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Journal of Thermal Science 2024年第5期33卷 1946-1960页

作者： YU Chunkan YANG Bin Institute of Technical Thermodynamics Karlsruhe Institute of TechnologyKarlsruhe 76131Germany Center for Combustion Energy Tsinghua UniversityBeijing 100084China

In this study,we conduct a thorough evaluation of the STGSA-generated skeletal mechanism for C_(2)H_4/*** STGSA-reduced mechanisms are taken into account,incorporating basic combustion models such as the homogeneous reactor model,one-dimensional flat premixed flame,and non-premixed counterflow ***,these models are applied to more complex combustion systems,considering factors like flame-flow interaction and flame-wall *** considerations take into account additional physical parameters and processes such as mixing frequency and *** results indicate that the skeletal mechanism adeptly captures the behavior of these complex combustion ***,it is suggested to incorporate strain rate considerations in generating the skeletal mechanism,especially when the combustion system operates under high turbulent intensity.

关键词： Species-Targeted Global Sensitivity Analysis(STGSA) mechanism reduction Partially Stirred Reactor(PaSR) spark ignition Head-on Quenching(HoQ)

Editorial for the special issue“Hydrogen Energy Production,Storage and Utilization”

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Materials Reports(Energy) 2024年第1期4卷 1-2页

作者： Lixian Sun Guest Editor Guilin University of Electronic Technology China

Hydrogen energy has emerged as a significant energy source for accomplishing energy transformation and achieving carbon *** production,storage and transportation are the key technologies to realize hydrogen energy application and carbon neutralization *** from the mature technologies of fossil fuel reforming and water electrolysis,new hydrogen production methods(such as solar photolysis,biomass conversion,thermochemical circulation,etc.)have garnered widespread attention and research *** lack of safe and efficient hydrogen storage and utilization technology for hydrogen fuel cell systems is the major obstacle to achieving hydrogen *** the past decades,global researchers have conducted extensive studies on enhancing the hydrogen storage performance of materials,such as alloy,metal hydride,complex hydride,carbon-based materials,etc.,as well as the technological development of fuel cell power generation systems using solid hydrogen storage materials as hydrogen storage *** themed issue entitled“Hydrogen Energy Production,Storage and Utilization”includes 10 carefully selected papers that address the most recent developments in hydrogen production and storage materials,involving catalyst design,structure characterization,hydrogen ab-/desorption performance and mechanism,and fuel cell coupling system exploit.

关键词： alloy Storage hydride

Effects of the urban heat island and climate change on the growth of Khaya senegalensis in Hanoi,Vietnam

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Forest Ecosystems 2018年第4期5卷 516-529页

作者： Astrid Moser-Reischl Enno Uhl Thomas Rotzer Peter Biber Tran van Con Nguyen Thanh Tan Hans Pretzsch Chair for Forest Growth and Yield Science Center of Life and Food Sciences WelhenstephanTechnical University MunichHans-Carl-von-Carlowitz-Platz 285354 FreisingGermany Vietnamese Academy of Forest Sciences Dong Ngac CommuneTu Liem DistrictHanoiVietnam Tay Nguyen University 567 Le Duan StreeBuon Ma Thuot CityDak La ProvinceVietnam

Background: Recent projections expect that Vietnam will be affected most severely by climate change with higher temperatures, more precipitation and rising sea levels. Especially increased temperatures will worsen the situations in cities, amplifying the urban heat island effect. Green infrastructures, i.e. urban trees are a common rtool to improve the urban micro-climate for humans. Vital and well growing trees provide greatest benefits such as evaporative cooling, shading, air filtering and carbon storage. However, urban tree growth is often negatively affected by urban growing conditions such as high soil sealing with compacted tree pits providing small growing spaces with limited water, nutrient and oxygen supply, further warm temperatures and high pollution emissions. This study analyzed the growth of urban and rural African mahogany(Khaya senegalensis(Desr.) A. Juss.) trees in the city of Hanoi, Vietnam and the effects of the surrounding climate conditions on tree ***: The results showed that rural African mahogany trees grew better than trees situated in the city center, which is contrary to other results on tree growth of temperate and subtropical cities worldwide. Moreover tree growth was similar regardless of the time of growth. Other results regarding stem growth of African mahogany located in different areas of Hanoi(east, west, north, city center) revealed a better growth in the northern and western outskirts of the city compared to the growth of trees in the city ***: African mahogany trees in the urban centers of Hanoi showed a decreased growth compared to rural trees,which was likely induced by a low ground-water level and high pollution rates. In view of climate change and global warming, the decreased tree growth in the city center may also affect tree service provision such as shading and cooling. Those climate mitigation solutions are strongly needed in areas severely affected by climate change and global warming such as

关键词： African mahogany Dendrochronology Ecosystem services Urban tree growth

Modelling of Equilibrium Grain Boundary Solute Segregation under Irradiation

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Journal of Materials Science & Technology 2005年第2期21卷 196-200页

