Biochemical components of Moso bamboo(Phyllostachys pubescens)are critical to physiological and ecological processes and play an important role in the material and energy cycles of the ecosystem.The coupled PROSPECT w...Biochemical components of Moso bamboo(Phyllostachys pubescens)are critical to physiological and ecological processes and play an important role in the material and energy cycles of the ecosystem.The coupled PROSPECT with SAIL(PROSAIL)radiative transfer model is widely used for vegetation biochemical component content inversion.However,the presence of leaf-eating pests,such as Pantana phyllostachysae Chao(PPC),weakens the performance of the model for estimating biochemical components of Moso bamboo and thus must be considered.Therefore,this study considered pest-induced stress signals associated with Sentinel-2A/B images and field data and established multiple sets of biochemical canopy reflectance look-up tables(LUTs)based on the PROSAIL framework by setting different parameter ranges according to infestation levels.Quantitative inversions of leaf area index(LAI),leaf chlorophyll content(LCC),and leaf equivalent water thickness(LEWT)were derived.The scale conversions from LCC to canopy chlorophyll content(CCC)and LEWT to canopy equivalent water thickness(CEWT)were calculated.The results showed that LAI,CCC,and CEWT were inversely related with PPC-induced stress.When applying multiple LUTs,the p-values were<0.01;the R2 values for LAI,CCC,and CEWT were 0.71,0.68,and 0.65 with root mean square error(RMSE)(normalized RMSE,NRMSE)values of 0.38(0.16),17.56μg cm-2(0.20),and 0.02 cm(0.51),respectively.Compared to the values obtained for the traditional PROSAIL model,for October,R2 values increased by 0.05 and 0.10 and NRMSE decreased by 0.09 and 0.02 for CCC and CEWT,respectively and RMSE decreased by 0.35μg cm-2 for CCC.The feasibility of the inverse strategy for integrating pest-induced stress factors into the PROSAIL model,while establishing multiple LUTs under different pest-induced damage levels,was successfully demonstrated and can potentially enhance future vegetation parameter inversion and monitoring of bamboo forest health and ecosystems.展开更多
Moso bamboos have attracted excessive attention as a renewable green building material to the concept of sustainable development.In this paper,the 20 bolted Moso bamboo connection specimens with embedded steel plates ...Moso bamboos have attracted excessive attention as a renewable green building material to the concept of sustainable development.In this paper,the 20 bolted Moso bamboo connection specimens with embedded steel plates and grouting materials were designed according to connection configurations with different bolt diameters and end distance of bolt holes,and their bearing capacities and failure modes were analyzed by static tension tests.According to the test results of all connectors,the failure modes of the specimens are divided into four categories,and the effects of bolt diameter and bolt hole end distance on the connection bearing capacity and failure mode are analyzed.The test results show that the deformation and failure process can be divided into four stages.The main influence factor of connector bearing capacity is bolt diameter.Connectors can be divided into four failure modes,and brittle failure can be avoided by adopting certain structural measures.Filling with grouting material can improve the bearing capacity of joints.Due to the large variability of bamboo,further experiments are needed.展开更多
One of the large-scale industrial applications of Moso bamboo and poplar in China is the production of standardized fiberboard.When making fiberboard,a steam blasting pretreatment without the addition of traditional a...One of the large-scale industrial applications of Moso bamboo and poplar in China is the production of standardized fiberboard.When making fiberboard,a steam blasting pretreatment without the addition of traditional adhesives has become increasingly popular because of its environmental friendliness and wide applicability.In this study,the steam explosion pretreatment of Moso bamboo and poplar was conducted.The steam explosion pressure and holding time were varied to determine the influence of these factors on fiber quality by investigating the morphology of the fiber,the mass ratio of the unexploded specimen at the end face,the chemical composition,and the tensile strength.The following conclusions were drawn:As the steam burst pressure and holding time increased,more cellulose and hemicellulose degradation occurred(the degradation of hemicellulose was greater than that of cellulose),the lignin content rose,and the fiber bundle strength decreased.The degradation of bamboo cellulose was slightly higher than that of poplar,and the degradation of poplar hemicellulose was significantly faster than that of bamboo.Furthermore,increasing the steam explosion pressure and pressure holding time could not effectively increase the lignin content.It is recommended to use a steam blasting pressure of 2.5 MPa or 3.0 MPa and a holding time of 180 s to perform steam blasting on bamboo and poplar specimens.展开更多
The wood friction welding technique with its high bonding strength,low cost,high efficiency,and without any adhesive has been increasing concern in China.Moso bamboo(Phyllostachys pubescens)and poplar(Populus sp.)are ...The wood friction welding technique with its high bonding strength,low cost,high efficiency,and without any adhesive has been increasing concern in China.Moso bamboo(Phyllostachys pubescens)and poplar(Populus sp.)are widely planted and used in the furniture industry,interior decoration,and wood structure construction in China.The aim of this work was to investigate the bonding performance of moso bamboo dowel rotation welded joints with different dowel/receiving hole diameter ratios.The results indicated that the ratio of dowel/receiving hole diameter was an important parameter that influenced the welding performance.The bonding strength of the bamboo-to-poplar welded joints at the optimal ratio of 10/7 was as high as 7.50 MPa,which was higher than that of the beech(Fagus sylvatica,L.),schima(Schima superba)dowels and PVAc glued joints.The temperature measurement results showed a peak temperature of bamboo dowel welding as high as 350–360°C.Some differences in the temperature curves between each dowel/hole diameter ratio group were observed at the three different hole depths,such as the friction time,peak temperatures,and stabilization time at the maximum temperature,which could explain the differences in welding strengths between different ratios.The SEM results showed the temperature-induced softening,melting and flowing of cell-interconnected polymer material in the wood and bamboo structure.In addition,the bamboo fibers(mainly vascular bundles)were wrapped to form a dense continuous bonding layer,similar to the reinforced concrete,thus producing a good bonding effect.The Fourier transform-infrared spectroscopy(FT-IR)analyses showed that the high temperature resulted in the increase of the lignin relative content due to the degradation reaction of cellulose in the welding zone,which improved the bonding properties.展开更多
