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Export Competitiveness and Sustainable Development of the Ukrainian Timber Industry
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作者 Anastasiia Shapiro 《Open Journal of Applied Sciences》 2024年第10期2777-2789,共13页
This paper conducts a comprehensive analysis of the export dynamics within the Ukrainian timber industry, emphasizing its pivotal role in the national economy. The study begins by outlining the research objectives, co... This paper conducts a comprehensive analysis of the export dynamics within the Ukrainian timber industry, emphasizing its pivotal role in the national economy. The study begins by outlining the research objectives, context, and innovative methodologies, setting the stage for a deep dive into the theoretical underpinnings of sustainable and competitive trade. It explores Ukraine’s rich forest biodiversity across varied vegetation zones and its geopolitical significance. Detailed evaluations of forest resource management, policy frameworks, and institutional support form the core of the analysis. Challenges such as imbalanced export structures and legal inconsistencies are critically examined. The research employs trade gravity models and competitive indicators like the Revealed Comparative Advantage (RCA) and Market Share (MS) to assess factors influencing exports and to forecast potential growth areas. The findings inform strategic recommendations aimed at enhancing export capacity through market diversification, brand development, and legal stability. The conclusion highlights the need for strategic interventions to harness Ukraine’s timber resources sustainably, balancing economic gains with environmental stewardship. 展开更多
关键词 Ukrainian Timber Industry Export Dynamics Export Competitiveness Sustainable Trade Forest Resource Management
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Douglas-fi r(Pseudotsuga menziesii(Mirb.)Franco)in Europe:an overview of management practices
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作者 Valeriu-Norocel Nicolescu William LMason +17 位作者 Jean-Charles Bastien Torsten Vor Krasimira Petkova Vilém Podrázský Martina Đodan Sanja Perić Nicola La Porta Robert Brus Siniša Andrašev Martin Slávik Juraj Modranský Michal Pástor Károly Rédei Branislav Cvjetkovic Ahmet Sivacioğlu Vasyl Lavnyy Cornelia Buzatu-Goanță Gheorghe Mihăilescu 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第4期871-888,共18页
Douglas-fir(Pseudotsuga menziesii(Mirb.)Franco),one of the most commercially important tree species in western North America and one of the most valuable timber trees worldwide,was introduced to Europe in 1827.It beca... Douglas-fir(Pseudotsuga menziesii(Mirb.)Franco),one of the most commercially important tree species in western North America and one of the most valuable timber trees worldwide,was introduced to Europe in 1827.It became a major species for aff orestation in Western Europe after WWII,currently grows in 35 countries on over 0.83 million ha and is one of the most widespread nonnative tree species across the continent.A lower sensitivity to drought makes Douglas-fi r a potential alternative to the more drought-sensitive Norway spruce so its importance in Europe is expected to increase in the future.It is one of the fastest growing conifer species cultivated in Europe,with the largest reported dimensions of 2.3 m in diameter and 67.5 m in height.Pure stands have high productivity(up to 20 m 3 ha−1 a−1)and production(over 1000 m 3 ha−1).The species is generally regenerated by planting(initial stocking density from less than 1000 seedlings ha−1 to more than 4000 ha−1),using seedlings of European provenance derived from seed orchards or certifi ed seed stands.As the range of end-uses of its wood is very wide,the rotation period of Douglas-fi r is highly variable and ranges between 40 and 120 years.When the production of large-sized,knotfree timber is targeted,thinnings are always coupled with pruning up to 6 m.There is an increasing interest in growing Douglas-fi r in mixtures and managing stands through close-to-nature silviculture,but the species’intermediate shade tolerance means that it is best managed through group selection or shelterwood systems. 展开更多
关键词 Douglas-fi r Ecological requirements Growth and yield Timber Climate change
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Experimental Investigation on the Strength and Ductility Performance of Steel-Timber-Steel Joints with Screw and Steel-Tube Fasteners
