Constraints on the symmetry energy and neutron skins from pygmy resonances in Ni-68 and Sn-132

Correlations between the behavior of the nuclear symmetry energy, the neutron skins, and the percentage of energy-weighted sum rule (EWSR) exhausted by the pygmy dipole resonance (PDR) in Ni-68 and Sn-132 are investigated by using different random phase approximation (RPA) models for the dipole response, based on a representative set of Skyrme effective forces plus meson-exchange effective Lagrangians. A comparison with the experimental data has allowed us to constrain the value of the derivative of the symmetry energy at saturation. The neutron skin radius is deduced under this constraint.

Au LX射线发射截面和Al、Ti、Ni表面可见、红外光谱测量

本实验工作是在中国原子能科学研究院的HI-13串列加速器国家实验室第二测量厅原子物理实验平台上完成。本工作采用能量为20-50MeV的高电荷态O5+离子去轰击Au, 测量了不同能量下Au的L1、Lα、Lβ、Lγ的X射线谱，计算了不同能量下各条X射线的产生截面，并与ECPSSR理论计算结果进行了比较。实验结果表明σ（Ll）/σ(Lα) 和σ（Lγ）/σ(Lα)与ECPSSR理论计算结果符合比较好，而对于σ（Lβ）/σ(Lα)，在较低能区实验值略高于理论值。在中国科学院近代物理研究所320kV高电荷态离子实验研究平台上测量了Xeq+ (q=17-29)入射Al、Ti和Ni等表面诱发的可见光和红外光。通过对靶原子光谱线的研究，实验发现，随着入射离子的电荷态增高，原子和离子的各种光谱线可得到有效地激发。低速高电荷态离子入射金属固体表面，靶原子的特征谱线的激发强度，与入射离子的电荷态q密切相关。qc的实验测量值和理论计算值符合的较好

96 MEV能量下~(16)O + ~(94)Ni反应机制研究

The pro sectile-like fragments of ~(16)O + ~(64)Ni Reaction (Elab = 96 MeV) were measured by using ionization chamber telescopes. The countour plots of d~36/dndEdz in TKE-θ plane angular distribution integrating over different TKE window. The z-distribution and angular distributions of different fragments from He to O were obtained. The main mechanisms dominating in this reaction were discussed

（一）兰州重离子加速器束流能量、能散测量（二）中能~(12)C + ~(64)Ni, ~(58)Ni碎裂反应的实验研究

本论文通过讨论选择了简单易行的弹性散射法来测量兰州重离子加速器流能量、能散，描述了整个实验的准备、进行及数据处理，并讨论、修正了所得的实验结果，得到了~(12)C束流能散为(2.74 ± 0.14) * 10~(-2)，能量经刻度为每核子46.4MeV/u。本工作还拟采用飞行时间法来测量束流能量的绝对值，以检验弹性散射法测得的能量值，而且已设计制作了用作起始探测器的微道板（MCP）零时探测器，上器进行了必要的高调试，用MCP零时探测器作为起始探测器，Si半导体探测器作为终止探测器，对于10MeV/uα粒子，得到了好于560ps的总时间分辩，完全可用于中能重离子实验探测

46.7 MeV/u~(12)C轰击~(58)Ni、~(115)In、~(197)Au反应中粒子发射研究中子皮及中子分布弥散度对核势的影响

用能量密度公式及小液滴模型给出的费米密度分布，并引入中子皮及中子分布弥散度随中子过剩自由度增加而增加这一因素，计算了重离子反应在相互作用势及熔合位垒。熔合位垒的计算值和实验值符合很好，特别是在中重核区域，改善了以前的计算结果。详细研究了亲近势标度，发现用中子皮及中子分布弥散度的变化能较好地解释中子过剩自由度对新近势标度偏离的影响。本工作对奇异核结构与核反应性质的研究无疑是有用的。我们利用HIRFL提供的46.7MeV/u ~(12)C束轰击~(58)Ni、~(115)In、~(197)Au研究了反应中发射的α粒子角分布和能谱。从速度表象中洛仑兹不变截面等高图中明显看到发射α粒子的三个源。用这三个源的运动模型成功拟合了α粒子能谱，所提取的参数符合费米气体模型计算结果，并讨论了能谱及拟合参数对靶的依赖关系。认为快速源实质上来自弹核碎裂或类弹核碎裂

