SRAP Marker Analysis of Genomic Mutation Induced by ^(60)Coγ-Ray Irradiation in Potato (Solanum tuberosum)

[Objective] This study was to explore the mutagenic effect of 60Co γ-ray on Solanum tuberosum chromosomes.[Method] The 60Co γ-ray at different irradiation doses was applied to treat the minitubers of potato variety ＇Favorita＇,and the genomic mutations in VM1 and VM2 gene rations in treatments with different doses were analyzed by SRAP markers.[Resalt] Thirty pairs of SRAP primers out of 88 pairs exhibited polymorphism with a rate of 34.1％ in the bulked selection of VM1 generation.A total of 225 bands were obtained,of which 64 were polymorphic with a rate of 28.4％.The polymorphism was reflected in the forms of deleted bands and added bands.Based on the result of the bulked selection of VM1 generation,25 primers with polymorphism were selected to scan VM2 generation.Five primers performed poorly,and nine of the rest 20 pairs revealed polymorphism and obtained nine polymorphic bands,of which only four bands were detected in VM1 generation and the other five ones were newly deleted bands.Only 9.8％ of the bands detected in VM1 generation were obtained in VM2 generation.Eventually,nine stable and dear polymorphic bands were recovered and cloned,and DNA sequences of six bands of them were acquired by sequencing.According to the comparative analysis,five fragments sequences were similar to potato chromosome with a similarity rate of 77％-89％,three of them located at the resistance gene cluster; another one fragment had a similarity of 93％ with some regions of the No.5 chromosome in tomato.[Conclusion] 60Co γ-ray irradiation can cause mutation of genomic DNA in potato;there is no significant correlation between the number of polymorphic bands and the irradiation dose; potymorphic bands are characterized by a larger number of deleted bands than that of the added ones.

γ-Ray Irradiation-Derived MnO/rGO Composites for High Performance Lithium Ion Batteries

We report a γ-ray irradiation reduction method to prepare MnO/reduced graphene oxide （rCO） nanocomposite for the anode of lithium ion batteries. γ-Ray irradiation provides a clean way to generate homogeneously dispersed MnO nanoparticles with finely tuned size on rGO surface without the use of surfactant. The MnO/rGO composite enables a fully charge/discharge in 2 min to gain a reversible specific capacity of 546 （mA-h）/g which is 45 higher than the theoretical value of commercial graphite anode.

Study on γ-Ray Irradiation Mutation of Bacillus subtilis NCD-2

[Objective] To study the effect of 60Co γ-rays irradiation on Botrytis cinerea biocontrol strains—Bacillus subtilis NCD-2. [Method] NCD-2 cells were irradiated at different doses of γ-rays from 100 to 2 000 Gy. The strains were screened by plate confrontation method and Oxford cup diffusion. [Result] The curves of the relationship of irradiation dose and mutation and lethal rate were obtained. The results showed that lethal rate increased with the increasing of irradiation dose. The lethal rate of 1 000 Gy irradiation dose reached 99.50%. The mutation rate increased below 500 Gy and decreased above 500 Gy. The highest mutation rate occurred when the irradiation dose was between 400 and 700 Gy, and the average mutation rate was above 15%. The optimal irradiation dose was 500 Gy, when the average mutation rate was 26.51% and lethal rate was 77.71%. [Conclusion] This study provided references for γ-rays irradiation mutation of Bacillus subtilis.

Preparation of Thermal-responsive Chitosan-graft-N-isopropyl- acrylamide Membranes via γ-Ray Irradiation

A novel thermo-sensitive switching membrane has been prepared by radiation-induced simultaneous grafting N-isopropylacrylamide （NIPAAm） onto chitosan membrane. Fourier transform infrared spectroscopy （FTIR） was used to identify the structure of the grafted membranes. The surface morphology of the grafted membrane was observed from scanning electron microscopy （SEM）. Pure water flux measurements showed that water flux of the grafted membrane decreased with the increase of temperature, while that of chitosan membrane was constant. It was proved that grafted membrane was sensitive to temperature.

