Subjects: Nuclear Science and Technology >> Nuclear Materials and Techniques submitted time 2023-06-18 Cooperative journals: 《Nuclear Science and Techniques》
Abstract： The multi-layer parylene (PP) films were irradiated by hot electrons with a dose of 2×1016 cm‒2. The irradiated and non-irradiated films have been examined by FT IR, UV-Vis and strain-stress measurement instruments. The results show that the damage has been created for irradiated films, including benzene rings and broken C-C bonds. The absorbance on the vision light increases and the Yang’s modulus decreases greatly in irradiated films with the worse toughness. The experimental conditions determine whether these effects hinder hydrodynamic instability or not.
Subjects: Physics >> Condensed Matter: Structural, Mechanical and Thermal Properties submitted time 2017-03-26
Abstract： Solution annealed type 316L austenitic stainless steels were irradiated using 2 MeV Fe ions at room temperature. The implanted fluences were 2012 ions/cm2 and 1013 ions/cm2, respectively. Variable mono-energetic positron beam was performed to characterize the evolution of microstructure and irradiation induced defects. Results show that large amount of vacancy defects formed after heavy ion irradiation. In which, some of mono-vacancies might migrate to form small-sized clusters at room temperature. After irradiation, implanted Fe atoms mainly be interstitials atoms, but some Fe atoms might recombine with vacancies due to their high mobility, which could decrease the defect concentration, effectively.
Peer Review Status:
Awaiting Review
Subjects: Physics >> Nuclear Physics submitted time 2024-01-27
Shengyun ZHU
Daqing YUAN
Cong LIU
Hailiang MA
Ping FAN
Ke LI
Qiaoli ZHANG
Ai-Bing DU
Wei FENG
Xiping SU
Abstract： The swelling behavior of titanium-modified austenitic stainless steel 15-15Ti was investigated by pre-implantation of He at room temperature followed by Ni irradiation at 580 °C to peak doses of 120, 240 and 400 dpa. Relatively smaller cavities were observed in the zone of helium implantation while large cavities appeared in the region near the damage peak. A correction formula of the dpa curve was proposed and applied for samples with large swelling. It is found that the steady-state swelling rate of 15-15Ti keeps at ~1% /dpa even to high doses. By comparing the swelling data of the helium-implanted and helium-free regions at same doses, 70 dpa and 122 dpa, the suppression of excessive helium on swelling can be deduced at such doses.
Subjects: Physics >> Nuclear Physics submitted time 2025-04-17
Bai, Dr. Ruxue
Guo, Prof. Hong-xia
Li, Mr. Yangfan
Ma, Dr. Wuying
Li, Dr. Jifang
Zhang, Mr. Feng-Qi
Ouyang, Dr. Xiaoping
Zhong, Prof. Xiangli
Abstract： Gallium nitride (GaN)-based devices are highly attractive candidates for space and aeronautics due to their wide band gap and high critical electric field. However, the mechanism of radiation damage and long-term application reliability of the device are still unclear. This study systematically examines the degradation mechanisms of gate oxide layers in Cascode GaN power devices under proton irradiation at different energy levels. The typical degradation of electrical properties was observed. Following 25 MeV proton irradiation, the gate leakage current increased from 4.18×10-12 A to 4.42×10-10 A. After 60 MeV proton irradiation, the gate leakage current rose from 3.88×10-12 A to 3.81×10-10 A. In contrast, no significant change in gate current was observed after 100 MeV proton irradiation. Time-dependent dielectric breakdown (TDDB) analysis confirmed an elevated risk of gate current leakage under proton irradiation. Proton irradiation increases defect density in the device oxide layer, leading to the formation of leakage paths. In addition, SRIM simulation results based on Monte Carlo indicated that the interaction cross section between low-energy protons and target nuclei is larger, which will cause more defects in the device, leading to the low-energy proton damage becoming more severe. These radiation-induced defects in the gate oxide layer accelerate dielectric breakdown, ultimately compromising the device's long-term reliability.
Peer Review Status:Awaiting Review
Subjects: Physics >> Nuclear Physics submitted time 2025-01-06
Bai, Dr. Ruxue
Guo, Prof. Hong-xia
Li, Mr. Yangfan
Ma, Dr. Wuying
Li, Dr. Jifang
Zhang, Mr. Feng-Qi
Ouyang, Dr. Xiaoping
Zhong, Prof. Xiangli
Abstract： In this paper, the effects of proton irradiation with different energies on the long-term reliability of gate-oxide in Cascode enhanced GaN power device is studied. The typical degradation of electrical properties was observed. In contrast, the gate current was increased by about two orders of magnitude after 25 MeV and 60 MeV proton irradiation, while the gate current was unchanged significantly after 100 MeV proton irradiation. By using time-dependent dielectric breakdown (TDDB) method confirms that the risk of gate current leakage is increased under proton irradiation. The breakdown time of gate dielectric becomes shorter after proton irradiation, which is not conducive to the long-term and stable application of GaN power devices. In addition, SRIM simulation results show that the interaction cross section between low-energy protons and target nucleus is larger, which will cause more defects in the device, leading to the low-energy proton damage becomes more severe. Proton irradiation produces defects in the gate-oxide layer that shorten the breakdown time of the device gate-oxide layer, ultimately resulting the long-term reliability of the device was reduced.
