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In commissioning the HIRFL-CSR (Cooler Storage Ring of Heavy Ion Research Facility in Lanzhou),with the spectrum analyzer monitoring the beams on-line, we measured many parameters of the beam status for improving quality of the heavy ion beams. In this paper, the sudden change of the beam center frequency is analyzed.A theoretical analysis is done mainly on instabilities of the electron voltage and the neutralization factor. Simulations were made for the problem. According to the simulation result, we can conclude that it is the instability of neutralization factor that caused the problem. 中文摘要:HIRFL-CSR调试过程中,利用频谱分析仪实时监测束流,根据其上测的数据进行相关参数调整,改善束流的品质。本文对分析仪上观测到的现象一束流的中心频率发生突变进行了研究,主要就电子束的高压不稳定性和中性化因子的突变做了理论分析,并进行了相关的模拟计算 ,根据模拟结果初步断定该现象的出现由电子束的中性化因子导致。

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介绍了一种基于TMS320C6713和FPGA的数字电源控制模块,给出了模块的硬件组成和软件设计。该模块作为一种通用的控制平台,可以根据现场需要来设置相应的参数,实现直流/脉冲电源的控制。测试表明该模块有很高的控制精度,处理能力强,便于网络控制。

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以人类肝癌细胞SMMC-7721和正常肝细胞L02为研究对象,以这两种细胞0.3 Gy时超敏感性的存活数据为基础,从理论上探讨了γ射线照射时,用超分次技术治疗肝癌的可能性。经过计算发现:如果目标肿瘤和周围的正常组织超敏感性的存活差异提高到3%,即可利用超分次技术对肿瘤进行治疗。应用超分次进行分次照射时,照射的结果与分次的间隔时间有关。对这一现象的机理进行了一定的探讨,发现时间间隔与细胞G2期的长短可能存在一定的相关性。

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In order to investigate the biological effects of heavy ion radiation at low closes and the different radiosensitivities of growing and non-growing plants. rice at different lift stages (dry seed, wet seed and seedling) were exposed to carbon ions at closes of 0 02, 0.2, 2 and 20 Gy. Radiobiological effects on survival, root growth and mitotic activity, as well as the induction of chromosome aberrations in root meristem. were observed The results show that radiation exposure induces a stimulatory response at lower close and an inhibitory response at higher dose on the mitotic activity of wet seeds and seedlings Cytogenetic damages are induced in both seeds and seedlings by carbon ion radiation at doses as low as 0.02 Gy Compared with seedlings. seeds are more resistant to the lethal damage and the growth rate damage by high doses of carbon ions, but are more sensitive to cytogenetic damage by low closes of irradiation Different types of radiation induced chromosome aberrations are observed between seeds and seedlings. Based on these results, the relationships between low close heavy ion-induced biological effects and the biological materials are discussed.

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Isoscaling is derived within a recently proposed modified Fisher model where the free energy near the critical point is described by the Landau O(m(6)) theory. In this model m = N-f-Z(f)/A(f) is the order parameter, a consequence of (one of) the symmetries of the nuclear Hamiltonian. Within this framework we show that isoscaling depends mainly on this order parameter through the 'external (conjugate) field' H. The external field is just given by the difference in chemical potentials of the neutrons and protons of the two sources. To distinguish from previously employed isoscaling relationships, this approach is dubbed: m-scaling. We discuss the relationship between this framework and the standard isoscaling formalism and point out some substantial differences in interpretation of experimental results which might result. These should be investigated further both theoretically and experimentally. (C) 2010 Elsevier B.V. All rights reserved.

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RAPD(随机放大多态性DNA)是1种新的DNA分子标记技术。与RFLp、AFLP及ARDRA相比,RAPD具有可在一次试验中同时观察到大量的DNA多态性片段,方法更具简单、敏感、花费少等优点。阐述了RAPD的原理方法,及目前在微生物分类鉴定研究中的应用,并分析了RAPD技术在共生固氮放线菌Frankia分类鉴定及系统发育研究中的应用前景。

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