Novel Method of Preparation of Monolithic Columns for Fast Separation byγ-Ray Irradiation

A porous monolithic sol-gel column with the solution of methacryloxypropyltrimethoxysilane in toluene with an acid catalyst was prepared in the presence and absence of sodium dodecyl sulfate. In situ polymerization was carded out by γ-ray irradiation within the capillary. The γ-radiation-initiated synthesis could generate radicals directly on the monomer avoiding use of any initiator. The chromatographic behavior of the capillary monolithic columns were studied in the modes of CEC, p-CEC and low pressure-driven separation, all the tests exhibited reversed-phase character. It provided a viable alternative to either thermally initiated or photo polymerization method for the preparation of monolithic columns.

The effect ofγ-ray irradiation on the SOT magnetic films and Hall devices

Magnetoresistive random access memories(MRAMs)have drawn the attention of radiation researchers due to their potential high radiation tolerance.In particular,spin-orbit torque MRAM(SOT-MRAM)has the best performance on endurance and access speed,which is considered to be one of the candidates to replace SRAM for space application.However,little attention has been given to theγ-ray irradiation effect on the SOT-MRAM device yet.Here,we report the Co-60 irradiation results for both SOT(spin-orbit torque)magnetic films and SOT-Hall devices with the same stacks.The properties of magnetic films are not affected by radiation even with an accumulated dose up to 300 krad(Si)while the magnetoelectronic properties of SOTHall devices exhibit a reversible change behavior during the radiation.We propose a non-equilibrium anomalous Hall effect model to understand the phenomenon.Achieved results and proposed analysis in this work can be used for the material and structure design of memory cell in radiation-hardened SOT-MRAM.

Differential Expression of Retrotransposon WIS 2-1A Response to Vacuum, Low-Energy N^+ Implantation and ^(60)Coγ-ray Irradiation in Wheat

Mutagenesis and retrotransposons have a close relationship, but little attention has been paid yet to the activity of retrotransposons produced by physical mutagens. The variation of retrotransposon WIS 2-1A activity in wheat （Triticum aestivum L.） embryos at three different growth times （30 h, 45 h and 60 h） was investigated after they had been treated with N^＋ implantation in a vacuum of 5× 10^-2 Pa and irradiation by ^60Coγ-ray respectively. For each of the three growth times the expression of WIS 2-1A showed almost entirely a same trend of downregulation, upregulation, then downregulation, and upregulation again with the increase in dose of N^＋ implantation, but the expression appeared irregular with the increase in irradiation of ^60Coγ-ray. In conclusion, the acutely activating effect of WIS 2-1A stimulated by vacuum and high dose N^＋ implantation within a shorter incubation time may provide a convenient tool to advance the research on mutagenic breeding and function genes.

The Degradation of FB1 in Aqueous Acetonitrile and Corn Following γ-ray Irradiation

To investigate the degradation of FB1 in aqueous acetonitrile and corn af-ter γ-ray irradiation, the radiolytic products of FB1 was detected preliminarily. The results showed that γ-ray irradiation could degrade FB1 in aqueous acetonitrile;When the radiation dose was below 9 kGy, the degradation of FB1 in corn was not significant. The degradation rates of FB1 with concentrations of 0.8 mg/ml, 10.0 μg/ml, 1.0 μg/ml and 50 ng/ml after irradiation at 9 kGy were 22.5%, 51.0%, 59.0% and 64.8% respectively; when irradiation dose was increased to 100 kGy, the degrada-tion rate of FB1 with concentration of 0.8 mg/ml was up to 90%, and it was nearly 100% when irradiation dose was increased to 200 kGy. No representative products of FB1 were detected by LC/MS/MS analysis.

