主成分分析-二阶导数在中红外光谱定量分析中的应用

介绍了运用最小二乘法建立傅立叶变换中红外光谱定量分析模型的原理和方法。以苯甲酸和邻苯二甲酸氢钾为实验材料获取红外吸收光谱,采用MATLAB工程语言编程,分别以吸收光谱和二阶导数光谱为校正集样本,采用主成分分析方法对样本进行优选压缩,以建立了中红外光谱定量分析模型。用此模型预测混合物的含量,预测值与实际值的相对误差小于5.0%。     

氢化非晶硅薄膜的红外光谱分析和桥键氢扩散假设

通过红外透射光谱研究了在光诱寻退火中退火条件对氢化非晶硅薄膜的结构和光电特性的影响,实验所用样品采用热丝辅助微波电子回旋共振化学气相沉积方法制备。我们用桥键氢扩散模型来解释退火中的不同现象。样品的红外光谱在630和2000cm^-1处的吸收系数有所增加,说明了原先的成键氢发生了移动和溢出,我们认为通过光诱导产生栽流子的非辐射复合以及桥键氢和深俘获氢原子的交换,产生了大量的桥键氢原子,它们相互结合形成分子氢,氢溢出要优于氢团聚。     

二甲基硅油 C-Si 伸缩振动模式红外光谱研究

在303~393 K温度范围内,采用变温傅里叶变换衰减全反射红外光谱技术(ATR-FTIR)研究了二甲基硅油的一维红外光谱、二阶导数红外光谱、四阶导数红外光谱和去卷积红外光谱。实验发现,在1800~600 cm~(-1)范围内,二甲基硅油主要存在CH_3伸缩振动模式(νCH_3)、CH_3变形振动模式(δCH_3)、CH_3摇摆振动模式(ρCH_3)、Si-O伸缩振动模式(νSi-O)和Si-C伸缩振动式(νSi-C)等5种红外吸收模式,其中782 cm~(-1)和789 cm~(-1)处的红外吸收峰归属于二甲基硅油νSi-C。以二甲基硅油νSi-C为研究对象,进一步开展相关二维红外光谱的研究。结果发现,随着测定温度的升高,二甲基硅油νSi-C红外吸收强度的变化快慢顺序为:789 cm~(-1)782 cm~(-1)。本项研究拓展了ATR-FTIR技术在二甲基硅油热变性方面的研究范围。     

Chirp_z变换在红外光谱细化中的应用

用傅里叶红外光谱仪对红外光谱进行测量时得到的是整个波带内的光谱图,有时我们只关心某一波段的光谱图,这时就必须对光谱图进行细化.本文将Chirp_z变换方法用于红外光谱的细化,利用该方法的局部光谱细化能力,有效实现了红外光谱图的局部放大.该方法可以在采样点数不变的情况下实现任意波段范围内的红外光谱图的细化,同时由于局部范围内采样分辨率的提高,将获得更高精度的红外光谱图.理论推导和实验结果表明,Chirp_z变换具有精度高,速度快和灵活性强的特点,具有很高的工程应用价值.     

聚四氟乙烯F-C-F伸缩振动二维红外光谱研究

在303~393K的温度范围内,测定聚四氟乙烯F-C-F伸缩振动模式(νCF2)的一维红外光谱。研究发现:1220cm-1的红外吸收峰归属于聚四氟乙烯F-C-F不对称伸缩振动模式(νasCF2),而1150cm-1的红外吸收峰则归属于聚四氟乙烯F-C-F对称伸缩振动模式(νsCF2)。进一步研究了聚四氟乙烯νCF2的二阶导数红外光谱、四阶导数红外光谱,发现聚四氟乙烯νasCF2在1210cm-1和1260cm-1处裂分为双峰;而聚四氟乙烯νsCF2则在1145cm-1、1155cm-1和1175cm-1裂分为3个吸收峰。最后研究了聚四氟乙烯二维红外光谱,考察了温度对于聚四氟乙烯νCF2吸收强度变化的影响。研究发现:随着测定温度的升高,聚四氟乙烯νCF2红外吸收强度变化快慢的顺序为:1145cm-1>1210cm-1>1155cm-1>1175cm-1>1260cm-1。本项研究拓展了二维红外光谱在聚四氟乙烯热变性方面的研究范围。     

