[Objective]The paper was to study the effect of continuous cropping on leaf nutrient and growth of different species of poplar plantation.[Method] The tree height,diameter at breast height（DBH）,volume of different g...[Objective]The paper was to study the effect of continuous cropping on leaf nutrient and growth of different species of poplar plantation.[Method] The tree height,diameter at breast height（DBH）,volume of different generations and species of poplar plantation in poplar production area in northern Jiangsu Province,as well as TN,TP and TK content in their leaves were determined through field investigation and indoor experiment.[Result] With the increasing generation,the changes of TN,TP and TK content in the leaves of different ages of two varieties of forest stand were also different.However,with the increasing tree ages,TN,TP and TK contents in leaves showed decrease trend.With the increasing generation,the changes of tree height of I-69 and I-72 poplar showed the similar trend.The effect of increasing generation on tree height of 7-year-old and 10-year-old poplar was relatively stable,showing decrease trend from generation to generation.The tree height of 4-year-old poplar first increased and then decreased with the increasing generation.The changes of DBH along with different generations were basically consistent with the changes of tree height.With the increasing cultivation generations,the volume of 7-year-old and 10-year-old poplar decreased with significant difference.[Conclusion ] The result provided basis for rational fertilization and management of poplar plantation,improvement of productivity of poplar plantation,and achievement of sustainable management of plantation.展开更多
The microfibril angle of seven poplar clones was determined by using X-ray diffraction technique. Microfibril angle, wood basic density, fiber length, fiber width and cellulose content were assessed for every growth r...The microfibril angle of seven poplar clones was determined by using X-ray diffraction technique. Microfibril angle, wood basic density, fiber length, fiber width and cellulose content were assessed for every growth ring at breast height for all sample trees. Significant variation in microfibril angle was observed among growth rings. Mean microfibril angle (MFA) at breast height varied from 7.8?to 28?between growth rings with cambial age and showed a consistent pith-to-bark trend of decline an-gles. Analysis of variance also indicated that there were significant differences in wood basic density, fiber length, fiber width and cellulose content between the growth rings, which had an increasing tendency from pith to bark. Correlations between MFA and examined wood properties were predominantly large and significant negative (?0.01), and the coefficients were -0.660 for cellulose content, -0.586 for fiber length, -0.516 for fiber width and -0.450 for wood basic density, respectively. Regression analysis with linear and curve estimation indicated that a quadratic function showed the largest R2 and the least standard error for describing the relationships between microfibril angle and measured wood properties, and the correlation coefficients were over -0.45 (n=125). The results from this study suggested that microfibril angle would be a good characteristic for improvement in the future breeding program of poplars.展开更多
A study was conducted on the isolation of poplar （Populusxeurarnaricana （Dode） Guineir cv. I -72/58） wood components with aqueous acetic acid （AcOH） containing small amounts of sulfuric acid. The reaction time, ...A study was conducted on the isolation of poplar （Populusxeurarnaricana （Dode） Guineir cv. I -72/58） wood components with aqueous acetic acid （AcOH） containing small amounts of sulfuric acid. The reaction time, concentration of acetic acid, ratio of liquor to wood, and concentration of acid catalyst were investigated to examine their effects on the fractionation of wood components. The three main separated components were characterized. The results showed that the optimum conditions for fractionation of poplar wood components were： 0.3% H2SO4 in reaction solution, ratio of liquor to wood 6, reflux time 3 h, and 90% AcOH. The residues were mainly composed of a-Cellulose and hemicellulose, The water insoluble precipitate （acetic acid lignin, AcL） had a low weight-average molecular weight range from 341 to 253 （Mw） and a narrow molecular weight distribution from 1.1 to 1.2. The sugar analysis revealed the solubilized products resulted mainly from hemicellulose and exited as monosaccharides.展开更多
