离子膜电解液中氢氧化钠含量的测定

介绍了离子膜电解液中氢氧化纳含量测定的另一种方法———质量浓度温度校正系数法,此方法可以直接得到生产温度下电解液的质量浓度(g/L),从而更准确、有效地指导生产。

稀土原料中铈的分离及纯氧化铈的制备

稀土原料用硫酸复盐凈化,试验得Na_2So_4:RE_2O_3以7:1(克分子比)为适宜用量。复盐碱化水解成稀土氢氧化物后,试验得出将三价的氢氧化铈氧化成四价的氢氧化铈最良好的条件为:在用浓度为12％的NaoH溶液(过量10％)来碱化复盐时,如果在加热的情况下碱化水解,并趁热抽滤,卽有大部分三价铈氧化,氧化程度可达93％左右。随后只要在110℃烘干2-4小时氧化卽将继续进行到底。同时,尚试验得如果按一般经典手续来氧化时,由于某些不明原因氧化受阻碍时进行处理的方法。从原料溶解直至最后用浓硝酸法提纯氢氧化铈,一次提纯可得纯度为96％灼烧的CeO_2,两次提纯可得纯度近99％的灼烧CeO_2。至于铈的回收率,从原料溶解至氢氧化物氧化为止为93％,如果至第一次浓硝酸提纯止则总回收率为63％。如果母液循环用则总回收率将更高。本试验另得结果关于氯根对三价铈氧化成四价铈过程没有起不良影响。这就使原料的溶解可以采用盐酸,而碱化水解硫酸复盐时也有可能采用电解液碱。验证过分析铈的一些容量方法。

多元统计方法在产品质量控制中的应用

工业用氢氧化钠的主要成份是氢氧化钠、碳酸钠、氯化钠 ,这三个原素的含量多少决定产品质量。本文用三个随机变量代表这三种成份含量 ,并假设这三个变量的联合概率分布是多元正态的 ,在此基础上采用多元统计分析中的τ2统计量和多元控制方法相结合 。

Preparation of gradient wettability surface by anodization depositing copper hydroxide on copper surface

A facile route for preparation of gradient wettability surface on copper substrate with contact angle changing from 90.3°to4.2°was developed.The Cu（OH）2 nanoribbon arrays were electrochemically deposited on copper foil via a modified anodization technology,and the growth degree and density of the Cu（OH）2 arrays may be controlled varying with position along the substrate by slowly adding aqueous solution of KOH into the two-electrode cell of an anodization system to form the gradient surface.The prepared surface was water resistant and thermal stable,which could keep its gradient wetting property after being immersed in water bath at 100℃ for 10 h.The results of scanning electron microscopy（SEM）,X-ray diffraction（XRD） and X-ray photoelectron spectroscopy（XPS） demonstrate that the distribution of Cu（OH）2 nanoribbon arrays on copper surface are responsible for the gradient wettability.

Preparation and electrochemical performance of nano-scale Ni(OH)_2 doped with zinc

Nano-scale Ni（OH）2 doped with Zn was prepared by precipitation transformation method and characterized by XRD and TEM. The electrochemical performance was investigated by cyclic voltammetry （CV） and constant current technology. The measurement results indicate that the lattice parameters of nano-scale Ni（OH）2 are changed and the agglomeration of particles becomes obvious with the increased Zn-doped content. Compared with un-doped one, the discharge specific capacities ofnano-scale Ni（OH）2 doped with 10% Zn are enhanced by 8% and 6%, respectively, at the discharge rate of 0.2C and 3C. After 110 cycles, the discharge specific capacity of the sample doped with 10% zinc is still above 85% of its initial capacity discharged at 0.2C. Therefore, a suitable Zn-doped content is beneficial to improving the discharge performance of nano-scale Ni（OH）2.

Preparation, Structures Nano TiO_2 Particles, and the properties of TiH_2 Coated with Nano TiO_2

The surface of Titanium Hydride (TiH 2) is coated by Nano Titanium Dioxide (TiO 2) particles prepared in both of methods of hydrolysis reaction of Ti(OC 4H 9) 4 and base precipitation reaction of Ti(SO 4) 2. TiH 2 coated with nano TiO 2 particles, in which there is an oxidation film on its surface, shown in the experiments, will obviously achieve good effects on releasing hydrogen slowly in high temperature. There are different structures and properties of TiH 2 coated by nano TiO 2 particles prepared in different ways in high temperature, which can influence on releasing hydrogen.

