Synthesis and Crystal Structure of [NdCl5(THF)]2-[HO-4,6-di-tBu-C6H2-2-CH2{CH(iPrNCHCHN)}]2+·THF

The title complex 1·THF has been synthesized by the reaction of [HO-4,6-di-tBu-C6H2-2-CH2{CH(iprNCHCHN)}]Cl with NdCl3 in a 2:1 molar ratio in THF, and characterized by single-crystal X-ray diffraction. It crystallizes in monoclinic, space group P21/c with a =9.6501(14), b = 16.393(2), c = 36.745(6) (A), β = 97.444(4)°, V = 5763.7(15)(A)3, Mr= 1124.69, Z =4, Dc= 1.296 g/cm3, μ(MoKa) = 1.175 mm-1, F(000) = 2348, the final R = 0.0729 and wR =0.1762 for 8735 observed reflections with I ＞ 2σ(1). Complex 1 consists of an anion [NdCl5(THF)]2- and two cations [HO-4,6-di-tBu-C6H2-2-CH2{CH(iprNCHCHN)}]2 to form a layer structure by the interconnection of anions and cations via hydrogen bonding. The central metal Nd in the anionic unit is coordinated by five Cl atoms and one oxygen atom from solvated THF molecule assuming a distorted octahedral geometry.     

基于综合特征的光纤周界安防系统高效入侵事件识别

在光纤周界安防系统中,急需对入侵事件实现准确而高效的识别,对事件特征做简练而恰当的描述是其关键所在.本文提出一种基于综合特征的入侵事件识别方法,该方法引入全相位滤波器组将输入信号并行分解为多个频率通道,以提取这些通道的归一化功率值;进而与信号过零率相结合,构成包含时域信息、频域信息的综合特征向量;最后将该特征向量馈入径向基函数神经网络即可准确识别出攀爬、敲击、晃动、剪切四种常见的入侵动作.实验证明,本文方法相比于现有的经验模态分解方法,不仅提高了精度,而且显著加快了识别速度.     

ZnS/g-C3N4复合型催化剂的制备及其可见光光催化性能

利用共沉淀的方法制备了ZnS/g-C3N4复合型催化剂,并考察其在可见光区对罗丹明B的光降解性能的影响机制.采用TEM、BET、XRD、ICP、FT-IR和XPS等分析手段表征了样品,并评价了样品的光催化活性.结果表明,与g-C3N4相比,ZnS负载量为5wt;的ZnS/g-C3N4催化剂活性会更高一些,且经过四次循环实验后样品的光催化性能未明显失活.这可能归因于ZnS和g-C3N4所形成的异质结构提高了光催化效率.     

胶束电动毛细管色谱同时测定食品中13种人工合成色素

建立了胶束电动毛细管色谱(MEKC)同时测定食品中10种水溶性和3种脂溶性人工合成色素的分析方法.应用正交法优化了缓冲溶液的pH值、硼酸浓度和SDS加入量,并研究了有机改性剂、分析电压、毛细管温度等对分离的影响.确定最佳电泳条件为:未涂层弹性石英毛细管柱(75 μm×58.5 cm),缓冲溶液为40 mmol/L硼酸-氢氧化钠(pH 9.5),加入20 mmol/L的SDS和30％的乙腈作改性剂,检测波长为220 nm,分析电压25 kV,毛细管温度25℃,进样压力50 MPa,进样时间5 s.在优化条件下,13种合成色素在3～200 mg/L范围内线性关系良好,r2均大于0.99.将该方法用于分析市售卤翅、腐竹、番茄酱、辣椒面等样品,其回收率为98％～104％,检出限为3.0～16.0 mg/L.该方法简便、准确,能够满足食品中合成色素的常规检测要求.