硝酸浓度对中高压铝阳极箔比容的影响

在不同浓度的硝酸中制备铝阳极箔样品,并通过失重量、电化学交流阻抗及扫描电镜方法对样品进行了表征,重点探讨了硝酸的浓度对所制阳极箔比容的影响。结果表明:当硝酸的浓度为1.5 mol/L时,比容达到了一个相对较大的值2.01×10–6 F/cm2;交流阻抗谱中,只出现了一个时间常数,且表现出类似常相位角元的特征。     

二硫化四甲基秋兰姆的表面增强拉曼光谱研究

制备了两种简单常用的具有表面增强拉曼(SERS)活性的银基底—银镜和硝酸刻蚀银箔,并应用于二硫化四甲基秋兰姆(福美双)的检测及其结构变化的分析。SERS技术提供了不同浓度下的二硫化四甲基秋兰姆分子的振动信息,发现当其与金属银基底作用后,二硫键断裂,并且通过化学作用吸附在银基底表面。通过分析不同浓度福美双分子吸附在银表面的拉曼光谱,证明其在金属表面存在两种吸附方式即表现为单齿形和双齿形两种几何形状。这些光谱及结构信息有助于理解和检测自然环境中二硫化四甲基秋兰姆及其分解产物。同时也对二硫代氨基甲酸盐类化合物的研究有一定的借鉴意义。     

Study of energy deposition and stripper temperature for CYCIAE-100

Nowadays high intensity proton accelerators are extensively applied, and this paper gives particular emphasis on CYCIAE-100, a 100 MeV high intensity compact cyclotron being constructed at CIAE. For accelerators of this type, the study is focused on how to improve the beam intensity. As for CYCIAE-100, the charge-exchange extraction is used to get protons. So it is crucial to enhance the lifetime of the stripping foil, which is largely determined by the energy deposition on it. For this cyclotron, due to the influence of the magnetic field, the electrons will spin near the foil and lose energy each time when they cross the foil. The energy deposition refers to all the energy deposition of protons and electrons. This paper stresses the stripper study of CYCIAE-100, in which the particle distribution on the foil is simulated and the energy deposition of the protons and electrons stripped from the H- ions are calculated. The temperature distributions are then calculated as a main reference for the foil design.     

Angle-dependent ultraviolet photoelectron spectroscopy of sputter cleaned polycrystalline noble metals

Polycrystalline noble metal films are commonly used in practical applications across a variety of different fields. However, the surface electronic structure of the noble metals has primarily only been studied on single crystal substrates. In addition, sputter cleaned polycrystalline noble metal films are commonly used substrates in ultraviolet photoelectron spectroscopy (UPS) studies, but have yet to be systematically studied in terms of their photoemission anisotropy. The angle-dependence of the valence band spectra of sputter cleaned polycrystalline Au, Ag and Cu were studied using angle-resolved UPS. It is found that the photoemission is anisotropic with respect to photoelectron take-off angle. The results for Ag and Cu are in good agreement with previous reports of surface d-band narrowing in polycrystalline noble metal films. However, significant anisotropies in the d-band, s-band and Fermi edge of sputter cleaned Au are observed, which cannot be attributed to surface d-band narrowing alone. The unusual results for Au are attributed to drastic changes in the film morphology near the surface as a result of sputter cleaning.     

氧化膜形貌对铝电解电容器寿命的影响

对三种高压阳极化成铝箔进行了SEM的形貌和EDS组分分析,用三种铝箔分别制成400 V,6 800 霧电容器并进行了耐久性试验对比,对电容器性能和阳极化成铝箔氧化膜形貌之间的关系进行了探讨。结果表明:隧道腐蚀铝箔的氧化膜残存的杂质离子多,容易击穿;氧化膜表面过多的羟基对电容器的漏电流影响很大。     

