光纤孤子在媒质突变界面的反射与透射

本文通过波包慢变假定,准单色近似和径向模式平均法,建立了光纤孤子反射和透射问题的支配方程和边界条件,借助光束传播法,数值模拟孤子在光纤单界面上的反射和透射过程,文中还给出数值实例。 关键词：     

用2D-NMR研究暗霉素T的化学结构

该文用NMR方法研究暗霉素T的化学结构.从1D谱和几种2D技术确认了暗霉素T是氨基糖苷类化合物.讨论了化合物的构型,并通过改变溶剂推断了氨基的连接位置.     

14β-甲磺酰氧基对映-贝壳杉二萜重排反应

本文研究了一类具有15-C与16-C单键的14β-甲磺酰氧基对映-贝壳杉烷(烯)(6,7和8)在Zn-EtOH体系中的重排反应, 它们均能重排成6, 7, 5, 5并环系统的化合物3, 12, 13a和13b。8重排时生成一个8-OEt化合物, 为这类化合物重排时经过阳离子中间体提供了一个证据。     

甲醇燃料车尾气净化催化剂的研究Ⅱ.甲醇深度氧化用银催化剂上吸附物种的原位红外研究

利用原位红外技术研究了ＣＨ３ＯＨ，ＣＯ，Ｏ２等在５％Ａｇ／γＡｌ２Ｏ３上的吸附情况及ＣＨ３ＯＨ和Ｏ２共吸附时表面物种的变化．结果表明，在表面纯净的Ａｇ／γＡｌ２Ｏ３催化剂上，甲醇的解离吸附仅发生在γＡｌ２Ｏ３上；表面预吸附氧后，可大大增强Ａｇ对ＣＨ３ＯＨ的解离吸附，当吸附的［ＣＨ３Ｏ］与［Ｏ］在Ａｇ／γＡｌ２Ｏ３上相互作用时，出现吸附态甲醛、甲二氧基、甲酸根等中间物种．Ｏ２在Ａｇ／γＡｌ２Ｏ３上存在非解离吸附（Ｏ－２），在真空中较易脱附，但在氧气氛下可于１００℃时稳定存在．     

谱任意的符号模式矩阵

一个n阶符号模式矩阵A称为是谱任意的,如果对任意的实系数n次首1多项式r(x),在A的定性矩阵类Q(A)中至少存在一个实矩阵B,使得B的特征多项式是r(x),文中证明了当n为奇数时n阶谱任意符号模式矩阵是存在的。     

Outline Imaging by THz Time Domain Spectroscopy

Outline imaging by THz time domain spectroscopy is proposed. Spectroscopic splitting at interface is reported, The principle of outline imaging is put forward. Experimental results demonstrate the feasibility of outline imaging by spectroscopic splitting, It is shown that clear out：line image of sample interface could be achieved easily by this technique. The spatial resolution is about 0.6mm. The THz-beam focus, the scanning step and the THz pulse width are the critical foctors affecting the imaging resolution. The signal-to-noise ratio of this technique could be improved greatly compared to the conventional transsion imaging.     

Infrared Spectroscopic Analysis of Chrysene and 1.2-Benzanthracence in Wax films

Chrysene and 1.2-benzanthracene are successfully doped in a solid wax film and their vibrational spectra in gooo--400cm^-1 are discussed. The harmonic frequencies and relative intensities of both the molecules observed in the film are compared with theoretical values calculated by the density functional theory （DFT） model as well as with the previous experimental data. The effects on spectra due to change of matrix and some additional bands observed in the wax film are also reported. Excellent agreement in the spectral positions and strengths between the experiments and DFT values are found.     

示波极谱法测定保健药品中的褪黑激素

褪黑激素与HNO3在室温下发生硝基化反应生成褪黑激素的硝基化合物,加NH3·H2O终止反应并用甲酸 甲酸钠缓冲液控制反应液pH3,在原点电位-0.20V(vs.SCE),测量-0.50V处的二阶导数峰高。方法检出限为1μg/L,线性范围为1μg/L～200μg/L,相对标准偏差为2.6%～8.0%,加标回收率为92 0%～110 0%,测定结果与高效液相色谱法进行比较,无显著性差异。