2009年 第26卷 第1期
2009, 26(1): 1-7.
doi: 10.11804/NuclPhysRev.26.01.001
摘要:
应用量子路径积分的方法，分析了高能重离子碰撞产生的高重子数密度粒子发射源的２K
和2π干涉学（hanbury Brown Twiss，HBT关联）。利用相对论流体动力学描述源的演化，采用的状态方程包含QGP到强子相的一级相变和对强子气体的体积修正。在２π关联的计算中考虑了激发态粒子衰变和多重散射效应，并将其HBT关联半径和寿命与传统热冻结模型的结果进行了对比。计算表明，早期化学冻结产生的K介子的HBT关联半径比２π关联的HBT关联半径小。激发态粒子的衰变使HBT关联半径和寿命增加，而多重散射对HBT关联的结果几乎没有影响。Using quantum pathintegral formulae， we examined the twokaon and twopion HanburyBrownTwiss (HBT) interferometry for the particleemitting source with high baryon density. The evolution of the source is described by relativistic hydrodynamics. We use an equation of state of firstorder transition from QGP to hadronic phase and consider a volume correction for the hadronic gas. The twopion HBT results with effects of excitedparticle decay and multiple scattering were investigated and compared with those for conventional thermal freeze out (TFO) model. We found that the twokaon HBT radius was smaller than those of the two pion interferometry. The particle decay increases the HBT radius and lifetime， while the effect of multiple scattering on HBT results can be neglected.
应用量子路径积分的方法，分析了高能重离子碰撞产生的高重子数密度粒子发射源的２K
和2π干涉学（hanbury Brown Twiss，HBT关联）。利用相对论流体动力学描述源的演化，采用的状态方程包含QGP到强子相的一级相变和对强子气体的体积修正。在２π关联的计算中考虑了激发态粒子衰变和多重散射效应，并将其HBT关联半径和寿命与传统热冻结模型的结果进行了对比。计算表明，早期化学冻结产生的K介子的HBT关联半径比２π关联的HBT关联半径小。激发态粒子的衰变使HBT关联半径和寿命增加，而多重散射对HBT关联的结果几乎没有影响。Using quantum pathintegral formulae， we examined the twokaon and twopion HanburyBrownTwiss (HBT) interferometry for the particleemitting source with high baryon density. The evolution of the source is described by relativistic hydrodynamics. We use an equation of state of firstorder transition from QGP to hadronic phase and consider a volume correction for the hadronic gas. The twopion HBT results with effects of excitedparticle decay and multiple scattering were investigated and compared with those for conventional thermal freeze out (TFO) model. We found that the twokaon HBT radius was smaller than those of the two pion interferometry. The particle decay increases the HBT radius and lifetime， while the effect of multiple scattering on HBT results can be neglected.
2009, 26(1): 8-12.
doi: 10.11804/NuclPhysRev.26.01.008
摘要:
利用改进的同位旋相关的量子分子动力学(ImIQMD)模型程序，对能量在库仑位垒附近的48Ca+208Pb反应系统进行了模拟。 计算得到的俘获截面、 准裂变截面和碎片分布及其发生的时间分布等结果与实验数据符合较好。 同时还得到了准裂变过程中发射第三个较大碎片的截面， 并简单讨论了它们的发射机制。Based on the improved isospin dependent quantum molecular dynamics (ImIQMD) model，the reaction of 48Ca+208Pb at energies near the Coulomb barrier was investigated systematically. The capture cross section，the quasifission cross section, the mass distribution of the quasifission fragments and the time for quasifission happened were obtained. According to the comparison with experimental data，the calculated capture cross sections and the fragment distributions of the quasifission were reasonable. Additionally，we got the cross sections of the third largest fragment，and the emission mechanism was also discussed briefly.
利用改进的同位旋相关的量子分子动力学(ImIQMD)模型程序，对能量在库仑位垒附近的48Ca+208Pb反应系统进行了模拟。 计算得到的俘获截面、 准裂变截面和碎片分布及其发生的时间分布等结果与实验数据符合较好。 同时还得到了准裂变过程中发射第三个较大碎片的截面， 并简单讨论了它们的发射机制。Based on the improved isospin dependent quantum molecular dynamics (ImIQMD) model，the reaction of 48Ca+208Pb at energies near the Coulomb barrier was investigated systematically. The capture cross section，the quasifission cross section, the mass distribution of the quasifission fragments and the time for quasifission happened were obtained. According to the comparison with experimental data，the calculated capture cross sections and the fragment distributions of the quasifission were reasonable. Additionally，we got the cross sections of the third largest fragment，and the emission mechanism was also discussed briefly.
