The formation of wood is affected by the growing season and the environment.Ring-porous tree species have distinct earlywood-latewood differences.However,it is not clear how early wood and latewood respond to drought ...The formation of wood is affected by the growing season and the environment.Ring-porous tree species have distinct earlywood-latewood differences.However,it is not clear how early wood and latewood respond to drought and the differences in adaptation.Therefore,based on the analyses of phenology,growth,and xylem development over a year,xylem development in Fraxinus mandshurica was divided into earlyw ood,transition,and latewood stages.Variation patterns of 38 wood indices from 31 genotypes indicated that the formation of wood tissues was inhibited,and the proportion of xylem cells was affected by drought at each stage.However,soluble sugar affected osmotic regulation only during drought across early wood and transition stages.To maintain water and nutrient transport during drought and to resist embolism risk,drought in the early wood stage leads to varying degrees of early wood vessel diameter reduction,with pits enlarging to compensate.In contrast,during the late wood stage,drought causes latewood vessel diameter to increase and pits to shrink accordingly.In addition,the results indicate that several wood indices correlate with drought resistance at each stage,but early wood vessel diameter,soluble sugar,and latewood ves sel diameters exhibited the strongest correlations in the early wood,transition,and latewood stages.These findings provide clues to understanding plant survival strategies under drought stress and are of significance for plant ecology research on the growth and adaptation of tree species under climate change.展开更多
The growing demand for renewable energy has increased the use of wood pellets as a clean and efficient biomass fuel.This study aims to evaluate the physical properties of wood pellets produced from Acacia hybrid(AC)ve...The growing demand for renewable energy has increased the use of wood pellets as a clean and efficient biomass fuel.This study aims to evaluate the physical properties of wood pellets produced from Acacia hybrid(AC)veneer waste and Pine wood(PW)waste mixed with varying ratios.The objectives are to investigate the effect of different blend ratios ofAcacia hybrid veneer waste and pine wood waste on the physical properties,specificallymoisture content,density,and pellet durability index(PDI)of wood pellets,and to identify the optimal ratio that yields the most desirable pellet quality.The wood pellets were produced by blending Acacia hybrid veneer waste and Pine wood waste(AC:PW)in weight ratios of 100:0,75:25,50:50,25:75,and 0:100.The materials were dried to 10%–12%moisture before pelletizing using a pellet mill under consistent pressure and temperature.Moisture content(MC),density(ρ)and pellet durability index(PDI)were measured following the International Organization for Standardization(ISO).The study found that blending Acacia hybrid veneer waste with Pine wood waste significantly improved pellet density and durability compared to the control.The moisture was lowest in pellets with 50:50 and 25:75 blends,indicating better drying and stability.The blend 50:50 achieves the highest density,and for pellet durability index,the best blend is 25:75,suggesting improved resistance to breakage.Overall,the 50:50 and 25:75 ratios produced pellet with the most desirable combination of low moisture,high density,high durability and the blend meets key ISO 17225 and ENplus quality standards for industrial wood pellet.展开更多
In this paper,the stability of the results of ultrasonic wood surface modification after long-term storage,including macroscopic properties and microstructure of specimens,was investigated.Specimens of aspen wood(Popu...In this paper,the stability of the results of ultrasonic wood surface modification after long-term storage,including macroscopic properties and microstructure of specimens,was investigated.Specimens of aspen wood(Populus tremula)were processed by the developed ultrasonic method of wood surface modification in three different treatment modes and the surface hardness of the specimens was evaluated after processing and after storing the specimens for more than 5 years since long-term stability is an important factor for the use of ultrasonically modified sawn timber as construction and finishing materials.The obtained results of surface hardness measurements by the Leeb method showed that the decrease in hardness after long-term storage is approximately 6.6%for the lowest degree of treatment and approximately 3.4%and 2.4%for medium and high degrees of treatment,taking into account the fact of the average increase in surface hardness approximately 2–4 times,this decrease is insignificant.The internal structure of the specimens after storage was studied by scanning electron microscope(SEM),and deformations of the wood surface layer without damage or rupture were analyzed.The derived stable results confirm the potential of the ultrasonic method for wood surface modification.展开更多
Wood,once regarded primarily as a structural material,possesses rich physicochemical complexity that has long been underexplored.In the context of industrialization and carbon imbalance,it is now emerging as a renewab...Wood,once regarded primarily as a structural material,possesses rich physicochemical complexity that has long been underexplored.In the context of industrialization and carbon imbalance,it is now emerging as a renewable and multifunctional platform for green nanotechnologies.Recent advances in wood nanotechnology have enabled the transformation of natural wood into programmable substrates with tailored nanoarchitectures,establishing it as a representative class of bio-based nanomaterials.This review systematically categorizes wood-specific nanoengineering strategies—including thermal carbonization,laser-induced graphenization,targeted delignification,nanomaterial integration,and mechanical processing—highlighting their mechanisms and impacts on wood's multiscale structural and functional properties.Importantly,these functionalization strategies can be flexibly combined in a modular,“Lego-like”manner,enabling wood to be reconfigured and optimized for diverse application scenarios.We summarize recent progress in applying functionalized wood to sustainable technologies such as energy storage(e.g.,metal-ion batteries,Zn-air systems,supercapacitors),water treatment(e.g.,adsorption,photothermal filtration,catalytic degradation),and energy conversion(e.g.,solar evaporation,ionic thermoelectrics,hydrovoltaics,and triboelectric nanogenerators).These studies reveal how nanoengineered wood structures can enable efficient charge transport,selective adsorption,and enhanced light-to-heat conversion.Finally,the review discusses current challenges—such as scalable fabrication,material integration,and long-term environmental stability—and outlines future directions for the development of wood-based platforms in next-generation green energy and environmental systems.展开更多
Flooding stress is a major adverse condition during the emergence period of direct-seeded rice.This study investigated the use of wood vinegar as a seed soaking treatment to enhance rice seedling rates under flooding ...Flooding stress is a major adverse condition during the emergence period of direct-seeded rice.This study investigated the use of wood vinegar as a seed soaking treatment to enhance rice seedling rates under flooding stress,exploring both the methodology and physiological mechanisms involved.The optimal seed soaking concentration was determined through a gradient experiment,followed by a multi-cultivar validation test.The physiological mechanism of wood vinegar soaking on seedling emergence was analyzed by measuring the electrical conductivity of the flooding water,the changes in starch and soluble sugar contents in the grains and sprouts,and the dynamics ofα-amylase activity and antioxidant-related enzyme activities in the sprouts.The results showed that soaking rice seeds in a wood vinegar solution at a low concentration significantly enhanced the emergence of rice seedlings under flooding conditions,with a 100-fold dilution having the most pronounced effect,increasing seedling rates by 50.6%-60.0%.Further analysis indicated that wood vinegar treatment enhanced seedling establishment by inducing a significant increase inα-amylase activity,leading to a 74.9%-213.6%increase in soluble sugar content in the sprouts during 2-8 d after flooding stress compared with the control.Additionally,the treatment increased superoxide dismutase and peroxidase activities in the sprouts,mitigating lipid peroxidation of the cell membranes,and notably lower water electrical conductivity was observed in wood vinegar-treated seeds compared with the control.In conclusion,soaking rice seeds in a 100-fold diluted wood vinegar solution improves rice seedling rates under flooding stress by mitigating oxidative damage and maintaining energy supply.This approach is valuable for developing cost-effective seed treatment technologies and offering novel strategies to improve seedling rates and uniformity of direct-seeded rice under flooding conditions.展开更多
