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Aqueous-phase reforming of hydroxyacetone solution to bio-based H_(2)over supported Pt catalysts

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Green Energy & Environment 2024年第4期9卷 777-788页

作者： A.k.k.Vikla k.koichumanova Songbo He k.Seshan Joint International research Laboratory of Circular Carbon Nanjing Tech UniversityNanjing211816China Faculty of Science and Technology University of Twente7500 AE EnschedeThe Netherlands Core Pro 9723 BL GroningenThe Netherlands

Aqueous-phase reforming(APr)is an attractive process to produce bio-based hydrogen from waste biomass streams,during which the catalyst stability is often challenged due to the harsh reaction *** this work,three Pt-based catalysts supported on C,AlO(OH),and ZrO_(2)were investigated for the APr of hydroxyacetone solution in afixed bed reactor at 225℃and 35 *** them,the Pt/C catalyst showed the highest turnover frequency for H_(2)production(TOF of 8.9 molH_(2)molPt^(-1)min^(-1))and the longest catalyst *** the AlO(OH)and ZrO_(2)supported Pt catalysts,the side reactions consuming H_(2),formation of coke,and Pt sintering result in a low H_(2)production and the fast catalyst *** proposed reaction pathways suggest that a promising APr catalyst should reform all oxygenates in the aqueous phase,minimize the hydrogenation of the oxygenates,maximize the WGS reaction,and inhibit the condensation and coking reactions for maximizing the hydrogen yield and a stable catalytic performance.

关键词： APr Hydroxyacetone TOF Bio-based H_(2) Support effect

Influence of Component Size on the Corrosion Behavior of Ti6Al4V Alloy Fabricated by Electron Beam Powder Bed Fusion

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Acta Metallurgica Sinica(English Letters) 2024年第1期37卷 159-168页

作者： Hongyu Zheng Xin Gai Yun Bai Wentao Hou Shujun Li Yulin Hao r.D.k.Misra rui Yang Institute of Metal research Chinese Academy of SciencesShenyang110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang110016China Nuclear Power Institute of China Chengdu610213China Department of Metallurgical Materialsand Biomedical EngineeringThe University of Texas at El Paso500WUniversity AvenueEl PasoTX79968USA

The electrochemical behavior of Ti-6Al-4V with 1 mm and 16 mm thickness prepared by electron beam powder bed fusion(EB-PBF)was investigated in phosphate buffered *** results showed that EB-PBF Ti-6Al-4V with a larger component size was more resistant to corrosion compared to the smaller component,because of less acicularαʹphase content and moreβphase *** a non-equilibrium phase in the“high-energy state”,αʹphase has a greater susceptibility to corrode and reduces the corrosion resistance of the material,whileβphase improves corrosion resistance of titanium *** results show that the phase composition has a more significant effect on the corrosion performance than the grain size.

关键词： Electron beam powder bed fusion Ti6Al4V alloy Corrosion resistance Component size Polarisation

A review of public health guidelines for postpartum physical activity and sedentary behavior from around the world

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Journal of Sport and Health Science 2024年第4期13卷 472-483,F0003页

作者： kelly r.Evenson Wendy J.Brown Alison k.Brinson Emily Budzynski-Seymour Melanie Hayman Department of Epidemiology Gillings School of Global Public HealthUniversity of North Carolina at Chapel HillChapel HillNC 27599-8050USA Faculty of Health Sciences and Medicine Bond UniversityGold CoastQLD 4226Australia School of Human Movement and Nutrition Sciences The University of QueenslandBrisbaneQLD 4072Australia Department of Anthropology University of North Carolina at Chapel HillChapel HillNC 27599-3115USA Carolina Population Center University of North Carolina at Chapel HillChapel HillNC 27599-8120USA Faculty of Sport Health and Social SciencesSolent UniversitySouthamptonSO140YNUK Appleton Institute School of HealthMedical and Applied SciencesCentral Queensland UniversityRockhamptonQLD 4701Australia

