<Emphasis Type="Italic">In situ</Emphasis> generation and detection of methyl radical by voltammetry

The chemistry of free radicals is one of the advanced subjects of fundamental sciences such as biomedicine, environment protection, new energy sources and new material. The detection technique of free radicals is an essential tool for studying free radicals. Methyl radical is one of the representatives of alkyl radicals and the studies on it attract more attention. The current approaches to obtaining methyl radical are based on pulse radiolysis of organic substances that contain the methyl gro…     

HACCP在灵芝酒生产中的应用

针对食品企业对食品质量与安全性的特别要求,利用食品安全管理体系,为生产灵芝酒的企业实行HACCP建立一套食品安全管理模型,通过危害分析确定9个关键控制点,为企业提高产品质量及安全性与增强市场竞争力提供理论依据.     

Photo Catalytic Oxidation of Alcohols in Water under Natural Weathering Conditions in the Presence of Bromo Source

1 Results The oxidation of alcohols into the corresponding carbonyl compound is one of the most important functional group transformation in organic synthesis[1]. Traditionally,such transformations have been performed with stoichiometric inorganic oxidant or other high valent metal oxidant[2]. Despite a variety of systems for the catalytic oxidation of alcohols have been developed,there is ongoing interest in the search for new efficient and environmental friendly oxidation system.To the best of our kno...     

N-(1,1-二甲基-3-氧代丁基)-2-丙烯酰胺的合成

以丙烯酰胺和二丙酮醇为原料,以浓硫酸为催化剂,合成了N-(1,1-二甲基-3-氧代丁基)-2-丙烯酰胺.采用红外光谱、核磁共振、熔点测定等方法对产物进行了表征.得到最佳反应条件为n(丙烯酰胺)∶n(二丙酮醇)∶n(浓硫酸)=2∶4∶1,反应温度为60℃,反应时间为6 h.得到产物的产率为20.0%,熔点为51~53℃.     

浅谈提高矿用提升钢丝绳寿命的方法

介绍了提高矿用提升钢丝绳寿命的几种方法,以期对煤矿的安全生产有一定的参考作用。     

用膜分离技术探析乙二醇加盐脱水法生产无水乙醇的关键技术

用工业无水乙二醇按一定的比例加入醋酸钾脱水法除去 96 .4 %乙醇中 4 .4 %的水份的操作技术关键是确保脱水塔内气—液两相逆流过程处在沸腾状态 ,即保证塔内形成液膜 ,减少汽流的阻力 ,使乙醇气体多次穿破液膜 ,而溶解—蒸发分离水份 ,最终从塔顶蒸发出合格的无水乙醇。用膜分离技术中的液膜、各种膜基平衡过程、膜蒸馏等新膜过程的相关理论探析乙醇脱水过程 ,比用传统的蒸馏理论去分析该过程 ,能更好地指导实际生产。     

Fabrication of porous alumina templates with a large-scale tunable interpore distance in a H_2C_2O_4-C_2H_5OH-H_2O solution

Highly ordered porous alumina templates with a large-scale tunable interpore distance (100―445 nm) have been successfully fabricated under an electric field of 40―180 V by modifying oxalic acid solution with adequate alcohol. The results under our experimental conditions show that the phenomena of burning and breakdown during the high-field anodization process can be avoided by adding a proper amount of alcohol to the oxalic acid solution. An excellent linear relationship between interpore distance and anodization voltage is obtained under 40―170 V, and the maximum anodization voltage that could be used to avoid burning and breakdown is 180 V.     

Fe(Ⅲ)-BPR-CPB-PVA显色反应的研究及应用

研究在溴化十六烷基吡啶(CPB)和聚乙烯醇(PVA)混和表面活性剂存在下，Fe(Ⅲ)与溴邻苯三酚红(BPR)的显色反应条件。结果表明，在pH值=4.0的醋酸醋酸钠缓冲溶液中，Fe(Ⅲ)与BPR生成的有色配合物的最大吸收波长为640 nm，表观摩尔吸光系数ε=5.33×104L*mol-1*cm-1，Fe(Ⅲ)浓度在0 μg/L～800 μg/L范围内符合比耳定律。据此拟定的分析方法用于水样、发样和某些化学试剂中微量铁的测定，获得满意结果。     

正丙醇-氯化钠-硫氰酸铵体系萃取分离Pd(Ⅱ)

研究了氯化钠存在下,正丙醇-硫氰酸铵体系萃取分离Pd(II)的行为.实验结果表明,Pd(II)与SCN-形成的Pd(SCN)42-很容易被萃取到正丙醇相中,当溶液中氯化钠、硫氰酸铵和正丙醇的浓度分别为0.20 kg.L-1、5.0×10-4mol.L-1、0.30 L.L-1,pH 2.5时,能使Pd(II)的萃取率达到99.5%以上,而Cd(II)、Cr(III)、Ni(II)、Al(III)、Fe(II)和Ga(III)等离子基本不被萃取,实现了Pd(II)与上述离子的分离.