甲醇分子(CH3OH)光谱性质的理论计算

研究了气相甲醇分子(CH3OH)基态和激发态性质。在对不同方法基组所得计算结果和实验结果进行比较之后,选用MP2(full)/6-311++G(2d,2p)理论方法进行计算,得到甲醇分子(CH3OH)基态和三重激发态的几何结构、能量以及频率信息;频率计算显示基态和三重态都为稳定构型。从三重态的结构出发,解释了三重态势能面为排斥型势能面的合理性。计算了甲醇分子单重激发态的垂直激发能,比较不同方法不同基组计算的甲醇分子单重激发态的垂直激发能,发现用TDDFT 中的b3p86方法使用6-311++G**基组的计算值和实验值符合得最好。计算得到的甲醇分子在MP2(full)/6-311++G(2d,2p)的绝热电离能和垂直电离能分别为11.18eV和11.32eV;计算得到的绝热电子亲和势与垂直电子亲和势分别为0.888eV和0.893eV。计算结果对实验研究有指导意义。     

低电阻测量设计实验中电位差计指针不稳的解决方法

本文分析了J33Q型电位差计在实验中指针不稳的原因,并提出了解决的办法。     

替代法测量微安表内阻的不确定度分析

在测量微安表内阻的众多方法中,替代法是最简单的方法。本文全面分析了影响测量结果不确定度的因素,求出了实验测量的最佳条件,计算了普通仪器组合下测量结果的相对不确定度。     

微通道板真空体电阻与Ⅱ代倒象微光管匹配关系的研究

国内研制的20/30Ⅱ代倒象微光管经常出现微通道板真空体电阻偏高或偏低的问题,直接影响Ⅱ代倒象微光管荧光屏的亮度和目标分辨力,严重影响微光管的质量。经过对20/30Ⅱ代倒象微光管的研制和理论分析,证明英国马拉德公司对用于××1383Ⅱ代倒象微光管的H36微通道板技术条件中真空体电阻技术指标的规定也存在一定的问题。本文从目前国内外工艺水平和有关文献资料的分析出发,进行专题研究。本文中所推导的计算公式和对文献资料提供的技术数据的推导分析,同样适用于其他型号微通道板的真空体电阻与相应Ⅱ代、Ⅲ代微光管匹配关系的计算与研究。     

不同连接方案下垂直场线圈的性能研究

基于热-结构耦合分析了欧姆热和等离子体辐照引起的垂直场线圈的温度变化,对垂直场线圈在不同连接方式下的电气参数进行了研究,提出了一种优化的线圈连接方案.计算结果表明,该优化方案有助于改善垂直场线圈的响应性能,并提高其对等离子体的控制能力.     

An Adaptive Deblurring Vehicle Detection Method for High-Speed Moving Drones: Resistance to Shake

Vehicle detection is an essential part of an intelligent traffic system, which is an important research field in drone application. Because unmanned aerial vehicles (UAVs) are rarely configured with stable camera platforms, aerial images are easily blurred. There is a challenge for detectors to accurately locate vehicles in blurred images in the target detection process. To improve the detection performance of blurred images, an end-to-end adaptive vehicle detection algorithm (DCNet) for drones is proposed in this article. First, the clarity evaluation module is used to determine adaptively whether the input image is a blurred image using improved information entropy. An improved GAN called Drone-GAN is proposed to enhance the vehicle features of blurred images. Extensive experiments were performed, the results of which show that the proposed method can detect both blurred and clear images well in poor environments (complex illumination and occlusion). The detector proposed achieves larger gains compared with SOTA detectors. The proposed method can enhance the vehicle feature details in blurred images effectively and improve the detection accuracy of blurred aerial images, which shows good performance with regard to resistance to shake.     

Passivation of aluminium–n+ silicon contacts for solar cells by ultrathin Al2O3 and SiO2 dielectric layers

Ultra‐thin thermally grown SiO₂ and atomic‐layer‐deposited (ALD) Al₂O₃ films are trialled as passivating dielectrics for metal–insulator–semiconductor (MIS) type contacts on top of phosphorus diffused regions applicable to high efficiency silicon solar cells. An investigation of the optimum insulator thickness in terms of contact recombination factor J_{0_cont} and contact resistivity ρ_c is undertaken on 85 Ω/□ and 103 Ω/□ diffusions. An optimum ALD Al₂O₃ thickness of ～22 Å produces a J_{0_cont} of ～300 fAcm^–2 whilst maintaining a ρ_c lower than 1 mΩ cm² for the 103 Ω/□ diffusion. This has the potential to improve the open‐circuit voltage by a maximum 15 mV. The thermally grown SiO₂ fails to achieve equivalently low J_{0_cont} values but exhibits greater thermal stability, resulting in slight improvements in ρ_c when annealed for 10 minutes at 300 °C without significant changes in J_{0_cont}. The after‐anneal J_{0_cont} reaches ～600 fAcm^–2 with a ρ_c of ～2.5 mΩ cm² for the 85 Ω/□ diffusion amounting to a maximum gain in open‐circuit voltage of 6 mV. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Transmission and small angle scattering of 15 MeV electrons in silicon single crystals

Abstract

A novel technique for the study of structural damage incurred by single crystal silicon targets during ion implantation is described. The method is based upon copper-decoration of the vacancy rich damaged region, followed by radiochemical measurement of the resulting copper distribution. Utilizing neutron activation, sharply peaked radiocopper profiles are obtained, which are believed to represent the depth distributions of large, relatively immobile defects such as vacancy clusters, voids, or crystalline faults. A more efficient decoration of isolated vacancy-type defects is realized when Wu is employed as a radioisotopic tracer in the decoration step, however, the rapid diffusivity of these smaller species leads to less sharply defined radiocopper profiles. Both the neutron activation and radiotracer modifications of the technique yield damage profiles which are significantly shallower than the corresponding implanted impurity profiles.     

Reactive Compatibilization of Poly(Butylene Terephthalate)/Acrylonitrile-Styrene-Acrylate Blends by Epoxy Resin: Morphology and Mechanical Properties

The effect on the notched Izod impact strength of poly(butylene terephthalate) (PBT) by blending it with acrylonitrile-styrene-acrylate (ASA) was examined. Epoxy resin (ER) was demonstrated to be an efficient compatibilizer for the partially compatible blends of PBT/ASA. It requires only a very small amount of ER to improve the toughness of the PBT/ASA blends drastically. Furthermore, there exists an optimum proportion of ER added to achieve maximum notched Izod impact strength. Transmission electron microscopy (TEM) observation suggests that the ER in the PBT/ASA/ER blends suppressing the tendency of coalescence of ASA, leading to better dispersion of the ASA particles. Field emission scanning electron microscopy (FESEM) shows that ER enhances the phase dispersion and the interfacial adhesion between the PBT and ASA phases, it improves the compatibility between PBT and ASA. The compositions in the interphase was continuous, which results in multiphase composites with a graded interphase. It is suggested that enhanced interphase adhesion was necessary to obtain improved dispersion, fine phase morphology, and better toughness.     

The dependence of structure and properties of polycrystalline diamonds (PCD) on the conditions of their production

Abstract

AES and SIMS were used to analyze the diamond powders surface composition using LAS-3000 device. It is found that impurities on diamond particles surfaces have a detrimental effect on the PCD sintering and physico-mechanical properties of the product.