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作者 Huifeng Yang Mingwang Wu +3 位作者 Rixin Gu Hang Cao Kai Xiao Benkai Shi 《Journal of Renewable Materials》 EI 2023年第12期4175-4195,共21页
This article presents experimental results of steel-timber-steel(STS)joints loaded parallel to grain.Eight groups of specimens were designed,and tensile tests were performed.The fastener types and fastener numbers wer... This article presents experimental results of steel-timber-steel(STS)joints loaded parallel to grain.Eight groups of specimens were designed,and tensile tests were performed.The fastener types and fastener numbers were considered to evaluate the tensile strengths and ductility performances of the STS joints.The screws with 6 mm diameter and the innovative steel-tubes with 18 mm diameter were adopted as connecting fasteners.The experimental results were discussed in terms of yielding and ultimate strengths,slip stiffness,and ductility factors.The ductility classification and failure mechanisms of each group of specimens were analyzed.It was demonstrated that the STS joint with large diameter steel-tubes showed acceptable ductility,which was close to the ductility of the STS joint with small diameter screws,thanks to the hollow structure of the steel-tube.The theoretical strengths of various failure modes for the joints with small diameter screws or large diameter steel-tubes were calculated and compared with the experimental results.The ductile performance of the STS joint was discussed by comparing the theoretical strengths of various failure modes.The effective number of the STS joint with multifasteners was also analyzed by considering the failure mechanisms in aspects of tensile strength and slip stiffness. 展开更多
关键词 Steel-timber-steel joint SCREW steel-tube DUCTILITY experimental investigation timber structure
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An Experimental Study of Composite Columns Filled with Eucalyptus nitens Timber under Axial Compression
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作者 Yingyao Cheng Xudong Chen +2 位作者 Huaming An Huimin Wang Kai Tao 《Journal of Renewable Materials》 SCIE EI 2023年第2期825-836,共12页
Eucalyptus nitens(E.nitens)has been much used for producing paper but also shows promise for structural applications.In this study,static compressive tests were undertaken to examine its suitability to be used in an i... Eucalyptus nitens(E.nitens)has been much used for producing paper but also shows promise for structural applications.In this study,static compressive tests were undertaken to examine its suitability to be used in an innovative composite column.The composite column was comprised of a rectangular steel tube with E.nitens timber infill.The nonlinear compressive behaviour of the composite column filled with E.nitens wood for both dry and wet conditions was examined.The same tests on rectangular steel tubes and bare dry and wet E.nitens samples were also undertaken as a comparison.For samples with different conditions,the ultimate capacity was evaluated and the effect of each condition on the compressive behaviour of the composite column was clarified.The steel tubes showed greater ductile behaviour,and more ductility was found in the wet samples.The steel tubes with E.nitens timber infill samples exhibited a greater linear elastic range connected with higher maximum loads,while the bare timber samples could support only lower maximum loads.The results from this research were promising for the use of rectangular steel tubes with E.nitens timber infill in structural applications. 展开更多
关键词 Hollow steel tubes EUCALYPTUS high moisture content composite column with timber infill compression
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Three-dimensional inversion of knot defects recognition in timber cutting
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作者 Yizhuo Zhang Dapeng Jiang +1 位作者 Zebing Zhang Jinhao Chen 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第4期1145-1152,共8页