The wood basic density, cellulose content and fiber form were investigated for all sample trees at breast height (1.3 m) in seven poplar clones, and at 0 (butt), 5.6, 9.6, 13.6, 17.6, 19.6 and 21.6 m for clone Nanlin-...The wood basic density, cellulose content and fiber form were investigated for all sample trees at breast height (1.3 m) in seven poplar clones, and at 0 (butt), 5.6, 9.6, 13.6, 17.6, 19.6 and 21.6 m for clone Nanlin-95 and Nanlin-895, respectively, for providing information on variation patterns of wood density, fiber characteristics and holocellulose content within trees and among clones. The results showed that significant variations about wood density, cellulose content, fiber diameter and the ratio of fiber length to diameter existed among poplar clones examined. Variance analysis indicated that there were significant differences in wood basic density, fiber length, fiber diameter and cellulose content among the growth rings, which had an increasing tendency along the direction from pith to bark. The significant differences also existed in wood basic density, fiber length and fiber diameter at different tree height. The mean wood basic density had a general increase trend with increasing height of trees and the lowest was found at the base, while fiber length and fiber diameter had a general decline pattern with increasing height of trees and the biggest value was observed at the height of 5.6 m. Regression analysis indicated that the relationship between examined wood properties and growth ring number (cambial age), and the relationship between examined wood properties and tree height can be described by polynomial functions.展开更多
With the aim of creating biodegradable materials for medical devices clinical appointments with high hemocompatibility we have developed a new polymer product.The basis of this product is plasticized by polyethylene g...With the aim of creating biodegradable materials for medical devices clinical appointments with high hemocompatibility we have developed a new polymer product.The basis of this product is plasticized by polyethylene glycol bacterial copolymer of hydroxybutyrate and oxovalerate. A well-known antitbrombotic supplement--acetylsalicylic acid has been added to improve hemocompatibility in the polymer. The results of our studies showed a controlled prolonged separation of acetylsalicylic acid from polymeric material in the blood. We studied in vitro the dynamics of liberation of acetylsalicylic acid from polymeric coatings. It was shown that the concentration of polyethylene glycol and the thickness of the polymer layer can affect the rate of diffusion of acetylsalicylic acid from polymer films.展开更多
Computer simulation was carried out on fiber length and width for plantation-grown Chinesewhite poplar (Populus tomentosa Carr. clone) and plantation-grown poplar I-72 (P. x eurumericana (Dode)Guiner cv.). Skewness an...Computer simulation was carried out on fiber length and width for plantation-grown Chinesewhite poplar (Populus tomentosa Carr. clone) and plantation-grown poplar I-72 (P. x eurumericana (Dode)Guiner cv.). Skewness and kurtosis of measured results exhibited that distributions of the fiber length andwidth departured from normal distribution. Three-parameter Weibull density function was used in thisinvestigation and the corresponding program was written with Turbo C. The results showed that profiles ofsimulated length and width histograms were similar to ones of measured histograms, and that there was apretty good agreement between simulated and measured means of fiber length and width. There was a littleinfluence on the simulated means from seed used in random number generator and number of simulatedvariables. That indicated that the simulation was steady when the seed and the number were altered. Differenthistograms can be obtained with different values of the location, the shape, and the scale parameter correspondingto different values of the minimum, the mean, and the standard deviation for fiber length and width. Thesimulation presented here can be used as a tool for the studies on the variations in fiber morphology.展开更多
In order to study the influence of wood microstructure on wood dyeing, eleven parameters of wood microstructure and 5 parameters of wood dyeing effects for 34 pieces of wood boards from 5 trees of Chinese white poplar...In order to study the influence of wood microstructure on wood dyeing, eleven parameters of wood microstructure and 5 parameters of wood dyeing effects for 34 pieces of wood boards from 5 trees of Chinese white poplar (Populus tomentosa) were determined and the multiple regression analysis between the factors of wood microstructures and the parameters of wood dyeing effects were made. The regression results show that each variable of wood dyeing effects has higher relationship with wood microstructures, and multiple correlation coefficients between each variable of wood dyeing effects and wood microstructures are 0.483 6~0.799 8. The main factors of wood microstructures influencing wood dyeing of Chinese white poplar are proportion of wood ray, proportion of vessel and proportion of wood fiber according to comparing the standardized regression coefficients of multiple regression equation.展开更多
