Influence of Dopants in ZnO Films on Defects

The influence of dopants in ZnO films on defects is investigated by slow positron annihilation technique. The results show S that parameters meet S_Al>S_un>S_Ag for Al-doped ZnO films, undoped and Ag-doped ZnO films. Zinc vacancies are found in all ZnO films with different dopants. According to S parameter and the same defect type, it can be induced that the zinc vacancy concentration is the highest in the Al-doped ZnO film, and it is the least in the Ag-doped ZnO film. When Al atoms are doped in the ZnO films grown on silicon substrates, Zn vacancies increase as compared to the undoped and Ag-doped ZnO films. The dopant concentration could determine the position of Fermi level in materials, while defect formation energy of zinc vacancy strongly depends on the position of Fermi level, so its concentration varies with dopant element and dopant concentration.     

新型蒽类聚方酸菁的合成及其性能

以蒽为起始原料,经溴代反应和Witting-Horner反应制得单体9,10-双[2-(1-辛基-1H-吡咯-2-基)乙烯基]蒽(3);3与芳酸缩聚合成了一个新型的蒽类聚方酸菁(4),其结构和性能经UV-Vis,1HNMR,13CNMR,IR,XRD,SEM和TG表征。4在氯仿中的λmax位于700nm;4为非晶态结构;4的初始分解温度为297.1℃。     

Hydrothermal Synthesis, Crystal Structure and Luminescent Properties of an Organically Templated 2-D Uranyl Sulfate

An organically templated 2-D uranyl sulfate, {（C2H8N）[（UO2）Cl（SO4）（H2O）] }n 1, has been hydrothermally synthesized. The crystal and molecular structures have been determined by X-ray crystallography method and spectral techniques. 1 belongs to monoclinic, space group P21/c with a = 8.3545（17）, b = 10.550（2）, c = 12.370（3）A, β = 102.64（3）°, V = 1063.9（4）A3, Mr = 464.64, De= 2.901 g/cm^3, F（000） = 836,μ = 15.710 mm^-1, Z= 4, the final R = 0.0286 and wR = 0.0685 for 10164 observed reflections with Ⅰ 〉 2σ（Ⅰ）. 1 presents a two-dimensional layer-like structure constructed from infinite anionic [（UO2）Cl（H2O）（SO4）]^- layers with [C2H8N]^＋ cations balancing the charge and a number of intermoleeular hydrogen bonds （C-H…O and O-H…Cl） existing in the solid state. The fluorescence properties of 1 have also been discussed.     

Mg助剂对Co/Mg/HZSM-5催化剂结构及其催化甲烷部分氧化制合成气性能的影响

采用XRD、TEM、H2-TPR、Raman、XPS和活性评价等方法, 研究了Mg助剂对Co/Mg/HZSM-5催化剂物理化学性质和甲烷部分氧化(POM)制合成气反应性能的影响. 研究发现, 在Co/HZSM-5催化剂中添加Mg助剂, 可有效地提高催化剂的催化活性和稳定性. 在750 ℃和空速1.0×10⁵ mL·h^-1·g^-1反应条件下, Co/Mg/HZSM-5在连续反应30 h的实验时间内催化活性稳定不变, 而Co/HZSM-5因其活性中心Co0转化生成CoAl2O4非活性相, 反应10 h后即迅速失活. 催化剂表征结果表明, 在Co/Mg/HZSM-5催化剂中钴物种除以Co3O4存在外, 一部分钴物种还与Mg助剂发生强相互作用生成较难还原的MgCo2O4, 由此导致还原后钴金属的分散度较高. 关联催化剂表征和活性评价结果, 讨论了催化剂结构与性能之间的关系.     

Investigation on High Efficient Catalysts for the Oxidative Dehydrogenation of Ethane

Since the pioneer work of Thorsteinson fot me ox(?) ethane, a series of V-Mo based catalysts mainly for the oxidative dehydrogenation of ethane have been patented. On the surfaces of these catalysts, a C_2H_4 selectivity of 70％ was achieved, but the space velocity was only about 340 h~(-1). Lunsford, et al. reported a C_2H_6 conversion of 75％ and a C_2H_4 selectivity of 76％ over the     

Study on the Excited States of 124Cs by Heavy Ion Reaction

Excited states of ¹²⁴Cs have been studied by means of in beam γ-ray technique via the reaction ¹⁰⁹Ag(¹⁹F,p3n).Based on the observation of the high spin bands and their decay to the ground state,a level scheme of ¹²⁴Cs has been established.     

D-葡萄糖与氯化稀土配合物的合成及红外光谱研究

以非水溶剂为介质合成了D-葡萄糖、氯化稀土、吡啶的混配多元配合物,并进行了元素分析和红外光谱测定。研究结果表明,D-葡萄糖和溶剂吡啶同时参与了配位,该配合物的组成为:Ln(C₆H₁₂O₆)(C₅H₅N)Cl₃(Ln=La,Ce,Pr,Nd,Sm等).本文还对配合物的可能结构进行了讨论。     

由光敏化环合反应合成若干取代菲啶

用苯乙酮做为光敏剂,从一系列2-溴-4,5-次甲二氧基-N-苯甲基取代苯胺4a～4d通过光环合反应合成了1,3,4-异丙氧基和2-甲基8,9-次甲二氧基菲啶5a～5d 4个目的化合物,与不使用光敏剂的光环合反应合成同样的取代菲啶相比较,结果表明光敏化环合反应不仅使产物5a～5d的收率明显提高,而且还合成了直接照射的光环合反应不能生成的1-异丙氧基-8,9-次甲二氧基菲啶5a。     

用离散混沌信号驱动实现混沌同步

提出了用离散混沌系统驱动连续混沌系统导致其同步的方法,以逻辑映象、Henon映象、Lorenz系统为例,数值地研究了这种混沌同步方法.模拟结果表明,当驱动信号的强度足够大时,可使两个连续混沌系统达到完全同步,且输出信号具有类似于白噪声的宽谱特性.同时研究了用该混沌同步方法实现保密通信的可能性. 关键词：     

有电荷转移络合物参与的共聚体系竞聚率

从有电荷转移络合物参与的共聚体系增长基元反应出,提出一种有ＣＴＣ参与的共聚体系竞聚率的求法,从中得到４个竞聚率,自由单体和ＣＴＣ的相对活性等信息。