作者： ShenhuaSONG R.G.Faulkner P.E.J.Flewitt LuqianWENG DivisionofMaterialsScienceandEngineering ShenzhenGraduateSchoolHarbinInstituteofTechnologyShenzhenUniversityTownXiliShenzhen518055China InstituteofPolymerTechnologyandMaterialsEngineering LoughboroughUniversityLoughboroughLeicestershireLEll3TUUK InterfaceAnalysisCentre UniversityofBristolBristolBS28BSUK

Both radiation-induced excess vacancies and solute-interstitials may enhance solute diffusion. The radiation-enhanced solute diffusion promotes the kinetic process of equilibrium segregation. This effect is especially considerable in the low temperature range. As a complement to modelling of radiation-induced non-equilibrium segregation, the radiation-created vacancy and solute-interstitial-accelerated equilibrium grain boundary solute segregation were theoretically treated. The models were applied to phosphorus segregation in α-Fe subjected to neutron irradiation.

关键词： Radiation Point defects Diffusion Grain boundary Segregation

Mechanochemical spinodal decomposition: a phenomenological theory of phase transformations in multi-component, crystalline solids

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npj Computational Materials 2016年第1期2卷 133-141页

作者： Shiva Rudraraju Anton Van der Ven Krishna Garikipati Department of Mechanical Engineering University of MichiganAnn ArborMIUSA Materials Department University of CaliforniaSanta BarbaraCAUSA Department of Mathematics University of MichiganAnn ArborMIUSA

We present a phenomenological treatment of diffusion-driven martensitic phase transformations in multi-component crystalline solids that arise from non-convex free energies in mechanical and chemical *** treatment describes diffusional phase transformations that are accompanied by symmetry-breaking structural changes of the crystal unit cell and reveals the importance of a mechanochemical spinodal,defined as the region in strain–composition space,where the free-energy density function is *** approach is relevant to phase transformations wherein the structural order parameters can be expressed as linear combinations of strains relative to a high-symmetry reference *** governing equations describing mechanochemical spinodal decomposition are variationally derived from a free-energy density function that accounts for interfacial energy via gradients of the rapidly varying strain and composition fields.A robust computational framework for treating the coupled,higher-order diffusion and nonlinear strain gradient elasticity problems is *** the local strains in an inhomogeneous,transforming microstructure can be finite,the elasticity problem must account for geometric *** evaluation of available experimental phase diagrams and first-principles free energies suggests that mechanochemical spinodal decomposition should occur in metal hydrides such as ZrH_(2−2c).The rich physics that ensues is explored in several numerical examples in two and three dimensions,and the relevance of the mechanism is discussed in the context of important electrode materials for Li-ion batteries and high-temperature ceramics.

关键词： microstructure phase chemical

Smart composite antibacterial coatings with active corrosion protection of magnesium alloys

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Journal of Magnesium and Alloys 2022年第12期10卷 3589-3611页

作者： A.S.Gnedenkov S.L.Sinebryukhov V.S.Filonina N.G.Plekhova S.V.Gnedenkov Institute of Chemistry of FEB RAS 159 Pr.100-letiya VladivostokaVladivostok690022Russia

A new method of the formation of composite coatings with the function of active corrosion protection of magnesium alloys was developed using the plasma electrolytic oxidation(PEO) method. Susceptibility of PEO-layers to pitting formation was evaluated using localized electrochemical methods(SVET/SIET). The morphological features and electrochemical properties of composite coatings were studied using SEM/EDX, XRD, micro-Raman spectroscopy and EIS/PDP measurements, respectively. The effect of surface layers impregnation with corrosion inhibitor on their protective properties in a corrosive environment was established. Additional protection was achieved using controllable coating pore sealing with polymer. It was found that the polymer treatment of the PEO-layer does not reduce the inhibitor’s efficiency. The formed protective composite inhibitor-and-polymer-containing layers decrease the corrosion current density of a magnesium alloy in a 3 wt.% Na Cl solution to three orders of magnitude. This predetermines the prospect of new smart coatings formation that significantly expand the field of application of electrochemically active materials. The mechanism of smart composite coating corrosion degradation was established. The antibacterial activity of the inhibitor-containing coatings against S. aureus methicillin-resistant strain was proved using the in vitro model. These protective layers are promising for reducing the incidence of implant-associated infections.

关键词： Magnesium alloy Plasma electrolytic oxidation Corrosion inhibitor Self-healing Protective coatings

Effects of Climate and the Urban Heat Island Effect on Urban Tree Growth in Houston

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Open Journal of Forestry 2017年第4期7卷 428-445页

作者： Astrid Moser Enno Uhl Thomas Rotzer Peter Biber Jens Dahlhausen Barry Lefer Hans Pretzsch Chair of Forest Growth and Yield Science Center of Life and Food Sciences WeihenstephanTechnical University MunichFreisingGermany NASA Headquarters Earth Science DivisionWashington DCUSA

