In recent years,heavy ion accelerator technology has been rapidly developing worldwide and widely applied in the fields of space radiation simulation and particle therapy.Usually,a very high uniformity in the irradiat...In recent years,heavy ion accelerator technology has been rapidly developing worldwide and widely applied in the fields of space radiation simulation and particle therapy.Usually,a very high uniformity in the irradiation area is required for the extracted ion beams,which is crucial because it directly affects the experimental precision and therapeutic effect.Specifically,ultra-large-area and high-uniformity scanning are crucial requirements for spacecraft radiation effects assessment and serve as core specification for beamline terminal design.In the 300 MeV proton and heavy ion accelerator complex at the Space Environment Simulation and Research Infrastructure(SESRI),proton and heavy ion beams will be accelerated and ultimately delivered to three irradiation terminals.In order to achieve the required large irradiation area of 320 mm×320 mm,horizontal and vertical scanning magnets are used in the extraction beam line.However,considering the various requirements for beam species and energies,the tracking accuracy of power supplies(PSs),the eddy current effect of scanning magnets,and the fluctuation of ion bunch structure will reduce the irradiation uniformity.To mitigate these effects,a beam uniformity optimization method based on the measured beam distribution was proposed and applied in the accelerator complex at SESRI.In the experiment,the uniformity is successfully optimized from 75%to over 90%after five iterations of adjustment to the PS waveforms.In this paper,the method and experimental results were introduced.展开更多
Using ion beam biotechnology in combination with soil-less plant cultivation on artificial substratum (floating beds), the experiments were conducted with Ipomoea aquatica Forsk. Plants were attached to floating-beds ...Using ion beam biotechnology in combination with soil-less plant cultivation on artificial substratum (floating beds), the experiments were conducted with Ipomoea aquatica Forsk. Plants were attached to floating-beds which were placed on the surface of artificially nutrient-enriched tank water, in order to study the purification and remediation efficiency of ion beam-treated I. aquatica cultivars. The results show that N + ion beams with 25keV energy and dosages of 0, 2.6, 3.9, 5.2, 6.5, 7.8, 9.1×10 13N +(ions)/cm 2 affected I. aquatica dry seeds differently, with the dose of 3.9×10 13N + (ions)/cm 2 improving effectively the performance as expressed by various biological indices. After ion beam application, I. aquatica cultivars grew well in nutrient-enriched water bodies, increasing the growth of leaves and stem, number of leaves, length and area of roots, plant height, and weight more remarkably than observed in the control. The net removing rates of TN, TP were as high as 75% and 82%, respectively. Especially under the dose of 3.9×10 13N +(ions)/cm 2, the net removing rates of TN, TP were highest, for 77% and 85%, respectively. It was proved that ion beam application improves phytoremediation and may be used to purify nutrient rich water bodies.展开更多
