黑木耳膨化脆片的制作方法

试验以黑木耳和不同淀粉为主要原料,制作黑木耳膨化产品。比较马铃薯、玉米、木薯淀粉在配方和工艺等不同条件下的膨化效果,筛选出最佳淀粉原料和配方。结果表明,木薯淀粉的膨化效果优于其他淀粉,木薯淀粉和黑木耳粉制作膨化脆片产品的最佳配方和工艺:黑木耳粉和淀粉的比例为1∶19,加水量和淀粉比例为1∶1,高温蒸煮温度为125℃,蒸煮时间为40 min。     

木材微波处理技术与应用进展

木材在微波作用下可迅速升温超过180℃,内部水分汽化后以蒸汽形式逸出,冲破木材内部薄弱组织。处理后木材的微观结构变化分可为7级,宏观处理效果分为3型。微波技术主要用于木材干燥、膨化、弯曲和检疫等。通过微波膨化技术获得的"微波膨化木"可用于加工制造高性能的改性木、防腐木、阻燃木、木质装饰材料和高导热木材等。     

全脂膨化大豆在仔猪、生长猪日粮中的应用

全脂膨化大豆是新一代饲料原料，它含有较高的粗脂肪、粗蛋白、亚油酸等营养成分。大豆经过膨化后其中的抗胰蛋白酶、沙门氏菌等抗营养因子被破坏，各种营养物质被分解成小分子物质从而易被动物吸收利用。目前国内一些厂、场已在猪饲料中应用并取得了较好的结果，本次试验...     

冷冻预处理对樟子松微波膨化程度及均匀性的影响

采用MATLAB图像处理方法,研究含水率、冷冻时间和冷冻温度对樟子松冷冻预处理后微波膨化程度及均匀性的影响。结果表明:试材含水率20%时膨化效果较好,含水率在纤维饱和点以上时,在一定范围内,提高含水率可增大膨化程度,但膨化均匀性较差;冷冻时间延长能够提高膨化程度,对膨化均匀性影响不显著,以冷冻36 h时的膨化效果较好;冷冻温度降低可提高膨化程度,但温度过低使膨化均匀性变差,以–20℃冷冻时的膨化效果较好。     

微波膨化木装饰表板实木复合地板通过鉴定

<正>由浙江富得利木业有限公司、中国林科院木材工业研究所、南京林业大学共同研发的"微波膨化木装饰表板实木复合地板",2018年12月通过了中国林产工业协会组织的新产品鉴定。鉴定委员会的专家查验了生产现场,听取了汇报,审查了鉴定材料,查看了样品,经质询和讨论,一致认为:该产品以微波膨化木为基材,采用快速均匀浸     

微波膨化山野菜脆片的研究

研究了微波膨化技术在山野菜脆片加工中的应用。以黄瓜香（荚果蕨）为原料,实验了淀粉原料的不同膨化效果,不同比例淀粉原料与黄瓜香浆混合膨化效果,黄瓜香样品定型厚度与膨化效果,经过正交实验综合考虑最终确定微波膨化黄瓜香脆片的最佳条件,物料厚度1mm ,微波功率375W ,膨化时间6．5min。保留了原山野菜的风味,使产品口感更加细腻柔和。     

中药液体制剂常温瞬间超高压灭菌技术

在中药膨化技术和超高压水射流技术的启示下，提出本研究项目，首创了微生物膨化灭菌的概念；首次利用超高压水射流原理对中药液体制剂中的微生物通过膨化、剪切和高速撞击等综合效应，以达到瞬间杀菌的目的，并由此建立一种常温灭菌新方法。此方法的机理是：在超高压下蛋白质仍保持球形，水分子之间的距离将缩小，并渗透和填充到蛋白质内的氨基酸周围，当超高压瞬间减压后，水分子汽化而发生爆炸，巨大的膨化压力破坏了蛋白质的空间结构，     

