Spatially resolved infrared spectroscopy: a novel technique for in situ study of spatial surface coverage during CO oxidation on supported catalysts

A spatially resolved infrared (IR) imaging technique to monitor the linear adsorbed CO coverage on supported catalyst surface combining an IR bandpass filter and an IR thermography camera has been developed. Images acquired during the CO adsorption/desorption and ignition indicate that the technique provides an excellent method to image the change of surface coverage with a spatial resolution. It is expected that the combination of infrared thermography with spatially resolved imaging of surface coverage will provide a deeper insight in the dynamics of spatio-temporal patterns on heterogeneous catalysts.     

10.6μm线性声光调制器研究

本文讨论的１０．６μｍ线性声光调制器，采用Ｇｅ单晶作为声光介质，工作中心频率为８０ＭＨｚ，３ｄｂ带宽为７ＭＨｚ。在驱动射频源输出功率８Ｗ的条件下，得到器件衍射效率峰值达３６％，该器件已作为激光束强度调制器件应用于视频／红外动态图象转换装置中。     

Mutual information based registration of multimodal stereo videos for person tracking

Research presented in this paper deals with the systematic examination, development, and evaluation of a novel multimodal registration approach that can perform accurately and robustly for relatively close range surveillance applications. An analysis of multimodal image registration gives insight into the limitations of assumptions made in current approaches and motivates the methodology of the developed algorithm. Using calibrated stereo imagery, we employ maximization of mutual information in sliding correspondence windows that inform a disparity voting algorithm to demonstrate successful registration of objects in color and thermal imagery. Extensive evaluation of scenes with multiple objects at different depths and levels of occlusion shows high rates of successful registration. Ground truth experiments demonstrate the utility of the disparity voting techniques for multimodal registration by yielding qualitative and quantitative results that outperform approaches that do not consider occlusions. A basic framework for multimodal stereo tracking is investigated and promising experimental studies show the viability of using registration disparity estimates as a tracking feature.     

金属表面柴油机油沉积物的反射红外光谱法研究

利用镜反射红外光谱法研究了ＣＣ级柴油机油中添加剂对成漆板板面漆膜组成的影响：考察了成漆板漆膜组成与Ｃａｔ．１Ｈ２活塞环台漆膜组成的相关性。试验结果对柴油机油的研制和应用有一定指导作用。     

红外热象仪在电力系统中的应用

本文主要阐述使用红外热象仪检测运行中的电力设备所发现的问题。文中通过若干实例介绍了用红外热象仪检测带电运行的发电机、电容器及连接头，并查出带有严重缺陷的部位，从而避免事故发生。     

In Situ FTIR Study of the Formation of an Organosilane Layer at the Silica/Solution Interface

An FTIR experiment especially designed to study the growth of an organosilane layer at the interface between a solution and a flat silica surface is presented. High sensitivity is achieved by using the attenuated total reflection (ATR) technique in a liquid flow cell. The ATR crystal, either silicon or germanium, is covered with a very thin silica layer. Chemical reactions of a mono-and a di-hydrolyzable silane with the silica substrate have been investigated. The grafting of a submonolayer of the first reagent has been monitored by following the C-H and SiO-H vibrations. The density of grafted molecules has been estimated and information on the nature of the chemical bonding has been achieved. Evidence for the chain-polymerization of the dihydrolyzable silane at the substrate/solution interface has been inferred from the appearance of a Si-O-Si absorption band.     

An infrared spectroscopic study of the mechanism of chloromethane conversion to higher hydrocarbons on HZSM5 catalyst

Investigation of the reaction mechanism of chloromethane on ZSM5 is a new topic. In this work an in situ FTIR technique was employed to study the conversion processes of chloromethane, the active sites on HZSM5, and the desorption state of surface species. The catalytic conversion of chloromethane to higher hydrocarbons was also studied. It is demonstrated that chloromethane can be reversibly adsorbed on acidic sites of HZSM5 at room temperature. At 100°C chloromethane is irreversibly and dissociatively adsorbed on the strong acidic sites of HZSM5, on which surface methoxyl is formed as proved by infrared characteristic C-H stretchings of-CH₃ at 2960 and 2870 cm^–1. Alkoxyls are produced and adsorbed on the catalyst surface as characterized by the infrared absorption bands of -CH₂-groups at 1460 and 2930 cm^–1. At 100°C the adsorbed methoxyl and alkoxyls are the main surface species, and a small amount of aromatics might exist as detected by a characteristic absorption band at 1510 cm^–1. Between 100 and 200°C the adsorbed surface methoxyl and alkoxyls are converted to aromatics, and the occupied OH groups partially appear. At temperature higher than 300°C the adsorbed aromatics are thermally desorbed into the gas phase. Aromatics and alkanes are the main products in catalytic conversion. These results reveal that the formation of aromatics from methoxyl and alkoxyls is easier than the desorption of aromatics from HZSM5 catalyst. An alkoxyl mechanism is proposed for the conversion of chloromethane on HZSM5 based upon the experimental results and the three assumptions: (a) The primary C-C bond is formed from surface methoxyl groups via the methoxyl group polarization and C-H bond weakening, (b) The adsorbed alkoxyls are converted to aromatics via hydrogen transfer and bond rearrangement similar to the conventional carbenium ion mechanism for the aromatization of olefins and alkanes on HZSM5. The hydrogen atoms from the aromatization stimulate the desorption of alkoxyls to alkanes. (c) At temperature higher than 300°C surface reactions and desorption of adsorbed species take place simultaneously, determining the product distribution in the catalytic conversion.     

Status and application of HgCdTe device modeling

In this article, device modeling refers to numerical simulation of semiconductor device physics to predict electrical behavior. The silicon integrated circuit industry provides the example for the use of technology computer-aided design to simulate wafer fabrication processes, and the electrical performance of devices and circuits. This paper first reviews semiconductor device modeling in general, then as applied in work supporting the development and analysis of HgCdTe infrared detectors. Example applications of one- and two-dimensional device modeling are simulation of a bias-selectable, integrated two-color detector, and two-dimensional effects on the spectral response of a HgCdTe detector with composition grading.     

浅谈红外测温在发现运行电力设备缺陷方面的应用

红外检测技术水平日臻成熟,在电力系统中作为有效、便捷的缺陷检测手段越来越受到各级管理部门的重视,本文通过工作中红外测温发现的一个缺陷实例,阐述了用红外测温发现缺陷时应注意的几个问题。     

The intervalley X6→Γ6, L6 scattering time in GaAs measured by ultrafast pump-probe infrared absorption spectroscopy

A direct measurement of the dynamics of electrons in the X₆ valley for a GaAs crystal by time-resolved absorption spectroscopy is reported for the first time. IR picosecond probe pulses were used to monitor the growth and decay of the population in the X₆ valley subsequent to excitation by a 527 nm pump pulse. The intervalley X₆→Γ₆, L₆ scattering time t_x of 0.70 ± 0.50 ps is determined and the crossection for the X₆→X₇ transition is estimated to be 1.8 × 10⁻¹⁶ cm².