不同LET碳离子束辐照拟南芥干种子的当代损伤效应

本研究以拟南芥（Columbia野生型）干种子为材料,利用兰州重离子研究装置（HIRFL）产生的碳离子束对材料进行辐射处理,统计其存活率、根长、下胚轴长及每果荚种子数,以探讨不同传能线密度（Linear Energy Transfer,LET）的碳离子束辐照对拟南芥当代损伤效应的影响。结果表明,在相同LET辐射条件下,随着辐射剂量的增大,拟南芥的存活率、根长、下胚轴长度、每果荚种子数都呈现下降趋势。在相同剂量不同LET辐射处理情况下,随着LET的增大,存活率、根长、下胚轴长、每果荚种子数都显著下降,可见高LET辐射严重抑制了拟南芥的生长和发育。研究表明,当LET为50 keV/μm时,碳离子束辐射拟南芥干种子对应的最佳诱变剂量为200 Gy,为后续开展碳离子束辐射的诱变效率研究奠定了前期基础。Aimed to study the biological effects of carbon ion beams with different linear energy transfer (LET) values provided by Heavy Ion Research Facility in Lanzhou (HIRFL), dry seeds of Arabidopsis thaliana (Columbia-WT) were irradiated and a series of biological effects of postembryonic development, such as survival rate, primary root length, hypocotyls length and number of seeds per silique, were investigated. The results showed that, under the radiation condition of the same LET value, the survival rate, root length, hypocotyls length and number of seeds per silique were decreased with the increasing dose. In addition, under the radiation conditions with different LET values, but same dose, the extent of the decline of the survival rate, root length, hypocotyls length and number of seeds per silique were reinforced with the increasing LET. It was also found that high LET radiations inhibited the subsequent growth and development of Arabidopsis thaliana severely. In brief, it was suggested that the optimum dose of carbon ion beam with 50 keV/μm value on Arabidopsis thaliana dry seeds was 200 Gy. This research complemented the preliminary theoretical foundation for the comparative study of the highest mutation efficiency of carbon ion beam irradiations at IMP, CAS(Institute of Modern Physics, Chinese Academy of Sciences).     

Physical Properties of III-Antiminodes -- a First Principles Study

A comprehensive first principles study of III-Antimonide binary compounds is hardly found in literature. We report a broad study of structural and electronic properties of boron antimonide （BSb）, aluminium antimonide （AlSb）, gallium antimonide （GaSb） and indium antimonide （InSb） in zineblende phase based on density functional theory （DFT）. Our calculations are based on Full-PotentiM Lineaxized Augmented Plane wave plus local orbitals （FP- L（APWq-lo）） method. Different forms of exchange-correlation energy functional and corresponding potential are employed for structural and electronic properties. Our computed results for lattice parameters, bulk moduli, their pressure derivatives, and cohesive energy are consistent with the available experimental data. Boron antimonide is found to be the hardest compound of this group. For band structure calculations, in addition to LDA and GGA, we used GGA-EV, an approximation employed by Engel and Vosko. The band gap results with GGA-EV are of significant improvement over the earlier work.     

重离子束治癌

本文回顾了辐射治癌的历史发展和国内外动态,讨论了重离子束与常规辐射相比在肿瘤治疗上的优势,提出了为治疗应用的重离子束的主要参数以及在兰州重离子研究装置（ＨＩＲＦＬ）拟建的冷却储存环（ＣＳＲ）上建立治疗实验室的初步考虑． Historical background and trends at home and abroad for radiation therapy arelooked back in the paper. The advantages of heavy ion beam in comparision with conventional radiation in tumour treatment are discussed. The main parameters of heavy ion beams fortherapy application and a tentative idea constructing treatment rooms at Cooling StorageRing(CSR) of Heavy Ion Research Facility in Lanzhou (HIRFL) are proposed.     

