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Color and Gloss Changes of a Lignin-Based Polyurethane Coating under Accelerated Weathering

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Journal of Renewable Materials 2024年第2期12卷 305-323页

作者： Fatemeh Hassani Khorshidi Saeed Kazemi Najafi Farhood Najafi Antonio Pizzi dick Sandberg Rabi Behrooz Department of Wood Science and Technology Faculty of Natural ResourcesTarbiat Modares UniversityTehranIran Department of Resin and Additives Institute for Color Science and TechnologyP.O.Box 16765-654TehranIran LERMAB University of LorraineBlvd des AiguillettesNancy54000France Wood Science and Engineering LuleåUniversity of TechnologySkellefteåSweden

The purpose of this research study was to investigate the properties of polyurethane coatings based on lignin *** this purpose,the prepared coatings were applied to pine wood surfaces and weathered ***,color and gloss of the coatings were measured before and after the weathering *** emission scanning electron microscopy(FE-SEM)micrographs prepared from the coatings showed that the average size of nano-particles in the polyurethane substrate was approximately 500 *** magnetic resonance(13C-NMR)spectroscopy showed that strong urethane bonds were formed in the nano-lignin-based *** calorimetric analysis(DSC)test revealed that the glass-transition temperature(Tg)of lignin nanoparticles modified with diethylenetriamine(DETA)was 112.8℃ and Tg of lignin nano-particles modified with ethylenediamine(EDA)was 102.5℃,which is lower than the Tg of un-modified lignin(114.6℃)and lignin modified with DETA(126.8℃)and lignin modified with EDA(131.3℃).The coatings modified with lignin nano-particles had a greater change in *** lignin nano-particles in the modified coating are trapping hydroxyl radicals which reduces photoactivity and yellowing of the polyurethane by about 3 times compared to unmodified polyurethane *** weathering test,the nano-lignin-based coating had a rougher surface with a lower contact angle(0.78°)compared to the unmodified polyurethane coating(0.85°).

关键词： Amination propylene carbonate lignin biopolymer polyurethane coating polyol UN SDG 13

Low-temperature catalytic methane deep oxidation over sol-gel derived mesoporous hausmannite (Mn_(3)O_(4)) spherical particles

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ChemPhysMater

ChemPhysMater 2024年第3期3卷 329-340页

作者： Patrick Ndouka Ndouka Stephane Kenmoe Jacques Richard Mache Elie Acayanka dick Hartmann Douma Ralph Gebauer Patrick Mountapmbeme Kouotou Department of Chemistry Faculty of SciencesUniversity of MarouaP.O.Box 814 MarouaCameroon Department of Theoretical Chemistry University of Duisburg-EssenD-45141 EssenGermany Department of Mining Engineering School of Geology and Mining EngineeringUniversity of NgaoundéréP.O.Box 115 MeigangaCameroon Department of Inorganic Chemistry Faculty of ScienceUniversity of YaoundéIP.O.Box 812 YaoundéCameroon Groupe de Simulations Numériques en Magnétisme et Catalyse Facultédes Sciences et TechniquesUniversitéMarien NgouabiB.P.69 BrazzavilleCongo The Abdus Salam International Centre for Theoretical Physics(ICTP) 34151 TriesteItaly National Advanced School of Engineering of Maroua University of MarouaP.O.Box 46 MarouaCameroon Higher Institute of Agriculture WoodWater and EnvironmentUniversity of EbolowaP.O.Box 118 EbolowaCameroon