稻壳膨化机变废为宝

辽宁省农机所和沈阳市饲料膨化机厂不久前试制成功了 DP—120型稻壳膨化机,样机通过了省级鉴定。该机可将稻壳经螺杆挤压膨化成粉末状,使其所含营养成分释放出来,变成具有米糖香醇味的适口饲料。这种设备还可膨化花生壳,加入适量稻壳还可膨化湿茧蛹、湿羽毛、鸡粪等。膨化稻壳除作饲料外还可作食用菌培     

铁路桥梁混凝土表面气泡和砂纹的防治措施

通过对铁路桥梁混凝土表面气泡和砂纹形成原因的分析,从桥梁预制工艺5个方面进行试验研究,并提出了相应的防治技术措施。     

中孔高性能粒状活性炭的研制

以果核壳为原料，采用磷酸活化法制备中孔高性能粒状活性炭，制备过程为：粗粒果核壳中加入质量分数为85%的磷酸加热和定时搅拌，使其润胀膨化，直至粘滞性消失，物料呈分散状态，然后炭化，活化、水洗、烘干。用正交试验法考察了润胀膨化，炭化和活人的温度及时间对制品性能的影响，并作了不同处理原料方式的比较试验，样品性能的测试结果：四氯化碳吸附率最高约160%，A法焦糖脱色力最大约130%。强度最高约94%，总也容积最大1.7mL/g，中孔比例约占40%-50%。     

Toward an improved model of maple sap exudation: the location and role of osmotic barriers in sugar maple, butternut and white birch

Two theories have been proposed to explain how high positive pressures are developed in sugar maple stems when temperatures fluctuate around freezing. The Milburn-O'Malley theory proposes that pressure development is purely physical and does not require living cells or sucrose. The osmotic theory invokes the involvement of living cells and sucrose to generate an osmotic pressure difference between fibers and vessels, which are assumed to be separated by an osmotic barrier. We analyzed wood of Acer saccharum Marsh., Juglans cinerea L. and Betula papyrifera Marsh. (all generate positive pressures) examining three critical components of the osmotic model: pits in cell walls, selectivity of the osmotic barrier and stability of air bubbles under positive xylem pressure. We examined the distribution and type of pits directly by light and scanning electron microscopy (SEM), and indirectly by perfusion of branch segments with fluorescent dyes with molecular masses similar to sucrose. The latter approach allowed us to use osmotic surrogates for sucrose that could be tracked by epifluorescence. Infusion experiments were used to assess the compartmentalization of sucrose and to determine the behavior of gas bubbles as predicted by Fick's and Henry's laws. The SEM images of sugar maple revealed a lack of pitting between fibers and vessels but connections between fiber-tracheids and vessels were present. Fluorescein-perfusion experiments demonstrated that large molecules do not diffuse into libriform fibers but are confined within the domain of vessels, parenchyma and fiber-tracheids. Results of the infusion experiments were in agreement with those of the fluorescein perfusions and further indicated the necessity of a compartmentalized osmolyte to drive stem pressure, as well as the inability of air bubbles to maintain such pressure because of instability. These results support the osmotic model and demonstrate that the secondary cell wall is an effective osmotic barrier for molecules larger than 300 g mol(-1).     

规格材强度性能测试方法的研究进展

规格材是现代轻型木结构建筑的主要用材.本文简要阐述了规格材的相关概念、北美分级测试系统的研究进展,分析了不同测试条件对强度测试值的影响,结合我国现状,预测今后规格材强度测试的发展趋势并提出建议.     

Manufacture and properties of ultra-low-density fiberboard

Low-density fiberboards with densities ranging from 0.05 to 0.50g/cm³ were manufactured with steam injection pressing. Bond-type and foam-type isocyanate compound resin adhesives were used separately at 10% and 30% resin content levels. Two types of different-size fibers from softwood were used. Mechanical, dimensional, thermal, and sound insulation properties of the fiberboards were tested. The results are as follows: (1) Bond-type isocyanate adhesive showed higher mechanical and dimensional properties of low-density fiberboards than the foam-type adhesive. (2) Fiberboards produced from small fibers have better mechanical and dimensional properties than those made from large fibers. (3) Thermal conductivity of fiberboards depends more on the board density than on the type of resin or fiber dimension. At a board density lower than 0.2 g/cm³, the thermal conductivity is almost equivalent to those of thermal insulation materials such as polystyrene foam and rock wool, (4) Generally, the sound absorption coefficient of low-density fiberboards tends to increase at higher sound frequency. As the board thickness increases, low-frequency sounds are more readily absorbed by boards.Part of this report was presented at the 46th annual meeting of the Japan Wood Research Society, Kumamoto, April 1996     

