Wood Moisture Content Measurement by X-Ray Exposure Method

lNTRoDUCTIONTheon-sitcnon-dcstructit'cmcasurcl11cntofu.oodmoisbocontcntattTactsgrcatintcrcsts.Itpla3'simpor-tantpartsinthescicntificrcscarchsucl1asonthchcatandmasstransportproccssesint"ooddri'ing.thcim-pregnationofliquidinxt'ood.thcmoisturccontcntdistri-b…     

Relationships between preference, rumen degradability, gas production and chemical composition of browses

The aim of this work was to assess whether degradability, gas production or chemical constituents could predict the preference of browses. Forty tropical browse species leaves with a crude protein (CP) content ranging from 79 to 307 g kg^-1 DM were used for this study. The neutral detergent fibre (NDF) ranged from 220 to 694 g kg^-1 DM, while acid detergent fibre (ADF) ranged from 146 to 523 g kg^-1 DM. The NDF-bound nitrogen (NDFN) and ADF-bound nitrogen were particularly high in Calliandra calothyrsus, Acacia polyacantha, Sesbania sesban, Acacia venosa and Acacia hockii. High levels of tannins were observed in Acacia species especially A. dolichocephala, A. hockii, A. microbotrya and A. salicina. High levels were also observed in Flemingia macrophyla and Leucaena pallida. The browse species differed (P < 0.05) in DM in sacco degradability coefficients. High potential degradability (PD) and effective degradability (ED) were observed in Sesbania spp, Moringa stenopetala, Indigofera arrecta, Chamaecytisus palmensis and Atriplex spp. The browses differed (P < 0.05) in asymptotic gas (Ag) production (ml g^-1 OM), but had similar (P > 0.05) times of incubation at which half of the asymptotic gas had been formed. Preference and DM intake were positively correlated (P < 0.01) to NDFN, but negatively correlated (P < 0.05) to NDF and ADF. The PD and Ag were negatively (P < 0.001) related to NDF, ADF and lignin. Total phenols (TP) and condensed tannins (CT) were negatively (P < 0.05) related to PD, ED and Ag. A positive correlation was observed between CT and NDF-bound condensed tannins (r = 0.55, P < 0.001) and, CT and TP (r = 0.40, P < 0.01). Prediction equations were poor for DM intake and preference, moderate for gas production and good for potential and effective degradabilities. The phenolic components were more related to dry matter degradation and gas production than to preference and dry matter intake. NDFN and Ag made a positive contribution to both preference and DM intake. It was concluded that chemical constitutes such as N, NDF, NDFN, ADF and lignin are essential to predict the nutritive value of browses. This revised version was published online in June 2006 with corrections to the Cover Date.     

Crystallity Change of Compressed Poplar Wood Treated by PF Resin

INTRODUCTIONWith the implementing of the Natural ForestryProtection policies in China, the plantation forestry willplay a much larger part in meeting the demand for wood.But the plantation wood, especially Poplar and Fir, havecommon properties of soft structure, low density andpoor processing. Generally speaking, these propertiescan be evidently improved by compressing. MasafumiInoue et al. (1991a, 1991b, 1990) had studied thesurface compression of coniferous wood. Their studiesshowed …     

杨树微纤丝角的变异及其与木材性质的相关关系

微纤丝角为细胞次生壁S2层微纤丝排列方向与细胞主轴所形成的夹角,与木材的物理性质、力学性质和化学性质都有着直接的关系。应用x射线衍射法测定了7个杨树无性系(14株样木)胸径处各年轮的微纤丝角,并对应分析和测定了各年轮的木材基本密度、纤维长度、纤维宽度和纤维素含量。研究结果表明,杨树微纤丝角在年轮间存在显著差异,其径向变异规律为从髓心向外以微纤丝角逐渐降低,年轮间的平均微纤丝角在7.8旱?8褐洌荒静幕久芏取⑾宋ざ取⑾宋矶群拖宋睾吭谀曷旨湟泊嬖谙灾钜臁O喙胤治霰砻鳎⑾怂拷怯肽静幕久芏取⑾宋ざ取⑾宋矶群拖宋睾看嬖谙灾母合喙毓叵??0.01),相关系数分别为-0.450、-0.586、-0.516和-0.660。回归分析结果表明,多项式方程可较好地描述杨树微纤丝角与所测定的木材性质的关系,相关系数均在-0.45以上(n=125)。本文的研究结果认为,在今后针对杨树材性改良的育种计划中,微纤丝角是一个重要的选育和改良指标。图3表3参34。     

橡子利用的研究（Ⅲ）——橡实淀粉的特性

研究了橡实淀粉的化学成分、颗粒形貌、Ｘ－射线衍射图谱与模型、碘亲和力与链淀粉含量、差热分析、糊化温度、糊粘度曲线及冰融稳定性等性质，并对其利用的可能范围进行了分析．     

