检索结果-南通市图书馆

Drought events influence nutrient canopy exchanges and green leaf partitioning during senescence in a deciduous forest

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Forest Ecosystems 2024年第1期11卷 110-119页

作者： J.Touche c.calvaruso p.De Donato m.-p.Turpault INrAE BEFF-54000NancyFrance Umr 7359 GeoRessourcesFaculte des Sciences-Campus des Aiguillettes54506Vandoeuvre Les NancyFrance EcoSustain Environmental Engineering OfficeResearch and DevelopmentKanfen57330France

The increase in the frequency and intensity of drought events expected in the coming decades in Western Europe may disturb forest biogeochemical cycles and create nutrient deficiencies in *** possible origin of nutrient deficiency is the disturbance of the partitioning of the green leaf pool during the leaf senescence period between resorption,foliar leaching and senesced ***,the effects of drought events on this partitioning and the consequences for the maintenance of tree nutrition are poorly *** experiment in a beech forest in meuse(France)was conducted to assess the effect of drought events on nutrient canopy exchanges and on the partitioning of the green leaf pool during the leaf senescence *** aim was to identify potential nutritional consequences of droughts for *** nutrient dynamics,including resorption,chemistry of green and senesced leaves,foliar absorption and leaching in mature beech stands from 2012 to 2019 allowed us to compare the nutrient exchanges for three nondry and three dry years(i.e.,with an intense drought event during the growing season).During dry years,we observed a decrease by almost a third of the potassium(k)partitioning to resorption(*** efficiency),thus reducing the k reserve in trees for the next growing *** result suggests that with the increased drought frequency and intensity expected for the coming decades,there will be a risk of potassium deficiency in trees,as already observed in a rainfall exclusion experiment on the same study *** foliar leaching and higher parititioning to the senesced leaves for k and phosphorus(p)were also *** addition,a slight increase in nitrogen(N)resorption efficiency occurred during dry years which is more likely to improve tree *** calcium(ca)negative resorption decreased,with no apparent consequence in our study *** results show that nutrient exchanges in the canopy and the partitioning of the green leaf

关键词： Natural drought Beech forest canopy resorption Foliar leaching Senesced leaves Nutrition

Laser-induced graphene-coated wearable smart textile electrodes for biopotentials signal monitoring

在线全文

学校读者我要写书评

暂无评论

Frontiers of materials Science 2024年第1期18卷 95-111页

作者： c.m.Vidhya Yogita maithani Sakshi kapoor J.p.Singh Department of physics Indian Institute of Technology DelhiHauz KhasNew Delhi 110016India

This paper describes how to produce a wearable dry electrode at a reasonable cost and how to use it for the monitoring of biopotentials in *** textiles in wearable technologies have made a great advancement in the health care management and living standards of *** was manufactured using the low-cost single-step process,laser ablation of polyimide,a commercial *** dispersions were made using solvent isopropyl alcohol which has low boiling point,nontoxicity,and environmental *** successive coating of the graphene dispersion on the cotton fabric to make it conductive,the sheet resistance of the resulting fabric dropped to 3% of its initial *** laser-induced graphene(LIG)cotton dry electrodes thus manufactured are comparable to Ag/Agcl wet electrodes in terms of the skin-to-electrode impedance,measuring between 78.0 and 7.2 kΩ for the frequency between 40 Hz and 1 *** LIG cotton electrode displayed a signal-to-noise ratio of 20.17 *** to its comfort,simplicity,and good performance over a longer period of time,the textile electrode appears suited for medical applications.

关键词： biopotential electrocardiogram electromyogram flexible electrode textile porous graphene

comparative analysis of microstructure,mechanical,and corrosion properties of biodegradable mg-3Y alloy prepared by selective laser melting and spark plasma sintering

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of magnesium and Alloys 2024年第4期12卷 1496-1510页

作者： p.minárik m.Zemková S.Šašek J.Dittrich m.knapek F.Lukáˇc D.koutný J.Jaroš r.král Faculty of mathematics and physics Charles UniversityKe Karlovu 5Praha 12116Czech Republic research centre University ofŽilinaUniverzitná8215/1Žilina 01026Slovakia Institute of plasma physics of the czech Academy of Sciences Za Slovankou 1782/318200 Praha 8Czech Republic Institute of machine and Industrial Design Brno University of TechnologyTechnická2896/2Brno 61669Czech Republic

