用模拟蚀孔内溶液的方法研究不锈钢蚀孔内溶液的化学性质

本文作者按18～8不锈钢成分用FeCl_2·4H_2O,CrCl_3·6H_2O和NiCl_2·6H_2O配制了不同浓度的模拟孔内溶液,测定了不同浓度和两个温度条件下模拟孔内溶液的水解速率,稳定pH值和电导率。结果表明,孔内溶液的水解速率很快,不同浓度溶液的水解速率几乎相同;孔内溶液的pH下降主要由CrCl_3水解所引起;温度对溶液的水解有很大影响;pH随溶液浓度增大而减小,电导率随浓度的变化则较复杂;孔内溶液的电导率很大,电偶电流通过孔内溶液不会产生显著的欧姆压降。     

含电气石热释电功能瓷膜对水pH值的影响

本文比较系统地研究了含电气石热释电功能瓷膜的制备;探讨了含电气石功能瓷膜与水作用过程中水的pH值变化规律及其作用机理.实验结果表明:电气石的粒径越小、容器中水越少,其对水体pH值影响越明显;随着初始水温度的升高效果有更明显的趋势;含电气石功能瓷膜烧结在750℃下保温2 h为最佳热处理方式,还原气氛中热处理比在大气气氛条件下对水pH值影响明显.     

溶液pH对电沉积氧化亚铜薄膜的影响

采用醋酸铜-醋酸钠酸性溶液和硫酸铜-乳酸碱性溶液,分析了不同pH下电沉积Cu2O薄膜的形貌及结构,讨论了镀液体系及溶液pH对Cu2O薄膜生长的影响,测定了不同形貌的Cu2O薄膜的光学透射性能.结果表明,溶液的氢氧根、羧基、羟基中的氧原子会影响Cu2O薄膜的结构及形貌.酸性溶液中,Cu2O薄膜易形成混晶结构;而碱性溶液中,随着pH的变化,Cu2O薄膜有不同的择优取向.酸性溶液中Cu2O薄膜形成网状结构,碱性溶液中易形成锥形结构.     

不同介质溶液对维生素C稳定性的影响研究

利用紫外分光光度法研究了无机盐、羧甲基纤维素钠、β-环糊精和聚乙二醇等介质溶液中维生素C的稳定性,并探索了上述介质溶液延缓维生素C被氧化的作用机理。结果表明,氯化镁、氯化钾、氯化钠、羧甲基纤维素钠均能较显著地提高维生素C的稳定性,而羧甲基纤维素钠对人体安全、使用量很少且效果显著,可广泛应用在化妆品、食品、医药等领域用以保护维生素C的稳定性。聚乙二醇、β-环糊精与维生素C的混合溶液中起始溶氧量与空白维生素C溶液相近且随时间延长下降很明显,而氯化钠、羧甲基纤维素钠和维生素C的混合溶液中起始溶氧量则远低于空白维生素C溶液并随时间延长下降很慢,这些现象与上述介质对维生素C的保护效果是一致的。介质溶液中起始溶氧量的高低及下降速度快慢影响了维生素C的稳定性,无机盐离子种类和浓度影响溶液中溶氧量,而羧甲基纤维素钠、聚乙二醇、β-环糊精等溶液的相对黏度则对溶氧量存在影响。     

湿法制备电池级四氧化三钴的研究

以氯化钴和碳酸钠为原料,采用湿法通过控制反应物的摩尔比、pH值、反应温度得到碳酸钴前驱体,前驱体经过二段烧结得到纯相的四氧化三钴微粉。用XRD、SEM等分析测试技术对氧化钴微粉进行表征。结果表明,四氧化三钴的粒径在2~11μm,平均粒径为8μm,粒径分布均匀,呈类球形颗粒,杂质元素含量低,满足了电池级四氧化三钴的要求。     

在生产氯碱中酸性盐水对隔膜电槽运转指标的影响

采用氯化钠酸性溶液代替隔膜电解的碱性溶液表明,能够在阳极液所有pH值范围内提高氯和碱的电流效率、改进其质量、提高氢氧化钠饱和浓度,当阳极液pH值与碱性溶液相同时,降低活性氯和氧的含量.试验证明,被推荐的氢氧化钠电流效率损耗机理,可以认为是供给酸性盐水对电解指标影响的特性.     