巴西橡胶树不同抗风性品系木材胞壁纤丝角

应用X射线（002）衍射的Cave法，对巴西橡胶树的13个具不同抗风力的品系PR107、海垦1、RRIM600、PB86、GT1等主干和枝干木材纤维壁的（微）纤丝角，进行了初步测试分析，结果表明：主和枝干木材纤维壁S2层的纤丝角，在抗风和弱抗风品系之间存在着明显的差异；品系的抗风力与木材纤维S2层纤丝角度有一定的关系，抗风品系的木材纤维壁S2层纤丝角度较小，弱抗风品系的纤丝角度较大；主干木材纤维S2层纤丝角度小于枝干材的纤丝角度。     

红毛丹组织X射线衰减系数与其密度的相关性

通过分别测定红毛丹果实各部分的厚度,并利用X射线图像测定射线强度,研究其X射线衰减系数,同时研究衰减系数与其密度的相关性,建立射线强度和厚度的回归方程以及果实的衰减系数与果实的果皮、果肉、果仁衰减系数的关系,为外形尺寸大小的分级奠定基础。     

Muscle fibre type distribution of the thoracolumbar and hindlimb regions of horses: relating fibre type and functional role

Background

Although the majority of equine muscles have a mixed fibre type distribution indicative of diverse functional roles, the predominance of a fibre type can indicate the primary function of a muscle. The deep epaxial musculature has an important role in core spinal stability in humans, reflected as a predominantly muscle fibre type (MFT) I or postural fibre type. The fibre type of the deep epaxial musculature has not been determined in horses. The objective of the study was to determine the MFT distribution in selected muscles of thoracolumbar and hindlimb region of horses. This included deep epaxial and hypaxial muscles that were hypothesised to have a postural stabilising role. A second objective was to examine differences in MFT distribution between horses bred for endurance (Arabian) and sprinting (Quarter horse). Muscle biopsy samples were obtained from selected thoracolumbar and hind limb muscles of 5 Quarter horses, 4 Arabians, and 2 Thoroughbreds. The myosin heavy chain distribution was determined by gel electrophoresis. Mann–Whitney rank test was used to compare the proportional MFT and differences between breeds.

Results

Mm. sacrocaudalis dorsalis medialis and diaphragm had the highest proportion of MFT-I. The remaining deep epaxial muscles and the hypaxial muscle m. psoas minor had approximately equal MFT I and II proportions. Mm. psoas major, iliocostalis, longissimus dorsi and the hind limb muscles contained mostly MFT-IIX. The fibre type distribution was similar between Arabians and Quarter horses, although Quarter horses had more MFT-IIX fibres in psoas major (P = 0.02) while Arabians had more MFT-I fibres in m. longissimus dorsi (P = 0.03).

Conclusions

The fibre type distribution of the deep epaxial muscles, mm psoas minor and diaphragm varied from approximately equal MFT-I and II proportions to predominantly MFT-I suggesting a postural stabilising role possibly important in core spinal stability. In contrast the fibre type proportions of mm psoas major, iliocostalis, longissimus dorsi and the hind limb muscles were mainly MFT-II suggesting a locomotory role. Knowledge of fibre type distribution in such a clinically important area can direct diagnosis, prevention and treatment of muscular or neuromotor dysfunction.     

Food and water intake and selective feeding in rabbits on four feeding regimes

Diet plays an important role in maintaining rabbit health. Feeding an incorrect diet, particularly a low fibre diet, has been linked with digestive, dental and urinary tract disease. However, food intake and dietary requirements have been poorly studied in pet rabbits. This study assessed the effects of two commonly fed pet rabbit diets [extruded nuggets with hay (EH) and muesli with hay (MH)] alongside hay only (HO) and muesli only (MO) on food and water intake in 32 Dutch rabbits. Dry matter (DM) intake was greater in the HO group and lower in the MO group than in the EH and MH groups (p < 0.001). The portion of the diet made of hay was greater in the EH group than in the MH group (p < 0.001). Water intake was positively correlated with DM intake and was greatest in the HO group (p < 0.001). Selective feeding occurred in all rabbit groups fed muesli, whether or not hay was also available. Pellets were rejected, and grains and extrudates selected. The presence of selective feeding in all rabbits fed muesli leads to the consumption of an unbalanced diet. In addition, hay intake and water intake were lower when muesli was fed. Conclusions drawn from this study are based on general recommendations for pet rabbits, and clinical disease may have developed by feeding the study diets over a longer time period, as many diet‐related conditions typically present in older rabbits. However, the study demonstrates that the feeding of muesli diets cannot be recommended.     

乙醛、对苯二甲酸、乙二醇对鲢、草鱼的联合毒性

实验按毒性单位1：1：1设计，研究乙醛、对苯二甲酸、乙二醇等化纤污水中主要污染物对鲢、草鱼的稚鱼和幼鱼的联合毒性。实验结果表明，乙醛＋对醛二甲酸＋乙二醇对鲢的稚鱼和幼鱼的96hLC50值分别为21300．6和27438.8mg/L；对草鱼的稚鱼和幼鱼的96gLC50值分别为27387．3和25606．2mg/L。联合毒性效应均表现为相加作用。