The comprehensive utilization of wood is the main goal of log cutting,but knot defects increase the diffi-culty of rationally optimizing cutting.Due to the lack of real shape data of knot defects in logs,it is diffi c... The comprehensive utilization of wood is the main goal of log cutting,but knot defects increase the diffi-culty of rationally optimizing cutting.Due to the lack of real shape data of knot defects in logs,it is diffi cult for detection methods to establish a correlation between signal and defect morphology.An image-processing method is proposed for knot inversion based on distance regularized level set segmentation(DRLSE)and spatial vertex clustering,and with the inversion of the defects existing relative board position in the log,an inversion model of the knot defect is established.First,the defect edges of the top and bottom images of the boards are extracted by DRLSE and ellipse fi tting,and the major axes of the ellipses made coplanar by angle correction;second,the coordinate points of the top and bottom ellipse edges are extracted to form a spatial straight line;third,to solve the intersection dispersion of spatial straight lines and the major axis plane,K-medoids clustering is used to locate the vertex.Finally,with the vertex and the large ellipse,a 3D cone model is constructed which can be used to invert the shape of knots in the board.The experiment was conducted on ten defective larch boards,and the experimental results showed that this method can accurately invert the shapes of defects in solid wood boards with the advantages of low cost and easy operation. 展开更多
关键词 Timber knot inversion Distance regularized level set segmentation(DRLSE) Ellipse fi tting K-medoids cluster
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In Situ Generation of Copper Nanoparticles in Heat-Treated Copper-Containing Masson’s Pine as a Preservative Process for Sawn Timber
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作者 Minting Lai Guijun Xie +2 位作者 Wanju Li Lamei Li Yongjian Cao 《Journal of Renewable Materials》 SCIE EI 2023年第6期2665-2678,共14页
Heat-treated wood has good dimensional stability,durability,and color,but its susceptibility to fungal growth affects its commercial value.In this study,lumber harvested from mature Masson’s pine(Pinus massoniana Lam... Heat-treated wood has good dimensional stability,durability,and color,but its susceptibility to fungal growth affects its commercial value.In this study,lumber harvested from mature Masson’s pine(Pinus massoniana Lamb.)was vacuum impregnated with a basic copper salt solution(copper hydroxide,diethanolamine,and polyethylene glycol 200)prior to heat-treatment at 220℃ for 3 h.Antifungal properties,surface chemistry,crystal structure and sugar contents were tested,compared with heat treatment alone.The results showed that the samples treated by heating without copper salt treatment showed poor suppression of fungal growth,the copperimpregnated heat-treated wood suppressed(100%)the growth of Botryodiplodia theobromae Pat.,Aspergillus niger V.Tiegh.,Penicillium citrinum Thom,and Trichoderma viride Pers.The combined results of X-ray photoelectron spectroscopy,X-ray diffraction and sugars analysis suggested that fungal inhibition by the heat-treated copper-bearing Masson’s pine was mainly due to the reduction of the metal salt by PEG200 at high temperature to generate copper nanoparticles.In addition,the reduced sugar content of the treated timber,and hence the nutrient substrate for spoilage microbes,reduced in the presence of the metal salts at high-temperature.This study has demonstrated an effective method of increasing low-grade wood’s utility and commercial value. 展开更多
关键词 Heat treatment Masson’s pine sawn timber inhibition of fungal growth copper nanoparticles
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Verification of Depth Adjustment Factor in Eurocode 5 for Tropical Hardwood Timbers
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作者 Adnie Baharin Muhammad Amirul Akmal Rosli +4 位作者 Norshariza Mohamad Bhkari Lum Wei Chen Anis Azmi Muhammad Shaiful Nordin Zakiah Ahmad 《Journal of Renewable Materials》 EI 2023年第9期3533-3546,共14页
The depth adjustment factor for bending strength stated in Eurocode 5(EC5)is only applicable to timbers having a characteristic density below 700 kg/m^(3).However,most Malaysian timbers are hardwood,some with a charac... The depth adjustment factor for bending strength stated in Eurocode 5(EC5)is only applicable to timbers having a characteristic density below 700 kg/m^(3).However,most Malaysian timbers are hardwood,some with a characteristic density reaching above 700 kg/m^(3).Therefore,the objective of this study was to examine whether the depth adjustment factor stipulated in EC5 is valid for Malaysian hardwood timbers.Six timber species were selected for this study,namely Kapur(Dryobalanops C.F.Gaertn.),Kempas(Koompassia Maingay ex Benth.),Keruing(Dipterocarpus C.F.Gaertn.),Light red meranti(Shorea Roxb.ex C.F.Gaertn.),Geronggang(Cratoxylum Blume)and Balau(Shorea Roxb.ex C.F.Gaertn.).The determination of bending strength and characteristic density was conducted according to BS EN 408:2010 and BS EN 384:2016,respectively.A graph for mean bending strength vs.