辐射诱发体内旁效应特征的研究进展

大量的细胞生物学研究显示, 辐射诱发旁效应的传输信号包括活性氧自由基（ROS）、 一氧化氮自由基（NO）以及一些细胞因子。 近年来,越来越多的文献报道关于体内旁效应特征的研究, 并已经证实在生物体内辐射诱导的旁效应不仅能发生在相邻组织, 还可发生在远源器官。这些体内旁效应包括DNA损伤、表观遗传学改变、miRNA及基因表达改变、 细胞增殖和凋亡等。 为了总结和分析辐射诱发体内旁效应的特征, 本文综述了辐射诱发体内旁效应的特点, 包括其与性别、 传播途径、辐射品质的关系以及相关机制的研究。 Radiation induced bystander effect is defined as the induction of damage in neighboring non hit cells by signals released from directly irradiated cells. ROS, NO and cytokines are involved in signaling pathways of bystander effects. Recently, the bystander effects in vivo have been reported more and more. It has been indicated that radiation induced bystander effect was localized not only in bystander tissues but also in distant organs. This effect includes many biological endpoints such as DNA damage, epigenetic, miRNA and gene expression changes, cell proliferation and apoptosis. In this review we described different aspects of ionizing radiation induced bystander effects such as its characteristics, sex specific, signaling transfer, dose and LET dependence, and related mechanisms.     

利用高能离子模拟研究反应堆结构材料中的辐照效应

简要介绍了载能粒子辐射损伤对反应堆结构材料性能的影响,阐述了载能粒子束特别是高能离子束开展模拟研究的优势,并举例说明了国内利用高能重离子模拟研究反应堆结构材料辐射效应取得的进展。实验结果和理论分析表明,载能离子特别是高能离子辐照非常适合用于模拟研究反应堆结构材料中由粒子辐射引起的材料微观结构和宏观性能变化,是模拟研究反应堆结构材料辐射效应的非常有效的手段。 Radiation damage in structural materials of fission/fusion reactors is mainly attributed to the evolution of intensive atom displacement damage induced by energetic particles （ n, α and/or fission fragments） and highrate helium doping by direct α particle bombardments and/or （n, α） reactions. It can cause severe degradation of reactor structural materials such as surface blistering, bulk void swelling, deformation, fatigue, embrittlement, stress erosion corrosion and so on that will significantly affect the operation safety of reactors. However, up to now, behavior of structural materials at the end of their service can hardly be fully tested in a real reactor. In the present paper, damage process in reactor structural materials is briefly introduced, then the advantages of energetic ion implantation/irradiation especially high-energy heavy ion irradiation are discussed, and several typical examples on simulation of radiation effects in reactor candidate structural materials using high-energy heavy ion irradiations are introduced. Experimental results and theoretical analysis suggested that irradiation with energetic particles especially high-energy heavy ions is a very useful technique for simulating the evolution of microstructures and macro-properties of reactor structural materials.     

低能N+ 离子预处理对水稻UV-B辐射的当代损伤效应的影响

采用3种不同注量的N离子对供试材料进行了离子注入预处理, 再用10.08 kJ/(m2d1)增强UV-B辐射对其幼苗进行辐照试验, 测定了过氧化物酶（POD）活性、 过氧化物歧化酶（SOD）活性、 过氧化氢酶（CAT）活性、 丙二醛（MDA）含量、 还原型谷胱甘肽（GSH）含量和可溶性糖含量的变化。 研究结果表明: 经N离子注入预处理的水稻材料受到UV-B辐射时其POD和SOD活性明显升高, 并在注量为2.0×1017 ions/cm2时活性达到最强; CAT活性和MDA含量明显降低, GSH含量显著增加, 而可溶性糖的含量则变化程度很小。 从这些研究结果可以看出, 经过一定注量离子注入预处理的水稻材料当受到UV B辐射时能产生较强的抗氧化能力和防御能力,而且抗氧化系统优于碳水化合物系统而先于表达。 由此可见, 离子注入预处理对水稻UV-B辐射的生物学效应的影响相当明显。 The seedlings of rice (xindao18) were exposed to UV B (10.08 kJ/(m2d1 )) irradiation follo wing the pretreatment with three different implantation dosages of low energy N+ ions. Changes in the levels of the superoxide (POD),superoxide dismutase (SOD),catalase (CAT), malondialdehyde (MDA),glutathione (GSH) and soluble sugar were measured. The result showed that the UV-B irradiation on the seedlings of rice pretreated with low energy ions implantation could lead to increase activities in POD and SOD,and the maximum appeared on the dose of 2.0×1017 ions/cm2. Meanwhile,it made the content of GSH increased, and caused the activity of CAT and the content of MDA to be decreased. But there was no obvious change in soluble sugar. It was suggested that the rice pretreated by low energy ion implantation could enhance the antioxidation capacity and defensive ability when irradiated by UV-B, and the antioxidation system could be induced earlier than carbohydrate system. Therefore, the biological effects of UV-B irradiation on rice pretreated by low energy ion implantation were quite obvious.     