Enhanced Enzymatic Hydrolysis of Miscanthus sinensis Following Synergic Pretreatment with ^(60)Co γ-ray Irradiation and Alkaline Hydrogen Peroxide

[Objective] This study aimed to investigate the effects of different pretreat- ments on enzymatic saccharification of Miscanthus sinensis and improve reducing sugar yield in the enzymolysis process. [Method] M. sinensis was pretreated with 60Co y-ray irradiation and alkaline hydrogen peroxide, to analyze their effects on re- ducing sugar yield of enzymatic hydrolysis. [Result] After pretreatment with 400 kGy 60Co y-ray irradiation, reducing sugar yield in the enzymolysis process of M sinensis was 76.24 mg/g; after synergic pretreatment with 400 kGy 60Co y-ray irradiation and alkaline hydrogen peroxide, reducing sugar yield in the enzymolysis process of M. sinensis was 505.08 mg/g, which was improved by 5.6 times compared to that in pretreatment with 400 kGy 60Co y-ray irradiation. Based on process optimization, the optimal hydrolysis conditions were obtained： pretreatment temperature 30 ℃, NaOH concentration 1.2%, hydrogen peroxide concentration 2%, pretreatment time 6 h. [Conclusion] Synergic pretreatment with 60Co y-ray irradiation and alkaline hydrogen peroxide could significantly improve reducing sugar yield in the enzymolysis process of M. sinensis, which provided a new theoretical basis for preparing fuel ethanol with M. sinensis.

Preparation and Characterization of Fe3O4 Magnetic Nano-particles by ^（60）Co γ-ray Irradiation

By using a new method, ^60Co γ-ray irradiation, Fe3O4 magnetic nano-particles were successfully synthesized at room temperature under ambient pressure. The structure, morphology and magnetic properties of these nanoparticles were characterized by X-ray diffraction （XRD）, transmission electron microscope （TEM） and vibrating sample magnetometer （VSM）, respectively. The radiation formation mechanism was also discussed. The results show that the absorbed dose can greatly influence the structure, morphology and magnetic properties of the products. XRD and TEM studies show that the product prepared by γ-ray irradiation （10 kGy） is pure FesO4 phase and the mean diameter of these nano-particles is about 21 nm. The Fe3O4 nano-particles synthesized by γ-ray irradiation （10 kGy） are mainly in small cubic shape and the size uniformity of these particles is good.

Degradation of nitrobenzene in wastewater by γ-ray irradiation

The degradation of nitrobenzene(NB) by γ ray irradiation was studied. The influences of dose rate and initial NB concentration were investigated in details. At a dose rate of 55 Gy/min, the degradation kinetics was pseudo first order at NB concentrations from 0 2 mmol/L to 4 0 mmol/L. At an initial NB concentration of 0 8 mmol/L, the degradation of NB at various dose rates also followed pseudo first order kinetics. Dissolved oxygen was found to have a positive effect on NB degradation. The degradation products were identified as nitrophenol, nitrosobenzene, and hydroquinone, and so on. Based on the product analysis, possible degradation pathways of nitrobenzene were proposed.

Decolorization Kinetics of Sludge Protein Solution by ^(60)Coγ-Ray Irradiation/H_2O_2 Oxidation

In order to carry out decolorization, sludge protein solution, a dark brown close to black solution from activated sludge, was subjected to ^(60)Co γ-ray irradiation in the presence of hydrogen peroxide. UV/Vis spectrophotometric method was used to investigate the effect of H2O2 on the coloration apparent kinetics and rate constants of sludge protein solution under γ-ray irradiation. In addition, the effects of irradiation dose, initial sludge protein solution concentration, and pH value on the decolorization efficiency of sludge protein solution were studied. Results showed that the decolorization apparent kinetics of sludge protein solution was a first-order reaction. The solution decolorization percentage increased with the increase of irradiation dose or the decrease of initial sludge protein solution concentration. The examination results of pH value showed that the sludge protein solution could be more efficiently decolorized in alkaline media than in acid media. Moreover, sensory evaluation and foamability analysis indicated that irradiated samples under H2O2 oxidation showed better sensory score and foamability.