The Moso bamboo,a renewable green building material used in various new green buildings,have received exten-sive attention with the promotion of the concept of green buildings.To explore the mechanical properties of M...The Moso bamboo,a renewable green building material used in various new green buildings,have received exten-sive attention with the promotion of the concept of green buildings.To explore the mechanical properties of Moso bamboo connections with external clamp steel plates,the 16 specimens were designed by changing the bolt diameters and the end distances of the bolt holes.Their static tension tests were conducted to investigate bearing capacities and failure modes of different connection configurations.Based on test results,three failure modes of these connections were obtained,including the shear failure of bolt shank,bearing failure of bolt hole and punch-ing shear failure of the Moso bamboo.The influence of bolt diameters and end distances of bolt holes on bearing capacities of the connections was quantitatively analyzed.Based on a simplified mechanical model,the analytical models were deduced for the bolt shear failure and the bearing failure of bolt holes.The results showed that the predictive values are in substantial agreement with the experimental results.Finally,the design and manufacturing suggestions are recommended for this Moso bamboo connections.展开更多
In this work,we used tensile tests to analyze the tangential failure forms of raw bamboo and determine a relationship between tangential tensile strength,elastic modulus,position,density,and moisture content.We found ...In this work,we used tensile tests to analyze the tangential failure forms of raw bamboo and determine a relationship between tangential tensile strength,elastic modulus,position,density,and moisture content.We found that the tangential mechanical properties of the culm wall were mainly dependent on the mechanical properties of the basic structure of the thin wall.Formulas for calculating the tangential tensile strength of moso bamboo and adjusting the moisture content were also determined.The tangential tensile strength and the tangential tensile modulus of elasticity(TTMOE)followed:outer>middle>inner,and diaphragm>bamboo node>culm wall.Below the fiber saturation point,the tangential tensile strength and TTMOE values of the bamboo gradually decreased with increasing moisture content.When the moisture content was 15%,the tangential tensile strengths of the inner,middle,outer,culm wall,bamboo node,and diaphragm samples of the five-year-old moso bamboo were 3.17,3.29,3.31,3.24,3.67,and 8.85 MPa,respectively.Furthermore,their TTMOE values were 215.09,227.98,238.45,224.04,267.21,and 559.27 MPa,respectively.Hence,this study provides a theoretical basis for future research on bamboo cracking.展开更多
Biomineralization of Si by plants into phytolith formation and precipitation of Si into clays during weathering are two important processes of silicon’s biogeochemical cycle. As a silicon-accumulating plant, the wide...Biomineralization of Si by plants into phytolith formation and precipitation of Si into clays during weathering are two important processes of silicon’s biogeochemical cycle. As a silicon-accumulating plant, the widely distributed and woody Phyl-lostachys heterocycla var. pubescens (moso bamboo) contributes to storing silicon by biomineralization and, thus, prevents eu-trophication of nearby waterbodies through silicon’s erosion of soil particles. A study on the organic pool and biological cycle of silicon (Si) of the moso bamboo community was conducted in Wuyishan Biosphere Reserve, China. The results showed that: (1) the standing crop of the moso bamboo community was 13355.4 g/m2, of which 53.61%, 45.82% and 0.56% are represented by the aboveground and belowground parts of moso bamboos, and the under-story plants, respectively; (2) the annual net primary production of the community was 2887.1 g/(m2·a), among which the aboveground part, belowground part, litterfalls, and other fractions, accounted for 55.86%, 35.30%, 4.50% and 4.34%, respec-tively; (3) silicon concentration in stem, branch, leaf, base of stem, root, whip of bamboos, and other plants was 0.15%, 0.79%, 3.10%, 4.40%, 7.32%, 1.52% and 1.01%, respectively; (4) the total Si accumulated in the standing crop of moso bamboo com-munity was 448.91 g/m2, with 99.83% of Si of the total community stored in moso bamboo populations; (5) within moso bamboo community, the annual uptake, retention, and return of Si were 95.75, 68.43, 27.32 g/(m2·a), respectively; (6) the turnover time of Si, which is the time an average atom of Si remains in the soil before it is recycled into the trees or shrubs, was 16.4 years; (7) the enrichment ratio of Si in the moso bamboo community, which is the ratio of the mean concentration of nutrients in the net primary production to the mean concentration of nutrients in the biomass of a community, was 0.64; and lastly, (8) moso bamboo plants stored about 1.26×1010 kg of silicon in the organic pool made up by the moso bamboo forests in the subtropical area of China.展开更多