The drying characteristic was studied for plantation wood of Chinese fir and poplar, which are typical plantation wood of southern and northern part of China, respectively. Through 100-degree-method the drying charact...The drying characteristic was studied for plantation wood of Chinese fir and poplar, which are typical plantation wood of southern and northern part of China, respectively. Through 100-degree-method the drying characteristic and basic drying condition were gotten, then drying schedule was developed for practical drying, the results showed that the drying schedule is suitable for Chinese fir and poplar plantation lumber, but shrinkage is large. The recommendation was made that enough dead weight is needed to decrease shrinkage in drying process. The drying quality of the two species of lumber is good in conventional drying method.展开更多
基金Supported by National 948 Project(2011-4-63)Special Research Fund for Welfare Act of State Forestry(200904001-3)Youth Fund of Anhui Normal University(2009xqn73)~~
文摘[Objective]The paper was to study the effect of continuous cropping on leaf nutrient and growth of different species of poplar plantation.[Method] The tree height,diameter at breast height（DBH）,volume of different generations and species of poplar plantation in poplar production area in northern Jiangsu Province,as well as TN,TP and TK content in their leaves were determined through field investigation and indoor experiment.[Result] With the increasing generation,the changes of TN,TP and TK content in the leaves of different ages of two varieties of forest stand were also different.However,with the increasing tree ages,TN,TP and TK contents in leaves showed decrease trend.With the increasing generation,the changes of tree height of I-69 and I-72 poplar showed the similar trend.The effect of increasing generation on tree height of 7-year-old and 10-year-old poplar was relatively stable,showing decrease trend from generation to generation.The tree height of 4-year-old poplar first increased and then decreased with the increasing generation.The changes of DBH along with different generations were basically consistent with the changes of tree height.With the increasing cultivation generations,the volume of 7-year-old and 10-year-old poplar decreased with significant difference.[Conclusion ] The result provided basis for rational fertilization and management of poplar plantation,improvement of productivity of poplar plantation,and achievement of sustainable management of plantation.
基金This research was supported by National Natural Science Foundation of China (Grant No. 30070616).
文摘The microfibril angle of seven poplar clones was determined by using X-ray diffraction technique. Microfibril angle, wood basic density, fiber length, fiber width and cellulose content were assessed for every growth ring at breast height for all sample trees. Significant variation in microfibril angle was observed among growth rings. Mean microfibril angle (MFA) at breast height varied from 7.8?to 28?between growth rings with cambial age and showed a consistent pith-to-bark trend of decline an-gles. Analysis of variance also indicated that there were significant differences in wood basic density, fiber length, fiber width and cellulose content between the growth rings, which had an increasing tendency from pith to bark. Correlations between MFA and examined wood properties were predominantly large and significant negative (?0.01), and the coefficients were -0.660 for cellulose content, -0.586 for fiber length, -0.516 for fiber width and -0.450 for wood basic density, respectively. Regression analysis with linear and curve estimation indicated that a quadratic function showed the largest R2 and the least standard error for describing the relationships between microfibril angle and measured wood properties, and the correlation coefficients were over -0.45 (n=125). The results from this study suggested that microfibril angle would be a good characteristic for improvement in the future breeding program of poplars.
文摘A study was conducted on the isolation of poplar （Populusxeurarnaricana （Dode） Guineir cv. I -72/58） wood components with aqueous acetic acid （AcOH） containing small amounts of sulfuric acid. The reaction time, concentration of acetic acid, ratio of liquor to wood, and concentration of acid catalyst were investigated to examine their effects on the fractionation of wood components. The three main separated components were characterized. The results showed that the optimum conditions for fractionation of poplar wood components were： 0.3% H2SO4 in reaction solution, ratio of liquor to wood 6, reflux time 3 h, and 90% AcOH. The residues were mainly composed of a-Cellulose and hemicellulose, The water insoluble precipitate （acetic acid lignin, AcL） had a low weight-average molecular weight range from 341 to 253 （Mw） and a narrow molecular weight distribution from 1.1 to 1.2. The sugar analysis revealed the solubilized products resulted mainly from hemicellulose and exited as monosaccharides.
