ANALYSIS OF RECENT MEASUREMENTS OF THE VISCOSITY OF GLASSES.—II1

Viscosity of two series of four component glasses .—The results recently reported by S. English² are here analyzed by the method used in a previous paper.³ (1) Series 6SiO₂, 1.2Na₂O, 0.8(CaO+MgO). The temperature at which the difference between the viscosity of a glass and the viscosity of 6SiO₂,2Na₂O at the same temperature makes a sharp bend is called the aggregation temperature Ta . It seems to correspond to the devitrification temperature. For this series Ta reaches a sharp minimum for the composition 6SiO₂, 1.15Na₂O, 0.45MgO, 0.39CaO. The viscosity for any temperature also reaches a minimum at or near this composition. (2) Series 6SiO₂, 1.1Na₂O, 0.9(CaO+Al₂O₃). The curves are similar to those for the first series, TA reaching a sharp minimum for the composition 6SiO₂, 1.11Na₂O, 0.81Ca0, 0.14Al₂O₃.     

METHOD FOR THE STUDY OF THE RELATIVE VISCOSITY OF ENAMEL GLASSES1

A method has been developed by which the flow characteristics of vitreous enamel glasses may be conveniently studied. The apparatus and method are described. Typical results are illustrated both by photographs and by a chart based on planimeter measurements of area of flow.     

VISCOSITY OF RECENT CONTAINER GLASS*

A high-temperature, concentric cylinder viscometer has been constructed and calibrated. The calibration checks within 1% that obtained by Lillie for a similar apparatus and provides further evidence of the high degree of reliability of this type of measurement. The contention of Washburn and Shelton that the calibration in such instruments is a function of the viscosity is shown to be false. Because four independent investigations have been unable to check this contention, it may now be regarded as spurious. A medium temperature-range fiber viscometer for measuring the viscosity of glass in the annealing range has also been constructed. It is shown that the Fulcher equation, log η=−A+B/T−T₀, fits the data obtained on the two instruments to within 0.5% for commercial soda-lime glasses. Complete viscosity data as a function of temperature are given for sixteen commercial container glasses, and the analyses are also included. These glasses show a wide range of viscosity.     

PRECISE MEASUREMENTS OF THE VISCOSITIES OF GLASSES AT TEMPERATURES NEAR THEIR ANNEALING POINTS*

The paper describes a new apparatus for measuring glass viscosities of 10¹³ poises and higher. It consists of causing the glass flow to take place inside a steel tube by means of air pressure. The amount of flow is observed by means of interference fringes between the top of the glass sample and a stationary plate of fused silica. Preliminary experiments with two glasses, a lime and a light flint, are described and the results given. A comparison is also made between results by this method and by that of fiber elongation. The new results indicate that the apparatus can he successfully used for observing flow-pressure relations at extremely high viscosities and also that at the temperatures used these two glasses are purely viscous liquids.     

一点法求聚丙烯酸的特性粘数

测定了聚丙烯酸和丙烯酸／甲基丙烯酸－β－羟乙基酯的特性粘数,比较了用九个经验式求得的特性粘数差异,指出了实验体系的Ｈｕｇｇｉｎｓ常数ｋ’较大是造成部分计算结果偏差较大的原因,提出了一个ｋ’取０．６４的简易一点法公式 。用该公式计算的２４个数据中的,相对偏差小于１％的数据为１２个,好于用已知九个公式计算的结果。     

THE TEMPERATURE COEFFICIENT OF VISCOSITY AND ITS RELATION TO SOME OTHER PROPERTIES OF LIQUIDS AND GLASSES*

A possible connection between the temperature coefficient of viscosity (not the viscosity itself), the latent heat of fusion or some similar work-function, and the absorption spectrum of liquids and glasses is discussed. The three things seem to be connected in a fairly clear and simple manner. It is shown, for instance, that from viscosity data alone it is possible to predict the position of the ultra-violet absorption band in glasses, and the black color of pitch. Also, that at high temperatures the ultra-violet absorption band invades the visible spectrum and migrates down into the infra-red, and that at room temperature the viscosity of typical soda-lime-silica glasses is of the order 1070 poises. A meaning is attached to the term “viscosity” at temperatures at which it can not be measured mechanically, and a means of tracing it optically down to absolute zero is suggested.     