(150/h)was plotted for each timber species.The power function was selected to analyze the relationship between the two variables.The power of the regression equations varied depending on the characteristic density of the timber species.For species with a characteristic density below 700 kg/m^(3),such as Kapur,Keruing,and Light red meranti,the power was between 0.16 to 0.17.In contrast,for species having a characteristic density above 700 kg/m^(3),namely Kempas and Balau,the power was higher at 0.23 and 0.24,respectively.Geronggang was an exception to this pattern.These values are close to the depth adjustment factor given in EC5,which is 0.2.Based on the results,it can be suggested that the adjustment factor of 0.2 is also applicable to Malaysian hardwood timbers with a characteristic density above 700 kg/m^(3). 展开更多
关键词 Depth adjustment factor Malaysian hardwood timber bending strength Eurocode 5
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Determination of the Properties of Some Selected Timber Species for Structural Application
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作者 Asimiyu Amobi Oyediran Catherine Mayowa Ikumapayi Babatola Olufemi 《World Journal of Engineering and Technology》 2023年第2期319-334,共16页
One of the alternative sustainable and green construction materials to concrete is timber. Timber is of numerous varieties, and this acts as a barrier to the extent of its usage, especially in structural application. ... One of the alternative sustainable and green construction materials to concrete is timber. Timber is of numerous varieties, and this acts as a barrier to the extent of its usage, especially in structural application. Despite many researches on wood’s mechanical and physical properties, only a few are geared toward the structural application of wood. The present work investigated the mechanical properties of five timber species;Gmelina arborea, Tectona grandis (Teak), Terminalia superba (Afara), Ayin (Anogeissus leiocarpus), and Acacia (Robinia pseudoacacia), to determine their suitability for constructing long-span roof trusses. These are available in the South Western part of Nigeria. Their mechanical properties;bending strength, compressive strength, shear strength, tensile strength, Modulus of Elasticity (MOE), Modulus of Rupture (MOR), and density, were determined in the laboratory. The results obtained showed that all the timber types, except Terminalia superba (Afara), have higher values of mechanical properties than the values that are obtainable for classes of strength D30 to class D70 in the British Code of Practice. It means these species are of higher quality than the stipulated strength classes in the British code. The results also show that the order of relevance of the species for structural design (or work) is Acacia (Robinia pseudoacacia), Ayin (Anogeissus leiocarpus), Gmelina Arborea, and Tectona grandis (Teak). Terminalia superba (Afara) is not recommended for structural works. 展开更多
关键词 Timber Wood Species Bending Strength Compression Mechanical Properties
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MYBL1在肾透明细胞癌组织中表达及与其预后相关性分析
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作者 周成炜 王桦 +1 位作者 程玲 孔嘉欣 《实用癌症杂志》 2023年第8期1245-1249,共5页
目的 探讨MYBL1在肾透明细胞癌中表达及与其预后的相关性。方法 通过TCGA数据库获取肾透明细胞癌患者临床资料,卡方检验分析MYBL1表达在肾透明细胞癌中相关因素,R软件分析MYBL1在肾透明细胞与癌旁组织表达差异;受试者工作曲线特征(ROC)... 目的 探讨MYBL1在肾透明细胞癌中表达及与其预后的相关性。方法 通过TCGA数据库获取肾透明细胞癌患者临床资料,卡方检验分析MYBL1表达在肾透明细胞癌中相关因素,R软件分析MYBL1在肾透明细胞与癌旁组织表达差异;受试者工作曲线特征(ROC)分析MYBL1诊断肾透明细胞癌准确度。LimkedOmic数据库进行GO/KEEG分析;TIMER数据库评估肾透明细胞癌中MYBL1表达与免疫细胞浸润分析。结果 MYBL1表达与性别(P=0.008)、肿瘤分级(P=0.001)、T分期(P=0.02)、M分期(P=0.003)显著相关,与种族、年龄、N分期无显著相关。肾透明系细胞癌组织MYBL1表达水平明显高于癌旁组织,MYBL1低表达组总生存期及疾病无进展期均优于高表达组(P<0.01),ROC曲线结果显示:MYBL1具有较高的诊断准确性0.926,可信区间为(0.89~0.926);GO/KEE通路分析显示MYBL基因参与细胞器分裂、细胞核分裂、染色体分离以及ATP酶活性和偶联、微管运动等多种细胞周期活动。MYBL1表达与B细胞(cor=0.209)、CD4+T细胞(cor=0.178)、CD8+T细胞(cor=0.388)、巨噬细胞(cor=0.331)、中性粒细胞(cor=0.484)、树突状细胞(cor=0.331)等呈正相关,P均<0.01。结论 MYBL1基因表达水平与肾透明细胞癌总体预后相关,可成为肾透明细胞癌新型诊断、预后标志物,有望为治疗提供新的靶点。 展开更多
关键词 MYBL1 肾透明细胞癌 TCGA数据库 TIMBER数据库
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Novel Proposal of Bio-based Sewing Timber Joint:Learning from Diatoms
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作者 Mauricio Díaz Valdés Melisa Gálvez Bohórquez 《Journal of Building Material Science》 2023年第1期1-8,共8页