Accurate prediction of xylem phenology is essential for evaluating the long-term impacts of climate change on carbon sequestration,forest productivity,and ecosystem resilience.However,the environmental controls on xyl...Accurate prediction of xylem phenology is essential for evaluating the long-term impacts of climate change on carbon sequestration,forest productivity,and ecosystem resilience.However,the environmental controls on xylem phenology remain poorly clarified in terms of quantification,particularly for broadleaf species and the process of growth cessation.In this study,we monitored the onset and cessation of wood formation in 19 temperate tree species over periods of up to six years(2019–2024,with observation length varying among species)to assess the impact of environmental changes on the timing of wood formation.Linear mixed-effects models were used to evaluate and quantify the relative importance of photoperiod,forcing,chilling,precipitation,SPEI(standardized precipitation-evapotranspiration index),cold degree days,and MAT(mean annual temperature)to the onset and cessation of wood formation.Photoperiod and forcing temperature were identified as the key drivers of wood formation onset,while photoperiod was the primary factor regulating its cessation.Wood formation onset was less sensitive to photoperiod compared with cessation,but exhibited greater sensitivity to temperature.Conifers were more responsive to changes in day length at onset than broadleaf species,while broadleaf species appeared to rely solely on photoperiod to regulate the cessation,with conifers showing additional modulation by temperature.Moreover,ring-porous species exhibited stronger photoperiodic control of both onset and cessation than diffuse-porous species.These findings highlight the critical role of photoperiod,temperature,or their interactions in regulating xylem phenology,providing insights for improving process-based models that predict xylem growth dynamics.展开更多
Three-dimensional porous foams and aerogels with high compressibilityand elasticity hold great promise for applications in pressure sensing,electromagnetic interference(EMI)shielding,and thermal insulation.However,the...Three-dimensional porous foams and aerogels with high compressibilityand elasticity hold great promise for applications in pressure sensing,electromagnetic interference(EMI)shielding,and thermal insulation.However,their widespread application is often hindered by compromised structural stabilityand inadequate fatigue resistance under repeated compression.Herein,asustainable“top-down”cell wall reconfiguration strategy is proposed to fabricatehighly elastic,fatigue-resistant,and electrically conductive lamellar wood spongefrom natural balsa wood.This strategy involves the conversion of the intrinsiccellular structure of wood into an arch-shaped lamellar architecture reinforcedby chemical cross-linking,followed by coating the lamellar scaffold with conductivepolypyrrole(PPy)via in situ polymerization.The resulting PPy-coatedcross-linked wood sponge(CWS@PPy)demonstrates reversible compressibility,excellent fatigue resistance(∼3.5%plastic deformation after 10,000 cyclesat 40%strain).The strain-induced conductivity changes in CWS@PPy enabletunable EMI shielding effectiveness under cyclic compression and also facilities high-sensitivity pressure sensing(0.72 kPa^(-1)).Additionally,CWS@PPy exhibits a low through-plane thermal conductivity of 0.037 W m^(-1)K^(-1),which can be dynamically tuned for adaptivethermal management.The proposed mechanically robust and conductive wood sponge provides a versatile and sustainable platform fornext-generation smart devices.展开更多
Allometric equations are fundamental tools in ecological research and forestry management,widely used for estimating above-ground biomass and production,serving as the core foundations of dynamic vegetation models.Usi...Allometric equations are fundamental tools in ecological research and forestry management,widely used for estimating above-ground biomass and production,serving as the core foundations of dynamic vegetation models.Using global datasets from Tallo(a tree allometry and crown architecture database encompassing thousands of species)and TRY(a plant traits database),we fit B ayesian hierarchical models with three alternative functional forms(powerlaw,generalized Michaelis-Menten(gMM),and Weibull)to characterize how diameter at breast height(DBH),tree height(H),and crown radius(CR)scale with and without wood density as a species-level predictor.Our analysis revealed that the saturating Weibull function best captured the relationship between tree height and DBH in both functional groups,whereas the CR-DBH relationship was best predicted by a power-law function in angiosperms and by the gMM function in gymnosperms.Although including wood density did not significantly improve predictive performance,it revealed important ecological trade-offs:lighter-wood angiosperms achieve taller mature heights more rapidly,and denser wood promotes wider crown expansion across clades.We also found that accurately estimating DBH required considering both height and crown size,highlighting how these variables together distinguish trees of similar height but differing trunk diameters.Our results emphasize the importance of applying saturating functions for large trees to improve forest biomass estimates and show that wood density,though not always predictive at broad scales,helps illuminate the biomechanical and ecological constraints underlying diverse tree architectures.These findings offer practical pathways for integrating height-and crown-based metrics into existing carbon monitoring programs worldwide.展开更多
Distributions of nuclear magnetic resonance(NMR)relaxation times provide detailed information about the water in wood.This study documents the water dynamics analysis of T_(2)and T_(1)distributions for saturated delig...Distributions of nuclear magnetic resonance(NMR)relaxation times provide detailed information about the water in wood.This study documents the water dynamics analysis of T_(2)and T_(1)distributions for saturated delignified sapwood(DSW),delignified heartwood(DHW)and lignocellulose(LC)samples at different temperatures.Results indicate that below the freezing point of bulk water,free water freezes,causing its signal to disappear from the distribution.Then,the low temperature distributions of the unfrozen bound water contain more information about its components,with DSW,DHW and LC containing two distinct states of bound water(OH bound water(B-water)and more freely bound water(C-water)).Furthermore,it was observed that within the temperature range of−3°C to−60°C,B-water in DSW,DHW and LC maintained a higher unfrozen water content(UWC)value than C-water,and the T_(1)/T_(2)ratios for B-water were consistently higher than that for C-water,indicating that B-water has a greater antifreeze capacity.T_(2)and T_(1)distributions offer different kinds of information about water components,and all peaks within the distribution have been assigned.展开更多
Wood,recognized as a renewable and environmentally sustainable material,plays a crucial role as an alternative energy resource within the construction industry.However,it is highly susceptible to mold and decay fungi,...Wood,recognized as a renewable and environmentally sustainable material,plays a crucial role as an alternative energy resource within the construction industry.However,it is highly susceptible to mold and decay fungi,which can lead to surface discoloration and potentially compromise the structural integrity of wood.The advancement of nanotechnology has introduced innovative strategies for wood protection,enhancing its performance while imparting additional properties.Various approaches including nanosized metals,polymer nanocomposite and coating treatments are actively being explored in this field.Furthermore,integrating bio-based materials with nanotechnology offers a green and sustainable method for wood preservation.This paper provides an analysis,discussion,and synthesis of the applications of nanotechnology in wood protection along with its antifungal mechanisms,thereby contributing novel insights into the research landscape surrounding this topic.展开更多
