原子尺度上的异质催化

现实中的催化剂是个相当复杂的系统体系,且为粉末状,限制了多种表面科学表征手段的应用.科学家通过建立简化的催化剂模型,充分利用目前多种有力的科技分析手段,如扫描隧道显微镜(STM)、透射电镜(TEM)、光电子能谱(XPS)、傅里叶变换红外吸收谱(FTIR)、电子能量损失谱(EELS)等,直观地在原子尺度上研究催化反应的机理,从而使得人们能够设计出选择性能更高、催化性能更好的催化剂.     

直肠癌和直肠正常组织的傅里叶变换红外光谱研究

利用傅里叶变换中红外 (FTIR)光纤和ATR技术研究了 2 1例直肠癌病人的正常和癌变组织。对319张光谱进行数据分析的结果表明 ,五个相对峰高 (I2 873 I2 854,I1 74 5 I1 6 43,I1 458 I1 40 0 ,I1 2 4 0 I1 31 5和I1 1 6 2 I1 0 82,单位为cm- 1 )的差别可用于区分直肠癌和直肠正常组织。用这一差别分析了距离直肠癌 1cm处组织的光谱 ,发现该组织处于正常和癌变的过渡状态。     

Si衬底上生长的MnSi薄膜和MnSi1．7纳米线的STM和XPS分析

本文采用分子束外延方法制备出MnSi薄膜和MnSi1．7纳米线,利用扫描隧道显微镜进行观察,采用X射线光电子能谱仪系统地分析了MnSi薄膜和MnSi1．7纳米线的Mn2p和Si2p．结果表明厚度为-0．9nm的MnSi薄膜表面为／3×／3重构,MnSi1．7纳米线长50ff--1500nm,宽16—18nm,高-3nm．MnSi薄膜的Mn2p1／2和Mn2p3／2峰位与MnSil．7纳米线相同,均分别为649．7eV和638．7ev结合能在640-645eV和-653．8eV处的锰氧化合物的Mn2ps／2和Mn2p1／2峰证明在短暂暴露于空气中后MnSi薄膜和MnSi1．7纳米线表面有氧化层形成．相对于纯si的si2p谱,两种锰硅化合物的Si2p谱向低结合能方向发生了位移,表明随着锰硅化合物的形成Si的化学环境发生了变化．     

人肺组织与肺癌组织FTIR光谱的统计分析

本文应用统计方法分析了人肺正常组织和肺癌组织的FTIR光谱 ,选择光谱谱型参数 ;峰位、峰高、峰位差、峰高比进行比较分析 ,发现有多个变量可以显示两类光谱的差异 ,选择峰高比参数建立了Logistic预测方程为光谱的应用进行了探索。结果表明可以借助数学方法对组织光谱进行数据转换和分析 ,为了研究大量的组织光谱提供思路。     

微波输入功率引起a-C∶F薄膜交联结构的增强

使用C2H2和CHF3的混合气体,在改变微波功率的条件下,利用微波电子回旋共振等离子体增强化学气相沉积方法制备了氟化非晶碳薄膜(aC∶F).薄膜的傅里叶变换红外光谱分析结果表明:薄膜中的CC与C—F键含量的比值随功率的增加而相应地增大;借助于紫外可见光谱分析发现,薄膜的光学带隙随功率的增大而减小.由此推断微波输入功率的提高有助于增强薄膜的交联结构.aC∶F薄膜的交流电导与x射线光电子能谱进一步证实了这种增强效应 关键词： 氟化非晶碳薄膜 傅里叶变换红外光谱 x射线光电子能谱     

滇丹参与丹参的傅里叶变换红外光谱对比研究

本文采用傅里叶变换红外光谱方法(FTIR)对中药材滇丹参和丹参及中成药复方丹参片进行了对比研究,比较了它们的红外光谱的异同.研究表明,滇丹参和丹参的红外光谱的部分吸收峰各峰之间构成相互对应关系,表明滇丹参与丹参所含的主要化学成分相似;滇丹参与丹参的红外光谱在1263、1062、668～541 cm-1三处峰形存在明显的...     

中药重楼及其伪品开口箭的FTIR分析与鉴别

本文采用傅里叶变换红外光谱方法(FTIR)对中药材重楼及其伪品开口箭的红外光谱进行了测试及对比分析。研究表明,重楼和开口箭各自有其独特的红外光谱特征,二者各自所包含的红外吸收峰的峰位明显不同,二者的红外光谱的峰形整体上有非常明显的区别,特别是在1650cm-1处及1405～1258cm-1范围这两个地方二者的峰形有非常明显的区别。采用傅里叶变换红外光谱方法可对重楼及其伪品开口箭加以鉴别和区分。     

Deposition of hexagonal boron nitride thin films on silver nanoparticle substrates and surface enhanced infrared absorption

Silver nanoparticle thin films with different average particle diameters are grown on silicon substrates. Boron nitride thin films are then deposited on the silver nanoparticle interlayers by radio frequency （RF） magnetron sputtering. The boron nitride thin films are characterized by Fourier transform infrared spectra. The average particle diameters of silver nanoparticle thin films are 126.6, 78.4, and 178.8 nm. The results show that the sizes of the silver nanoparticles have effects on the intensities of infrared spectra of boron nitride thin films. An enhanced infrared absorption is detected for boron nitride thin film grown on silver nanoparticle thin film. This result is helpful to study the growth mechanism of boron nitride thin film.     