2009, 26(1): 13-18.
doi: 10.11804/NuclPhysRev.26.01.013
摘要:
利用R矩阵理论程序， 采用数值计算方法， 通过拟合实验测量的中重核激发函数， 确定光学模型势， 提取共振态的共振能量、 衰变宽度等。 计算了共振弹性散射激发态的谱因子， 并和其它实验提取的谱因子数据进行了比较， 得到了和实验一致的结果。 此方法将来可以推广到轻核以及非束缚核的研究中去。 In this article， the experimental excitation function has been simulated in the numerical method based on R matrix theory and optical model potential， the decay energy and decay partial width of the resonant states have been obtained. Then the spectroscopic factor of the excited state in resonance elastic scattering reaction has been calculated， and it was compared with other experimental results， it shows a good agreement with the experimental data.
利用R矩阵理论程序， 采用数值计算方法， 通过拟合实验测量的中重核激发函数， 确定光学模型势， 提取共振态的共振能量、 衰变宽度等。 计算了共振弹性散射激发态的谱因子， 并和其它实验提取的谱因子数据进行了比较， 得到了和实验一致的结果。 此方法将来可以推广到轻核以及非束缚核的研究中去。 In this article， the experimental excitation function has been simulated in the numerical method based on R matrix theory and optical model potential， the decay energy and decay partial width of the resonant states have been obtained. Then the spectroscopic factor of the excited state in resonance elastic scattering reaction has been calculated， and it was compared with other experimental results， it shows a good agreement with the experimental data.
2009, 26(1): 19-22.
doi: 10.11804/NuclPhysRev.26.01.019
摘要:
非对易空间效应的出现引起了物理学界的广泛兴趣。 介绍了非对易空间中量子力学的代数关系，在所考虑的空间变量的对易关系中包含了坐标坐标的非对易性， 并且把 Moyal-Weyl 乘法在非对易空间中通过一个Bopp变换转变成普通的乘法。 然后给出了非对易空间中耦合谐振子的能级分裂情况。 The effect of noncommutativity of space have caused the physical academic circles widespread interest. In this paper， the noncommutative (NC) is introduced， which contain noncommutative of coordinatecoordinate， and find that the MoyalWeyl product in NC space can be replaced with a Bopp shift. Then， the energy splitting of the coupling harmonic oscillator in noncommutative spaces are discussed.
非对易空间效应的出现引起了物理学界的广泛兴趣。 介绍了非对易空间中量子力学的代数关系，在所考虑的空间变量的对易关系中包含了坐标坐标的非对易性， 并且把 Moyal-Weyl 乘法在非对易空间中通过一个Bopp变换转变成普通的乘法。 然后给出了非对易空间中耦合谐振子的能级分裂情况。 The effect of noncommutativity of space have caused the physical academic circles widespread interest. In this paper， the noncommutative (NC) is introduced， which contain noncommutative of coordinatecoordinate， and find that the MoyalWeyl product in NC space can be replaced with a Bopp shift. Then， the energy splitting of the coupling harmonic oscillator in noncommutative spaces are discussed.
2009, 26(1): 27-32.
doi: 10.11804/NuclPhysRev.26.01.027
摘要:
用多箔活化法测定了由AmBe中子源慢化屏蔽系统构成的中子活化在线分析系统样品处的中子能谱。 根据待测场点的中子注量率水平， 选用了5种非裂变核材料箔， 其中4种是中能区和热区的， 1种是快区的， 给出了各箔片的特性参数。 通过在待测场点对箔片进行辐照， 并测量其生成放射性核的γ放射性， 计算出了各箔片的活化率。 运用SANDII和MSIT迭代方法， 解出了待测场点的中子能谱。 详细分析了数据处理过程中群截面的加工处理以及由于自屏蔽效应引起的群截面修正问题； 研究了影响解谱精度的主要因素； 对解谱结果作了一定的分析讨论； 并用蒙特卡罗(MC)方法对最后的中子能谱做了不确定度分析。
用多箔活化法测定了由AmBe中子源慢化屏蔽系统构成的中子活化在线分析系统样品处的中子能谱。 根据待测场点的中子注量率水平， 选用了5种非裂变核材料箔， 其中4种是中能区和热区的， 1种是快区的， 给出了各箔片的特性参数。 通过在待测场点对箔片进行辐照， 并测量其生成放射性核的γ放射性， 计算出了各箔片的活化率。 运用SANDII和MSIT迭代方法， 解出了待测场点的中子能谱。 详细分析了数据处理过程中群截面的加工处理以及由于自屏蔽效应引起的群截面修正问题； 研究了影响解谱精度的主要因素； 对解谱结果作了一定的分析讨论； 并用蒙特卡罗(MC)方法对最后的中子能谱做了不确定度分析。
2009, 26(1): 23-26.