The impregnation of nanoparticles magnetified into wood had been developed by different methods,like surface chemical coprecipitation and vacuum-pressure coprecipitation of magnetic nanoparticles(NPs).However,there is...The impregnation of nanoparticles magnetified into wood had been developed by different methods,like surface chemical coprecipitation and vacuum-pressure coprecipitation of magnetic nanoparticles(NPs).However,there is a lack of information on the best method to coprecipitation NPs.Then,the present study has the objective to measure the effects of the impregnation process of wood veneers through two in situ processes(immersion and vacuum-pressure)using a solution of FeCl_(3)·6H_(2)O,FeCl_(2)·4H_(2)O and ammonia in three tropical species(Pinus oocarpa,Vochysia ferruginea and Vochysia guatemalensis).It was measured the degree of synthesis of iron NPs using weight and density gains,Fe^(3+) absorption,emission scanning electron microscope(SEM),Fournier transform infrared spectroscopy(FT-IR)and for magnetic properties were measured using vibrating sample magnetometry(VSM).After 5-layer veneer panels were fabricated,we evaluated their physical and mechanical properties.Wood samples impregnated by vacuum-pressure methods showed the higher amount of Fe_(3)O_(4)NPs formation,which was observed in the SEM,X-ray diffraction(XDR),FT-IR and VSM.Vacuum-pressure on treatment presented higher ferrite signals and better magnetic properties.Vochysia ferruginea presented the greatest magnetization properties.The magnetization treated causes probably a degradation of the cell wall,which weakens its mechanical properties,especially internal bonding.展开更多
By means of X ray and gas chromatography analysis, the crystalline structure of untreated wood , alkali treated wood and benzylated wood and their liquefaction in toluene and tetrahydrofufan with HCl as a catalyst we...By means of X ray and gas chromatography analysis, the crystalline structure of untreated wood , alkali treated wood and benzylated wood and their liquefaction in toluene and tetrahydrofufan with HCl as a catalyst were studied .The upper solution of benzylated wood was also studied by GC MS analysis. It proved that the introduction of bulky benzyl group in wood significantly changed the crystalline structure of wood ,enlarging the free volume which facilitated the penetration of solvent into the matrix of treated wood, thus tremendously enhancing thesolubility in solvent,compared to untreated wood and alkali treated wood. The percentage of residue decreased and the combined solvent increased with the increase of weight gain revealed that the liquefaction process became easy. Furthermore, the factors that influenced the liquefaction of benzylated wood were investigated. It showed that the liquefaction performance was improved with the increase of liquefaction time and the amount of catalyst when toluene was used as a solvent, especially in the presence of THF as solvent, there existed the optimum liquefaction time and the amount of catalyst .展开更多
Studies presenting long-term observations of the recruitment and mobility of large wood in mountain watercourses are scarce,but they can considerably contribute to the knowledge of river/riparian forest interactions a...Studies presenting long-term observations of the recruitment and mobility of large wood in mountain watercourses are scarce,but they can considerably contribute to the knowledge of river/riparian forest interactions and the assessment of flood hazard resulting from wood mobility during floods.Widespread dieback of riparian forest along the headwater course of Kamienica Stream in the Polish Carpathians,caused by bark beetle infestation of spruce trees,has raised concerns about potential increases of large wood recruitment to the stream and of the flood hazard to downstream valley reaches.In October 2009,429 trees growing along three sections of the stream were tagged with numbered metal plates and monitored over 10 years to determine the timing and causes of their delivery to the channel and the lengths of their displacement during individual flood events.Moreover,in 2012 the mode of location of wood deposits and a degree of wood decay were determined in the second-to fourth-order stream reaches.The monitoring of tagged trees indicated that trees were recruited to the channel during highintensity meteorological and hydrological events,mostly as a result of bank erosion during floods or windthrow.With 22%of tagged trees recruited to the channel during 10 years,the rate of turnover of the riparian trees was estimated at 45 years.As the riparian area is overgrown with trees with ages up to^160 years,the rate evidences substantial intensification of large wood recruitment to the channel in the recent period.Results of large wood inventory and the 10-year-long monitoring of tagged trees indicated variable mobility of large wood along the upper course of the stream.Wood mobility was negligible in the second-order stream reach,very small in the third-order reach,and greater,but still limited in the fourth-order reach.Wood is transported longer distances only during major floods.However,the advanced state of decay of most pieces leads to their disintegration during floods,precluding distant transport.Thus,large wood retained in the upper stream course does not constitute an important flood hazard to downstream,inhabited valley reaches.展开更多
As the most abundant aromatic bio-based polymer,lignin has great potential as a sustainable feedstock for building crosslinked thermoset polymers as bio-based adhesives.However,the potential of hardwood kraft lignin(H...As the most abundant aromatic bio-based polymer,lignin has great potential as a sustainable feedstock for building crosslinked thermoset polymers as bio-based adhesives.However,the potential of hardwood kraft lignin(HKL)is limited due to its poor crosslinking reactivity.Hence,for the first time,the present study reports the facile oxidation of HKL involving a redox reaction with silver-ammonia complexes([(AgNH3)2]+),primarily focusing on oxidation to produce reactive quinones and promote C-C linkages during reaction.This study aims to increases reactivity of oxidized HKL for effective crosslinking with monoethanolamine(MEA)for the development of bio-based wood adhesives.The characterization,including 13C-nuclear magnetic resonance(NMR)and Fourier transform infrared(FT-IR)spectroscopy,confirms the oxidation reaction,such as the formation of quinones(C=O)and subsequent crosslinking between the oxidized HKL molecules and MEA.Additionally,gel permeation chromatography(GPC)confirms the C-C and C-O linkages with increased molecular weight after oxidation,and is supported by differential scanning calorimetry(DSC)which shows the exothermic reaction due to the crosslinking of the oxidized HKL molecules via condensation to form C-C and C-O linkages.The crosslinked HKL/MEA-based adhesives underwent mild reaction and achieved a maximum dry shear strength of 0.77 MPa,which exceeds the standard requirement of 0.6 MPa.These findings demonstrate not only a one-pot oxidation for improving the reactivity of HKL using silver complexes,but also its facile crosslinking with MEA for sustainable bio-based wood adhesives.展开更多
A high-activity and stable bifunctional oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)electrocatalyst is critical for seawater-based Zn-air batteries(ZABs).Herein,we report a wood-derived chainmail e...A high-activity and stable bifunctional oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)electrocatalyst is critical for seawater-based Zn-air batteries(ZABs).Herein,we report a wood-derived chainmail electrocatalyst containing defective nitrogen-doped carbon nanotubes encapsulating cobalt nanoparticles(Co@D-NCNT/CW)to enhance the ORR/OER activity and stability in seawater medium.During the preparation process,the introduction and removal of Zn increased the defect sites and pyridine N content in the carbon material,modulating charge distribution and influencing the adsorption and activation processes.The highly ordered open channels in Co@D-NCNT/CW promoted mass transfer of reactants and accelerated gas diffusion.The resultant chainmail electrocatalyst exhibited impressive bifunctional ORR and OER activities with an ultra-low gap of 0.67 V in sea water-based alkaline electrolyte.The Co@D-NCNT/CW-assembled seawater-based rechargeable liquid ZABs demonstrated a maximum power density of 245.3 mW cm^(-2)and a long-term cycling performance over 500 h.The seawater-based all-solid-state ZABs achieved the maximum power density of 48.2 mW cm^(-2)and stabilized over 30 h.Density functional theory revealed that the presence of defects and pyridine nitrogen in Co@D-NCNT/CW modulated the electronic structure of Co,optimizing the binding affinity of the Co sites with intermediates and weakening Cl^(-)adsorption.This work provides a new approach to preparing high-activity and stable ORR/OER electrocatalyst utilizing wood nanostructures,boosting the development of seawater-based ZABs.展开更多
