检索结果-南通市图书馆

Journal of Forestry Research 2024年第5期35卷 26-36页

作者： andrés Baietto andrés Hirigoyen Jorge Hernández Amabelia del Pino Forest Department Faculty of AgronomyUniversity of the Republic12900 MontevideoUruguay National Research Program of Forest Production National Agriculture Research InstituteINIA97000 TacuarembóUruguay Soil and water Department Faculty of AgronomyUniversity of the Republic12900 MontevideoUruguay

Native grasslands in the Pampas of South America are increasingly being replaced by Eucalyptus and Pinus *** short rotation regimes used for the stands require high nutrient levels,with litterfall being a major source of nutrient *** model the litterfall production using climatic variables and assess the nutrient return in 14-year-old Eucalyptus grandis and Pinus taeda stands,we measured litter production over 2 years,using conical litter traps,and monitored climatic *** temperature,accumulated precipitation,and mean maximum vapor pres-sure deficit at the seasonal level influenced litterfall produc-tion by ***;seasonal accumulated precipitation and mean maximum temperature affected litterfall by *** regression tree modeling based on these climatic vari-ables had great accuracy and predictive power for ***(N=33;MAE(mean absolute error)=0.65;RMSE(root mean square error)=0.91;R^(2)=0.71)and ***(N=108;MAE=1.50;RMSE=1.59;R^(2)=0.72).The nutrient return followed a similar pattern to litterfall deposition,as well as the order of importance of macronutrients(***:Ca>N>K>Mg>P;***:N>Ca>K>Mg>P)and micronutrients(*** and ***:Mn>Fe>Zn>Cu)in both *** study constitutes a first approximation of factors that affect litterfall and nutrient return in these systems.

关键词： Afforestation Litterfall Nutrient recycling Climate modeling Myrtaceae Pinaceae

Elevation transition of aquatic insects closely matches a thermal feature in the Yungas of Northwestern Argentina

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2024年第2期21卷 433-448页

作者： Alexandra BUITRAGO-GUACANAME Carlos MOLINERI andrés LIRA-NORIEGA Daniel andrés DOS SANTOS Neotropical Biodiversity Institute(CONICET-UNT) UNT-DomesHorco Molle S/N4107 TucumánArgentina CONACYT Research Fellow Network of Advanced Molecular StudiesInstitute of Ecology A.COld Road to Coatepec 351El HayaCP 91073XalapaVeracruzMexico Biostatistics Chair Faculty of Natural Sciences and IMLNational University of TucumánSan Miguel de TucumánMiguel Lillo 2054000 TucumánArgentina

Temperature is a key factor that shapes the distribution of *** knowledge about how species respond to temperature is relevant to devise strategies for addressing the impacts of climate *** insects are particularly vulnerable to climate change,yet there is still much to learn about their ecology and *** the Yungas ecoregion of Northwestern Argentina,cold-and warm-adapted species of the orders Ephemeroptera,Plecoptera,and Trichoptera(EPT)are segregated by *** modeled the ecological niche of South American EPT species in this region using available data and projected their potential distribution in geographic *** were grouped based on their ecogeographic similarity,and we analyzed their replacement pattern along elevation gradients,focusing on the ecotone where opposing thermal preferences *** this interface,we identified critical points where the combined incidence of cold and warm assemblages maximizes,indicating a significant transition *** found that the Montane Cloud Forest holds the interface,with a particularly greater suitability at its lower *** main axis of the interface runs in a N-S direction and falls between 14°C-16°C mean annual *** probability of a particular location within a basin being classified as part of the interface increases as Kira’s warmth index approaches a score around *** the interface is critical for defining the thermal limits of species distribution and designing biomonitoring *** in the location of thermal constants related to mountainous ecotones may cause vertical displacement of aquatic insects and vegetation *** have recognized significant temperature thresholds that serve as indicators of suitability for the *** global warming is anticipated to shift these indicators,we suggest using them to monitor the imprints of climate change on mountain ecosystems.

关键词： Austral Yungas Ecological Niche Model Ephemeroptera Kira’s warmth index Plecoptera Trichoptera

Developing biophilic intermediate spaces for Arctic housing:Optimizing the thermal,visual,and energy performance

在线全文

学校读者我要写书评

暂无评论

Building Simulation 2024年第6期17卷 857-875页

作者： Tarlan Abazari andréPotvin Louis Gosselin Claude MH Demers GRAP(Groupe de recherche en ambiance physiques) School of ArchitectureLaval UniversityQuébecCanada Department of Mechanical Engineering Faculty of Science and EngineeringLaval UniversityQuébecCanada