密度泛函理论预测微量元素在Al(100)表面的偏聚

通过周期性层状模型, 利用密度泛函理论预测了微量杂质元素原子M(M=Fe, Si, Mg, Cu, Mn, Ga, In, Sn, Pb)在高纯铝箔(100)表面的偏聚趋势. 计算得到表面偏聚能与已有实验结果相吻合. 表面偏聚能由表面取代的微量元素原子M的位置、原子半径和金属的表面能决定. 当表面偏聚能为负时, 微量元素原子M在表面偏聚, 反之则杂质原子不发生表面聚集. 微量元素原子在铝箔表面偏聚可以使铝箔表面产生大量的缺陷和位错, 它们在铝箔腐蚀时容易成为腐蚀的形核起点, 进而增加铝箔的腐蚀发孔密度.     

辐射场非平衡性对CH薄膜烧蚀特性的影响

 为研究辐射场非平衡性对ICF内爆靶丸辐射烧蚀效果的影响,在普朗克谱的高频区（Au的M带）叠加高斯谱人为地构造辐射源的能谱,利用1维多群辐射输运流体力学程序RDMG模拟CH薄膜的烧蚀过程,考察烧蚀压、预热、压缩比、冲击波速度等物理量受辐射场非平衡性的影响。模拟结果表明,Au的M带辐射有明显的增强预热、减小冲击波压缩比的作用,从而间接地影响了烧蚀冲击波的速度。     

Resonance enhanced multi-photon ionization of neutral atoms sputtered with Ga-FIB

Resonance enhanced multi-photon ionization (REMPI) of neutral aluminum atoms sputtered with gallium focused ion beam (Ga-FIB) was studied in terms of substrate temperature and chemical state of the surfaces. Aluminum has the lowest excitation state (3p ²P_3/2) at 112 cm⁻¹ above the ground state (3p ²P_1/2). The results showed that the total REMPI signal intensity of neutral aluminum atoms and the ratio of REMPI signal intensities attributed to ²P_1/2 to ²P_3/2 were increased at higher temperature. On the other hand, the REMPI signal and the ratio were decreased in the case of partially oxidized aluminum surfaces. Considering the result on Al₂O₃, it was confirmed that the REMPI signals of ground state ²P_1/2 and the first excited spate ²P_1/2 could be affected with surface oxidation state.     

Complete and incomplete fusion studies in7Li and16O induced reactions on51V by measurement of excitation functions and recoil ranges

Excitation function and mean projected recoil ranges of nuclei produced in the⁷Li and¹⁶O induced reactions on⁵¹V target were measured by conventional stacked foil and thick-target thick-recoil-catcher technique for bombarding energiesE ≤ 50.0 MeV for⁷Li ions andE ≃ 60.0-96.0 MeV for the¹⁶O ions. The measured recoil ranges are converted to momentum transfer. The momentum transfer information was used to get clues about some aspects of the interaction such as complete and incomplete fusion reaction mechanism which correspond to full and reduced momentum transfer respectively. The measured excitation functions are compared with the calculation based on the statistical model which describes only equilibrium decay of the compound nucleus using the CASCADE code. The comparison of the CASCADE code with the measured excitation functions for the residue radioisotopes⁵¹Cr and⁵⁴Mn for the⁷Li +⁵¹V system indicates the reaction mechanisms is complete fusion of⁷Li with the target nucleus⁵¹V. Similarly the comparison of the CASCADE code with the measured excitation functions of the residue radioisotopes for the system¹⁶O +⁵¹ V indicates that the four reaction mechanisms (i) complete fusion of¹⁶O, (ii) incomplete fusion of¹²C, (iii) incomplete fusion of⁸Be and (iv) incomplete fusion of⁴He respectively with the target might be contributing to reaction cross sections.     

衍射光学可变图像在高安全产品中的应用

本文介绍了我们在高安全产品中采用的综合衍射光学可变图像方法,它们包扦人彩色动态合成全息图、高安全级别的动态点阵全息图,脉冲激光全息图等。该综合技术被划分为不同级的别以满足国内,外不同客户和安全产品的需要。