The twenty-first century is one of the most complex in the history of humanity,mainly due to the ecological crisis it is going through.The construction sector generates about 40%of CO2 emissions into the environment;t... The twenty-first century is one of the most complex in the history of humanity,mainly due to the ecological crisis it is going through.The construction sector generates about 40%of CO2 emissions into the environment;the foregoing should motivate this sector to seek new alternatives to develop new building practices.Taking these current needs into account,this document classifies and presents a multidisciplinary solution that integrates biology,engineering and architecture to develop a new and innovative lightweight timber structure;it divides with a main structure made of timber and an innovative joint system made of bio-polymers connecting all the panels.Through the study of diatoms,it was able to analyze the bio-morphology of the structure,joints and in particular the geometry since they were the inspiration for the design of this structure that presents an innovative and novel design of structural optimization.Through parametric design and digital fabrication,it was able to create a complex geometry that obtains excellent structural behavior.This research discusses and explores how materials,geometry led to the optimization of a structure and how new structures can arise,thanks to biology new solutions can be obtained that are completely sustainable,being a clear example of how to combat the effects of the climate change and in a precise way it highlights the advantages of the bio-design in the architectural design. 展开更多
关键词 DIATOMS Timber joinery Computational method Topology optimization Biomimetics BIO-INSPIRED Lightweight structure
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Use of Irregular Wood Components to Design Non-Standard Structures
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作者 Jean Claude Bignon 《Journal of Civil Engineering and Architecture》 2023年第6期307-313,共7页
This project deals with architecture and engineering involved in the process of architectural design.Based on native irregular components,it aims at developing an innovative approach in the conception and rationalizat... This project deals with architecture and engineering involved in the process of architectural design.Based on native irregular components,it aims at developing an innovative approach in the conception and rationalization of non-standard structures.Contemporary architecture and its non-classical structures require the design of customized pieces.This process which is highly energy and resources consumptive does not always take into account the inherent material properties.This project develops a way of optimizing,in architectural structures,the use of native wood pieces that are not industrially transformed(e.g.boughs)or of reused pieces of carpentry.As a consequence,the ecological footprint of the structures would be reduced. 展开更多
关键词 Architecture timber structure native irregular resources environmental foot-print
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Application of single neuron adaptive PID controller during the process of timber drying 被引量:4
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作者 张冬妍 刘亚秋 曹军 《Journal of Forestry Research》 SCIE CAS CSCD 2003年第3期244-248,共5页
The paper presents a method of using single neuron adaptive PID control for adjusting system or servo system to implement timber drying process control, which combines the thought of parameter adaptive PID control and... The paper presents a method of using single neuron adaptive PID control for adjusting system or servo system to implement timber drying process control, which combines the thought of parameter adaptive PID control and the character of neural network on exactly describing nonlinear and uncertainty dynamic process organically. The method implements functions of adaptive and self-learning by adjusting weighting parameters. Adaptive neural network can make some output trail given hoping value to decouple in static state. The simulation result indicates the validity, veracity and robustness of the method used in the timber drying process 展开更多
关键词 Process control Timber drying Single neuron Adaptive control PID control
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Mechanical properties of monodirectional Gutou mortise-tenon joints of the traditional timber buildings in the Yangtze River region 被引量:6