Background:The period following pregnancy is a critical time window when future habits with respect to physical activity(PA) and sedentary behavior(SB) are established;therefore,it warrants *** purpose of this scoping review was to summarize public health-oriented country-specific postpartum PA and SB guidelines ***:To identity guidelines published since 2010,we performed a(a) systematic search of 4 databases(CINAHL,Global Health,PubMed,and SPOrTDiscus),(b) structured repeatable web-based search separately for 194 countries,and(c) separate web-based *** the most recent guideline was included for each ***:We identified 22 countries with public health-oriented postpartum guidelines for PA and 11 countries with SB *** continents with guidelines included Europe(n=12),Asia(n=5),Oceania(n=2),Africa(n=1),North America(n=1),and South America(n=1).The most common benefits recorded for PA included weight control/management(n=10),reducing the risk of postpartum depression or depressive symptoms(n=9),and improving mood/well-being(n=8).Postpartum guidelines specified exercises to engage in,including pelvic floor exercises(n=17);muscle strengthening,weight training,or resistance exercises(n=13);aerobics/general aerobic activity(n=13);walking(n=11);cycling(n=9);and swimming(n=9).Eleven guidelines remarked on the interaction between PA and breastfeeding;several guidelines stated that PA did not impact breast milk quantity(n=7),breast milk quality(n=6),or infant growth(n=3).For SB,suggestions included limiting long-term sitting and interrupting sitting with ***:Country-specific postpartum guidelines for PA and SB can help promote healthy behaviors using a culturally appropriate context while providing specific guidance to public health practitioners.

关键词： Breastfeeding Caesarean section Guidelines Postnatal recommendations

Steric Control over Interligand Dihedrals and Splay Leads to the Formation of Fe^(II)_(6)L_(6)and Fe^(II)_(8)L_(8)Antiprisms

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CCS Chemistry 2024年第10期6卷 2411-2419页

作者： Yuchong Yang Yuyin Du Tanya k.ronson Jonathan r.Nitschke Yusuf Hamied Department of Chemistry University of CambridgeCambridge CB21EW

Macrocycles have found uses in guest capture,sensing,and porous materials,motivating the development of new methods for their *** we report the construction of two types of barrelshaped macrocyclic assemblies,with trigonal antiprismatic Fe^(II)_(6)L_(6)and square antiprismatic Fe^(II)_(8)L_(8)architectures,from FeII and boron-containing tritopic *** factors,the steric hindrance of ligands and the preferred coordination angles at different vertices,were observed to regulate the dihedral angles between adjacent ligands,leading to the formation of the structures *** effects of ligand steric hindrance led to the formation of a Fe^(II)_(6)L_(6)trigonal antiprism,which efficiently encapsulated persistent environmental pollutant perfluorosulfonate *** contrast with the iminopyridine chelating groups of the Fe^(II)_(6)L_(6)structure,the incorporation of azopyridine moieties coordinated with the FeII centers not only increased the vertex opening angle,resulting in the construction of a Fe^(II)_(8)L_(8)square antiprism,but also enabled the redox-driven reversible disassembly of this *** design strategies that have enabled the construction of these antiprismatic macrocycles may provide insight into the design principles governing the formation of more complex functional assemblies.

关键词： self-assembly metal-organic cages host-guest chemistry redox-responsive materials dihedral control

First-principles calculations to investigate structural,electronic,magnetic,optical and thermodynamic properties of rE_(2)rh_(3)Ge(rE=Pr,Sm)

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Journal of rare Earths 2024年第7期42卷 1385-1393,I0007页

作者： A.Ezaier r.Masrour M.Hamedoun J.kharbach A.rezzouk A.Hourmatallah N.Benzakour k.Bouslykhane Laboratory of Solid Physics Faculty of Sciences Dhar El MehrazSidi Mohamed Ben Abdellah UniversityBP 1796FezMorocco Equipe de Physique du Solide LaboratoiresLIPIEcole Normale SupérieureBensoudaFèsMorocco

In this paper,we analyzed the physical characteristics of the ternary alloys rE_(2)rh_(3)Ge(rE=Pr and Sm)using the first principles calculation based on functional density theory integrated in the Wien2k *** calculated formation energies of Pr_(2)rh_(3)Ge and Sm_(2)rh_(3)Ge are−5.3827 and−5.2782 eV/atom,respectively,showing that these alloys may exist *** results of the band structure and density of states indicate that all of the compounds tested are magnetic metals,and their magnetism is mostly related to the contribution of Pr and Sm *** total magnetic moments of Pr_(2)rh_(3)Ge and Sm_(2)rh_(3)Ge are 4.07245 and 11.16161μB/f.u,*** parameters such as heat capacity at constant pressure,entropy,Debye temperature,lattice volume,compressibility coefficients,and Grüneisen parameter alloys were calculated using the Gibbs algorithm and studied in depth over a large temperature range of 0-900 *** Debye temperature increases with increasing pressure and decreases with decreasing ***,the Debye temperatures calculated at p=0 GPa and T=300 k are equal to be 342 and 322 k for Pr_(2)rh_(3)Ge and Sm_(2)rh_(3)Ge,*** optical characteristics such as the real and imaginary portions of the dielectric function,the absorption coefficient,the energy-loss function,and the refractive index were investigated and discussed in more depth.

