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液体折射率是重要光学参数之一,液体折射率参数测量在食品生产鉴定、光学加工等领域都具有重要意义。本文基于便携式迈克尔逊干涉仪,在光学减震台上加装旋转微调载物台,综合考虑旋转后容器器壁、待测液体、空气中光程差的改变量,得到液体折射率的计算公式,与阿贝折射仪测量液体折射率的值进行比较,实验测得水、不同浓度的葡萄糖溶液以及不同浓度的氯化钠溶液,平均相对误差分别为1.1%、3.3%、2.0%,实验过程中测量的最大误差为5.9%,为液体折射率测量提供了一种可行方法,实现液体折射率的测量。本文也可作为迈克尔逊干涉仪的拓展实验,对本科生的创新能力培养有重要意义。 相似文献
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旋转液体的物理特性研究是新世纪大学生必修实验。学生在实验操作过程中出现的实验误差,直接影响本实验对于重力加速度的测量。本文创新性地进行了不同类型的实验误差下重力加速度测量准确度的理论推导,从而定量地分析了在实验过程中透明屏幕偏离水平位置角度α、激光垂直入射点位置偏移量Δx和激光入射方向偏离垂直方向角度γ等因素对重力加速度测量准确度影响规律。分析结果表明:透明屏幕偏离水平位置5°会引起5.5%的误差;激光垂直入射点向左偏离目标点x0处5 mm会引起12.5%的误差,激光垂直入射点向右偏离目标点x0处5 mm会引起11.8%的误差;激光入射方向向左偏离垂直方向5°会引起16.3%的误差,激光入射方向向右偏离垂直方向5°会引起22.9%的误差。该研究可为高校教师指导学生进行旋转液体特性实验时减小重力加速度测量误差提供理论依据。 相似文献
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红外光谱分析中样品处理方法的改进 总被引:4,自引:0,他引:4
介绍了液体和固体样品的常规制样方法 ;指出了其中最常用的方法———压片法和液膜法的不足之处 ;提出了一种改进的制样方法 ,即以廉价的空白KBr压片作片基 ,通过液膜法或浸渍法制样。对于低沸点液体样品 ,以两片空白KBr压片代替晶体盐窗 ,模拟液体池窗片液膜法制样 ;对于高沸点液体样品 ,将样品用挥发性有机溶剂稀释 ,采用浸渍法制样 ,即把空白KBr压片在稀释后的溶液中浸渍后挥发掉有机溶剂制样 ;对于固体样品 ,将其溶解于挥发性有机溶剂 ,浸渍法制样。与按常规制样方法所获得的红外光谱图进行比较 ,这种改进的制样方法所得谱图 ,能达到定性分析的要求 ,且弥补了常规液膜法和压片法的不足 相似文献
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This study presents an application of ultrasonic technology in the high voltage liquid insulation domain towards the reduction of pour point of vegetable oil samples for the utilization of vegetable oils as liquid insulation in cold climate areas on power transformers. Pour point reduction has been achieved by processing the vegetable oil samples by using ultrasonic treatment process with 100 W and 30 kHz ultrasonic waves for various exposure times of 15, 30, 45 and 60 min. Edible vegetable oils such as sunflower oil, palm oil, sesame oil and non edible vegetable oils such as honge oil, neem oil and punna oil are considered as two categories of vegetable oils for this experimental investigation. Ultrasonic treatment process results in the reduction of pour point of vegetable oils to meet out the standard value of pour point for liquid insulation as per IEEE Standard C57.147, 2018. A significant reduction in pour point temperature of vegetable oil samples have been obtained with an increased exposure time. The obtained variations in pour point after exposure with ultrasonic waves may be due to the possible changes in crystallization kinetics of fatty acids components of vegetable oil samples due to energy input of ultrasonic waves. The experimental results have given a way towards the positive encouragement and development with ultrasonic treatment for achieving low pour point vegetable oils as liquid insulation in power transformers for applications on cold climatic areas. 相似文献
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Lü XiaoQian BIAN XiuFang XIANG Nan & JIA Ran Key Laboratory for Liquid-Solid Structural Evolution Processing of Materials Sh ong University Jinan China 《中国科学:物理学 力学 天文学(英文版)》2010,(3)
The atomic structures of liquid Ag-based binary alloys have been investigated in the solidification process by means of X-ray diffraction. The results of liquid structure show that there is a break point in the mean nearest neighbor distance r1 and the coordination number Nmin for glass-forming liquid, while the correlation radius rc and the coordination number Nmin display a monotone variational trend above the break point. It means glass-forming liquids have a steady changing in structure above liquidus a... 相似文献