聚四氟乙烯F-C-F伸缩振动二维红外光谱研究

在303~393K的温度范围内,测定聚四氟乙烯F-C-F伸缩振动模式(νCF2)的一维红外光谱。研究发现:1220cm-1的红外吸收峰归属于聚四氟乙烯F-C-F不对称伸缩振动模式(νasCF2),而1150cm-1的红外吸收峰则归属于聚四氟乙烯F-C-F对称伸缩振动模式(νsCF2)。进一步研究了聚四氟乙烯νCF2的二阶导数红外光谱、四阶导数红外光谱,发现聚四氟乙烯νasCF2在1210cm-1和1260cm-1处裂分为双峰;而聚四氟乙烯νsCF2则在1145cm-1、1155cm-1和1175cm-1裂分为3个吸收峰。最后研究了聚四氟乙烯二维红外光谱,考察了温度对于聚四氟乙烯νCF2吸收强度变化的影响。研究发现:随着测定温度的升高,聚四氟乙烯νCF2红外吸收强度变化快慢的顺序为:1145cm-1>1210cm-1>1155cm-1>1175cm-1>1260cm-1。本项研究拓展了二维红外光谱在聚四氟乙烯热变性方面的研究范围。     

中红外光谱规则透射比量值比对

为保证量值准确、可靠,适应国内材料中红外规则透射比校准工作发展需要,以公正、科学地反映相关单位测量能力,客观、准确地复现各参加比对实验室的仪器设备的测量准确度程度以及考查其检定人员的技术水平,本文介绍了由中国计量科学研究院组织的中红外规则透射比的量值比对的相关情况.     

全自动红外探测器相对光谱响应测量系统

用付立叶变换红外光谱仪建立了一套全自动红外探测器相对光谱响应测量系统。该系统具有光谱范围宽（１～２５μｍ）、测量速度快、准确度高、操作简便等特点，应用前景广泛。     

聚丙烯C—H 弯曲振动二维红外光谱研究

目的通过二维红外光谱技术研究温度对聚丙烯化学结构的影响。方法在1500~1350 cm-1的频率范围内,分别测定聚丙烯C—H弯曲振动模式(δC-H)的一维红外光谱、二阶导数红外光谱和四阶导数红外光谱来确定聚丙烯分子结构,后采用二维红外光谱研究温度对聚丙烯δC-H红外吸收强度的影响。结果聚丙烯δC-H主要包括甲基不对称碳氢弯曲振动模式(δas CH3)、甲基对称碳氢弯曲振动模式(δs CH3)和亚甲基碳氢弯曲振动模式(δCH2),随着测定温度的升高,聚丙烯分子中δC-H红外吸收强度变化快慢顺序为δCH2-2(1464 cm-1)δCH2-1(1475 cm-1)δas CH3(1455 cm-1)δs CH3(1375 cm-1)。结论二维红外光谱在有机高分子包装材料热变性分析具有重大作用。     

氮化硼薄膜在退火相变中的应力研究

利用射频溅射系统在P型Si（100）衬底上制备氮化硼薄膜。对其进行600～1000℃的常压下N2保护退火。通过傅立叶变换红外谱（FTIR）分析，发现hBN-cBN-hBN的可逆相变。通过不同温度退火后立方相横光学振动模式峰位的移动，计算了氮化硼薄膜中残余应力的变化。发现沉积后退火很好地解决了高立方相氮化硼薄膜应力释放的问题，可提高立方氮化硼薄膜在硅衬底上的粘附性。并且探索性地讨论在退火过程中c-BN成核、生长与薄膜中应力变化的关系。     

