用三个关系式与Mathematica软件求第二类自然数幂和公式

首先介绍三个第二类自然数幂和关系式并对其中的两式给出证明,接着利用这些关系式与数学软件M athem atica4.0,给出求解第二类自然数幂和公式的若干机械计算方法.     

新型金属杂冠醚配合物18-MC-6[Mn6(4-Amashz)6(DMF)6]·12DMF的合成

合成了一种新型金属杂冠醚配合物[Mn6(4-amashz)6(DMF)6]·12DMF,并用X射线衍射法对其结构进行了表征.研究了该化合物修饰金电极催化氧还原的性质,结果表明,该化合物具有平面碟状结构,对在碱性溶液中的氧有显著的催化还原作用.     

二次概周期系数微分方程的概周期解

利用指数二分性,Schauder不动点定理和Grownwall不等式证明了一类概周期系数微分方程的概周期解、有界解的存在唯一性及概周期解的全局吸引性.     

山奈黄素荧光分光光度测定痕量锗的新方法

锗与山奈黄素在H3PO4介质中发生配合反应, 形成配合比为2：1的配合物, 此配合物在乙醇溶液中具有很强的荧光强度, λex=438 nm, λem=478 nm. 用山奈黄素荧光分光光度法测定痕量锗, 检出限为0.15 μg/L, 线性范围为1.0～50 μg/L. 高、中、低3种浓度锗的相对标准偏差分别为 0.85%、 2.5%、 2.8%, 加标回收率为95.7%～103.9%.     

Relativistic Electromagnetic Solitary Wave in a Cylindrical Magnetized Plasma

In the presence of an applied static and uniform magnetic field, a cylindrical Kadomtsev-Petviashivili equation is derived for a relativistic electromagnetic solitary wave propagating in collisionless plasma consisting electrons, positrons, and ions in the case of weak relativistic limit. This equation is solved in a stationary frame to obtain explicit expression for the velocity, amplitude and width of solitons. The amplitude of the solitary wave has a maximum value at a critical αc of the ratio of the ion equilibrium density to the electron one, and it increases as the applied magnetic field becomes larger.     

Effect of Nonradiative Recombination on Carrier Dynamics in GaInNAs/GaAs Quantum Wells

The nonradiative recombination effect on carrier dynamics in GalnNAs/GaAs quantum wells is studied by timeresolved photoluminescence （TRPL） and polarization-dependent TRPL at various excitation intensities. It is found that both recombination dynamics and spin relaxation dynamics strongly depend on the excitation intensity. Under moderate excitation intensities the PL decay curves exhibit unusual non-exponential behaviour. This result is well simulated by a rate equation involving both the radiative and non-radiative recombinations via the introduction of a new parameter of the effective concentration of nonradiative recombination centres in the rate equation. In the spin dynamics study, the spin relaxation also shows strong excitation power dependence. Under the high excitation power an increase of spin polarization degree with time is observed. This new finding provides a useful hint that the spin process can be controlled by excitation power in GaInNAs systems.     

核糖体失活蛋白的应用研究进展

核糖体失活蛋白(ribosome-inactivating proteins,RIPs)是一类广泛存在于高等植物中能抑制核糖体翻译功能的毒蛋白.本文就核糖体失活蛋白在抗病毒、抗真菌、抗昆虫、抗肿瘤及艾滋病等方面的研究进展及应用作一综述.     

关于K-拟可加模糊积分的几点注记

在K-拟可加模糊积分定义及积分转换定理的基础上，证明这种模糊积分恰好构成K-拟可加模糊测度，并依据积分转换定理讨论这种K-拟可加模糊积分的一些补充性质。     

催化动力学光度法测定痕量铝

痕量铝在硝酸介质中能催化加速过氧化氢和高碘酸钾与二甲苯胺兰FF之间的褪色反应。研究了反应的最佳实验条件,建立了测定痕量铝的新方法。方法检出限为6.1×10-10gAl3+/mL,检测范围为0-1.0μgAl3+/25mL。本方法具有高灵敏度,选择性较好,操作简便,快速的特点。用以测定水样中的痕量铝,获得满意结果。     

Photoluminescence characteristics of ZnTiO3: Bi nanocrystals

The photoluminescence properties of the Bi³⁺ in sol-gel derived ZnTiO₃ nanocrystals have been investigated. An ultra-violet emission at 360 nm and a visible emission band at 506 nm have been observed, originating from two kinds of emission centers. The former is ascribed to the ³P₁-¹S₀ transition of Bi³⁺ and the latter to the recombination of the electrons with the photo-generated holes trapped in the zinc vacancies. In all cases the latter contribution is predominant.