Vibrational spectra,normal coordinate analyses,and molecular configurations of crystalline propionic acid

Temperature dependence of the IR spectra of crystalline propionic acid were examined in the temperature range 242–50 K. The intensities of most absorption bands increased on lowering the temperature, but some bands diminished until they disappeared at temperatures lower than about 120 K. Normal coordinate analyses indicate that the former bands are due to the stable cis dimer and the latter due to the less stable trans dimer which would be produced from the cis dimer by simultaneous proton transfer along two hydrogen bonds.     

LED大屏幕视频图象显示亮度校正的一种方法

在大屏幕视频显示的研究中,通常将侧重点放在显示驱动电路的优化上。本文从人眼的主观视觉理论出发,讨论了大屏幕视频图象显示与主观视觉之间的关系。并提出了一种很好的校正理论。经过实验检验,它能在图象列信息相同时,不管背景图象如何,均能使显示屏保持相同的亮度,使显示的视频图象的质量得以提高.     

Caractéristique directionnelle calculée et mesurée d'une sonde électrochimiqueCalculated and measured directional characteristic of an electrochemical probe

The present paper demonstrates how the directional characteristics of an actual three-segment electrodiffusional sensor can be calculated from the probe image. It was shown that utilization of ‘ideal’ directional characteristics lead to an important (up to 15^°) error in flow angle determination. The directional characteristics calculated from the probe image improve significantly (up to 50%) the accuracy of the flow angle measurements. To cite this article: F. Barbeu et al., C. R. Mecanique 330 (2002) 433–436.     

Une technique de lissage de données basée sur la théorie de la régularisationA filter technique based on regularization theory

A simple filter technique based on the regularization theory is presented. We consider the problem as an optimization one. The regularization theory gives us a suitable theoretical framework to define a functional to minimize. We make a numerical comparation between this method and a classical Fourier technique. To cite this article: J.-M. Fullana, C. R. Mecanique 330 (2002) 647–652.     

环戊烯分子内价轨道1a′的电子动量谱学研究

报道了环戊烯（C₅H₈）分子1a′轨道的电子动量谱，并且给出了价 轨道的电离能谱信息 .实验在非共面对称几何条件下用能量多道型电子动量谱仪完成，入射电子的能量为1200 eV 加结合能.通过Hartree-Fock 和密度泛函方法计算得到了C₅H₈分子 1a′轨道的动量谱. 对1a′轨道的电子动量谱的实验值和理论计算进行了比较，得到了该轨道的极强度（pole s trength）的信息.     

Bayesian fusion of GNSS,ITS-G5 and IR–UWB data for robust cooperative vehicular localization

In the automotive domain, Cooperative Localization (CLoc) is a new promising paradigm that aims at outperforming conventional Global Navigation Satellite Systems (GNSS) in terms of positioning accuracy, robustness, and service continuity, by relying on Vehicle-to-Vehicle (V2V) communications and hybrid data fusion. However, the growing number and the variety of the sensors aboard vehicles raise unprecedented challenges, especially in the context of distributed fusion approaches. This paper thus compares parametric and nonparametric Bayesian data fusion engines (e.g., based on cooperative variants of the Extended Kalman Filter (EKF) and Particle Filter (PF), respectively), while validating a CLoc scheme suitable to Vehicular Ad Hoc Networks (VANETs). More particularly, absolute position information from both onboard GNSS receiver and ITS-G5 V2V messages, as well as relative distance measurements based on the Impulse Radio–Ultra-Wideband (IR–UWB) technology, are combined into a single location solution that is hopefully more robust and more accurate than that of standalone GNSS. First, we investigate V2V ranging accuracy on a highway under real mobility conditions. In the same environment, we then provide offline validations of CLoc positioning, confirming significant performance gains through cooperation over conventional GNSS, even in case of poor initialization. In this specific context, the PF solution is thus shown to yield even better accuracy in comparison with EKF, thanks to its fine robustness against faced non-linear dynamics and non-Gaussian noise processes. Finally, we illustrate the resilience of the proposed solution under temporary GNSS denial.     

关于对流方程的离散化问题

本文讨论了用矩形网格离散化对流方程的一般方法,若格式含有N 个网点,则其最高阶格式为N- 2阶,同时构造了一些新的高精度差分格式     

Preliminary selection of clay minerals for the removal of pharmaceuticals,bisphenol A and triclosan in acidic and neutral aqueous solutions

Pharmaceuticals, personal care products and endocrine disruptors demonstrate huge potential to cause adverse ecological health effects at very low concentration in aquatic environment. There is a need to improve current purification technologies used in sewage and drinking-water treatment plants. This article aims at providing new insights into the recent development of natural and modified clay-based sorbents for the removal of aqueous contaminants such as pharmaceuticals and personal care products. The removal of six widely used pharmaceuticals: ibuprofen, diclofenac, ketoprofen, carbamazepine, as well as endocrine disrupting chemicals – bisphenol A and a bactericidal agent, triclosan – was examined by sorption onto eight adsorbents. Sorption was performed using natural and modified clay minerals – montmorillonite (Mt), vermiculite (VER), bentonite (B), kaolinite (K), commercial acid activated montmorillonites K10 and K30, and two carbonaceous-mineral nanocomposites, MtG5%T, BAlG3%C. This study showed that among the tested natural clays, vermiculite is the most promising sorbent for the removal of pharmaceuticals in purification processes. Among the modified clay minerals, the best results were achieved for carbonaceous bentonite and two acid activated montmorillonites K10 and K30. However, the removal of acidic pharmaceuticals on montomorillonite K10 and carbonaceous bentonite was strongly dependent on the pH value. In the case of vermiculite and acid-modified montmorillonite K30, the sorption of the selected compounds was not significantly affected by pH, which is crucial in wastewater treatment. The sorption constant divided by the specific surface area (K_d/A) is proposed to assess whether the surface area or chemical properties of the materials control the sorption process. K_d/A values were relatively high in the case of vermiculite, so it should be noticed that individual and specific surface properties of vermiculite were of crucial importance for sorption.