doi: 10.11804/NuclPhysRev.26.01.023
摘要:
s过程中的放射性核素中子俘获截面对天体核合成和核素丰度有重大影响， 在直接测量异常困难的情况下， 替代比率法是获得放射性核素中子俘获截面数据的一种间接新方法。 简单介绍了替代比率法理论， 并简要论述了用替代比率法推导中重核区放射性核素中子俘获截面的可行性。 The radioactive nuclei neutron capture cross section is very important to nuclearsynthesis and nuclide abundance in sprocess， but it is difficult to be measured directly because of the target production. A new method， surrogate ratio method which is developed from surrogate method， could be used to determine the cross section of radioactive nuclei neutron capture. In this paper， the surrogate ratio method was introduced and the feasibility was discussed to deduce the desired neutron capture cross sections with surrogate ratio method.
s过程中的放射性核素中子俘获截面对天体核合成和核素丰度有重大影响， 在直接测量异常困难的情况下， 替代比率法是获得放射性核素中子俘获截面数据的一种间接新方法。 简单介绍了替代比率法理论， 并简要论述了用替代比率法推导中重核区放射性核素中子俘获截面的可行性。 The radioactive nuclei neutron capture cross section is very important to nuclearsynthesis and nuclide abundance in sprocess， but it is difficult to be measured directly because of the target production. A new method， surrogate ratio method which is developed from surrogate method， could be used to determine the cross section of radioactive nuclei neutron capture. In this paper， the surrogate ratio method was introduced and the feasibility was discussed to deduce the desired neutron capture cross sections with surrogate ratio method.
2009, 26(1): 33-36.
doi: 10.11804/NuclPhysRev.26.01.033
摘要:
研究了CSRe电子冷却模式下使用线性质量刻度时， 空间电荷效应对测量精度的影响、 CSRe上测量190Ir质量的实验可行性以及估算了电子冷却模式下， 使用非线性刻度法所能达到的测量精度。 理论上的分析表明， CSRe在束流和二极铁磁场稳定的理想情况下， 如果电子冷却对同种离子束的冷却效果能达到δp/p=10－6量级， 采用非线性刻度的方法， 能够对像190Ir这样的重离子达到σ(m)/m≈10-8的测量精度。 Nuclear mass measurement by electron cooling mode in CSRe is discussed， mainly in three related aspects: the systematic error caused by the space charge effect in the case of linear mass calibration; the possibility of mass measurement of 190 Ir in CSRe; the estimation of the attainable precision in the case of nonlinear mass calibration. Theoretic analysis of the attainable precision shows that a precision of σ(m)/m≈10-8 can be achieved if the momentum spread of each kind of ions can be reduced to 10-6 in CSRe.
研究了CSRe电子冷却模式下使用线性质量刻度时， 空间电荷效应对测量精度的影响、 CSRe上测量190Ir质量的实验可行性以及估算了电子冷却模式下， 使用非线性刻度法所能达到的测量精度。 理论上的分析表明， CSRe在束流和二极铁磁场稳定的理想情况下， 如果电子冷却对同种离子束的冷却效果能达到δp/p=10－6量级， 采用非线性刻度的方法， 能够对像190Ir这样的重离子达到σ(m)/m≈10-8的测量精度。 Nuclear mass measurement by electron cooling mode in CSRe is discussed， mainly in three related aspects: the systematic error caused by the space charge effect in the case of linear mass calibration; the possibility of mass measurement of 190 Ir in CSRe; the estimation of the attainable precision in the case of nonlinear mass calibration. Theoretic analysis of the attainable precision shows that a precision of σ(m)/m≈10-8 can be achieved if the momentum spread of each kind of ions can be reduced to 10-6 in CSRe.
2009, 26(1): 37-40.
doi: 10.11804/NuclPhysRev.26.01.037
摘要:
介绍了用于中子探测器效率刻度的薄壁快脉冲252Cf裂变电离室。 在用飞行时间法测量中子能谱时， 该裂变电离室能够给出252Cf裂变中子发射时刻信号， 输出脉冲上升时间约为5.5 ns， 电离室由厚度为0.15 mm的不锈钢构成。 测试结果表明， 对裂变碎片的探测效率为99.2%， α粒子脉冲幅度和碎片脉冲幅度可清晰分开。A thin wall, fast pulse 252Cf ionization chamber, which was designed for calibrating efficiency of neutron detectors， was described. The ionization chamber can be used as the start detector in timeofflight measurements of the 252Cf fission neutron spectrum. The chamber is composed of 0.15 mm thick stainless steel, the rise time of pulse signals is about 5.5 ns. As the test result shows, the detection efficiency of fission fragments is 99.2%, and pulse signals caused by fissions are distinguished clearly from those caused by α decays.