Connecting occupants to the outdoor environment and incorporating biophilic design principles are challenging in extreme Arctic climatic *** Arctic housing models do not provide efficient thermal and daylight transitions which are essential for the well-being and cultural needs of their *** address these challenges,this research develops free-running biophilic intermediate spaces,integrated into an existing Arctic housing *** simulation methods are employed to optimize the primary and secondary architectural design variables for 26 case studies of intermediate *** variables include volume,transparency ratio,and *** variables include materials and physical ***,Daylight Factor/Autonomy,and Energy Use are evaluated as performance *** reveal that free-running intermediate spaces with 6 meters depth and a transparency ratio above 50%provide efficient indoor–outdoor transitions regarding thermal,visual,and energy *** architectural configurations contribute to an approximately 5%reduction in energy consumption within the housing unit compared to the *** side windows prevents the risk of overheating during the summer by reducing the average indoor temperature of intermediate spaces by 7°C but increases the overall energy *** a potential alternative to double-glazing,polycarbonate sheets enable efficient thermal performance by increasing the average indoor temperature of intermediate spaces by approximately 15°C during the cold Arctic *** polycarbonate sheets results in a 16.6%reduction in energy consumption compared to using double-glazing material in intermediate space,and a 26%reduction from the *** outcomes contribute to efficient indoor–outdoor connections and energy efficiency in Arctic housing.

关键词： Arctic housing intermediate spaces biophilic design positive thermal transitions daylight availability energy efficiency

Effect of thermo-mechanical conditions during constrained friction processing on the particle refinement of AM50 Mg-alloy phases

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6期12卷 2298-2311页

作者： Camila Caroline de Castro andréMartins Neves Benjamin Klusemann Helmholtz-Zentrum Hereon Institute of Material and Process DesignSolid-State Materials Processing21502 GeesthachtGermany Helmholtz-Zentrum Hereon Institute of Hydrogen TechnologySystem Design for Mobility21502 GeesthachtGermany Helmut Schmidt University/University of the German Federal Armed Forces Hamburg Department of Mechanical and Civil Engineering22043 HamburgGermany Leuphana University Lüneburg Institute for Production Technology and Systems21335 LüneburgGermany

Constrained Friction Processing(CFP)is a novel solid-state processing technique suitable for lightweight materials,such Mg-and *** technique enables grain size refinement to fine or even ultrafine *** this study,the effect of CFP on the microstructural refinement of AM50 rods is investigated in terms of particle size and morphology of the eutectic and secondary phases originally present in the base material,in particular the eutecticβ-Mg_(17)Al_(12)and Al-Mn *** that purpose,as-cast and solution heat-treated base material and processed samples were *** Al_(8)Mn_(5) intermetallic phase was identified as the main secondary phase present in all samples before and after the processing.A notorious refinement of these particles was observed,starting from particles with an average equivalent length of a few micrometers to around 560 nm after the *** refinement of the secondary phase refinement is attributed to a mechanism analogous to the attrition comminution,where the combination of temperature increase and shearing of the material enables the continuous breaking of the brittle intermetallic particles into smaller *** for the eutectic phase,the results indicate the presence of the partially divorcedβ-Mg_(17)Al_(12)particles exclusively in the as-cast base material,indicating that no further phase transformations regarding the eutectic phase,such as dynamic precipitation,occurred after the *** the case of the processed as-cast material analyzed after the CFP,the thermal energy generated during the processing led to temperature values above the solvus limit of the eutectic phase,which associated with the mechanical breakage of the particles,enabled the complete dissolution of this ***,CFP was successfully demonstrated to promote an extensive microstructure refinement in multiple aspects,in terms of grain sizes of theα-Mg phase and presence and morphology of the Al-Mn and eutecticβ-Mg_(17)Al_(12).

关键词： Constrained friction processing AM50 Refill friction stir spot welding Extrusion β-Mg_(17)Al_(12) Al-Mn phases

Assistive Robotics for Upper Limb Physical Rehabilitation:A Systematic Review and Future Prospects

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2024年第4期37卷 50-73页

作者： andrés Guatibonza Leonardo Solaque Alexandra Velasco Lina Peñuela Department of Engineering Mechatronics EngineeringMilitar Nueva Granada UniversityBogotá1101111Colombia

Physical assistive robotics are oriented to support and improve functional capacities of *** physical rehabilitation,robots are indeed useful for functional recovery of affected ***,there are still open questions related to technological *** work presents a systematic review of upper limb rehabilitation robotics in order to analyze and establish technological challenges and future directions in this area.A bibliometric analysis was performed for the systematic literature *** from the last six years,conducted between August 2020 and May 2021,was *** methodology for the literature search and a bibliometric analysis of the metadata are *** a preliminary search resulted in 820 articles,a total of 66 articles were included.A concurrency network and bibliographic analysis were *** an analysis of occurrences,taxonomy,and rehabilitation robotics reported in the literature is *** review aims to provide to the scientific community an overview of the state of the art in assistive robotics for upper limb physical *** literature analysis allows access to a gap of unexplored options to define the technological prospects applied to upper limb physical rehabilitation robotics.