Morphology observation of carbon deposition by CH4 decomposition over Ni-based catalysts

We found a novel morphology variation of carbon deposition derived from CH4 decomposition over NI-based catalysts. By altering the chemical composition and particle size of Ni-based catalysts, carbon filaments, nanofibres and nanotubes were observed over conventional Ni/y-Al2O3, Ni-Co/gamma-Al2O3 and nanoscale Ni-Co/gamma-Al2O3 catalysts, respectively. The simple introduction of Co into a conventional Ni/gamma-Al2O3 catalyst can vary the carbon deposition from amorphous filamentous carbon to ordered carbon fibres. Moreover, carbon nanotubes with uniform diameter distribution can be obtained over nanosized Ni-Co/gamma-Al2O3 catalyst particles. In addition, the oxidation behaviour of the different deposited carbon was studied by using a temperature-programmed oxidation technique. This work provides a simple strategy to control over the size and morphology of the carbon deposition from catalytic decomposition of CH4.

Correlation between the characteristics and catalytic performance of Ni-V-O catalysts in oxidative dehydrogenation of propane

Ni - V - O series catalysts for the oxidative dehydrogenation (ODH) of propane were prepared and characterized by BET, XRD, H-2- TPR, O-2-TPD-MS and electrical conductivity. At 425 degreesC a C3H6 selectivity of 49.9% was observed on Ni0.9V0.1OY at a C3H8 conversion of 19.4%, and the obtained selectivity is almost two times higher than that over NiO at the roughly same conversion of C3H8. The mobile oxygen species created by the interaction of NiO and V2O5 has been found in the composite catalysts by O-2-TPD-MS and electrical conductivity studies, which seems to be responsible for the enhanced selectivity of the propane oxidative dehydrogenation.

On-line voltammetric monitoring of dissolved Cu and Ni in the Gulf of Cadiz, south-west Spain

Geochemical processes in estuarine and coastal waters often occur on temporally and spatially small scales, resulting in variability of metal speciation and dissolved concentrations. Thus, surveys, which are aimed to improve our understanding of metal behaviour in such systems, benefit from high-resolution, interactive sampling campaigns. The present paper discusses a high-resolution approach to coastal monitoring, with the application of an automated voltammetric metal analyser for on-line measurements of dissolved trace metals in the Gulf of Cadiz, south-west Spain. This coastal sea receives metal-rich inputs from a metalliferous mining area, mainly via the Huelva estuary. On-line measurements of dissolved Cu, Zn, Ni and Co were carried out on-board ship during an eight-day sampling campaign in the study area in June 1997. A pumping system operated continuously underway and provided sampled water from a depth of ca. 4 m. Total dissolved metal concentrations measured on-line in the Gulf of Cadiz ranged between <5 nM Cu (<3 nM Ni) ca. 50 km off-shore and 60–90 nM Cu (5–13 nM Ni) in the vicinity of the Huelva estuary. The survey revealed steep gradients and strong tidal variability in the dissolved metal plume extending from the Huelva estuary into the Gulf of Cadiz. Further on-line measurements were carried out with the automatic metal monitor from the bank of the Odiel estuary over a full tidal cycle, at dissolved metal concentrations in the μM range. The application confirmed the suitability of the automated metal monitor for coastal sampling, and demonstrated its adaptability to a wide range of environmental conditions in the dynamic waters of estuaries and coastal seas. The near-real time acquisition of dissolved metal concentrations at high resolution enabled an interactive sampling campaign and therefore the close investigation of tidal variability in the development of the Huelva estuary metal plume.

Crystallographic and electrochemical characteristics of melt-spun Ti-Zr-Ni-La alloys

Ti-based icosahedral quasicrystalline phase (I-phase) exhibited excellent hydrogen storage property for special structure. Unfortunately, the application as the negative electrode material of the nickel-metal hydride batteries was limited due to the poor electrochemical kinetics. Meanwhile, rare-earth element was beneficial to the electrochemical properties of Ti, Zr-based alloy.