In this study,Mn_(3)O_(4) spherical particles(SPs)were synthesized by the sol-gel process,after which they were thermally annealed at 400℃,and comprehensively characterized.X-ray Diffraction(XRD)revealed that Mn_(3)O_(4) exhibited a tetragonal spinel structure,and Fourier transformed infrared(FTIR)spectroscopy identified surfaceadsorbed functional *** electron microscopy(SEM)and the specific surface area analyses by Brunauer−Emmett−Teller(BET)revealed a porous,homogeneous surface composed of strongly agglomerated spherical grains with an estimated average particle size of∼35 nm,which corresponded to a large specific surface area of∼81.5 m^(2)/g.X-ray photoelectron spectroscopy(XPS)analysis indicated that Mn_(3)O_(4) was composed of metallic cations(Mn^(4+),Mn_(3)+,and Mn^(2+))and oxygen species(O_(2)−,OH−and CO_(3)2−).The optical bandgap energy is∼2.55 *** of the catalytic performance of the Mn_(3)O_(4) SPs indicated T90 conversion of CH4 to CO_(2) and H2O at 398℃ for gas hourly space velocity(GHSV)of 72000 mL^(3) g^(−1) h^(−1).This observed performance can be attributed to the cooperative effects of the smallest spherical grain size with a mesoporous structure,which is responsible for the larger specific surface area and available surface-active oxygenated *** cooperative effect of the good reducibility,higher ratio of active species(OLat/OAds),and results of density functional theory(DFT)calculations suggested that the total oxidation of CH4 over the mesoporous Mn_(3)O_(4) SPs might take place via a two-term process in which both the Langmuir−Hinshelwood and Mars−van Krevelen mechanisms are cooperatively involved.

关键词： Sol-gel Manganese oxide Catalytic oxidation Methane Langmuir−Hinshelwood mechanism Mars−van Krevelen route Two−term process

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面向城市交通噪声控制的树种筛选与种植策略

应用声学 2024年第4期43卷 843-853页

作者：李朦朦 Timothy Van Renterghem 孟琪 dick Botteldooren 康健哈尔滨工业大学建筑与设计学院寒地城乡人居环境科学与技术工业和信息化部重点实验室哈尔滨150001 比利时根特大学工程与建筑学院信息技术系Waves研究组根特9052 英国伦敦大学学院环境设计与工程学院伦敦WC1H 0NN

植物降噪是一种减碳且低成本的降噪方式,可有效改善城市声环境。然而现存植物降噪影响因素与预测模型主要集中在植物群落层面,忽略了树种间差异在不同频率噪声控制过程中的重要作用,难以满足城市交通噪声有效防控的需求。基于此,该研究... 详细信息

植物降噪是一种减碳且低成本的降噪方式,可有效改善城市声环境。然而现存植物降噪影响因素与预测模型主要集中在植物群落层面,忽略了树种间差异在不同频率噪声控制过程中的重要作用,难以满足城市交通噪声有效防控的需求。基于此,该研究以植物树干为切入点,提出一种量化树干与树皮粗糙度的方法,针对交通噪声频谱特征系统测量13种树种的吸收作用,并模拟降噪效果。研究首先测得树干吸声系数的频谱特征,确定了树干主要吸声频率范围与交通噪声频率分布具备较好的一致性;其次,从树种视角分析视觉因素与测试获取因素两个层面对树干吸声效果有影响的主要因素;最后,通过模拟对比分析15 m宽植物带种植不同树种的降噪效果,发现相差∼0.9 dBA,证明了种植吸声系数高的树种对交通噪声控制的有效性。以期从树形、树干吸声效果、树种生长速度以及种植方式等方面,提出应对城市交通噪声污染的树种筛选依据与设计策略。

关键词：噪声控制交通噪声吸声系数自然降噪途径

Spatially-Structured Sharing Technique for Multimodal Problems

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Journal of Computer Science & Technology 2008年第1期23卷 64-76页

作者： Grant dick Peter Whigham Department of Information Science University of OtagoDunedin

Spatially-structured populations are one approach to increasing genetic diversity in an evolutionary algorithm （EA）. However, they are susceptible to convergence to a single peak in a multimodal fitness landscape. Niching methods, such as fitness sharing, allow an EA to maintain multiple solutions in a single population, however they have rarely been used in conjunction with spatially-structured populations. This paper introduces local sharing, a method that applies sharing to the overlapping demes of a spatially-structured population. The combination of these two methods succeeds in maintaining multiple solutions in problems that have previously proved difficult for sharing alone （and vice-versa）.

