弱酸弱碱多元非线性回归电位返滴定

在被测弱酸或弱碱溶液中加入一定量过量ＮａＯＨ或ＨＣｌ标准溶液，再返滴入ＨＣｌ或ＮａＯＨ标准溶液若干次，依次测定ＰＨ玻璃电极在被测溶液中的电极电位。本方法的突优点是不需要活度与浓度的换算，不需要另行测定工作曲线。测定了ＮａＡｃ和（ＮＨ３）２ＳＯ４等弱酸弱碱，结果令人满意。     

Triton X—100／C10H21OH／H2O体系层状液晶中水溶性超微粒子材…

利用溶剂在层状液晶中的渗透性和层状液晶中溶剂层厚度的限定性，在ＴｒｉｔｏｎＸ－１００／Ｃ１０Ｈ２１ＯＨ／Ｈ２Ｏ体系状液晶中，以饱和Ｎａ２Ｃ２Ｏ４水溶液代替给分水制备水溶性超微粒子材料Ｎａ２Ｃ２Ｏ４，平均粒径约为６ｎｍ。     

钠化合物洗提钨及混合洗提中共存反离子的加速效应

研究了在季胺Ⅰ型强碱性阴离子交换树脂上用ＮａＯＨ、ＮａＮＯ３、ＮａＣｌ和ＮＨ４Ｃｌ洗提及洗提后的吸附特性。给出了洗提曲线、穿透曲线和工作交换容量。采用ＮａＣｌ和ＮａＯＨ混合洗提的工艺，获得了钨浓度高而过剩洗提剂含量低的洗出液。为由洗出液蒸发结晶制取高纯Ｎａ２ＷＯ４·２Ｈ２Ｏ开辟了途径。混合洗提的宏观结果表明：由于反离子的存在，Ｃｌ－、ＯＨ－和在溶液相或交换剂中的扩散系数发生改变，→Ｃｌ－及→ＯＨ－的交换速度加快了。     

弱酸弱碱非线性回归电位返滴定的研究

本文提出的方法是在被测弱酸或弱碱溶液中加入一定量过量ＮａＯＨ或ＨＣｌ材料溶液，再返滴入ＨＣｌ或ＨａＯＨ材料溶液若干次，依次用电位法测定被测溶液中质子浓度，根据有关酸碱平衡和物料平衡原理及非线性回归原理对实验数据进行处理。     

Triton X－100／C_（10）H_（21）OH／H_2O体系层状液晶中水溶性超微粒子材料Na_2C_2O_4的制备

利用溶剂在层状液晶中的渗透性和层状液晶中溶剂层厚度的限定性，在ＴｒｉｔｏｎＸ－１００／Ｃ_（１０）Ｈ_（２１）ＯＨ／Ｈ_２Ｏ体系层状液晶中，以饱和Ｎａ_２Ｃ_２Ｏ_４水溶液代替组分水制备水溶性超微粒子材料Ｎａ_２Ｃ_２Ｏ_４，平均粒径约为６ｎｍ．     

荧光分光光度法测定海藻中的石油烃

用索氏提取法，ＮａＯＨ－消解法和超声振荡萃取法提取海藻样品中的石油烃成分，荧光分光光度计测定石油烃含量，结果表明，ＮａＯＨ－消解能够更有效从样品中提取石油烃，其检测限为０．０７５ｍｇ／ｋｇ。     

化学法同时测定含氮有机化合物的碳和氮

建立了一个新的化学分析方法，即含氮有机化合物与催化剂、氧化剂相混和，在氧气流下于空气浴上加热分解，Ｃ转变成ＣＯ２，用稀ＮａＯＨ溶液吸收，以标准ＨＣｌ溶液滴定；Ｎ转变成ＮＨ３，以克达尔定氮法测定，测定误差都小于±０．５％。     

