饮用水中卤代乙酸测定方法的研究进展

对1994～2008年间饮用水中卤代乙酸测定方法的研究进展作了评述,涉及的主题有水样的采取和保存,以及多种可用于饮用水分析的方法,如气相色谱法(ECD检测)、气相色谱-质谱联用方法、离子色谱、毛细管电泳及一些在线控制检测方法等.对有关方法的发展也作了简要论述(引用文献40篇).     

不规则蜂窝材料在单向荷载作用下的蠕变屈曲分析

采用Norton蠕变理论和自由能守恒原理,分析了垂直与倾斜壁厚不等的非正六边形不规则蜂窝材料在面内单向应力作用下的蠕变屈曲行为,得到了蠕变屈曲临界应力与蠕变屈曲失效时间之间的函数关系.讨论了加载应力、初始缺陷、不规则蜂窝材料孔穴壁的厚度、长度与倾斜壁倾角对蠕变屈曲失效时间的影响.     

水中氯化物含量测量不确定度的评定

对硝酸银滴定法测定水中氯化物含量的测量不确定度进行评定。分析了测量重复性、滴定管、标准溶液浓度等因素对氯化物含量测量不确定度的影响。计算得水中氯化物含量测定结果的相对合成标准不确定度为3.4 9× 10 -3 。     

1-(5′-溴-2′-吡啶基)-5-4′-硝基苯基)-3-(2′-呋喃基)甲(月朁)的合成及其与锌显色反应的研究

甲■类试剂是有色金属离子的优良显色剂。它们的各种取代衍生物,有许多作为分析试剂已被研究。近年来,为了改善该类试剂的分析性能,在甲(?)骨架上接上吡啶、噻唑、眯唑及呋喃等杂环基团,合成了一系列不对称型的杂环甲(?)。 本文报导5-Br-PNPFF试剂的合成和提纯方法。研究了它与锌显色反应的条件,用     

Investigation of third-order nonlinear optical properties of two azo-nickel chelate compounds

This paper investigates the third-order nonlinear optical properties of two azo-nickel chelate compounds by the optical Kerr gate method at 830 nm wavelength with pulse duration of 120 fs. Both of the two compounds exhibited large third-order optical nonlinearity. The second-order hyperpolarizability,γ, of Compound 1 is of 1.0 × 10^-31 esu. Due to the charge transfer, the γ of Compound 2 with electron donor and acceptor group is 4.9 × 10^-31 esu, which is a four-time enhancement in comparison with Compound i. The absorption spectra show that the electron push-pull effect, which induces intramolecular charge transfer, leads to the increased optical nonlinearity.     

Bound states in the continuum in metal—dielectric photonic crystal with a birefringent defect

By using the difference of the band structure for the TE and TM waves in the metal—dielectric photonic crystals beyond the light cone and the birefringence of the anisotropic crystal, a one-dimensional photonic system is constructed to realize the bound states in the continuum (BICs). In addition to the BICs arising from the polarization incompatibility, the Friedrich—Wintgen BICs are also achieved when the leaking TM wave is eliminated due to the destructive interference of its ordinary and extraordinary wave components in the anisotropic crystal. A modified scheme favorable for practical application is also proposed. This scheme for BICs may help to suppress the radiation loss in the metal—dielectric photonic crystal systems.