The objective of this study was to evaluate the effect of heat treatment on decorative properties including glossiness,color coordinates including lightness(L),blue-yellow(b^(*))and red-green(a^(*)),hardness(shore-D)m...The objective of this study was to evaluate the effect of heat treatment on decorative properties including glossiness,color coordinates including lightness(L),blue-yellow(b^(*))and red-green(a^(*)),hardness(shore-D)morphological characterization and thermal properties of some exotic wood species.Heat treatment of anigre(Aningeria altissima),cedrorana(Cedrelinga catenaeformis),cemara(Casuarina sumatrana)and coronilla(Scutia buxifolia)wood materials were performed in an oven with a programmable controller at 210°C for 3 h.The obtained samples were conditioned in a climate cabin and the decorative properties,morphological characterization with scanning electron microscopy(SEM)and thermal properties with thermogravimetric analyzer(TGA)of the obtained samples were determined.The test results showed that color got darker with heat treatment,specifically L and b^(*)decreased,and a^(*)increased for anigre and cedrorana but a^(*)decreased for cemara and coronilla.The glossiness for all samples generally increased from 20°to 85°but heat treatment decreased the glossiness.The density generally decreased with heat treatment and decrease ratio in the density was found to be in range from 5.6%to 10.6%.According to the SEM analysis,some cracks,pit aspiration and layer decomposition in the micro level of the wood structure were detected.TGA showed that heat treatment makes thermally more stable wood.As a result,it can be said that heat treatment improved the decorative properties of the exotic wood.展开更多
The use of recycled concrete and oyster shells as partial cement and aggregate replacements is ongoing research to solve this multifaceted problem of concrete waste in the construction industry as well as waste from o...The use of recycled concrete and oyster shells as partial cement and aggregate replacements is ongoing research to solve this multifaceted problem of concrete waste in the construction industry as well as waste from oyster shell farming. However, there is a lack of evidence on the possibility of producing a fully recycled composite consisting of recycled concrete and oyster shell without the need for new cement and natural aggregates. In this study, recycled concrete powder (RCP) and oyster shell were used to produce a green composite. Separate ground and combined ground (separate ground and co-ground) RCP and oyster shells are used to determine the effects of grinding approaches on the mechanical and chemical properties of the composite. The composite samples were molded via press molding by applying 30 MPa of pressure for 10 minutes. The results revealed that the composite prepared via the combined ground approach presented the highest flexural strength compared to the separate ground and unground samples. The FTIR and XRD characterization results revealed no chemical or phase alterations in the raw materials or the resulting composites before and after grinding. SEM analysis revealed that combined grinding reduced the particles’ size and improved the dispersion of the mixture, thereby increasing the strength.展开更多
Wood-polymer composites (WPC) were prepared from wood fiber and four kinds of plastics such as PE, PS, ABS, and SAN. The effects of different modifiers on the mechanical properties of the composites were studied. The ...Wood-polymer composites (WPC) were prepared from wood fiber and four kinds of plastics such as PE, PS, ABS, and SAN. The effects of different modifiers on the mechanical properties of the composites were studied. The results showed modifiers could raise the bonding strength of wood fiber with polymer and improve the mechanical properties of the composites. Different modifiers had different effects on the properties of wood-polymer composites, and comparatively the modifier of isocyanate produced a better result. Wood-polymer composite takes not only the advantages of both wood fiber and polymer, but waterproof, dimensional stability and dynamic strength are also significantly improved. Key word Wood fiber - Thermoplastic polyester - Wood-polymer composites - Modifier - Mechanical properties CLC number TB332 Document code A Foundation item: This study was supported by the Harbin Technology Tackle Key Plan (Development Research of Wood-Polymer Composites with High Wood Matrix) and by Heilongjing Nature Science Fund (Composite Mechanism Study of the Wood Polymer).Biography: XU Min (1963-), Female, Associate professor in Material Science and Engineering College, Northeast Forestry University, Harbin 150040, P. R. China.Responsible editor: Chai Ruihai展开更多
This study focuses on the thermophysical characterizations of composite materials made from polypropylene reinforced with residues and fibers from Borassus wood from Chad. These properties are experimentally determine...This study focuses on the thermophysical characterizations of composite materials made from polypropylene reinforced with residues and fibers from Borassus wood from Chad. These properties are experimentally determined at different temperatures using the hot wire method of the “FP2C” machine, where the hot wire probe is inserted between two specimens. The values of the thermal conductivity in powdered Borassus wood range from 0.170 W/mK to 0.182 W/mK for female wood (FNTF) and from 0.169 W/mK to 0.173 W/mK for male wood. For the female and male fibers, the thermal conductivity values range from 0.137 W/mK to 0.157 W/mK for the female and from 0.138 W/mK to 0.168 W/mK for the male. The thermal effusivity of the residues and fibers of Borassus wood varies from: 509.6 Ws1/2/m2K to 543 Ws1/2/m2K for the powder of female wood and from 524.6 Ws1/2/m2K to 547 Ws1/2/m2K for the powder of male wood. For the fibers of Borassus wood, the values range from 410.6 Ws1/2/m2K to 523.6 Ws1/2/m2K for the female wood fibers and from 420.3 Ws1/2/m2K to 480.3 Ws1/2/m2K for the male wood fibers. These results are important for the applications of Borassus wood residues and fibers in construction works regarding the thermal insulation of habitats.展开更多
Adsorbents with three-dimensional porous structures have gained widespread attention due to their unique characteristics,including a large surface area,high porosity,and excellent absorption capacity.One of the produc...Adsorbents with three-dimensional porous structures have gained widespread attention due to their unique characteristics,including a large surface area,high porosity,and excellent absorption capacity.One of the products is the wood sponge.The key to successfully producing wood sponges lies in an optimal multistage delignification process,which is particularly influenced by wood species,solvent,time,and temperature.The aim of this research was to analyze the characteristics of wood sponge derived from sengon wood(Falcataria moluccana Miq.)after multistage delignification.The process involved delignification using NaOH and Na_(2)SO_(3) solutions at 100℃ for 8,9 and 10 h,followed by further delignification in H_(2)O_(2) solution at 100℃ for 1,2,3,and 4 h.The samples were then frozen at -20℃ for 24 h and freeze-dried at -53℃ for 48 h.The results showed that wood sponges treated at 100℃ exhibited lower density,larger pore diameters,brighter color,and superior absorption capacity compared to untreated wood and sponges treated at room temperature for 24 h.FTIR analysis confirmed a decrease in wavelength between 1032–1035 cm^(-1),indicating the degradation of hemicellulose and lignin.XRD analysis revealed that crystallinity increased as amorphous content decreased with prolonged delignification.The wood sponges demonstrated good porosity,with an absorption capacity ranging from 0.65 to 2.24 g/g.The optimal treatment suggested in this research was multistage delignification using NaOH and Na_(2)SO_(3) solution for 10 h,followed by a 1 h treatment with H_(2)O_(2) solution.展开更多
基金supported by the National Key R&D Program of China(2021YFD2200303)the National Natural Science Foundation of China(32271903,U24A20428)。
文摘The formation of wood is affected by the growing season and the environment.Ring-porous tree species have distinct earlywood-latewood differences.However,it is not clear how early wood and latewood respond to drought and the differences in adaptation.Therefore,based on the analyses of phenology,growth,and xylem development over a year,xylem development in Fraxinus mandshurica was divided into earlyw ood,transition,and latewood stages.Variation patterns of 38 wood indices from 31 genotypes indicated that the formation of wood tissues was inhibited,and the proportion of xylem cells was affected by drought at each stage.However,soluble sugar affected osmotic regulation only during drought across early wood and transition stages.To maintain water and nutrient transport during drought and to resist embolism risk,drought in the early wood stage leads to varying degrees of early wood vessel diameter reduction,with pits enlarging to compensate.In contrast,during the late wood stage,drought causes latewood vessel diameter to increase and pits to shrink accordingly.In addition,the results indicate that several wood indices correlate with drought resistance at each stage,but early wood vessel diameter,soluble sugar,and latewood ves sel diameters exhibited the strongest correlations in the early wood,transition,and latewood stages.These findings provide clues to understanding plant survival strategies under drought stress and are of significance for plant ecology research on the growth and adaptation of tree species under climate change.