Effects of low bondability of acetylated fibers on mechanical properties and dimensional stability of fiberboard

Fiberboards were prepared from acetylated fibers with various weight gains: 0, 4.7, 9.4, 18.5, and 24.8 weight percent gain (WPG). The effects of low bondability of acetylated fibers on mechanical properties and dimensional changes were determined. The decreased mechanical properties of acetylated fiberboard are mainly due to low bondability. To improve bending strength, high face density is also needed. The thickness swelling according to JIS and the linear expansion under relative humidity changes decreased with increasing WPG. As for accelerated weathering and the outdoor exposure test, the thickness changes in 4.7–18.5 WPG boards were much higher than those in OWPG board and 24.8 WPG board. The high thickness change in 4.7–18.5 WPG boards is due to low bondability. Although 24.8 WPG board also has low bondability, the thickness change of 24.8 WPG board decreased. The high dimensional stability of acetylated fibers, caused by high WPG, probably outweighs the dimensional change caused by low bondability. On the other hand, during the boiling test the thickness changes in 24.8 WPG board and the 4.7–18.5 WPG boards were higher than those in 0 WPG board. The effect of the boiling test on the boards is more severe than that seen with the accelerated weathering and outdoor exposure test; therefore, the effects of the low bondability probably cancel the effects of the high WPG. It is necessary to increase the bondability of acetylated fibers to improve the dimensional stability and the mechanical properties.     

油桐花序石蜡切片制作方法改良

【目的】为了获得利用石蜡切片方法观察油桐花芽形成和分化的整个过程的最佳效果,探索针对油桐花序的石蜡切片方法。【方法】以横纵径1 cm左右的油桐花序为实验材料,针对材料处理、脱水、透明、浸蜡、包埋、染色等传统石蜡制片步骤进行改良。【结果】1)保持样品结构不变的情况除去多余苞片、分支以及密实缠绕在小花萼片外的绒毛,使得药液和蜡液更易进入材料内部,避免了由于油桐花序苞片紧实,绒毛极多所导致的脱水、浸蜡不充分等现象;2)改良后的乙醇脱水时间缩短了1 h,并且材料脱水充分,避免了因脱水透明时间过长引起的材料变硬变脆,保证了石蜡可以与材料形成密不可分的整体,切片时能得到完整和连续的蜡带;3)延长浸蜡时间为1 d,保证大体积材料也能浸蜡充分,包埋过程选择在恒温烘箱中进行,保证器械与材料温度一致,避免了两者产生温差导致材料中产生气泡的不良现象,保证材料的完整性。染色后的切片细胞核颜色红亮鲜艳,核质分明,细胞间轮廓清晰,不论是花序的整体形态结构,还是不同组织的细胞结构,均清晰可见。【结论】通过对传统制作石蜡切片方法进行改良有效地解决了油桐花序石蜡切片制作过程中由于其复杂的花序结构及其分泌物质而引起的不良效果以及脱水过度、浸蜡不充分而导致的材料结构不完整、切片易碎等问题,获得了完整连续的蜡带以及结构完整、染色清晰的油桐花序切片。以期望该方法为研究油桐花芽分化及雌雄花发育的细胞学特征提供良好的技术支撑,为快速高效批量制作油桐花序石蜡切片提供了质量保证,同时也为花序结构复杂、外部密披绒毛树种的石蜡切片制作提供参考。     

燃煤电厂脱硫塔浆液起泡微观表征分析研究

利用彬长电厂和当涂电厂脱硫塔浆液起泡泡沫,通过X射线衍射法、傅里叶扫描电子显微镜法以及变换红外光谱法分析了吸收塔浆液泡沫样品的微观表征。结果表明:起泡和未起泡浆液在晶体形态、官能团上等具有相似的微观特征。但在形态结构上存在较大差异,起泡浆液的结构稳定性较差,存在使结构分裂的层间作用力。浆液结构变成杂乱无序的层状,其结晶水的含量也大幅度增加。     

