低含量高活性负载镍催化剂的制备及其加氢反应研究

以羰基镍为源, 制备了一系列高活性低含量负载镍催化剂. 采用BET、 XRD、 AAS和SEM等对催化剂进行表征. 以苯乙烯选择性加氢为探针反应, 考察了催化剂制备方法、镍含量、溶剂和反应温度、压力、时间对反应结果的影响. 结果表明, 用羰基镍制备的含镍为1%～5%的催化剂对苯乙烯的选择性加氢生成乙苯有很高的反应活性, 苯乙烯转化率和乙苯选择性分别达到了98%和99%以上.     

A new tripodal rhodamine B derivative as a highly selective and sensitive fluorescence chemosensor for copper(Ⅱ)

A new tripodal rhodamine B derivative 2 was designed and synthesized by tripodal trialdehyde and rhodamine B hydrazide for the first time. This derivative could be used as a fluorescent chemosensor for the selective and sensitive determination of copper(II) in Tris-HCl buffer and ethanol aqueous mixed media. Under the optimum conditions described herein,fluorescence enhancement at 557/577 nm was linearly related to the concentration of copper(II) in the range of 0.10 to 10.00×10-5 mol·L-1,with a corre-latio...     

PPESO3监测微波辅助酶解蛋白的进程

本实验将胰蛋白酶固定在荧光聚合物PPESO3上, 固定后的胰蛋白酶在酶解蛋白过程中通过监测荧光聚合物荧光强度的变化, 从而实现监测蛋白酶解过程.     

表面等离子体子共振传感器用于研究不同材质包裹的磁性纳米粒子性质

利用自行设计组装的以白色发光二极管为光源的表面等离子体子共振传感器实验装置, 检测了不同材质包裹的磁性纳米粒子连接靶向DNA与生物素化DNA探针的结合程度. 结果表明, 与聚苯乙烯磁性微球连接的靶向DNA相比, Fe3O4@SiO2核壳式纳米微球连接的靶向DNA与生物素化的DNA探针结合速率较快, 且其相对标准偏差较小.     

纳米核壳式铜-锡双金属粉的制备及性能研究

A kind of novel core-shell Cu-Sn bimetallic nanoparticles has been prepared by a new method (displacement method), in which Sn was made to cover on the surface of Cu nano-core. The preparation method and reaction mechanism have been discussed. This reaction happened under the existence of coordinate agent-(NH₂)₂CS and protective agent PVP. The nanoparticles prepared were with a core-shell structure, granule diameter between 50～100 nm and good dispersing capability. The Cu-Sn nanoparticles proposed has better oxidation-resistant ability than Cu nanoparticles with corresponding granule diameter and can be applied as lubricant additives as well as antibacterial agent. When the additive amount is very low (0.1wt‰～0.5wt‰), it can improve the P_B of the lubricant by 92%～106%, and also enhance its antiwear characteristics and friction-reducing properties. At the concentration of 1 000 ppm, it can reach an antibacterial ratio of 99.99%.     

无溶剂超声辐射下硝酸镱高效催化合成 1,4-二氢吡啶衍生物

在Yb(NO₃)₃催化下, 芳香醛、 5,5-二甲基-1,3-环己二酮、 乙酰乙酸乙酯和醋酸铵在室温无溶剂条件下经超声辐射一锅法合成了一系列1,4-二氢吡啶衍生物, 反应时间为15~35 min, 产率为86%~97%. 该方法具有条件温和、 反应时间短且产率高的优点. 催化剂Yb(NO₃)₃对环境友好且可循环使用, 为此类化合物的合成提供了一种有效的新方法.     

超高效液相色谱-串联质谱法测定肉制品中8种雌激素残留量

提出了超高效液相色谱-串联质谱法测定肉制品中8种雌激素(辛基酚、壬基酚、双酚A、己烯雌酚、雌酮、17β-雌二醇、17α-乙炔雌二醇和雌三醇)含量的方法。样品经乙酸乙酯提取两次,过HLB固相萃取柱净化后,将洗脱液氮吹至近干,残渣用甲醇-水(1+9)溶液溶解。采用AC-QUITYTMBEH C18色谱柱分离,用含0.1%(体积分数)甲酸的5mmol.L-1乙酸铵溶液和甲醇组成的流动相梯度洗脱。质谱测定中采用负离子电离方式,多反应监测模式。方法检出限(3S/N)在0.2～0.3μg.kg-1之间。方法的回收率在76.2%～108.3%之间,测定值的相对标准偏差(n=6)为4.3%～11.7%。     

A Sterically Hindered Zirconocene Complex (1,2-Ph2C5H3)2ZrCl2:Synthesis, Structure and Properties as Olefin Polymerization Catalyst

SinceKaminskyeIal.discoveredthehighlyactivezirconocenedich1oride/methyl-aluminoxane(MAO)catalyticsystemforolefinpolymerization',intensiveresearchworkhasbeenfocusedondevelopingnewgroup4metal1ocenecatalystsforimprovingcatalystactivitiesandpolymerproperties"'.Inthedevelopmentofnewmetallocenecatalystsystems,liganddesignandmodificationhaveplayedanimportantrole.lthasbeenknownthatevenminormodificationofagivenligandframeworkcouldresultinsignificantchangesincatalystactivitiesandpolymerproperties'.Int…     

大亚湾沉积物中氨基酸的垂直分布棗沉积物柱样W0中的游离氨基酸

用邻苯二甲醛（OPA）－3－巯基丙酸（3－MPA）柱前衍生高效液相色谱法测定了采自大亚湾近岸海域的一个长60cm的沉积物柱样W0中15种游离氨基酸（FAA）的含量，结果表明，W0中FAA总量在0．83－2．69mmol/kg之间，15种FAA以及FAA总量均随深度而以指数曲线降低，对氨基酸组成的分析表明，天冬氨酸，甘氨酸，组氨酸和苯丙氨酸的摩尔分数随深度而上升，苏氨酸，精氨酸，缬氨酸和异亮氨酸的摩尔分数随浓度而下降，其他氨基酸的摩尔分数随深度无显著变化，甘氨酸，丙氨酸，天冬氨酸，谷氨酸，丝氨酸是W0中含量最丰富的氨基酸，其摩尔数依次为28．1％，16．0％，14．7％，10．6％和7．2％。     

高效液相色谱法测定海洋水体与沉积物中光合色素

建立了海洋水体与沉积物中30种光合色素的反相高效液相色谱检测方法。海水滤膜和沉积物分别采用95%甲醇和95%丙酮超声萃取。萃取液混合一定比例的超纯水后,采用Eclipse XDB C8反相柱进行分离,以乙腈(A)、甲醇(B)和四丁基羟胺-甲醇(C)混合液为流动相进行洗脱,检测波长为430,440和450nm,柱温为50℃。色谱分离梯度为:0min,100%C;22min,25%A,45%B和30%C;28～38min,70%A,20%B和10%C;38.1～40min,100%C。对23种已知浓度色素的线性关系、检出限和加标回收率进行分析。结果表明,相关系数范围为0.9972～0.9998,检出限范围为0.0305～0.7740ng,加标回收率范围为88.6%～103.3%。