基金the financial support provided by UMS Great(GUG0670-1/2024),which played a crucial role in the completion of this studyAdditionally,we would like to express our sincere appreciation for the financial assistance and scholarships generously offered by the University of Malaysia Sabah(UMS)throughout the Ministry of Higher Education Malaysia(KPT)throughout the research period.These contributions were invaluable in facilitating our research endeavors.
文摘The growing demand for renewable energy has increased the use of wood pellets as a clean and efficient biomass fuel.This study aims to evaluate the physical properties of wood pellets produced from Acacia hybrid(AC)veneer waste and Pine wood(PW)waste mixed with varying ratios.The objectives are to investigate the effect of different blend ratios ofAcacia hybrid veneer waste and pine wood waste on the physical properties,specificallymoisture content,density,and pellet durability index(PDI)of wood pellets,and to identify the optimal ratio that yields the most desirable pellet quality.The wood pellets were produced by blending Acacia hybrid veneer waste and Pine wood waste(AC:PW)in weight ratios of 100:0,75:25,50:50,25:75,and 0:100.The materials were dried to 10%–12%moisture before pelletizing using a pellet mill under consistent pressure and temperature.Moisture content(MC),density(ρ)and pellet durability index(PDI)were measured following the International Organization for Standardization(ISO).The study found that blending Acacia hybrid veneer waste with Pine wood waste significantly improved pellet density and durability compared to the control.The moisture was lowest in pellets with 50:50 and 25:75 blends,indicating better drying and stability.The blend 50:50 achieves the highest density,and for pellet durability index,the best blend is 25:75,suggesting improved resistance to breakage.Overall,the 50:50 and 25:75 ratios produced pellet with the most desirable combination of low moisture,high density,high durability and the blend meets key ISO 17225 and ENplus quality standards for industrial wood pellet.
文摘In this paper,the stability of the results of ultrasonic wood surface modification after long-term storage,including macroscopic properties and microstructure of specimens,was investigated.Specimens of aspen wood(Populus tremula)were processed by the developed ultrasonic method of wood surface modification in three different treatment modes and the surface hardness of the specimens was evaluated after processing and after storing the specimens for more than 5 years since long-term stability is an important factor for the use of ultrasonically modified sawn timber as construction and finishing materials.The obtained results of surface hardness measurements by the Leeb method showed that the decrease in hardness after long-term storage is approximately 6.6%for the lowest degree of treatment and approximately 3.4%and 2.4%for medium and high degrees of treatment,taking into account the fact of the average increase in surface hardness approximately 2–4 times,this decrease is insignificant.The internal structure of the specimens after storage was studied by scanning electron microscope(SEM),and deformations of the wood surface layer without damage or rupture were analyzed.The derived stable results confirm the potential of the ultrasonic method for wood surface modification.
基金supported by the National Key Research and Development(R&D)Plan(No.2023YFB3209203)National Natural Science Foundation of China(No.62333012,No.92248302)+3 种基金supported by Jiangsu Province Key Laboratory of Embodied Intelligence Robotics Technologythe Collaborative Innovation Center of Suzhou Nano Science&Technologythe 111 ProjectJoint International Research Laboratory of Carbon-Based Functional Materials and Devices。
文摘Wood,once regarded primarily as a structural material,possesses rich physicochemical complexity that has long been underexplored.In the context of industrialization and carbon imbalance,it is now emerging as a renewable and multifunctional platform for green nanotechnologies.Recent advances in wood nanotechnology have enabled the transformation of natural wood into programmable substrates with tailored nanoarchitectures,establishing it as a representative class of bio-based nanomaterials.This review systematically categorizes wood-specific nanoengineering strategies—including thermal carbonization,laser-induced graphenization,targeted delignification,nanomaterial integration,and mechanical processing—highlighting their mechanisms and impacts on wood's multiscale structural and functional properties.Importantly,these functionalization strategies can be flexibly combined in a modular,“Lego-like”manner,enabling wood to be reconfigured and optimized for diverse application scenarios.We summarize recent progress in applying functionalized wood to sustainable technologies such as energy storage(e.g.,metal-ion batteries,Zn-air systems,supercapacitors),water treatment(e.g.,adsorption,photothermal filtration,catalytic degradation),and energy conversion(e.g.,solar evaporation,ionic thermoelectrics,hydrovoltaics,and triboelectric nanogenerators).These studies reveal how nanoengineered wood structures can enable efficient charge transport,selective adsorption,and enhanced light-to-heat conversion.Finally,the review discusses current challenges—such as scalable fabrication,material integration,and long-term environmental stability—and outlines future directions for the development of wood-based platforms in next-generation green energy and environmental systems.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFD2301300)the National Rice Industry Technology System,China(Grant No.CARS-01).
文摘Flooding stress is a major adverse condition during the emergence period of direct-seeded rice.This study investigated the use of wood vinegar as a seed soaking treatment to enhance rice seedling rates under flooding stress,exploring both the methodology and physiological mechanisms involved.The optimal seed soaking concentration was determined through a gradient experiment,followed by a multi-cultivar validation test.The physiological mechanism of wood vinegar soaking on seedling emergence was analyzed by measuring the electrical conductivity of the flooding water,the changes in starch and soluble sugar contents in the grains and sprouts,and the dynamics ofα-amylase activity and antioxidant-related enzyme activities in the sprouts.The results showed that soaking rice seeds in a wood vinegar solution at a low concentration significantly enhanced the emergence of rice seedlings under flooding conditions,with a 100-fold dilution having the most pronounced effect,increasing seedling rates by 50.6%-60.0%.Further analysis indicated that wood vinegar treatment enhanced seedling establishment by inducing a significant increase inα-amylase activity,leading to a 74.9%-213.6%increase in soluble sugar content in the sprouts during 2-8 d after flooding stress compared with the control.Additionally,the treatment increased superoxide dismutase and peroxidase activities in the sprouts,mitigating lipid peroxidation of the cell membranes,and notably lower water electrical conductivity was observed in wood vinegar-treated seeds compared with the control.In conclusion,soaking rice seeds in a 100-fold diluted wood vinegar solution improves rice seedling rates under flooding stress by mitigating oxidative damage and maintaining energy supply.This approach is valuable for developing cost-effective seed treatment technologies and offering novel strategies to improve seedling rates and uniformity of direct-seeded rice under flooding conditions.