This work explored possibilities of biodegradable magnesium alloy mg-3Y preparation by two modern powder metallurgy techniques–spark plasma sintering(SpS)and selective laser melting(SLm).The powder material was consolidated by both methods utilising optimised parameters,which led to very low porosity(∼0.3%)in the SLm material and unmeasurably low porosity in the SpS *** main aim of the study was the thorough microstructure characterisation and interrelation between the microstructure and the functional properties,such as mechanical strength,deformability,and corrosion *** materials showed comparable strength of∼110 mpa in tension and compression and relatively good deformability of∼9%and∼21%for the SLm and SpS materials,*** corrosion resistance of the SpS material in 0.1 m Nacl solution was superior to the SLm one and comparable to the conventional extruded *** digital image correlation during loading and the cross-section analysis of the corrosion layers revealed that the residual porosity and large strained grains have the dominant negative effect on the functional properties of the SLm *** the other hand,one of the primary outcomes of this study is that the SpS consolidation method is very effective in the preparation of the W3 biodegradable alloy,resulting in material with convenient mechanical and degradation properties that might find practical applications.

关键词： magnesium Yttrium powder metallurgy microstructure mechanical strength corrosion resistance

Stock market measures and market performance

在线全文

学校读者我要写书评

暂无评论

Journal of Economic Science research 2020年第2期3卷 31-37页

作者： B.J.Liyanapathirana r.p.k.c.m.ranasinghe Department of mathematics Faculty of Applied SciencesUniversity of Sri JayewardenepuraSri Lanka

Sri Lanka is considered a highly fluctuating economy in the South Asian *** the behavior of economics is of utmost important to obtain the maximum *** market can be considered as one of the key influencers to the economy whereas the behavior of the stock market would highly define the behaviors of the economic *** is required to identify the stock market measures and their contribution for the market development to recognize the influence of stock *** immense importance of its actions on the market performance leads to find more about the stock market’s *** research contains the evidence of the study conducted to identify the stock markets development and behavior measures such as all share price index,market capitalization,dividend yield,price to earnings ratio and shares traded *** of these variables were used to obtain a model to describe and predict performance of stock market over the *** secondary data from the cSE(colombo Stock Exchange)is studied which the trend analysis was conducted for each series of data and results were used for the analysis.A statistical analysis was carried out to identify the measures of stock market depicts that all the measures of the stock market have influences on the stock market development except for the dividend yield,a useful fact in the process of decision making in many aspects.

关键词： Sri Lanka Stock market measures Stock market performance

Effect of radiative loss mechanisms on FIr thermometric parameters of Nd^(3+)-doped lithium tellurite glasses

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of rare Earths 2024年第7期42卷 1250-1257,I0002页

作者： c.Y.morassuti A.p.L Silva L.A.O.Nunes S.m.Lima L.H.c.Andrade Optical and photothermal Spectroscopy Group(GEOF) Center for Studies in Natural Resources(CERNA)State University of Mato Grosso do Sul(UEMS)C.P.351DouradosMSBrazil renato Archer Information Technology center Dom Pedro I Highway(SP-65)Km 1436-Chácaras Campos dos AmaraisCampinasSPBrazil Institute of physics of São carlos University of São PauloSão CarlosSPBrazil

Nd^(3+)-doped tellurite glasses are promising materials for thermometers based on the fluorescence intensity ratio(FIr)***,at high Nd^(3+)concentrations,energy transfer(ET)processes such as optical reabsorption and cross-relaxation can affect the Nd^(3+)emission,which has been little explored in the ***,the present work investigated the use of Nd^(3+)-doped tellurite glass(samples doped with Nd^(3+)at 0.2 mol%,0.5 mol%,2.0 mol%,and 4.0 mol%)in fluorescence thermometers,in the temperature range from 299 to 371 *** results indicate a strong dependence of the FIr parameters on the Nd^(3+)concentration,due to changes in the emission band profiles caused by optical reabsorption of the Nd^(3+)emissions and cross-relaxation processes.A decrease of the relative sensitivity of the ratio^(4)F_(5/2)→^(4)I_(9/2)/^(4)F_(3/2)→^(4)I_(9/2)is observed for samples doped with higher amounts of Nd^(3+).The maximum relative sensitivity at 299 k is 3.00%/k,which is the highest value among the reported Nd^(3+)ions.

