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Assembly structures of coastal woody species of eastern South America:Patterns and drivers

Plant Diversity 2024年第5期46卷 611-620页

作者： eduardo vinícius da Silva Oliveira Myrna Friederichs Landim Sidney F.Gouveia Graduate Program in ecology and Conse.v.tion Federal University of SergipeSão CristovãoSergipeBrazil National institute of Science and Technology ecology Evolution and Conservation of Biodiversity(INCT-EECBio)GoiâniaGoiasBrazil Department of Biology Federal University of SergipeSão CristóvãoSergipeBrazil Department of ecology Federal University of SergipeSão CristóvãoSergipeBrazil

Tropical regions have provided new insights into how ecological communities are *** dry coastal communities,water stress has been hypothesized to determine plant assembly structure by favoring preadapted lineages from neighboring ecosystems,consistent with functional ***,it is unclear whether this hypothesis is sufficient to explain how coastal communities in tropical ecosystems are ***,we test whether water stress or other factors drive community assembly in woody plant communities across the coastal zone of Brazil,a tropical *** characterized functional and phylogenetic structures of these communities and determined the underlying e.v.ronmental factors(e.g.,water stress,historical climate stability,edaphic constraints,and habitat heterogeneity)that drive their community *** of coastal woody species show geographically varied patterns,including stochastic arrangements,clustering,and overdispersion of species relative to their traits and phylogenetic *** complexity,water vapor pressure,and soil nutrient availability best explained the gradient in the functional *** deficit,water vapor pressure,and soil organic carbon were the best predictors of variation in phylogenetic *** results support the water-stress conse.v.tism hypothesis on functional and phylogenetic structure,as well as the effect of habitat heterogeneity on functional structure and edaphic constraints on functional and phylogenetic *** effects are associated with increased phenotypic and phylogenetic divergence of woody plant assemblages,which is likely mediated by abiotic filtering and niche opportunities,suggesting a complex pattern of ecological assembly.

关键词： Brazil Completeness Clustering Restinga vegetation Water constraints

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Ballistic performance of titanium-based layered composites made using blended elemental powder metallurgy and hot isostatic pressing

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Defence Technology（防务技术） 2024年第9期39卷 1-14页

作者： Pavlo Markovsky Jacek Janiszewski Dmytro Savvakin Oleksandr Stasyuk Bartosz Fikus victor Samarov vianey ellison Sergey v.Prikhodko G.v.Kurdyumov institute for Metal Physics of N.A.S.of Ukraine 36Academician Vernadsky BoulevardUA-03142 KyivUkraine Jarosław Dabrowski Military University of Technology 2Gen.Sylwester Kaliski Str.00e908 Warsaw 46Poland Synertech Inc. 11711 Monarch Street Garden GroveLos AngelesCA 92841USA Department of Materials Science and engineering University of California Los AngelesLos AngelesCA 90095USA

Metal matrix composites tiles based on Ti-6Al-4v(Ti64)alloy,reinforced with 10,20,and 40(vol%)of either TiC or TiB particles were made using press-and-sinter blended elemental powder metallurgy(BePM)and then bonded together into 3-layer laminated plates using hot isostatic pressing(HIP).The laminates were ballistically tested and demonstrated superior *** microstructure and properties of the laminates were analyzed to determine the effect of the BePM and HIP processing on the ballistic properties of the layered *** effect of porosity in sintered composites on further diffusion bonding of the plates during HIP is analyzed to understand the bonding features at the interfaces between different adjacent layers in the *** ballistic performance of fabricated structures was explained by a significant reduction in the residual porosity of the BePM products by their additional processing using HIP,which provides an unprecedented increase in the hardness of the layered *** is argued that the combination of the used two technologies,BePM and HIP is principally complimentary for the materials in question with the abilities to solve the essential problems of each used individually.

