离子交换玻璃平板和圆棒中的氧化钠浓度和折射率分布

用有限差分法解扩散系数依赖于浓度的扩散方程。将计算的离子交换玻璃平板和圆棒中的氧化钠浓度和折射率分布分别与用电子探针和干涉显微镜测量的结果做了比较。即使玻璃中离子的互扩散系数还取决于长的离子交换时间,若通过选择某一时间离子交换玻璃中离子的互扩散系数,去计算其他时间离子交换玻璃中的浓度和折射率分布,可以使计算值和测量值之间的误差降低到尽可能小。在计算机模拟的基础上,讨论了计算参数和玻璃棒半径大小对获得最佳折射率分布时的离子交换时间的影响。     

Increase in the refractive index of alkali titanium-hafnium silicate glass upon Na+ (glass)-Li+ (melt) ion exchange

An increase in the refractive index upon ion exchange in the Li₂SO₄ + Li₂MoO₄ salt melt has been studied for glasses of composition (mol %)xLi₂O-(25 -x)Na₂O-15TiO₂-6HfO₂-54SiO₂, wherex = 0, 5, 10, 15, 20, and 25. The ordinary transparent single-layer and two-layer diffusion zones are obtained. In the latter zone, the optically opaque near-surface layer gives way to a deeper optically transparent layer with the refractive index gradient. The opaque layer produced by the low-temperature exchange exhibits a unique structure, which is permeable to melt. An increase in the refractive index as large as 0.055 is achieved for the first time without fracture and crystallization of glass.     

Increase in the refractive index of alkali titanium-hafnium silicate glass upon Na+ (glass)-Li+ (melt) ion exchange

An increase in the refractive index upon ion exchange in the Li₂SO₄ + Li₂MoO₄ salt melt has been studied for glasses of composition (mol %)xLi₂O-(25 -x)Na₂O-15TiO₂-6HfO₂-54SiO₂, wherex = 0, 5, 10, 15, 20, and 25. The ordinary transparent single-layer and two-layer diffusion zones are obtained. In the latter zone, the optically opaque near-surface layer gives way to a deeper optically transparent layer with the refractive index gradient. The opaque layer produced by the low-temperature exchange exhibits a unique structure, which is permeable to melt. An increase in the refractive index as large as 0.055 is achieved for the first time without fracture and crystallization of glass.     

Influence of diffusion nonlinearity on the characteristics of gradient-index diffractive structures formed in glasses by ion-exchange technique

The influence of the diffusion nonlinearity on the formation of gradient-index diffractive structures by the low-temperature silver ion-exchange method (including electroinduced ion exchange) has been studied for two glasses (light crown type) with the same glass-forming matrix and different alkali compositions. One glass containing only sodium shows the anomalous nonlinearity, and another glass with mixed lithium-sodium composition is characterized by the normal nonlinearity. The silver-sodium exchange in both glasses leads to the same refractive index increments. The simulation of gradient-index diffraction gratings in these glasses demonstrates that the diffusion nonlinearity strongly affects the maximum phase modulations and diffraction efficiency of gradient-index gratings. It is shown that the most efficient diffractive structures can be obtained for glasses with the anomalous diffusion nonlinearity, all other factors being the same.     

Influence of diffusion nonlinearity on the characteristics of gradient-index diffractive structures formed in glasses by ion-exchange technique

The influence of the diffusion nonlinearity on the formation of gradient-index diffractive structures by the low-temperature silver ion-exchange method (including electroinduced ion exchange) has been studied for two glasses (light crown type) with the same glass-forming matrix and different alkali compositions. One glass containing only sodium shows the anomalous nonlinearity, and another glass with mixed lithium-sodium composition is characterized by the normal nonlinearity. The silver-sodium exchange in both glasses leads to the same refractive index increments. The simulation of gradient-index diffraction gratings in these glasses demonstrates that the diffusion nonlinearity strongly affects the maximum phase modulations and diffraction efficiency of gradient-index gratings. It is shown that the most efficient diffractive structures can be obtained for glasses with the anomalous diffusion nonlinearity, all other factors being the same.     

A Method for Determining the Equilibrium Straight Line of the Refractive Index of Glasses by Two Points

A method is devised for determining the equilibrium straight line of the refractive index of glasses by two points in the temperature dependence of the refractive index of thin quenched samples. The time required to obtain data by the proposed method is seven- to tenfold shorter than that required by the standard method.     

