Measurements of collisional broadening coefficients by infrared polarization spectroscopy

We present measurements of collisional broadening coefficients, obtained at atmospheric pressure, by polarization spectroscopy. Using tunable single mode laser radiation at approximately 2 microm, high-resolution infrared polarization spectra were recorded for CO2-Ar and CO2-He binary mixtures. The recorded polarization spectra were fitted with a Lorentzian cubed function form to obtain the broadening coefficients. The full-width at half-maxima (FWHM) collisional broadening rates of CO2 by Ar and He, for the R14 (12 degrees1<--00 degrees0) line, have been determined to be 0.161+/-0.018 cm-1 atm-1 and 0.1823+/-0.0032 cm-1 atm-1, respectively.     

Colloidal gold filtrates as metal substrates for surface-enhanced infrared absorption spectroscopy.

A new method for obtaining surface-enhanced infrared absorption (SEIRA) spectra of antibodies and antibody/antigen complexes has been developed. Antibodies attached to colloidal gold particles and then collected by filtration onto porous polyethylene membranes show enhanced spectral bands at 1080 and 990 cm-1 regardless of the antibody specificity. Attachment of a model antigen, glucose oxidase, to its specific antibody/colloid complex prior to collection produces enhanced bands at 1540, 1395, and 1250 cm-1. Similarly, when the antigen Salmonella is attached to its specific antibody/colloid complex prior to collection, a new enhanced band is observed at 1015 cm-1. Similarities and differences of the SEIRA spectra obtained on gold colloid are compared to previous work on gold films.     

Mid-infrared quantum cascade lasers for flow injection analysis

A Fabry-Perot quantum cascade laser (QCL) was used as a powerful light source for mid infrared (MIR) detection in flow injection analysis. The QCL lased at several wavelengths close to each other within a few wavenumbers (990-1010 cm-1), hence fitting well to the broad absorption bands of molecules in liquid phase. As compared with that of a state-of-the-art Fourier transform spectrometer, the signal-to-noise ratio could be improved by a factor of 50. Additionally, by using a QCL as the light source, optical path lengths of more than 100 microns could be used even in aqueous matrixes which reduced the danger of cell clogging. In the example shown here phosphate was determined in Diet Coke samples. The flow injection system used allowed the measurement of the sample at two pH values (5 and 13) at which the analyte was present as H2PO4- and PO4(3-), respectively. As the analytical readout the difference in IR absorption of H2PO4- and PO4(3-) at the laser wavelengths was taken. The FIA-QCL measurements were corroborated by ion chromatography which was used as a reference method.     

优化处理祖母绿的鉴定方法

对天然及优化处理祖母绿的鉴定方法进行研究和分析。通过传统的显微放大方法观察祖母绿的充填及染色处理痕迹,证明了该方法是鉴别处理祖母绿的一个首选和重要的手段;进一步采用DiamondViewTM对这些样品用进行观察,发现充填裂隙主要呈浅黄绿色荧光,同时可以确定一些宝石显微镜下无法辨别的裂隙,因而可以作为进一步的验证手段。最后通过傅里叶变换红外光谱仪检测有无2 870 cm-1、2 925 cm-1、2 964 cm-1、3 034 cm-1、3 053 cm-1充填胶特征吸收峰以及激光拉曼光谱仪检测有无548 cm-1铬特征峰和1 602 cm-1、1 180 cm-1、1 107 cm-1、817 cm-1、633 cm-1充填胶特征峰来综合判定祖母绿是否经染色或充填胶处理。确立了快速、有效、准确鉴别处理祖母绿的流程和方法,此方法的确立对此类宝石样品的鉴定有着重要的指导意义。     

用傅立叶变换红外光谱法检测气体中微量乙硼烷

利用配备长光程气体池的傅立叶变换红外光谱仪对气体中微量乙硼烷进行了定量分析。在恒定实验条件下进样,分辨率为4 cm~(-1),扫描8次,可以得到理想的分析结果。定量分析结果表明,该方法重复性良好(相对标准偏差0.5%),在0~100×10~(-6)摩尔分数范围内线性良好(R~2=0.9996),扩展不确定度小(4%),可用于气体中微量乙硼烷的定量分析。     