氯碳酸镁盐的溶解、转化机制及动力学研究

采用ＮＨ４ＨＣＯ３溶液逐滴加入浓的ＭｇＣｌ２水溶液中，经回流沸腾制得氯碳酸镁盐的晶体２ＭｇＣＯ３．Ｍｇ（ＯＨ）２．ＭｇＣｌ２．６Ｈ２Ｏ。     

硼掺杂多晶金刚石薄膜电极的电化学特性

用循环伏安法和恒电位法研究了硼掺杂多晶金刚石薄膜电极（ＤＦＥ）的若干电化学特性。电极面积４×４ｍｍ＾２。在０．１ｍｏｌ／Ｌ ＫＣｌ，ＮａＮＯ３，ＮａＯＨ和ＫＨ２ＰＯ４＋Ｎａ２ＨＰＯ４（ｐＨ＝６．８６）电解质溶液中电势窗口均为－５００￣＋８００ｍＶ；而在０．１ｍｏｌ／Ｌ ＨＣｌ和Ｈ２ＳＯ４溶液中电势窗口为－２００￣＋１１００ｍＶ．Ｋ３Ｆｅ（ＣＮ）６的氧化峰电位为＋５００ｍＶ，与Ｐｔ电极测量相同；校正     

电导法快速测定黑生料及煤中碳含量

本文利用碱熔液吸收ＣＯ２后电导率的变化值与吸收的ＣＯ２含量成正比这一关系来测定生料中的含碳量。５％ＫＯＨ溶液为最佳的吸收溶液。选择了最佳实验条件，在浓Ｈ２ＳＯ４介质中，煤或黑生料与氧化剂共热产生的ＣＯ２由ＫＯＨ溶液吸收。通过测定ＫＯＨ溶液吸收ＣＯ２前后电导率的变化值来确定含碳量。对标准煤样及黑生料进行了测定，得到了较为满意的结果。     

溶胶-凝胶法制备纳米氢氧化铝溶胶

研究了利用铝酸钠溶液碳酸化产生的沉淀, 经胶溶作用制备出纳米氢氧化铝溶胶的过程. 分析了铝酸钠溶液滴加到大量碳酸氢钠溶液中时发生的反应. X射线衍射研究结果表明, 在纳米氢氧化铝溶胶制备过程中, 从无定形氢氧化铝沉淀到拟薄水铝石的晶型转变过程是氢氧化铝沉淀胶溶时溶解再析出的过程. 将碳酸氢钠加入到苛性比为1.7的铝酸钠溶液中, 中和至苛性比为1.3后, 溶液诱导期中的紫外光谱显示270 nm处的Al(OH)3-6吸收增强. 经与含铝原子六配位的晶体紫外光谱对比后表明, 在铝酸钠分解生成氢氧化铝的过程中, 其铝的配位结构从四配位转化为六配位. 拟薄水铝石溶胶粒子的形貌与胶溶所用的酸和分散剂有关.     

Chitosan Obtained from Cell Wall of Aspergillus Niger Mycelium

Chitin from cell walls of Aspergillus Niger mycelium was prepared. A new method for the preparation of high deacetylation degree chitosan was studied in a dilute sodium hydroxide solution at a high pressure. The experimental results indicate that the deacetylation degree of the chitosan can reach 80% under the condition of a 5.00 mol/L sodium hydroxide solution at 0. 1 MPa of pressure for 1 h. This method shows the advantages of the applications in the industry production and environment protection.     

A Facile Synthesis of Thioacids by Hydrolysis of 1-(Acylthio)ethaniminium Chlorides

A facile method for the preparation of thioacids in moderate to good yields has been developed by hydrolysis of 1-(acylthio)ethaniminium chlorides under a liquid-liquid two phase system consisting of benzene and a sodium hydroxide aqueous solution at room temperature. We have achieved facile preparation of these compounds without use of toxic compounds such as hydrogen sulfide.     