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作者 淳庆 韩宜丹 孟哲 《Journal of Southeast University(English Edition)》 EI CAS 2016年第4期457-463,共7页
The mechanical properties of the monodirectional Gutou mortise-tenon joints of the ancient Chinese traditional timber buildings in the Yangtze River region were studied using the experimental method. Three monodirecti... The mechanical properties of the monodirectional Gutou mortise-tenon joints of the ancient Chinese traditional timber buildings in the Yangtze River region were studied using the experimental method. Three monodirectional Gutou mortise-tenon joints were designed according to the actual configurations. The failure modes,the hysteretic curves,the skeleton curves, the rotation rigidities, and the energy dissipation capacity of this type of mortise-tenon joints under the low cyclic reversed loading were obtained. The results show that the hysteretic curves of the monodirectional Gutou mortise-tenon joints appear to be Z shape and have obvious pinch effects. During the process of the test,these mortisetenon joints pass orderly through the elastic stage,the yield stage and the failure stage. The energy dissipation capacity of these mortise-tenon joints generally decreases with the increase in the rotation angle. The equivalent viscous damping coefficients of the monodirectional Gutou mortise-tenon joints are between 0. 161 and 0. 193. The results can provide the theoretical base for the computing analysis and repair design of Chinese traditional timber buildings in the Yangtze River region. 展开更多
关键词 traditional timber building monodirectional Gutou mortise-tenon joint mechanical property energy dissipation capacity
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Plantation future of bamboo in China 被引量:13
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作者 李兆华 小林干夫 《Journal of Forestry Research》 SCIE CAS CSCD 2004年第3期233-242,共10页
In the past, utilization of bamboo resources in China has been traditionally dominated by direct consumption of local farmers as minor forest products with weak linkage with market. In recent years, the over-supply of... In the past, utilization of bamboo resources in China has been traditionally dominated by direct consumption of local farmers as minor forest products with weak linkage with market. In recent years, the over-supply of grains and rapid degradation of agricultural environment call for alternative crops that can be developed through integrating the environmental plantation with the market demands. Closely associated with forestry and agriculture, bamboo is able to deal with the new challenges which Chinas agriculture is facing. Of 534 documented bamboo species in China, 153 species produce edible-shoots and of which 56 species are recommended for agricultural plantation; 139 species provide timbers and of which 58 species recommended; 116 species can be splited as good strips for weaving and of which 22 species recommended; 88 species are considered as garden bamboos and of which 34 species recommended; 45 species are able to produce paper pulp and of which 18 species recommended. 展开更多
关键词 AGRICULTURE BAMBOO Edible shoot Timber WEAVING China
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Investigation on the Situation of Biological Hazards of Ancient Architecture in Tianshui City 被引量:1
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作者 闫晨曦 黄伟 《Journal of Landscape Research》 2009年第7期77-80,共4页
Based on inspecting and investigating the situation of biological hazards of ancient architecture such as north-south building,Fuxi temple and Yuquan Temple,the disease kinds,their damaging ranges and hazard degrees w... Based on inspecting and investigating the situation of biological hazards of ancient architecture such as north-south building,Fuxi temple and Yuquan Temple,the disease kinds,their damaging ranges and hazard degrees were recorded.The results showed that timber structures had some problems such as colored drawing of purlin post,Fang,bucket arches had fallen off;rot,infesting,color spot,sediments on the surface,rupture,warp,breeding plant etc. 展开更多
关键词 ANCIENT ARCHITECTURE Timber structure BIOLOGICAL HAZARD
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Structural Carpentry in Qing Dynasty-A Framework for the Hierarchically Modularized Chinese Timber Structural Design 被引量:1
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作者 龚清宇 《Transactions of Tianjin University》 EI CAS 2002年第1期16-21,共6页