利用粘度法和二维红外相关光谱法研究胶原/羟丙甲基纤维素共混物的相互作用

采用粘度法和二维红外相关光谱法对胶原/羟丙甲基纤维素共混体系的相容性及相互作用进行了研究。粘度法测定结果表明,羟丙甲基纤维素含量<30%时共混体系相容,超过50%则不相容。二维红外相关光谱法的分析结果表明,当羟丙甲基纤维素含量<30%时,归属于羟丙甲基纤维素的C—O(H)伸缩振动峰1061cm-1与归属于胶原酰胺带的CO对称伸缩振动峰1660cm-1、N—H摇摆振动峰1553cm-1和N—H面内变形振动峰1238cm-1之间存在同步负交叉峰,表明胶原和羟丙甲基纤维素之间存在氢键作用;而当羟丙甲基纤维素含量>30%时,同步图中负交叉峰强度减小的同时同步峰1061cm-1的强度明显变大,表明此时羟丙甲基纤维素与胶原之间的氢键作用变弱,羟丙甲基纤维素更倾向于在自身分子之间形成氢键。     

Generation of tunable, narrow-band mid-infrared radiation through a 532-nm-pumped KTP optical parametric amplifier

We report generation of broadly tunable (2.5-4 μm), narrow-band (0.04-0.35 cm-1) pulsed infrared radiation through a nanosecond optical parametric amplifier based on potassium titanyl phosphate (KTP) pumped by the second harmonic of a 10-Hz Nd:YAG laser. Input radiation at signal wavelengths of 615-662 nm was derived from a pulsed tunable dye laser system. Advantages of this device are simplicity, the broad range of infrared wavelengths to which a single dye in the dye laser provides access, and conversion efficiencies >10% at modest levels (<150 μJ) of input radiation.     

Electrical conductivity and infra red of CaTiO3 doped with CuO

The electrical conductivity of pure CaTiO3 and that containing 0.5～5.0 mole fraction CuO as dopant were measured in the temperature range 291～773 K. The conductivity values varied as a function of temperature and dopant concentration. The activation energy in the lower temperature range depended on the impurity content while in the high temperature range it indicated a value of energy gap width. The infrared absorption spectra in the range of 100～4000 cm-1revealed the presence of two main bands at 340 and 570 cm-1 which were assigned to TiO6 octahedral normal mode. Bands in the range of 106～270 cm-1 were due to the vibration of anion TiO-2. Some bands were observed at higher values due to the presence of lattice imperfections.There was a slight shift in band position with increasing dopant concentration which favors the formation of orthorhombic modification.     

微量特种气体的FT-IR定量分析

利用傅立叶变换红外光谱法对微量一氧化氮、二氧化氮、氧化亚氮、氨气、氯化氢、二氧化硫、二氯氢硅、三氯氢硅、四氯化硅等使用常规方法分析难度大、灵敏度不足、操作复杂的气体样品进行了定量分析.在恒定实验条件下进样,分辨率为4 cm-1,扫描8次,可以得到理想的分析结果.以氨气、一氧化氮和二氧化氮为例的定量分析结果表明,该方法重...     

采用二维红外技术研究交联对碱溶胶原结构的影响

以N-羟基琥珀酰亚胺己二酸酯(NHS-AA)为交联剂,交联改性碱溶胶原,采用二维红外相关光谱法研究了交联对胶原二级结构的影响。研究发现,交联未影响胶原红外特征吸收峰的位置,但1672、1554和1241cm-1归属于胶原酰胺I带的CO伸缩振动、酰胺Ⅱ带的C—N伸缩与N—H弯曲振动和Ⅲ带的N—H面内变形振动峰之间存在同步正交叉峰,表明随交联共价键的增加,胶原的链段构象发生了变化。在NHS-AA用量增加的过程中,胶原二级结构变化的顺序为:酰胺Ⅲ带>酰胺Ⅰ带>酰胺Ⅱ带>—CH3>—CH—。由此可见,二维红外相关分析法能提供由交联引起的胶原构象动态变化的微观信息,为进一步研究改性胶原结构与功能之间的关系提供实验依据。     

Microplate-compatible biamperometry array for parallel 48-channel amperometric or coulometric measurements

