关于N(a,B)一个特性的初等演证

用较初等的方法演证了多元正态分布的一个特性,即N(a,B)可由其前二阶矩完全确定.     

警力分配问题中的模糊优选动态规划法

根据市区公安分局基层警力的分配问题的特点,将模糊优选理论与动态规划法相结合建立了多维多目标模糊优选动态规划模型,用此模型对警力进行合理分配,以得到最优警力分配方案,为公安决策者在警力分配问题中提供科学的理论依据.     

One- and Two-Photon Excited Fluorescence of CdSe and CdSe/ZnS Quantum Dots in n-Hexane

One- and two-photon absorption and excited fluorescence of the CdSe and the core-shell structure CdSe/ZnS quantum dots （QDs） in n-hexane is investigated. The linear and nonlinear absorption coefficients are measured and the two-photon-absorption cross sections of the QDs are also obtained. For both one-photon fluorescence and two-photon fluorescence, the emission efficiency of CdSe/ZnS is much higher than that of CdSe, originating from the effective surface passivation of the core-shell structure.     

Highly Emcient Dye-Sensitized Solar Cells Using a Composite ElectrolyteConsisting of LiI（CH3OH）4-I2, SiO2 Nano-Particles and an Ionic Liquid

Solid-state electrolyte LiI(CH3OH)4-I2 is used in dye-sensitized solar cells (DSSCs). The DSSCs using only the LiI(CH3OH)4-I2 electrolyte show very poor performance due to the quick crystal growth of LiI(CH3OH)4. In order to improve the performance of DSSCs, we prepare a composite electrolyte by adding Si02 nano-particles and an ionic liquid, 1-methyl-3-ethylimidazolium iodide, into the original solid-state electrolyte. High efficiency of 4.3% is achieved by applying this composite electrolyte to DSSCs.     

稳定同位素在药物动力学研究中的新进展

综述了稳定同位素在药物动力学研究中的最新发展，随着质谱和色－质联用等仪器的普及，它将成为药物研究中的一种重要手段． The recent progress of the Stable Isotopes(SI) research on pharmacokinetics is reviewed. With development of MS and GC MS, it will be an important method for studying drugs.     

氧化石墨烯/硫杂杯芳烃复合材料富集分离-石墨炉原子吸收法测定痕量铊

自制了一种新型氧化石墨烯/硫杂杯芳烃复合材料,用扫描电镜、红外光谱、元素分析、热分析对合成产品进行表征,用于痕量铊的富集,提出了氧化石墨烯/硫杂杯芳烃复合材料分离预富集,石墨炉原子吸收光谱法测定痕量铊的一种新方法,探讨了溶液pH值、温度、洗脱条件及干扰离子对痕量铊分离富集的影响,结果发现该材料对Tl3+具有较大吸附量。在pH 8.0,温度为(23±1)℃条件下,铊可被该材料定量吸附,其吸附容量为73.1 mg/g。吸附的铊可被5.0 mL酸性硫脲(0.5 mol/L HCl+1.0 mol/L硫脲)完全洗脱,方法的线性范围为0.012~15μg/L,检出限(3σ)为0.008μg/L,对0.50μg/L Tl3+工作液测定的RSD(n=7)为2.3%,加标回收率为93.6%~104.1%。此法用于生物样品和环境水样中痕量铊的测定,结果满意。     

“MM教育方式”的教学评价问题

编者按本刊文［１］～［４］的相继发表，为介绍和推广“ＭＭ教育方式”起了一定积极作用，受到读者的广泛关注．为了进一步深入作好“ＭＭ教育方式”的有关工作，我们再次“配套”推荐本文，以飨读者．１本文讨论的主要是在“ＭＭ教育方式”的推广和应用性实验中的教学评...     

锂离子电池正极材料层状LiMnO2的掺杂改性

层状LiMnO2具有成本低、无毒和比容量高等优点，是一种非常有发展前景的正极材料。本文介绍了近年来国内外层状LiMnO2的研究进展。主要阐述了层状LiMnO2的结构与性能的关系。结合笔者的工作，着重探讨了离子掺杂改性对层状LiMnO2的电化学性能的影响。最后，简要指明了层状LiMnO2将来的可能研究方向。     

Spectroscopic Study on Interaction of Lomefloxacin with Human Serum Albumin in the Presence of Copper Ion

The interaction of lomefloxacin （LMF） with human serum albumin （HSA） in the presence of copper ions in a physiological medium and its thermodynamic characteristics were investigated by multi-spectroscopy. The experimental results showed that both LMF and LMF-Cu^2＋ could quench the fluorescence of HSA with a static quenching mechanism, indicating that LMF or LMF-Cu^2＋ could react with HSA. The apparent binding constants/numbers of binding sites were estimated as 4.924± 105 Lomol 1/1.473 for LMF-HSA, 8.990± 104 L·mol^-1/1.785 for LMF- Cu^2＋-HSA, 1.10± 105 L·mol^-1/1.21 for LMF-Cu^2＋ and 7.30± 102 L·mol^-1/0.82 for HSA-Cu^2＋, respectively. AH and AS for LMF-HSA system were calculated to be --2.189 kJ·mol^-1 and 61.25 J·mol^-1·K^-1, while those for LMF-Cu^2＋-HSA system were -7.401 kJ·mol^-1 and 47.63 J·mol^-1·K^-1 Although the values of AH and AS in these two systems were different, the treads were similar, which indicated that electrostatic interactions in these two systems played a major role. According to Forster theory, the distances were given as 5.006 nm for HSA-LMF and 4.709 nm for HSA-LMF-Cu^2＋. Synchronous fluorescence and circular dichroism spectra confirmed further that the conformations of human serum albumin before and after interacting with LMF or LMF-Cu^2＋ were different. All the results revealed that copper ions promoted the interaction of lomefloxacin with human serum albumin.     

SWIP—PFP装置反场箍缩位形研究

ＳＷＩＰ－ＲＦＰ装置是具有金属真空室的环形反场箍缩（ＲＦＰ）装置。在初始气压，初始环场，可控辅助反场和等离子体自反效应的不同情况下，做了反场建立条件的实验。在有自反效应和可控辅助反场时间配合的三种运动情况下，反场箍缩放电已实现。本文给出了反场箍缩位形实验预测的结果，实验测出反场箍缩位形的等离子体电幅值，脉冲长度与相关因素的依赖关系。实验结果表明在无功率短路情况下，等离子体存在时间τｐ≥０．３ｍｓ。