A Convenient Synthetic Method of Metal Dendritic Porphyrins

Metal porphyrins are natural antioxidant reagent1-3. However, due to the characteristics of structures, they are only soluble in inorganic acids and part of polar organic solvents. Thus, it is limited to be used as effective pharmaceutical preparations. T…     

磁电子学器件应用原理

本文介绍几种重要的磁电子器件的基本结构和工作原理,包括巨磁电阻与隧穿磁电阻传感器、巨磁电阻隔离器、巨磁电阻与隧穿磁电阻硬盘读出磁头、磁电阻随机存取存储器、自旋转移磁化反转与微波振荡器。自旋晶体管作为未来磁电子学或自旋电子学时代的基本元素,目前大都还处在概念型阶段,本文也将对几种自旋晶体管的大致原理作简要介绍。     

现场拉曼光谱研究乙腈在金电极上的解离吸附行为

利用共焦显微拉曼系统、结合合适的电极表面粗糙方法研究了非水体系 0 1mol/LLiClO4 /CH3CN溶液中 ,乙腈分子在金表面的吸附和解离行为。结果表明非水体系中乙腈可在金表面发生还原反应 ,产物CN- 离子与电极表面作用形成的表面配合物可在较宽的电位区间吸附于电极表面。溶液中的微量水、激光照射以及电极电位均对该反应有较大的影响。通过拉曼谱图的比较得出乙腈分子解离出的CN- 在金电极表面比在银电极表面有更强的吸附作用。     

SPC数据采集与处理系统

SPC数据采集与处理系统实现了SPC数据的计算机采集与处理 ,大大提高了SPC分析的效率与准确性 ,对推动目前国内SPC应用 ,提高产品质量管理水平具有重要的现实意义。本文具体介绍了SPC数据采集与处理系统的结构与组成及软件实现和处理功能。     

Acoustic vector sensor signal processing

Acoustic vector sensor simultaneously, colocately and directly measures orthogonal components of particle velocity as well as pressure at single point in acoustic field so that is possible to improve performance of traditional underwater acoustic measurement devices or detection systems and extends new ideas for solving practical underwater acoustic engineering problems. Although acoustic vector sensor history of appearing in underwater acoustic area is no long, but with huge and potential military demands, acoustic vector sensor has strong development trend in last decade, it is evolving into a one of important underwater acoustic technology. Under this background, we try to review recent progress in study on acoustic vector sensor signal processing, such as signal detection, DOA estimation, beamforming, and so on.     

Ab Initio Study on the Isomerization and Dehydrogenation of Methylnitrene

The ab initio calculations were performed at the RHF/4-31G level with the reaction pathways of the iso-merization and dehydrogenation of methylnitrene by the intrinsic reaction coordinate method. The results show that the transformation from methylnitrene to methylenimine would be very easy. This accountes for the experimental fact that one couldn' t find the methylnitrene, but only obtained the methylenimine in the pyrolysis of methyl azide. The mode-selective study reveals the reaction coordinates (IRC) of isomerization and dehydrogenation of methylnitrene are associated with the molecular deformation mode of 1191 cm-1 and the methyl group unsymmetrical stretch mode, respectively. The coupling between normal coordinates is favourable to select the reaction channel of isomerization.     

Ce3+-冠醚配合物的紫外有机电致发光

采用5d-4f跃迁的稀土Ce³⁺-冠醚配合物(Ce-二环己基并-18-冠-6,Ce-DC18C6)作为发光掺杂剂,4,4'-二(9-咔唑基)联苯(CBP)为基质,设计制备了紫外发光器件:ITO/CuPc/Ce-DC18C6:CBP/Bu-PBD/LiF/Al,首次观测到峰位于376nm的Ce³⁺离子的紫外电致发光。通过对比器件的EL谱与Ce³⁺-冠醚配合物薄膜的PL谱发现,EL光谱中有部分来自Ce³⁺配合物中的Ce³⁺离子的。这种5d-4f电子跃迁的掺杂质量分数为3%时,该UV-发光器件的最大辐射功率为13μW/cm²。     

部分相干光束通过硬边光阑的推广光束传输M2因子

给出部分相干光通过硬边光阑后的强度二阶矩的计算公式，由此可得到部分相干光通过硬边光阑后的推广光束传输M^2因子。以部分相干高斯－谢尔模型光束为例，推导出相应的M^2因子，并作了数值计算和分析讨论。     

新疆红景天红色素的提取及理化性质的研究

对用索氏提取法和乙醇浸取法提取红景天红色素进行了比较，并探讨浸取的浓度，浸取温度等因素，指出了最佳生产工艺条件，从红景天中提取的天红色素是一种安全无毒的食用色素，本文还研究了几种食品添加剂对红景天红色素稳定性的影响，并对色素的耐氧化性进行了探讨，旨在为红景天红色素的开发利用提供有实用价值的信息。     

UV/H2O2氧化降解甲基叔丁基醚(MTBE)的试验研究

采用UV／H2O2技术对污染水体中的MTBE进行了氧化降解试验，考察了不同MTBE初始浓度，不同H2O2浓度，不同pH值，不同波长的紫外光对降解效果的影响，以及不同Cl^-、HCO3^-浓度的抑制作用．结果表明，在室温条件下，当紫外光波长为254nm，H2O2为15mmol／L，pH为3．0时对起始浓度为1mmol／L的MTBE具有较好的降解效果；反应60min，MTBE去除率可达97．6％．实验证明，UV／H2O2氧化技术是降解MTBE的一种有效方法．