关键词： Metal matrix composites Powder metallurgy Titanium hydride powder Master alloy Titanium carbide Titanium boride Hot isostatic pressing Ballistic tests

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Probabilistic Analysis and Design of HCP Nanowires:An efficient Surrogate Based Molecular Dynamics Simulation Approach

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Journal of Materials Science & Technology 2016年第12期32卷 1345-1351页

作者： T.Mukhopadhyay A.Mahata S.Dey S.Adhikari College of engineering Swansea UniversitySwanseaUnited Kingdom Department of Materials Science and engineering Missouri University of Science and TechnologyRollaMOUSA Indian institute of Science BangaloreIndia Leibniz-institut fur Polymerforschung Dresden e.v. DresdenGermany

We investigate the dependency of strain rate,temperature and size on yield strength of hexagonal close packed（HCP） nanowires based on large-scale molecular dynamics（MD） simulation.A variance-based analysis has been proposed to quantify relative sensitivity of the three controlling factors on the yield strength of the *** of the major drawbacks of conventional MD simulation based studies is that the simulations are computationally very intensive and economically *** scale molecular dynamics simulation needs supercomputing access and the larger the number of atoms,the longer it takes time and computational *** this reason it becomes practically impossible to perform a robust and comprehensive analysis that requires multiple simulations such as sensitivity analysis,uncertainty quantification and *** propose a novel surrogate based molecular dynamics（SBMD）simulation approach that enables us to carry out thousands of virtual simulations for different combinations of the controlling factors in a computationally efficient way by performing only few MD *** the SBMD simulation approach an efficient optimum design scheme has been developed to predict optimized size of the nanowire to maximize the yield *** the effect of inevitable uncertainty associated with the controlling factors has been quantified using Monte Carlo *** we have confined our analyses in this article for Magnesium nanowires only,the proposed approach can be extended to other materials for computationally intensive nano-scale investigation involving multiple factors of influence.

关键词： hcp-nanowire Yield strength Surrogate Monte Carlo simulation Uncertainty in nanoscale Sensitivity

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Unveiling the atomic-scale transition between light harvesting and photoprotective states in plant photosynthesis

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Science China Chemistry 2024年第5期67卷 1375-1377页

作者： Alexander v.Ruban School of Biological and Behavioural Sciences Queen Mary University of LondonLondon E14NSUK

Non-photochemical chlorophyll fluorescence quenching(NPQ) stands as a cornerstone in the realm of photosynthesis research, attracting generations of dedicated scientists in their quest to unravel its mysteries. This mechanism, crucial for safeguarding photosynthesis, plays a pivotal role in regulating light harvesting, particularly in oxygenic photosynthesis where the oxygen-evolving photosystem II (PSII)is susceptible to photodamage [1].

关键词： harvesting protective attracting

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Palladium-catalyzed enantioselective carbonylation reactions

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Science China Chemistry 2022年第3期65卷 441-461页

作者： Jin-Bao Peng Xin-Lian Liu Lin Li Xiao-Feng Wu School of Biotechnology and Health Sciences Wuyi UniversityJiangmen 529020China Dalian National Laboratory for Clean energy Dalian Institute of Chemical PhysicsChinese Academy of SciencesLiaoning 116023China Leibniz-institut für Katalyse e.v. Albert-Einstein-Straße 29aRostock 18059Germany

Carbonylation,one of the most powerful approaches to the preparation of carbonylated compounds,has rece.v.d significant attention from researchers active in various ***,impressive progress has been made on this subject over the past few *** the.v.rious types of carbonylation reactions,asymmetric carbonylation is a straightforward methodology for constructing chiral *** rhodium-catalyzed enantioselective hydroformylations have been discussed in several elegant reviews,a general review on palladium-catalyzed asymmetric carbonylations is still *** this review,we summarize and discuss recent achievements in palladium-catalyzed asymmetric carbonylation ***,this review’s contents are categorized by reaction type.

关键词： palladium catalyst enantioselective carbonylation chiral

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effects of soil metal(loid)s pollution on microbial activities and e.v.ronmental risks in an abandoned chemical smelting site

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Journal of e.v.ronmental Sciences 2024年第9期143卷 60-70页

作者： Hao Li Jun Yao Jianli Liu Ning Min Geoffrey Sunahara Dongyang Men Robert Duran School of Water Resources and e.v.ronment Research Center of Environmental Science and EngineeringChina University of Geosciences(Beijing)Beijing 100083China Department of Natural Resource Sciences McGill University21111Lakeshore DriveSte-Anne-de-BellevueQuebecH9X 3V9Canada equipe e.v.ronnement et Microbiologie MELODY groupUniversitéde Pau et des Pays de l’AdourE2S-UPPAIPREM UMR CNRS 5254BP 115564013 Pau CedexFrance

