实验室含铬废液处理方法的对比研究

实验室含铬废液不能直接排放,必须进行回收处理。采用化学还原法处理含Cr（VI）废液,对比研究了以亚硫酸钠、亚硫酸氢钠、抗坏血酸、硫酸亚铁为还原剂还原Cr（VI）的酸度条件、还原剂用量、反应时间等影响因素．结果表明：在最佳参件下,四种还原剂处理含Cr（VI）废液的去除率都在99．9％以上,处理后出水的Cr（VD浓度分别为0．048mg·L^-1、0．018mg·L^-1,0．038mg·L^-1,0．018mg·L^-1,均小于0．5mg·L^-1,达到了国家排放标准,取得了良好的处理效果。综合分析Cr（VI）~除率和经济效益得出亚硫酸氢钠为最佳还原剂。     

Enhancing polyphenol extraction from unripe apples by carbohydrate-hydrolyzing enzymes

The effects of process variables such as enzyme types, enzyme ratio, reaction temperature, pH, time, and ethanol concentration on the extraction of unripe apple polyphenol were investigated. The results indicated that Viscozyme L had the strongest effect on polyphenols extraction and was selected to study the polyphenol composition. The ratio of enzyme (Viscozyme L) to substrate (2 fungal beta-glucanase units (FBG)) at 0.02, reaction at pH 3.7,50 ℃ for 12 h, and ethanol concentration of 70% were chosen as the most favorable extraction condition. Total phenolic content (TPC), reducing sugar content (RSC), and extraction yield increased by about 3,1.5, and 2 times, respectively, compared with control. The contents of p-coumaric acid, ferulic acid, and caffeic acid increased to 8,4, and 32 times, respectively. The enzyme-aided polyphenol extraction process from unripe apples might be applied to food industry for enhancing bioactive compound production.     

酸雨对不同农作物种子萌发的影响

实验采用不同pH的模拟酸雨,研究其对玉米和绿豆种子萌发的影响.结果表明:pH=2.0时,玉米和绿豆均不发芽;pH=2.5时,只有异状发芽;pH≥3.0时,二者的发芽率,发芽势、发芽指数、活力指数、贮藏物质的的消耗率与运转率均随pH值的上升而增大;异状发芽率、芽长和根长的抑制指数则随pH值的增大而降低;酸雨胁迫下,绿豆各项指标的变幅都小于玉米的结果,表明绿豆抗酸雨胁迫的能力比玉米强.     

固体酸催化合成氯乙酸戊酯

固体酸是一种好的催化剂,它能够代替硫酸作为酯化催化剂．评述了对甲苯磺酸、磺酸盐、氨基磺酸、强酸性阳离子交换树脂、六水三氯化铁、五水四氯化锡、三氯化铝-硫酸铜复盐、结晶硫酸铝、一水硫酸氢钠、固体超强酸、杂多酸和分子筛等催化合成氯乙酸戊酯的合成方法．认为有机磺酸盐、氨基磺酸、强酸性阳离子交换树脂、结晶硫酸铝、一水硫酸氢钠、固体超强酸、杂多酸和分子筛等是合成氯乙酸正丁酯具有实用价值的催化剂．     

绿色硝化反应催化剂的研究进展

硝化反应是重要的有机反应,为替代传统工艺而进行的催化剂的研究成为该领域的热点.本文综述了近年来芳香族化合物的绿色硝化反应催化剂(固体酸和离子液体)的研究进展,简要评论了这些方法的特点.并展望了绿色硝化的研究方向.     

