咔咯锰(Ⅴ)氧配合物与苯乙烯的氧原子转移反应机理

采用密度泛函理论B3LYP方法研究了咔咯锰(Ⅴ)氧配合物(MnVO corrole)与苯乙烯氧原子转移(oxygen atom transfer,OAT)反应途径和吸电子取代基的影响.计算结果发现氧原子进攻苯乙烯中双键的β碳原子形成过渡态,结合内禀反应坐标法(intrinsic reaction coordinate ...     

基于KinPOS软件的BDS/GPS动对动相对定位性能分析

基于载波相位观测值的动对动相对定位可以得到双移动测站之间精确的相对位置关系,极大地扩展了动态相对定位的应用领域。GNSS精密动态定位、测速和定姿软件KinPOS针对动对动相对定位的质量控制方法进行优化,并基于三组不同场景下的实测GPS/BDS数据开展了动对动定位性能分析,结果表明:KinPOS软件解算结果稳定可靠,中短基线定位精度优于5 cm;BDS与GPS的动对动定位性能基本相当。     

A New Approach to C60-Containing Polyphosphazenes by Polymerization of Phosphonitrile Chloride Trimer in the Presence of C60

A novel synthetic strategy was developed to prepare polyphosphazenes containing C60 moieties. Thus, the phosphonitrile chloride trimer underwent thermal ring-opening polymerization （ROP） in the presence of C60 molecules to yield the reactive macromolecular intermediate, C60-containing poly（dichlorophosphazene）. And then, the other groups could be linked to the phosphazene backbone by nucleophilic substitution reaction of the chlorine atoms in this intermediate to produce a series of C60-containing polyphosphazene. The polymer exhibits good solubility in common organic solvents and is thermally stable.     

Pd/Al2O3催化剂催化毛竹与聚乙烯共裂解反应研究

我们采用等体积浸渍法制备了Al2O3负载贵金属Pd系列催化剂,分别在N2和H2气氛下,研究了不同Pd负载量的催化剂对毛竹和低密度聚乙烯(LDPE)混合物的催化裂解性能.实验结果表明:Pd的负载量为1.0%时,Pd/Al2O3催化剂在两种气氛下活性均较好,在H2气氛下所得到的油品中烯烃含量较低,异链烷烃和环烷烃含量较高,油品的收率和质量均明显优于在N2气氛下所得到的油品.XRD表征发现,Pd负载量为1.0%的催化剂上,Pd在Al2O3载体上生成了晶形,表明金属钯有利于毛竹和LDPE共裂解生成液体产物.     

新型超支化二阶非线性光学高分子：简便的合成方法和增强的非线性光学效应

通过简单的“A₂+B₃”反应，我们成功地合成了一个新的超支化非线性光学高分子。同时，作为对比，我们还合成了相对应的线型高分子。制备的两个高分子均溶于常见的有机溶剂，并由各种表征手段予以鉴定。超支化高分子的二阶非线性光学性能极大地优于相对应的线型高分子，表明超支化结构有利于提高高分子材料的宏观非线性光学效应。     

Accurate capacitance-voltage characterization of organic thin films with current injection

To deal with the invalidation of commonly employed series model and parallel model in capacitance-voltage (C-V) characterization of organic thin films when current injection is significant, a three-element equivalent circuit model is proposed. On this basis, the expression of real capacitance in consideration of current injection is theoretically derived by small-signal analysis method. The validity of the proposed equivalent circuit and theoretical expression are verified by a simulating circuit consisting of a capacitor, a diode, and a resistor. Moreover, the accurate C-V characteristic of an organic thin film device is obtained via theoretical correction of the experimental measuring result, and the real capacitance is 35.7% higher than the directly measured capacitance at 5-V bias in the parallel mode. This work strongly demonstrates the necessity to consider current injection in C-V measurement and provides a strategy for accurate C-V characterization experimentally.     

微波消解-火焰原子吸收法测定猪肝脏中的铅

采用微波消解—火焰原子吸收法对猪肝脏(鲜)中的痕量铅进行了测定,建立了一种微波消解样品、火焰原子吸收法测定猪肝脏(鲜)中痕量铅含量的方法.研究结果表明,在取样量为0.8g左右、HNO3(65％)∶H2O2(30％)=1∶1(体积比)、中等微波功率消解3 min的条件下,检测到猪肝脏中铅的含量为0.173 μ g/g.该...     

柱前衍生-高效液相色谱-荧光检测法测定罐头食品中的尿素

建立了罐头食品中尿素残留检测的柱前衍生-高效液相色谱-荧光检测方法.取5.0 g样品,经20 mL 1%(v/v)乙酸溶液提取、定容,离心后取上清液过滤,吸取0.5 mL提取液用呫吨醇进行衍生,采用高效液相色谱-荧光检测器进行测定.尿素在0.1~500 mg/L内线性良好,相关系数大于0.9995.实验表明,在5种罐头食品中各添加0.001~30 g/kg尿素,其平均回收率为80.2%~109.7%,相对标准偏差(n=6)为2.05%~6.53%,检出限为0.5 mg/kg,定量限为1.0 mg/kg.利用本研究建立的方法对168个实际样品进行测定,在3个肉类罐头样品中检出尿素,含量分别为10.6、62.1和2.6 mg/kg.方法稳定、可靠、操作简单,适用于罐头食品中尿素的检测.