化学概念和原理的记忆方法初探

现行中学化学教材中,有很多难于理解、记忆的原理和概念,教师若不想办法让学生理解、记住这些原理和概念,则学生就可能难于理解,记不住,更不用说运用了。基于这种情况,笔者采取如下几种方法来帮助学生理解和记忆。 1 归纳法 通过归纳,可将繁琐的过程变得较为简单,既便于理解,也便于记忆, 如摩尔浓度与百分比浓度的换算这一计算问题,根据摩尔浓度的定义,1升溶液里含溶质多少摩尔,则其摩尔浓度就是多少。因此将百分比浓度换算成摩尔浓度时,若按题目所给的条件来逐一计算,则步骤较多,显得麻烦,甚至有些学生无从下手,因而我在讲解这类例题前,先引导学生进一步复习摩尔浓度的含义,在分析定义的基础上归纳出将百分比浓度换算成摩尔浓度的一个简单式子。即 (1000×ρ×A％)/溶质的摩尔质量(式小ρ为溶液的密度,单位为克/厘米~3A％为溶液的百分比浓度)。 由上式计算所得的结果,其数值就是溶液的摩尔浓度的数值,最后在数值后加工摩尔浓度的单位即可。 例 把88克氢氧化纳溶于100克水中,溶液的密度是1.09克/厘米~3。

《初三化学》新教材课堂教学形式初探

上海的中学课程改革,既是为了适应当前社会发展的需要,也是为培养21世纪人才的需要。新编初三化学教材(长宁版)是属于学科体系,但兼收并蓄社会课题型及学生发展型教材的长处,使学生既接触一些化学基础知识。

Effects of reaction parameters on preparation of Cu nanoparticles via aqueous solution reduction method with NaBH_4

The preparation of Cu nanoparticles by the aqueous solution reduction method was investigated. The effects of different reaction parameters on the preparation of Cu nanoparticles were studied. The optimum conditions for preparing well-dispersed nanoparticles were found as follows: 0.4 mol/L NaBH4 was added into solution containing 0.2 mol/L Cu2+, 1.0% gelatin dispersant in mass fraction, and 1.2 mol/L NH3?H2O at pH 12 and 313 K. In addition, a series of experiments were performed to discover the reaction process. NH3?H2O was found to be able to modulate the reaction process. At pH=10, Cu2+ was transformed to Cu(NH3)42+ as precursor after the addition of NH3?H2O, and then Cu(NH3)42+ was reduced by NaBH4 solution. At pH=12, Cu2+ was transformed to Cu(OH)2 as precursor after the addition of NH3?H2O, and Cu(OH)2 was then reduced by NaBH4 solution.

受潮饲草的处理

受潮饲草的处理稻草、麦秸和其它饲草，遇高温与潮湿就会霉变，滋生和繁殖病原微生物，家畜采食后易发生胃炎、细菌性肠炎等消化道疾病，甚至中毒和死亡。为保障畜禽健康生长，除严禁用霉败饲草喂家畜外，一般受潮饲草必须经过无害化处理后方可饲用。常用方法如下：一、日...

苹果脆片

苹果脆片是在真空状态下,通过油炸的方法、将苹果内的水分蒸发掉,从而得到含水在5%左右的制品。它不含色素,无防腐剂,富含纤维,是纯天然的休闲食品。苹查脆片的加工要点是: (1)原料清洗用1%氢氧化纳和0.1-0.2%的洗涤剂混合液,40℃温水浸泡10分钟,然后捞出水洗,充分洗去果实表面的洗涤剂。(2)切片切除病虫和腐烂部分,去花萼、果柄。

4—色满酮及其衍生物的性质和反应

4 一色满酮是一类很重要的化合物,它的很多衍生物具有重要的药理作用。[1—4]前文报道了它和它的衍生物的合成[5—6]。本文就其性质和反应作一评述。1.显色反应4 一色满酮及其衍生物在氢氧化纳,硫酸,氯化镁的盐酸溶液及纳汞齐的Then acid溶液中显示不同的颜色。以2.2一二甲基—4—色满酮的一些衍生物为例[7]列表如下:

我省离子膜烧碱应优化发展

最近我省氯碱及井矿盐业拟新建、扩建一批离子膜烧碱生产装置,正在进行2～5万吨乃至10万吨规模烧碱项目的中外合资或引进准备工作。据了解,全省共有15个企业拟增加的离子膜烧碱生产能力达40～50万吨,超过全省现有烧碱生产能力。

临界水分解PCB新技术

日本工业技术院物质工学工业技术研究所成功完成利用临界水将PCB几乎完全分解的实验。新方法的特点是在分解反应中加入氢氧纳来处理混入PCB的绝缘油，没有副反应，不会产生有害物质。

Preparation and characterization of MWCNTs/LDHs nanohybrids for removal of Congo red from aqueous solution

The assembly of layered double hydroxides （LDHs） and multi-walled carbon nanotubes （MWCNTs） nanohybrids was prepared as MWCNTs/LDHs by co-precipitation. The synthesized nanoparticles were characterized by using XRD, FT-IR, SEM/EDX, TGA and BET. XRD and SEM studies proved that MWCNTs phases did not enter into the interlayers of LDHs, they dispersed over the LDHs surface homogeneously. BET results showed that MWCNTs/LDHs possessed hierarchically porous nanostructure with large surface area （124.974 m^2/g） and great pore volume （0.604 cm^3/g）. Batch experiments were conducted to study the adsorption efficiency of Congo red （CR）. It was worthy to note that MWCNTs/LDHs exhibited excellent adsorption performance with the maximum CR adsorption capacity of 595.8 mg/g in weak acidic environment. The adsorption kinetics and isotherm parameters can be well described by the pseudo-second-order and the Langmuir isotherm models, respectively. The thermodynamic studies indicated that the adsorption process was spontaneous and endothermic.