工作压强对硅掺杂辉光放电聚合物结构和性能的影响

采用辉光放电聚合技术,在不同工作压强条件下制备了掺硅的辉光放电聚合物(Si-GDP)薄膜.并采用傅里叶变换红外吸收光谱和X射线光电子能谱(XPS)对Si-GDP薄膜进行了表征,分析了压强变化对其内部结构及成分的影响.利用紫外—可见光谱对Si-GDP薄膜的光学带隙进行了分析.结果表明:Si-GDP薄膜中Si元素主要以Si—C,Si—H,Si—O,Si—CH₃的键合形式存在;随着工作压强的增大,薄膜中Si—C键相对含量先减小后增加;从Si-GDP薄膜的XPS分析可以发现,C—C与C C含 关键词： 硅掺杂辉光放电聚合物薄膜 工作压强 傅里叶变换红外吸收光谱 X射线光电子能谱     

七种牛肝菌的红外光谱鉴别

运用傅里叶变换红外光谱、二维相关谱及主成分分析对7种同属牛肝菌进行分析鉴别。结果显示：7种牛肝菌的原始光谱总体特征相似,主要由蛋白质、多糖等的吸收峰组成,但在吸收峰强度、位置仍存在差异。对样品进行二维相关红外光谱分析,在二维相关红外光谱1 680～1 300 cm-1范围内,茶褐牛肝菌和双色牛肝菌出现了6个明显的自动峰;小美牛肝菌出现了5个明显的自动峰;灰褐牛肝菌和美柄牛肝菌出现4个明显自动峰;美味牛肝菌和铜色牛肝菌自动峰相对较少,只出现了3个明显的自动峰;而且自动峰和交叉峰的强度、位置也存在较大差异。同样在二维相关红外光谱1 150～920 cm-1范围内,不同牛肝菌的同步谱中自动峰和交叉峰的数量、强度和位置也不同。对光谱1 800～800 cm-1范围内的二阶导数进行主成分分析,所有样品均区分开,其分类正确率达100%。结果表明,傅里叶变换红外光谱结合二维相关红外光谱或者主成分分析可以有效地区分茶褐牛肝菌、小美牛肝菌、双色牛肝菌、灰褐牛肝菌、美柄牛肝菌、美味牛肝菌和铜色牛肝菌。该方法对于分类鉴别蘑菇是一种快速、准确、有效的方法。     

Interfacial bonding characteristic of nanoclay/polymer composites

Using a small amount of nanoclay (montmorillonite (MMT)) can significantly enhance the thermal and mechanical properties of polymer-based composites. Therefore, an in depth understanding of the bonding characteristic between the nanoclay and its surrounding matrix is essential. In this study, Fourier Transform Infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) were conducted to analyze the chemical composition between epoxy matrix and nanocomposite. These experiments revealed that a chemical bonding at an interface between the matrix and nanoclay of the composites did exist. Thus, such bonding can enhance the mechanical and thermal properties of resultant polymer composites as reported in many literatures.     

Surface analysis for LiBq4 growing on ITO and CuPc film using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS)

We have investigated the morphology and surface electron states of LiBq₄ deposited on ITO and CuPc/ITO, using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The AFM observations indicate that LiBq₄ can form a much more uniform film on CuPc than that on ITO. Furthermore, X-ray photoelectron spectroscopy (XPS) is utilized to further demonstrate the AFM results. From the analysis of XPS, we found that LiBq₄ molecules have poor thermal stability, they are seriously oxidized during depositing; but when a CuPc layer is inserted between LiBq₄ and ITO film, the oxidation and surface contamination of LiBq₄ are significantly reduced. It is then concluded that the introduction of a CuPc buffer layer under the LiBq₄ film can improve the film quality of LiBq₄.The XPS results also testified the fact that no coordination bonds between N atoms and B atoms are formed in LiBq₄ molecules, which make LiBq₄ to be potential blue organic light-emitting material.     