电气石对液态水团簇和沼泽红假单胞菌脱氢酶活性的影响

用化学个分析、X射线衍射分析、原子力显微镜等方法对内蒙古产黑色电气石进行测试表征。研究了电气石对液态水团簇和沼泽红假单胞菌脱氧酶活性的影响。结果显示：电气石使蒸馏水17^O核磁共振的半高幅宽变窄,降低了水分子缔合度。电气石提高了细胞脱氢酶活性,并使脱氧酶对pH值变化的稳定性增强。电气石对体系pH调控的结果表明：电气石使不同起始pH值溶液的pH值均趋向8．0左右。电气石提高脱氧酶活力除了电气石影响水的团簇外,还与其保持体系恒定的弱碱性pH有关。     

磁化条件下不同镁盐对碳酸钙溶解行为的影响

为阐明磁化条件下无机镁盐对碳酸钙溶解行为的影响规律,采用检测溶液电导率、pH和钙离子浓度等方法来考察磁化条件下不同种类镁盐（硫酸镁、硝酸镁、氯化镁和碳酸镁）对碳酸钙溶解行为的影响。结果表明,磁化条件下硫酸镁、硝酸镁和氯化镁对碳酸钙有促溶作用,作用最显著的是硫酸镁,其可使溶液钙离子浓度提高55.0%;碳酸镁对碳酸钙有阻溶作用,其可使溶液钙离子浓度减少36.0%。硫酸镁、硝酸镁和氯化镁对碳酸钙有促溶作用的原因在于溶液中镁离子产生的盐效应以及3种镁盐造成磁化碳酸钙溶液pH不同程度的减小。而碳酸镁对碳酸钙有阻溶作用的原因在于碳酸根产生的同离子效应和极化作用以及碳酸镁使磁化碳酸钙溶液pH增大。研究结果揭示了磁化溶液中不同镁盐对碳酸钙溶解行为的影响规律,可为利用镁盐调控碳酸钙溶解行为提供理论依据,并对强化磁化除垢效果有一定的参考意义。     

铅从釉与玻璃中被酸溶液溶出的机理

本文研究了在酸溶液腐蚀下铅从釉与玻璃中被溶出的过程,其中包括:酸溶液的pH值函数,化学反应的时间以及有关的温度。试验中所涉及的十一种不同饮料的酸度经计算也在本文作了交代。除此以外,为了解铅溶出过程中的动力学,特将几个化学组成不同,熔融时间也不同的玻璃试样作了研究。研究结果表明:如果酸溶液的pH值低的话,铅的溶出量将增加;酸腐蚀时间长,铅溶出量越高;化学反映的温度越高,被溶出的铅就越多。本文最后在有关玻璃游离体离子结合强度的学说的基础上,将碱性硅酸铅玻璃中铅离子的溶出机理作了解释。     