The high-temperature oxidation resistance behavior of 7% （mass fraction） Y203-ZrO2 thermal barrier coatings （TBCs） irradiated by high-intensity pulsed ion beam （HIPIB） was investigated under the cyclic oxidation...The high-temperature oxidation resistance behavior of 7% （mass fraction） Y203-ZrO2 thermal barrier coatings （TBCs） irradiated by high-intensity pulsed ion beam （HIPIB） was investigated under the cyclic oxidation condition of 1 050 ℃ and 1 h. The columnar grains in the TBCs disappear after the HIPIB irradiation at ion current densities of 100-200 A/cm^2 and the irradiated surface becomes smooth and densified after remelting and ablation due to the HIPIB irradiation. The thermally grown oxide （TGO） layer thickness of the irradiated TBCs is smaller than that of the original TBCs. After 15 cycles, the mass gains of the original TBCs and those irradiated by ion current densities of 100 and 200 A/cm^2 due to the oxidation are found to be 0.8-0.9, 0.6-0.7, and 0.3-0.4 mg/cm^2, respectively. The inward diffusion of oxygen through the irradiated TBCs is significantly impeded by the densified top layer formed due to irradiation, which is the main reason for the improved overall oxidation resistance of the irradiated TBCs.展开更多
为了进一步提高凝结芽孢杆菌NJYHHWG 877005菌株的拮抗性能,获得生防效果更好的菌株,利用低能N^+注入菌株进行诱变,并通过平板对峙培养对诱变处理后的菌株进行筛选。结果表明,菌株存活率曲线遵循N^+注入生物效应的马鞍型曲线,根据其存...为了进一步提高凝结芽孢杆菌NJYHHWG 877005菌株的拮抗性能,获得生防效果更好的菌株,利用低能N^+注入菌株进行诱变,并通过平板对峙培养对诱变处理后的菌株进行筛选。结果表明,菌株存活率曲线遵循N^+注入生物效应的马鞍型曲线,根据其存活率及突变率确定N^+最佳注入能量为15 ke V,最佳注入剂量为140×10^(13)个/cm^2。通过筛选获得1株具有良好性状的突变株L1,芽孢形成率达77.42%,对灰葡萄孢霉菌的抑制率高达87.81%,分别较原始出发菌株提高了23.79、11.71个百分点,且连续传代培养8次,遗传稳定性良好。展开更多
为探究辐照后柿子理化指标和风味品质,本研究采用4种脱涩方法(真空后辐照、辐照后真空、真空脱涩和酒精脱涩)对柿子(Diospyros kaki Thunb.)进行处理,以未辐照组(真空脱涩和酒精脱涩)作为对照组,结合感官评价、质构仪、电子舌、电子鼻...为探究辐照后柿子理化指标和风味品质,本研究采用4种脱涩方法(真空后辐照、辐照后真空、真空脱涩和酒精脱涩)对柿子(Diospyros kaki Thunb.)进行处理,以未辐照组(真空脱涩和酒精脱涩)作为对照组,结合感官评价、质构仪、电子舌、电子鼻和气相色谱-离子迁移谱(GC-IMS)等技术进行分析。结果表明,不同脱涩方法对柿子的pH值、可溶性固形物和可滴定酸含量变化无明显影响。然而,辐照处理较未辐照组显著降低了柿子的硬度,辐照组硬度范围为760.26~786.95 g,而未辐照组硬度则为946.54~1086.88 g。电子舌分析表明,辐照脱涩后柿子的滋味较未辐照组无明显变化,而电子鼻能有效区分辐照与未辐照柿子的气味成分。利用GC-IMS从4种脱涩方法柿子中检测出34个信号峰和25种挥发性风味化合物,其中包括8种醇类、9种醛类、1种酸类、4种酮类和2种酯类。研究发现,辐照处理较未辐照组显著提升了柿子中的醇类和醛类化合物含量,同时降低了酸类、酮类和酯类成分含量。采用偏最小二乘判别分析(PLS-DA)对所有挥发性成分进行分析,发现乙酸乙酯(VIP>1)能够有效区分不同样品。综上所述,电子束辐照作为新型脱涩手段,具有较好的脱涩效果,能够有效保持柿子的外观、口感和风味品质。本研究可为优化柿子的处理方法、提升其风味品质及市场竞争力提供重要的理论依据和实践参考。展开更多
基金Supported by National Key R&D Program of China(2019YFA0405400)。
文摘In recent years,heavy ion accelerator technology has been rapidly developing worldwide and widely applied in the fields of space radiation simulation and particle therapy.Usually,a very high uniformity in the irradiation area is required for the extracted ion beams,which is crucial because it directly affects the experimental precision and therapeutic effect.Specifically,ultra-large-area and high-uniformity scanning are crucial requirements for spacecraft radiation effects assessment and serve as core specification for beamline terminal design.In the 300 MeV proton and heavy ion accelerator complex at the Space Environment Simulation and Research Infrastructure(SESRI),proton and heavy ion beams will be accelerated and ultimately delivered to three irradiation terminals.In order to achieve the required large irradiation area of 320 mm×320 mm,horizontal and vertical scanning magnets are used in the extraction beam line.However,considering the various requirements for beam species and energies,the tracking accuracy of power supplies(PSs),the eddy current effect of scanning magnets,and the fluctuation of ion bunch structure will reduce the irradiation uniformity.To mitigate these effects,a beam uniformity optimization method based on the measured beam distribution was proposed and applied in the accelerator complex at SESRI.In the experiment,the uniformity is successfully optimized from 75%to over 90%after five iterations of adjustment to the PS waveforms.In this paper,the method and experimental results were introduced.