Although increasing attention has been paid to upward shift of plant species in altitude as a response to global warming,research on this phenomenon at low altitudinal and low latitudinal zones did not receive enough ...Although increasing attention has been paid to upward shift of plant species in altitude as a response to global warming,research on this phenomenon at low altitudinal and low latitudinal zones did not receive enough attention.In this study,an investigation was carried out to test the relationship between the upward spread of Moso bamboo(Phyllostachys pubescens) along altitudinal gradient and the increasing air temperature over the past decade within the Tianmu Mountain region,situated in southeastern China.Results showed that the peak elevation of Moso bamboo population establishment rose by an average of 9.8 m(±2.7 m) during the past decade and significant correlation existed with mean annual temperature(P < 0.0001,n = 339) but not with annual precipitation(P = 0.7,n = 339),indicating that the upward shift of Moso bamboo along altitudinal gradients was driven primarily by warming temperatures.This upward shift could potentially reduce biodiversity by altering the species composition of the ecosystem.However,there is also the potential for increased carbon sequestration capacity of local forest systems,which would produce an additional carbon sink to combat rising atmospheric CO 2 concentrations and future global warming.展开更多
Recalcitrance of lignocellulosic biomass is closely related to the presence of lignin in secondary cell walls,which has a negative effect on enzyme digestibility,biomass-to-biofuels conversion,and chemical pulping.The...Recalcitrance of lignocellulosic biomass is closely related to the presence of lignin in secondary cell walls,which has a negative effect on enzyme digestibility,biomass-to-biofuels conversion,and chemical pulping.The lignification process and structural heterogeneity of the cell wall for various parts of moso bamboo were investigated.There were slight differences among three different column parts of moso bamboo in terms of chemical compositions,including cellulose,hemicelluloses,and lignin.However,the detailed analysis of the fractionated lignin indicated that the acid-soluble lignin was first biosynthesized,and the largest molecular weight value was detected from the bottom part of the moso bamboo,as well as the highest syringyl-to-guaiacyl ratio.Although the main b-O-4 aryl ethers and resinol structures were clearly present in all lignin samples examined by NMR analysis,the relatively small lignin biomacromolecule in the top part of the moso bamboo lead to poor thermal stability.For the bioconversion process,no significant difference was found among all the moso bamboo samples,and the relatively higher hydrolysis efficiency was largely dependent on the low crystallinity of cellulose rather than the degree of lignin biosynthesis.展开更多
In the Mediterranean region,despite bamboo being an alien species that can seriously alter plant and ani-mal biocoenosis,the area occupied by bamboo plantations continues to increase,especially for the purpose to sequ...In the Mediterranean region,despite bamboo being an alien species that can seriously alter plant and ani-mal biocoenosis,the area occupied by bamboo plantations continues to increase,especially for the purpose to seques-ter carbon(C).However,the C dynamics in the soil-plant system when bamboo is grown outside its native area are poorly understood.Here we investigated the C mitigation potential of the fast-growing Moso bamboo(Phyllostachys edulis)introduced in Italy for climate-change mitigation.We analyzed aboveground(AGB)and belowground(as root/shoot ratio)biomass,litter and soil organic C(SOC)at O-15-and 15-30-cm depths in a 4-year-old bamboo plantation in comparison with the former annual cropland on which the bamboo was established.To have an idea of the maximum C stored at an ecosystem level,a natural forest adjacent the two sites was also considered.In the plantation,C accumulation as AGB was stimulated,with 14.8±3.1 Mg C ha^(-1) stored in 3 years;because thinning was done to remove culms from the first year,the mean sequestration rate was 4.9 Mg C ha^(-1) a^(-1).The sequestration rates were high but comparable to other fast-growing tree species in Italy(e.g.,Pinus nigra).SOC was significantly higher in the bamboo plantation than in the cropland only at the 0-15 cm depth,but SOC stock did not differ.Possibly 4 years were not enough time for a clear increase in SOC,or the high nutrient uptake by bamboos might have depleted the soil nutrients,thus inhibiting the soil organic matter formation by bacteria.In comparison,the natural forest had significantly higher C levels in all the pools.For C dynamics at an ecosystem level,the bamboo plantation on the former annual cropland led to substantial C removal from the atmosphere(about 12 Mg C ha^(-1) a^(-1)).However,despite the promising C sequestration rates by bamboo,its introduction should be carefully considered due to potential ecological problems caused by this species in overexploited environments such as the Mediterranean area.展开更多
The main objective of this research was to study the potential of sodium silicate modification on moso bamboo particles as reinforcements for thermoplastic. Moso bamboo particles were modified with sodium silicate aqu...The main objective of this research was to study the potential of sodium silicate modification on moso bamboo particles as reinforcements for thermoplastic. Moso bamboo particles were modified with sodium silicate aqueous solutions (of 0.5%, 1%, 2%, 5% and 10% concentrations). The mechanical properties of sodium silicate treated moso bamboo particles reinforced PVC composites (BPPC) were calculated and compared with raw bamboo particles filled samples. The thermal characteristics of the BPPC were studied to investigate the feasibility of sodium silicate treatment on moso bamboo particles. The particle morphology and BPPC microstructure were investigated by scanning electron microscopy. Results showed that the tensile strength and modulus of elasticity of the BPPC increased before the concentration of sodium silicate solution reached 5% and got their maximum values of 15.72 MPa and 2956.80 MPa, respectively at 5% concentration. The modulus of rupture obtained the maximum value of 27.73 MPa at 2% concentration. The mechanical curve decreased as the concentration of solution went higher. Differential scanning calorimetric analysis illustrated that the sodium silicate solution treated BPPC possesses a better compatibility. More uniform dispersion of moso bamboo particles in PVC matrix was obtained after the sodium silicate treatment. Hence, the sodium silicate was a feasible and competitive agent of creating moso bamboo particles reinforced PVC composites.展开更多
