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本实验室已经报导过漫反射红外傳里叶变换光谱(DRIFT)用于研究粉末状煤炭的某些应用。纯煤的DRIFT光谱可在足够高的信噪比条件下测量。通常掩盖在比较宽的吸收带下的信息,可通过傅里叶自解褶积提取出来。因为煤是一种复杂的化学混合物,含有许多高分子量、多官能团的分子。煤的红外光谱通常呈现为由几个相当宽的无结构的吸收带组成,因此定量工作变得非常困难。我们发现,用傅里叶自解褶积与曲线拟合相结合来改善各个谱带的定量测量是一种可能的方法。本文中,我们要集中讨论如何通过改变每个组分的吸收峰的吸光度和半宽度而保持每个谱带的频率不变来解褶积时取得合成谱带的最佳的拟合。各个谱带的位置是用over-deconvolved光谱的重心法来确定的。文中以不同的氧化条件下,几种烟煤的漫反射光谱来举例说明这些技术。
Our laboratory has reported diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) for some applications in the study of powdered coal. The DRIFT spectrum of pure coal can be measured at a sufficiently high signal-to-noise ratio. Information that is usually masked under a wider absorption band can be extracted by Fourier self-deconvolution. Because coal is a complex chemical mixture, contains many high molecular weight, multi-functional molecules. Infrared spectra of coal usually appear to consist of several rather broad, unstructured absorption bands, so that the quantification work becomes very difficult. We found that it is a possible approach to improve the quantitative measurement of individual bands by combining Fourier self-deconvolution with curve fitting. In this paper, we will focus on how to obtain the best fit of the synthesized band when deconvolution is achieved by changing the absorbance and half-width of the absorption peak of each component while keeping the frequency of each band constant. The position of each band is determined by the center of gravity method of the over-deconvolved spectrum. In this paper, the oxidation of several different bituminous coal under diffuse reflectance spectra to illustrate these techniques.