关键词： Upper limb Rehabilitation Assistive robotics Human-machine interaction Robotic systems Virtual reality Rehabilitation monitoring

Semi-analytical calculation model for friction of polymers on the example of POM|PE-UHMw and steel|PE-UHMw

在线全文

学校读者我要写书评

暂无评论

Friction 2024年第10期12卷 2355-2369页

作者： andré BERGMANN Jens SUMPF Niels DALLINGER Martin MONEKE Markus GOLDER Professorship of Conveying Engineering and Materials Handling Chemnitz University of TechnologySachsen 09126Germany Institute of Plastics Engineering Darmstadt University of Applied SciencesDarmstadt 64295Germany

In this paper,a semi-analytical calculation model for the coefficient of friction(COF)of single spherical protrusions is *** allows the prediction of the deformative friction part(μ_(def))and adhesive friction part(μ_(def))of the friction pairings steel|polyethylene with ultra-high molecular weight(PE-UHMw)and polyoxymethylene(POM)|*** experimental studies included unlubricated friction tests,which served to determine the total COF(μ_(def)),as well as tests being lubricated with silicone oil,from whichμ_(def)is *** on the verification tests,it could be shown that both states of lubrication result in the same deformation and that the relationship between the rear angle(w)andμ_(def)postulated in the calculation model is ***,friction tests with segmented spheres were carried out,which allow a specific variation of *** can be concluded that for both pairings theμ_(def)is generally of minor significance(approx.1/3μ_(tot))and the influence of theμ_(adh)predominates(approx.2/3μ_(tot))the friction *** themtot decreases with increasing contact pressure especially in the low pressure range and depends on the form of motion(continuous and discontinuous).

关键词： tribology friction polymers model contact polyoxymethylene(POM) polyethylene with ultra-high molecular weight(PE-UHMw)

Nickel sulfate solution fluoride separation with hydrous zirconium oxide

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Tungsten 2024年第2期6卷 367-381页

作者： Elbert M.Nigri Ummul K.Sultana andré L.A.Santos James w.Vaughan Sonia D.F.Rocha Department of Mining Engineering Federal University of Minas GeraisBelo Horizonte 31270-901Brazil School of Chemical Engineering University of QueenslandSt Lucia 4072Australia

Fluoride is an impurity in nickel sulfate production,which is required for electric vehicle *** zirconium oxide(HZO)was evaluated for removing fl uoride from nickel sulfate *** fluoride removal occurred at pH value 4 and optimal pH value is 4–5,considering Zr *** availability decreases with pH due to hydrogen fluoride and zirconium fluoride aqueous *** removal is initially rapid,with 50 wt.%removal in 7 min,followed by slow removal up to 68 wt.%after 72 h and follows second order rate *** removal was dominated by an ion exchange mechanism and resulting Zr–F bonds were observed using Fourier-transform infrared *** presence of nickel sulfate decreased loading capacity compared to a salt-free *** maintained adsorption capacity through five cycles of loading and regeneration.

关键词： Hydrous zirconium oxide Nickel sulfate Fluoride Adsorption Anion exchange

Grazing Pressure and Plant Functional Types in Puna Highlands,Northwestern Argentina

在线全文

学校读者我要写书评

暂无评论

Phyton-International Journal of Experimental Botany 2024年第5期93卷 1067-1080页

作者： Quiroga Mendiola Mariana Tálamo andrés IPAF NOA—INTA(National Institute for Agricultural Technology) Posta de HornillosJujuy4622Argentina Facultad de Ciencias Naturales Universidad Nacional de SaltaSalta4400Argentina Instituto de Bio y Geociencias del NOA(IBIGEO) UNSa-CONICET.Laboratorio de Ecología Aplicada a la Conservación(LEAC)Facultad de Ciencias NaturalesUniversidad Nacional de SaltaSalta4400Argentina Maestría en Gestión Ambiental Escuela de NegociosUniversidad Católica de Salta(UCASAL)Salta4400Argentina

The Puna grasslands support grazing systems that produce meat and wool in multi-species herds,especially from llama(Lama glama)and ***,it is yet unknown whether grazing pressure can modify grassland structure and Plant Functional Types diversity and cover in Puna *** analyzed the relationship between grazing pressure and Plant Functional Types by comparing transects located near stockyards(high grazing pressure)and far from them(low pressure)and by evaluating the relationship between the Plant Functional Types cover to a Grazing Pressure Index(GPI).This index incorporates the heterogeneity of traditional pastoral *** two ecological sites(Ciénego and Tolar),we sampled paired transects(near-far).Plots near and far from corrals were similar in all the variables measured except for plots in Tolar,which tend to have higher total cover,possibly due to fecal fertilization near ***,we recorded an increase in total cover and grass cover at higher GPI in Ciénego,while in Tolar we found lower values of total cover and herbaceous dicotyledonous cover at intermediate intensities of *** only negative relationship found was the cover of clonal and non-clonal shrubs,possibly explained by the greater use of these shrubs as firewood near *** summary,our study does not show important changes in Plant Functional Types as a function of grazing pressure in the studied grasslands probably because grazing pressure is diluted or diminished when livestock rotates in different areas and grazing durations ***,the long grazing history with which the Puna has evolved could also contribute to the co-structuration between native vegetation and livestock farming.

