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基于色散校正的密度泛函理论的食品添加剂太赫兹光谱研究 被引量:3
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作者 李天莹 李春 +2 位作者 章龙 马卿效 蒋玲 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2021年第1期100-104,共5页
食品添加剂违规使用或滥用会对身体健康产生严重危害,相比于传统检测方法,太赫兹光谱技术具有检测周期短、准确率高等优势,被广泛应用于食品添加剂检测领域,但对其缺乏深入的理论分析。主要致力于根据晶体结构特征改进传统计算方法,提... 食品添加剂违规使用或滥用会对身体健康产生严重危害,相比于传统检测方法,太赫兹光谱技术具有检测周期短、准确率高等优势,被广泛应用于食品添加剂检测领域,但对其缺乏深入的理论分析。主要致力于根据晶体结构特征改进传统计算方法,提高食品添加剂模拟光谱预测精度并评估不同模型的计算性能。选取了三种富含氢键的食品添加剂,即苯甲酸、山梨酸和木糖醇,实验采用太赫兹时域光谱仪,理论计算采用CRYSTAL14软件包计算周期性晶体结构。鉴于富含氢键的体系中伦敦色散作用力不可忽略,在传统的Becke-3-Le e-Yang-Par(B3LYP)泛函和Perdew-Burke-Ernzerhof(PBE)泛函的基础上添加了伦敦色散校正系数,构建了B3LYP-D和PBE-D模型。计算得到吸收峰位平均绝对误差(AAE)分别为苯甲酸0.073(B3LYP-D)、0.096(PBE-D),山梨酸0.039(B3LYP-D)、0.047(PBE-D),木糖醇0.023(B3LYP-D)、0.087(PBE-D),相比于色散校正前的模型,AAE降低了0.03~0.1。对比了B3LYP-D和PBE-D模型的计算时长,B3LYP-D泛函耗时均为PBE-D泛函的二倍以上。结果表明,经色散校正后的模型适用于富含氢键的系统,能够提高模拟光谱预测精度,其中B3LYP-D模型预测精度更高但较为耗时,PBE-D泛函预测精度略低于B3LYP-D模型,但计算速度更快。振动来源分析表明,三种食品添加剂的振动模式均以晶格整体的平移和旋转为主,分子内的振动贡献较小。研究提出的色散校正模型对于其他类似体系的理论研究具有重要的参考价值。 展开更多
关键词 太赫兹光谱 食品添加剂 周期性晶体结构 氢键系统 色散校正
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New method of preparing 2D photonic crystals with big scale based on UV photosensitivity
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作者 LI Xia XUE Wei JIANG Yu-rong 《Optoelectronics Letters》 EI 2006年第5期361-363,共3页
A new method based on UV photosensitivity is proposed to fabricate big scale two dimensional photonic crystal.The optical transmission properties of designed periodic structure are investigated by numerical analysis.T... A new method based on UV photosensitivity is proposed to fabricate big scale two dimensional photonic crystal.The optical transmission properties of designed periodic structure are investigated by numerical analysis.The results show that the 2D photonic crystal fabricated by the new method has a desirable photonic bandgap of TE mode. 展开更多
关键词 二维光子晶体 光敏感性 周期结构 能带隙
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Elastic wave propagation and localization in band gap materials:a review 被引量:5
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作者 LI FengMing WANG YiZe 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2012年第10期1734-1746,共13页
Band gap materials(i.e.phononic crystals) are the artificially periodic structures,which have the stop band characteristic for elastic waves.The elastic waves will be localized in phononic crystals with defects,which ... Band gap materials(i.e.phononic crystals) are the artificially periodic structures,which have the stop band characteristic for elastic waves.The elastic waves will be localized in phononic crystals with defects,which results in the energy being accumulated around the defects.As a result,it is important to analyze the wave propagation and localization in band gap materials,especially for the structures consisting of smart materials.For example,with the mechanical-electro and mechanical-electro-magneto coupling,the phononic crystals consisting of piezoelectric and magnetoelectroelastic materials can be applied widely.This sets the theoretical basis for the design of band gap materials with multi fields coupling.This paper reviews the recent development of the elastic wave propagation and localization in both ordered and disordered band gap materials.The discussion focuses on the stop band and localization characteristics of elastic waves.Analytical methods and important results are also presented.Finally,some problems for further studies are discussed.This work aims to present the basic properties of wave band gaps in phononic crystals and wave localization in disordered periodic structures(e.g.phononic crystals with definite and random defects and phononic quasicrystals). 展开更多
关键词 band gap materials stop band characteristics DEFECT LOCALIZATION
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