This work is aimed at running the first IRIS reactor core with mixed thorium dioxide fuel（ThO2-UO2 and ThO2-PuO2）.Calculations are performed by using Dragon 4.0.4 and Citation codes.The results show the multiplicati...This work is aimed at running the first IRIS reactor core with mixed thorium dioxide fuel（ThO2-UO2 and ThO2-PuO2）.Calculations are performed by using Dragon 4.0.4 and Citation codes.The results show the multiplication factor(Keff) for central and peripheral assemblies as a function of burnup.To ensure the proliferation resistance,the value of 235U enrichment is < 20%.The Keff is calculated using Dragon 4.0.4 for a single fuel rod and the model developed to fuel assembly,while the whole core was calculated using Citation code.For a fuel burnup,the use of increased enrichment fuel in the IRIS core leads to high reserve of reactivity,which is compensated with an integral fuel burnable absorber.The self-shielding of boron is in an IRIS reactor fuel.The effect of increased enrichment to the burn-up rates,and burnable poison distribution on the reactor performance,are evaluated.The equipment used in traditional light water reactors is evaluated for designing a small unit IRIS reactor.展开更多
By using the high energy ball milling method, the nanosized ThO 2 powders were obtained. Through mixing powders, sintering and hot swaging processing, a nanocomposite thoriated tungsten cathode was fabricated. The rel...By using the high energy ball milling method, the nanosized ThO 2 powders were obtained. Through mixing powders, sintering and hot swaging processing, a nanocomposite thoriated tungsten cathode was fabricated. The relative density of the nanocomposite material is near 100%. The microstructure of nanocomposite cathode is quite different from that of conventional thoriated tungsten cathode. Most of thoria particles are less than 100?nm in diameter, and distribute on the boundaries of tungsten grains. The nanocomposite cathode shows a much lower arc starting field than that of conventional cathode, which will improve the performance of the cathode significantly.展开更多
BACKGROUND Gastric cancer(GC)is a common type of digestive cancer with high morbidity and mortality rates worldwide.Considerable effort has been expended in understanding the mechanism of GC development and metastasis...BACKGROUND Gastric cancer(GC)is a common type of digestive cancer with high morbidity and mortality rates worldwide.Considerable effort has been expended in understanding the mechanism of GC development and metastasis.The current study therefore explores the involvement of microRNAs in the regulation of GC progression.AIM To explore the expression and function of miR-30e-3p in GC development.METHODS MiR-30e-3p was found to be downregulated in GC,with low levels thereof predicting poor outcomes among patients with GC.Functionally,we revealed that miR-30e-3p suppressed cell growth and metastatic behaviors of GC cells.Bioinformatics analysis predicted that THO complex 2(THOC2)was a direct target of miR-30e-3p,and the interaction between miR-30e-3p and THOC2 was further validated by a luciferase reporter assay.RESULTS Our findings revealed that knockdown of THOC2 inhibited the growth and metastatic behaviors of GC cells.After investigating signaling pathways involved in miR-30e-3p regulation,we found that the miR-30e-3p/THOC2 axis regulated the PI3K/AKT/mTOR pathway in GC.CONCLUSION Our findings suggest the novel functional axis miR-30e-3p/THOC2 is involved in GC development and progression.The miR-30e-3p/THOC2 axis could be utilized to develop new therapies against GC.展开更多
This paper presents a study on the process engineering aspects of relevance to the industrial implementation of ThO2 and (Th, U)O2 mixed oxide (MOX) pellet type fuel manufacturing. The paper in particular focuses on t...This paper presents a study on the process engineering aspects of relevance to the industrial implementation of ThO2 and (Th, U)O2 mixed oxide (MOX) pellet type fuel manufacturing. The paper in particular focuses on the recycling of thoria based fuel production scrap which is an economically important component in the fuel manufacturing process. The thoria based fuels are envisaged for Advanced Heavy Water Reactor (AHWR) and other reactors important to the Indian Nuclear Power Programme. A process was developed for recycling the chemically clean, off-specification and defective sintered ThO2 and (Th, U)O2 MOX nuclear fuel pellets. ThO2 doesn’t undergo oxidation or reduction and thus, more traditional methods of recycling are impractical. The integrated process was developed by combining three basic approaches of recycling namely mechanical micronisation, air oxidation (for MOX) and microwave dissolution-denitration. A thorough investigation of the influence of several variables as heating method, UO2 content, fluoride and polyvinyl alcohol (PVA) addition during microwave dissolution-denitration was recorded on the product characteristics. The suitability evaluation of the recycled powder for re-fabrication of the fuel was carried out by analyzing the particle size, BET specific surface area, phase using XRD, bulk density and impurities. The physical and chemical properties of recycled powder obtained from the sintered (Th1-y, Uy)O2 (y;0 - 30 wt%) pellets advocate 100% utilisation for fuel re-fabrication. Recycled ThO2 by integrated process showed distinctly high sinterability compared to standard powder evaluated in terms of surface area and particle size.展开更多
文摘This work is aimed at running the first IRIS reactor core with mixed thorium dioxide fuel（ThO2-UO2 and ThO2-PuO2）.Calculations are performed by using Dragon 4.0.4 and Citation codes.The results show the multiplication factor(Keff) for central and peripheral assemblies as a function of burnup.To ensure the proliferation resistance,the value of 235U enrichment is < 20%.The Keff is calculated using Dragon 4.0.4 for a single fuel rod and the model developed to fuel assembly,while the whole core was calculated using Citation code.For a fuel burnup,the use of increased enrichment fuel in the IRIS core leads to high reserve of reactivity,which is compensated with an integral fuel burnable absorber.The self-shielding of boron is in an IRIS reactor fuel.The effect of increased enrichment to the burn-up rates,and burnable poison distribution on the reactor performance,are evaluated.The equipment used in traditional light water reactors is evaluated for designing a small unit IRIS reactor.
