【作者】 刘丽敏；

【导师】 庄寿增；

【作者基本信息】 南京林业大学 ， 木材科学与技术， 2008， 硕士

【副题名】平板玻璃毛细管液体张力测试模型的构建与测量

【摘要】 木材细胞皱缩的动力学机制是木材皱缩机理研究的核心问题之一。本文是国家自然科学基金项目“木材细胞皱缩源动力及其形成机制研究”的组成部分。本文是在庄寿增等人的研究工作基础上,主要对平板玻璃毛细管液体张力测试模型构建过程中需要解决的相关问题作进一步研究和分析讨论。首先研究了构成平板玻璃毛细管组件的相关表面特性。应用光学原理对平板间水膜形成的干涉条纹变化等进行了试验研究,为选择理想的玻璃试件提供理论依据和简捷的方法;用分析天平秤重法测量了平板玻璃毛细管水膜的平均厚度;悬滴法和量角法测量了平板玻璃与纯水和乙醇的接触角。然后在庄寿增等设计的实验基础上,初步摸索出一种较规范的试验方法,首次用电子万能试验机测量平板玻璃毛细管液膜张力,并分别用两种粗糙度(浮法和光学)的平板玻璃和两种表面张力液体(纯水和分析纯乙醇)作张力测量。结果表明,平板玻璃毛细管内液膜产生的拉张力不遵循经典的“杨-拉普拉斯”定律。最后,本文设计了一种采用压力传感器直接测量平板玻璃毛细管内液膜张力的测试装置,分别对纯水和汞的小液滴压力和液体张力传递过程作直接测量,结果表明平板玻璃毛细管凹凸液面表面张力产生的附加压强同样不遵循“杨-拉普拉斯”定律。以上初步研究结果对木材皱缩的源动力来自于毛细负压强的传统观点提出了质疑。更多还原

【Abstract】 The wood cells collapse source dynamic is one of the core issues about the research on the mechanism of wood collapse. This paper is a part of the project which the research on the source dynamic and formation mechanism of wood cells collapse, is supported by National Nature Science Fund Project. On the basic of the foregoing research by Shouzeng Zhuang et al., this paper primarily was worked about some tests on measurement to liquids tensile force produced in flat plate glassy capillary column modeling, and studied on the correlated issues about constructing the model, made a further investigation and analysis.Firstly, some research on the material surface property was done. Applications in the optics theory, made some experimental researches on the water films middle in duplet flat plate glassy, the films form interferometric fringes. The experiment is used in choosing the best surface flatness coarseness with the mini flat plate glassy module, for offering theories foundation and sums shortcut methods for the above research. We applied analyses legalists method measuring flat plate glassy capillary column-water films and got an average thick of the water films. Measured contacting angles formed between the double-flat plate glassy with purified water and ethyl alcohol.Secondly, on the basis of designed experiments by Shouzeng Zhuang et al., this paper elementarily proposed one kind of better measurement approach. In this paper, the adoption of electrons omnipotent test machine measuring the fluid films tensile force process of formation in the double-flat plate glassy capillary column, this method is the first time adopted. Two different kinds of surface roughness flat plate glassy and two different surface tension liquids (purified water and analyses purely ethyl alcohol) were adopted as material of tensile force measurement. The all results indicated that liquid films is produced in the interior of the double-flat plate glassy capillary column tensile force, its rule is not to follow the traditional“Young-Laplace equation”exactly.Finally, in this paper, one measurement unit was designed, adopted pressure sensor to directly measure interior liquid films of the double-flat plate glassy capillary column. Separately in this test directly measured mini liquid drops of purified water and mercury pressure and liquids tensile force and their transportation processes. The results indicated that flat plate glassy capillary column concave or convex liquid surface tension produce negative intensity of pressure dose not follow“Young-Laplace equation”as well.These results preliminarily showed that the research on the dynamical source of lumber cell collapse which is insighted from capillary negative intensity of pressure is doubted. The conventional viewpoints is putting forward doubting.更多还原