关键词： evolutionary algorithm multimodal problem domain sharing spatially-structured population

Remediation of saline–sodic soil with flue gas desulfurization gypsum in a reclaimed tidal flat of southeast China

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Journal of Environmental Sciences 2016年第7期28卷 224-232页

作者： Yumei Mao Xiaping Li Warren A.dick Liming Chen East China Normal University Shanghai 200062China The Ohio State University The Ohio Agricultural Research and Development CenterWoosterOH 44691USA

Salinization and sodicity are obstacles for vegetation reconstruction of coastal tidal flat soils. A study was conducted with flue gas desulfurization（FGD）-gypsum applied at rates of 0, 15, 30, 45 and 60 Mg/ha to remediate tidal flat soils of the Yangtze River *** sodium percentage（ESP）, exchangeable sodium（ExNa）, p H, soluble salt concentration, and composition of soluble salts were measured in 10 cm increments from the surface to 30 cm depth after 6 and 18 months. The results indicated that the effect of FGD-gypsum is greatest in the 0–10 cm mixing soil layer and 60 Mg/ha was the optimal rate that can reduce the ESP to below 6% and decrease soil p H to neutral（7.0）. The improvement effect was reached after 6 months, and remained after 18 months. The composition of soluble salts was transformed from sodic salt ions mainly containing Na~＋, HCO_3^-＋ CO_3^（2-）and Cl-to neutral salt ions mainly containing Ca^（2＋）and SO_4^（2-）. Non-halophyte plants were survived at 90%. The study demonstrates that the use of FGD-gypsum for remediating tidal flat soils is promising.

关键词： FGD-gypsum Saline–sodic soil Tidal flat ESP Composition of soluble salt

Transition Modelling with the k-Ω Turbulence Model and an Intermittency Transport Equation

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Journal of Thermal Science 2004年第3期13卷 220-225页

作者： Koen LODEFIER Bart MERCI Chris De LANGHE Erik dick Ghent University Dept. of Flow Heat and Combustion Mechanics Sint-Pietersnieuwstraat 41 B-9000 Gent BelgiumGhent University Dept. of Flow Heat and Combustion Mechanics Sint-Pietersnieuwstraat 41 B-9000 Gent BelgiumGhent University Dept. of Flow Heat and Combustion Mechanics Sint-Pietersnieuwstraat 41 B-9000 Gent BelgiumGhent University Dept. of Flow Heat and Combustion Mechanics Sint-Pietersnieuwstraat 41 B-9000 Gent Belgium

In gas turbine engines, laminar-turbulent transition occurs. However, generally, the turbulence models to describe such transition results in too early and too short transition. Combining a turbulence model with a description of intermittency, i.e. the fraction of time the flow is turbulent during the transition phase, can improve it. By letting grow the intermittency from zero to unity, start and evolution of transition can be imposed. In this paper, a method where a dynamic equation of intermittency combining with a two-equation k-ωturbulence model is described. This intermittency factor is a premultiplicator of the turbulent viscosity computed by the turbulence model. Following a suggestion by Menter et al.[1], the start of transition is computed based on local variables.

关键词： bypass transition intermittency SST turbulence model.

