香菇品种对木霉抗性的测定

研究了１２种香菇对绿色木霉的抗性，根据不同品种的长势和抗性情况，将香菇品种抗霉性大致分为抗霉性较强，抗霉性中等、无抗霉性３种。抗霉性较强的品种有８９１１、日Ｈ－３、日Ｓ５１０、沈－０８７、９０８，抗霉性中等品种有２４１－４、８２－２、１２１，无抗霉性品种有日Ｇ－５８、７４０２、沈－０４，闽优－４。     

银杏盆景能抗癌

银杏盆景被誉为“有生命的艺雕”。银杏树叶形状美丽，春夏一片葱绿．秋天色泽金黄，给人以华贵典雅之感。有关资料表明，银杏树能抗污染、抗烟尘，抗水渍、抗核辐射、抗病虫害、抗严寒酷暑，具有很强的生命力。     

葡萄抗根结线虫资源筛选

对供试的38份葡萄资源，包括我国原产的10份葡萄野生种类、生产上常用的4份葡萄栽培品种、20份葡萄砧木品种和4份山欧杂种的对南方根结线虫的抗性鉴定，建立了完善的葡萄抗性鉴定评价体系。鉴定结果为：葡萄种质资源间抗根结线虫的能力有很大差异，抗性的分布有5种类型，即免疫、高抗、中抗、中感和高感类型。（1）原产我国的野生资源抗线虫性：原产我国的葡萄野生资源，没有发现免疫类型，从供试的10个种对根结线虫的抗性划分为4个类型，第一类为高抗资源（HR），分别为华东葡萄和毛葡萄；第二类为中抗资源（MH），分别为复叶葡萄、刺葡萄、蘡薁和华北葡萄；第三类为中感（MS）资源，分别为燕山葡萄、山葡萄和葛藟；第四类为高感（HS）资源，小果野葡萄。（2）栽培品种的抗线虫性：从供试的4个主要栽培的品种来看，目前我国葡萄产区主栽品种均不抗葡萄根结线虫。但存在抗根结线虫的阶段性差异，欧美杂种的抗线虫性强于欧亚种的栽培品种。（3）葡萄砧木品种的抗线虫性：第一类，砧木品种表现为免疫或极抗。有4个：3309P、Champini、Dog Ridge、Riparia 580。第二类，表现为高抗。有Grand Glaber、5BB、5C、Barrett50、Pulliat、Freedom、抗砧3号。第三类，表现为中等抗性。有贝达、SO4。第四类，表现为中等感染。有Salt Creek、Gloire、Eldorado、Rupestris 2、华佳8号。第五类，表现为感染。有Eldorado 、Macadams 、1613C。（4）山欧杂种的抗线虫性：4份山欧杂种均不抗葡萄根结线虫，但山欧杂种的抗线虫能力存在差异，抗性能力的高低与欧亚种的对后代遗传力有密切关系。     

再生木纤维制备成型颗粒燃料物理性能的初步研究

以废弃纤维板所制再生木纤维为原料，采用环模制粒机把原料压缩为成型颗粒燃料。通过试验测定了成型燃料的密度、抗跌碎性、抗渗水性和吸湿性等。结果表明：原料的纤维形态和特性对成型燃料的密度、耐久性有显著影响。实验中，再生木纤维所制颗粒燃料的密度均为1.21 g/cm3，略小于再生木刨花所制颗粒燃料密度；两种再生纤维形态成型后的跌碎率分别为0.36%和0.59%，吸水率相差不大，约为7.90%，与再生木刨花和贴面再生木刨花所制颗粒燃料相比，其抗跌碎性较好，但抗渗水性能略差；吸湿率为1.03%，抗吸湿性较好。纤维比表面积越大，纤维间填充度就越高，结合越紧密,其成型燃料的密度就越大，抗跌碎性也越好，但抗吸水性越差。     

室外木结构用胶粘剂胶合制品分层试验对比

以红松、落叶松、杉木和桦木为试验材料，使用苯酚-间苯二酚-甲醛树脂胶粘剂（RPF）和酚醛树脂胶粘剂（PF），将试材顺纹胶合成抗分层试件，经过3个真空-加压-真空-加压-干燥循环，研究2种胶粘剂的抗分层能力。试验表明，RPF树脂与PF树脂的抗分层能力相近，桦木试件的抗分层能力低于其他木材试件。     

胡杨幼苗生长习性与成苗

胡杨属高大乔木，是一种干旱大陆性气候条件下生长的树种。该树种喜光、抗热、抗大气干旱、抗盐碱、抗风沙，寿命可达百年，可生长在pH值7．3—9的土壤中。     

胡杨良种壮苗的培育

胡杨因具有很强的抗风沙、抗沙埋、抗盐碱、抗寒、抗涝、排碱等作用而成为干旱沙漠地区防风固沙、植树造林的主要树种。但是，由于胡杨种子的生命期短不易保存，种子极细小、采收困难，制约了优良苗木的繁育和发展，因此，加快了良种的选择与壮苗的培育对干旱和沙漠地区改造环境，防止土壤沙漠化及防风固沙等有着极其重要的战略意义。     