基金This study was supported by National Natural Science Foundation of China, (No. 30070616).
文摘The wood basic density, cellulose content and fiber form were investigated for all sample trees at breast height (1.3 m) in seven poplar clones, and at 0 (butt), 5.6, 9.6, 13.6, 17.6, 19.6 and 21.6 m for clone Nanlin-95 and Nanlin-895, respectively, for providing information on variation patterns of wood density, fiber characteristics and holocellulose content within trees and among clones. The results showed that significant variations about wood density, cellulose content, fiber diameter and the ratio of fiber length to diameter existed among poplar clones examined. Variance analysis indicated that there were significant differences in wood basic density, fiber length, fiber diameter and cellulose content among the growth rings, which had an increasing tendency along the direction from pith to bark. The significant differences also existed in wood basic density, fiber length and fiber diameter at different tree height. The mean wood basic density had a general increase trend with increasing height of trees and the lowest was found at the base, while fiber length and fiber diameter had a general decline pattern with increasing height of trees and the biggest value was observed at the height of 5.6 m. Regression analysis indicated that the relationship between examined wood properties and growth ring number (cambial age), and the relationship between examined wood properties and tree height can be described by polynomial functions.
文摘With the aim of creating biodegradable materials for medical devices clinical appointments with high hemocompatibility we have developed a new polymer product.The basis of this product is plasticized by polyethylene glycol bacterial copolymer of hydroxybutyrate and oxovalerate. A well-known antitbrombotic supplement--acetylsalicylic acid has been added to improve hemocompatibility in the polymer. The results of our studies showed a controlled prolonged separation of acetylsalicylic acid from polymeric material in the blood. We studied in vitro the dynamics of liberation of acetylsalicylic acid from polymeric coatings. It was shown that the concentration of polyethylene glycol and the thickness of the polymer layer can affect the rate of diffusion of acetylsalicylic acid from polymer films.
文摘Computer simulation was carried out on fiber length and width for plantation-grown Chinesewhite poplar (Populus tomentosa Carr. clone) and plantation-grown poplar I-72 (P. x eurumericana (Dode)Guiner cv.). Skewness and kurtosis of measured results exhibited that distributions of the fiber length andwidth departured from normal distribution. Three-parameter Weibull density function was used in thisinvestigation and the corresponding program was written with Turbo C. The results showed that profiles ofsimulated length and width histograms were similar to ones of measured histograms, and that there was apretty good agreement between simulated and measured means of fiber length and width. There was a littleinfluence on the simulated means from seed used in random number generator and number of simulatedvariables. That indicated that the simulation was steady when the seed and the number were altered. Differenthistograms can be obtained with different values of the location, the shape, and the scale parameter correspondingto different values of the minimum, the mean, and the standard deviation for fiber length and width. Thesimulation presented here can be used as a tool for the studies on the variations in fiber morphology.
文摘In order to study the influence of wood microstructure on wood dyeing, eleven parameters of wood microstructure and 5 parameters of wood dyeing effects for 34 pieces of wood boards from 5 trees of Chinese white poplar (Populus tomentosa) were determined and the multiple regression analysis between the factors of wood microstructures and the parameters of wood dyeing effects were made. The regression results show that each variable of wood dyeing effects has higher relationship with wood microstructures, and multiple correlation coefficients between each variable of wood dyeing effects and wood microstructures are 0.483 6~0.799 8. The main factors of wood microstructures influencing wood dyeing of Chinese white poplar are proportion of wood ray, proportion of vessel and proportion of wood fiber according to comparing the standardized regression coefficients of multiple regression equation.
文摘The drying characteristic was studied for plantation wood of Chinese fir and poplar, which are typical plantation wood of southern and northern part of China, respectively. Through 100-degree-method the drying characteristic and basic drying condition were gotten, then drying schedule was developed for practical drying, the results showed that the drying schedule is suitable for Chinese fir and poplar plantation lumber, but shrinkage is large. The recommendation was made that enough dead weight is needed to decrease shrinkage in drying process. The drying quality of the two species of lumber is good in conventional drying method.