微生物碳捕获电池阴极室CO2捕获速率的计算

本文对含有Botryococcus Braunii UTEX 572的微生物碳捕获电池阴极室内的光合有效辐射（Photosyntheticallyactive radiation,PAR）分布建立数学模型。采用离散坐标法（Discrete Ordinate Method,DOM）求解一维稳态辐射传递方程（Radiative transfer equation.RTE）,使用SMARTS（the Simple Model for Atmospheric Transmission of Sunshine）模式对边界条件进行计算。在所建模型基础上,对400～800 nm波长范围的阴极室内PAR分布情况进行计算,并结合Botry-ococcusBraunii UTEX 572的生长动力学对CO₂的局部吸收速率进行研究。同时对不同散射处理方法,气泡含量以及藻类浓度对CO₂捕获速率的影响进行对比,为改善光在微生物碳捕获燃料电池阴极室的分布和阴极室优化设计提供依据。     

诺贝尔物理学奖百年回顾(续)

 （续前期）１９１１年维恩（ＷｉｌｈｅｌｍＣａｒｌＷｅｒｎｅｒＯｔｔｏＦｒｉｔｚＦｒｎａｚＷｉｅｎ１８６４－１９２８）因发现热辐射规律──维恩位移定律,建立黑体辐射的维恩公式,获得了１９１１年度诺贝尔物理学奖．１９世纪末,人们已经认识到热辐射和光辐射都是电磁波,并对辐射能量在不同频率范围内的分布问题,特别是黑体辐射,进行了较深入的理论和实验研究．维恩和拉梅尔（Ｏ．Ｌｕｍｍｅｒ）发明了第一个实用黑体──空腔发射作,为他们的实验研究提供了所需的“完全辐射”。维恩在前人研究的基础上于１８９３年提出了理想黑体辐射的位移定律：λｍａｘＴ＝常数。该定律指出,随着温度（Ｔ）的升高,与辐射能量     

大分割碳离子放射治疗中相对生物学效应与剂量依赖关系的研究

应用碳离子束进行大分割放射治疗从而缩短治疗周期是碳离子束治疗的优势之一。为研究大分割放疗增加单次照射剂量后,碳离子束相对生物学效应（RBE）的变化,应用细胞存活线性平方（LQ）模型推导出RBE与剂量的依赖关系。基于此关系研究了具有不同辐射敏感性的肿瘤细胞和正常组织细胞RBE随剂量的变化。结果表明,在0~20 Gy范围内,不论肿瘤细胞与正常组织细胞具有怎样的辐射敏感性,肿瘤细胞的RBE值始终大于正常组织细胞。此外,基于理论推导和对相关实验数据的分析,证实了RBE随剂量增加而递增现象的存在。这些结果对应用碳离子束进行大分割放射治疗具有重要的指导作用。Short treatment course due to the suitability of hypofractionated regimen for carbon ion beam is one of the advantages of carbon ion radiotherapy. To study the dependence of relative biological effectiveness (RBE) on dose, the relationship between RBE and dose was deduced through the linear-quadratic (LQ) model. Based on the relationship, the change of RBE of tumor cells and normal tissue cells with different radiosensitivities with dose was studied. The results showed that the RBE value of tumor cells was always greater than that of normal tissue cells in the dose range of 0~20 Gy, regardless of the radiosensitivity of tumor and normal tissue cells. In addition, based on theoretical deduction and analysis of the relevant experimental data, the existence of RBE increase with increasing dose was verified. These results are of great significance for conducting hypofractionated radiotherapy with carbon ion beam.     

类氢U91+离子的辐射复合及其辐射退激发过程的理论研究

基于多组态Dirac-Fock理论方法,利用GRASP92和RATIP以及在此基础上最新发展的RERR06程序,对类氢U⁹¹⁺（1s）离子的辐射复合截面以及辐射退激发过程进行了详细的理论研究.系统地计算了具有确定能量的连续电子被处于基态的类氢U⁹¹⁺（1s）离子俘获到nl （1≤n≤8, 0≤l≤6）轨道形成类氦U⁹⁰⁺（1snl）离子的辐射复合截面,并研究了这辐射复合末态退激发谱的相对强度.研究发现,类氢U⁹¹⁺（1s）离子辐射复合到不同轨道的截面随其主量子数的增大而显著减小;同时,辐射复合末态的退激发对Kα谱线的相对强度有重要影响. 关键词： 辐射复合 多组态Dirac-Fock理论方法 辐射退激发     