介绍了用于中子探测器效率刻度的薄壁快脉冲252Cf裂变电离室。 在用飞行时间法测量中子能谱时， 该裂变电离室能够给出252Cf裂变中子发射时刻信号， 输出脉冲上升时间约为5.5 ns， 电离室由厚度为0.15 mm的不锈钢构成。 测试结果表明， 对裂变碎片的探测效率为99.2%， α粒子脉冲幅度和碎片脉冲幅度可清晰分开。A thin wall, fast pulse 252Cf ionization chamber, which was designed for calibrating efficiency of neutron detectors， was described. The ionization chamber can be used as the start detector in timeofflight measurements of the 252Cf fission neutron spectrum. The chamber is composed of 0.15 mm thick stainless steel, the rise time of pulse signals is about 5.5 ns. As the test result shows, the detection efficiency of fission fragments is 99.2%, and pulse signals caused by fissions are distinguished clearly from those caused by α decays.
2009, 26(1): 41-43.
doi: 10.11804/NuclPhysRev.26.01.041
摘要:
传统的X射线无损检测应用广泛， 但X射线对低原子序素构成为主的爆炸物不能进行有效的甄别； 中子穿透能力较强， 能和原子核相互作用产生特征γ射线， 因此中子无损检测方法能有效弥补X射线无损检测方法的不足。 介绍了几种常用的中子无损检测方法， 并采用脉冲快热中子法（为PFTNA）的方法对模拟爆炸物进行了测量。 实验结果表明， 利用密封中子发生器和采用PFTNA方法进行爆炸物检测是可行的。 Traditional Xray scatheless detecting method is used widely, but it is not useful to discriminate explosive consisting of low Z atomic elements. The penetrability of neutron is much better, and it can interact on atomic nucleus to emit characteristic γ ray. So neutron scatheless detecting methods can the used to detect the low Z atomic elements. In this paper, several neutron scatheless detecting methods are introduced briefly, and the principium experiment using Pulse Fast Thermal Neutron Analysis(PETNA) to detect a kind of explosive simulacrum is carried out. The experiment results show that PFTNA based on the sealed neutron generator is feasible to detect explosive.
传统的X射线无损检测应用广泛， 但X射线对低原子序素构成为主的爆炸物不能进行有效的甄别； 中子穿透能力较强， 能和原子核相互作用产生特征γ射线， 因此中子无损检测方法能有效弥补X射线无损检测方法的不足。 介绍了几种常用的中子无损检测方法， 并采用脉冲快热中子法（为PFTNA）的方法对模拟爆炸物进行了测量。 实验结果表明， 利用密封中子发生器和采用PFTNA方法进行爆炸物检测是可行的。 Traditional Xray scatheless detecting method is used widely, but it is not useful to discriminate explosive consisting of low Z atomic elements. The penetrability of neutron is much better, and it can interact on atomic nucleus to emit characteristic γ ray. So neutron scatheless detecting methods can the used to detect the low Z atomic elements. In this paper, several neutron scatheless detecting methods are introduced briefly, and the principium experiment using Pulse Fast Thermal Neutron Analysis(PETNA) to detect a kind of explosive simulacrum is carried out. The experiment results show that PFTNA based on the sealed neutron generator is feasible to detect explosive.
2009, 26(1): 44-47.
doi: 10.11804/NuclPhysRev.26.01.044
摘要:
在室温下用308 MeV的Xe离子和853 MeV的Pb离子辐照Ni/SiO2样品, 用卢瑟福背散射和X射线衍射技术对样品进行了分析。 通过分析Ni/SiO2样品中元素成分分布和结构随离子辐照剂量和电子能损的变化, 探索了离子辐照在Ni/SiO2样品中引起的界面原子混合与结构相变现象。 实验结果显示, Xe和Pb离子辐照均能引起明显的Ni原子向SiO2基体的扩散并导致界面附近Ni， Si和O原子的混合。 实验观测到低剂量Xe离子辐照可产生NiSi2相, 而高剂量Xe离子辐照则导致了Ni3Si和NiO相的形成。 根据热峰模型, Ni原子的扩散和新相的形成可能由沿离子入射路径强电子激发引起的瞬间热峰过程驱动。Ni/SiO2 interface were irradiated at room temperature with 308 MeV Xe ions to 1×1012, 5×1012 Xe/cm2 and 853 MeV Pb ions to 5×1011 Pb/cm2, respectively. These samples were analyzed using Rutherford Backscattering Spectrometry (RBS) and Xray diffraction spectroscopy (XRD), from which the intermixing and phase change were investigated. The obtained results show that both Xe and Pbions could induce diffusion of Ni atoms to SiO2 substrates and result in intermixing of Ni with SiO2. Furthermore, 1.0×1012 Xe/cm2 irradiation induced the formation of NiSi2 and 5.0×1012 Xe/cm2 irradiation created Ni3Si and NiO phases. The diffusion of Ni atoms and the formation of new phase may be driven by a transient thermal spike process induced by the intense electronic energy loss along the incident ion path.