The effects of ^(60)Co γ-ray irradiation on the DC characteristics of enhancement-mode AlGaN/GaN high-electron-mobility transistors

The effects of ^60Co γ-ray irradiation on the DC characteristics of AlGaN/GaN enhancement-mode high-electron- mobility transistors （E-mode HEMTs） are investigated. The results show that having been irradiated by^60Co γ-rays at a dose of 3 Mrad （Si）, the E-mode HEMT reduces its saturation drain current and maximal transconductance by 6% and 5%, respectively, and significantly increases both forward and reverse gate currents, while its threshold voltage is affected only slightly. The obvious performance degradation of E-mode A1GaN/GaN HEMTs is consistent with the creation of electronegative surface state charges in the source-gate spacer and gate-drain spacer after being irradiated.

Properties of radicals created by γ-ray irradiation of silk fabrics

The propoerties of radicals fromγ-ray irradiated silk fabrics were studied by electron spin resonance method(ESR).The ESR spectra of silk fabrics irradiated in N2 showed a doublet at room temperature,The doublet became a singlet at g=2.0057 after placing the sample in air for 24 hours.This can be explained by formation of peroxide radicals.The radical concentration of the irradiated silk fabric and the decay rate of radicals are significantly affected by irradiation conditions.which include the absorbed dose.atmosphere,and water content of the silk fabric samples.However,no dose rate effect on the radical concentration was observed.The results are of help in our practice of property modification of silk products by radiation graft copolymerization.

γ-ray irradiation effect on siloxane foam containning phenyl

The 60Co γ radiation effect on spherical open-porous polymethylphenylvinyl siloxane foam was studied in different atmospheres at room temperature. The physical and chemical behaviors of unirradiated and irradiated materials were studied by SEM, FTIR, TG (thermal gravity analysis), GC/MS(gas chromatography and mass spec -troscopy), etc. The present results indicate that the yields of gas products increase linearly with the dose increasing. Furthermore, some changes in material’s microscopic form, composition, structure and mechanical property were observed, but the maxi -mum thermal decomposition temperature of the sample alters little and the dose gives no effect on it.

Two-dimensional particle-in-cell modeling of blow-off impulse by X-ray irradiation

Space objects such as spacecraft or missiles may be exposed to intense X-rays in outer space,leading to severe damage.The reinforcement of these objects to reduce the damage caused by X-ray irradiation is a significant concern.The blow-off impulse(BOI)is a crucial physical quantity for investigating material damage induced by X-ray irradiation.However,the accurate calculation of BOI is challenging,particularly for large deformations of materials with complex configurations.In this study,we develop a novel two-dimensional particle-in-cell code,Xablation2D,to calculate BOIs under far-field X-ray irradiation.This significantly reduces the dependence of the numerical simulation on the grid shape.The reliability of this code is verified by simulation results from open-source codes,and the calculated BOIs are consistent with the experimental and analytical results.

Effects of γ-Ray Irradiation on the Fatigue Strength, Thermal Conductivities and Thermal Stabilities of the Glass Fibres/Epoxy Resins Composites

Glass fibres/epoxy resins composites have been performed as ideal materials to make support instruments for high-energy and nuclear physics experiments. The effects of the 3,-ray irradiation on the fatigue strength, thermal conductivities and thermal stabilities of the glass fibres/epoxy resins composites were investigated. And a two-parameter fatigue life model was established to predict the fatigue life of the composites. Results revealed that the y-ray irradiation could probably result in the degradation of epoxy resins, but hardly damage to the glass fibres. And the γ-ray irradiation treatment could significantly affect the fatigue strength of the composites at a low-cycle fatigue stage, but seldom influence at a high-cycle fatigue stage. Furthermore, the fabricated glass fibres/epoxy resins composites after the γ-ray irradiation still presented excellent fatigue strength, ideal thermal conductivities, remarkable dimensional and thermal stabilities, which can meet the actual requirements of normal operation for supporting instruments under high-energy and nuclear physics experiments.