Peer Review Status:Awaiting Review
Subjects: Materials Science >> Materials Chemistry submitted time 2017-10-31
Abstract： Incorporating noble metal nanoparticles on the surface or inner side of semiconductors to form a hybrid nanostructure is an effective route to improve the gas sensing performance of these semiconductors. In this study, we present novel Au-decorated ZnO nanospheres (Au-ZnO NSs) obtained by laser irradiation of liquids. Structural characterization indicated that the Au-ZnO NSs consisted of single crystalline ZnO NSs with few Au nanoparticles decorated on their surfaces and abundant encapsulated Au nanoparticles with relatively small sizes. Laser irradiation-induced heating–melting–evaporating processes are responsible for the formation of unique Au-ZnO NSs. Gas sensing properties of the Au-ZnO NSs, as gas sensing materials, were investigated and compared with those of pure ZnO NSs. The former showed lower working temperature, higher sensitivity, better selectivity, and good reproducibility. The response values of Au-ZnO NSs and pure ZnO NSs sensors to ethanol of 100 ppm were 252 and 75 at working temperature of 320 °C and 360 °C, respectively. The significant enhancements in gas sensing performance should be attributed to the electronic sensitization induced by the depleted layers between encapsulated Au nanoparticles and ZnO and chemical sensitization originating from the catalytic effects of Au nanoparticles decorated on the surfaces that dissociated molecular oxygen.
Peer Review Status:Awaiting Review
Subjects: Physics >> Condensed Matter: Structural, Mechanical and Thermal Properties submitted time 2017-03-26
Abstract：Abstract. The microstructural features and the effect of Mo addition in FeCrNi austenitic alloy during incubation period were investigated using positron annihilation technique and micro-Vickers Hardness. The electron irradiation, which could induce vacancy defects in material, was performed at room temperature up to the dose of 1.70-4 and 50-4 dpa, respectively. The defect concentration was estimated about 10-4-10-7 though the standard trapping model. The added Mo atoms could trap vacancies to form Mo-vacancy complexes, which may restrain the migration and growth of vacancy defects during electron irradiation. In addition, the microstructural evolution during electron radiation resulted in hardening, while the added Mo might improve the hardening property of the alloy.
Peer Review Status:Awaiting Review
Subjects: Nuclear Science and Technology >> Nuclear Materials and Techniques submitted time 2023-06-18 Cooperative journals: 《Nuclear Science and Techniques》
Abstract： The formation of bromate, a classified potential carcinogen, is of great concern when disinfection processes are used for treating high-bromide drinking waters. Bromide-containing aqueous solutions with various additives were irradiated by 60Co γ source. With a 2.0 kGy irradiation of N2O-saturated solutions at initial bromide concentrations of 180.2 μgl-1, 416.9 μgl-1, 663.1 μgl-1 and 823.9 μgl-1. 79.5%, 84.0%, 87.3% and 88.3% of bromide ions were transformed to bromate, respectively. Addomg CO32-/HCO3- or NO3- ions into N2O-saturated bromide solutions, the amount of bromate ions formed decreased with increasing concentrations of the additives. On the other hand, the bromate concentration was all below the detection limit of 1 μgl-1 whenever N2O was not added to quench eaq- and ·H. The results indicated that γ-rays irradiation could be used as a disinfection process, instead of ozonation, to comply with upcoming more stringent regulations, especially in waters containing high concentrations of bromide.
Subjects: Nuclear Science and Technology >> Nuclear Materials and Techniques submitted time 2023-06-18 Cooperative journals: 《Nuclear Science and Techniques》
Abstract： In this paper, the changes of rice-starch’s viscosity at different dose irradiation treatment were studied, the rice can be easily distinguished whether it has been irradiated or not with the control of pH. The results showed that the starch’s viscosity was significantly declined with increasing irradiation absorb dose. With the control of pH 2.5, the irradiated starch’s viscosity was apparently higher than the un-irradiated ones, there are significant differences in terms of viscosity between the two parts. The rice absorbed dose can be estimated using the relationship among peak viscosity, hot pasting viscosity and absorbed dose.