ON A NEW LIGHT-SOURCE FOR ABSORPTION MEASUREMENTS OF GLASSES IN THE BLUE AND ULTRA-VIOLET1

On metallic thorium, when bombarded with cathode rays, a blue glow may be observed in high-vacuum as well as in gas-filled tubes. The spectrum of this phenomenon is continuous, the maximum of intensity being (according to photograph determinations) at 4.500 Å. The spectrum has been observed from A000 to 2200A. Lamps making use of the emission of the blue glow on thorium are described and their spectra discussed. It is shown that the new light-source has several advantages in comparison with other light-sources now in use.     

EXPANSION MEASUREMENTS OF SEVERAL GLASSES BY MEANS OF A SELF-REGISTERING APPARATUS1

Applying an apparatus which registers photographically, and using quartz glass as control material, the expansion behavior of several glasses upon heating to temperatures above the softening point was investigated. It is shown that, with the help of the arrangement developed, even slight variations in the expansion-temperature curve, which might easily escape visual observation, can be detected. It is possible, by utilizing the results of these measurements, to regulate the annealing process of the glasses in the most useful manner.     

二元钾硅酸盐玻璃结构的Raman光谱分析

用带空间分辨和累积时间分辨耦合系统的Raman光谱仪,测定了二元钾硅酸盐K2O·xSiO2玻璃及晶体的Raman光谱,比较并解释了随SiO2含量变化的微结构单元Raman振动模。结果表明:钾硅酸盐玻璃有多种微结构单元共存,并且随二氧化硅含量的增加,微结构逐步由硅氧四面体单体向二聚体、链状、层状和网络状转化。硅氧四面体对称伸缩振动区的主峰不对称性以及展宽主要是由于一系列具有不同微环境下的二级结构的变化造成的。微环境的不同是造成精细微结构单元和光谱表征差异的根本原因。Raman光谱的精细结构反映了微结构单元连接的复杂性,采用二级结构的概念有利于在更深层次和更大的空间范围内来认识硅酸盐玻璃微结构。     

硅酸盐玻璃的风化

综述影响浮法玻璃、压延玻璃、光学玻璃、晶质玻璃和器皿玻璃的耐风化性因素，风化产物的形貌和风化过程。导出了玻璃表面风化析碱量和环境条件如温度、湿度和时间的关系：玻璃样品的析碱量随风化温度、湿度和时间而增加。风化产物的形貌和成分用SEM，WDS，EPMA和XPS来检测。结果表明：钠钙硅酸盐玻璃风化表面产物主要为钠和钙的碳酸盐。如玻璃发生分相，玻璃的耐风化性不仅与玻璃成分有关，还与分相形貌有关。富硅滴状结构易风化，风化程度随富硅相液滴的数量而增加。在相同条件下，富硅相的连通结构降低玻璃的风化程度。还阐述了玻璃风化机理及如何防止风化的方法，并对改善玻璃耐风化性指出了研究方向。     

水煤浆黏度的几种影响因素分析

研究了矿物质、粒度分布和搅拌强度对水煤浆黏度的影响.结果表明,实验使用的3种矿物质——高岭土、氧化铝和碳酸钙在降低水煤浆的黏度方面效果都比较明显,其中高岭土最显著,可以使黄陵水煤浆的黏度降低59.5%左右.适当的粒度级能有效改善浆体黏度,剪切率为116.5s-1时,枣庄煤级配制备的水煤浆的黏度值在820mPa·s~900mPa·s之间,而神准混煤级配制备的煤浆黏度值更低,处于500mPa·s~670mPa·s之间.同时搅拌强度的增加在一定范围内可以有效降低煤浆的黏度.     

ON THE DETERMINATION OF THE CONSTITUTION OF GLASSES1

This method of determination of the constituents of glasses is entirely new in its way. It is derived from the author's experiments on the causes of the surface devitrify-cation of glasses. It is quite natural to produce crystals in glasses when heated several times at high temperatures. The glasses are super cooled liquids and are very viscous at low temperatures. But, when they are heated at higher temperatures, they attain low viscosities to produce crystals in them. In general, the chemical composition of the crystals produced (primary phase) in ordinary glasses without B₂O₂ is SiO₂. And for production of an elementary body of crystals of silica, there should be at least three neighboring molecules of silica moving within some ranges of speed. The motion of such molecules in glasses is set by two causes: the one is that quantity of energy given to the molecules by heating, and the other is that lowering of viscosity of the medium by heating. Heating glasses to certain temperatures is the exclusive cause of the crystal production of glasses. This has been already explained by many persons and no ambiguity has been left unsolved. The author has given another important cause for crystal production on glass surfaces and has described the interpretation. ³ 1 Received August 11, 1926.
From these views, the author has arbitrarily defined devitrify-cation in five degrees. They are seen in accompanying photographs. It has been determined that these degrees of devitrify-cation were entirely coincident with the quantities of dissolved silica in glasses. The experiments have been conducted for a series of glasses of alkali silicates and alkali lead silicates. From the results of these experiments, the author has determined the constitutions of those silicates in glasses to be meta-disilicates and the double compounds to consist of those meta-disilicates. As the result of the determination of the constituents of alkali silicates and of alkali lead silicate glasses, it is pointed out that the compositions of crucibles to melt glasses of different silica content, should be either rich Al₂O₃: or rich SiO₂ according to the dissolving power of glasses for silica.     