Stability of pyrrolidone derivatives against γ-ray irradiation

To evaluate the stability of N-alkylated pyrrolidone derivatives （NRPs）, which are supposed to be used as precipitants for U（VI） and Pu（IV, VI） species in HNO3 media, under irradiation environment, some candidate NRPs were irradiated by γ-ray. Irradia- tion to HNO3 solutions up to 6 mol dm-3 （= M） containing 2 M N-n-butyl-2-pyrrolidone （NBP）, one of NRPs with lower hy- drophobicity, has revealed that the residual ratios of NBP in the samples of HNO3 up to 3 M decreased identically and linearly. Approximately 20% of NBP was found to be degraded after the irradiation at 1 MGy. It was also found that the decrease in the precipitation ratio of UOf＋ （P.R., %） was gentle and that the P.R. values were relatively in accordance with the residual ratios of NBP. On the other hand, the degradation of the samples irradiated in 6 M HNO3 was found more distinguished. It was pro- posed from the analyses of degraded compounds that the degradation of NBP in HNO3 by γ-ray irradiation started from the cleavage of the pyrrolidone ring by the addition of oxygen atom originating from HNO3, followed by the formation of chain compounds by the successive addition of oxygen, leading to the generation of oxalic acid and acetic acid. The stability of other NRPs in 3 M HNO3 was evaluated to be nearly identical with that of NBP except lower P.R. values of the samples containing NRPs with higher hydrophobicity irradiated at more than 0.5 MGy.

Highly pressure-sensitive graphene sponge fabricated by γ-ray irradiation reduction

Graphene sponge(GS) with microscale size, high mechanical elasticity and electrical conductivity has attracted great interest as a sensing material for piezoresistive pressure sensor. However, GS offering a lower limit of pressure detection with high gauge factor, which is closely dependent on the mechanical and electrical properties and determined by the fabrication process, is still demanded. Here, γ-ray irradiation reduced GS is reported to possess a gauge factor of 1.03 kPa^–1 with pressure detection limit of 10 Pa and high stress retention of 76% after 800 cycles of compressing/relaxation at strain of 50%. Compared with the carbon nanotube(CNT) reinforced GS, the improved lower limit of pressure detection and gauge factor of the GS prepared by γ-ray irradiation is due to the low compression stress(0.9 kPa at stain of 50%). These excellent physical properties of the GS are ascribed to the mild,residual free, and controllable reduction process offered by γ-ray irradiation.

Mutagenic Effect of ^(60)Co γ-rays Irradiation on Turf Characteristics of Buchloe dactyloides (Nutt.) Engelm.

[Objective] This study aimed to investigate the mutagenic effect of 60 Co γ-rays irradiation on turf characteristics of Buchloe dactyloides （Nutt.） Engelm. [Method] Buffalo grass were irradiated with 60 Co γ-rays at five different radiation intensities （1 200, 1 400, 1 600, 1 800, 2 000 Gy） to determine the related turf characteristics and analyze the mutagenic effect of 60 Co γ-rays at different radiation intensities on buffalo grass. [Result] Germination rates of buffalo grass irradiated by different radiation intensities of 60 Co γ-rays varied inconsistently, and the root length and bud length were shorter than the control; compared with the control, the height of irradiated seedlings was significantly reduced, and the number of tillers, plant height, leaf length and leaf blade width were smaller than the control; however, the stolon length, stolon diameter and number of stolon nods had no significant difference compared with the control. [Conclusion] This study laid foundation for determining the appropriate radiation intensity of 60 Co γ-rays and selecting useful mutants of buffalo grass.