The adsorption diffusion coefficients of beech and welded beech were higher than those of pine and welded pine up to 50 % and 40 % RH, respectively. The time to complete half of the fractional change in moisture content ( E ( t ) = 0.5) increased as the moisture content increased. However, the welded wood showed slower adsorption but faster desorption than unwelded wood. All specimens showed faster adsorption than desorption. The welded bond-lines of beech and pine showed greater hysteresis than the unwelded wood from 0 to 55 % relative humidity. The welded wood generally had lower equilibrium moisture contents than the unwelded wood. The objective was to provide deepened knowledge about water sorption of the welded bond-line, which could be used to improve the moisture resistance of welded wood in the future. The aim of this study was to characterize the water sorption in the welded bond-line and to define to which extent it deviates from water sorption of the unwelded wood. The wood–water interactions of welded bond-lines of European beech ( Fagus sylvatica L.) and Scots pine ( Pinus sylvestris L.) were in this paper studied for the first time with dynamic vapour sorption equipment. On-demand quick supply of a large amount of monolignols and HCs can be achieved by the large storage and delivery of MLGs in the growing ginkgo xylem. The deformable G-lignin-HCs-CMFs layer at secondary wall shrinks by dehydration of the swollen gel of HCs-CMFs during differentiation, and contributes posture control of standing tree. (3) At cell corner middle lamella, a pressure-resistant layer of HG-lignin-HCs-CMFs is formed, and allows expansion of new cells in cambium region by elevation of turgor pressure. (2) The d -Glc liberated at lignification site is converted into essential HCs mainly via Golgi apparatus under the influence of diurnally changing turgor pressure, and partly converted in the apoplast. Based on the 13 C-tracer studies of ginkgo xylem formation, a hypothetical scenario for the role of monolignol glucosides (MLGs) in the assembly is proposed as follows: (1) Both moieties, aglycone monolignols and glycone d -glucose ( d -Glc), play essential roles in a cooperative manner in delivery of hydrophobic and highly reactive p -hydroxycinnamyl- (H), coniferyl- (G) alcohols to the hydrophilic site of lignin deposition. The physical, chemical and biological properties of wood depend on the supramolecular assembly of cellulose microfibrils (CMFs), hemicelluloses (HCs) and lignin in the growing cell walls.
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Norwegian Register for Scientific Journals, Series and Publishers.KESLI-NDSL (Korean National Discovery for Science Leaders).Journal Citation Reports/Science Edition.Japan Science and Technology Agency (JST).CNKI Scholar (China National Knowledge Infrastructure).Chemical Engineering and Biotechnology Abstracts.Chemical Abstracts Service (CAS) - SciFinder.Chemical Abstracts Service (CAS) - CAplus.AGRICOLA (National Agricultural Library).Holzforschung ist in den folgenden Services indiziert:
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