在室温下用308 MeV的Xe离子和853 MeV的Pb离子辐照Ni/SiO2样品, 用卢瑟福背散射和X射线衍射技术对样品进行了分析。 通过分析Ni/SiO2样品中元素成分分布和结构随离子辐照剂量和电子能损的变化, 探索了离子辐照在Ni/SiO2样品中引起的界面原子混合与结构相变现象。 实验结果显示, Xe和Pb离子辐照均能引起明显的Ni原子向SiO2基体的扩散并导致界面附近Ni， Si和O原子的混合。 实验观测到低剂量Xe离子辐照可产生NiSi2相, 而高剂量Xe离子辐照则导致了Ni3Si和NiO相的形成。 根据热峰模型, Ni原子的扩散和新相的形成可能由沿离子入射路径强电子激发引起的瞬间热峰过程驱动。Ni/SiO2 interface were irradiated at room temperature with 308 MeV Xe ions to 1×1012, 5×1012 Xe/cm2 and 853 MeV Pb ions to 5×1011 Pb/cm2, respectively. These samples were analyzed using Rutherford Backscattering Spectrometry (RBS) and Xray diffraction spectroscopy (XRD), from which the intermixing and phase change were investigated. The obtained results show that both Xe and Pbions could induce diffusion of Ni atoms to SiO2 substrates and result in intermixing of Ni with SiO2. Furthermore, 1.0×1012 Xe/cm2 irradiation induced the formation of NiSi2 and 5.0×1012 Xe/cm2 irradiation created Ni3Si and NiO phases. The diffusion of Ni atoms and the formation of new phase may be driven by a transient thermal spike process induced by the intense electronic energy loss along the incident ion path.
2009, 26(1): 48-54.
doi: 10.11804/NuclPhysRev.26.01.048
摘要:
低活化的铁素体/马氏体钢是先进核能装置（如聚变堆）的重要候选结构材料。 在聚变堆实际工作环境下, 由于高温和高氦产生率引起的材料失效是这类材料面临的一个重要问题。 本项研究以兰州重离子加速器（HIRFL）提供的中能惰性气体离子束（20Ne， 122 MeV）作为模拟辐照条件， 借助透射电子显微镜， 研究了一种低活化的9Cr铁素体/马氏体钢（T92B）组织结构的变化和辐照肿胀。 实验结果表明， 高温下当材料中晶格原子的撞出损伤和惰性气体原子沉积浓度超过一定限值时， 材料内部形成高浓度的空洞， 并且空洞肿胀率显著依赖于辐照温度和剂量； 在马氏体板条界面及其它晶界处空洞趋于优先形成， 并且在晶界交汇处呈加速生长。 基于氦泡的形核生长与空洞肿胀的经典模型探讨了在不同辐照条件（He离子、 Ne离子、 Fe/He离子双束、 快中子、 Ni离子）下铁素体/马氏体钢中肿胀率数据的关联。Lowactivation Ferritic/Martensitic steels are a kind of important structural materials candidate to the application in advanced nuclear energy systems. Possible degradation of properties and even failure in the condition of hightemperature and high helium production due to energetic neutron irradiation in a fusion reactor is a major concern with the application of this kind of materials. In the present work microstructural evolution in a 9Cr Ferritic/Martensitic steel (T92B) irradiated with 122 MeV 20Ne ions at temperatures between 0.3—0.5 Tm (Tm is the melting point of the material) was investigated with transmission electron microscopy. High concentration voids were observed in the specimens irradiated at high temperatures when the displacement damage dose and Ne concentration exceed a certain level. Preferential formation of voids at lathboundaries and other grainboundaries was found. The data of void swellings in 9Cr ferritic/martensitic steels irradiated in different conditions (such as with Heions, Neions, Fe/He dual beams, fast neutrons, Niions etc.) were compiled and analyzed based on a classic model of helium bubble formation, and bubble to void transition.