Tb3+掺杂Faraday磁光玻璃的研究进展

Tb^3 掺杂Faraday磁光玻璃是一种新型的功能材料，在光纤通信和传感领域有广阔的应用前景。综合介绍了磁光玻璃Faraday效应的基本原理。Tb^3 掺杂Faraday磁光玻璃的Verdet常数是电子有效跃迁波长λt，有效跃迁几率Ct，单位体积内的顺磁离子数N和绝对温度T等参数的函数，同时还受到基质玻璃的影响。虽然Verdet常数越大、磁光效应的灵敏度越高，但是应该在保证磁光玻璃综合特性和改进热稳定性和化学稳定性的基础上提高Verdet常数。     

THE DEVITRIFICATION OF SODA-LIME-SILICA GLASSES1

The isotherms and boundary curves in that portion of the ternary system Na₂O-SiO₂–CaO.SiO₂–SiO₂ of direct application to glass technology, namely, from 64 to 78% SiO₂, 0 to 20% CaO, including the whole of the field of the compound Na₂O.3CaO.6SiO₂, and portions of the adjoining fields of Na₂O.2SiO₂, Na₂O.2CaO.3SiO₂, CaO.SiO₂, tridymite, and quartz, have been determined with greater precision than in a previous study² by greatly increasing the number of mixtures studied, and thereby decreasing the interpolation necessary in the interpretation. An extended discussion is given of the devitrification of glass, in which it is shown that the liquidus temperature is the only datum point which is solely a function of glass composition, and is unaffected by the past history of the glass or by fortuitous circumstances at the time devitrification is taking place. At the liquidus the first trace of crystalline phase is in equilibrium with the glass; above the liquidus the glass will dissolve any such crystals which may have been formed at some previous time, but new crystals cannot form; while only below the liquidus is there a tendency for crystals to separate. The driving force causing this reaction is derived from the difference in free energy between the unstable glass and the stable aggregation of crystalline phases, and this force is opposed by a resistance of the nature of a viscosity. The dissociation in the liquid phase of the compounds which separate on devitrification diminishes the rate at which the devitrification equilibrium is reached, and increasing the complexity of the glass will have a similar effect. The excess in surface energy at the interface glass-crystal may have an influence at the instant of formation of the first infinitesimal crystal, hut after the crystal has grown to a dimension appreciably greater than the sphere of molecular action the excess energy at this interface ceases to be of importance. The only surface tension measurements which have been made on glass refer to the interface glass-air, and the excess energy at this interface has no necessary correlation with the devitrification process.     

聚合物粘度的测量标准及特性粘数的获得

介绍粘度测量的一般思路，列举出测量粘度的标准名称，简要叙述了高分子溶液特性粘数的获得方法。     

ON THE CAUSES OF THE SURFACE DEVITRIFICATION OF GLASSES1

The explanation on the causes of the surface devitrification of glasses upon heating, as heretofore considered, is imperfect. The modes of surface devitrification are greatly influenced by the surface conditions of the glasses. The author gives an interpretation on the causes of this phenomenon of surface devitrification, i.e., the surface contraction which is caused by the surface tension at the glass surface acts most seriously toward the surface devitrification.     

风电叶片用结构胶粘剂粘度及触变性试验分析

风力发电是结构胶粘剂的新兴应用领域,在风电叶片的生产、组装、部件制造中有着广泛的应用,是风电叶片整体结构中的关键组成。有效地分析评价风电叶片用结构胶粘剂对于保证叶片的质量极为重要。胶粘剂的流变性是评价其质量和工艺性能的关键因素,其中粘度和触变性是两个极为重要的表征量。通过对风电叶片用结构胶粘剂在不同测试条件下的粘度和触变性试验,总结不同测试条件对胶粘剂粘度及触变性评价的影响,并提出使用触变环法评价结构胶粘剂的触变性的方法。经过分析表明,触变环法能够定性定量地表征胶体的触变性。