With the increase of the utilization of bamboo, we must find out more in bamboo properties. According to the national standard GB/T15780 -1995, this paper analyzed the air-dried density and mechanical properties of Mo...With the increase of the utilization of bamboo, we must find out more in bamboo properties. According to the national standard GB/T15780 -1995, this paper analyzed the air-dried density and mechanical properties of Moso bamboo in different ages and stalk parts. The results showed that both the age and the stalk part have remarkable effects on air-dried density and mechanical properties. The effect of age is much more prominent than that of stalk part. The performance shows: upper > middle > down, which increases with the age, and reaches to the peak values at the age of 4 and show a downward trend at the age of 6. According to the tests, the optimum age of bamboo for cutting is about at 4. Moreover, there is a positive correlation between air-dried density and mechanical properties. The correlation coefficients between air-dried density and crushing strength parallel to the grain, bending strength, modulus of elasticity and tensile strength parallel to the grain are 0.917 3, 0.783 9, 0.745 8 and 0.507 4, respectively. In addition, there is a good relativity among mechanical properties, δt: δc: MOR: MOE = 2.79: 1.00: 2.40: 0.15.展开更多
In order to further research bamboo cultivation and expand its application field, air-dried density and mechanical properties of Moso bamboo from the 2 plantations under the same site condition were measured and analy...In order to further research bamboo cultivation and expand its application field, air-dried density and mechanical properties of Moso bamboo from the 2 plantations under the same site condition were measured and analyzed by using the national standard The Testing Methods for Physical and Mechanical Properties of Bamboo (GB / T 15780-1995). And the single linear regression analysis was carried out. The results showed that air-dried density and mechanical properties of the 2 kinds of Moso bamboo increase with the age increasing, and at the same age, those of Moso bamboo from the seedling plantation are much higher than those from the common plantation afforested by transplanting, in other words, Moso bamboo from the conventional plantation reaches a stabilization the at age of 4, while that from the seedling plantation reaches a stabilization at the age of 6 or more. There is a positive correlation between air-dried density and mechanical properties of the 2 kinds of bamboo.展开更多
Drop weight impact tester was used to accurately measure the bending impact resistance of various parts of Phyllostachys edulis,commonly known as moso bamboo,with a growth cycle of 3–8 years.Cellulose crystallinity i...Drop weight impact tester was used to accurately measure the bending impact resistance of various parts of Phyllostachys edulis,commonly known as moso bamboo,with a growth cycle of 3–8 years.Cellulose crystallinity in the bottom(B),middle(M)and top(T)of bamboo at different ages was calculated using peak height analysis in X-ray diffraction.Heatmap of Spearman correlation analysis was used to represent the correlation between chemical composition and impact mechanics.The breaking load(BL),fracture energy(FE)and impact deflection(ID)of 3–8-year-old bamboo were found to be in the range of~670–2120 N,~5.17–15.55 J,and~3.60–~17.76 mm,respectively.As the growth period of bamboo rises,the cellulose crystallinity at the B and T decreases first and then increases,while that for the M increases first and then remains stable.Similarly,the bending impact performance of bamboo was found to become stable with its growth and age.The flexural impact and toughness of the 4-year-old bamboo base material were better than other specimens.The enhancement in the bending impact properties of bamboo at different growth periods was influenced by the lignin content,while the value of FE was mainly positively correlated with ash,cold and hot water extracts and benzyl alcohol content.However the content of holocellulose and pentosan,air-dry density and,base density negatively influenced the FE.With the change in the height of the bamboo,the correlation between its impact mechanical properties and chemical composition gradually decreased.This study provides data support and theoretical basis for the age-appropriate thinning and application of moso bamboo.展开更多
The field trial of Moso bamboo treated with 9 copper preservatives was conducted in Guangzhou, China. The result showed that two formulations of ammonia-based copper azole (F17 and F18 ) and a formulation of amine cop...The field trial of Moso bamboo treated with 9 copper preservatives was conducted in Guangzhou, China. The result showed that two formulations of ammonia-based copper azole (F17 and F18 ) and a formulation of amine copper added with boron (F10), as well as 2 kinds of ammonia-based ACQ, at the copper retention of 3.2 kg/m3 or over, were very resistant to decay and termites after the 5- year field test. And the durability of ACQ-B treated Moso bamboo was similar to that of treated Masson pine and slash pine at the same copper level.展开更多
By PRA survey to 1 245 farmer households of 10 key Moso bamboo (Phyllostachys pubescens) production counties, the source and demand of the management techniques in Zhejiang were studied. The conducted principal factor...By PRA survey to 1 245 farmer households of 10 key Moso bamboo (Phyllostachys pubescens) production counties, the source and demand of the management techniques in Zhejiang were studied. The conducted principal factor analysis revealed that experience and traditional knowledge are currently major technical sources of farmer households' Moso bamboo forest management techniques and that the demonstrative household is a highly expected technical source, in which the prime factor is interpersonal dissemination with the variable information making up 21.5% of the total. The paper thus suggests that following the nationwide collective forest tenure reform and forest land allocation to the households, the technical sources available to the households should be diversified, that technical training with site expert instruction be taken as priority in establishing demonstrative households for extension and that the current technical extension mode await improvement.展开更多