Effect of calcination temperatures on photocatalytic H_(2)O_(2)-production activity of ZnO nanorods

Photocatalytic hydrogen peroxide(H_(2)O_(2))production from O_(2) and H2O is an ideal process for solar‐to‐chemical energy conversion.Herein,ZnO nanorods are prepared via a simple hydrothermal method for photocatalytic H_(2)O_(2) production.The ZnO nanorods exhibit varied performance with different calcination temperatures.Benefiting from calcination,the separation efficiency of photo‐induced carriers is significantly improved,leading to the superior photocatalytic activity for H_(2)O_(2) production.The H_(2)O_(2) produced by ZnO calcined at 300℃ is 285μmol L^(−1),which is over 5 times larger than that produced by untreated ZnO.This work provides an insight into photocatalytic H2O2 production mechanism by ZnO nanorods,and presents a promising strategy to H2O2 production.

Enhanced electrocatalytic activity for H_2O_2 production by the oxygen reduction reaction: Rational control of the structure and composition of multi-walled carbon nanotubes

Hydrogen peroxide(H2O2)is a very useful chemical reagent,but the current industrial methods for its production suffer from serious energy consumption problems.Using high-activity and high-selectivity catalysts to electrocatalyze the oxygen reduction reaction(ORR)through a two-electron(2e^-)pathway is a very promising route to produce H2O2.In this work,we obtained partially oxidized multi-walled carbon nanotubes(MWCNTs)with controlled structure and composition by oxidation with concentrated sulfate and potassium permanganate at 40℃ for 1 h(O-CNTs-40-1).The outer layers of O-CNTs-40-1 are damaged with defects and oxygen-containing functional groups,while the inner layers are maintained intact.The optimized structure and composition of the partially oxidized MWCNTs ensure that O-CNTs-40-1 possesses both a sufficient number of catalytic sites and good conductivity.The results of rotating ring disk electrode measurements reveal that,among all oxidized MWCNTs,O-CNTs-40-1 shows the greatest improvement in hydrogen peroxide selectivity(from ~ 30% to ~ 50%)and electron transfer number(from ~ 3.4 to ~ 3.0)compared to those of the raw MWCNTs.The results of electrochemical impedance spectroscopy measurements indicate that both the charge-transfer and intrinsic resistances of O-CNTs-40-1 are lower than those of the raw MWCNTs and of the other oxidized MWCNTs.Finally,direct tests of the H2O2 production confirm the greatly improved catalytic activity of O-CNTs-40-1 relative to that of the raw MWCNTs.

Protective Actions of Blumea Flavanones on Primary Cultured Hepatocytes and Liver Subcellular Organelle against Lipid Peroxidation

To search for the protective actions of blumea flavanones (BFs) on hepatocytes and hepatic subcellular organelle against lipid peroxidation, monkey′s hepatocytes were isolated and cultured with or without blumea flavanones, then damaged by FeSO 4 cysteine or CCl 4. The lipid peroxidation (malondialdehyde production) and alteration in hepatocyte membrane (leakage of GPT) were estimated. Hepatic subcellular organelles were also isolated and incubated with or without blumea flavanones, then injured by FeSO 4 ascorbate. The generation of malondialdehyde(MDA) was measured. It was found that BFs 10 and 100 μmol·L 1 inhibited the MDA generation and GPT (glutamic pyruvic transaminase) leakage out of hepatocytes that were induced by CCl 4 or FeSO 4 cysteine. BFs could prevent lipid peroxidation initiated by FeSO 4 ascorbate in subcellular organelle suspension. Among BFs, BF 2 possessed the strongest activity. Conclusion: Blumea flavanones possess antioxidation activities that protect monkey′s hepatocytes and hepatic subcellular organelle against injuries induced by FeSO4 or CCl 4.

The Influence of Transmutation Conditions on the Adulteration Performance of Nano-scale Nickel Hydroxide

Spherical Nano-scale nickel hydroxide was prepared through precipitation transmutation method by controlling the transmutation conditions in this paper. The measurement results of XRD and TEM indicate that the crystallization of the nano-scale nickel hydroxide isβ-style and its shape is spherical with a diameter of 40～70 nanometer. The adulteration experiment shows that the adulteration ratio of nano- scale Ni(OH) 2 in common spherical micrometer-scale Ni(OH) 2 exists a optimal value (1∶9). And at this point, the utilization ratio of Ni(OH) 2 in electrodes can be raised by 10%, and the nano-scale nickel hydroxide with sphericity shape shows a better adulteration performance than that with needle shape.