关键词： Nd^(3+)-doped tellurite glass Fluorescence intensity ratio Optical thermometry Judd-Ofelt rare earths

Single atom cu-N-c catalysts for the electro-reduction of cO_(2) to cO assessed by rotating ring-disc electrode

在线全文

学校读者我要写书评

暂无评论

Journal of Energy chemistry 2024年第1期88卷 169-182,I0004页

作者： S.pérez-rodríguez m.Gutiérrez-roa c.Giménez-rubio D.ríos-ruiz p.Arévalo-cid m.V.martínez-Huerta A.Zitolo m.J.Lázaro D.Sebastián Instituto de carboquímica(cSIc) Miguel Luesma Castán 450018 ZaragozaSpain Instituto de catálisis y petroleoquímica(cSIc) Marie Curie 228049 MadridSpain Synchrotron SOLEIL L’Orme des MerisiersDépartementale 12891190France

The electrochemical cO_(2) reduction reaction(cO_(2)rr) to controllable chemicals is considered as a promising pathway to store intermittent renewable energy. Herein, a set of catalysts based on copper-nitrogendoped carbon xerogel(cu-N-c) are successfully developed varying the copper amount and the nature of the copper precursor, for the efficient cO_(2)rr. The electrocatalytic performance of cu-N-c materials is assessed by a rotating ring-disc electrode(rrDE), technique still rarely explored for cO_(2)rr. For comparison, products are also characterized by online gas chromatography in a H-cell. The as-synthesized cu-Nc catalysts are found to be active and highly cO selective at low overpotentials(from -0.6 to -0.8 V ***) in 0.1 m kHcO_(3), while H_(2) from the competitive water reduction appears at larger overpotentials(-0.9 V vs. rHE). The optimum copper acetate-derived catalyst containing cu-N_(4) moieties exhibits a cO_(2)-to-cO turnover frequency of 997 h^(-1) at -0.9 V vs. rHE with a H_(2)/cO ratio of 1.8. These results demonstrate that rrDE configuration can be used as a feasible approach for identifying electrolysis products from cO_(2)rr.

关键词： cu-N-c carbon xerogel rotating ring disc electrode carbon dioxide reduction reaction carbon monoxide

crystal structure and luminescence dynamics of highly pure Lim(pO_(3))_(3):Eu^(3+)(m=Sr,ca) red phosphors for white light emitting diodes

在线全文

学校读者我要写书评

暂无评论

Journal of rare Earths 2024年第8期42卷 1470-1478,I0002页

作者： payal khajuria m.manhas A.k.Bedyal Ankush Vij H.c.Swart Vinay kumar Department of physics and Astronomical Sciences Central University of JammuRahy-Suchani.Samba1143J&KIndia Department of physics School of SciencesCluster University of JammuCanal RoadJammu180001India Department of physics University of Petroleum and Energy StudiesDehradunUttarakhand248007India Department of physics University of the Free StatePO.Box 339BloemfonteinZA 9300South Africa

Highly pure red phosphors Lim(pO_(3))_(3):Eu^(3+)(m=Sr,ca) doped with Eu^(3+)(1 mol%) were synthesized via solution combustion method and their crystal structure and luminescence dynamics were studied to explore its suitability in white light emitting *** rietveld refinement analysis of the powder Xray diffraction patterns reveals that the phosphors belong to the pure triclinic phase of LiSr(pO_(3))_(3) and Lica(pO_(3)) with space group p-1(2).The scanning electron microscopy images showed the agglomerated *** photoluminescence emission spectra under 393 nm show an orange band at 594 nm and a red band at 613 nm ascribed to ^(5)D_(0)→^(7)F_(1).^(5)D_(0)→^(7)F_(2) transitions of Eu^(3+)ion in both the ***,the spectroscopic properties such as luminescence behaviour,and Stark splitting were used to examine the symmetry of Eu^(3+)ions in Lim(pO_(3))_(3):Es^(3+)(m=Sr,ca) phosphors in terms of distortion induced upon *** Stark splitting shows that the actual site symmetry for Eu^(3+)ion was estimated to be D_(2) type for both *** photometric properties of Lica(pO_(3))_(3):Eu^(3+)such as commission International de l'Eclairage coordinates(x=0.64,y=0.36) near to the standard one(red),high color purity(95%) and higher brightness reveal that the phosphor has the capability of acting as a red component in n-UV white light emitting diodes.