激光的发明和发展

激光（LASER）是受激而发射的光，是“光受激辐射放大”的简称，它的含义是通过辐射的受激发射而实现光的放大（Light Amplification by Stimulated Emission of Radiation）．产生激光的器件叫做激光器,激光是一种强烈的、集中的、高度平行的相干光束．激光（1960年由美国人Maiman发明）、晶体管（1948年由Bardeen和Brattain发明）与原子能反应堆（1942年由意大利人Fermi发明）被人们视为20世纪最重要的三大技术发明，对现代科学技术的发展产生了深远影响.     

面向空间高能重离子与辐射屏蔽材料的反应截面地基研究

空间辐射尤其是高能重离子辐射可造成生物机体的严重损伤, 所以对高能重离子进行恰当的辐射屏蔽, 成为实现载人航天的关键性因素之一。 研究表明, 由于高能重离子与不同屏蔽材料发生相互作用, 所产生的核碎片等次级粒子, 直接影响空间辐射屏蔽材料的屏蔽性能研究和屏蔽结构设计。 介绍了太空辐射的分类与组成, 综述了国际地基辐射屏蔽材料与实验现状。 根据文献中的地基实验数据, 重点描述了被动式屏蔽方法: 以相近能量多种重离子, 不同能量的56Fe和28Si重离子分别与C, H, Al和Cu材料相互作用的总反应截面和碎片产生截面, 并结合510 MeV/u 56Fe与不同厚度CH2相互作用产生的碎片通量分布、 碎片平均LET分布和不同厚度CH2的单位入射离子剂量减少量等方面, 系统讨论分析了C, H, Al, Cu和CH2等常用空间辐射屏蔽材料的屏蔽性能。 Cosmic radiation, particularly the high energy heavy ion radiation, may cause serious injury on living organism. Therefore, it is one of critical restriction factor in Manned Spaceflight. Studies show that high energy heavy ions interacting with the shielding materials can produce numerous kinds of fragments and secondaries. These particles have a direct impact on evaluation of shielding properties of different shielding materials, the optimal shielding structure design and low dose evaluation after shielding materials. From perspectives of divisions of cosmic rays and passive shielding methods, this paper introduces the ground based research of shielding materials. The passive shielding method was discussed, based on the experimental data of the total cross sections and fragment（production） cross sections of the aspects of different heavy ions with approximately same energy and 56Fe, 28Si heavy ions with different energies on H, C, CH2, Al and Cu radiation shielding materials. In addition, the fragment fluency distribution, the average LET distribution and the dose reduction per particle of 510 MeV/u 56Fe in different depth of CH2 material were also discussed.     

聚四氟乙烯密封材料的电子束辐射效应研究

采用低能电子束辐射系统地研究了操作氚系统用密封材料（聚四氟乙烯）的辐射效应。利用扫描电镜和X光电子能谱仪分析了材料的表观形貌和表面元素的变化,用X射线粉末衍射仪和热分析仪分析了辐照前后材料的结晶度改变和热稳定性程度,并利用气相色谱仪和质谱仪测定了辐射降解气体的成分和生成量随吸收剂量的变化规律。采用电子自旋共振谱仪研究了材料在辐照过程中产生的中间体（自由基）,利用正电子湮没寿命谱仪分析了材料中的自由体积孔洞及浓度。结果表明,辐照前聚四氟氟乙烯样品的表面是规则的带状晶形结构,经1×10^5Gy辐照后样品的晶状结构遭到了明显的破坏,向非晶态转变显著。辐照后样品的熔点和热分解温度均呈下降趋势,表明样品的热稳定性降低。聚。四氟乙烯材料在氧气气氛中发生的辐射降解最为严重,其次是真空,而在氘气气氛中辐射降解最少。材料的辐射降解主要发生在主链上,即C—C键断裂,而侧基C—F键的断裂相对较少。第三寿命强度I3的变化规律与τ3相反,即随吸收剂量的增大,第三寿命的强度I3降低,表明自由体积孔洞的浓度降低。 The radiation effect of polytetrafluoroethylene used as a kind of sealing material in the tritium system was studied by using electron beam. The superficial configuration and state were analyzed by SEM and XPS respectively, and the crystal degree and thermal stability were determined by XRD and DSC. At the same time the composition of gas products after radiation ,was measured by GC/MS, and the yield of CO2 with the dose increasing was analyzed. The free radicals produced in the process of radiation were studied by ESR, and the content of free volume of PTFE is analyzed by positron annihilation lifetime spectroscopy. The result is that the crystal structure of the sample irradiated at the dose of 1 × 10^5 Gy is of an obvious damage while the structure of the unirradiated sample is crystal band. The transformation of the sample which has high crystal degree amorphous one. The melting point and thermal ecomposition temperature trend sample＇s thermal stability drops. The radiation decomposition of the sample is is remarkable from crystal state to to decline, which indiccates that the mainly the rupture of C--C bond, and less is the rupture of C--F bond. The Intensity I3 of the third lifetime fails with increasing the absorbed dose, which demonstrates the reduction of free volume cave content. Compared with I3, the rule of τ3 is reverse.     