抚仙湖流域磷矿区主要植物群落水土保持效应研究

通过对抚仙湖流域磷矿开采区8种主要植物群落类型水土保持效应的研究，探讨了不同植物群落的抗径流和土壤侵蚀的能力以及与土壤抗蚀性之间的关系；筛选出水土保持效应较优的植物群落。研究表明：竹林群落和旱冬瓜林群落的抗径流能力和抗土壤侵蚀能力较强，可作为该地水土保持的先期植物群落。荒草地和矿渣废弃地水土流失严重，土壤抗侵蚀性差，应进行植树造林和加强封育管理。云南松林、华山松林、桉树林、灌木林的土壤抗侵蚀性稍逊于竹林和旱冬瓜林，营造水土保持防护林时可适当考虑。     

大跨度预应力空心楼盖的施工抗浮

对大跨度预应力空心楼盖的施工抗浮问题，从施工过程的发生、发展以及抗浮的受力分析、抗浮的处理方法等作了深入的研究，对该类问题的施工解决提出了新的可行的办法。减少了施工的盲目性，减少了大跨度通情达理应力空心楼盖抗浮施工时各种质量问题的发生，填补了“空心管＋预应力”技术在施工应用方面的一项空白。     

粉煤灰钢纤维混凝土路用性能的研究

文章研究了粉煤灰钢纤维混凝土的抗压强度、抗折强度，分析了掺钢纤维及粉煤灰对混凝土抗压强度、抗折强度的影响，试验结果表明，混凝土掺钢纤维和粉煤灰能提高混凝土的抗折强度与折压比，可应用于路面工程中。     

线弹性断裂力学原理在木材中应用的特殊性与木材顺纹理断裂

阐述了线弹性断裂力学 (LEFM)的原理以及在木材中应用的特殊性 ,并以杉木和马尾松为研究对象 ,采用不同试样和方法测定了木材的顺纹断裂韧性KTLIC 。研究表明 ,建立在各向同性体之上的LEFM原理对木材裂纹顺纹扩张是适用的 ,其顺纹断裂韧性是木材的固有属性     

人工林杉木、马尾松木材的断裂特性

使用扫描电子显微镜观察杉木、马尾松横纹拉应力、顺纹拉应力及冲击载荷作用下的破坏表面，结果表明不同的加载方式、加载速率对木材的断裂过程有影响；木材的微观构造影响其断裂过程。     

Hardness distribution on wood surface

For better understanding wood hardness, we developed a new hand-operated hardness tester that works with Brinell's method. With this tester we investigated the hardness distribution of wood minutely using a 2mm diameter ball tip. The following results were obtained: (1) On preliminary examination with medium-density fiberboard, we found that the value of Brinell's hardness decreased with the increase in the tip ball's diameter but that it was almost constant with the indenting velocity. (2) By using a small diameter tip, the difference of the hardness became clearer between earlywood and latewood. (3) With radial and tangential sections, we obtained hardness distribution patterns similar to those of wood grain. It seems that the hardness distribution reflects the distribution of density on wood surfaces.     

Orthogonal cutting mechanics of maple: modeling a solid wood-cutting process

The experimental results of orthogonal cutting of maple and the modeling of the cutting mechanics are presented. The tool cutting forces were measured for different feed rates. A set of equations relating the tangential and feed forces to the tool edge width and feed rate (chip thickness) to calculate the chip and edge cutting force coefficients was developed. Then the chip force and edge force coefficients were calculated from experimentally obtained cutting forces and were plotted in a polar-coordinate system with respect to the fiber orientation of the maple disk. The polar-coordinate presentation of the cutting force results and the calculated cutting force coefficients provides an excellent visual appreciation of the relation between the cutting forces and the wood fiber orientation. Chips were also collected from various sectors of the wood disk. This analysis further identified the effects of fiber orientation and cutting forces on the types of chip formed and hence the cutting mechanics involved. By applying the calculated cutting coefficients for each tool orientation (in respect to the grain) it is possible to predict the feed and tangential forces for any feed rates. There is good agreement between the predicted and measured cutting forces.     

