离子辐照与碳纳米结构体的合成

阐述了在离子辐照下生成各种碳纳米结构体研究的发展现状,探讨了相应的生长机制和一些相变机理 ,提出了一些有待解决的问题 ,并对其发展方向作了展望. The synthesis of carbon nanostructures, such as fullerenes, nanotubes, onions and diamond, by using ion irradiation, has been reviewed and the growth mechanisms of these carbon nanostructures as well as their phase transitions are simply discussed. It shows that high density plasma engendered by ion irradiation plays an important role in the growing of carbon nanostructures. In addition, it indicates that ion irradiation, due to its great flexibility of experimental parameters, is enormously convenient in...     

康普顿背散射技术对贮存环电子束诊断及其应用——I电子束能量的精确测量及光学标准实验站

简单叙述了采用康普顿背散射技术精确测量电子束能量的技术,并指出建立辐射标准实验站对精确电子束能量测量的需求. The technique to measure the electron beam energy accurately with Compton backscattering technique is introduced and requirements for the experimental stations of radiometry are also described in the paper.     

F同位素的反应总截面测量和17F可能的质子皮结构

应用透射法对中能区F同位素与C靶的反应总截面进行了测量。发现^17F的反应总截面比其邻近同位素的反应总截面稍有增强。用Glauber模型和BUU模型对F同位素进行了差异因子d的分析。^17F的差异因子d比共附近同位素稍有增强。分析结果表明^17F可能存在质子皮结构。     

Isoscaling behavior studied by HIPSE model

The isoscaling behavior in the reaction system of 58,64Ni + 9Be has been studied by using the heavy-ion phase-space exploration(HIPSE) model. The extracted isoscaling parameters α and β for both heavy and light fragments for HIPSE model calculations are in good agreement with recent experimental data. The investigation shows that the parameters in the HIPSE model have some effect on the isoscaling parameter. The isoscaling parameters for hot and cold fragments have been extracted.     

Scaling property in one-nucleon removal reactions induced by exotic nuclei

Assuming a core plus valence nucleon structure, one-nucleon removal reaction is investigated within the framework of few-body Glauber theory. Fermi-type distribution is used for the core density, while the wavefunction of the valence nucleon is calculated by solving the single particle eigenvalue problem of the SchrSdinger equation with the Woods-Saxon potential. The parallel momentum distribution （P//） of the fragments is calculated for isotopes with 3 〈 Z 〈 18. A remarkable scaling property is observed from the dependence of the dimensionless quantity P^2 v/R^2 e on the full width at half maximum of the parallel momentum distribution （FWHMp//）. R^2 v/R^2 c is a measure of the exotic extent of the nuclear halo. Based on the obtained 2 2 scaling law, FWHMp// can be used as an experimental observable to extract R^2 v/R^2 c and measure the exotic extent for the nuclear halo.     

Strangeness by Thermal Model Simulation at RHIC

The local temperature effect on strangeness enhancement in relativistic heavy ion collisions is discussed in the framework of the thermal model in which the K^＋ /h^＋ ratio becomes smaller with increasing freeze-out temperature. Considering that most strangeness particles of final-state particles are from the kaon meson, the temperature effect may play a role in strangeness production in hot dense matter where a slightly different temperature distribution in different areas could be produced by jet energy loss. This phenomenon is predicted by thermal model calculation at RHIC energy. The /Ф ratio in central Au＋Au collisions at 200GeV from the thermal model depends on the freeze-out temperature obviously when γs is different. It should be one of the reasons why strangeness enhancements of and Ф are different though they include two strange quarks. These results indicate that thermodynamics is an important factor for strangeness production and the strangeness enhancement phenomenon.     

Isoscaling Behavior in ^48,40Ca＋^9Be Collisions at Intermediate Energy Investigated by the HIPSE Model

The fragment production cross sections for 140 Me V/nucleon ^48,40 Ca^＋9 Be reactions are calculated by the heavyion phase space exploration （HIPSE） model. Isoscaling behavior is observed. The isoscaling parameters a and β for both heavy and light fragments from the HIPSE model calculations are in good agreement with the experimental data. It is shown that the potential parameters in the HIPSE model have very little effect on the isoscaling parameters. The effect of the excitation energy and evaporation on the isoscaling behavior is also discussed.     

相对论重离子碰撞的输运模型研究

美国的布鲁克海文国家实验室相对论重离子对撞机（RHIC）和欧洲核子中心的大型强子对撞机（LHC）的大量实验结果表明,在相对论重离子碰撞中已经产生了一种近似完美流体的强耦合部分子物质。基于一个多相粒子输运模型（AMPT）理论工具,对RHIC和LHC实验上的一些重要结果的开展了三个方面的理论研究工作（集体流、喷注淬火、手征磁效应）,研究结果揭示了初始的夸克胶子等离子体（QGP）能量密度涨落经过部分子输运演化产生末态粒子的各阶次的集体流、喷注和部分子物质的相互作用导致喷注的能量损失、末态相互作用严重影响手征磁效应的大小等物理过程作用机制。The experimental results from the BNL Relativistic Heavy Ion Collider (RHIC) and the CERN Large Hadron Collider (LHC) show that a nearly perfect fluid (i.e. strong-coupling Quark Gluon Plasma) has been created in relativistic heavy-ion collisions. I introduce our theoretical results based on a multi-phase transport (AMPT) model. Several important topics such as collective flow, jet quenching, chiral magnetic effect, are addressed. The simulation results indicate that the initial fluctuations of energy density of the QGP lead to all orders of harmonic flows of final particles via parton cascade, the strong interactions between jet and the QGP make jet lose much energy, and the final state interactions play an important role to affect the initial chiral magnetic effect in relativistic heavy-ion collisions.     

PDMS表面织构润滑特性的研究

利用光刻-复模技术在PDMS表面制作凹坑阵列型表面织构,并采用球-盘式摩擦试验机对具有不同尺寸凹坑阵列的试样进行摩擦试验,研究了软质材料表面织构在混合至流体动压润滑区域的润滑特性.结果表明:对于PDMS材料,凹坑直径是影响摩擦特性的主要因素之一.与无织构试样相比,在低速条件下(0.005m/s)的混合润滑区域较小直径(d=50μm)的织构能够减小摩擦,而较大直径(d=200μm)的织构表现出增大摩擦的效果.在试验范围内凹坑的面积率越大,表面织构的作用越显著.     

Differential cross sections of elastic electron scattering from CH4. CF4 and SF6 in the energy range l00-700eV

We investigate the differential cross sections （DCS） of elastic electron scattering from CH4, CF4 and SF6 at six impact energies in a range of 100 700eV by employing the independent atom model （IAM） together with the relativistic partial waves. The atom is present in an optical potential which is complex, spherically symmetric, and energy dependent. The optical potential of the atom is the sum of the direct static, dynamic polarization, local exchange and modified absorption potentials. The results obtained by using a modified absorption potential show significant improvements on the unmodified absorption potential results. The present results are generally in good agreement with experimental data available. In addition, the present results indicate that the structure of molecule manifests the observable effects on electron- molecule scattering.[第一段]