猪跟腱胶原蛋白海绵的制备

目的为了更好利用猪跟腱资源,提高其附加值及拓宽胶原在包装方面的应用,探讨猪跟腱胶原蛋白海绵的制备及该海绵对乙醇的吸附作用。方法采用单因素实验考察猪跟腱胶原蛋白浓度、甘油含量、浇注厚度对力学性能的影响,并考察海绵孔隙率和时间对乙醇吸附性能的影响。结果当胶原的质量分数为1%,甘油的质量分数为0.6%,浇注厚度为5 mm时,制备的海绵抗张强度为210.91 k Pa,断裂伸长率为6.98%,此工艺条件下制备的海绵孔隙率为91.19%,30 d乙醇吸附量为416.32 mg/g,吸附量与海绵的孔隙率成正相关。结论猪跟腱胶原蛋白在此工艺下制备的海绵比其他动物胶原蛋白海绵的抗张强度高,且对乙醇具有吸附作用。     

Type I Collagen Immobilized Poly(caprolactone) Nanofibers: Characterization of Surface Modification and Growth of Fibroblasts

Poly(caprolactone) (PCL) electrospun nanofibers were modified by aminolysis and collagen was immobilized on the aminolysed PCL nanofibers. Considering low immunogenic response collagen elicits, immobilization of the same is anticipated to enhance the tissue engineering application of the PCL nanofibers. Amino groups were introduced into PCL nanofibers through aminolysis process. Aminolysis of PCL nanofibers was confirmed by electron dispersive X‐ray analysis (EDX). Collagen was immobilized on aminolysed PCL nanofibers using glutaraldehyde as crosslinker. The collagen crosslinking on to PCL nanofibers was established by attenuated total reflectance‐Fourier transform infrared (ATR‐FTIR) spectroscopy. The fiber morphologies of PCL nanofibers at different stages were characterized by scanning electron microscopy (SEM). The change in hydrophobicity of PCL nanofibers due to aminolysis and collagen immobilization was determined by water contact angle measurements. Aminolysis followed by collagen immobilization had reduced the intrinsic hydrophobicity of PCL nanofibers. NIH 3T3 fibroblasts were cultured for 2 days on PCL nanofibers, aminolysed PCL nanofibers, and aminolysed PCL nanofibers crosslinked with collagen. Cell attachment and growth were observed by MTT assay in each case. Collagen immobilization improved the biocompatibility of the PCL nanofibers. Thus the modified PCL nanofibers can be used as suitable broad spectrum scaffold for skin, cartilage, bone, cardiac constructs for efficient tissue engineering applications.     

Mass Spectrometric Study of Nanocrystalline ZnO Vaporization

The vapor composition over nano- and microcrystalline ZnO was determined between 450 and 1446 K by mass spectrometric Knudsen cell measurements. The results are used to evaluate the temperature-dependent pressure of atomic Zn, the upper limit of ZnO pressure, the lower limit of the enthalpy of sublimation ZnO(cr) = ZnO(g) at absolute zero, and the upper limit of the dissociation energy D ₀(ZnO).     

Mass Spectrometric Study of Vapor Composition over Germanium Telluride

The vapor phase over germanium telluride was studied by Knudsen cell mass spectrometric measurements. All of the signals in its mass spectrum were identified for the first time. The GeTe⁺, Te⁺ ₂, Te⁺, Ge⁺, and GeTe⁺ ₂ appearance potentials and temperature-dependent (700–850 K) GeTe and Te₂ partial pressures were refined (for the first time for GeTe₂). Conclusive evidence is presented that germanium telluride sublimes incongruently.     

