Water-soluble UV curable urethane methyl acrylate coating: preparation and properties

Two kinds of water-soluble and ultraviolet (UV) curable oligomers were synthesized and characterized. The oligomers were evaluated as resins for water-based UV curable coating. The rheology of the two oligomers' aqueous solutions was investigated in terms of solid fraction, pH dependence, and temperature dependence. The solutions were found to be Newtonian fluid showing rather low viscosity even at high solid fraction of 0.55. The drying process of the coatings and the properties of the cured coatings were studied by comparing them with water-dispersed UV-curable polyurethane methyl acrylate. It was evident that the water-soluble coating dried more slowly; and that the overall properties were inferior to those of the water-dispersed coating.     

分光光度法测定山香圆片中黄酮的含量

采用不同溶剂经超声、微波、热回流三种方法提取山香圆片,以芦丁为对照品,用分光光度法测定总黄酮含量.结果表明:以70%乙醇作溶剂,回流3h的条件下,黄酮的提取量最高.     

In-situ production of ozone and ultraviolet light using a barrier discharge reactor for wastewater treatment

A dielectric barrier discharge （DBD） reactor consisting of water-filled dielectric tube electrodes was used for the treatment ofwastewater. The inner dielectric tube, which acted as the discharging electrode, was filled with an aqueous electrolyte solution. The outer dielectric tube, which served as the other electrode, was in contact with the wastewater, which was grounded. The present reactor system was energy-efficient for the production of ozone, not only because the perfect contact between the aqueous electrode and the dielectric surface minimized the loss of the electrical energy, but also because the DBD reactor was cooled by the wastewater. In addition, the ultraviolet （UV） light produced in the DBD reactor was able to assist in the wastewater treatment since the quartz tube used as the dielectric material was UV-transparent. The performance of the present DBD system was evaluated using a synthetic wastewater formed from distilled water and an azo dye, amaranth. The experimental parameters were the concentration of the electrolyte in the aqueous electrode, the discharge power, the initial pH of the wastewater and the concentration of hydrogen peroxide added to the wastewater. The wastewater treatment system was found to be effective for achieving decomposition of the dye.     

分光光度法测定水泥中的SO3

介绍了分光光度法测定水泥中SO3的方法。实验证明：离子强度对测定有很大影响,提出在工作曲线配入相应基体以消除影响的办法。研究了Fe^2＋、S^2-等还原性元素对测定的干扰及消除这种干扰的方法。确定了最佳的酸度、温度和反应时间等测定条件。该方法不仅测定时间短,操作简便,而且所用试剂以及仪器均为常用的,价格低廉,便于中小型水泥企业使用。     

灵芝中总黄酮的含量测定

为了测定灵芝中总黄酮的含量,利用黄酮类化合物与金属离子形成的螯合物在510nm处有最大吸收度,用分光光度法进行测定,测得总黄酮含量为0.385%.效果满意,方法简便可靠.     

栽培与野生重楼药材中重楼皂苷与无机元素含量的比较分析

目的：对野生和人工栽培重楼中的Ca、Mg、Fe、Mn、Zn、Cu六种无机元素及重楼中的主要药效成分重楼皂苷I的含量进行比较。方法：用混酸（浓硝酸和高氯酸按照体积比1：1混合而成）对10批样品进行浸泡、消煮,制备成供试品溶液。采用空气—乙炔火焰原子吸收光谱法测定无机元素;用超声提取,HPLC法测定重楼皂苷的含量。结果：野生重楼中无机元素的含量普遍比人工栽培重楼中元素元素含量要高,但是重楼皂苷I的含量栽培重楼普遍高于野生重楼。结论：本实验结果为重楼资源开发以重楼的药效性和药理毒理性提供了理论依据。     

分光光度法测定海参中锗的含量

对不同产地海参中总锗的含量进行测定.采用灰化法对样品进行处理,以CTMAB为增溶剂,明胶为稳定剂,苯芴酮为显色剂,在酸性条件下进行显色,利用分光光度法测定海参中锗的含量.该体系在503 nm处有最大吸收峰,回归方程为A=1.092 5 C+0.168 15,线性范围为0.072~0.504μg/mL,r=0.997 8,方法的回收率为98.54%~99.30%,RSD为1.9%.本方法样品处理简单,准确度高,可用于海参中锗的含量测定.     

阳离子表面活性剂平衡移动增敏机理的研究

本文研究了氯化十六烷基吡啶(CPC)对铜(Ⅱ)—邻硝基苯基萤光酮(ONPF)络合物在可见分光光度法中的增敏作用的机理。这种增敏效应被认为是由于CPC和Cu(Ⅱ)—ONPF络合物间的半分子缔合作用而引起的,阐明了增敏作用与溶液中CPC各存在型态间的关系及溶液体系的盐效应。     

三次样条插值卡尔曼滤波分光光度法同时测定NO_3~-和NO_2~-的研究

本文提出三次样条插值卡尔曼滤波分光光度法用于多组分同时测定，本法能减少实验工作量。对合成样中的ＮＯ－３和ＮＯ－２测定结果表明，此方法对不具自动扫描功能的分光光度计是有效的，且结果令人满意     

负吸光度法─—一种新的光度分析方法

本文在原有吸收光度法基础上提出了一种新的光度分析方法─—负吸光度法；归纳提出了用一般分析光度计进行负吸光度法测定的方法；为适应负吸光度法，对吸收光度法的定量原理─—朗伯—比尔定律进行了补充。