Subjects: Nuclear Science and Technology >> Nuclear Materials and Techniques submitted time 2023-06-18 Cooperative journals: 《Nuclear Science and Techniques》
Abstract： In order to confirm whether the rice sample was exposed to gamma radiation, the changes in starch pasting viscosity of rice irradiated by different absorbed doses with additive acid solution and distilled water were investigated. The peak viscosity of irradiated rice sample was significantly decreased with the increment of absorbed doses even for the samples stored over 360 days. Irradiation samples can be distinguished from non-irradiated samples by their RVA profile as in the acid solution (pH=2.5), the starch pasting viscosities of irradiated rice samples were apparently higher while the starch pasting viscosities of non-irradiated rice samples were lower than that in distilled water (pH=7.0). The irradiation absorbed dose can be estimated accurately by the regression equation constructed with peak viscosity and absorbed doses.
Subjects: Physics >> Interdisciplinary Physics and Related Areas of Science and Technology submitted time 2021-03-24
Abstract： "
Peer Review Status:Awaiting Review
Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. submitted time 2017-08-18
Abstract：Incorporating noble metal nanoparticles on the surface or inner side of semiconductors to form a hybrid nanostructure is an effective route to improve the gas sensing performance of these semiconductors. In this study, we present novel Au-decorated ZnO nanospheres (Au-ZnO NSs) obtained by laser irradiation of liquids. Structural characterization indicated that the Au-ZnO NSs consisted of single crystalline ZnO NSs with few Au nanoparticles decorated on their surfaces and abundant encapsulated Au nanoparticles with relatively small sizes. Laser irradiation-induced heating–melting–evaporating processes are responsible for the formation of unique Au-ZnO NSs. Gas sensing properties of the Au-ZnO NSs, as gas sensing materials, were investigated and compared with those of pure ZnO NSs. The former showed lower working temperature, higher sensitivity, better selectivity, and good reproducibility. The response values of Au-ZnO NSs and pure ZnO NSs sensors to ethanol of 100 ppm were 252 and 75 at working temperature of 320 °C and 360 °C, respectively. The significant enhancements in gas sensing performance should be attributed to the electronic sensitization induced by the depleted layers between encapsulated Au nanoparticles and ZnO and chemical sensitization originating from the catalytic effects of Au nanoparticles decorated on the surfaces that dissociated molecular oxygen.
Peer Review Status:Awaiting Review
Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. submitted time 2017-05-02
Abstract： The uptake of synovial lipids into ultra high molecular weight polyethylene [UHMWPE] has been recently related with the in vivo and ex vivo oxidation of irradiated and remelted UHMWPE. Natural polyphenols have been demonstrated effective in protecting hig
Peer Review Status:Awaiting Review
Subjects: Nuclear Science and Technology >> Radiation Physics and Technology submitted time 2024-08-22
Hong-Xia Xu
Jian-Dang Liu
Bang-Jiao Ye
Zi-Wen Pan
Jun Lin
Jin-Liang Song
Jian-Qing Cao
Chao Yan
Ying-Ping Hao
Jin-Xing Cheng
Qing-Bo Wang
Abstract： The stability of matrix graphite under neutron irradiation and in corrosive environments is crucial for the
safe operation of molten salt reactors (MSRs). Raman spectroscopy and a slow positron beam were employed
to investigate the effects of He ion irradiation fluences and subsequent annealing on the microstructure and
defects of the matrix graphite. He ions with 500 keV energy and fluences ranging from 1.1 × 1015 ions/cm2
to 3.5 × 1017 ions/cm2 were used to simulate neutron irradiation at 300K. The samples with an irradiation
fluence of 3.5×1016 ions/cm2 were subjected to isochronal annealing at different temperatures (573K, 873 and
1173K) for 3 h. The Raman results revealed that the D peak gradually increased, whereas the intrinsic G peak
decreased with increasing irradiation fluence. At the same irradiation fluence, the D peak gradually decreased,
whereas the intrinsic G peak increased with increasing annealing temperature. Slow positron beam analysis
demonstrated that the density or size of irradiation defects (vacancy type) increased with higher irradiation
fluence, but decreased rapidly with increasing annealing temperature. The Raman spectral analysis of sample
cross sections subjected to high irradiation fluences revealed the emergence of amorphization precisely at the
depth where ion damage was most pronounced, whereas the surface retained its crystalline structure. Raman
and positron annihilation analyses indicated that the matrix graphite exhibited good irradiation resistance to He
ions at 300K. However, vacancy-type defects induced by He ion irradiation exhibit poor thermal stability and
can be easily removed during annealing.
Peer Review Status:Awaiting Review
Subjects: Nuclear Science and Technology >> Nuclear Materials and Techniques submitted time 2023-06-18 Cooperative journals: 《Nuclear Science and Techniques》
Abstract： The ESR signal of black sesame, soybean, peanut irradiated with 0‒9 kGy absorbed dose was determined and the characteristics and intensity were different. The relationship between signal intensity and absorbed doses was also investigated .The results showed that the ESR spectra of irradiated samples inhibited obvious variation compared to those un-irradiated. The dose-response curves of the samples exposed to gamma rays could be described well by binomial function. Besides, the ESR signal intensity was related to the species of samples. This study may be a method for detection of irradiated oilseed by ESR.