基金funded by the National Natural Science Foundation of China(42071300)the Fujian Province Natural Science(2020J01504)+4 种基金the China Postdoctoral Science Foundation(2018M630728)the Open Fund of Fujian Provincial Key Laboratory of Resources and Environment Monitoring&Sustainable Management and Utilization(ZD202102)the Program for Innovative Research Team in Science and Technology in Fujian Province University(KC190002)the Open Fund of University Key Lab of Geomatics Technology and Optimize Resources Utilization in Fujian Province(fafugeo201901)supported by the Research Project of Jinjiang Fuda Science and Education Park Development Center(2019-JJFDKY-17)。
文摘Biochemical components of Moso bamboo(Phyllostachys pubescens)are critical to physiological and ecological processes and play an important role in the material and energy cycles of the ecosystem.The coupled PROSPECT with SAIL(PROSAIL)radiative transfer model is widely used for vegetation biochemical component content inversion.However,the presence of leaf-eating pests,such as Pantana phyllostachysae Chao(PPC),weakens the performance of the model for estimating biochemical components of Moso bamboo and thus must be considered.Therefore,this study considered pest-induced stress signals associated with Sentinel-2A/B images and field data and established multiple sets of biochemical canopy reflectance look-up tables(LUTs)based on the PROSAIL framework by setting different parameter ranges according to infestation levels.Quantitative inversions of leaf area index(LAI),leaf chlorophyll content(LCC),and leaf equivalent water thickness(LEWT)were derived.The scale conversions from LCC to canopy chlorophyll content(CCC)and LEWT to canopy equivalent water thickness(CEWT)were calculated.The results showed that LAI,CCC,and CEWT were inversely related with PPC-induced stress.When applying multiple LUTs,the p-values were<0.01;the R2 values for LAI,CCC,and CEWT were 0.71,0.68,and 0.65 with root mean square error(RMSE)(normalized RMSE,NRMSE)values of 0.38(0.16),17.56μg cm-2(0.20),and 0.02 cm(0.51),respectively.Compared to the values obtained for the traditional PROSAIL model,for October,R2 values increased by 0.05 and 0.10 and NRMSE decreased by 0.09 and 0.02 for CCC and CEWT,respectively and RMSE decreased by 0.35μg cm-2 for CCC.The feasibility of the inverse strategy for integrating pest-induced stress factors into the PROSAIL model,while establishing multiple LUTs under different pest-induced damage levels,was successfully demonstrated and can potentially enhance future vegetation parameter inversion and monitoring of bamboo forest health and ecosystems.
基金support from 111 Project(Grant No.B18062)the Graduate Research and Innovation Foundation of Chongqing in China(Grant No.CYS20026)the National Key Research and Development Program of China(Grant No.2017YFC0703504).
文摘Moso bamboos have attracted excessive attention as a renewable green building material to the concept of sustainable development.In this paper,the 20 bolted Moso bamboo connection specimens with embedded steel plates and grouting materials were designed according to connection configurations with different bolt diameters and end distance of bolt holes,and their bearing capacities and failure modes were analyzed by static tension tests.According to the test results of all connectors,the failure modes of the specimens are divided into four categories,and the effects of bolt diameter and bolt hole end distance on the connection bearing capacity and failure mode are analyzed.The test results show that the deformation and failure process can be divided into four stages.The main influence factor of connector bearing capacity is bolt diameter.Connectors can be divided into four failure modes,and brittle failure can be avoided by adopting certain structural measures.Filling with grouting material can improve the bearing capacity of joints.Due to the large variability of bamboo,further experiments are needed.
基金We thank Jiangsu Province High-level Talent Selection Training(JNHB-127)the National Key R&D Program of China(2017YFC0703501)+5 种基金the National Natural Science Foundation of China(51878590)Jiangsu Provincial Department of Housing and construction(2018ZD117 and 2019ZD092)the Natural Science Foundation of Jiangsu Province(Grant Nos.BK20170926 and BK20150878)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(Grant No.19KJD220002)the Yangzhou Science and Technology Project(YZ2019047)College Research Project(2019xjzk014)for their funding.
文摘One of the large-scale industrial applications of Moso bamboo and poplar in China is the production of standardized fiberboard.When making fiberboard,a steam blasting pretreatment without the addition of traditional adhesives has become increasingly popular because of its environmental friendliness and wide applicability.In this study,the steam explosion pretreatment of Moso bamboo and poplar was conducted.The steam explosion pressure and holding time were varied to determine the influence of these factors on fiber quality by investigating the morphology of the fiber,the mass ratio of the unexploded specimen at the end face,the chemical composition,and the tensile strength.The following conclusions were drawn:As the steam burst pressure and holding time increased,more cellulose and hemicellulose degradation occurred(the degradation of hemicellulose was greater than that of cellulose),the lignin content rose,and the fiber bundle strength decreased.The degradation of bamboo cellulose was slightly higher than that of poplar,and the degradation of poplar hemicellulose was significantly faster than that of bamboo.Furthermore,increasing the steam explosion pressure and pressure holding time could not effectively increase the lignin content.It is recommended to use a steam blasting pressure of 2.5 MPa or 3.0 MPa and a holding time of 180 s to perform steam blasting on bamboo and poplar specimens.
