重离子辐射植物的诱变效应研究及应用

重离子生物技术已引起人们的广泛关注, 植物育种是重离子生物技术研究和应用的热点之一。 简要介绍了重离子的基本特征和在育种应用中的优势, 综述了重离子辐射对植物分子、 细胞、 个体3个水平的诱变效应研究及重离子辐射育种取得的进展。 Heavy ion biotechnology has received much attention since the mid 1980s, when the first mutagenic effect of heavy ion beams was found in rice. Since then, plant breeding is one of the focuses in heavy ion biotechnology. In this paper we outlined the recent developments in plant breeding by heavy ion beams. We introduced briefly the essential characteristics and superiority of heavy ion beams applied in plant breeding, and reviewed further the mutagenic research in three levels(e.g., molecular, cell and individual) of plants. At last, we summarized artificial mutants obtained in plants irradiated by heavy ion beams.     

重离子辐射权重因数与辐射损伤模型研究进展

以第五届国际重离子在生物医学中应用会议和第十届国际辐射研究大会为背景,讨论了重离子生物学效应因数、辐射损伤生物物理模型和物理参数的表征等问题． Based on the fifth workshop on heavy charged particles in biology and medicine and the 10 th international congress of radiation research,the biological effects of heavy ions and biophysical models of heavy ions are discussed.     

CSR能区重离子反应中的介子产生

重离子反应中介子产生的观测对于认识重离子反应动力学和核物质性质具有重要的意义 .讨论了重离子反应中阈能附近介子产生的一些特点和研究现状 ,特别讨论了π介子产生和K+ 介子产生 .在我国兰州重离子冷却储存环上开展这方面的实验研究具有可能性 ,可望得到很有意义的结果 .及时开展这方面实验研究和相应的理论研究是必要的.It is important to measure meson productions in heavy ion collisions in order to understand the dynamics of heavy ion reactions and the properties of nuclear matter. In this paper we review the characteristic and present status of meson productions near the threshold energies in heavy ion collisions. Especially the pion and K + productions are discussed. We point out that it is meaningful and possible to carry out the experimental studies at the CSR. It is necessary to carry out timely the...     

高功率激光在存储环上的应用

重离子冷却存储环中的束流是高密度的等离子体,这样的束流照射物体将得到超高压强．如果高功率激光照射束流,将产生实验室中从来没有过的超高温度．这些极端的条件为开辟重离子物理研家新领域提供了可能性．在存储环中使用X射线激光可以测显类锂离子的电荷均方根半径绝对值,使核基态性质的研究将有突破性的进展．它开辟了在等离子体物理、金属物理、核物理和天体物理等领域新的实验条件．为惯性聚变的快速点火创造了最好条件． In cooling storage ring heavy ion beam is plasma of high density. when a big power laser interacted on it, it will get ultra-high temperature. This beam irradiated on an object will get ultra-high pressure. This high energy pulse laser can produce X-ray laser. In the cooling storage ring absolute value of charge mean root radius of Lithium-like nuclei will be measured by the X-ray laser. It will be broken through in investigating the property of nuclear ground state. That will create many...     