低活化的铁素体/马氏体钢是先进核能装置（如聚变堆）的重要候选结构材料。 在聚变堆实际工作环境下, 由于高温和高氦产生率引起的材料失效是这类材料面临的一个重要问题。 本项研究以兰州重离子加速器（HIRFL）提供的中能惰性气体离子束（20Ne， 122 MeV）作为模拟辐照条件， 借助透射电子显微镜， 研究了一种低活化的9Cr铁素体/马氏体钢（T92B）组织结构的变化和辐照肿胀。 实验结果表明， 高温下当材料中晶格原子的撞出损伤和惰性气体原子沉积浓度超过一定限值时， 材料内部形成高浓度的空洞， 并且空洞肿胀率显著依赖于辐照温度和剂量； 在马氏体板条界面及其它晶界处空洞趋于优先形成， 并且在晶界交汇处呈加速生长。 基于氦泡的形核生长与空洞肿胀的经典模型探讨了在不同辐照条件（He离子、 Ne离子、 Fe/He离子双束、 快中子、 Ni离子）下铁素体/马氏体钢中肿胀率数据的关联。Lowactivation Ferritic/Martensitic steels are a kind of important structural materials candidate to the application in advanced nuclear energy systems. Possible degradation of properties and even failure in the condition of hightemperature and high helium production due to energetic neutron irradiation in a fusion reactor is a major concern with the application of this kind of materials. In the present work microstructural evolution in a 9Cr Ferritic/Martensitic steel (T92B) irradiated with 122 MeV 20Ne ions at temperatures between 0.3—0.5 Tm (Tm is the melting point of the material) was investigated with transmission electron microscopy. High concentration voids were observed in the specimens irradiated at high temperatures when the displacement damage dose and Ne concentration exceed a certain level. Preferential formation of voids at lathboundaries and other grainboundaries was found. The data of void swellings in 9Cr ferritic/martensitic steels irradiated in different conditions (such as with Heions, Neions, Fe/He dual beams, fast neutrons, Niions etc.) were compiled and analyzed based on a classic model of helium bubble formation, and bubble to void transition.
2009, 26(1): 55-58.
doi: 10.11804/NuclPhysRev.26.01.055
摘要:
利用20 keV的He离子注入表面蒸镀了Au薄膜的尖晶石（MgAl2O4）样品， 随后对注入样品进行了退火处理。 在紫外可见光谱上观察到了由于金属纳米颗粒的存在而引起的较强的表面等离子体共振吸收峰， 提供了材料中金属纳米颗粒形成的光谱证据。 并对形成的Au纳米颗粒的尺寸随退火温度以及He注入剂量的变化进行了研究。
Spinel deposited with a thin Au film was implanted with helium ions, and annealed in vacuum condition subsequently. The surface Plasmon resonance absorbance peak due to the existence of metallic nanoparticles in the dielectric matrix was observed on the UltravioletVisible Spectrometry, indicating the formation of metallic nanoparticles in spinel. The dependence of Au particles size with annealing temperature and implantation doses was also investigated.
利用20 keV的He离子注入表面蒸镀了Au薄膜的尖晶石（MgAl2O4）样品， 随后对注入样品进行了退火处理。 在紫外可见光谱上观察到了由于金属纳米颗粒的存在而引起的较强的表面等离子体共振吸收峰， 提供了材料中金属纳米颗粒形成的光谱证据。 并对形成的Au纳米颗粒的尺寸随退火温度以及He注入剂量的变化进行了研究。
Spinel deposited with a thin Au film was implanted with helium ions, and annealed in vacuum condition subsequently. The surface Plasmon resonance absorbance peak due to the existence of metallic nanoparticles in the dielectric matrix was observed on the UltravioletVisible Spectrometry, indicating the formation of metallic nanoparticles in spinel. The dependence of Au particles size with annealing temperature and implantation doses was also investigated.
2009, 26(1): 59-63.
doi: 10.11804/NuclPhysRev.26.01.059
摘要:
运用密度泛函理论研究了钒(Vanadium)在高压下的结构相变。 通过对体心立方(bcc)结构的钒在不同压强下剪切弹性系数C44的计算， 发现当压强约95 GPa时 C44＜0， 说明体心立方结构的钒在此条件下是不稳定的。 进一步计算分析得到钒在高压下发生了从体心立方到菱面体 (Rhombohedral)的结构相变， 相变压强约70 GPa， 这一结果与最近的实验结果符合。 还首次发现当压强约380 GPa时， 将会发生菱面体到体心立方的结构相变， 这有待实验的验证。
We have studied the structure phase transition of Vanadium under high pressures by density function theory. A mechanical instability in the shear elastic constant (C44) has been found for bodycentred cubic(bcc) Vanadium at about 95 GPa, which indicates the existence of the structural transition. By calculation and analysis, we found that there was a bccrhombohedral structure transition at the 70 GPa, which is consistent with the experiment data. Our calculations also firstly gave that there was a rhombohedralbcc structure transition at about 380 GPa, which needs to be verified by the experiment.
运用密度泛函理论研究了钒(Vanadium)在高压下的结构相变。 通过对体心立方(bcc)结构的钒在不同压强下剪切弹性系数C44的计算， 发现当压强约95 GPa时 C44＜0， 说明体心立方结构的钒在此条件下是不稳定的。 进一步计算分析得到钒在高压下发生了从体心立方到菱面体 (Rhombohedral)的结构相变， 相变压强约70 GPa， 这一结果与最近的实验结果符合。 还首次发现当压强约380 GPa时， 将会发生菱面体到体心立方的结构相变， 这有待实验的验证。
We have studied the structure phase transition of Vanadium under high pressures by density function theory. A mechanical instability in the shear elastic constant (C44) has been found for bodycentred cubic(bcc) Vanadium at about 95 GPa, which indicates the existence of the structural transition. By calculation and analysis, we found that there was a bccrhombohedral structure transition at the 70 GPa, which is consistent with the experiment data. Our calculations also firstly gave that there was a rhombohedralbcc structure transition at about 380 GPa, which needs to be verified by the experiment.
