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Plasma Science and Technology 2009年第6期11卷 744-749页

作者：庞敏姚建铭王冬梅 Key Laboratory of ion beam Bio-engineering of Institute of Plasma Physics Chinese Academy of Sciences Hefei Research Center of ion beam Engineering and Technology

Low energy ion beam has been widely applied in microbe breeding, plant breeding, gene transfer and cell modification. In this study, the Escherichia coli （***） strain producing tryptophanase was irradiated by a low energy nitrogen ion beam with an energy of 10 keV at a fluence of 13 × 10^14 N^＋/cm^2 when glycerin at a 15% concentration was used as a protector. The effect on the biomass of E. coli after N^＋ implantation was analyzed in detail by statistic methods. The screening methods used in this study were proven to be effective. After continuous mutagenicity, a high-yield tryptophanase strain was selected and both its biomass and enzymatic activity were higher than those of the parent strain. The results of scale-up production showed that the biomass could reach wet weight 8.2 g/L and 110 g L-tryptophan could be formed in the volume of the 1 l enzymatic reaction system.

关键词： ion implantation L-tryptophan Escherichia coli breeding

Electron beam density imaging system at beam study using a portable slit the Shanghai Electron ion Trap

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Chinese Physics B 2011年第8期20卷 136-142页

作者： Yang Yang Lu Di Pu Yun-Qing Yao Ke Chen Wei-Dong Xiao Jun Geng Zhi-Xian Roger Hutton Zou Ya-Ming The Key Laboratory of Applied ion beam Physics of Ministry of Education Shanghai 200433 China Shanghai Electron beam ion Trap Laboratory Institute of Modern Physics Fudan University Shanghai 200433 China

In this work, a portable slit imaging system is developed to study both the electron beam diameter and the profile of the newly developed Shanghai Electron beam ion Trap （Shanghai EBIT）. Images are detected by a charge coupled device （CCD） sensitive to both X rays and longer wavelength photons （up to visible）. Large scale ray tracings were conducted for correcting the image broadening effects caused by the finite slit width and the finite width of the CCD pixels. A numerical de-convolution method was developed to analyse and reconstruct the electron beam density distribution in the EBIT. As an example of the measured beam diameter and current density, the FWHM （full width at half maximum） diameter of the electron beam at 81 keV and 120 mA is found to be 76.2 μm and the density 2.00 × 10^3 ***-2, under a magnetic field of 3 T, including all corrections.

关键词： electron beam density slit imaging de-convolution

Optimization of L-lactic Acid Production of Rhizopus Oryzae Mutant RLC41-6 by ion beam Implantation at Low-Energy

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Plasma Science and Technology 2005年第5期7卷 3078-3080页

作者：周秀红葛春梅姚建铭潘仁瑞余增亮 Key Laboratory of ion beam Bioengineering Chinese Academy of Sciences

In order to obtain an industrial strain with a higher L（＋）-lactic acid yield, the strain Rhizopus oryzae RF3608 was mutated by means of nitrogen ion beam implantation and the mutant strain RLC41-6 was isolated. Under optimal conditions the yield of L（＋）-lactic acid produced in a shake-flask reached 133 g/L - 137 g/L after 36 h cultivation, indicating that the conversion rate based on glucose was as high as 88% - 91% and the productivity was 3.75 g/L.h. It was almost a 115% increase in lactic acid production compared with the original strain RF3608.

关键词： ion implantation fermentation L(+)-lactic acid Rhizopus oryzae

Effects of 13 T Static Magnetic Fields (SMF) in the Cell Cycle Distribution and Cell Viability in Immortalized Hamster Cells and Human Primary Fibroblasts Cells

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Plasma Science and Technology 2010年第1期12卷 123-128页

作者：赵国平陈少鹏赵烨朱玲燕黄佩鲍凌志王军王磊吴李君吴跃进许安 Key Laboratory of ion beam Bioengineering Institute of Plasma PhysicsChinese Academy of Sciences