利用HIRFL高能重离子束的核能材料辐照损伤研究

载能重离子与高能中子在材料中能够产生相似的级联碰撞损伤,加之重离子具有大的离位损伤截面和在材料样品中低的感生放射性,载能重离子束成为模拟先进核能装置内部结构材料辐照损伤的重要手段。HIRFL能区的重离子在结构材料中的射程一般远大于晶粒尺寸,因此能够产生材料体损伤,借助小样品技术可以获得材料力学性能变化（尤其辐照脆化）的有用信息,为探讨材料辐照损伤微结构和宏观力学性能变化的关联提供了重要条件。本文简要介绍了近年来我们基于HIRFL高能离子束开展的聚变堆候选材料辐照损伤的研究,包括低活化钢的辐照脆化行为、氧化物弥散强化（ODS）铁素体钢的结构优化对于抗辐照性能的影响、不同载能粒子辐照条件下铁素体/马氏体钢的辐照肿胀数据的关联,以及高能重离子辐照的钨材料中氢同位素的滞留行为。研究表明,结合特殊的测试技术及数据分析方法,高能重离子可作为核能结构材料辐照损伤研究及评估的有效手段。Because of the similarity in cascade damage structure in materials produced by energetic heavy ions and by fast neutrons, and the high displacement rate and low induced radioactivity of samples by heavy ions, heavy ion beam becomes an important tool to simulate radiation damage by energetic neutrons in materials in advanced nuclear energy systems. The ranges of heavy ions provided by HIRFL (Heavy Ion Research Facility in Lanzhou) are generally much larger than the mean dimensions of grains in alloys candidate to advanced nuclear reactors, and is capable of producing radiation damage in bulk scale. It therefore makes possible the evaluation of change of mechanical properties including the radiation induced embrittlement from the irradiated specimens by using miniaturized specimen techniques. In the present paper, we provide an introduction of our recent studies of radiation damage of materials candidate to future fusion reactors by utilizing heavy ion beams in HIRFL.The studies include issues as follows:ductility loss of RAFM steels causes by high-energy Ne ions, impact of oxide dispersoids on the radiation resistance of ODS ferritic steels, correlation of void swelling of ferritic/martensitic steels under different particle irradiation, and behavior of deuterium retention in tungsten under irradiation with high-energy heavy ions. The results show that high-energy heavy ions can be used as a tool to efficiently investigate or evaluate radiation damage in structure materials if combined with some special test techniques and data analysis.     

H2O分子在不同电荷态的重离子作用下的离化

利用含时密度泛函理论和局域密度近似方法，计算了H2O分子在速度为12．5α0／fs的重离子C^＋和C^2＋作用下产生的各种电荷态的H2O分子离子的几率、平均逃逸电子数和偶极矩的变化随时间的演化。计算结果表明，在重离子势最大时，电偶极矩的变化最大，重离子的电荷态越高，得到高电荷态H2O分子的几率越大；重离子远离分子时，电偶极矩的变化趋于平缓。The time-dependent density functional theory （TDDFT） and local density approximation （LDA） are used to calculate the dipole moment changes, the ionization probabilities of the H20 molecule and the time-dependent probabilities of escaped electrons in the process of excitation of H2O molecule by C^＋ , C^2＋ with energy of 2.3 MeV/u. It is shown that the dipole moment changes of H2O are the greatest and the higher the charge staate of heavy ion, the bigger the probabilities of the high charge state of H2O molecule at maximal heavy ion potential. The dipole moment changes slightly when heavy ion leaved far from molecule.     

聚合物材料的快重离子辐照效应

简要介绍了快重离子辐照损伤的特点,通过与低电离辐射粒子辐照在聚合物材料中产生的效应的类比论述了快重离子辐照在聚合物材料中产生的效应及其研究现状 ,并结合快重离子辐照效应的应用展望了该领域未来的发展.The irradiation effects in polymers induced by swift heavy ions were reviewed in comparison with that induced by low ionization particles based on the characteristics of swift heavy ion irradiations. It is shown that bond breaking and cross linking, gas releasing, amorphization and carbonization of polymers depend strongly on the electronic energy loss. Besides special effects such as alkynes production, can be induced under swift heavy ion irradiation. The perspectives...     

中能重离子碰撞动力学理论的新进展

简要评述当前几种主要的中能重离子碰撞动力学理论优缺点的基础上，介绍本小组初步建立起来的两体关联输运理论以及中能重离子碰撞中同位旋相关输运理论的进展情况． Based on the analyses of successes and shortcomings of Boltzmann type models and quantum molecular dynamics for heavy ion collisions, the new progress of two body correlation transport theory and isospin dependent transport models for heavy ion collision are proposed.      

