Theoretical Study on Hydrogen Interaction between 5-Fluorouracil and Glycine

The geometries,electronic structure,IR spectrum and other properties of hydrogen interaction between 5-fluorouracil and glycine were studied at the B3LYP/6-31+G* level.Single point energy calculations were executed at the B3LYP/6-311++G** and B3LYP/aug-cc-pvdz levels,and natural bond orbital (NBO) analysis was carried out at the B3LYP/6-31+G* level.Finally,the hydrogen bonds were discussed via AIM electronic density topology analysis.     

5-(5-碘-2-吡啶偶氮)-2,4-二氨基甲苯分光光度法测定微量钌(Ⅱ)

研究了新合成试剂5-(5-碘-2-吡啶偶氮)-2,4-二氨基甲苯(5-I-PADAT)与钌(Ⅱ)的显色反应。实验表明,在30%乙醇存在下于pH 4.0~6.2 HAc-NaAc缓冲介质中,钌(Ⅱ)与5-I-PADAT形成稳定的配合物,其最大吸收波长位于529 nm。该配合物在无机酸(HCl,H2SO4,HClO4,H3PO4)作用下,可转变为另一种具有较高吸收特性的配合物,其最大吸收波长位于509 nm,适宜的酸浓度范围分别为0.15~0.60 mol/L HCl,0.15~0.48 mol/L H2SO4,0.15~0.48 mol/LHClO4和0.15~0.90 mol/L H3PO4。表观摩尔吸光系数5ε09=5.72×104L.mol-1.cm-1,钌含量在0~0.5μg/mL内符合比尔定律。40倍的银、10倍的锇、6倍的金和4倍的Pt、Rh、Ir等贵金属离子不干扰钌的测定,钯的干扰可利用其与钌(Ⅱ)显色温度和酸度的差异性消除。方法可用于催化剂中微量钌的测定。     

新型双β-二酮、邻菲罗啉和铕(Ⅲ)三元配合物的合成与发光

合成了一个新型双β-二酮有机配体1,3-双[3-(2-噻吩基)-3-氧代丙酰基]苯、邻菲罗啉和铕的三元配合物,并应用红外光谱、紫外-可见光谱、元素分析和热重-差热分析等对配合物进行了组成确定和结构表征.荧光分析结果表明,配合物612 nm处的发射光谱为中心离子Eu3+的特征红光,属5D0→7F2跃迁带,峰形尖锐,单色性...     

不同半光强角对医用LED阵列灯珠间距影响的仿真研究

 讨论LED光源的半光强角对LED之间的最大间距的影响,采用Matlab软件对LED单元照度数据进行计算及仿真,给出相应的仿真图形。仿真结果表明:LED光源之间的最大间距与其功率无关,由于仿真的结果与理论计算值相吻合,说明在计算中所建立的LED的光学模型具有较高的可信度,所得结果为LED多阵列（如圆形,矩形,椭圆等）的仿真及应用设计奠定了理论基础。     

Progress in improving thermodynamics and kinetics of new hydrogen storage materials

Hydrogen storage material has been much developed recently because of its potential for proton exchange membrane (PEM) fuel cell applications. A successful solid-state reversible storage material should meet the requirements of high storage capacity, suitable thermodynamic properties, and fast adsorption and desorption kinetics. Complex hydrides, including boron hydride and alanate, ammonia borane, metal organic frameworks (MOFs), covalent organic frameworks (COFs) and zeolitic imidazolate frameworks (ZIFs), are remarkable hydrogen storage materials because of their advantages of high energy density and safety. This feature article focuses mainly on the thermodynamics and kinetics of these hydrogen storage materials in the past few years.     

船用超声液位传感器的分析与设计

介绍了一种船用某型超声液位传感器的基本结构和工作原理。在对脉冲式超声探头的轴向声压分布特点及其声透射强度分析研究的基础上,给出了该传感器的超声信号发射端与接收端之间距离d和压电晶片保护膜的壁厚δ值的确定方法。最后设计了一套超声液位传感器性能测试实验平台,对上述理论研究结论进行了实验验证。     

Comment on phase conventions in helicity formalism

Using the sequential decay process m e⁺e^- → J/ψ → ΛΛ, Λ → pπ^-, Λ → pπ⁺ as an example, the procedure for deducing the full angular distribution is illustrated by adopting both the Jacob-Wick and Jackson conventions in the helicity formalism. To make sure that the final physical result is free of phase conventions, we point out that the coefficients that relate the angular momentum states in different coordinate systems of reference frames have to be taken into account properly in the procedure. The fact that those coefficients are constants suggests that the Jackson convention is favorable in dealing with the processes with sequential decays.     

A viable method for goodness-of-fit test in maximum likelihood fit

A test statistic is proposed to perform the goodness-of-fit test in the unbinned maximum likelihood fit. Without using a detailed expression of the efficiency function, the test statistic is found to be strongly correlated with the maximum likelihood function if the efficiency function varies smoothly. We point out that the correlation coefficient can be estimated by the Monte Carlo technique. With the established method, two examples are given to illustrate the performance of the test statistic.     

1-(4-磺基苯)-3-(6-溴-苯并噻唑)-三氮烯合成及与钴(Ⅱ)的显色反应研究

合成了一种新试剂1-(4-磺基苯)-3-(6-溴-苯并噻唑)-三氮烯(SPBMBTT),并研究了在非离子表面活性剂Tween-80存在下与钴(Ⅱ)的显色反应。在pH 11.3的Na2CO3-HCl缓冲溶液中,试剂与钴(Ⅱ)形成配合比为1∶2的橙红色配合物,用双峰双波长法测定,其表观摩尔吸光系数ε=2.29×105L.mol-1.cm-1,钴(Ⅱ)含量在0~240μg/L范围内符合比耳定律。此法已用于vita-min B12针剂和茶叶中微量钴的测定,结果满意。