藤茶中抗氧化成分——二氢杨梅素在碱性溶液中的自氧化作用机理

为了进一步研究具有优异抗氧化能力的天然药物——二氢杨梅素,在碱性溶液中结构不稳定性原因及自氧化作用机制。实验分别采用了HPLC色谱法、~1HNMR、~(13)CNMR、ESI-MS及电子顺磁共振(EPR)技术,对二氢杨梅素在不同碱性环境中的行为变化进行研究。实验结果表明,二氢杨梅素分别在相同条件下,不同碱性的缓冲溶液(pH 7.4(PBS)、pH 8.5(Tris-HCl)、pH 9.4(Borax-NaOH))中,室温搅拌,均发现有杨梅素成分生成,并经~1HNMR、~(13)CNMR和ESI-MS技术进行结构确认。分别向等量的二氢杨梅素不同缓冲溶液(pH 7.4(PBS)、pH 8.5(Tris-HCl)、pH 9.4(Borax-NaOH))中,加入DMPO自由基捕获剂,经电子顺磁共振(EPR)技术,均能检测到DMPO-O~-_2·加合物的特征峰存在,且强度不同。相反,在氮气的条件下,其DMPO-O~-_2·加合物的特征峰强度大幅度降低。实验结果充分证明了二氢杨梅素在有氧且碱性溶液中,会导致自身分子结构不稳定,而产生超氧阴离子自由基的作用机制。     

SEDIMENTATION OF BINARY MIXTURES OF PARTICLES OF UNEQUAL DENSITIES AND OF DIFFERENT SIZES

A model is developed for the sedimentation from a suspension of two particle species of unequal densities and of different sizes. The composition and the thickness of various layers in the sediments are predicted using graphical and analytical methods. The model predictions were in excellent agreement with experimental results, when the particle size ratio was ≥ 108. When size ratio of the particles was 2.60 and 4.31 the agreement occurred in about 50 percent of the cases.     

COMPARISON OF METHODS OF ANALYSIS OF GYPSUM1

The different analytical methods proposed for the evaluation of gypsum have been subjected to an experimental test. A combination method, consisting of a fusion with KHCO₃ and determination of CaO by KMnO₄ titration, the SO₃ by Andrews method of titration of BaCrO₄ has been found to give very reliable results with the least consumption of time.     

氢气纯度分析方法准确性的探讨

ONACCURACYOFANALYSISOFOFHYDROGEN1前言我公司目前应用的氢气纯度分析方法有两种,一种是爆炸反应法,另一种是焦性没食子酸吸收法。几年来,人们对两种分析方法的准确性曾有过褒贬不一的评论。这里我们也谈谈自己粗浅的观点。2爆炸法测定氢气纯度一定量的氢气样品与适量的空气之均匀混合物因反应后生成液体水而引起气体体积减少,减少的体积等于参加反应气体体积之和。其中l／3为氧气,2／3为氢气。根据氢气取样量和反应前后混气体体积之差,以及氢气在反应中的体积比例关系,可计算出样品的氢气纯度。计算公式式中：A一混…     

骑式摩托车油箱喷涂工艺的改进

面对日益激烈的市场竞争,摩托车油箱外观质量越来越成为影响销售的因素之一。文章介绍了改进工艺后的油箱涂装,该涂装体系提高了油箱外观的丰满度,降低了油箱涂装的生产成本。     

HEASUREHENT OF INSTANTANEOUS RATES OF LOSS OF VOIATILE COMPOUNDS DURING DRYING OF DROPS

A novel technique serves to monitor instantaneous rates of loss of a volatile solute from a suspended drop during drying. A highly sensitive electron capture detector is used to monitor concentrations of SF6 released into a flowing gas stream from a suspended, drying drop. Simultaneously, the appearance and morphological development of the drop are monitored with a video camera. This provides the wherewithal of relating instantaneous rates of loss of the volatile solute to particular events during the development of particle morphology.

Initial experiments have been carried out with drops of aqueous solutions of glucose, sucrose, maltodextrin and coffee extract. The results clearly display the onset of the volatiles-retentive selective diffusion phenomenon. There is also substantial loss of the volatile component later in the drying process, when the drops undergo repeated ex ansion, bursting and cratering due to the formation of internaf bubbles. These experiments appear to be the first quantitative demonstration of major losses accompanying changes in drop morphology.     