Mass Spectrometric Study of Photoionization. I. Apparatus and Initial Observations on Acetylene,Acetylene-d2, Benzene,and Benzene-d6

A windowless vacuum ultraviolet monochromator and mass spectrometer are combined for the study of photoionization processes in the energy range 2000 to 600 A (6 to 21 eV). Details of the apparatus and techniques of operation are given and results are reported for an initial study of acetylene, acetylene-d₂, benzene, and benzene-d₆. Ionization energies of 11.406 and 11.416 eV are obtained for the 1π_u electron of C₂H₂ and C₂D₂, respectively. Vibrational levels of the ground state of the ion are observed with quantum intervals of 1855 cm⁻¹(C₂H₂) and 1775 cm⁻¹(C₂D₂). Ionization energies for the e_1g(π) electron of C₆H₆ and C₆D₆ are determined to be 9.24₂ and 9.24₅ eV, respectively. Quantum intervals for vibrational levels of the ground state ions are apparently equal for the two isotopic molecules and estimated to be 800 cm⁻¹. A second onset of ionization is observed at 11.5₃ eV for C₆H₆ and at 11.5₉ eV for C₆D₆. Results agree well with spectroscopic data.     

Study of the hydrolysis and condensation of γ-Aminopropyltriethoxysilane by FT-IR spectroscopy

The hydrolysis and condensation reactions of γ-APS have been studied in different acid content aqueous solution by using Fourier Transform infrared (FT-IR) spectroscopy. The hydrolysis of γ-APS under the studied conditions can be followed by the increase of the ethanol band located at 882 cm⁻¹ and the decrease of the band due to the ρ(CH₃) of γ-APS molecules located at 959 cm⁻¹. Hydrolysis reaction is faster by increasing both H₂O and acid concentrations, and it is completed when 3 moles of H₂O per mole of γ-APS are used. The increase of the vibrational band located at 1146 cm⁻¹ shows that condensation of the hydrolysed γ-APS molecules take place forming linear chains in poorly cross-linked structures. Besides, both 8-membered cyclic siloxane formations and poorly cross-linked structures are formed and increase as the water and acid content are increased. On the other hand, highly connected cross-linked structures do not appear due to the steric hindrance of the non-hydrolysable aminopropyl group. The silanol band shows that hydrolysis is faster than condensation except for samples with the lowest H₂O content.     

醛与胶原反应的研究

本文采用甲醛、乙二醛和戊二醛分别对酶解法提取的Ⅰ型胶原进行了化学修饰，研究了这几种修饰剂的pH值和浓度对修饰效果的影响。探讨了醛修饰胶原的机理并确定最佳工艺参数分别为：甲醛pH=9，浓度4％；乙二醛pH=9，浓度3％；戊二醛pH=6，浓度2％，三者所需浓度大小依次为甲醛〉乙二醛〉戊二醛。     

胶原与壳聚糖分子间的作用力

胶原与壳聚糖分子间的作用力使得其复合材料具有作为优良生物材料的潜力。文中通过稀溶液黏度法、红外和X射线衍射法对胶原与壳聚糖分子间作用力进行了表征。结果发现,任何比例的胶原与壳聚糖在分子级都是相容的,两者之间具有较强的相互作用。     

基于CS-SVM的山梨酸钾的荧光光谱检测法研究

通过分析山梨酸钾的橙汁溶液的荧光光谱特征,发现山梨酸钾在激发波长为375nm、发射波长为450～510nm范围的光谱图有毛刺,说明橙汁被激发的荧光会干扰山梨酸钾的荧光光谱。构建布谷鸟搜索算法（CS）优化支持向量机（SVM）模型对15个样本进行训练,并预测7个样本的山梨酸钾的浓度。CS-SVM的平均回收率为99.07%,均方误差为1.21×10^-5g/L,结果表明CS-SVM能够精确测定橙汁溶液中山梨酸钾的浓度,CS-SVM训练过程和对预测结果的平均回收率、误差都优于PSO-SVM和GA-SVM。