We report a new reusable electrochemical array for parallel biamperometric measurements that has been designed for use with standard microplates. The 48-channel array uses half of the available 96 wells and has 48 pairs of Pt wire electrodes. Applications to the quantitation of a variety of oxidizable species, including acetaminophen, ascorbic acid, hydroquinone, trolox, and uric acid, are demonstrated in assays that use potassium ferricyanide as an oxidant to produce a mixture of ferri- and ferrocyanide. Hydrogen peroxide quantitation is also demonstrated, based on an assay in which ferrocyanide is oxidized, again to produce a mixture of ferri- and ferrocyanide. Detection limits (signal-to-noise ratio (S/N) = 3) in these assays range from 1 (acetaminophen, R2 = 0.994) to 8 microM (ascorbic acid, R2 = 0.967), and linearity was observed to analyte concentrations of at least 100 microM. We also demonstrate the application of the biamperometric array to enzymatic assays, using the glucose oxidase reaction as an example; following a 20 min enzyme reaction time, a detection limit of 0.1 mM glucose was obtained. These results indicate that applications to other oxidase-based assays are feasible in this high-throughput format. The new electrochemical array employs standard, inexpensive microplates, and the biamperometric measurements are simple, precise, and rapid, requiring only 2 min for 48 parallel measurements.     

Visible intracavity laser spectroscopy with a step-scan Fourier-transform interferometer

A Fourier-transform spectrometer has been used in a step-scan mode to make time-resolved measurements of the evolving laser pulse in intracavity laser spectroscopy (ILS) experiments. Spectra of broadband dye laser pulses at approximately 615 nm were recorded at relatively high spectral (0.5-cm(-1)) and temporal (as high as 5-mus) resolution. In the absence of an absorber, the height of the pulse is shown to be proportional to t(g)(0.57) (where t(g) is the generation time) for generation times as high as 500 mus. The system was constructed for feasibility studies of future use at infrared and near-infrared wavelengths where conventional ILS that uses diode arrays would be either expensive or simply not possible. The CH(4) overtone transition at 619.68 nm was used to test the linearity and sensitivity of the system. Comparable performance to conventional ILS systems was demonstrated, as were the advantages of the present system for studies of laser and absorption dynamics.     

Infrarot‐Laserabsorptionsspektroskopie mit Quantenkaskadenlasern in der industriellen Anwendung

Infrared laser absorption spectroscopy with quantum cascade lasers in industrial application Spectroscopic methods for gas analysis and plasma diagnostics in the field of the mid infrared spectral range (MIR) were lacking in sufficient time resolution up to now, they were cumbersome and not robust enough or simply too expensive. Through quantum cascade lasers as radiation source the application of the MIR absorption spectroscopy in the industry can be revolutionized. Although the industrial use in the plasma process is still in its infancy, their enormous potential is already evident, as demonstrated by measurements on plasma etching systems in the semiconductor industry, which is impressively documented.     

插层型蔗糖/蛭石纳米复合材料的制备

以蔗糖和蛭石为原料,在超声辅助条件下采用溶液插层法制备插层型蔗糖/蛭石纳米复合材料。X射线衍射（XRD）、红外光谱（FTIR）分析表明,蔗糖/蛭石复合物样品的d001值为1.852nm;样品的红外谱图中出现甲基和亚甲基特征峰2761cm-1和2969cm-1。将蔗糖/蛭石复合物在氮气氛下碳化后,样品的XRD（d001=1.247nm）和红外光谱结果（甲基和亚甲基特征峰2761cm-1和2969cm-1消失）表明,碳/蛭石复合材料层间夹有碳,进一步证实得到插层型蔗糖/蛭石复合材料。同时,确定了优化插层反应工艺条件,超声功率为400W,物料配比为蛭石：蔗糖=1：2.5,超声水化时间为0.5h,超声反应温度为70℃,反应时间为2.5h,静置时间2h。     

Adhesive secretions of live mussels observed in situ by attenuated total reflection-infrared spectroscopy

The chemical species involved in the adhesion of blue mussels (Mytilus galloprovincialis) and greenshell mussels (Perna canaliculus) to surfaces has been investigated using in situ attenuated total reflection infrared (ATR-IR) spectroscopy. Mussel spat ranging in size from 0.5 to 25 mm were placed in a flow cell containing a ZnSe multiple internal reflection prism and supplied with temperature-controlled seawater. Distinctively different absorption spectra were obtained when the mussels were predominantly moving across the surface or forming permanent bonds. With limited movement, the absorption spectrum was characteristic of protein with peaks near 1647 cm-1 (amide I), 1543 cm-1 (amide II), and 1235 cm-1 (amide III). When the mussels were observed to be moving across the surface of the ATR-IR crystal there was a strong broad absorption maximum around 1200-900 cm-1 (carbohydrate polymers), presumably due to the secretion of a weakly acidic mucopolysaccharide. Distinct differences in the spectra obtained from the adhesive secretions of blue or greenshell mussels were not observed. The data presented is the first reported use of IR spectroscopy to obtain in situ, real-time, chemical data on the interactions between invertebrates and substrates immersed in sea water.     

