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.     

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.     

Protection of salvianolic acid B for human endothelial cells against hydrogen peroxide-induced oxidative damage

Salvianolic acid B(Sal B) is an active component of traditional Chinese medicine Salvia miltiorrhiza and is used to treat vascular diseases. To better understand its mechanism, the antioxidant capacities of Sal B was evaluated with human endothelial cells under oxidative stress. Human endothelial cells were pretreated with Sal B for 12 h followed by hydrogen peroxide for another 12 h. Production of reactive oxygen species (ROS), activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX), and concentration of glu-tathione were measured: Protective effect of Sal B on the endothelial cells from hydrogen peroxide-induced damage ' was observed, and ROS production in the cells was found significantly inhibited. Sal B remarkably enhanced the activities of antioxidant enzymes SOD, CAT and GPX. Furthermore, Sal B up-regulated the intracellular glutathione concentration. The results indicate that Sal B protected endothelial cells from oxidative stress by improving the redox status of the cells through enhancing the antioxidant enzyme activities and increasing the reductive glutathione concentration after the oxidative challenge.     

双吡啶分光光度法测定小麦植酸含量研究

本文建立了用硫酸铁铵-双吡啶比色法定量测定小麦植酸含量的一种新方法.在所述试验条件下,样品重为25mg,加热时间为30min能较好的测定出籽粒中的植酸含量,5次重复测定3个样品的相对标准偏差在0.92%～2.68%之间.内标试验表明,植酸的平均回收率约为97.3%,测定结果与三氯化铁比色法进行相关分析达极显著水平.因此,该方法可用于小麦籽粒中植酸含量的快速测定.     

均苯三甲酸铜配合物的合成和晶体结构

利用硝酸铜[Cu（NO3）2·6H2O]和均苯三甲酸在氨水溶液中反应,通过氨对铜（Ⅱ）离子的配合来调控配位反应速率,合成配合物{[Cu3（blc）2（NH3）（H2O）]·2H2O}n,并经元素分析和X射线单晶衍射法证实。配合物属单斜晶系,空间群为C2／c,晶体学参数：a=13．9213（5）,b=17．1210（6）,c=12．5271（5）A,V=2710．9（2）A3,Z=4。在标题化合物的结构中,Cu,离子为四配位而Cu2离子是五配位的,Cu1和Cu2被均苯三甲酸根离子桥联,由于均苯三甲酸根离子的结构中有C3对称轴而形成了二维六员环状平面结构,平面间通过N—H…0,O-H…0等氢键和π-π作用形成层状堆积。     

头孢他啶侧链酸活性硫酯的合成研究

头孢他啶侧链酸在碱性条件下与DM缩合生成头孢他啶侧链酸活性硫酯时,用价格低廉的亚磷酸三乙酯代替价格昂贵的三苯基膦,通过设计正交实验优选出的较佳反应条件为：固定头孢他啶侧链酸19．8g,反应物料n（头孢他啶侧链酸）：n（DM）：n（亚磷酸三乙酯）：n（三乙胺）=1：1．2：1．2：1．2,反应溶剂乙腈150mL,于5℃反应5h,收率86．8％．     

大鳍鱯繁殖期主要组织器官的氨基酸和脂肪酸组成

采用生物化学方法的方法,对大鳍鱯繁殖期的性腺、肝脏、肌肉的氨基酸和脂肪酸进行测定．结果表明：大鳍鱯雄性亲鱼精巢、肝脏和肌肉中,肌肉中氨基酸总量最高,为40．90g／100g;其次是精巢,为26．38g／100g;肝脏中含量最低,为18．38g／100g。从必需氨基酸占总氨基酸的比例来看,精巢最高,占53．41％;其次是肌肉,占52．93％;肝脏中最低,占51．96％。雌性亲鱼肌肉中氨基酸总量最高,为40．61g／100g;其次是卵巢,为22．42g／100g;肝脏中含量最低,为17．04g／100g。从必需氨基酸占总氨基酸的比例来看,卵巢最高,占52．85％;其次是肝脏,占51．76％;肌肉中最低,占49．OO％。从脂肪酸组成来看,雌雄亲鱼均为MUFA所占比例最高,其次是SFA,PUFA比例最小。雄鱼与雌鱼的三种组织器官中,所占比例较高的脂肪酸相似,它们是C18：1n．9（油酸）、C16：0（软脂酸）、C18：2n-6（亚油酸）和C16：1n-7（棕榈酸）。研究揭示了大鳍鱯繁殖期雌、雄亲鱼主要组织器官在物质构成上的特性。     

女子柔道运动的供能体系与训练生化原则初探

本文通过对女子柔道运动员比赛、训练中血乳酸、血糖及血尿素氮等生化指标的测试结果,分析探讨女子柔道运动供能代谢特点及运动训练的一般生化原则。旨在对制定训练计划及掌握运动量提供理论依据。     

醋酸/水分离研究进展

醋酸是一种重要的化工原料，其水溶液广泛存在于各类工业过程中,由于醋酸／水体系的相对挥发度不大，生产中用于分离醋酸／水的普通精馏和共沸精馏工艺能耗较高，因此研究者和工业界都在寻求更好的分离方法,目前醋酸／水的分离方法有精馏法、萃取法、醋化法、中和法、吸附法、膜分离法等，其中有些方法已经工业化，具有成熟的生产工艺；有些则处于研究阶段,本文对这些方法的研究现状及应用前景进行了介绍和评述，提出了萃取精馏法将是一很有前途的分离方法。     

γ-辐射对α-亚麻酸氧化反应的影响

对α-亚麻酸及其乙酯分别在氧气气氛和氮气气氛下进行一定剂量的γ-辐射，每隔两天测定其过氧化值。研究结果表明：辐射剂量和时间对亚麻酸的过氧化值有较大影响，本文同时探讨了亚麻酸在γ-辐射下过氧化值与反应机制之间的内在联系。