Abandoned chemical smelting sites containing toxic substances can seriously threaten and pose a risk to the surrounding ecological *** samples were collected from different depths(0 to 13 m)and analyzed for metal(loid)s content and fractionation,as well as microbial *** potential ecological risk indices for the different soil depths(ordered from high to low)were:1 m(D-1)>surface(S-0)>5 m(D-5)>13 m(D-13)>9 m(D-9),ranging between 1840.65-13,089.62,and representing extremely high e.v.ronmental risks,of which Cd(and probably not arsenic)contributed to the highest e.v.ronmental risk.A modified combined pollution risk index(MCR)combining total content and mobile proportion of metal(loid)s,and relative toxicities,was used to evaluate the degree of contamination and potential e.v.ronmental *** the near-surface samples(S-0 and D-1 layers),the MCR considered that As,Cd,Pb,Sb,and Zn achieved high and alarming degrees of contamination,whereas Fe,Mn,and Ti were negligible or low to moderate pollution *** microcalorimetry and enzymatic activity measurements of contaminated soil samples were used to assess the microbial metabolic activity *** analysis elucidated the relationship between metal(loid)s exchangeable fraction or content and microbial activity characteristics(pe microbial metabolic activity in the D-1 layer was low presumably due to he.v. metal *** activity indicators and microcalorimetric growth rate(k)measurements were considered sensitive indicators to reflect the soil microbial activities in abandoned chemical smelting sites.

关键词： Abandoned chemical smelting sites Microbial activities Modified combined pollution risk Microcalorimetry enzymatic activities

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Antibacterial HA-coatings on bioresorbable Mg alloy

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Journal of Magnesium and Alloys 2024年第5期12卷 1965-1985页

作者： K.v.Nadaraia D.v.Mashtalyar M.A.Piatkova A.I.Pleshkova I.M.Imshinetskiy M.S.Gerasimenko e.A.Belov v.v.Kumeiko D.N.Kozyrev K.A.Fomenko v.v.Mostovaya B.R.Torpanov A.R.Biktimirov I.S.Osmushko S.L.Sinebryukhov S.v.Gnedenkov institute of Chemistry FeB RAS 159 Pr.100-letiya VladivostokaVladivostok 690022Russia Far eastern Federal University 10 Ajax BayRussky IslandVladivostok 690922Russia A.v.Zhirmunsky National Scientific Center of Marine Biology FeB RAS 17 St.PalchevskogoVladivostok 690041Russia Regional Clinical Dermatovenerological Dispensary 18 V St.GamarnikaVladivostok 690033Russia NMIC“Treatment and Rehabilitation Center” 3 Ivankovskoe highwayMoscow 125367Russia

In this study,a calcium-phosphate coating was formed on a Mg-Mn-Ce alloy by the plasma electrolytic oxidation(PeO).The antibiotic vancomycin,widely used in the treatment of infections caused by Staphylococcus aureus(***),was impregnated into the *** with vancomycin showed high bactericidal activity against *** mechanical and electrochemical properties of the formed coatings were studied,as well as in vitro cytotoxicity tests and in vivo tests on mature male rats were *** to SeM,eDS,XRD and XPS data,coatings had a developed morphology and contained hydroxyapatite,which indicates high *** analysis of roughness of coatings without and with vancomycin did not reveal any differences,confirming the high roughness of the *** electrochemical tests,an increase in corrosion resistance by more than two times after the application of PeO coatings was *** to the results of an in vivo study,after 28 days of the implantation of samples with calcium phosphate PeO coating and vancomycin,no signs of inflammation were obse.v.d,while an inflammatory reaction developed in the area of implantation of bare alloy,followed by *** release tests from the coatings show a sharp decrease in the concentration of the released antibiotic on day 7 and then a gradual decrease until day *** the experiment,no significant deviations in the condition and behavior of the animals were obse.v.d;clinical tests did not reveal a systemic toxic reaction.

