Low-energy ion beam implantation （10 - 200 keV） has been proved to have a wide range of biological effects and is broadly used in the breeding of crops and micro-organisms.To understand its mechanisms better and fac...Low-energy ion beam implantation （10 - 200 keV） has been proved to have a wide range of biological effects and is broadly used in the breeding of crops and micro-organisms.To understand its mechanisms better and facilitate its applications, the developments in the bioeffects of low energy ion beam implantation in the past twenty years are summarized in this paper.展开更多
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 cha...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.展开更多
Implantation experiments of low energy（1 keV【E【18 keV）hydrogen ion beamson hydrogen loaded metals are performed with high beam density(J<sub>max</sub>1.2 mA/cm<sup>2</sup>)and lowbeam densi...Implantation experiments of low energy（1 keV【E【18 keV）hydrogen ion beamson hydrogen loaded metals are performed with high beam density(J<sub>max</sub>1.2 mA/cm<sup>2</sup>)and lowbeam density(J<sub>min</sub>0.02 mA/cm<sup>2</sup>).Palladium and titanium foils（plates）are bombarded withproton and deuteron beams in order to compare the atomic and nuclear interactions between dif-ferent ion beams.X-ray and charged particles are measured,and neutron and gamma doses arealso monitored during the implantation experiments.An anomalous peak in X-spectra,whoseenergy is about four times the beam energy,is observed during the high beam density experi-ment.The peak moves from about 40 keV to 62 keV and FWHM reduces rapidly,while thebeam energy and intensity increase.Another wide peak with over twice the beam energy is mea-sured in experiment with low beam density.It is located between 16 keV and 30 keV,and itspeak energy increases with the increase of implantation dose（implantation time）.Some anoma-lous intensities of neutrons correlated with a charged particle peak（2.93,3.85 MeV）are alsoobserved in the deuteron-palladium experiment.The highest neutron intensity reaches about8×10<sup>4</sup> n/s,while the beam energy and intensity are about 15 keV and 1.0 mA,respectively.展开更多
As reported in this paper, a strain of oil-degrading bacterium Sp - 5 - 3 was determined to belong to Enterobacteriaceae, which would be useful for microbial enhanced oil recovery (MEOR). The aim of our study was to g...As reported in this paper, a strain of oil-degrading bacterium Sp - 5 - 3 was determined to belong to Enterobacteriaceae, which would be useful for microbial enhanced oil recovery (MEOR). The aim of our study was to generate a mutant using low energy N+ beam implantation. With 10 keV of energy and 5.2× 1014 N+/cm2 of dose - the optimum condition, a mutant, S-34, was obtained, which had nearly a 5-fold higher surface and a 13-fold higher of emulsifica-tion activity than the wild type. The surface activity was measured by two methods, namely, a surface tension measuring instrument and a recording of the repulsive circle of the oil film; the emulsification activity was scaled through measuring the separating time of the oil-fermentation mixture. The metabolic acid was determined as methane by means of gas chromatography.展开更多
We developed a cluster ion beam system that produces negative cluster beams of C 1-C 10 with ion current of 4.5 nA-50 A at extraction voltages ranging from 6 to 20 kV.The system uses the injector of a tandetron accele...We developed a cluster ion beam system that produces negative cluster beams of C 1-C 10 with ion current of 4.5 nA-50 A at extraction voltages ranging from 6 to 20 kV.The system uses the injector of a tandetron accelerator and was established by inserting an electrostatic scanner on its ion-optical line and modifying its Faraday cup into a substrate holder.Utilization of clusters enables ultrashallow ion implantation at energies as low as 600 eV/atom without deceleration.Small carbon clusters C 2 and C 4 were implanted into Ni/SiO 2 /Si substrates and following post-thermal treatment graphene was obtained.Raman spectroscopy showed characteristic 2D peaks with G-to-2D peak ratios revealing formation of 2-3 layers of graphene.The Raman data reveals clear effect of nonlinear cluster-surface interaction in ion beam synthesis of two-dimensional nanomaterials.展开更多
文摘Low-energy ion beam implantation （10 - 200 keV） has been proved to have a wide range of biological effects and is broadly used in the breeding of crops and micro-organisms.To understand its mechanisms better and facilitate its applications, the developments in the bioeffects of low energy ion beam implantation in the past twenty years are summarized in this paper.
基金supported by the Knowledge Innovation Project of the Chinese Academy of Sciences (No.KSCX2-SW-324)
文摘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.
文摘Implantation experiments of low energy（1 keV【E【18 keV）hydrogen ion beamson hydrogen loaded metals are performed with high beam density(J<sub>max</sub>1.2 mA/cm<sup>2</sup>)and lowbeam density(J<sub>min</sub>0.02 mA/cm<sup>2</sup>).Palladium and titanium foils（plates）are bombarded withproton and deuteron beams in order to compare the atomic and nuclear interactions between dif-ferent ion beams.X-ray and charged particles are measured,and neutron and gamma doses arealso monitored during the implantation experiments.An anomalous peak in X-spectra,whoseenergy is about four times the beam energy,is observed during the high beam density experi-ment.The peak moves from about 40 keV to 62 keV and FWHM reduces rapidly,while thebeam energy and intensity increase.Another wide peak with over twice the beam energy is mea-sured in experiment with low beam density.It is located between 16 keV and 30 keV,and itspeak energy increases with the increase of implantation dose（implantation time）.Some anoma-lous intensities of neutrons correlated with a charged particle peak（2.93,3.85 MeV）are alsoobserved in the deuteron-palladium experiment.The highest neutron intensity reaches about8×10<sup>4</sup> n/s,while the beam energy and intensity are about 15 keV and 1.0 mA,respectively.
基金The project supported by the Knowledge Innovation Project of the Chinese Academy of Sciences(No. KSCX2-SW-324)
文摘As reported in this paper, a strain of oil-degrading bacterium Sp - 5 - 3 was determined to belong to Enterobacteriaceae, which would be useful for microbial enhanced oil recovery (MEOR). The aim of our study was to generate a mutant using low energy N+ beam implantation. With 10 keV of energy and 5.2× 1014 N+/cm2 of dose - the optimum condition, a mutant, S-34, was obtained, which had nearly a 5-fold higher surface and a 13-fold higher of emulsifica-tion activity than the wild type. The surface activity was measured by two methods, namely, a surface tension measuring instrument and a recording of the repulsive circle of the oil film; the emulsification activity was scaled through measuring the separating time of the oil-fermentation mixture. The metabolic acid was determined as methane by means of gas chromatography.
基金supported by the International Cooperation Program of the Ministry of Science and Technology of China (2010DFA02010)
文摘We developed a cluster ion beam system that produces negative cluster beams of C 1-C 10 with ion current of 4.5 nA-50 A at extraction voltages ranging from 6 to 20 kV.The system uses the injector of a tandetron accelerator and was established by inserting an electrostatic scanner on its ion-optical line and modifying its Faraday cup into a substrate holder.Utilization of clusters enables ultrashallow ion implantation at energies as low as 600 eV/atom without deceleration.Small carbon clusters C 2 and C 4 were implanted into Ni/SiO 2 /Si substrates and following post-thermal treatment graphene was obtained.Raman spectroscopy showed characteristic 2D peaks with G-to-2D peak ratios revealing formation of 2-3 layers of graphene.The Raman data reveals clear effect of nonlinear cluster-surface interaction in ion beam synthesis of two-dimensional nanomaterials.