基金the National Natural Science Foundation of China(31870543)the Youth Science and Technology Innovation Fund of Nanjing Forestry University(cx2016017)+4 种基金the National Key R&D Program of China(2017YFC0703501)the National Natural Science Foundation of China(51878590)Jiangsu Province High-level Talent Selection Training(JNHB-127)Jiangsu Provincial Department of Housing and construction(2018ZD117 and 2019ZD092)the Natural Science Foundation of Jiangsu Province(Grant Nos.BK20170926 and BK20150878)for their funding。
文摘The wood friction welding technique with its high bonding strength,low cost,high efficiency,and without any adhesive has been increasing concern in China.Moso bamboo(Phyllostachys pubescens)and poplar(Populus sp.)are widely planted and used in the furniture industry,interior decoration,and wood structure construction in China.The aim of this work was to investigate the bonding performance of moso bamboo dowel rotation welded joints with different dowel/receiving hole diameter ratios.The results indicated that the ratio of dowel/receiving hole diameter was an important parameter that influenced the welding performance.The bonding strength of the bamboo-to-poplar welded joints at the optimal ratio of 10/7 was as high as 7.50 MPa,which was higher than that of the beech(Fagus sylvatica,L.),schima(Schima superba)dowels and PVAc glued joints.The temperature measurement results showed a peak temperature of bamboo dowel welding as high as 350–360°C.Some differences in the temperature curves between each dowel/hole diameter ratio group were observed at the three different hole depths,such as the friction time,peak temperatures,and stabilization time at the maximum temperature,which could explain the differences in welding strengths between different ratios.The SEM results showed the temperature-induced softening,melting and flowing of cell-interconnected polymer material in the wood and bamboo structure.In addition,the bamboo fibers(mainly vascular bundles)were wrapped to form a dense continuous bonding layer,similar to the reinforced concrete,thus producing a good bonding effect.The Fourier transform-infrared spectroscopy(FT-IR)analyses showed that the high temperature resulted in the increase of the lignin relative content due to the degradation reaction of cellulose in the welding zone,which improved the bonding properties.
基金The authors would like to appreciate the support from the Graduate Research and Innovation Foundation of Chongqing in China(Grant No.CYS20026)the National Key Research and Development Program of China(Grant No.2017YFC0703504).
文摘The Moso bamboo,a renewable green building material used in various new green buildings,have received exten-sive attention with the promotion of the concept of green buildings.To explore the mechanical properties of Moso bamboo connections with external clamp steel plates,the 16 specimens were designed by changing the bolt diameters and the end distances of the bolt holes.Their static tension tests were conducted to investigate bearing capacities and failure modes of different connection configurations.Based on test results,three failure modes of these connections were obtained,including the shear failure of bolt shank,bearing failure of bolt hole and punch-ing shear failure of the Moso bamboo.The influence of bolt diameters and end distances of bolt holes on bearing capacities of the connections was quantitatively analyzed.Based on a simplified mechanical model,the analytical models were deduced for the bolt shear failure and the bearing failure of bolt holes.The results showed that the predictive values are in substantial agreement with the experimental results.Finally,the design and manufacturing suggestions are recommended for this Moso bamboo connections.
基金Sixth Phase of“333 Project”Training Objects in Jiangsu Province,Jiangsu Province High-Level Talent Selection Training(JNHB-127)the National Key R&D Program of China(2017YFC0703501)+3 种基金the National Natural Science Foundation of China(51878590)Jiangsu Provincial Department of Housing and Construction(2019ZD092,2020ZD40 and 2020ZD42)the Natural Science Foundation of Jiangsu Province(Grant Nos.BK20170926,BK20150878 and 20KJB560010)College Research Project(2019xjzk014)for funding this research.
文摘In this work,we used tensile tests to analyze the tangential failure forms of raw bamboo and determine a relationship between tangential tensile strength,elastic modulus,position,density,and moisture content.We found that the tangential mechanical properties of the culm wall were mainly dependent on the mechanical properties of the basic structure of the thin wall.Formulas for calculating the tangential tensile strength of moso bamboo and adjusting the moisture content were also determined.The tangential tensile strength and the tangential tensile modulus of elasticity(TTMOE)followed:outer>middle>inner,and diaphragm>bamboo node>culm wall.Below the fiber saturation point,the tangential tensile strength and TTMOE values of the bamboo gradually decreased with increasing moisture content.When the moisture content was 15%,the tangential tensile strengths of the inner,middle,outer,culm wall,bamboo node,and diaphragm samples of the five-year-old moso bamboo were 3.17,3.29,3.31,3.24,3.67,and 8.85 MPa,respectively.Furthermore,their TTMOE values were 215.09,227.98,238.45,224.04,267.21,and 559.27 MPa,respectively.Hence,this study provides a theoretical basis for future research on bamboo cracking.
基金Project (No. 30370275) supported by the National Natural Science Foundation of China
文摘Biomineralization of Si by plants into phytolith formation and precipitation of Si into clays during weathering are two important processes of silicon’s biogeochemical cycle. As a silicon-accumulating plant, the widely distributed and woody Phyl-lostachys heterocycla var. pubescens (moso bamboo) contributes to storing silicon by biomineralization and, thus, prevents eu-trophication of nearby waterbodies through silicon’s erosion of soil particles. A study on the organic pool and biological cycle of silicon (Si) of the moso bamboo community was conducted in Wuyishan Biosphere Reserve, China. The results showed that: (1) the standing crop of the moso bamboo community was 13355.4 g/m2, of which 53.61%, 45.82% and 0.56% are represented by the aboveground and belowground parts of moso bamboos, and the under-story plants, respectively; (2) the annual net primary production of the community was 2887.1 g/(m2·a), among which the aboveground part, belowground part, litterfalls, and other fractions, accounted for 55.86%, 35.30%, 4.50% and 4.34%, respec-tively; (3) silicon concentration in stem, branch, leaf, base of stem, root, whip of bamboos, and other plants was 0.15%, 0.79%, 3.10%, 4.40%, 7.32%, 1.52% and 1.01%, respectively; (4) the total Si accumulated in the standing crop of moso bamboo com-munity was 448.91 g/m2, with 99.83% of Si of the total community stored in moso bamboo populations; (5) within moso bamboo community, the annual uptake, retention, and return of Si were 95.75, 68.43, 27.32 g/(m2·a), respectively; (6) the turnover time of Si, which is the time an average atom of Si remains in the soil before it is recycled into the trees or shrubs, was 16.4 years; (7) the enrichment ratio of Si in the moso bamboo community, which is the ratio of the mean concentration of nutrients in the net primary production to the mean concentration of nutrients in the biomass of a community, was 0.64; and lastly, (8) moso bamboo plants stored about 1.26×1010 kg of silicon in the organic pool made up by the moso bamboo forests in the subtropical area of China.