关键词： Magnetic metals Functional density theory Density of states Magnetic moment Optical and thermodynamic properties rare earths

Enhanced termination of zinc and cadmium ions from wastewater employing plain and chitosan-modified mxenes: synthesis, characterization,and adsorption performance

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Green Chemical Engineering 2024年第3期5卷 339-347页

作者： Njood r.Azeez Suhaib S.Salih Mohammed kadhom Harith N.Mohammed Tushar k.Ghosh Department of Chemical Engineering College of Engineering University of Tikrit Department of Environmental Science College of Energy and Environmental Science Al-Karkh University of Science Department of Nuclear Science & Engineering Institute University of Missouri-Columbia

Zinc and cadmium pollutants cause a significant environmental effect that cannot be ignored. Due to their considerable amount in an aqueous environment, industries are seeking suitable adsorbents that are environmentally friendly and inexpensive for removing metals from wastewater before disposing of them in surface waters. This research employed original MXene(MX) and chitosan-modified MXene(CSMX) to extract zinc(Zn(Ⅱ)) and cadmium(Cd(Ⅱ)) metal ions from water-based solutions. The composite material produced was analyzed using techniques such as X-ray Diffraction(XrD), Scanning Electron Microscopy(SEM), Fourier Transform Infrared Spectroscopy(FTIr), and Brunauer-Emmett-Teller(BET). The effects of contact duration, p H of the solution, and initial concentration of metal ions on the adsorption process of Zn(Ⅱ) and Cd(Ⅱ) onto both MX and CSMX composites were investigated. MX and prepared CSMX composite presented a high adsorption capacity for both studied heavy metals, which were 91.55 and 73.82 mg/g for Zn(Ⅱ) and Cd(Ⅱ) onto MX, 106.84 and 93.07 mg/g for Cd(Ⅱ) and Zn(Ⅱ) onto CSMX composite, respectively. Furthermore, the maximum competitive adsorption capacities for Zn(Ⅱ) onto MX and CSMX composites are 77.29 and 93.47 mg/g, and for are Cd(Ⅱ)60.30 and 79.66 mg/g, respectively. Hence, the removal capacities for both single and competitive metal ions were superior to CSMX composite. However, the adsorption capacities after five successive regeneration sequences were only dropped by 13.2% for Zn(Ⅱ) and 17.4% for Cd(Ⅱ) onto the CSMX composite compared to the first cycle. These results confirm that both metals could be efficiently terminated from wastewater, which makes the prepared CSMX composite a favorable candidate adsorbent in practical applications.

关键词： Adsorption Chitosan MXene Zn(II) Cd(II) Wastewater

Nonlinear Coupling of kinetic Alfvén Waves and Ion Acoustic Waves in the Inner Heliosphere

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research in Astronomy and Astrophysics 2024年第10期24卷 141-158页

作者： Mani k.Chettri Vivek Shrivastav rupak Mukherjee Nidhi Gaur r.P.Sharma Hemam D.Singh Department of Physics Sikkim UniversityGangtokSikkimIndia DAV Public School Sector 14GurugramHaryanaIndia Plasma Simulation Laboratory Department of Energy Science and EngineeringIndian Institute of Technology DelhiDelhiIndia

We study the nonlinear coupling of kinetic Alfvén waves with ion acoustic waves applicable to the Earth’s radiation belt and near-Sun streamer belt solar wind using dynamical equations in the form of modified Zakharov *** simulations show the formation of magnetic field filamentary structures associated with density humps and dips which become turbulent at later times,redistributing the energy to higher *** magnetic power spectra exhibit an inertial range kolmogorov-like spectral index value of-5/3 for k_(⊥)ρ_(i)r dissipation range spectra with indices~-3 for the radiation belt case and~-4 for the nearSun streamer belt solar wind case,here k_(⊥)andρ_(i)represent the wavevector component perpendicular to the background magnetic field and the ion thermal gyroradius,*** quasilinear theory in terms of the Fokker-Planck equation in the region of wavenumber turbulent spectra,we find the particle distribution function flattening in the superthermal tail population which is the signature of particle energization and plasma heating.

关键词： Sun:chromosphere Sun:corona Sun:heliosphere

Differential roles of seed and sprout regeneration in forest diversity and productivity after disturbance

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Forest Ecosystems 2024年第3期11卷 371-380页

作者： Marek Mejstrík Martin Svatek Martina Pollastrini Martin Sramek radim Matula Department of Forest Ecology Faculty of Forestry and Wood SciencesCzech University of Life Sciences PragueKamýcka 12916500PragueCzech Republic Department of Forest Botany Dendrology and GeobiocoenologyFaculty of Forestry and Wood TechnologyMendel University in BrnoZemedelska 361300BrnoCzech Republic Department of Agriculture FoodEnvironment and ForestryUniversity of FirenzePiazzale Delle Cascine 2850144FirenzeItaly