Senile coconut palms: Functional design and biomechanics of stem green tissue

This study aims at determining the biomechanical behaviour and functional design, at integral level of hierarchical structure, of senile coconut palms (greater than 80 years old). To achieve the objectives, 46 stress/strength analyses were performed on characteristic coconut palm stem green tissues (referred to as cocowood herein) by means of three dimensional finite element analysis (FEA). To estimate the material damage produced when the stresses rose beyond the material strength, the Tsai-Hill failure criterion was used; the progressive material failure was predicted and mapped for seven wind speeds of different categories. Parametric analyses were performed to further analyse the influence of fibrovascular bundle orientations and density distribution on the cocowood stem functional design. The research outcomes showed an optimum orientation of characteristic fibrovascular bundles and an improved cocowood structure in terms of mechanical efficiency and capacity to resist high wind loadings. The analyses allowed for a better understanding of the cocowood biomechanics and functional design, especially the significance of its structural-mechanical advantage over other palm species and trees. As no similar research on the cocowood biomechanics using FEA had been conducted before, the knowledge advanced from the current study has far-reaching implications for enhancing wood materials from a biomimetic perspective.     

可降解木塑复合缓冲包装衬垫材料的研究综述

可降解木塑复合发泡材料的研究可提高木质剩余物的利用率,缓解资源短缺的压力,同时可以减少通用塑料发泡缓冲材料对环境的污染,具有重要的社会意义和经济效益.从天然纤维及其性质、增韧改性、界面相容性等方面对国内外可降解木塑复合发泡材料的研究现状进行分析,指出木塑复合发泡缓冲材料存在的问题,并对可降解木塑复合缓冲材料的发展趋势作出展望.     

Wood-polymer combinations: The chemical modification of wood by alkoxysilane coupling agents

Summary Vinyl polymers in wood-polymer combinations fill cell cavities but do not bond to nor enter cell walls to any noticeable extent. The wood dimensional stability thus remains virtually unchanged. Nonleachable-bulking treatments which react with the cell wall material tend to diminish wood strength properties and do not appear to show promise for providing a link between the cell wall and the polymer. Alkoxysilane coupling agents are widely used to modify the interface between dissimilar materials, such as glass fibers and thermoplastic or thermosetting resins. The coupling agent -methacryloxypropyltrimethoxysilane was used in this study with trembling aspen, white birch and eastern white pine woods. Antishrink efficiencies comparable to those reported for reactive chemical wood modifiers were obtained. This treatment did not require acidic or basic reaction conditions which could cause wood strength reductions. Its effects upon wood strength and the extent of bonding to the cell wall are presently under investigation.The authors are grateful for financial support by the Natural Sciences and Engineering Research Council of Canada     

Manufacture of oriented board using mild steam treatment of plant fiber bundles

This study investigated the effects of mild steam treatment (0.1 MPa for 2 h) of natural bio-based fibers and orientation (0° and 90°) of those fibers in various fiberboards. Ramie bast, pineapple leaf, and sansevieria fiber bundles were used as materials. The composite fiberboards were prepared using phenol-formaldehyde (PF) resin. To investigate the effect of mild steam treatment on wettability, contact angles of PF resin to the fiber were measured. The mechanical properties of the boards were examined as well as their dimensional stability. The contact angle data showed that mild steam treatment was effective in improving the wettability of fibers. Unioriented steam-treated boards showed better performance of internal bond (IB), moduli of rupture (MOR) and elasticity (MOE), thickness swelling (TS), and water absorption (WA) than other boards. Unioriented steam-treated sansevieria board with longitudinal fiber direction showed higher average values of MOR (403 MPa), MOE (39.2 GPa), and IB (1.33 MPa) and lower values of TS (5.15%) and WA (8.68%) than other boards. The differences in the mechanical properties and dimensional stability of boards were found mainly due to the differences in the ratios of fiber fraction of the boards to the density of the fiber bundles.