power.The results include Fuel Consumption(FC),CO_(2),NO_(x) and PM_(10) emissions,which are derived from the three simulators.In the first part of the paper we present a new procedure for incomplete drive cycle data treatment,which is necessary for real drive cycle acquisition in high density cities.Then the models are used to obtain second by second FC and exhaust emissions.Finally,a new methodology named Cycle Analysis by Ordered Power(CAbOP)is presented and used to compare the results.This method consists in the re-ordering of time dependant data,considering the wheel mechanical power domain instead of the standard time domain.This new strategy allows the 5 situations in drive cycles to be clearly visualized:hard breaking zone,slowdowns,idle or stop zone,sustained speed zone and acceleration zone.The complete methodology is applied in two real drive cycles surveyed in Barcelona(spain)and the results are compared with a standardized WLTC urban cycle.

关键词： Cycle Analysis by Ordered Power(CAbOP) Micro and macro models Real drive cycle NO_(x)/PM_(10)/CO_(2)emissions Wheel mechanical power domain Worldwide Harmonized Light-Duty Vehicles Test Cycle(WLTC)