Natural regeneration after disturbances is a key phase of forest development,which determines the trajectory of successional changes in tree species composition and *** trees can originate from either seeds or sprouts produced by disturbed trees with sprouting *** both regeneration strategies often develop and co-occur after a disturbance,they tend to affect forest development differently due to significant functional ***,the origin of tree regeneration is rarely distinguished in post-disturbance forest surveys and ecological studies,and the differential roles of seed and sprout regeneration in forest productivity and diversity remain poorly *** address these research gaps,we explored the role of sprout and seed regeneration in the formation of woody species diversity and above-ground biomass(AGB)productivity in early-stage forest *** were collected in two experimental forest stands in the Czech republic,where trees were cut with varying intensities with the density of residual(uncut)trees ranging from 0 to 275 trees per *** trees were mapped and their sizes were measured before cutting and then,either as a stump with sprouts or a residual tree,remeasured 11 years *** addition,all tree saplings were mapped and measured 11 years after logging,and their origin(sprout or seed)was *** assess abundances and productivity,we estimated AGB of all2,685 sprouting stumps of 19 woody species and 504 generative(i.e.,seed origin)individuals of 16 woody species,using allometric ***-effects models were used to analyze the effects of each regeneration strategy on woody species diversity and the total AGB under varying densities of residual *** multidimensional scaling was used to evaluate the effect of regeneration strategies on species *** and diversity of sprouts were significantly higher than those of seed *** formed on average97.1%of

关键词： resprouting Seeding residual trees Tree diversity Above-ground biomass

Influence of erbium on structural,and charged particles,photons,and neutrons shielding properties of Ba_(1-x)Er_(x)SnO_(3) perovskite ceramics

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Journal of rare Earths 2024年第4期42卷 724-732页

作者： M.k.h.Hamad Nidal Dwaikat M.H.A.Mhareb M.I.Sayyed r.M.Hamad Y.S.M.Alajerami M.A.Almessiere Gameel Saleh Ahmad Hussein Alomari k.A.Ziq Department of Basic Sciences School of Social and Basics SciencesAl Hussein Technical UniversityKing Abdullah II St 242Amman11831Jordan Department of Physics College of Engineering and PhysicsInterdisciplinary Research Center for Advanced MaterialsKing Fahd University of Petroleum&MineralsDhahran31261Saudi Arabia Department of Physics College of ScienceImam Abdulrahman Bin Faisal UniversityP.O.Box 1982Dammam31441Saudi Arabia Basic and Applied Scientific research Center Imam Abdulrahman Bin Faisal UniversityP0.Box 1982Dammam31441Saudi Arabia Department of Physics Faculty of ScienceIsra UniversityAmman11622Jordan Department of Nuclear Medicine research Institute for Research and Medical Consultations(IRMC)Imam Abdulrahman Bin Faisal UniversityPo.Box 1982Dammam31441Saudi Arabia Medical Imaging Department Applied Medical Sciences FacultyAl Azhar University-Gaza CityPo.Box 1277Palestine Department of Biophysics Institute for Research and Medical Consultations(IRMC)Imam Abdulrahman Bin Faisal UniversityPo.Box1982Dammam 31441Saudi Arabia Department of Biomedical Engineering College of EngineeringImam Abdulrahman Bin Faisal UniversityPo.Box 1982Dammam31441Saudi Energy&Minerals regulatory Commission Amman11821Jordan

Five perovskite ceramics samples of Ba_(1-x)Er_(x)SnO_(3) with x=0.00,0.05,0.10,0.15,and 0.20 were synthesized using the conventional solid-state reaction *** prepared samples were characterized by X-ray diffraction(XrD),Fourier transforms infrared(FTIr),and UV-Vis *** shielding properties against ionizing radiation were also *** XrD analysis shows the perovskite cubic structure as the major phase in all *** FTIr reveals a distinctive band around 614-620 cm^(-1) ascribed to the antisymmetric O-Sn-O ***-Vis spectroscopy was used to determine the bandgap according to diffuse reflectance,and the results display a fixed enhancement in the bandgap from 3.2 to 3.3 eV for all ***-ray shielding properties of the synthesized samples were experimentally measured and compared with XCOM computational *** relative differences(Δ,%)between experimental and theo retical values are low and fall within the 0.446%-7.10%*** addition of Er leads to the enhanced density,neutron,and gamma shielding *** contrast,charged particles’shielding parameters gradually reduce with rising Er *** results suggest that Ba_(1-x)Er_(x)SnO_(3) samples can be used in different radiation shielding applications.

关键词： Perovskite Ceramics Gamma ray shielding Mass stopping power rare earths