Derivation and application of an equation for calculating shear modulus of three-ply laminated material beam from shear moduli of individual laminae

In a detailed study of the relation between the deflection caused by shear force and the constitution of a laminated material beam, we derived an equation for calculating the shear modulus of a laminated material beam from the shear moduli of individual laminae. The validity of the derived equation was investigated using crosslaminated wood beams made with five species. The calculated shear moduli parallel to the grain of face laminae ranged from 48.3 MPa to 351 MPa, while those perpendicular to the grain of face laminae ranged from 58.0 MPa to 350 MPa. The calculated shear moduli increased markedly with increasing shear modulus in a cross section of perpendicular-direction lamina of a cross-laminated wood beam. The calculated apparent modulus of elasticity (MOE) of cross-laminated wood beams agreed fairly well with the measured apparent MOE values. This fact indicated that the apparent MOE of cross-laminated wood beam was able to be calculated from the true MOE values and shear moduli of individual laminae. The percentage of deflection caused by shear force obtained from the calculated apparent MOE (Y _sc) was close to that obtained from the measured apparent MOE (Y _s) and there was a high correlation between both values. From the above results, it was concluded that the derived equation had high validity in calculation of shear modulus of a cross-laminated wood beam.     

竹节对竹材力学强度影响的研究

本文对毛竹和刚竹的带节材与不带节竹材的主要力学性质研究表明,带节竹材的抗弯强度、顺纹抗压、抗剪、抗拉强度和冲击韧性都有一定程度降低的趋向,但抗劈开强度和横纹抗拉强度却有明显提高。影响竹材力学强度的主要因素是维管束数量、维管束排列方向及维管束中纤维的力学强度,了解这些规律,对复合材料的结构仿生有重要参考作用。     

Fracture of multiply-bolted joints under lateral force perpendicular to wood grain

The crack initiation and propagation of multiplybolted joints subjected to lateral forces perpendicular to the grain were analyzed. Two types of bolted joint were subjected to lateral loads perpendicular to the grain. One had joints of two bolts aligned with the wood grain (type H), and the other had joints of two or three bolts aligned perpendicular to the grain (type V). The crack initiation and propagation were analyzed by means of the average stress method (ASM) and linear elastic fracture mechanics (LEFM), respectively. The maximum loads calculated by LEFM agreed comparatively well with the experimental results, and it was proved that the LEFM was an appropriate tool to analyze the fracture of multiply-bolted joints subjected to a force perpendicular to the grain. It was also found that the multiply-bolted joints failed with the fracture of the wood before the joints yielded, and that it caused a considerable decrease of the maximum loads. The reduction of strength should be considered in the design of multiply-bolted joints subjected to lateral forces perpendicular to the grain.Part of this work was presented at the annual meeting of the Architectural Institute of Japan, Hikone, September 1996     

Nonlinear superposition model for the behavior of bolted joints

Summary A previously developed model to predict the load-slip relationship for mechanical joints using one bolt subjected to lateral loading (Part 1) was extended to incorporate the rotational resistance of joints containing two bolts. The rotation is about the long axis direction of the bolts, and considers the wood members oriented at arbitrary angles to the grain. The model utilizes nonlinear translational springs to represent the parallel and perpendicular to grain components of the reaction force present on each bolt resisting the applied moment. A series of experiments were conducted to determine the spring constants of bolted joints in axial loading and to verify the predictions of the mathematical model. Bolted joints subjected to a pure rotation were tested using combinations of steel plates and wood side members experiencing bolt reaction forces at various angles of load to grain. The results indicated an excellent agreement between theoretical predictions and experimentally obtained data.The authors wish to extend thanks to the Colorado State Agricultural Experiment Station for their financial support and to the Fulbright-Hayes Foundation for the educational scholarship and research funding provided to the project     

Propagation behavior of acoustic wave in wood

We used acoustic tests on a quarter-sawn poplar timbers to study the effects of wood anisotropy and cavity defects on acoustic wave velocity and travel path, and we investigated acoustic wave propagation behavior in wood. The timber specimens were first tested in unmodified condition and then tested after introduction of cavity defects of varying sizes to quantify the transmitting time of acoustic waves in laboratory conditions. Two-dimensional acoustic wave contour maps on the radial section of specimens were then simulated and analyzed based on the experimental data. We tested the relationship between wood grain and acoustic wave velocity as waves passed in various directions through wood. Wood anisotropy has significant effects on both velocity and travel path of acoustic waves, and the velocity of waves passing longitudinally through timbers exceeded the radial velocity. Moreover, cavity defects altered acoustic wave time contours on radial sections of timbers. Acous-tic wave transits from an excitation point to the region behind a cavity in defective wood more slowly than in intact wood.     

乐昌含笑木材构造和性质

本文对乐昌含笑的木材构造和木材物理力学性质进行了研究。结果表明,乐昌含笑生长迅速,树干通直,其木材纹理直,密度小,质软,结构中而均匀,干缩差异小。且具有易干燥、不翘曲、不弯裂等优点,材性类似于杨树。适于作纸浆和胶合板等用材。