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We study here a mean field model to obtain the phase diagram (concentration versus temperature) near the NAC* point in a binary mixture of liquid crystal. We have fitted our phase line equations to the experimental data for the mixture of SCE9 + SCE10 liquid crystals. We deduce from our analysis that there should exist a tricritical point close to the NAC* point on the AC* phase line. 相似文献
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F. J. Baltá-Calleja K. D. Berling H. Čačković R. Hosemann J. Loboda-čačković 《Journal of Macromolecular Science: Physics》2013,52(3):383-392
Experimental values for the diamagnetic susceptibility of a series of mono-disperse n-paraffins ranging between 6 and 50 carbon atoms in the solid (melt and solution crystallized) and in the liquid state are reported. From the dependence of the molecular susceptibility, ScHM, on the molecular weight, information about the intermolecular interactions between adjacent chain molecules and on the arrangement of the methyl end-groups is obtained. The ScHM values of melt- and solution-crystallized paraffins are, within experimental error, indistinguishable from each other. For C12H26 and C44H90 the specific susceptibility ScHM /M rises at the melting point within a few °C and reaches a plateau which characterizes the liquid state II. For the paraffin C24H50 an intermediate plateau between the melting point and the final true liquid state is observed and is called liquid state I. After cooling below the melting point TM, the ScHM value of the equilibrium state can be obtained after a short time only from liquid state I, while from liquid state II days and weeks are needed for this. By combining this information with the observed ScHM values, it is concluded that in liquid state I a higher or smectic-like order exists similar to mesophases, well-known in liquid crystals, while in the real liquid state II this order is lost. 相似文献
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本文以乙醇-甲酰胺,乙腈-甲酰胺,乙醇-环己酮,乙腈-环己酮四种混合溶液为研究对象,采用激光拉曼光谱对四种溶液体系的闪点行为进行讨论和研究。通过测定四种溶液体系的拉曼光谱和闪点,结合溶液拉曼光谱的特征峰强度比和拉曼位移的变化,探索四种溶液闪点的变化规律。试验结果表明,随着溶液浓度的增大,溶质的拉曼特征峰强线性增加,混合溶液的闪点降低。采用三次多项式分别对四种溶液体系的闪点与拉曼特征峰、溶液浓度的关系进行拟合,拟合结果良好。混合溶液的闪点随拉曼特征峰强比、溶液浓度的变化趋势相同。该试验方法将有助于从分子结构角度分析混合溶液的闪点变化规律,同时该方法可用于混合溶液闪点的实时在线检测。 相似文献
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《Physica A》1991,174(1):139-148
A system of binary mixtures of two liquid crystal compounds is prepared possessing a tricritical point in the smectic A-ferroelectric smectic C transition line in the temperature-composition plane. In several mixtures with different distinctness of the first-order nature of the transition the approximate coordinates of the electric-field-induced critical point, at which the first-order transition vanishes, are determined by measurements of the electric displacement. The critical field strength and the temperature difference between the transition at zero field and the critical point shrink to zero as the tricritical point is approached. This is the first study of the wing critical points of a tricritical point in liquid crystal phase transitions. 相似文献
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We point out that the quasiparticle spectrum of the Landau Fermi liquid theory has an extra Z2 symmetry, local in momentum space, which is not generic to the Hamiltonian with interactions. Thus the Fermi liquid is in this sense a (quantum) zero-temperature critical point. 相似文献