重离子治癌的磁扫描照射野形成法

在论述重离子治癌照射的基本思想及其特点的基础上,着重对磁扫描照射野形成的两种技术路线——点扫描和栅扫描的优缺点进行了分析阐述.初步给出了 HIRFL上的重离子治癌终端磁扫描相关参数. The basic principle and characteristic of irradiation in heavy ion radiotherapy are introduced. Based on the basic principle and characteristic of irradiation in heavy ion radiotherapy, two magnetic scan methods for creating uniform irradiation field--the spot scan and the raster scan, are compared briefly. The parameter requests to the magnetic scanning system of the heavy ion radiotherapy facility planned in IMP(Institute of Modern Physics) are presented.     

Heavy flavor baryon spectra via QCD sum rules

In this talk, we give a short review of our recent works on studying the singly heavy baryon, doubly heavy baryon, and triply heavy baryon Spectra from QCD sum rules.     

重夸克等效理论和重味强子体系质量谱的研究

利用重夸克等数理论,对重味强子Qq、QQq和Qqq以及四夸克态QQqq的质量谱进行了系统定性的研究,并与势模型对QQqq的计算结果进行了比较.     

研究重元素原子谱学性质的可能性

论述了重元素,特别是超重元素原子谱学的重要意义。指出了对这些元素原子谱学进行研究的必要性。探讨了通过核反应产生重元素的几率和产额, 以及可能的收集方法,表明了这可为重元素原子谱学研究提供必要的条件。 同时也简单描述了研究重原子谱学的方法——激光共振电离法。 The importance of the atomic spectroscopy of heavy elements,especially the superheavy elements has been briefly reviewed. It is pointed that studies of the atomic spectroscopy of very heavy elements is necessary from the atomic physics and the identification of new superheavy elements. The production probability and yields of heavy elements in the heavy ion induced reactions were discussed. And the possible collection methods for heavy residue of reactions were also retrospected. Those techniques which have been used in the heavy ion reactions and superheavy element identifications will provide some possible support to the studies of heavy element spectroscopy.     

A diquark model for baryons containing one heavy quark

We present a phenomenological ansatz for coupling a heavy quark with two light quarks to form a heavy baryon. The heavy quark is treated in the heavy mass limit, and the light quark dynamics is approximated by propagating scalar and axial vector ??diquarks??. The resulting effective lagrangian, which incorporates heavy quark and chiral symmetry, describes interactions of heavy baryons with Goldstone bosons in the low energy region. As an application, the Isgur-Wise form factors are estimated.     

A diquark model for baryons containing one heavy quark

We present a phenomenological ansatz for coupling a heavy quark with two light quarks to form a heavy baryon. The heavy quark is treated in the heavy mass limit, and the light quark dynamics is approximated by propagating scalar and axial vector ‘diquarks’. The resulting effective lagrangian, which incorporates heavy quark and chiral symmetry, describes interactions of heavy baryons with Goldstone bosons in the low energy region. As an application, the Isgur-Wise form factors are estimated.     

起始相位的受限排列

在含重原子晶体结构的测定中,重原子贡献的相位是一个非常重要的信息。利用重原子相位作电子密度逼近或者Karle迭代是求解含重原子晶体结构的重要手段。但是,当重原子的贡献不占主导地位,或者当重原子分布的对称性高于整个结构的对称性时,上述方法就不易奏效。这时的重原子信息是否还可以用来大大简化结构分析的过程?这是一个值得探讨的问题。本文提出利用重原子的相位来限制直接法中起始相位的排列方式。这样可以成倍地缩减起始相位排列的种数。这一方法同作者提出的另一方法相配合可以使直接法在测定含重原子晶体结构方面的效能大为提高。 关键词：     

重原子信息在直接法中的应用——含重原子晶体结构因子相位的统计估算

重原子所提供的信息对测定含重原子晶体结构有重要的作用。如何利用重原子信息将影响到测定工作是否顺利乃至能否成功。本文提出一种利用重原子信息的新方法。这个方法能够更充分地利用重原子信息,并能使重原子法同直接法更有效地结合起来。 关键词：     