The growing conditions of urban trees differ substantially from forest sites and are mainly characterized by small planting pits with less water, nutrient and aeration availability, high temperatures and radiation inputs as well as pollution and soil compaction. Especially, global warming can amplify the negative effects of urban microclimates on tree growth, health and well-being of citizens. To quantify the growth of urban trees influenced by the urban climate, ten urban tree species in four climate zones were assessed in an overarching worldwide dendrochronological study. The focus of this analysis was the species water oak (Quercus nigra L.) in Houston, Texas, USA. Similar to the overall growth trend, we found in urban trees, water oaks displayed an accelerated growth during the last decades. Moreover, water oaks in the city center grew better than the water oaks growing in the rural surroundings of Houston, though this trend was reversed with high age. Growth habitat (urban, suburban, rural and forest) significantly affected tree growth (p < 0.001) with urban trees growing faster than rural growing trees and forest trees, though a younger age of urban trees might influence the found growth patterns. Growing site in terms of cardinal direction did not markedly influence tree growth, which was more influenced by the prevalent climatic conditions of Houston and the urban climate. Higher temperatures, an extended growing season and eutrophication can cause an accelerated growth of trees in urban regions across, across all climatic zones. However, an accelerated growth rate can have negative consequences like quicker ageing and tree death resulting in higher costs for new plantings and tree management as well as the decrease in ecosystem services due to a lack of old trees providing greatest benefits for mitigating the negative effects of the urban climate.

关键词： Climate Change Growth Trends Heat Island Effect Quercus nigra Tree Ring Analyses

Gait analysis of patients with knee osteoarthritis before and after Chinese massage treatment

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Journal of Traditional Chinese Medicine 2015年第4期35卷 411-416页

作者： Zhu Qingguang Fang Min Gong Li Jiang Shuyun Sun Wuquan Li Jianhua Li Yong Department of Physical Therapy with Chinese Massage Yueyang Hospital of Integrated Traditional Chinese and Western MedicineShanghai University of Traditional Chinese Medicine Research Institute of Chinese Massage Shanghai Academy of Traditional Chinese Medicine

The objective of this study was to evaluate the effectiveness of Chinese massage therapy in patients with knee osteoarthritis(OA) by measuring lower-limb gait parameters. We recruited 20 women with knee OA,who then underwent Chinese massage therapy three times per week for 2 weeks. The patients underwent gait evaluation using a six-camera infrared motion analysis system. They completed Western Ontario and Mc Master Universities Osteoarthritis Index questionnaires before and after treatment. We calculated the forward speed,step width,step length,total support time percentage,initial double support time percentage,and single support time percentage. We also measured the angles at the knee,hip,and ankle during the stance phase of walking. The results showed statistically significant mean differences in knee pain relief,alleviation of stiffness,and physical function enhancement after therapy(P < 0.05). The patients gained significantly faster gait speed,greater step width,and increased total support time percentage after the Chinese massage therapy(P < 0.05). There were no significant differences in the range of motion or initial contact angles of the knee,hip,or ankle during the stance phase of walking. We concluded that Chinese massage is a beneficial complementary treatment and an alternative therapy choice for patients with knee OA for short-term pain relief. Chinese massage may improve walking ability for these patients.

关键词： Gait Osteoarthritis Knee Massage

Hydroxyapatite-containing PEO-coating design for biodegradable Mg-0.8Ca alloy: Formation and corrosion behaviour

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Journal of Magnesium and Alloys 2023年第12期11卷 4468-4484页

作者： A.S.Gnedenkov S.L.Sinebryukhov V.S.Filonina S.V.Gnedenkov Institute of Chemistry of FEB RAS 159 Pr.100-letiya VladivostokaVladivostok690022Russian Federation

In this study, the biocompatible protective coating was formed using plasma electrolytic oxidation(PEO) on bioresorbable Mg-0.8Ca alloy. The composition of the formed coating was studied using XRD, SEM-EDX analysis, and micro-Raman spectroscopy. The uniform distribution of hydroxyapatite over the thickness of protective PEO-layer was established. Using traditional(EIS, PDP, OCP) and local scanning electrochemical methods(SVET, SIET with H^(+)-selective microelectrode), the level of protective properties of PEO-layer in a biological environment(mammalian cell culture medium, MEM) was determined. It was established that modification of Mg-0.8Ca alloy surface by PEO contributes to a significant increase in the corrosion resistance of the surface layer, making it possible to control the process of material‘s biodegradation. The maximum local electrochemical activity was recorded after 72 h of testing, while for the uncoated sample,intense corrosion degradation was recorded in the first 12 min of exposure to the cell culture medium. Formation of the PEO-coating results in a twofold decrease in the corrosion current density(2.8·10^(-6)A cm^(-2)) and an increase in the impedance modulus measured at a low frequency(1.7·10^(4)Ω cm^(2)) in comparison with the uncoated material(9.5·10^(-6)A cm^(-2);8.1·10^(3)Ω cm^(2)). The mechanism of material bioresorption was established and a model for biodegradation process of Mg-0.8Ca alloy with hydroxyapatite-containing PEO-coating in MEM was proposed. Analysis of these results and comparing with others obtained by various scientific groups indicate the prospects for application of biocompatible PEO-coating on Mg-Ca alloy in implant surgery.

关键词： Magnesium-calcium alloy Biodegradation Implant surgery Plasma electrolytic oxidation Electrochemistry Minimum essential medium Hydroxyapatite