分类: 核科学技术 >> 粒子加速器 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要: Proton radiography experiment with a Zumbro lens system was carried out on an 11 MeV proton cyclotron. The experimental results show that the image blurring is improved markedly. Clear images and good spatial resolution of the density step edges are obtained, which is important for hydrotest experiments, and the spatial resolution can achieve 100 m.
分类: 核科学技术 >> 粒子加速器 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要: Differing from radiography without lens system, the high-energy proton radiography (PRAD) uses Zumbro lens system to focus the penetrating protons. Since the Zumbro lens system is able to limit the range of multiple Coulomb scattering angles of the protons, the low-energy PRAD with Zumbro lens system is also feasible, although the attenuation of probing protons in the object is negligible. Low-energy PRAD is superior to the high-energy PRAD for diagnosing the objects of small thicknesses. To verify the imaging principle of Zumbro lens system, 11 MeV PRAD experiments were performed at the China Academy of Engineering Physics (CAEP) recently. The experiment results demonstrated that this 11 MeV PRAD was able to radiograph objects of area density less than 2.7�10-2 g/cm2 and the area density discrepancy less than 2.3% could be distinguished.
分类: 化学 >> 物理化学 提交时间: 2017-11-05 合作期刊: 《结构化学》
摘要: Using 4΄-methoxy-5-hydroxyisoflavone and 4΄,5-dihydroxy-7-methoxyisoflavone as leding compounds, 6-methoxy-2H-phenanthro[9,10-c]pyrazol-11-ol (1a) and 9-methoxy-2H-phenanthro [9,10-c]pyrazol-6,11-diol (1b) were synthesized by two dehydration processes in the EtOH solution. They were characterized by IR, 1H NMR and 13C NMR. The black prism crystal of 1a was grown by the slow solvent evaporation technique from 40:1 (v/v) CHCl3/MeOH, and it was determined by single-crystal X-ray diffraction. In the crystal structure, 1a was stabilized by intramolecular (O–H···N) and intermolecular (N–H···O, O–H···O, π···π, C–H···π) interactions. In addition, the fluorescence properties of 1a and 1b in the base and neutral media revealed that they possessed excited state intramolecular proton transfer phenomena (ESIPT).