乙酸苄酯的合成

以氯化苄和无水乙酸钠为原料,三乙基苄基氯化铵(TEBAC)为催化剂合成乙酸苄酯。考察了水的加量、反应温度、原料配比、催化剂用量、反应时间等因素对反应收率的影响。结果表明:当n(氯化苄):n(无水乙酸钠):n(TEBAC):n(水)=1:1.25:0.02:0.45,反应温度110℃,反应时间4h,产物摩尔收率可达94.50%。     

铜及铜合金线材酸洗液配方的改进

提出了一种新的酸洗配方,并通过实验考查了酸洗液各组分浓度对铜及铜合金线材酸洗效果的影响。研究结果表明：当硫酸浓度为350~400mL/L、硝酸钠浓度为50~80g/L、光亮剂浓度为1~5g/L时,该酸洗液能够较为彻底地去除氧化层,使铜线表面光亮。新酸洗液配方不仅降低铜损,而且减少＂黄烟＂,改善了作业环境。     

醇钠法合成一缩二丙二醇的工艺过程控制

介绍了一缩二丙二醇的用途及合成方法,重点阐述了以乙醇钠为催化剂,用丙二醇和环氧丙烷在一定温度和压力条件下合成一缩二丙二醇的反应原理和工艺流程,从反应温度、压力、精馏方式、催化剂回收等方面对生产工艺过程控制进行了探讨,总结出一种效率高,成本低,质量好的一缩二丙二醇的生产工艺条件。     

清净工序废次钠水回收工艺改进

针对电石法PVC生产中乙炔清净工序产生的废次钠水,经过试验制定改造回用方案,达到了节能减排的目的。     

Na2O-TiO2-SiO2-CaO-Al2O3-V2O5-MnO-MgO-FeO渣系渣铁间硫分配比热力学模型

基于离子分子共存理论(IMCT)建立了Na₂O-TiO₂-SiO₂-CaO-Al₂O₃-V₂O₅-MnO-MgO-FeO九元渣系的结构单元作用浓度模型和渣铁间硫分配比热力学模型,并对模型进行实验验证。通过模型计算出1200℃下渣系主要结构单元组成和渣中Na₂O,CaO,MnO,MgO和FeO的活度,发现Na₂O的加入可促进渣中低熔点物质的生成,降低渣系熔化性温度,改善脱硫反应的动力学条件;同时随着Na₂O加入量的增加,渣中Na₂O和CaO的活度增加,进而降低渣中S^2?离子活度,强化渣铁间脱硫反应。实验结果表明,增加碱矿比提高了渣铁间硫分配比,有利于铁水深度脱硫,铁水中硫含量可降至0.0005wt%以下,硫分配比的理论计算值与实验结果吻合极好。渣中各碱性氧化物的硫分配比随碱矿比R_N/C增加逐渐增大,各碱性氧...     

可见光下Cu2O/TiO2催化臭氧氧化头孢曲松钠性能研究

抗生素是治疗各种传染病的常用药物,但残留在水环境中的抗生素会对生态系统造成威胁。因此,探索去除水环境中抗生素的有效方法具有重要意义。由于光催化臭氧氧化技术可以高效降解和矿化水体中的污染物,该技术受到广泛关注。本工作通过浸渍-化学还原法制备Cu₂O/TiO₂复合材料并将其作为可见光催化臭氧氧化头孢曲松钠(CRO)的催化剂。利用X射线衍射仪(XRD)、傅里叶变换红外光谱仪(FT-IR)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、比表面积分析仪(BET)和紫外-可见漫反射光谱仪(UV-Vis DRS)对Cu₂O/TiO₂形貌结构和光学性能进行表征,考察了Cu₂O/TiO₂配比、Cu₂O/TiO₂投加量、臭氧浓度、头孢曲松钠初始浓度、溶液初始pH值等因素对可见光催化臭氧氧化头孢曲松钠的影响。结果表明,Cu₂O对TiO₂的掺杂改性使材料孔容和平均孔径增大,能带宽度减小,...     

脱墨化学品对Netbond助留系统影响的初步研究

对脱墨化学品，如表面活性剂、硅酸钠，螯合剂等对Netbond助留系统助留效果的影响进行了初步研究，结果表明它们对Netbond助留系统有着不同的影响和不利的影响。     

海藻纤维吸附性能的测试与研究

利用核磁共振（^1H—NMR）测定了不同海藻酸钠的M／G值，经湿法纺丝法制备了海藻纤维，并研究了M／G值、海藻酸钠用量及凝固浴用量和凝固时间对海藻纤维吸附性能的影响结果表明，海藻纤维对不同液体的吸附能力不同，其顺序为：生理盐水〉A溶液〉自来水〉蒸馏水；海藻纤维对生理盐水和A溶液的吸附能力随着M／G值的增加而增大，随海藻酸钠用量的增大而减小，当凝固浴用量4％、凝固时间达15s时，纤维的吸附能力达到饱和．     

Sodium Trends in Selected U.S. Total Diet Study Foods, 2003-2011

ObjectiveCharacterize trends in sodium concentrations in the general categories of foods analyzed in the U.S. FDA Total Diet Study (TDS) program from 2003 through 2011. Methods: Trends were assessed for sodium concentrations in a small convenience sample of TDS foods from 2003 to 2011 using simple linear regression with the SAS regression procedure, focusing on sodium concentrations in foods in USDA's sentinel food categories. Results: Levels of sodium in various TDS foods varied over time. Overall, 75 TDS foods did not have statistically significant linear changes in sodium content during that time, and 23 TDS foods did. Certain sentinel foods such as ramen-style noodles showed gradually increasing sodium content from 2003 through 2011. Significance: Over three quarters of foods show no statistically significant linear changes over time. Although a number of selected foods had a statistically significant decline, a limitation to this study is that specific brands of TDS foods were not necessarily the same for each period. The results suggest that some sodium reduction has been occurring in some foods and supports the idea that commercially viable reductions are possible. Such reductions in the sodium content of foods could have large public health implications—rates of hypertension and related health consequences would likely decline—thus saving thousands of lives and billions of dollars each year.     

Effect of Alkali Dipping on Dough and Final Product Quality

ABSTRACT: The effects of alkali dipping on starch, protein, and color changes in hard pretzel products have never been researched. Experiments were conducted to mimic reactions occurring on the pretzel dough surface. Dough was dipped in water or 1% sodium hydroxide solution at different temperatures between 50°C and 80°C. Protein and starch profile after dipping were analyzed. Color development on pretzel surface following the extraction of pigments from flour was investigated. Whole dough and pretzel samples were also made at pilot plant and the properties were analyzed. Only starch granules on the dough surface were gelatinized following dipping. Amylose-lipid complex dissociated at a lower temperature with alkali treatment but were not dissociated, even at high-temperature dipping in water. Treating the dough at 80°C in alkali solution resulted in the hydrolysis of proteins into smaller peptides that could be not precipitated by trichloroacetic acid (TCA). Dough surface color was different following pigment extraction from flour but not significantly different following baking. The results suggest that the color that developed on pretzel surface was not due to pigments present in the flour but was contributed by the reaction within or between the starch and protein hydrolysis derivatives during baking.