Bi2O3对GeO2—SiO2基玻璃反常色散的影响

本文利用红外分光光度计,测定了ＧｅＯ２－ＳｉＯ２基玻璃系统中加入Ｂｉ２Ｏ３后在４０００～２５０ｃｍ＾－１波数范围内的反射率,通过对其红外折射率和消光系数的计算,研究了反常色散的变化规律,并进行了讨论。     

腔面镀膜分布反馈量子级联激光器

报道了后腔面蒸镀高反射率镀膜工艺及其对分布反馈量子级联激光器性能影响的研究结果.与没有腔面镀膜的器件相比,采用了腔面镀膜工艺的器件,室温下的阈值电流密度降低了20%,前腔面出光峰值功率提高了50%,斜率效率提高了44%.通过对比镀膜和未镀膜器件的闻值电流密度,估算出器件的波导损耗约为7.25cm-1.     

L-alpha-glycerophosphate and L-lactate electrodes based on the electrochemical "wiring" of oxidases.

The title electrodes were constructed by coimmobilizing the respective FAD oxidases on solid electrode surfaces with a poly(vinyl pyridine) polymer which was N-derivatized with bromoethylamine and Os(bpy)2Cl2. The redox-polymer-enzyme hydrogels were cross-linked on the electrode surface using poly(ethylene glycol) diglycidyl ether. As in the case of glucose oxidase, the redox polymer acts as an electron relaying "wire" transferring electrons directly from the enzymes' FADH2 centers to the electrode. This transfer competes with the natural process of reoxidation of FADH2 by molecular oxygen. The variation of the response of these electrodes with the atmosphere (N2 or air), pH, and substrate concentration was determined. The pH profile of the electrocatalytic current differs from that of the activity of the free enzymes, exhibiting a broader maximum, shifted to higher pH values. The observed sensitivities and linear ranges are respectively 2 x 10(-2) A M-1 cm-2 and 2.7 mM for L-alpha-glycerophosphate, and 0.3 A M-1 cm-2 and 0.2 mM for L-lactate that may be compared to 2 x 10(-2) A M-1 cm-2 and 10 mM for glucose. The 0-90% response time for all electrodes is 1 s or less.     

激光低温沉积金刚石膜

用ＸｅＣｌ紫外与ＣＯ２红外复合激光化学气相沉积方法，在３４０℃硅衬底上沉积成高纯金刚石膜。     

Real-time fourier transform-infrared analysis of carbon monoxide and nitric oxide in sidestream cigarette smoke

Fourier transform infrared (FT-IR) spectroscopy was compared directly to independent standard analytical techniques for the routine measurement of carbon monoxide (CO) and nitric oxide (NO) yields from cigarette sidestream smoke. The FT-IR instrument was configured in-line with a nondispersive infrared (NDIR) analyzer for CO analysis and a chemiluminescence (CL) analyzer for NO analysis to monitor the sidestream smoke from a single port of a linear smoking machine. A cold trap was inserted prior to the FT-IR to minimize the levels of vapor phase interferents, such as water. Univariate and multivariate regression analysis were evaluated for the prediction of cigarette yield from time-resolved spectral data at 1, 2, 4 and 8 cm-1 spectral resolution. Regressions were developed using three different spectral ranges including unique rotation-vibration lines, the R-branch, and the entire absorption band. As per standard methods, yields were calculated from the concentration traces generated during the smoke runs for five different cigarettes spanning the expected range of mainstream total particulate matter deliveries. The FT-IR traces for the smoke runs revealed improved temporal resolution yielding analytical information from smoke generated in between puffs. The performance between the validation methods and the FT-IR calibrations was statistically compared. In general, for the determination of CO, the FT-IR calibrations underestimated the yield measured by NDIR by less than 10%. For the NO measurement, the univariate FT-IR calibrations overestimated the NO yield measured by the CL analyzer, whereas the partial least squares (PLS) calibrations showed good agreement. PLS calibrations were developed for both analytes providing no significant difference when compared to the respective standard analytical techniques. Results for sidestream CO and NO yields for Kentucky reference cigarette 1R4F utilizing 8 cm-1 calibrations compared favorably to values reported elsewhere in the literature. Hence, calibration of the FT-IR system at 8 cm-1 spectral resolution clearly revealed the potential of this method, providing enhanced temporal resolution, simultaneous determination of several smoke components, and reduced complexity of the experimental setup in contrast to the standard techniques.