To determine the distribution of stem decay in the beech stands of Azerbaijan, we sought to identify the species, number, and height of attachment of fruiting bodies;the extent of decay in tree trunks growing under di...To determine the distribution of stem decay in the beech stands of Azerbaijan, we sought to identify the species, number, and height of attachment of fruiting bodies;the extent of decay in tree trunks growing under different conditions;and its influence on the trees’ commercial wood. The research was conducted on three farms representing the most common forest types of the Greater Caucasus within Azerbaijan. Examination of the presence of fruiting bodies in the tree trunk revealed that stem decay is the most common infection in beech (Fagus orientalis) stands, especially in fresh, moist areas, with less infection under dry growing conditions. In this work, the length, diameter, and volume of decay were studied by infecting the trunks of 93 model trees affected with mushrooms in 1–4 m cuttings. Our results showed that as the age of the stand increased, extent, diameter, and volume of decay increased significantly: the extent of decay from 1.47 to 6.43 m;the diameter of the decay from 8.15 to 32.7 cm;and the volume of decay from 2.5 to 13.2%. The relationship between age and the specified indicators is presented graphically. Using data obtained from the same sample of trees, we determined the expected and actual yield of commercial wood by age class. We determined that stem decay in beech stands leads to a decrease in the yield of commercial wood on average from 25.1% in the middle-aged to 14.8% in overmature plantations, respectively, with an estimated yield of 40.8–62.7%. Here we present mathematical models of the output of commercial wood from the infected part of the stands by age classes with the use of average data on the extent of decay in model trees.展开更多
Figured black walnut lumber is a specialty wood product that commands a high price for manufacturing fine furniture and interior paneling. Two common figured grain patterns occur in walnut;they are known as “fiddle-b...Figured black walnut lumber is a specialty wood product that commands a high price for manufacturing fine furniture and interior paneling. Two common figured grain patterns occur in walnut;they are known as “fiddle-back” or “curly” grain, depending on the number of horizontal lines visible in the grain of the finished wood. The occurrence of figured walnut in nature is rare and unpredictable. Trees that have consistent figured patterns throughout the log are of exceptional value. Conversely, trees with partial or spotty figured patterns are considered defective and are reduced in value. Conventional breeding of seedlings, or cloning figured trees by grafting, are possible methods to propagate figured wood in walnut. The value of such material, however, will depend on figure being expressed predictably. For breeding to succeed, the trait of interest must be genetic and heritable. For clonal propagation to be effective, the trait must be reproduced true-to-type. In this study, we evaluate the grain pattern of both grafted and seedling walnut from several highly figured wild selections. Logs from grafted trees of three clones propagated in the 1970s in Kansas were evaluated. Only one log from one clone showed some figure in its lumber. Ten-year-old seedlings from the figured walnut clone “Lamb” were grown and cut in Indiana and evaluated for figured grain, and none showed any sign of figured grain developing. Our conclusion is that figured grain in black walnut does not propagate true-to-type through grafting or by growing open-pollinated seed. Although evidence of some genetic control of figure was found, environmental and other factors appear to play a greater role.展开更多
The approximate analytic bound state solutions of the Klein-Gordon equation with equal scalar and vector exponential-type potentials including the centrifugal potential term are obtained for any arbitrary orbital quan...The approximate analytic bound state solutions of the Klein-Gordon equation with equal scalar and vector exponential-type potentials including the centrifugal potential term are obtained for any arbitrary orbital quantum number l and dimensional space D. The relativistic/non-relativistic energy spectrum formula and the corresponding un-normalized radial wave functions, expressed in terms of the Jacobi polynomials and or the generalized hypergeometric functions have been obtained. A short-cut of the Nikiforov-Uvarov (NU) method is used in the solution. A unified treatment of the Eckart, Rosen-Morse, Hulthén and Woods-Saxon potential models can be easily derived from our general solution. The present calculations are found to be identical with those ones appearing in the literature. Further, based on the PT-symmetry, the bound state solutions of the trigonometric Rosen-Morse potential can be easily obtained.展开更多
基金‘‘Azerbaijan University of Architecture and Construction’’ and Ministry of Ecology and Natural Resources
文摘To determine the distribution of stem decay in the beech stands of Azerbaijan, we sought to identify the species, number, and height of attachment of fruiting bodies;the extent of decay in tree trunks growing under different conditions;and its influence on the trees’ commercial wood. The research was conducted on three farms representing the most common forest types of the Greater Caucasus within Azerbaijan. Examination of the presence of fruiting bodies in the tree trunk revealed that stem decay is the most common infection in beech (Fagus orientalis) stands, especially in fresh, moist areas, with less infection under dry growing conditions. In this work, the length, diameter, and volume of decay were studied by infecting the trunks of 93 model trees affected with mushrooms in 1–4 m cuttings. Our results showed that as the age of the stand increased, extent, diameter, and volume of decay increased significantly: the extent of decay from 1.47 to 6.43 m;the diameter of the decay from 8.15 to 32.7 cm;and the volume of decay from 2.5 to 13.2%. The relationship between age and the specified indicators is presented graphically. Using data obtained from the same sample of trees, we determined the expected and actual yield of commercial wood by age class. We determined that stem decay in beech stands leads to a decrease in the yield of commercial wood on average from 25.1% in the middle-aged to 14.8% in overmature plantations, respectively, with an estimated yield of 40.8–62.7%. Here we present mathematical models of the output of commercial wood from the infected part of the stands by age classes with the use of average data on the extent of decay in model trees.