Synthesis of hydroxy derivatives of 2,5-diaryl-1,3,4-oxadiazoles

A method for the synthesis of hydroxy derivatives of 2, 5-diaryl-1,3,4-oxadiazoles has been developed which consists in the preparation of acetoxy derivatives of oxadiazole with their subsequent saponification by means of an alcoholic solution of sodium hydroxide.     

Chemical modification of cellulose extracted from sugarcane bagasse: Preparation of hydroxyethyl cellulose

Cellulose was extracted from sugarcane bagasse by alkaline extraction with sodium hydroxide followed by delignification/bleaching using sodium chlorite/hexamethylenetetramine system. Factors affecting extraction process, including sodium hydroxide concentration, hexamethylenetetramine concentration and temperature were studied and optimum conditions for alkaline extraction were found to be boiling finely ground bagasse under reflux in 1 N sodium hydroxide solution and then carrying out the delignification/bleaching treatment at 95 °C using 5 g/l sodium chlorite together with 0.02 g/l hexamethylenetetramine. The extracted cellulose was used in the preparation of hydroxyethyl cellulose through reaction with ethylene oxide in alkaline medium. Factors affecting the hydroxyethylation reaction, like sodium hydroxide concentration during the alkali formation step, ethylene oxide concentration, reaction temperature and reaction duration were studied. Optimum conditions for hydroxyethylation reaction were using 20% NaOH solution and 200% ethylene oxide (based on weight of cellulose), carrying out the reaction at 100 °C for 60 min.     

Hypervalent Iodine in Synthesis

A new and facile method for the preparation of arenetellurinic mixed anhydrides is described from diaryl ditellurides and phenyliodine (III) dicarboxylates. Hydrolysis of the arenetellurinic mixed anhydrides gives arenetellurinic anhydrides and a one - pot procedure involving the reaction of diaryl ditellurides with phenyliodine (III) dicarboxylates in a two - phase system of methylene chloride and aqueous solution of sodium hydroxide for the preparation of arenetellurinic anhydrides is provided.     

pH-Metric determination of D-Sorbitol in the medicinal preparation poliamin

A procedure for the potentiometric determination of D-sorbitol in the solution of a medicinal preparation Poliamin was developed. The procedure involved binding of sorbitol with boric acid to form borosorbic acid, which was subsequently titrated with a standard solution of sodium hydroxide to a constant pH. The effect of pH and the concentrations of reagents on the accuracy of the results of analysis was studied     

Determination of cesium-137 in water by ion exchange

The preparation of ammonium molybdophosphate (AMP) precipitated directly into the IRA-900 resinous structure and their application to the determination of cesium-137 in waters are described. The sample of water is passed through the resin, which retains the cesium. After the removal of strontium-90 and potassium-40 with 0.1M ammonium nitrate solution, the cesium is eluted with 1M sodium hydroxide solution. The AMP dissolved in the alkaline solution is used to precipitate the cesium by acidifying the solution.     

Fibre-optic fluorescing sensor for ammonia

The fluorescing sensor is based on the change in fluorescence intensity of a buffered pH indicator solution entrapped in silicone rubber. Exposure to ammonia increases the pH of the trapped solution; this increases the fluorescence intensity, which is monitored via an optical fibre bundle. Ammonium chloride in 0.001 M sodium hydroxide, or the indicators themselves, can serve as buffers. Effects of sensor preparation and buffer composition on response time, reversibility and sensitivity are discussed.     

The determination of nitrate and chloride in sodium hydroxide solutions by means of cation exchangers,in the manufacturing control of alkaline batteries

The most important types of alkaline batteries are described. A method for the determination of chloride and nitrate ions in sodium hydroxide solutions has been developed The analysis is performed in the following manner: the solution is passed through a layer of a cation exchanger in the hydrogenform,wherebythe sodium hydroxide is neutralized. The liberated hydrochloric and nitric acids respectively are determined through titration. This method has been used for the manufacturing control of nickel-cadmium batteries.