Disorder physics in mixtures of fermionic atoms

A mixture of light and heavy fermionic atoms in an optical lattice is considered. Tunneling of the heavy atoms is neglected such that they are only subject to thermal fluctuations. There is a complex interplay between light and heavy atoms which results in an Ising-like distribution of heavy atoms with a first-order transition from homogeneous to staggered order. A second-order transition is possible between an ordered and a disordered phase of heavy atoms. Depending on the phase of heavy atoms, light atoms are scattered around and can propagate, diffuse, and localize. Due to correlations in the disordered phase of heavy atoms, there can be a gap in the spectrum of light atoms, leading to a Mottlike incompressible state.     

Radiative decays of heavy baryons with heavy quark symmetry

The decay widths for the radiative decays of heavy baryons are calculated in the heavy quark effective theory. Introducing the interpolating fields for heavy baryons we obtain the transition matrix elements and the corresponding decay widths. Considering theSU(6) flavor-spin wave functions for heavy baryons, the coupling constants are calculated in the nonrelativistic quark model. Since the masses of the heavy baryons are not available, we have taken the predicted bag model masses. We find our results are quite different from that of the heavy quark bag model calculations.     

矿业废弃地重构土壤重金属含量高光谱反演

矿产资源对工业和国民经济的发展有重要的作用,但是随着矿业开采规模的扩大,资源枯竭、经营不善而形成的矿业废弃地越来越多。由于长时间受到采矿的影响,矿业废弃地土壤中存在大量的重金属元素,高浓度重金属可能会对环境和人体产生影响。土地复垦是整治污染、退化土壤再利用的重要方法,对重构后的土壤进行重金属含量检测是衡量土地复垦成效的重要指标,需要长期进行跟踪监测。传统的化学检测方法效率低、成本高、无法实现重金属大范围检测。高光谱是一种新兴的、发展潜力巨大的技术,在环境保护,资源利用,区域可持续发展等方面有着广泛的应用。经过近几十年的快速发展,仪器精度逐渐提高,检测方法逐渐成熟,为实现土壤重金属高效、便捷检测提供了可能。正常土壤重金属含量一般相对较低,采用光谱测量重金属含量较为困难,但铁矿开采区矿业废弃地由于土壤中的铁元素较多,会使土壤中的重金属的存在和聚集形式发生变化,影响重金属对光谱的响应,从而使土壤光谱反射率与重金属含量之间关系更加明显。以湖北省大冶市复垦矿区研究区,采样化学检测方法获取土壤重金属（As,Cr,Zn）含量;借助于美国ASD公司生产的FieldSpec4地物光谱仪（350～2 500 nm）获取土壤反射率,应用一阶微分、倒数对数、连续统去除法分别对反射率曲线进行预处理,提取出光谱特征波段,分析三种重金属元素与光谱特征间的相关性并建立逐步回归模型。研究表明,光谱数据预处理可使光谱特征波段更加明显,其中一阶微分和连续统去除法的效果最为明显。3种重金属元素的特征波段为495,545,675,995,1 425,1 505,1 935,2 165,2 205,2 275和2 355 nm。将土壤重金属含量与光谱特征波段之间做相关性分析,三种重金属都表现出了与光谱曲线的相关性,相关系数大部分都达到了0.5以上,最大相关系数为0.663,由于重金属种类和预处理方式的不同会导致相关性系数存在明显的差异。利用与土壤重金属相关性最大的特征波段建立三种重金属反演模型,并以反演模型r大小选择每种重金属的最优反演模型。由于重金属种类的不同,模型的选择也有差异,Cr和Zn一阶微分逐步回归为最佳反演模型,重金属As连续统去除法逐步回归为最佳反演模型。通过检验,三种重金属中Cr反演效果最好,RMSE为2.67,其次是Zn和As。对比当前不同检测手段可知,基于土样和光谱数据预处理的土壤重金属含量地物光谱仪高光谱反演是比较理想的。可为矿业废弃地土壤重金属高光谱反演提供参考。