辣椒花粉的离体萌发试验

以辣椒品种2144的花粉作为实验材料,在研究硼酸和蔗糖浓度对花粉萌发和花粉管伸长影响的基础上,对辣椒花粉的培养基配方进行了优化。选出适合辣椒离体花粉萌发的液体培养基组成成分：Ca（NO3）2 200mg／L＋MgSO4 200mg／L＋KNO3 100mg／L＋H3BO3 100mg／L＋10％蔗糖,得到63．77％的萌发率,花粉管平均长度达到0．361mm。     

日本花柏木材管胞形态特征的变异

管胞长度自髓心向外,1～11a迅速增加,11a后管胞长度增加缓慢,11～26a保持相对稳定,26a后有少许的波动;管胞长度沿树干自基部向上逐渐增加,3.3～5.3m处达到最大,然后向上变短,树冠区域管胞长度最短。管胞直径与胞壁厚度在径向上变异模式基本相同,径向上从髓心向外先增加后稳定,但是胞壁厚度变化幅度比较平稳;轴向上管胞直径先有少许的增加后减少,胞壁厚度则基本呈减少趋势。管胞长宽比径向变异与管胞长度的类似,也是在11a后趋向稳定。管胞壁腔比在径向上先增加后减少,但是相对于其它性状来说,其变异模式波动较大。日本花柏平均管胞长度为1.94mm,管胞直径为27.8μm,胞壁厚度4.89μm,长宽比61.0,壁腔比0.192,为优良的造纸原料。其木材幼龄期为11a,且幼龄材与成熟材的差异大。     

麻疯树花粉管荧光染色及生长过程的研究

花粉管的生长是完成植物受精的重要生理过程,观察花粉管生长首先需要对雌蕊组织进行软化透明。本研究探索适合麻疯树雌蕊结构的透明方法,并利用苯胺蓝染色技术,在荧光显微镜下观察授粉后麻疯树花粉管的萌发和生长过程。结果表明:麻疯树雌蕊组织可采用NaOH溶液软化透明,较优的条件是2 mol·L-1的NaOH,50℃恒温箱内软化3~4 h;麻疯树授粉2 h后花粉管开始萌发,10 h后花粉管穿过花柱基部,11 h后在子房中观察到花粉管。麻疯树授粉后,花粉管进入子房至少需要11 h,完成受精则需要更长的时间。     

暴雨细沟侵蚀的调查研究

本文通过对1988年8月4～5日和1989年7月16日陕北安塞水土保持试验站出现的两次大暴雨细沟侵蚀的分析研究,得出了野外大暴雨条件下细沟侵蚀量随坡长增加近线性增大;与坡度的关系为,当坡度小于25°时,随坡度增大而增大,当坡度大于25°时,随坡度增大而减小;细沟侵蚀量在不同农耕地的变化为,翻耕后麦地>荞麦地>水平沟谷地>一般耕作豆地,细沟侵蚀量在坡面总侵蚀量中所占的比重为50%～75%。     

聚集器静压的合理确定

合理确定聚集器的静压,对气力集尘装置的经济性和工作可靠性都有重要意义。     

锐齿栎林分叶长宽比和叶干重面积比的变化

通过对辛家山林业局锐齿栎纯林的叶样本的统计分析,认为锐齿栎林分中叶长宽比和叶干重面积比的变化是显著的,这两个比值都随径级的增大而增大,在同一径级内,其变化也是较大的。     

华北落叶松天然林林冠层变化规律的研究

对林冠层的垂直变化的研究表明,树高Ｈ与天然整枝高度Ｌ相关极紧密,两因子增速比为１０：７。林冠层水平变化表现在冠径ｄ与胸径Ｄ、冠径ｄ和树高Ｈ相关均紧密,它们的增速比Ｄ／ｄ为１：１８．５、Ｈ／ｄ为４：１。林龄Ａ与冠径ｄ相关也很紧密,在同龄下,ｄ增宽速度Ⅰ地位级大于Ⅱ地位级,二者增速差距随林龄增大而加大。ｄ／ｌ与ｌ／Ｈ相关极紧密为近似直线的二次抛物线反相关类型,１０～３０年冠形变化较大,其变化速度Ⅰ地位级比Ⅱ地位级快５年,以上各相关规律可为间伐、修枝等抚育措施提出数量依据。     

Effects of fiber length and orientation on elasticity of fiber-reinforced plywood

Short carbon fibers, a reinforced material in wood veneer composites, were used to investigate the effects of fiber length and orientation of fibers on the elasticity of plywood. The technical feasibility, elasticity, and strength of the reinforced plywood with short carbon fiber were evaluated. In a short fiber reinforcement system, the fiber length does not directly influence the reinforcement in Cox's theory when the fiber length exceeded a certain length. When the length of short carbon fiber is beyond 3 mm, the high reinforced result was obtained in the experiment. However, if fiber length was too long, the reinforced result was less owing to the bridge between fibers and the increase of holes. The optimum fiber length must be considered. The orientation of fibers has a strong influence on the reinforcement. Unidirectional, perpendicular, and random orientation displayed different influence on the elasticity. Experimental results were discussed with Cox's method. Reinforced plywood with short carbon fibers in random orientation has a higher shear modulus and bending strength than the controls, in addition to other mechanical properties.     

Queue Length in the Gated Service and Limited Service Polling Systems with Bernoulli Feedback

In this paper,we consider the gated service polling system and the limited service polling system for non symmetrical stations with Bernoulli feedback,give the distributions and the first moments of queue lengths and some other results.     

相对冠长在杉木人工林立木材积测定中的应用

形数随相对冠长增大而减小,两者之间存在紧密的相关关系,把相对冠长作为辅助因子,配合树高建立形数预测模型,按立木材积三要素测定材积,可在不测上部直径的情况下,有效地提高立木材积的测定精度。