关键词： Bioactive coatings Biocompatibility Mg alloy Plasma electrolytic oxidation Hydroxyapatite vancomycin

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One-pot and One-step Cu(0)-mediated Reversible-Deactivation Radical Polymerization of N-Isopropylacrylamide(NIPAM) in Water

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Chinese Journal of Polymer Science 2024年第1期42卷 1-6,I0004页

作者： Zi-Shan Li Jing Lyu Bei Qiu Ying-Hao Li Ruth Foley Ri-Jian Song Melissa Johnson Qiang Geng Wen-Xin Wang institute of Precision Medicine(AUST-IPM) Anhui University of Science and TechnologyHuainan 232001China Charles institute of Dermatology School of MedicineUniversity College DublinDublin D04 V1W8Ireland

Copper(0)-mediated reversible-deactivation radical polymerization(Cu(0)-mediated RDRP) of the water-soluble monomer Nisopropylacrylamide(NIPAM) has been challenging with the problems of high dispersity, poor control over the molecular weights(MWs) or complex or multi reaction steps, etc. In this work, we report the well-controlled polymerization of NIPAM in water via a facile one-pot and one-step Cu(0)-mediated RDRP. The results of this approach show that the key for kicking off the Cu(0)-mediated NIPAM RDRPs is to ensure sufficient Cu~I at the.v.ry beginning, and the key to achieve a well-controlled chain growth is to provide adequate deactivation strength during the polymerization process. For NIPAM, which has a high propagation rate constant, the deactivation control can be effectively enhanced by extra adding deactivator(i.e., Cu~II) to the system. More.v.r, a low reaction temperature(4 ℃) is necessary in the controlled synthesis of higher MW poly(Nisopropylacrylamide)(PNIPAM) to avoid the compromise in control caused by the phase transition from its lower critical solution temperature(LCST). Through this new kinetically controlled strategy, PNIPAMs with well-defined structure, narrow molecular weight distributions(MWDs) and varied MWs were successfully achieved.

关键词： Cu(0)-mediated RDRP N-isopropylacrylamide Propagation Deactivation Reaction parameters

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Self-assembled formation of long, thin, and uncoalesced GaN nanowires on crystalline TiN films

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Nano Research 2018年第1期11卷 565-576页

作者： David van Treeck Gabriele Calabrese Jelle J. W. Goertz vladimir M. Kaganer Oliver Brandt Sergio Fernandez-Garrido, Lutz Geelhaar PauI-Drude-lnstitut f~r Festk6rperelektronik Leibniz-lnstitut im Forschungsverbund Berlin e.V. Hausvogteiplatz 5-7 I 0117 Berlin Germany

We investigate in detail the self-assembled nucleation and growth of vertically oriented GaN nanowires by molecular beam epitaxy on crystalline TiN films. We demonstrate that this type of substrate allows for the growth of long and thin GaN nanowires that do not suffer from coalescence, a problem common to the growth on Si and other substrates. Only beyond a certain nanowire length that depends on the nanowire density and exceeds here 1.5 bun, coalescence takes place by bundling, i.e. the same process as on Si. By analyzing the nearest neighbor distance distribution, we identify the diffusion-induced repulsion of neighboring nanowires as the main mechanism limiting nanowire density during nucleation on TiN. Since on Si the final density is determined by shadowing of the impinging molecular beams by existing nanowires, it is the difference in adatom surface diffusion that enables the formation of nanowire ensembles with reduced density on TiN. These nanowire ensembles combine properties that make them a promising basis for the growth of core-shell heterostructures.

关键词： nanocolumn gallium nitride nucleation metal substrate coalescence core-shell

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Copper-Catalyzed Ligand-Controlled Selective Borocarbonylation of α-Substituted Styrenes Toward β-Boryl Aldehydes and Cyclopropyl Boronate esters

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CCS Chemistry 2023年第8期5卷 1866-1875页

作者： Yang Yuan Youcan Zhang Jian-Xing Xu Xiao-Feng Wu Dalian National Laboratory for Clean energy Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian116023 Liaoning Leibniz-institut für Katalyse e.v. Albert-Einstein-Straße 29aRostock 18059

We report a copper-catalyzed ligand-controlled selective carbonylative borofunctionalization ofα-substituted *** reaction provides a general and versatile procedure to synthesize a variety of synthetically usefulβ-boryl quaternary aldehydes and cyclopropyl boronate esters bearing a quaternary carbon *** NHC(IMes=1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene)as the ligand,the carbene intermediate reacts with O-H bond of alcohol while the carbene intermediate would undergo C-H bond insertion when using phosphine ligand[1,2-bis(diphenylphospino)ethane]as the *** of a carbene intermediate has been proposed as the key step for this transformation.

关键词： borocarbonylation copper catalysis carbene insertion ligand-controlled α-substituted styrenes

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