高效液相色谱法快速测定饮料中苯甲酸的方法研究

采用反相高效液相色谱法(HPLC)测定了饮料中的苯甲酸含量,建立了快速测定苯甲酸的方法.色谱条件为:流动相体系为甲醇与乙酸铵溶液(0.02mol/L),体积比为5:95,流速为1.0 mL/min,紫外检测波长为230 n m,柱温为25℃,进样体积为10μL.采用外标法定量,在5～100μg/ml范围内,回归方程相关系数为0.99999,检出限为0.38μg/mL.饮料中苯甲酸的加标回收率在97.80%～102.41%.按上述色谱条件平行测定样品5次,峰面积相对标准偏差(RSD)为0.1357%.说明方法的精密度高,重现性良好.     

Science Letters:Dechlorination mechanism of 2,4-dichlorophenol by Ni/Fe nanoparticles in the presence of humic acid

To understand the feasibility of its application to the in situ remediation of contaminated groundwater, the dechlori-nation of 2,4-dichlorophenol (2,4-DCP) by Ni/Fe nanoparticles in the presence of humic acid (HA) was investigated. We found that, as high performance liquid chromatography (HPLC) was used, the 2,4-DCP was first quickly reduced to o-chlorophenol (o-CP) andp-chlorophenol (p-CP), and then reduced to phenol as the final product. Our experimental results indicated that HA had an adverse effect on the dechlorination of 2,4-DCP by Ni/Fe nanoparticles, as the HA concentration increased, the removal rate decreased evidently. It also demonstrated that 2,4-DCP was reduced more easily to o-CP than to p-CP, and that the sequence of the tendency in dechlorination of intermediates was p-CP>o-CP. Transmission electron microscope (TEM) showed that HA could act as an adsorbate to compete reactive sites on the surface of Ni/Fe nanoparticles to decrease the dechlorination rate. Also we con-cluded that the dechlorination reaction of 2,4-DCP over Ni/Fe nanoparticles progressed through catalytic reductive dechlorination.     

Dechlorination mechanism of 2,4-dichlorophenol by Ni/Fe nanoparticles in the presence of humic acid

To understand the feasibility of its application to the in situ remediation of contaminated groundwater, the dechlorination of 2,4-dichlorophenol （2,4-DCP） by Ni/Fe nanoparticles in the presence of humic acid （HA） was investigated. We found that, as high performance liquid chromatography （HPLC） was used, the 2,4-DCP was first quickly reduced to o-chlorophenol （o-CP） andp-chlorophenol （p-CP）, and then reduced to phenol as the final product. Our experimental results indicated that HA had an adverse effect on the dechlorination of 2,4-DCP by Ni/Fe nanoparticles, as the HA concentration increased, the removal rate decreased evidently. It also demonstrated that 2,4-DCP was reduced more easily to o-CP than to p-CP, and that the sequence of the tendency in dechlorination of intermediates was p-CP〉o-CP. Transmission electron microscope （TEM） showed that HA could act as an adsorbate to compete reactive sites on the surface of Ni/Fe nanoparticles to decrease the dechlorination rate. Also we concluded that the dechlorination reaction of 2,4-DCP over Ni/Fe nanoparticles progressed through catalytic reductive dechlorination.     

手性Schiff碱金属配合物及其在不对称合成中的应用

近年来,Schiff碱金属配合物在不对称合成领域、光致变色领域、仿生科学领域等获得了广泛的应用.但目前的研究主要集中在Schiff碱类似物的合成及配合物的合成方面,今后的方向则主要应从研究机理出发,设计出具有很好活性的Schiff碱及其配合物,并研究其合成方法,最终形成规模化生产.     

红腹锦鸡和雉鸡肝脏抗氧化能力的比较

采用比色法测定了红腹锦鸡(Chrysolophus pictus)和雉鸡(Phasianus colchicus)肝脏的超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、碱性磷酸酶(AKP)和酸性磷酸酶(ACP)的活性及丙二醛(MDA)的含量.结果表明,红腹锦鸡肝脏SOD、CAT、ACP和AKP的活性均高于雉鸡,差异显著或极显著,MDA的含量低于雉鸡,差异极显著.可见,红腹锦鸡肝脏的抗氧化能力强于雉鸡.