223 resultados para g-Fe2O3
Resumo:
We calculate the in-medium nucleon-nucleon scattering cross sections from the G-matrix using the Dirac-Brueckner-Hartree-Fock (DBHF) approach. And we investigate the influence of the different representations of the G-matrix to the cross sections, the difference of which is mainly from the different effective masses.
Resumo:
We experimentally investigate the shell effect on the stabilization processes following the multi-electron transfer in slow collisions of Arq+-Ar (q = 6-9, It) The relative cross-section ratios of multi-electron transfer and of the subsequent stabilization with respect to single-electron capture are measured meanwhile compared with the theoretical results predicted by the classical over-barrier model. Our result indicates that the multi-electron transfer is dominant when the projectile charge is large and the subsequent stabilization shows a dramatic variation if the projectile L-shell configuration becomes open. It shows that the subsequent stabilization processes of multiply excited scattering ions have a strong dependence on the projectile shell. (C) 2010 Elsevier BV All rights reserved.
Resumo:
Medium-spin states of Ge-70 have been studied via the Ni-60(C-12,2p gamma)Ge-70 reaction at 45 MeV. The ground-state band and the second 0(+) band have been extended to the 12(+) and 8(+) states, respectively. Two negative-parity bands, one of which has a coupled structure and the other has a decoupled structure, have been observed additionally. Although the latter decoupled structure was known up to the (21(-)) state from a previous experiment, the part of the level scheme up to the 15(-) state has been largely modified by the present experiment. Backbendings observed in the positive- and negative-parity yrast bands have been compared with those of the neighboring even Ge isotopes. The experimental level structure has been compared with the shell-model calculations in the model space (2p(3/2), 1f(5/2), 2(p1/2), 1g(9/2)) employing two kinds of effective interactions, one of which is an extended P + QQ interaction with monopole interactions and the other is developed from a renormalized G matrix. Microscopic structures of the observed bands have been discussed with the help of the shell-model calculations.
Resumo:
采用5台1.5W/4.2KG-M制冷机(日本住友RDK415D)并联研制出了1台方便实验室使用的小型氦液化装置,并为其建立了性能测量实验台。实验结果表明:液氦温度为4.17K(饱和压力为96kPa)时,氦液化率为74L/d;液氦温度为4.42K(饱和压力为121kPa)时,液化率为116L/d,经拟合,在4.2K(饱和压力为100kPa)时液化率为83L/d,并且通过100小时以上的连续运行,说明该氦液化装置自循环性能良好。通过实验发现:实测氦液化率远大于制冷机冷头制冷量对应的计算氦液化率。分析认为:G-M制冷机气缸壁对氦气预冷是提高实际氦液化率的主要因素。
Resumo:
本论文在 166MeV 的束流能量下,利用重离子熔合蒸发反应 142 Nd(32 S, 1p3nγ )170 Re 布居了 170 Re 的高自旋激发态,用 12 套带 BGO反康普顿抑制的高 纯锗探测器阵列进行了在束 X-γ 和γ γ − 符合测量。在 210MeV 的束流能量下, 利用重离子熔合蒸发反应 146 Nd(35 Cl,5nγ )176 Ir 产生具有 β+ / EC 衰变性质的 核素 176 Ir, 由氦喷嘴快速带传输系统将反应产物送到低本底区,用一台小平面探 测器、一台轴对称型高纯锗探测器和一台 CLOVER 探测器进行了γ γ − 符合和 t γ − 单谱测量。基于这些测量结果,研究了 170 Re 的高自旋态和 176 Ir 的 β+ / EC 衰变性质。 本工作基于γ−γ符合关系及周围邻近核已知信息的综合分析,首次建立了包 括 16 个能级 26 条γ 跃迁的双奇核 170 Re 的转动带能级纲图,并利用推转壳模型、 粒子转子模型等对其进行了分析和讨论。根据实验提取出的准粒子顺排、 Routhian、旋称劈裂等结构信息和邻近双奇核带结构系统学知识的比较分析,指 出该带的两准粒子组态是 11/213/2 hi π ν ⊗ ,并且该带在低自旋出现旋称反转。 基于对 176 Ir 核 β+ / EC衰变实验数据的离线处理分析,对早先发表的 176 Ir 衰 变γ 跃迁进行确认的同时又发现了 4 个新能级和 13 条新的γ 射线,丰富了 176 Os 核的低位激发态能级纲图。根据典型γ 射线的衰变时间谱建议了 176 Ir核的一个长 寿命低自旋同核异能态,同时通过两准粒子耦合的半经验计算建议了其组态。
Resumo:
The direct reduction of SO2 to elemental sulfur in flue gas by the coupling of cold plasma and catalyst, being a new approach for SO2 reduction, was studied. In this process, CO2 can be disassembled to form CO, which acts as the reductant under the cold plasma. With the coupling of the cold plasma and the catalyst, sulfur dioxide was selectively reduced by CO to elemental sulfur with a byproduct of metal sulfate, e.g., FeSO4. In the present work, Fe2O3/gamma-Al2O3 was employed as the catalyst. The extent of desulfurization was more than 80%, and the selectivity of elemental sulfur is about 55%. The effects of water vapor, temperature, and the components of simulated flue gas were investigated. At the same time, the coupling of thermogravimetry and infrared method and a chemical analysis method were employed to evaluate the used catalyst. In this paper, we will focus on the discussion of the catalyst. The discussions of the detail of plasma will be introduced in another paper.
Resumo:
The selective catalytic reduction of NO by CH4 was compared over In-Fe2O3/HZSM-5 catalysts prepared by impregnation and co-impregnation methods. It was found that the catalyst preparation method greatly affected the catalyst activity. The impregnated catalyst was very active, but the co-impregnated one showed poor activity. The In Fe2O3/HZSM-5 catalysts were investigated by Mossbauer spectroscopy. The results showed that indium cations entered into the iron oxide lattice in the co-impregnated catalyst, while the impregnated catalyst exhibited a more stable structure, when both of the catalysts were treated severely in the reaction atmosphere. Characterization by means of combined in situ temperature programmed reduction (TPR)- Mossbauer spectroscopy further revealed that the performances of the two catalysts were different in the TPR processes.