This article, by using mathematical expressions, offers a scientific framework for understanding how the grading system of Qing′s structural carpentry determines the design and construction in the grand style timber... This article, by using mathematical expressions, offers a scientific framework for understanding how the grading system of Qing′s structural carpentry determines the design and construction in the grand style timber architecture.The Qing′s grand style timber structure, which is ready for prefabrication and assembly, is extremely hierarchical oriented and significantly standardized. The general procedure in designing a grand style timber structure is to start with the grade that defines the basic module (dou kou); next comes with the number of bracket set (cuan), the number of longitudinal bays and the number of purlins which affect its plan and cross section; thirdly choose a roof type that determines its longitudinal section and the facade as well. A series of formulae are conducted to help depict the layout, cross sectional roof curvature and special longitudinal treatments in 4 sloped and 9 spined roofs respectively. 展开更多
关键词 structural carpentry mathematical expression grand style Qing Dynasty modular system Chinese timber structural design
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Forestland prediction of China based on forest ecosystem services for the first half of 21st century
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作者 董仁才 陈春娣 +1 位作者 邓红兵 赵景柱 《Journal of Forestry Research》 SCIE CAS CSCD 2008年第3期181-186,共6页
A new model was developed to predict forestland demand of China during the years of 2010-2050 in terms of the concept of forest ecosystem services. On the basis of the relationship between forest ecosystem services an... A new model was developed to predict forestland demand of China during the years of 2010-2050 in terms of the concept of forest ecosystem services. On the basis of the relationship between forest ecosystem services and classified forest management, we hypothesized that the ecological-forest provides ecological services, whereas commercial-forest supplies wood and timber production, and the influences of the growth of population, social-economic development target, forest management methods and the technology changes on forest resources were also taken into account. The prediction reveals that the demand of total forestland of China will be 244.8, 261.2 and 362.2 million ha by the year 2010, 2020 and 2050, respectively. The results demonstrated that China will be confronted with a shortage of forest resources, especially with lack of ecological-oriented forests, in the future. It is suggested that sustainable management of forest resources must be reinforced and more attention should be drown no enhancing the service function of forest ecosystem. 展开更多
关键词 forest resources forest ecosystem services forestland prediction commercial forest ecological forest timber demand ecological demand
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Analysis of moisture diffusivity of larch timber during convective drying condition by using Crank's method and Dincer's method 被引量:4
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作者 ZHAN Jian-feng GU Ji-you CAI Ying-chun 《Journal of Forestry Research》 SCIE CAS CSCD 2007年第3期199-202,共4页
Two analytical procedures (Crank's method and Dincer's method) for porous solid materials were reevaluated and used to determine moisture diffusion coefficients and moisture transfer coefficients for larch lumber ... Two analytical procedures (Crank's method and Dincer's method) for porous solid materials were reevaluated and used to determine moisture diffusion coefficients and moisture transfer coefficients for larch lumber subjected to drying. A diffusion-like equation was used to describe drying process data. The lumber was idealized in the modeling as infinite plates. The moisture transport process inside the board was assumed to be one-dimensional. The macroscopic drying kinetics curves of larch timber at particular conditions were determined experimentally. Based on these data, calculation for both the moisture diffusion coefficients and moisture transfer coefficients by the Dincer's analytical procedure were made. The dynamic moisture diffusion coefficients by the traditional Crank's method were calculated. In general, diffusion coefficients calculated by the Dincer's method were all higher than those by Crank's method. These results could be due to the differences between two analytical methods and also different characteristics between solid moisture diffusion process and heat transfer process. Therefore the analysis and solution procedures of moisture diffusion differential equations need to be adapted in the future. With drying temperature's increasing moisture diffusion coefficient (D) and moisture transfer coefficient (k) increases accordingly. Also the relationships between diffusion coefficients and temperature as well as material moisture contents were analyzed by using Arrhenius equation and bound water transport theory. 展开更多