关键词： photoluminescence phosphate WLEDs Stark splitting rare earths

Direct-Seeded rice: Genetic Improvement of Game-changing Traits for Better Adaption

在线全文

学校读者我要写书评

暂无评论

rice science 2024年第4期31卷 417-433页

作者： priyanka NEGI Jagadish rANE rajendra Sadashiv WAGH Tukaram Jayaram BHOr Dipti Digambar GODSE priyanka JADHAV c.ANILkUmAr Dasari SrEEkANTH k.SAmmI rEDDY Sharad ramrao GADAkH k.m.BOrAIH c.B.HArISHA p.S.BASAVArAJ Indian council of Agricultural research(IcAr)-National Institute of Abiotic Stress management Baramati 413115India mahatma phule krishi Vidyapeeth Rahuri 413722India IcAr-central Institute for Arid Horticulture Bikaner 334006India IcAr-National rice research Institute Cuttack 753006India IcAr-Directorate of Weed research Jabalpur 482004India Dr.panjabrao Deshmukh krishi Vidyapeeth Akola 444104India

The sustainability of rice production continues to be a subject of uncertainty and inquiry attributed to shifts in climatic conditions. In light of the impending climate change crisis and the high labor and water costs accompanying it, direct-seeded rice(DSr) is unquestionably one of the most practical solutions. Despite its resource and climate-friendly advantages, early maturing rice faces weed competitiveness and seedling establishment challenges. resolving these issues is crucial for promoting its wider adoption among farmers, presenting it as a more effective sustainable rice cultivation method globally. Diverse traditional and contemporary breeding methods are employed to mitigate the limitations of the DSr approach, leveraging advanced techniques such as speed breeding and genome editing. Focusing on key traits like mesocotyl length elongation, early seedling vigor, root system architecture, and weed competitiveness holds promise for transformative improvements in DSr adaptation at a broader scale within farming communities. This review aims to summarize how these features contribute to increased crop production in DSr conditions and explore the research efforts focusing on enhancing DSr adaptation through these traits. Emphasizing the pivotal role of these game-changing traits in DSr adaptation, our analysis sheds light on their potential transformative impact and offers valuable insights for advancing DSr practices.

关键词： climate change direct-seeded rice aerobic rice early vigor trait

radiative decays D*(s)→ D(s)γ in covariant confined quark model

在线全文

学校读者我要写书评

暂无评论

chinese physics c 2024年第2期48卷 45-56页

作者： c.T.Tran m.A.Ivanov p.Santorelli Q.c.Vo Department of physics HCMC University of Technology and EducationVo Van Ngan 1700000 Ho Chi Minh CityVietnam Bogoliubov Laboratory of Theoretical physics Joint Institute for Nuclear Research141980 DubnaRussia Dipartimento di Fisica"E.pancini" Universitàdi Napoli Federico ⅡComplesso Universitario di Monte S.AngeloVia CintiaEdificio 680126 NapoliItaly Istituto Nazionale di Fisica Nucleare Sezione di Napoli80126 NapoliItaly University of Science 700000 Ho Chi Minh CityVietnam

radiative decays D((s))*→D((s))γare revisited in light of new experimental data from the BaBar and BESⅢ*** radiative couplings gD*Dγencoding nonperturbative QcD effects are calculated in the framework of the covariant confined quark model developed by *** compare our results with other theoretical studies and experimental *** couplings(in GeV-1)|g(D*+D+γ)|=0.45(9)and|g(D*0D0γ)|=1.72(34)calculated in our model agree with the corresponding experimental data|g(D*+D+γ)|=0.47(7)and|g(D*0D0γ)|=1.77(16).The most interesting case is the decay Ds*→Dsγ,for which a recent prediction based on light-cone sum rules at next-to-leading order|gDs*Dsγ|=0.60(19)deviates from the first(and only to date)lattice QcD result|gDs*Dsγ|=0.11(2)at nearly3σ.Our calculation yields|gDs*Dsγ|=0.29(6),which falls somehow between the two mentioned results,although it is larger than those predicted in other studies using quark models or QcD sum rules.

关键词： covariant quark model radiative decay charmed meson