Magnetic resonance image （MRI） systems with a much higher magnetic flux density were developed and applied for potential use in medical diagnostic. Recently, much attention has been paid to the biological effects of static, strong magnetic fields （SMF）. With the 13 T SMF facility in the Institute of Plasma Physics, Chinese Academy of Sciences, the present study focused on the cellular effects of the SMF with 13 T on the cell viability and the cell cycle distribution in immortalized hamster cells, such as human-hamster hybrid （AL） cells, Chinese hamster ovary （CHO） cells, DNA double-strand break repair deficient mutant （XRS-5） cells, and human primary skin fibroblasts （AG1522） cells. It was found that the exposure of 13 T SMF had less effect on the colony formation in either nonsynchronized or synchronized AL cells. Moreover, as compared to non-exposed groups, there were slight differences in the cell cycle distribution no matter in either synchronized or nonsynchronized immortalized hamster ceils after exposure to 13 T SMF. However, it should be noted that the percentage of exposed AG1522 cells at G0/G1 phase was decreased by 10% as compared to the controls. Our data indicated that although 13 T SMF had minimal effects in immortalized hamster cells, the cell cycle distribution was slightly modified by SMF in human primary fibroblasts.

关键词： static magnetic fields immortalized hamster cells human primary fibroblasts cells

Improving the uniformity of RF-plasma density by a humped variable-gap spiral antenna

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Chinese Physics B 2008年第11期17卷 4242-4246页

作者：徐旭李林森刘峰周前红梁荣庆 Applied ion beam Physics Laboratory Institute of Modern Physics Fudan University

This paper develops a humped spiral antenna of top inductively coupled plasma with variable gap. Comparing with planar spiral antennae, it investigates the performance of humped spiral antennae in the calculated electromagnetic configurations and experimental results. It finds that the humped antenna has the improved uniformity of plasma density in the radial direction and the decreased electron temperature in the top inductively coupled plasma. By experimental and theoretical analyses, the plasma performance in the case of humped antennae is considered to be the combined results of the uniform electromagnetic configurations and the depressed capacitively coupling effect.

关键词： inductively coupled plasma Langmuir probe planar antenna density uniformity

A Mutant of Bacillus Subtilis with High-Producing Surfactin by ion beam Implantation

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Plasma Science and Technology 2006年第4期8卷 491-496页

作者：刘清梅袁航王军贡国鸿周伟樊永红王丽姚建铭余增亮 Key Laboratory of ion beam Bioengineering Chinese Academy of SciencesHefei 230031China

In order to generate a mutant of Bacillus subtilis with enhanced surface activity through low energy nitrogen ion beam implantation, the effects of energy and dose of ions implanted were studied. The morphological changes in the bacteria were observed by scanning electron microscope （SEM）. The optimum condition of ions implantation, 20 keV of energy and 2.6 × 10^15N^＋/cm^2 in dose, was determined. A mutant, B.s-E-8 was obtained, whose surface activity of 50-fold and 100-fold diluted cell-free Landy medium was as 5.6-fold and 17.4-fold as the wild strain. The microbial growth and biosurfactant production of both the mutant and the wild strain were compared. After purified by ultrafiltration and SOURCE 15PHE, the biosurfactant was determined to be a complex of surfactin family through analysis of electrospray ionization mass spectrum （ESI/MS） and there was an interesting finding that after the ion beam implantation the intensities of the components were different from the wild type strain.

关键词： bacillus subtilis surfactin low energy ion beam implantation mutation breeding

The Mutation Breeding and Mutagenic Effect of Air Plasma on Penicillium Chrysogenum

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Plasma Science and Technology 2012年第4期14卷 297-302页

作者：桂芳王辉王鹏刘会蔡晓春胡以华袁成凌郑之明 Key Laboratory of ion beam Bioengineering Chinese Academy of Sciences Electronic Engineering Institute

Low temperature air plasma was used as the mutation tool for penicillin-producing strain Penicillium chrysogenum. The discharge conditions were RF power of 360 W, temperature of 40℃ in a sealed chamber, and pressure of 10 Pa to 30 Pa. The result showed that the kinetics of the survival rate followed a typical saddle-shaped curve. Based on a statistic analysis, at the treating duration of 10 min, the positive mutation rate was as high as 37.5% while the negative mutation rate was low. The colonial morphology changed obviously when the plasma treating duration reached or exceeded 45 min. After both primary and secondary screening, a mutant designated as aPc051310 with high productivity of penicillin was obtained, and a strong mutagenic effect on P. chrysogenurn was observed in the process. It was proved that after five generations, the mutant aPc051310 still exhibits a high productivity. All the results prove that the plasma mutation method could be developed as a convenient and effective tool to breed high-yield strains in the fermentation industry, while expanding the plasm application at the same time.