文摘By using the high energy ball milling method, the nanosized ThO 2 powders were obtained. Through mixing powders, sintering and hot swaging processing, a nanocomposite thoriated tungsten cathode was fabricated. The relative density of the nanocomposite material is near 100%. The microstructure of nanocomposite cathode is quite different from that of conventional thoriated tungsten cathode. Most of thoria particles are less than 100?nm in diameter, and distribute on the boundaries of tungsten grains. The nanocomposite cathode shows a much lower arc starting field than that of conventional cathode, which will improve the performance of the cathode significantly.
基金Supported by National Natural Science Foundation of China,No.81860442Ningxia Natural Science Foundation Project,No.2022AAC03525.
文摘BACKGROUND Gastric cancer(GC)is a common type of digestive cancer with high morbidity and mortality rates worldwide.Considerable effort has been expended in understanding the mechanism of GC development and metastasis.The current study therefore explores the involvement of microRNAs in the regulation of GC progression.AIM To explore the expression and function of miR-30e-3p in GC development.METHODS MiR-30e-3p was found to be downregulated in GC,with low levels thereof predicting poor outcomes among patients with GC.Functionally,we revealed that miR-30e-3p suppressed cell growth and metastatic behaviors of GC cells.Bioinformatics analysis predicted that THO complex 2(THOC2)was a direct target of miR-30e-3p,and the interaction between miR-30e-3p and THOC2 was further validated by a luciferase reporter assay.RESULTS Our findings revealed that knockdown of THOC2 inhibited the growth and metastatic behaviors of GC cells.After investigating signaling pathways involved in miR-30e-3p regulation,we found that the miR-30e-3p/THOC2 axis regulated the PI3K/AKT/mTOR pathway in GC.CONCLUSION Our findings suggest the novel functional axis miR-30e-3p/THOC2 is involved in GC development and progression.The miR-30e-3p/THOC2 axis could be utilized to develop new therapies against GC.
文摘This paper presents a study on the process engineering aspects of relevance to the industrial implementation of ThO2 and (Th, U)O2 mixed oxide (MOX) pellet type fuel manufacturing. The paper in particular focuses on the recycling of thoria based fuel production scrap which is an economically important component in the fuel manufacturing process. The thoria based fuels are envisaged for Advanced Heavy Water Reactor (AHWR) and other reactors important to the Indian Nuclear Power Programme. A process was developed for recycling the chemically clean, off-specification and defective sintered ThO2 and (Th, U)O2 MOX nuclear fuel pellets. ThO2 doesn’t undergo oxidation or reduction and thus, more traditional methods of recycling are impractical. The integrated process was developed by combining three basic approaches of recycling namely mechanical micronisation, air oxidation (for MOX) and microwave dissolution-denitration. A thorough investigation of the influence of several variables as heating method, UO2 content, fluoride and polyvinyl alcohol (PVA) addition during microwave dissolution-denitration was recorded on the product characteristics. The suitability evaluation of the recycled powder for re-fabrication of the fuel was carried out by analyzing the particle size, BET specific surface area, phase using XRD, bulk density and impurities. The physical and chemical properties of recycled powder obtained from the sintered (Th1-y, Uy)O2 (y;0 - 30 wt%) pellets advocate 100% utilisation for fuel re-fabrication. Recycled ThO2 by integrated process showed distinctly high sinterability compared to standard powder evaluated in terms of surface area and particle size.