文摘Figured black walnut lumber is a specialty wood product that commands a high price for manufacturing fine furniture and interior paneling. Two common figured grain patterns occur in walnut;they are known as “fiddle-back” or “curly” grain, depending on the number of horizontal lines visible in the grain of the finished wood. The occurrence of figured walnut in nature is rare and unpredictable. Trees that have consistent figured patterns throughout the log are of exceptional value. Conversely, trees with partial or spotty figured patterns are considered defective and are reduced in value. Conventional breeding of seedlings, or cloning figured trees by grafting, are possible methods to propagate figured wood in walnut. The value of such material, however, will depend on figure being expressed predictably. For breeding to succeed, the trait of interest must be genetic and heritable. For clonal propagation to be effective, the trait must be reproduced true-to-type. In this study, we evaluate the grain pattern of both grafted and seedling walnut from several highly figured wild selections. Logs from grafted trees of three clones propagated in the 1970s in Kansas were evaluated. Only one log from one clone showed some figure in its lumber. Ten-year-old seedlings from the figured walnut clone “Lamb” were grown and cut in Indiana and evaluated for figured grain, and none showed any sign of figured grain developing. Our conclusion is that figured grain in black walnut does not propagate true-to-type through grafting or by growing open-pollinated seed. Although evidence of some genetic control of figure was found, environmental and other factors appear to play a greater role.
文摘为了分析南方型黑杨生长性状、木材性状对其湿心材形成的影响程度,于2023年11月份,在岳阳市君山区丁字堤南方型黑杨试验林,选取13年生的8个南方型黑杨无性系为研究对象,每个无性系选取6株样株,用9 mm生长锥在树高1.3 m处钻取木样,分别测量木芯长度、湿心材长度,并称量质量;依据试验设计,测定样木的胸径、树高、材积、树液pH、生材含水量、气干材含水量、木材基本密度;运用相关分析法、通径分析法,计算各性状对湿心材比例的直接影响、间接影响、决定系数,分析南方型黑杨无性系生长性状、木材性状的7个性状指标对湿心材比例的影响。结果表明:8个无性系间,湿心材比例、胸径、树高、材积、生材含水量存在极显著差异。树液pH和生材含水量,与湿心材比例存在极显著正相关,气干材含水量与湿心材比例存在显著正相关。通径分析表明,生材含水量(W r)、树液pH、气干材含水量(W a)是影响湿心材比例(R(wh))的重要因子,通过多元回归分析建立3个性状与湿心材比例的多元回归方程R(wh)=-0.995+0.006pH+0.075 W r+0.005 W a;其中,生材含水量对湿心材比例的直接影响(0.522)和单独决定系数大小表明,生材含水量对湿心材比例影响最大。因此,生材含水量大小可以作为选育南方型黑杨低湿心材选育时的评定指标。
文摘The approximate analytic bound state solutions of the Klein-Gordon equation with equal scalar and vector exponential-type potentials including the centrifugal potential term are obtained for any arbitrary orbital quantum number l and dimensional space D. The relativistic/non-relativistic energy spectrum formula and the corresponding un-normalized radial wave functions, expressed in terms of the Jacobi polynomials and or the generalized hypergeometric functions have been obtained. A short-cut of the Nikiforov-Uvarov (NU) method is used in the solution. A unified treatment of the Eckart, Rosen-Morse, Hulthén and Woods-Saxon potential models can be easily derived from our general solution. The present calculations are found to be identical with those ones appearing in the literature. Further, based on the PT-symmetry, the bound state solutions of the trigonometric Rosen-Morse potential can be easily obtained.