聚四氟乙烯的辐射效应及其ESR研究

该文回顾了从上世纪50年代中期至近年来人们在聚四氟乙烯（PTFE）辐射效应方面的研究工作,初步总结了辐射PTFE产生的自由基及其相应的过氧化自由基的电子自旋共振（ESR）波谱学应用研究,总结并讨论了实验温度、辐射剂量、PTFE粉末形式、结晶度和交联等因素对辐射PTFE自由基ESR信号的影响. 同时还简要介绍了辐射PTFE后的自由基反应以及辐射交联的进展情况.     

海洋气溶胶多角度偏振辐射特性研究

海洋气溶胶是对流层气溶胶的重要组成部分,对全球的辐射收支平衡及气侯变化均有重要的影响。评价气溶胶的直接与间接辐射效应需要对气溶胶的性质进行深入的研究。多角度偏振为气溶胶光学物理性质研究提供了新的方法。在对可见光550 nm和近红外860 nm波段处海洋气溶胶的光学性质的研究基础上,采用矢量辐射传输模型模拟了TOA（top of atmosphere）反射率和偏振反射率与下垫面性质、观测方位角、气溶胶光学厚度之间的敏感性。模拟结果表明,海洋型气溶胶的多角度偏振信息可以有效地体现气溶胶的光学性质,可以利用多角度偏振遥感信息进行海洋气溶胶的反演,为利用多角度偏振遥感数据进行海洋气溶胶提供了理论基础。     

一些XYZ共振态的辐射衰变

类粲偶素态Y（3940）,Z（3930）和X（4160）可由带粲数的矢量介子相互作用动力学地产生出来,它们的开粲辐射衰变对于理解其内部结构有重要意义。本文研究了这些共振态衰变到D＊Dγ或Ds＊Dsγ的开粲辐射衰变,结果表明,对分别具有D＊D＊（或Ds＊D s＊）分子态和非分子态结构的XYZ共振态,其辐射衰变宽度（或辐射衰变宽度比）相对于Dγ（或Dsγ）体系不变质量Minv的分布图存在非常明显的区别,这为鉴别类粲偶素态XYZ是否具有分子态结构提供了很好的理论判据。     

诺贝尔物理学奖百年回顾(续)

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宇宙质心参考系

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利用LBH辐射图像数据反演大气O/N2方法

利用极光Lyman-Birge-Hopfield (LBH) 辐射图像数据可用来研究太阳风磁场与地球磁场耦合、亚暴与磁暴等过程,综合LBH辐射图像数据和O原子135.6nm辐射数据可反演电离层氧原子与氮气分子O/N2比值分布,进而研究高层大气组分信息及电离层分布变化,对科学研究和空间天气预报具有重要意义. 本文给出了LBH辐射传输机理和我国自主研制的搭载在风云三号D星（FY-3D）上的广角极光成像仪（Wide-field Auroral Imager, WAI）在轨获得的LBH 140-180nm波段极光辐射图像数据. 结合大气紫外辐射积分代码（Atmospheric Ultraviolet Radiance Integrated Code, AURIC）计算O135.6nm辐射数据、LBH辐射光谱以及MSISE00大气模型计算的O、N2数据,给出了利用WAI观测的LBH辐射图像数据反演大气O/N2比值理论计算方法,该方法将为利用我国自主观测LBH辐射数据和O135.6nm辐射数据开展空间信息反演研究打下基础.     

周期极化非线性晶体中太赫兹波辐射研究

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