2009, 26(1): 64-68.
doi: 10.11804/NuclPhysRev.26.01.064
摘要:
利用上升气流模型模拟研究了地下玻璃固化体中As， Cs和Sr元素的迁移行为。 利用中子活化分析（INAA）技术检测了玻璃固化体中元素迁出量， 用原子力显微镜观察了迁出物质的形态。 实验结果表明： 在上升气流作用下， 被玻璃固化的元素会以纳米微粒的形式迁移出来， 迁移方向是垂直向上的， 迁出的元素会在玻璃固化体上方的吸附物中不断积累； 上升气流作用时间越长， 固化体中元素迁出的量越大； 玻璃固化体处置点与地表的温差越大， 元素迁出的速度越快。
The transporting behavior of As, Cs, Sr in vitrification form has been studied using a simulating model of ascending flows.Instrumental Neutron Activation Analysis (INAA) was used to determine the quantity of elements transportation. The results of simulating experiment show that the elements can be transported vertically from the vitrification form by ascending flows in the form of nanoscale particles. Then these elements accumulate continuously in the adsorber above the vitrification form. In addition, when the temperature difference between the ground surface and the environment where the vitrification form disposed increases, the transportation speed of these elements will increase too.
利用上升气流模型模拟研究了地下玻璃固化体中As， Cs和Sr元素的迁移行为。 利用中子活化分析（INAA）技术检测了玻璃固化体中元素迁出量， 用原子力显微镜观察了迁出物质的形态。 实验结果表明： 在上升气流作用下， 被玻璃固化的元素会以纳米微粒的形式迁移出来， 迁移方向是垂直向上的， 迁出的元素会在玻璃固化体上方的吸附物中不断积累； 上升气流作用时间越长， 固化体中元素迁出的量越大； 玻璃固化体处置点与地表的温差越大， 元素迁出的速度越快。
The transporting behavior of As, Cs, Sr in vitrification form has been studied using a simulating model of ascending flows.Instrumental Neutron Activation Analysis (INAA) was used to determine the quantity of elements transportation. The results of simulating experiment show that the elements can be transported vertically from the vitrification form by ascending flows in the form of nanoscale particles. Then these elements accumulate continuously in the adsorber above the vitrification form. In addition, when the temperature difference between the ground surface and the environment where the vitrification form disposed increases, the transportation speed of these elements will increase too.
2009, 26(1): 69-75.
doi: 10.11804/NuclPhysRev.26.01.069
摘要:
针对深部肿瘤重离子治疗临床试验的需求，首先在水介质中进行生物有效剂量的优化计算，然后根据CT图像中像素CT值与水等效长度转换系数之间的关系， 结合水中的深度剂量分布曲线对每个像素进行积分得到CT图像上的生物有效剂量分布。同时介绍了基于被动式束流配送系统适形照射时的剂量确定方式， 并提出二维适形放疗也应使用分层照射方式以适应治疗时的不同要求。 这些方法适合目前及今后在IMP进行的重离子治癌临床试验研究中治疗计划系统的需要。Basic algorithms of biological effective dose optimization and dose distribution on CT image for the heavy ion therapy project at the Institute of Modern Physics (IMP)， Chinese Academy of Sciences (CAS) are reported in this paper. Firstly， biological effective dose optimization is conducted in water. According to the relationship between CT number and water equivalent path length， an integral algorithm is used to calculate the average dose within a pixel and then the dose distribution in tissue is derived. Secondly， the dose determination of layerstacking conformal irradiation is described and the layerstacking method is proposed to be applied in twodimensional conformal irradiation. These methods are sufficient to the requirements of the ongoing and future heavyion clinical trials conducted at IMP.
针对深部肿瘤重离子治疗临床试验的需求，首先在水介质中进行生物有效剂量的优化计算，然后根据CT图像中像素CT值与水等效长度转换系数之间的关系， 结合水中的深度剂量分布曲线对每个像素进行积分得到CT图像上的生物有效剂量分布。同时介绍了基于被动式束流配送系统适形照射时的剂量确定方式， 并提出二维适形放疗也应使用分层照射方式以适应治疗时的不同要求。 这些方法适合目前及今后在IMP进行的重离子治癌临床试验研究中治疗计划系统的需要。Basic algorithms of biological effective dose optimization and dose distribution on CT image for the heavy ion therapy project at the Institute of Modern Physics (IMP)， Chinese Academy of Sciences (CAS) are reported in this paper. Firstly， biological effective dose optimization is conducted in water. According to the relationship between CT number and water equivalent path length， an integral algorithm is used to calculate the average dose within a pixel and then the dose distribution in tissue is derived. Secondly， the dose determination of layerstacking conformal irradiation is described and the layerstacking method is proposed to be applied in twodimensional conformal irradiation. These methods are sufficient to the requirements of the ongoing and future heavyion clinical trials conducted at IMP.