Activation of the Brain to Postpone Dementia: A Concept Originating from Postmortem Human Brain Studies

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Neuroscience Bulletin 2019年第2期35卷 253-266页

作者： Qiong-Bin Zhu Ai-Min Bao dick Swaab Department of Neurology Sir Run Run Shaw HospitalZhejiang University School of Medicine Department of Neurobiology Key Laboratory of Medical Neurobiology of the Ministry of Health of China Zhejiang Province Key Laboratory of Neurobiology Zhejiang University School of Medicine Netherlands Institute for Neuroscience Institute of the Royal Netherlands Academy of Arts and Sciences

Alzheimer's disease(AD) is characterized by decreased neuronal activity and atrophy, while hyperactivity of neurons seems to make them resistant to aging and neurodegeneration, a phenomenon which we have paraphrased as ‘use it or lose it'. Our hypothesis proposes that(1) during their functioning, neurons are damaged;(2)accumulation of damage that is not repaired is the basis of aging;(3) the vulnerability to AD is determined by the genetic background and the balance between the amount of damage and the efficiency of repair, and(4) by stimulating the brain, repair mechanisms are stimulated and cognitive reserve is increased, resulting in a decreased rate of aging and risk for AD. Environmental stimulating factors such as bilingualism/multilingualism, education, occupation, musical experience, physical exercise, and leisure activities have been reported to reduce the risk of dementia and decrease the rate of cognitive decline, although methodological problems are present.

关键词： Dementia Genes Environmental stimulation Brain activation Cognitive reserve Use it or lose it

Application of a k-ε Model to Heat Transfer in Impinging Flows

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Journal of Thermal Science 2004年第1期13卷 62-66页

作者： Bart Merci Chris De Langhe Koen Lodefier Erik dick Ghent University Dept.of FlowHeat and Combustion MechanicsSint-Pietersnieuwstraat 41B-9000 GentBelgiumGhent UniversityDept.of FlowHeat and Combustion MechanicsSint-Pietersnieuwstraat 41B-9000 GentBelgiumGhent UniversityDept.of FlowHeat and Combustion MechanicsSint-Pietersnieuwstraat 41B-9000 GentBelgiumGhent UniversityDept.of FlowHeat and Combustion MechanicsSint-Pietersnieuwstraat 41B-9000 GentBelgium

Local heat transfer is predicted in turbulent axisymmetric jets, impinging onto a flat plate. A non-linear k-e model is used, in which both the constitutive law for the turbulent stresses and the transport equation for the turbulent dissipation rate e have an important contribution in the improved heat transfer predictions. The shape of the Nusselt number profiles, expressing dimensionless heat transfer, as well as the stagnation point value, are well predicted for different distances between the nozzle exit and the plate. Accurate flow field predictions are the basis for good heat transfer predictions. For a fixed Reynolds number, the influence of the nozzle-plate distance is well captured. For a fixed distance, the influence of the Reynolds number is correctly reproduced. Comparisons are made to a low-Reynolds standard k-e model and the v2-f model. A thorough discussion is found in [4]. Only a summary of those results is discussed here, while some new results are also presented.

关键词： local heat transfer impinging jets non-linear k-ε model.

SeaDataNet-Pan-European infrastructure for marine and ocean data management:unified access to distributed data sets

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International Journal of Digital Earth 2010年第S01期3卷 50-69页

作者： dick M.A.Schaap Roy K.Lowry MARIS BV VoorburgThe Netherlands BODC LiverpoolUK

Data availability is of vital importance for marine and oceanographic research but most of the European data are fragmented,not always validated and not easily *** the countries bordering the European seas,more than 1000 scientific laboratories from governmental organisations and private industry collect data using various sensors on board of research vessels,submarines,fixed and drifting platforms,aeroplanes and satellites to measure physical,geophysical,geological,biological and chemical parameters,biological species and *** is an Integrated Research Infrastructure Initiative(I3)(2006-2011)in the EU FP6 framework *** is developing an efficient distributed Pan-European marine data management infrastructure for managing these large and diverse data *** is interconnecting the existing professional data centres of 35 countries,active in data collection and providing integrated databases of standardised quality *** article describes the architecture and the features of the SeaDataNet *** particular it describes the way interoperability is achieved between all the contributing data *** it highlights the on-going developments and challenges.

关键词： ocean data marine data data management infrastructure interoperability