H2O2–Ng dynamics predictions using an accurate potential energy surface

ABSTRACT

Based on ab initio calculations, our research group has built an analytical ground-state potential energy surface (PES) for hydrogen peroxide– noble gas (Ng) interactions, such as H₂O₂–He, H₂O₂–Ne, H₂O₂–Ar, H₂O₂–Kr, and H₂O₂–Xe complexes. From this PES, it was verified that the Ng presence does not affect the equilibrium values of the H₂O₂ dihedral angles. This happens because the H₂O₂ intramolecular barriers have much higher energies than the atom–bond interaction within these complexes. From this point of view, it is indeed reasonable to consider the H₂O₂ system as a rigid rotor, frozen at its equilibrium configuration. We present in this work the torsional motion for the H₂O₂ isolated system, the vibration–rotation energy levels and spectroscopic constants for hydrogen peroxide–noble gas by using the aforementioned PES. The predicted H₂O₂ torsional motions are in good agreement with both theoretical and experimental results available in the literature. Regarding H₂O₂–Ng ro-vibrational energies and spectroscopic constants, it is the first time that these calculations are presented in the literature. The current theoretical predictions are expected to be useful in the future experimental investigations.     

A relaxation times coupling method to construct acoustic relaxation calibration for two-frequency measuring gas compositions

In our previous work (Hu et al., 2014), a method has been proposed to detect gas compositions by locating the acoustic spectral peaks, which can be detected only by two-frequency acoustic measurements in practice. However, as a ‘Detection Calibration’, the effective relaxation area (ERA) constructed by existing theoretical model cannot match the two-frequency measurements when there are more than one strong relaxational components in gas mixtures. This paper proposes a method to construct the ERA by coupling the decoupled single relaxation times together to a whole relaxation time. For gas mixtures with only one single relaxation process, the predicted ERA results match with the experimental data better than those predicted by the existing model. Moreover, for gas mixtures in which more than one relaxation process are significant, the ERA results predicted by the proposed method also match with the detection results of two-frequency measurements better than the existing model. This relaxation time coupling based ERA constructing method is validated by the application in low-quality natural gas detection.     

Half-Width Integral Method for Gas Concentration Measuring in Tunable Diode Laser Absorption Spectroscopy

ABSTRACT

We analyze the influence of random errors and absorption shape fitting errors on gas concentration measurement in tunable diode laser absorption spectroscopy. We then propose a new data processing method according to the characteristic of random errors and fitting absorption shape. This method only uses the integral value within the half width at half maximum of the fitting absorption shape to determine the gas concentration in actual measurements. Meanwhile, the O₂ transition at 13,150.197 cm^?1 is selected to measure the O₂ concentration using this method. Compared with the traditional method, the method established in this paper can accurately measure O₂ concentration.     

Microplasma Technology and Its Applications in Analytical Chemistry

Abstract

This review article describes some existing microplasma sources and their applications in analytical chemistry. These microplasmas mainly include direct current glow discharge (DC), microhollow-cathode discharge (MHCD) or microstructure electrode (MSE), dielectric barrier discharge (DBD), capacitively coupled microplasmas (CCμPs), miniature inductively coupled plasmas (mICPs), and microwave-induced plasmas (MIPs). The historical development and recent advances in these microplasma techniques are presented. Fundamental properties of the microplasmas, the unique features of the reduced size and volume, as well as the advantageous device structures for chemical analysis are discussed in detail, with the emphasis toward detection of gaseous samples. The analytical figures of merit obtained using these microplasmas as molecular/elemental-selective detectors for emission spectrometry and as ionization sources for mass spectrometry are also given in this review article.     

Pion mass dependence of the nucleon mass in the chiral quark soliton model

The dependence of the nucleon mass on the mass of the pion is studied in the framework of the chiral quark-soliton model. A remarkable agreement is observed with lattice data from recent full dynamical simulations. The possibility and limitations to use the results from the chiral quark soliton model as a guideline for the chiral extrapolation of lattice data are discussed.     

一种用于LSPR传感器的准正方型银纳米颗粒阵列制备

首先控制聚苯乙烯纳米球(PS球)乳液在基片上的干燥温度,采用自组装方法,使用单一粒径的PS球制备出单层的PS球亚稳态正方排列结构模板。然后,在模板上通过磁控溅射法沉积一层银膜。利用纳米球光刻技术,去掉PS球模板得到二维正方点阵排列的准正方形银纳米颗粒阵列结构。     

含气量测量仪的研制

利用压强差与液体中含气量间的关系,制作出液体中含气量的测量装置。     

An application of the dust grain charging model to determination of secondary electron spectra

Dust grains – objects of different shapes with a size distribution from micro to nanometers – are generally considered as a part of many space as well as laboratory plasmas. Among various dust charging processes, electron-induced secondary emission plays an important role in plasmas containing a noteworthy portion of high-energy electrons. Since a part of secondary electrons has not the energy high enough to overcome the surface potential barrier, the resulting grain charge is determined not only by the secondary emission yield (related to the grain material and size) but also by the secondary electron spectrum. We have developed a model of secondary electron emission from small dust grains. In the present contribution, we discuss the profile of a secondary emission yield that can be received from the model and the measured equilibrium grain charge, both as functions of an incident electron beam energy. A comparison of these quantities leads to an estimation of secondary electron spectra. We have found that: (1) the energy spectrum of secondary electrons does not change with the energy of primary electrons and (2) the energy spectrum depends on the target material being harder for gold and silver than for glass grains.