基金supported by the Ministry of Science and Technology(No:2019FY101602),China。
文摘Accurate prediction of xylem phenology is essential for evaluating the long-term impacts of climate change on carbon sequestration,forest productivity,and ecosystem resilience.However,the environmental controls on xylem phenology remain poorly clarified in terms of quantification,particularly for broadleaf species and the process of growth cessation.In this study,we monitored the onset and cessation of wood formation in 19 temperate tree species over periods of up to six years(2019–2024,with observation length varying among species)to assess the impact of environmental changes on the timing of wood formation.Linear mixed-effects models were used to evaluate and quantify the relative importance of photoperiod,forcing,chilling,precipitation,SPEI(standardized precipitation-evapotranspiration index),cold degree days,and MAT(mean annual temperature)to the onset and cessation of wood formation.Photoperiod and forcing temperature were identified as the key drivers of wood formation onset,while photoperiod was the primary factor regulating its cessation.Wood formation onset was less sensitive to photoperiod compared with cessation,but exhibited greater sensitivity to temperature.Conifers were more responsive to changes in day length at onset than broadleaf species,while broadleaf species appeared to rely solely on photoperiod to regulate the cessation,with conifers showing additional modulation by temperature.Moreover,ring-porous species exhibited stronger photoperiodic control of both onset and cessation than diffuse-porous species.These findings highlight the critical role of photoperiod,temperature,or their interactions in regulating xylem phenology,providing insights for improving process-based models that predict xylem growth dynamics.
基金supported by the National Natural Science Foundation of China(Grant Nos.32371796 and W2521030).
文摘Three-dimensional porous foams and aerogels with high compressibilityand elasticity hold great promise for applications in pressure sensing,electromagnetic interference(EMI)shielding,and thermal insulation.However,their widespread application is often hindered by compromised structural stabilityand inadequate fatigue resistance under repeated compression.Herein,asustainable“top-down”cell wall reconfiguration strategy is proposed to fabricatehighly elastic,fatigue-resistant,and electrically conductive lamellar wood spongefrom natural balsa wood.This strategy involves the conversion of the intrinsiccellular structure of wood into an arch-shaped lamellar architecture reinforcedby chemical cross-linking,followed by coating the lamellar scaffold with conductivepolypyrrole(PPy)via in situ polymerization.The resulting PPy-coatedcross-linked wood sponge(CWS@PPy)demonstrates reversible compressibility,excellent fatigue resistance(∼3.5%plastic deformation after 10,000 cyclesat 40%strain).The strain-induced conductivity changes in CWS@PPy enabletunable EMI shielding effectiveness under cyclic compression and also facilities high-sensitivity pressure sensing(0.72 kPa^(-1)).Additionally,CWS@PPy exhibits a low through-plane thermal conductivity of 0.037 W m^(-1)K^(-1),which can be dynamically tuned for adaptivethermal management.The proposed mechanically robust and conductive wood sponge provides a versatile and sustainable platform fornext-generation smart devices.
基金supported by the Xingdian Talent Support Program of Yunnan Province(E5YNR03B01)the Xishuangbanna State Rainforest Talent Support Program(E4BN041B01)the CAS President’s International Fellowship Initiative(2020FYB0003)。
文摘Allometric equations are fundamental tools in ecological research and forestry management,widely used for estimating above-ground biomass and production,serving as the core foundations of dynamic vegetation models.Using global datasets from Tallo(a tree allometry and crown architecture database encompassing thousands of species)and TRY(a plant traits database),we fit B ayesian hierarchical models with three alternative functional forms(powerlaw,generalized Michaelis-Menten(gMM),and Weibull)to characterize how diameter at breast height(DBH),tree height(H),and crown radius(CR)scale with and without wood density as a species-level predictor.Our analysis revealed that the saturating Weibull function best captured the relationship between tree height and DBH in both functional groups,whereas the CR-DBH relationship was best predicted by a power-law function in angiosperms and by the gMM function in gymnosperms.Although including wood density did not significantly improve predictive performance,it revealed important ecological trade-offs:lighter-wood angiosperms achieve taller mature heights more rapidly,and denser wood promotes wider crown expansion across clades.We also found that accurately estimating DBH required considering both height and crown size,highlighting how these variables together distinguish trees of similar height but differing trunk diameters.Our results emphasize the importance of applying saturating functions for large trees to improve forest biomass estimates and show that wood density,though not always predictive at broad scales,helps illuminate the biomechanical and ecological constraints underlying diverse tree architectures.These findings offer practical pathways for integrating height-and crown-based metrics into existing carbon monitoring programs worldwide.
基金supported by Natural Science Foundation of Inner Mongolia Autonomous Region of China (2023MS03027)the National Natural Science Foundation of China (31860185 and 31160141)
文摘Distributions of nuclear magnetic resonance(NMR)relaxation times provide detailed information about the water in wood.This study documents the water dynamics analysis of T_(2)and T_(1)distributions for saturated delignified sapwood(DSW),delignified heartwood(DHW)and lignocellulose(LC)samples at different temperatures.Results indicate that below the freezing point of bulk water,free water freezes,causing its signal to disappear from the distribution.Then,the low temperature distributions of the unfrozen bound water contain more information about its components,with DSW,DHW and LC containing two distinct states of bound water(OH bound water(B-water)and more freely bound water(C-water)).Furthermore,it was observed that within the temperature range of−3°C to−60°C,B-water in DSW,DHW and LC maintained a higher unfrozen water content(UWC)value than C-water,and the T_(1)/T_(2)ratios for B-water were consistently higher than that for C-water,indicating that B-water has a greater antifreeze capacity.T_(2)and T_(1)distributions offer different kinds of information about water components,and all peaks within the distribution have been assigned.
基金sponsored by Key Lab.of Biomass Energy and Material,Jiangsu Province(JSBEM-S-202305)Guangdong Academy of Forestry(2022-GDFS-KJ-03).
文摘Wood,recognized as a renewable and environmentally sustainable material,plays a crucial role as an alternative energy resource within the construction industry.However,it is highly susceptible to mold and decay fungi,which can lead to surface discoloration and potentially compromise the structural integrity of wood.The advancement of nanotechnology has introduced innovative strategies for wood protection,enhancing its performance while imparting additional properties.Various approaches including nanosized metals,polymer nanocomposite and coating treatments are actively being explored in this field.Furthermore,integrating bio-based materials with nanotechnology offers a green and sustainable method for wood preservation.This paper provides an analysis,discussion,and synthesis of the applications of nanotechnology in wood protection along with its antifungal mechanisms,thereby contributing novel insights into the research landscape surrounding this topic.