Thermal history and its implications: A case study for ion exchange

Glasses containing monovalent species can be chemically strengthened by the replacement of smaller ions in the glass with larger external ions in the near glass surface. This type of ion exchange puts glass surface under high compressive stress (CS). Glass mainly fails from tension with the presence of surface flaws. Chemical strengthening can change the stress at the flaw tip from tension to compression and further stop the flaw from propagating. Glass damage resistance is therefore significantly improved. For the same glass composition, glass thermal histories can affect the magnitude and depth of the CS generated during ion exchange. In this study, the impact of thermal history on glass physical properties and ion exchange attributes in one alkali-containing glass formed by fusion draw process was investigated. Multiple thermal treatments were done to rewrite the glass thermal histories. Glass density, refractive index, and ion-exchange properties as a function of the thermal treatment were studied. It is concluded that ion exchange-related properties change dramatically with the glass thermal history.     

头孢菌素C锌盐含锌母液的回收及处理研究

利用化学沉淀法和离子交换树脂法处理头孢菌素C锌盐废液中的锌离子,确定了化学沉淀法的适宜条件和离子交换树脂处理后废液直接排放的可行性研究。     

Development of a Spectrophotometric Biphasic Assay for the Estimation of mPEG-maleimide in Thiol PEGylation Reaction Mixtures

Methoxy(polyethylene glycol)-maleimide (mPEG-mal) is a PEG derivative used for thiol PEGylation of protein molecules and finds application in drug delivery studies. The maleimide group undergoes degradation in aqueous media, resulting in the difficult quantitative analysis of mPEG-mal. Routinely employed methods for separation and estimation of mPEG-mal include tedious chromatographic methods like ion exchange, high-performance liquid chromatography with refractive index detector and techniques like mass spectrometry and proton nuclear magnetic resonance. We present a direct and reproducible spectrophotometric method to quantify free and protein bound mPEG-mal in thiol PEGylation reaction mixtures. This method is based on the partitioning of a PEG bound chromophore between an aqueous ammonium isoferrothiocyanate phase to a chloroform phase in the presence of mPEG-mal. Several important parameters influencing the partitioning and stability of the chromophore, volume ratios of liquid phases, ethylenediaminetetraacetic acid concentration in the reaction mixture, mixing time, and chlorinated solvents used for partitioning have been studied.     

Structural relaxation dynamics of a silicate glass probed by refractive index and ionic conductivity

Relaxation occurs spontaneously in all glasses and is a fundamental step of important technological processes, such as annealing, crystal nucleation, and chemical strengthening by ion exchange. Despite extensive studies over the past decades, there are still conflicting results on whether the kinetics of structural relaxation depends on the analyzed property. Thus, in this study, we used a lithium disilicate glass as a model composition to determine the structural relaxation kinetics during physical aging experiments by measuring the time evolution of the refractive index and ionic conductivity down to 35 K below the initial fictive temperature. In all cases, variations in these properties were adequate to capture the structural changes throughout the aging experiments. At each temperature, the experimental relaxation data fit quite well with the classical stretched exponential relation. We also found that the relaxation process starts faster when probed by ionic conductivity than by refractive index; however, they show similar average relaxation times. These very small structural rearrangements are always the same, but ionic conductivity changes faster than refractive index at the beginning of the process. Our comprehensive results strongly indicate that relaxation dynamics is indeed dependent on the analyzed property.     

5万t/a离子膜烧碱装置试车及运行情况总结

齐鲁石化股份有限公司氯碱厂引进意大利迪诺拉公司5万t/a离子膜法烧碱装置,顺利完成72h性能考核交付生产,1年来生产状况良好,产品质量稳定,工艺技术指标始终控制在最佳状态。介绍了试车过程中引进装置、国内配套装置存在的问题及解决办法。尤其详细介绍了开停车情况,盐水过滤系统、树脂塔、淡盐水脱氯系统及电解槽运行情况;提出要严格控制进槽盐水质量,加强对离子膜电槽的运行管理,认真学习离子膜法制碱技术,以确保离子膜电解槽安全稳定运行。     

An Increase in the Refractive Index of a Multicomponent Silicate Glass by Six-Hundredths upon the Na+glass–Li+meltIon Exchange

An increase in the refractive index of the glass surface by n= 0.06 after the Na⁺ _glass–Li⁺ _meltion exchange is obtained for the first time.     

用在线微型柱连续测定系统研究弱阳树脂的交换性能

用FIA-ISE测定痕量钠离子的系统与在线微型柱结合,考察了在动态条件下影响弱酸性阳离子交换树脂的交换性能的因素,得到了测定其交换容量的最佳参数:微型柱树脂填充量0.1762g(层高45mm),温度33℃,样品水为10mg/L钠离子溶液(NaOH),样品水流量0.92mL/min,再生剂HCI用量40mL,再生剂流量1.25mL/min,再生剂浓度4.0%(逆流再生).在最佳条件下,利用本方法对不同厂家的大孔型弱阳树脂(D113)的交换性能进行了测定和比较.本方法实现了一次测定同时获得弱阳树脂的平衡交换容量、全交换容量、转型膨胀率和树脂利用率等多个指标,并与GB法进行对比实验,发现了二者具有良好的相关性(r=0.9904).     