关键词： Natural grasslands Puna herbivory ecological perturbation

Prediction of net energy of feeds for broiler chickens

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Animal Nutrition 2024年第1期16卷 241-250页

作者： Aye-Cho Tay-Zar Manoosak wongphatcharachai Pairat Srichana Pierre-andré Geraert Jean Noblet Charoen Pokphand Foods Public Company Limited(CPF) BangkokThailand Adisseo France S.A.S. AntonyFrance INRAE RennesFrance

Net energy(NE)enables the prediction of more accurate feed energy values by taking into account the heat increment which is approximately 25%of apparent metabolizable energy(AME)in ***,application of NE in poultry industry has not been practiced *** predict the NE values of broiler diets,23 diets were prepared by using 13 major ingredients(wheat,corn,paddy rice,broken rice,cassava pellets,full-fat soybean,soybean meal,canola meal,animal protein,rice bran,wheat bran,palm kernel meal and palm kernel oil).The diets were formulated in order to meet the birds'requirements and get a wide range of chemical compositions(on DM basis;33.6%to 55.3%for starch;20.8%to 28.4%for CP,2.7%to 10.6%for ether extract[EE]and 7.0%to 17.2%for NDF),with low correlations between these nutrients and low correlations between the inclusion levels of ingredients allowing for the calculation of robust prediction equations of energy values of diets or *** diets were fed to Ross 308 broilers raised in 12 open-circuit respiratory chambers from 18 to 23 d of age(4 birds per cage)and growth performance,diet AME content and heat production were measured,and dietary NE values were *** trial was conducted on a weekly basis with 12 diets measured each week(1per chamber),1 of the 23 diets(reference diet)being measured each *** diet was tested at least *** total,235 energy balance data values were available for the final *** performance,AME(15.3 MJ/kg DM on average)and AME/GE(79.4%on average)values were as *** NE/AME value averaged 76.6%and was negatively influenced by CP and NDF and positively by EE in connection with efficiencies of AME provided by CP,EE and starch for NE of 73%,87%and 81%,*** best prediction equation was:NE=(0.815×AME)—(0.026×CP)+(0.020×EE)—(0.024×NDF)with NE and AME as MJ/kg DM,and CP,EE and NDF as%of *** NE prediction equations from this study agree with other recently reported equation

关键词： Net energy Broiler Poultry Feed evaluation Energy system

同方期刊数据库

Mechanically Joined Extrusion Profiles for Battery Trays

在线全文

学校读者我要写书评

暂无评论

Automotive Innovation 2024年第1期7卷 182-193页

作者： Florian Kneuper Stefan Neumann andréSchulze Mortaza Otroshi A.Erman Tekkaya Gerson Meschut Institute of Forming Technology and Lightweight Components(IUL) TU Dortmund University44227 DortmundGermany Laboratory for Material and Joining Technology(LwF) Paderborn UniversityPaderbornGermany

In the context of electromobility,ensuring the leak tightness of assemblies is of paramount importance,particularly in bat-tery *** battery housings,often featuring base assemblies crafted from extruded aluminum profiles,address the challenge of leak tightness at joints through methods like friction stir welding,a process known for its time and cost *** aim of this study is to develop and implement a new type of extruded profile concept to produce tight base assemblies for battery housings by a longitudinal mechanical single stroke joining *** geometry,the process and the properties of the aluminum profiles are investigated to get a joint that meets the tightness requirements and achieve high load-bearing capacities in agreement with the high homologation requirements set to vehicles with high-voltage *** joint is formed by means of a single stage press stroke,which eliminates the need for complex tool designs that are neces-sary for continuous joining(roll joining).Flat steel contact surfaces are used as joining *** evaluate the joint quality,force curves from the joining process are analyzed and the resulting joint geometries are assessed using *** resulting leak tightness of the linear joints is measured by a helium sniffer leak detector and the load-bearing capacities are investigated by shear lap and bending tests and fatigue strength *** study also explores whether a difference in strength between the two joining partners has a positive effect on the joint properties.

关键词： Joining by plastic deformation Aluminum Leak Tightness