2009, 26(1): 76-79.
doi: 10.11804/NuclPhysRev.26.01.076
摘要:
利用激光扫描共聚焦显微技术和碱性单细胞凝胶电泳技术对经过离子注入后的黑松花粉粒内细胞核的直接损伤效应进行了观察鉴定。 研究结果表明， 离子注入后可以直接损伤细胞核结构， 导致细胞核裂解。 细胞核的损伤程度与注入离子的剂量密切相关， 即细胞核DNA分子的损伤程度随着注入离子剂量的增加而提高。 The damage of pollen nuclei of Pinus thunbergii induced directly by ion implantation were measured by the laser confocal microscopy technique and the singlecell gel electrophoresis test. The results showed that ion implantation caused the nuclei structure to be damaged， leading to the nuclei degradation. The results of statistical analysis showed that the damage grade of nuclei was very correlative with the ion dosage. The damage degree of DNA in the nuclei at the level of single cells was increased with the increase of the ion implantation dose.
利用激光扫描共聚焦显微技术和碱性单细胞凝胶电泳技术对经过离子注入后的黑松花粉粒内细胞核的直接损伤效应进行了观察鉴定。 研究结果表明， 离子注入后可以直接损伤细胞核结构， 导致细胞核裂解。 细胞核的损伤程度与注入离子的剂量密切相关， 即细胞核DNA分子的损伤程度随着注入离子剂量的增加而提高。 The damage of pollen nuclei of Pinus thunbergii induced directly by ion implantation were measured by the laser confocal microscopy technique and the singlecell gel electrophoresis test. The results showed that ion implantation caused the nuclei structure to be damaged， leading to the nuclei degradation. The results of statistical analysis showed that the damage grade of nuclei was very correlative with the ion dosage. The damage degree of DNA in the nuclei at the level of single cells was increased with the increase of the ion implantation dose.
2009, 26(1): 80-83.
doi: 10.11804/NuclPhysRev.26.01.080
摘要:
在中国科学院近代物理研究所自行研制的大功率电子加速器上， 研究了不同辐照剂量的电子束对大肠杆菌、 金黄色葡萄球菌和变形杆菌3种微生物的杀灭效果， 同时检测了辐照后菌体超氧化物歧化酶（SOD）活性的变化。 结果显示： 辐照剂量达到2.0 kGy时， 可完全杀灭金黄色葡萄球菌， 2.2 kGy时可完全杀灭大肠杆菌和变形杆菌; 辐照对3种微生物的SOD活性有较显著的影响。
To study the effects of radiation sterilization of the electron beam， the three species of microorganisms， Escherichia. coli， Staphylococcus aureus and Proteus vulgaris were irradiated with the electron beam, delivered by the electron accelerator independently developed by the Institute of Modern Physics， Chinese Academy of Sciences， and the changes of superoxide dismutase (SOD) activity of these irradiated microorganisms were also tested. The results indicated that the Staphylococcus aureus were fully radiosterilized with the radiation dosage of 2.0 kGy, but 2.2 kGy to the Escherichia.coli and Proteus vulgaris. Moreover， the data also demonstrated that the irradiation had noticeable effects on the SOD activity of the three microorganisms.
在中国科学院近代物理研究所自行研制的大功率电子加速器上， 研究了不同辐照剂量的电子束对大肠杆菌、 金黄色葡萄球菌和变形杆菌3种微生物的杀灭效果， 同时检测了辐照后菌体超氧化物歧化酶（SOD）活性的变化。 结果显示： 辐照剂量达到2.0 kGy时， 可完全杀灭金黄色葡萄球菌， 2.2 kGy时可完全杀灭大肠杆菌和变形杆菌; 辐照对3种微生物的SOD活性有较显著的影响。
To study the effects of radiation sterilization of the electron beam， the three species of microorganisms， Escherichia. coli， Staphylococcus aureus and Proteus vulgaris were irradiated with the electron beam, delivered by the electron accelerator independently developed by the Institute of Modern Physics， Chinese Academy of Sciences， and the changes of superoxide dismutase (SOD) activity of these irradiated microorganisms were also tested. The results indicated that the Staphylococcus aureus were fully radiosterilized with the radiation dosage of 2.0 kGy, but 2.2 kGy to the Escherichia.coli and Proteus vulgaris. Moreover， the data also demonstrated that the irradiation had noticeable effects on the SOD activity of the three microorganisms.
甘公网安备 62010202000723号