Preparation of antireflection coatings from silicon dioxide on glass and quartz by the sol-gel method with oligoethers

Antireflection coatings with a low refractive index (1.18–1.23) have been prepared on silicate glass and optical quartz from mesoporous silicon dioxide synthesized by the sol-gel method in the presence of oligoethers. The optimum concentration of the oligoester in the sol is equal to 1.5–2.5 wt %. For the single-layer double-sided coating, the maximum transmission is equal to 99.0% for the silicate glass and 99.9% for quartz.     

001×7钠离子交换树脂工作性能的测定及其意义

001×7钠离子交换树脂的一个重要指标是工作交换容量,但它随着工作条件的不同而不同。作者研究了钠离子交换树脂实际工作性能测定方法,通过建立实验室标准测定工作条件,其中对测定树脂的预处理方式、软化器参数、进水水质及终点控制、运行流速等四个方面进行条件优化后定为标准测定条件,并与标准树脂进行对比实验形成简易鉴定树脂工作性能的新方法。该方法可广泛用于树脂工作性能和中毒情况的鉴定以及水处理设计等方面。     

Resonant Optical Nonlinearity in Vitreous Semiconductors

Upconversion pumping of rare-earth ions in a semiconductor optical medium under particular conditions leads to an increase in the refractive index. The mechanism of the effect observed implies that, upon double or triple excitation by photons with energies less than the band gap, the energy of an Er³⁺ ion becomes sufficiently high for interband generation of free carriers. The resonant internal photoeffect is responsible for the increase in the refractive index.     

Theoretical Aspects of the Ion Exchange in the Fabrication of Focusing Gradient-Index Lenses

An expression relating the refractive index at different points of the gradient region of an axially symmetric ion-exchanged gradient-index element to the concentration of the component incorporated into the glass from the salt melt is derived and analyzed. It is demonstrated that the radial distribution of the refractive index gradient in a focusing gradient-index element is described by an even function symmetric about the ordinate axis with a local minimum on it and two side maxima in the surface region of the cylinder. This provides an explanation for the origin of the surface “tails.” A theoretical relationship is obtained using the metric of the equilibrium chemical diagram. The correctness of this relationship is verified for the case of the exchange between lithium ions from an alkali borosilicate glass and sodium ions from the salt melt, as well as for the case of the exchange between thallium ions from a thallium borosilicate glass and potassium ions from the salt melt.     

Refractive index of alcohol nonionics

Refractive index is a rapid and consistent method of analysis for alcohols and nonionics from normal alcohols and ethylene oxide. Correlations of refractive index with hydroxyl number of alcohols and nonionics are excellent and measurement error is considerably lower for refractive index. Refractive index affords a measurement of the amount of ethylene oxide in nonionics and can be used as a replacement for the 1% cloud point analysis. The ethylene oxide adduct distribution has no effect on refractive index. Specific adducts, a narrow range of adducts made by acid catalyzed ethoxylation and a broad range of adducts made by base catalyzed ethoxylation give the same refractive index value for any given ethylene oxide content. Applications for the refractive index method for the laboratory and plant are: alcohol blending control, calculation of ethylene oxide requirements for ethoxylation, nonionic control analysis, calculations of hydroxyl number for sulfations. Also, refractive index can help identify laboratory samples, indicate the 1% cloud point and predict the phase character of nonionics.     

双柱交换法提取赖氨酸工艺研究

探索离子交换技术提取高纯度赖氨酸的工艺方法,考察离子交换液的pH,离子交换树脂型号的选择,流量,解析剂浓度等因素的影响,并采用低浓度弱碱预洗上柱液,寻找提取高纯度赖氨酸的适宜条件.     

多孔SiO2膜的制备和增透性能研究

采用溶胶-凝胶结合旋转涂膜法在玻璃基底上制备SiO2薄膜,研究了陈化时间和旋涂速度对SiO2膜增透性能的影响,利用热分析仪、X射线衍射仪、红外光谱仪、扫描电镜、分光光度计、椭偏仪等方法分别对干凝胶的热分解过程、晶体结构、微观形貌、透过率和折射率进行表征.结果表明:膜层透过率与制备条件有一定的规律,随着陈化时间的延长和旋涂速度的增加,增透峰中心波长发生了移动.在最佳工艺条件下,制备的SiO2薄膜具有较好的增透性能,在玻璃上镀SiO2增透膜后,峰值透过率(300～1000 nm)由90％提高到95％,其膜厚为315 nm,折射率为1.352,孔隙率为27％,进一步提高了可见光利用率.