文摘The impregnation of nanoparticles magnetified into wood had been developed by different methods,like surface chemical coprecipitation and vacuum-pressure coprecipitation of magnetic nanoparticles(NPs).However,there is a lack of information on the best method to coprecipitation NPs.Then,the present study has the objective to measure the effects of the impregnation process of wood veneers through two in situ processes(immersion and vacuum-pressure)using a solution of FeCl_(3)·6H_(2)O,FeCl_(2)·4H_(2)O and ammonia in three tropical species(Pinus oocarpa,Vochysia ferruginea and Vochysia guatemalensis).It was measured the degree of synthesis of iron NPs using weight and density gains,Fe^(3+) absorption,emission scanning electron microscope(SEM),Fournier transform infrared spectroscopy(FT-IR)and for magnetic properties were measured using vibrating sample magnetometry(VSM).After 5-layer veneer panels were fabricated,we evaluated their physical and mechanical properties.Wood samples impregnated by vacuum-pressure methods showed the higher amount of Fe_(3)O_(4)NPs formation,which was observed in the SEM,X-ray diffraction(XDR),FT-IR and VSM.Vacuum-pressure on treatment presented higher ferrite signals and better magnetic properties.Vochysia ferruginea presented the greatest magnetization properties.The magnetization treated causes probably a degradation of the cell wall,which weakens its mechanical properties,especially internal bonding.
文摘By means of X ray and gas chromatography analysis, the crystalline structure of untreated wood , alkali treated wood and benzylated wood and their liquefaction in toluene and tetrahydrofufan with HCl as a catalyst were studied .The upper solution of benzylated wood was also studied by GC MS analysis. It proved that the introduction of bulky benzyl group in wood significantly changed the crystalline structure of wood ,enlarging the free volume which facilitated the penetration of solvent into the matrix of treated wood, thus tremendously enhancing thesolubility in solvent,compared to untreated wood and alkali treated wood. The percentage of residue decreased and the combined solvent increased with the increase of weight gain revealed that the liquefaction process became easy. Furthermore, the factors that influenced the liquefaction of benzylated wood were investigated. It showed that the liquefaction performance was improved with the increase of liquefaction time and the amount of catalyst when toluene was used as a solvent, especially in the presence of THF as solvent, there existed the optimum liquefaction time and the amount of catalyst .
基金financed by the statutory funds of the Institute of Nature Conservation,Polish Academy of Sciencesby the project FLORIST(Flood risk on the northern foothills of the Tatra MountainsPSPB no 153/2010)supported by a grant from Switzerland through the Swiss Contribution to the Enlarged European Union。
文摘Studies presenting long-term observations of the recruitment and mobility of large wood in mountain watercourses are scarce,but they can considerably contribute to the knowledge of river/riparian forest interactions and the assessment of flood hazard resulting from wood mobility during floods.Widespread dieback of riparian forest along the headwater course of Kamienica Stream in the Polish Carpathians,caused by bark beetle infestation of spruce trees,has raised concerns about potential increases of large wood recruitment to the stream and of the flood hazard to downstream valley reaches.In October 2009,429 trees growing along three sections of the stream were tagged with numbered metal plates and monitored over 10 years to determine the timing and causes of their delivery to the channel and the lengths of their displacement during individual flood events.Moreover,in 2012 the mode of location of wood deposits and a degree of wood decay were determined in the second-to fourth-order stream reaches.The monitoring of tagged trees indicated that trees were recruited to the channel during highintensity meteorological and hydrological events,mostly as a result of bank erosion during floods or windthrow.With 22%of tagged trees recruited to the channel during 10 years,the rate of turnover of the riparian trees was estimated at 45 years.As the riparian area is overgrown with trees with ages up to^160 years,the rate evidences substantial intensification of large wood recruitment to the channel in the recent period.Results of large wood inventory and the 10-year-long monitoring of tagged trees indicated variable mobility of large wood along the upper course of the stream.Wood mobility was negligible in the second-order stream reach,very small in the third-order reach,and greater,but still limited in the fourth-order reach.Wood is transported longer distances only during major floods.However,the advanced state of decay of most pieces leads to their disintegration during floods,precluding distant transport.Thus,large wood retained in the upper stream course does not constitute an important flood hazard to downstream,inhabited valley reaches.
基金supported by the National Research Foundation(NRF)of Korea,funded by the Korean Government(MSIT)(Grant No.RS-2023-00240043).
文摘As the most abundant aromatic bio-based polymer,lignin has great potential as a sustainable feedstock for building crosslinked thermoset polymers as bio-based adhesives.However,the potential of hardwood kraft lignin(HKL)is limited due to its poor crosslinking reactivity.Hence,for the first time,the present study reports the facile oxidation of HKL involving a redox reaction with silver-ammonia complexes([(AgNH3)2]+),primarily focusing on oxidation to produce reactive quinones and promote C-C linkages during reaction.This study aims to increases reactivity of oxidized HKL for effective crosslinking with monoethanolamine(MEA)for the development of bio-based wood adhesives.The characterization,including 13C-nuclear magnetic resonance(NMR)and Fourier transform infrared(FT-IR)spectroscopy,confirms the oxidation reaction,such as the formation of quinones(C=O)and subsequent crosslinking between the oxidized HKL molecules and MEA.Additionally,gel permeation chromatography(GPC)confirms the C-C and C-O linkages with increased molecular weight after oxidation,and is supported by differential scanning calorimetry(DSC)which shows the exothermic reaction due to the crosslinking of the oxidized HKL molecules via condensation to form C-C and C-O linkages.The crosslinked HKL/MEA-based adhesives underwent mild reaction and achieved a maximum dry shear strength of 0.77 MPa,which exceeds the standard requirement of 0.6 MPa.These findings demonstrate not only a one-pot oxidation for improving the reactivity of HKL using silver complexes,but also its facile crosslinking with MEA for sustainable bio-based wood adhesives.
基金financial support by the Excellent Youth Foundation of Shandong Province(No.ZR2022YQ22)National Natural Science Foundation of China(No.32101451)Youth Innovation Team Project of Shandong Province(No.2022KJ303)。
文摘A high-activity and stable bifunctional oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)electrocatalyst is critical for seawater-based Zn-air batteries(ZABs).Herein,we report a wood-derived chainmail electrocatalyst containing defective nitrogen-doped carbon nanotubes encapsulating cobalt nanoparticles(Co@D-NCNT/CW)to enhance the ORR/OER activity and stability in seawater medium.During the preparation process,the introduction and removal of Zn increased the defect sites and pyridine N content in the carbon material,modulating charge distribution and influencing the adsorption and activation processes.The highly ordered open channels in Co@D-NCNT/CW promoted mass transfer of reactants and accelerated gas diffusion.The resultant chainmail electrocatalyst exhibited impressive bifunctional ORR and OER activities with an ultra-low gap of 0.67 V in sea water-based alkaline electrolyte.The Co@D-NCNT/CW-assembled seawater-based rechargeable liquid ZABs demonstrated a maximum power density of 245.3 mW cm^(-2)and a long-term cycling performance over 500 h.The seawater-based all-solid-state ZABs achieved the maximum power density of 48.2 mW cm^(-2)and stabilized over 30 h.Density functional theory revealed that the presence of defects and pyridine nitrogen in Co@D-NCNT/CW modulated the electronic structure of Co,optimizing the binding affinity of the Co sites with intermediates and weakening Cl^(-)adsorption.This work provides a new approach to preparing high-activity and stable ORR/OER electrocatalyst utilizing wood nanostructures,boosting the development of seawater-based ZABs.