基金funded by the National Nature Science Foundation of China (Grant No. 31070440,31270517)China QianRen Program,NSERC-Discovery GrantZhejiang A & F University Research and Development Fund (2012FR023)
文摘Although increasing attention has been paid to upward shift of plant species in altitude as a response to global warming,research on this phenomenon at low altitudinal and low latitudinal zones did not receive enough attention.In this study,an investigation was carried out to test the relationship between the upward spread of Moso bamboo(Phyllostachys pubescens) along altitudinal gradient and the increasing air temperature over the past decade within the Tianmu Mountain region,situated in southeastern China.Results showed that the peak elevation of Moso bamboo population establishment rose by an average of 9.8 m(±2.7 m) during the past decade and significant correlation existed with mean annual temperature(P < 0.0001,n = 339) but not with annual precipitation(P = 0.7,n = 339),indicating that the upward shift of Moso bamboo along altitudinal gradients was driven primarily by warming temperatures.This upward shift could potentially reduce biodiversity by altering the species composition of the ecosystem.However,there is also the potential for increased carbon sequestration capacity of local forest systems,which would produce an additional carbon sink to combat rising atmospheric CO 2 concentrations and future global warming.
基金the financial support from the Natural Science Foundation of China(31770622)the Innovation Program of College of Materials Science and Technology
文摘Recalcitrance of lignocellulosic biomass is closely related to the presence of lignin in secondary cell walls,which has a negative effect on enzyme digestibility,biomass-to-biofuels conversion,and chemical pulping.The lignification process and structural heterogeneity of the cell wall for various parts of moso bamboo were investigated.There were slight differences among three different column parts of moso bamboo in terms of chemical compositions,including cellulose,hemicelluloses,and lignin.However,the detailed analysis of the fractionated lignin indicated that the acid-soluble lignin was first biosynthesized,and the largest molecular weight value was detected from the bottom part of the moso bamboo,as well as the highest syringyl-to-guaiacyl ratio.Although the main b-O-4 aryl ethers and resinol structures were clearly present in all lignin samples examined by NMR analysis,the relatively small lignin biomacromolecule in the top part of the moso bamboo lead to poor thermal stability.For the bioconversion process,no significant difference was found among all the moso bamboo samples,and the relatively higher hydrolysis efficiency was largely dependent on the low crystallinity of cellulose rather than the degree of lignin biosynthesis.
基金supported by the “Project funded by the European Union-Next Generation EU”
文摘In the Mediterranean region,despite bamboo being an alien species that can seriously alter plant and ani-mal biocoenosis,the area occupied by bamboo plantations continues to increase,especially for the purpose to seques-ter carbon(C).However,the C dynamics in the soil-plant system when bamboo is grown outside its native area are poorly understood.Here we investigated the C mitigation potential of the fast-growing Moso bamboo(Phyllostachys edulis)introduced in Italy for climate-change mitigation.We analyzed aboveground(AGB)and belowground(as root/shoot ratio)biomass,litter and soil organic C(SOC)at O-15-and 15-30-cm depths in a 4-year-old bamboo plantation in comparison with the former annual cropland on which the bamboo was established.To have an idea of the maximum C stored at an ecosystem level,a natural forest adjacent the two sites was also considered.In the plantation,C accumulation as AGB was stimulated,with 14.8±3.1 Mg C ha^(-1) stored in 3 years;because thinning was done to remove culms from the first year,the mean sequestration rate was 4.9 Mg C ha^(-1) a^(-1).The sequestration rates were high but comparable to other fast-growing tree species in Italy(e.g.,Pinus nigra).SOC was significantly higher in the bamboo plantation than in the cropland only at the 0-15 cm depth,but SOC stock did not differ.Possibly 4 years were not enough time for a clear increase in SOC,or the high nutrient uptake by bamboos might have depleted the soil nutrients,thus inhibiting the soil organic matter formation by bacteria.In comparison,the natural forest had significantly higher C levels in all the pools.For C dynamics at an ecosystem level,the bamboo plantation on the former annual cropland led to substantial C removal from the atmosphere(about 12 Mg C ha^(-1) a^(-1)).However,despite the promising C sequestration rates by bamboo,its introduction should be carefully considered due to potential ecological problems caused by this species in overexploited environments such as the Mediterranean area.
基金supported by the National High Technology Research and Development Program of China ("863" Project) (Grant No 2009AA043603-2)the Science Fundation of Chinese University and the Education Department of Zhejiang Province (Grant No 200909353)
文摘The main objective of this research was to study the potential of sodium silicate modification on moso bamboo particles as reinforcements for thermoplastic. Moso bamboo particles were modified with sodium silicate aqueous solutions (of 0.5%, 1%, 2%, 5% and 10% concentrations). The mechanical properties of sodium silicate treated moso bamboo particles reinforced PVC composites (BPPC) were calculated and compared with raw bamboo particles filled samples. The thermal characteristics of the BPPC were studied to investigate the feasibility of sodium silicate treatment on moso bamboo particles. The particle morphology and BPPC microstructure were investigated by scanning electron microscopy. Results showed that the tensile strength and modulus of elasticity of the BPPC increased before the concentration of sodium silicate solution reached 5% and got their maximum values of 15.72 MPa and 2956.80 MPa, respectively at 5% concentration. The modulus of rupture obtained the maximum value of 27.73 MPa at 2% concentration. The mechanical curve decreased as the concentration of solution went higher. Differential scanning calorimetric analysis illustrated that the sodium silicate solution treated BPPC possesses a better compatibility. More uniform dispersion of moso bamboo particles in PVC matrix was obtained after the sodium silicate treatment. Hence, the sodium silicate was a feasible and competitive agent of creating moso bamboo particles reinforced PVC composites.
