STRUCTURAL PHASE TRANSITION OF ALIPHATIC NYLONS VIEWED FROM THE WAXD/SAXS AND VIBRATIONAL SPECTRAL MEASUREMENTS AND MOLECULAR DYNAMICS CALCULATION

The crystalline phase transition of aliphatic nylon 10/10 has been investigated on the basis of the simultaneous measurement of wide-angle and small-angle X-ray scatterings, the infrared spectral measurement and the molecular dynamics calculation. An interpretation of infrared spectra taken for a series of nylon samples and the corresponding model compounds was successfully made, allowing us to assign the infrared bands of the planar-zigzag methylene segments reasonably. As a result the methylene segmental parts of molecular chains were found to experience an order-to-disorder transition in the Brill transition region, where the intermolecular hydrogen bonds are kept alive although the bond strength becomes weaker at higher temperature. The small-angle X-ray scattering data revealed a slight change in lamellar stacking mode in the transition region. The crystal structure has been found to change more remarkably in the temperature region immediately below the melting point, where the conformationally disordered chains experienced drastic rotational and translational motions without any constraints by hydrogen bonds, and the lamellar thickness increased largely along the chain axis. These experimental results were reasonably reproduced by the molecular dynamics calculation performed at the various temperatures.     

基于极端积算子的LL型模糊数的最小一乘回归

针对模糊输入和模糊输出数据系统中的回归分析问题,考虑到系统中依赖关系不确定性特点以及模型稳健性和求解准确性等需求,建立一个模糊最小一乘优化模型。首先利用能诱导出LL型模糊数乘法保形运算的唯一T-模,即极端积算子,结合扩张原理,给出LL型模糊数间加法和乘法的运算规则。其次,基于LL型模糊数间的完备距离,得到模糊线性回归模型的参数估计,由此给出考虑清晰参数或清晰输入的两个简约模型及相应参数估计。通过计算Kim & Bishu测度、贴近测度和输出展形差异测度,比较与其他7种回归方法的优劣,并由模型的敏感性分析,充分说明本文算法的有效性和稳健性。