Ultra-thin Si overlayers on the TiO2 (1 1 0)-(1 × 2) surface: Growth mode and electronic properties

The growth of thin subnanometric silicon films on TiO₂ (1 1 0)-(1 × 2) reconstructed surfaces at room temperature (RT) has been studied in situ by X-ray and ultra-violet photoelectron spectroscopies (XPS and UPS), Auger electron and electron-energy-loss spectroscopies (AES and ELS), quantitative low energy electron diffraction (LEED-IV), and scanning tunneling microscopy (STM). For Si coverage up to one monolayer, a heterogeneous layer is formed. Its composition consists of a mixture of different suboxides SiO_x (1 < x ? 2) on top of a further reduced TiO₂ surface. Upon Si coverage, the characteristic (1 × 2) LEED pattern from the substrate is completely attenuated, indicating absence of long-range order. Annealing the SiO_x overlayer results in the formation of suboxides with different stoichiometry. The LEED pattern recovers the characteristic TiO₂ (1 1 0)-(1 × 2) diagram. LEED I-V curves from both, substrate and overlayer, indicate the formation of nanometric sized SiO_x clusters.     

Thiolated poly(ε-caprolactone) macroligand with vacant coordination sites on gold substrate: Synthesis and surface characterization

Surface-confined telechelic poly(ε-caprolactone) macroligand with two distinct functional groups per polymeric chain has been synthesized and characterized. The molecular microstructure of the macroligand with regard to the properties of the end-capped functionalities and with those on surface substrate has been studied by solution and surface analytical methods (i.e., X-ray photoelectron spectroscopy (XPS), grazing angle reflectance-Fourier transform IR spectroscopy (GA-FTIR), water contact angle measurements, and atomic force microscopy (AFM)) to elucidate the structure and properties of such multifunctional polymer on gold (1 1 1) substrate.     

傅里叶变换红外光谱与拉曼光谱分析碳青霉烯药物亚胺培南的结构特征

本文采用傅里叶变换红外光谱和激光拉曼光谱对碳青霉烯药物亚胺培南进行光谱检测,并对其的分子振动光谱与结构特征进行分析和探讨,分析了亚胺培南在固相状态下的结构形式,从而为药物合成及质量控制提供了重要的参考价值。     

Interfacial reaction of silver ultra-thin film deposited on interpenetrating polymer network substrate by liquor-phase reduction

The interfacial reaction, metal transformations, and nonmetal bond types of silver ultra-thin film deposited on polyurethane (PU) based interpenetrating polymer networks (IPN) substrate by the liquor-phase reduction at room temperatures were studied by atomic force microscope (AFM), X-ray photoelectron spectroscopy (XPS) and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). The IPN substrate was prepared by dip-pulling precursors onto a silicon wafer or a glass plate, followed by solidification at room temperature. The interpenetrate structures of IPN with two crosslinked networks restricted the aggregation of silver during the reduction and deposition. The devised -OH terminal group in PU simplified the determination of reactive site in IPN and reinforced the adhesion between IPN and silver through interfacial reaction. The XPS results, which matched well with the ATR-FTIR results, verified the chemical reactive site of PU in IPN with silver in the oxide state.     

Synthesis and characterization of Cr doped CdS nanoparticles stabilized with polyvinylpyrrolidone

Undoped and Cr (2 and 4 at.%) doped CdS nanoparticles were synthesized in aqueous solution by simple chemical co-precipitation method using polyvinylpyrrolidone (PVP) as stabilizer. The prepared nanoparticles were examined using X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDAX), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (DRS) and Fourier transform infrared spectroscopy (FTIR). XRD pattern of the nanoparticles showed cubic zincblende phase with the particle size of the order of 3-4 nm, which was in good agreement with the results obtained from TEM studies. The EDAX analysis confirmed that Cd, Cr and S elements were present in the samples and the variations between the target and actual compositions were microscopic. UV-vis DRS spectra of the samples exhibited decrease in the band gap which further attests the incorporation of Cr into CdS nanoparticles. FTIR studies revealed that the undoped as well as Cr doped CdS nanoparticles were capped by polyvinylpyrrolidone.     

Physical-morphological and chemical changes leading to an increase in adhesion between plasma treated polyester fibres and a rubber matrix

The effects of plasma treatment, used to increase adhesion strength between poly(ethylene terephtalate) (PET) fibres and a rubber matrix, were investigated and compared. Morphological changes as a result of atmospheric plasma treatment were observed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Wettability analysis using a surface energy evaluation system (SEE system) suggested that the plasma treated fibre was more wetting towards a polar liquid. When treated, these fibres showed a new lamellar crystallization, as shown by a new melting peak using differential scanning calorimetry (DSC). X-ray photoelectron spectroscopy (XPS) has been used to study the chemical effect of inert (argon), active and reactive (nitrogen and oxygen) microwave-plasma treatments of a PET surface. Reactive oxygen plasma treatment by a de-convolution method shows new chemical species that drastically alter the chemical reactivity of the PET surface. These studies have also shown that the surface population of chemical species formed after microwave-plasma treatment is dependent on the plasma gas. All these changes cause better adhesion strength of the PET fibres to the rubber matrix.