Subjects: Physics >> Condensed Matter: Structural, Mechanical and Thermal Properties submitted time 2017-03-26
Abstract：The microstructural features and the effect of Mo addition during incubation period in FeCrNi austenitic alloy were investigated using positron annihilation technique and micro-Vickers Hardness. The electron irradiation, which could induce vacancy defects in material, was performed at room temperature up to the dose of 1.70-4 and 50-4 dpa, respectively. The defect concentration was estimated about 10-4-10-7 though standard trapping model. The added Mo could trap vacancies to form Mo-vacancy complexes, which may suppress the migration and growth of vacancy defects during electron irradiation. In addition, the microstructural evolution during electron radiation resulted in hardening, while the added Mo might to improve the hardening property of the alloy.
Peer Review Status:Awaiting Review
Subjects: Nuclear Science and Technology >> Nuclear Materials and Techniques submitted time 2023-06-18 Cooperative journals: 《Nuclear Science and Techniques》
Abstract： To study cytotoxic effect of heavy ion irradiation in the plateau region, and investigate whether autophagy induced by heavy ion irradiation is cytoprotective, HeLa cells were irradiated with 350 MeV/u carbon ions beams, and the clonogenic survival was analyzed. The results showed that cell survival decreased with increasing doses. It was also found that G2/M-phase cells increased, and the autophagy-related activity was significantly higher than the control. When autophagy was blocked by 3-methyladenine in carbon-ion irradiated cells, G2/M phase arrest and the percentage of apoptosis cells were further elevated, and cell survival decreased significantly, indicating the induction of cytoprotective autophagy by carbon-ion irradiation. Our results demonstrated that autophagy induced by carbon ion irradiation provided a self-protective mechanism in HeLa cells, short-time inhibition of autophagy before carbon-ion irradiation could enhance radiation cytotoxicity in HeLa cells.
Subjects: Nuclear Science and Technology >> Engineering Technology of Fission Reactor submitted time 2023-06-18 Cooperative journals: 《Nuclear Science and Techniques》
Abstract： Tritium self-sustain and circulation is the core problem to use fusion energy peacefully. As the core component of the breeder in-pile irradiation test, the irradiation tritium production device provides irradiation space for breeders' tritium production and release. We take the Li4SiO4 as the research object and design the structure of the irradiation device. We complete the physical parameters computation, the irradiation device safety analysis and the flow field analysis of the breeder refueling, realizing the adjusting of the breeder irradiation temperature and the tritium release temperature window and making the control of gas operational parameters come true. The data could provide reference for breeders’ in-pile irradiation research.
Subjects: Nuclear Science and Technology >> Nuclear Materials and Techniques submitted time 2023-06-18 Cooperative journals: 《Nuclear Science and Techniques》
Abstract： The surface of anatase TiO2 was modified by maleic andydride (MAH) γ radiation. The properties of surface modified TiO2 were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT IR), X-ray photoelectron spectrum (XPS), thermal gravimetric analysis (TGA), as well as transmission electron microscopy (TEM). The results suggest that the MAH anchored on the surface of TiO2 through chemical bonding and the grafting ratio was approximately 2.7%. TEM image revealed that the modified particles had good dispersibility and compatibility with N,N-Dimethylformamide(DMF), which facilitated to hinder the aggregation of TiO2 particles.
Subjects: Physics >> Condensed Matter: Structural, Mechanical and Thermal Properties submitted time 2017-03-26
Abstract：Positron irradiation effects on positronium formation in low-density polyethylene (LDPE), gamma-irradiated LDPE and unplasticized PVC (UPVC) are studied. At least in one of the three different measurements, i.e., prolonged positron annihilation measurement at room temperature, low temperature in darkness and subsequent measurement under light, changes in o-Ps intensity are observed in nonirradiated LDPE and gamma-irradiated LDPE. While in UPVC, change in o-Ps intensity is hardly observable in all the above-mentioned three measurements. Reduction of o-Ps intensity by light indicates that positronium formation via the recombination of a positron and a trapped electron exists in LDPE and gamma-irradiated LDPE. The absence of light bleaching effect, together with the fact that the value of o-Ps intensity in heating and cooling process of a thermal circle is nearly the same, indicates that in UPVC, positronium can not be formed through trapped electron mechanism. This study highlights the speciality of positronium formation in UPVC, positronium is formed exclusively by the recombination of electron-positron pairs with short separations.
Peer Review Status:Awaiting Review
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