基金supported by The 11th Five-Year Plan: The Project of National Science and Technology Supporting (NO.2006BAD19B0402)
文摘With the increase of the utilization of bamboo, we must find out more in bamboo properties. According to the national standard GB/T15780 -1995, this paper analyzed the air-dried density and mechanical properties of Moso bamboo in different ages and stalk parts. The results showed that both the age and the stalk part have remarkable effects on air-dried density and mechanical properties. The effect of age is much more prominent than that of stalk part. The performance shows: upper > middle > down, which increases with the age, and reaches to the peak values at the age of 4 and show a downward trend at the age of 6. According to the tests, the optimum age of bamboo for cutting is about at 4. Moreover, there is a positive correlation between air-dried density and mechanical properties. The correlation coefficients between air-dried density and crushing strength parallel to the grain, bending strength, modulus of elasticity and tensile strength parallel to the grain are 0.917 3, 0.783 9, 0.745 8 and 0.507 4, respectively. In addition, there is a good relativity among mechanical properties, δt: δc: MOR: MOE = 2.79: 1.00: 2.40: 0.15.
文摘In order to further research bamboo cultivation and expand its application field, air-dried density and mechanical properties of Moso bamboo from the 2 plantations under the same site condition were measured and analyzed by using the national standard The Testing Methods for Physical and Mechanical Properties of Bamboo (GB / T 15780-1995). And the single linear regression analysis was carried out. The results showed that air-dried density and mechanical properties of the 2 kinds of Moso bamboo increase with the age increasing, and at the same age, those of Moso bamboo from the seedling plantation are much higher than those from the common plantation afforested by transplanting, in other words, Moso bamboo from the conventional plantation reaches a stabilization the at age of 4, while that from the seedling plantation reaches a stabilization at the age of 6 or more. There is a positive correlation between air-dried density and mechanical properties of the 2 kinds of bamboo.
基金Fundamental Research on Impact Toughness and Response Mechanism of Bamboo-woven Structural Materials Funded of International Center for Bamboo and Rattan(1632020016).
文摘Drop weight impact tester was used to accurately measure the bending impact resistance of various parts of Phyllostachys edulis,commonly known as moso bamboo,with a growth cycle of 3–8 years.Cellulose crystallinity in the bottom(B),middle(M)and top(T)of bamboo at different ages was calculated using peak height analysis in X-ray diffraction.Heatmap of Spearman correlation analysis was used to represent the correlation between chemical composition and impact mechanics.The breaking load(BL),fracture energy(FE)and impact deflection(ID)of 3–8-year-old bamboo were found to be in the range of~670–2120 N,~5.17–15.55 J,and~3.60–~17.76 mm,respectively.As the growth period of bamboo rises,the cellulose crystallinity at the B and T decreases first and then increases,while that for the M increases first and then remains stable.Similarly,the bending impact performance of bamboo was found to become stable with its growth and age.The flexural impact and toughness of the 4-year-old bamboo base material were better than other specimens.The enhancement in the bending impact properties of bamboo at different growth periods was influenced by the lignin content,while the value of FE was mainly positively correlated with ash,cold and hot water extracts and benzyl alcohol content.However the content of holocellulose and pentosan,air-dry density and,base density negatively influenced the FE.With the change in the height of the bamboo,the correlation between its impact mechanical properties and chemical composition gradually decreased.This study provides data support and theoretical basis for the age-appropriate thinning and application of moso bamboo.
基金supported by the National 11th-five Year Plan (under code 2006BAD19B0405)the national project for publicbenefit (under code 2005DIB5J143)
文摘The field trial of Moso bamboo treated with 9 copper preservatives was conducted in Guangzhou, China. The result showed that two formulations of ammonia-based copper azole (F17 and F18 ) and a formulation of amine copper added with boron (F10), as well as 2 kinds of ammonia-based ACQ, at the copper retention of 3.2 kg/m3 or over, were very resistant to decay and termites after the 5- year field test. And the durability of ACQ-B treated Moso bamboo was similar to that of treated Masson pine and slash pine at the same copper level.
基金sponsored by the Zhejiang Provincial Priority Technological Innovation Platform Program (No.2006C17010)
文摘By PRA survey to 1 245 farmer households of 10 key Moso bamboo (Phyllostachys pubescens) production counties, the source and demand of the management techniques in Zhejiang were studied. The conducted principal factor analysis revealed that experience and traditional knowledge are currently major technical sources of farmer households' Moso bamboo forest management techniques and that the demonstrative household is a highly expected technical source, in which the prime factor is interpersonal dissemination with the variable information making up 21.5% of the total. The paper thus suggests that following the nationwide collective forest tenure reform and forest land allocation to the households, the technical sources available to the households should be diversified, that technical training with site expert instruction be taken as priority in establishing demonstrative households for extension and that the current technical extension mode await improvement.