用两个形状指数表征粉煤灰颗粒形貌的研究

引用两个形状指数表征颗粒形状的概念,即先将颗粒形状近似为椭圆,再将椭圆图像分离:以圆为基准的颗粒宏观形状指数δ;以光滑椭圆为基准的颗粒轮廓凹凸度,即微观形状指数ζ。分析和发展了近似椭圆模型。并运用图像分析仪对粉煤灰、水泥样品进行实验。结果表明,粉煤灰颗粒的两个形状指数δ和ζ都大于水泥颗粒。证明粉煤灰颗粒的球形度、表面光滑度优于水泥,而且,随着粒径增大,δ和ζ呈下降趋势,表明磨制颗粒越粗。(?)粒形状越不规则。文中还运用近似椭圆模型再现了颗粒的模拟图像。     

典型煤碳燃烧特性研究和数值模拟

本文以三种典型煤的碳燃烧为研究对象，分别采用简单一维沉降燃烧方式和等温加热燃烧方式，实验研究了煤在快速加热条件下，其碳的初期和中，后期燃烧过程。以实验为基础，建立了煤的碳燃烧模型，变工况数值模拟了煤的碳燃烧过程，揭示了煤不同条件下的单颗粒碳燃烧特性。     

茶多酚提取方法进展

本文综述了国内外现有茶多酚提取方法的现状以及近期的研究进展，并对其优缺点进行了评价。这将有助于中低档茶的综合利用和茶多酚的进一步开发应用。     

卫生陶瓷烧成用窑炉发展之我见

归纳了当今卫生陶瓷工业的发展现状和水平 ,对窑炉产业提出了的新要求 ,分析了某一新型窑炉的特点 ,对发展我国陶瓷窑炉产业提出了建议     

ANALYSIS OF RECENT MEASUREMENTS OF THE VISCOSITY OF GLASSES

Viscosity of Simple Soda-Silicate 500° to 1400°C Comparison of the results given by English with those of Washburn, Shelton and Libman, indicates a discrepancy in the absolute values of log₁₀ viscosity amounting to 0.6, those of Washburn et al., being relatively too high. If correction for this is made, the isothermal curves of log₁₀ viscosity as a function of soda content are smooth up to 50% Na₂O, showing no inflection. The observations as a function of temperature T are all represented within accidental error by an equation of the type where all three constants vary regularly with the composition. Change of Viscosity of Glass (6SiO₂, 2Na₂O) due to Molecular Substitution of CaO, MgO and Al₂O₃ for Na₂O The effect is clearly brought out by plotting (from the results of English) the change of log₁₀η due to the substitution as a function of temperature. The curves each show a sharp bend at a temperature between 840° and 1050°C, which is designated the aggregation temperature T_a. If we divide these curves by the corresponding percentage substituted, we get curves for each oxide which are straight and parallel below the aggregation temperatures, the slopes (increase of change of log₁₀η per 100°C) being −0.056 (CaO), −0.055 (MgO), −0.018 (A1₂O₃) per per cent oxide substituted. For substitution of 1/2 molecule the slopes are −0.325 (CaO), −0.23 (MgO) and −0.18 (Al₂O₃) per 100°. At the aggregation temperature the change of log₁₀η per per cent is a minimum, 0.03 to 0.06 for CaO, 0.12 for MgO, 0.07 for Al₂O₃. Evidence of Aggregation in Glasses, from viscosity Measurements The sharp bends in the plots of change of log₁₀η due to substitution of an oxide for Na₂O, suggest the beginning of molecular aggregation at these temperatures. These aggregation temperatures are close to the devitrification temperatures, but the effect on the viscosity curves cannot be due to actual devitrification since it does not change with time. Taking the aggregation temperatures as equal to devitrification temperatures, additional isotherms are roughly sketched into the equilibrium triangle of the system Na₂O-CaO-SiO₂. Change of Viscosity of Glass (4SiO₂, 2Na₂O) due to of Substitution of B₂O₃ for SiO₂ The change of log₁₀η (from the results of English) is plotted as a function of temperature, and also the change of log₁₀η per per cent B₂O₃. The curves are more complex than for the substitution for Na₂O.