关键词 Larch timber Wood dry Moisture diffusion coefficient Moisture transfer coefficient Mathematical model
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Selection of superior families of Pinus massoniana in southern China for large-diameter construction timber 被引量:4
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作者 Zhangqi Yang Hui Xia +2 位作者 Jianhui Tan Yuanheng Feng Yongli Huang 《Journal of Forestry Research》 SCIE CAS CSCD 2020年第2期475-484,共10页
This study addresses the increasing demand for large-diameter production timber,and considers the time and space variability of half-sib families of Pinus massoniana.Height,diameter at breast height(DBH)and timber vol... This study addresses the increasing demand for large-diameter production timber,and considers the time and space variability of half-sib families of Pinus massoniana.Height,diameter at breast height(DBH)and timber volume of 440 open-pollinated half-sib progeny families were investigated in 14 progeny trials in different years and production regions.An evaluation of the genetic variation of all half-sib families was carried out during the sustainable rapid growth period and individual volumes were characterized as a major index.ANOVA analysis showed that there was considerable variance in the growth traits of most families in different years and on different sites.The variations caused by temporal and spatial changes of the mating system required three selection methods for analysis.The results show that there were differences among the heritabilities of different growth traits by different halfsib progenies.Average heritability values of height,DBH and volume were 0.33,0.34 and 0.36,respectively.Fortyfive superior families were selected in every progeny test,12 were selected in progeny trials by different years and five in different habitat progeny trials.Three superior families(Gui GC553A,Gui GC414A and Gui GC431A)were selected,although in different years and production regions.The genetic gains of timber volume of these selected r families ranged from 1.20 to 47.00%,which could provide a foundation for superior wood property selection and serve as material for seed improvement and extension in surrounding areas. 展开更多
关键词 Pinus massoniana Open-pollinated progeny Large-diameter timber Superior family selection Mating system
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Economics of the plant species used in homestead agroforestry on an offshore Sandwip Island of Chittagong District, Bangladesh 被引量:3
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作者 R. U. Momen S. M. S. Huda +1 位作者 M. K. Hossain B. M. Khan 《Journal of Forestry Research》 SCIE CAS CSCD 2006年第4期285-288,共4页
This study was performed in five villages of Sandwip Upazila, Chittagong district with a view to identify the tree resources, utilization pattern and economic return of major fruit and timber tree species. Information... This study was performed in five villages of Sandwip Upazila, Chittagong district with a view to identify the tree resources, utilization pattern and economic return of major fruit and timber tree species. Information collected from a total of 60 households ranging from marginal, small, medium and large categories. Number of plant species increased with the increase of homestead area. A total of 33 plant species were recorded from the homegarden, of which 19 were fruit and 14 were timber tree species. Considerable number of vegetables was also planted under the shade of the homestead trees. The investment analysis showed that average benefit-cost ratios were greater than one, net present values were positive and internal rate of returns were more than 10%. Long term investment on horticulture and timber tree species is highly profitable if species like Artocarpus heterophyllus, Cocos nucifera, Tectona grandis and Swietenia macrophylla are planted. 展开更多
关键词 AGROFORESTRY Fruit tree Timber tree ECONOMICS HOMEGARDEN Sandwip
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