关键词： low temperature air plasma Penicillium chrysogenum mutation breeding mutation mechanism

Quantitative Assessment of Amino Acid Damage upon keV ion beam Irradiation Through FTIR Spectroscopy

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Plasma Science and Technology 2010年第3期12卷 378-384页

作者：黄青柯志刚苏玺袁航张束清余增亮 Key Laboratory of ion beam Bio-engineering Institute of Plasma Physics of Chinese Academy of Sciences

ion beam irradiation induces important biological effects and it is a long-standing task to acquire both qualitative and quantitative assessment of these effects. One effective way in the investigation is to utilize Fourier transformation infrared （FTIR） spectroscopy because it can offer sensitive and non-invasive measurements. In this paper a novel protocol was employed to prepare biomolecular samples in the form of thin and transversely uniform solid films that were suitable for both infrared and low-energy ion beam irradiation experiments. Under the irradiation of N^＋ and Ar^＋ ion beams of 25 keV with fluence ranging from 5×10^15 ions/cm^2 to 2.5×10^16 ions/cm^2, the ion radio-sensitivity of four amino acids, namely, glycine, tyrosine, methionine and phenylalanine, were evaluated and compared. The ion beam irradiation caused biomolecular decomposition accompanied by molecular desorption of volatile species and the damage was dependent on ion type, fiuence, energy and types of amino acids. The effectiveness of application of FTIR spectroscopy to the quantitative assessment of biomolecular damage dose effect induced by low-energy ion radiation was thus demonstrated.

关键词： ion beam irradiation amino acids IR spectroscopy

Enhancement of Gongronella *** Chitosanase Production by ion beam Implantation

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Plasma Science and Technology 2007年第1期9卷 115-118页

作者：袁航周伟王军张束清姚建铭 Key Laboratory of ion beam Bioengineering Chinese Academy of SciencesHefei 230031China

Gongronella sp. JG was a fungal strain which expressed extracellular chitosanase of about 800 U/L during its growth in production medium. To improve its enzyme production, low energy N＋ implantation was employed to mutate spores of JG. The implantation condition was optimized and the parameters of 15 keV and 60 × breeding experiments. A mutant designated as SG 2.6 × 10^13 ions/cm^2 were selected for further was obtained. It showed increased chitosanase production （1800 U/L） and shortened cultivation period （from 72 h to 60 h）. Five-generation cultivation of SG indicated that its chitosanase production was stable at about 1800 U/L.

关键词： breeding chitosanase Gongronella sp. ion beam implantation

Structure and Growth Mechanism of V/Ag Multilayers with Different Periodic Thickness Fabricated by Magnetron Sputtering Deposition

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Journal of Materials Science & Technology 2014年第10期30卷 1012-1019页

作者： Hongxiu Zhang Feng Ren Mengqing Hong Xiangheng Xiao Guangxu Cai Changzhong Jiang School of Physics and Technology Center for Ion Beam Applicationand Center for Electron MicroscopyWuhan University

V/Ag multilayers with different periodic thicknesses were fabricated by magnetron sputtering deposition. The columnar structure and the orientation relationship of the multilayers were investigated by transmission electron microscopy, high resolution transmission electron microscopy, selected-area electron diffraction and X-ray diffraction. It was found that the multilayered structure became flatter as increasing individual layer thickness from 2 to 6 nm, and then became waved as the individual layer thickness increases to 8 nm. At the beginning of the growth, the morphology of the multilayers with small periodic thickness was influenced mainly by thermodynamic instabilities, and the morphology of the multilayers with larger periodic thickness was mainly influenced mainly by the columnar growth of V. When the waved interfaces were formed, the continuum growth of the multilayers was also influenced by the shadowing effect and the finite atomic size effect. All of these factors resulted in the columnar structure of the multilayers. Multilayers with small periodic thickness presented strong orientation relationship. Nano-hardness tests indicated that multilayers with flat sublayer morphology and clear interfaces exhibited larger hardness.

关键词： Multilayers Interfaces Columnar structure Transmission electron microscopy