文摘Using ion beam biotechnology in combination with soil-less plant cultivation on artificial substratum (floating beds), the experiments were conducted with Ipomoea aquatica Forsk. Plants were attached to floating-beds which were placed on the surface of artificially nutrient-enriched tank water, in order to study the purification and remediation efficiency of ion beam-treated I. aquatica cultivars. The results show that N + ion beams with 25keV energy and dosages of 0, 2.6, 3.9, 5.2, 6.5, 7.8, 9.1×10 13N +(ions)/cm 2 affected I. aquatica dry seeds differently, with the dose of 3.9×10 13N + (ions)/cm 2 improving effectively the performance as expressed by various biological indices. After ion beam application, I. aquatica cultivars grew well in nutrient-enriched water bodies, increasing the growth of leaves and stem, number of leaves, length and area of roots, plant height, and weight more remarkably than observed in the control. The net removing rates of TN, TP were as high as 75% and 82%, respectively. Especially under the dose of 3.9×10 13N +(ions)/cm 2, the net removing rates of TN, TP were highest, for 77% and 85%, respectively. It was proved that ion beam application improves phytoremediation and may be used to purify nutrient rich water bodies.
基金Projects supported by The 2nd Stage of Brain Korea and Korea Research Foundation
文摘The high-temperature oxidation resistance behavior of 7% （mass fraction） Y203-ZrO2 thermal barrier coatings （TBCs） irradiated by high-intensity pulsed ion beam （HIPIB） was investigated under the cyclic oxidation condition of 1 050 ℃ and 1 h. The columnar grains in the TBCs disappear after the HIPIB irradiation at ion current densities of 100-200 A/cm^2 and the irradiated surface becomes smooth and densified after remelting and ablation due to the HIPIB irradiation. The thermally grown oxide （TGO） layer thickness of the irradiated TBCs is smaller than that of the original TBCs. After 15 cycles, the mass gains of the original TBCs and those irradiated by ion current densities of 100 and 200 A/cm^2 due to the oxidation are found to be 0.8-0.9, 0.6-0.7, and 0.3-0.4 mg/cm^2, respectively. The inward diffusion of oxygen through the irradiated TBCs is significantly impeded by the densified top layer formed due to irradiation, which is the main reason for the improved overall oxidation resistance of the irradiated TBCs.
文摘为了进一步提高凝结芽孢杆菌NJYHHWG 877005菌株的拮抗性能,获得生防效果更好的菌株,利用低能N^+注入菌株进行诱变,并通过平板对峙培养对诱变处理后的菌株进行筛选。结果表明,菌株存活率曲线遵循N^+注入生物效应的马鞍型曲线,根据其存活率及突变率确定N^+最佳注入能量为15 ke V,最佳注入剂量为140×10^(13)个/cm^2。通过筛选获得1株具有良好性状的突变株L1,芽孢形成率达77.42%,对灰葡萄孢霉菌的抑制率高达87.81%,分别较原始出发菌株提高了23.79、11.71个百分点,且连续传代培养8次,遗传稳定性良好。
文摘为探究辐照后柿子理化指标和风味品质,本研究采用4种脱涩方法(真空后辐照、辐照后真空、真空脱涩和酒精脱涩)对柿子(Diospyros kaki Thunb.)进行处理,以未辐照组(真空脱涩和酒精脱涩)作为对照组,结合感官评价、质构仪、电子舌、电子鼻和气相色谱-离子迁移谱(GC-IMS)等技术进行分析。结果表明,不同脱涩方法对柿子的pH值、可溶性固形物和可滴定酸含量变化无明显影响。然而,辐照处理较未辐照组显著降低了柿子的硬度,辐照组硬度范围为760.26~786.95 g,而未辐照组硬度则为946.54~1086.88 g。电子舌分析表明,辐照脱涩后柿子的滋味较未辐照组无明显变化,而电子鼻能有效区分辐照与未辐照柿子的气味成分。利用GC-IMS从4种脱涩方法柿子中检测出34个信号峰和25种挥发性风味化合物,其中包括8种醇类、9种醛类、1种酸类、4种酮类和2种酯类。研究发现,辐照处理较未辐照组显著提升了柿子中的醇类和醛类化合物含量,同时降低了酸类、酮类和酯类成分含量。采用偏最小二乘判别分析(PLS-DA)对所有挥发性成分进行分析,发现乙酸乙酯(VIP>1)能够有效区分不同样品。综上所述,电子束辐照作为新型脱涩手段,具有较好的脱涩效果,能够有效保持柿子的外观、口感和风味品质。本研究可为优化柿子的处理方法、提升其风味品质及市场竞争力提供重要的理论依据和实践参考。