文摘The objective of this study was to evaluate the effect of heat treatment on decorative properties including glossiness,color coordinates including lightness(L),blue-yellow(b^(*))and red-green(a^(*)),hardness(shore-D)morphological characterization and thermal properties of some exotic wood species.Heat treatment of anigre(Aningeria altissima),cedrorana(Cedrelinga catenaeformis),cemara(Casuarina sumatrana)and coronilla(Scutia buxifolia)wood materials were performed in an oven with a programmable controller at 210°C for 3 h.The obtained samples were conditioned in a climate cabin and the decorative properties,morphological characterization with scanning electron microscopy(SEM)and thermal properties with thermogravimetric analyzer(TGA)of the obtained samples were determined.The test results showed that color got darker with heat treatment,specifically L and b^(*)decreased,and a^(*)increased for anigre and cedrorana but a^(*)decreased for cemara and coronilla.The glossiness for all samples generally increased from 20°to 85°but heat treatment decreased the glossiness.The density generally decreased with heat treatment and decrease ratio in the density was found to be in range from 5.6%to 10.6%.According to the SEM analysis,some cracks,pit aspiration and layer decomposition in the micro level of the wood structure were detected.TGA showed that heat treatment makes thermally more stable wood.As a result,it can be said that heat treatment improved the decorative properties of the exotic wood.
文摘The use of recycled concrete and oyster shells as partial cement and aggregate replacements is ongoing research to solve this multifaceted problem of concrete waste in the construction industry as well as waste from oyster shell farming. However, there is a lack of evidence on the possibility of producing a fully recycled composite consisting of recycled concrete and oyster shell without the need for new cement and natural aggregates. In this study, recycled concrete powder (RCP) and oyster shell were used to produce a green composite. Separate ground and combined ground (separate ground and co-ground) RCP and oyster shells are used to determine the effects of grinding approaches on the mechanical and chemical properties of the composite. The composite samples were molded via press molding by applying 30 MPa of pressure for 10 minutes. The results revealed that the composite prepared via the combined ground approach presented the highest flexural strength compared to the separate ground and unground samples. The FTIR and XRD characterization results revealed no chemical or phase alterations in the raw materials or the resulting composites before and after grinding. SEM analysis revealed that combined grinding reduced the particles’ size and improved the dispersion of the mixture, thereby increasing the strength.
基金Supported by the Harbin Technology Tackle Key Plan (Development Research of Wood-Polymer Composites with High Wood Matrix) and by Heilongjing Nature Science Fund (Composite Mechanism Study of the Wood Polymer).
文摘Wood-polymer composites (WPC) were prepared from wood fiber and four kinds of plastics such as PE, PS, ABS, and SAN. The effects of different modifiers on the mechanical properties of the composites were studied. The results showed modifiers could raise the bonding strength of wood fiber with polymer and improve the mechanical properties of the composites. Different modifiers had different effects on the properties of wood-polymer composites, and comparatively the modifier of isocyanate produced a better result. Wood-polymer composite takes not only the advantages of both wood fiber and polymer, but waterproof, dimensional stability and dynamic strength are also significantly improved. Key word Wood fiber - Thermoplastic polyester - Wood-polymer composites - Modifier - Mechanical properties CLC number TB332 Document code A Foundation item: This study was supported by the Harbin Technology Tackle Key Plan (Development Research of Wood-Polymer Composites with High Wood Matrix) and by Heilongjing Nature Science Fund (Composite Mechanism Study of the Wood Polymer).Biography: XU Min (1963-), Female, Associate professor in Material Science and Engineering College, Northeast Forestry University, Harbin 150040, P. R. China.Responsible editor: Chai Ruihai
文摘This study focuses on the thermophysical characterizations of composite materials made from polypropylene reinforced with residues and fibers from Borassus wood from Chad. These properties are experimentally determined at different temperatures using the hot wire method of the “FP2C” machine, where the hot wire probe is inserted between two specimens. The values of the thermal conductivity in powdered Borassus wood range from 0.170 W/mK to 0.182 W/mK for female wood (FNTF) and from 0.169 W/mK to 0.173 W/mK for male wood. For the female and male fibers, the thermal conductivity values range from 0.137 W/mK to 0.157 W/mK for the female and from 0.138 W/mK to 0.168 W/mK for the male. The thermal effusivity of the residues and fibers of Borassus wood varies from: 509.6 Ws1/2/m2K to 543 Ws1/2/m2K for the powder of female wood and from 524.6 Ws1/2/m2K to 547 Ws1/2/m2K for the powder of male wood. For the fibers of Borassus wood, the values range from 410.6 Ws1/2/m2K to 523.6 Ws1/2/m2K for the female wood fibers and from 420.3 Ws1/2/m2K to 480.3 Ws1/2/m2K for the male wood fibers. These results are important for the applications of Borassus wood residues and fibers in construction works regarding the thermal insulation of habitats.
基金funded by New Energy and Industrial Technology Development Organization of Japan(NEDO)—NET ZERO EMISSION TA 2023 BATCH-2—with the Grant Number 28/Ⅲ.5/HK/2023Research Program by Research Organization of Nanotechnology and Materials,National Research and Innovation Agency(Grant Number B-1484/Ⅲ.10/TK.01.00/2/2024)Research Program by Research Assistant,National Research and Innovation Agency(Grant Number B-6932/Ⅱ.5/S1.06.01/9/2023).
文摘Adsorbents with three-dimensional porous structures have gained widespread attention due to their unique characteristics,including a large surface area,high porosity,and excellent absorption capacity.One of the products is the wood sponge.The key to successfully producing wood sponges lies in an optimal multistage delignification process,which is particularly influenced by wood species,solvent,time,and temperature.The aim of this research was to analyze the characteristics of wood sponge derived from sengon wood(Falcataria moluccana Miq.)after multistage delignification.The process involved delignification using NaOH and Na_(2)SO_(3) solutions at 100℃ for 8,9 and 10 h,followed by further delignification in H_(2)O_(2) solution at 100℃ for 1,2,3,and 4 h.The samples were then frozen at -20℃ for 24 h and freeze-dried at -53℃ for 48 h.The results showed that wood sponges treated at 100℃ exhibited lower density,larger pore diameters,brighter color,and superior absorption capacity compared to untreated wood and sponges treated at room temperature for 24 h.FTIR analysis confirmed a decrease in wavelength between 1032–1035 cm^(-1),indicating the degradation of hemicellulose and lignin.XRD analysis revealed that crystallinity increased as amorphous content decreased with prolonged delignification.The wood sponges demonstrated good porosity,with an absorption capacity ranging from 0.65 to 2.24 g/g.The optimal treatment suggested in this research was multistage delignification using NaOH and Na_(2)SO_(3) solution for 10 h,followed by a 1 h treatment with H_(2)O_(2) solution.
