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基于ICRP生物动力学模型的镅急性吸入后在主要源器官中滞留份额计算

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中国辐射卫生 2024年第1期33卷 7-12页

作者：陈倩兰骆志平刘森林中国原子能科学研究院北京102413

目的为了避免超铀核素镅大量吸入造成对关键靶器官的伤害,并为事故后促排或其他辐射防护措施提供依据。方法本研究依据IAEA通用安全导则***-2的内照射事故应急准备与响应通用准则、ICRP当前最新的生物动力学模型及参数,以工作人员急... 详细信息

目的为了避免超铀核素镅大量吸入造成对关键靶器官的伤害,并为事故后促排或其他辐射防护措施提供依据。方法本研究依据IAEA通用安全导则***-2的内照射事故应急准备与响应通用准则、ICRP当前最新的生物动力学模型及参数,以工作人员急性吸入241Am[粒径AMAD 5μm(σ=2.5)]为例建立计算程序,确定关键靶器官为肺部AI区和红骨髓,并确定造成关键靶器官短期吸收剂量的主要源器官为肺部AI区、血液、小梁骨骨表。结果计算出241Am吸入后主要源器官中滞留份额随时间的变化。结论镅吸收入血后从血液中快速转移,不同吸收类别镅在血液中早期滞留份额变化趋势相似,S、M、F类镅在血液中滞留份额峰值出现在0.03 d左右,到约1.7 d时衰减到峰值的一半;镅吸入后在肺部AI区、小梁骨中的早期滞留份额随时间的变化趋势有所不同:S、M类镅在肺部AI区滞留份额随时间变化较小,F类镅从肺部快速被吸收入血;小梁骨中镅,S类在前7 d快速增加,M类主要在前2周逐渐增加,F类在前2 d较快速度增加。

关键词： ICRP 生物动力学模型关键靶器官主要源器官镅滞留

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青藏铁路沿线天然贯穿辐射水平调查

中国辐射卫生 2024年第3期33卷 288-292页

作者：郑国文曲延涛汪传高骆志平陈凌中国原子能科学研究院北京102413 新时代工程咨询有限公司北京102200

目的调查青藏铁路沿线天然贯穿辐射照射水平,并初步评价该铁路从业人员及旅客所受辐射剂量。方法选取青藏铁路沿线15个不同海拔高度的典型测量点以及拉萨到西宁的火车车厢内,利用高气压电离室、碘化钠剂量率仪以及中子周围剂量当量率仪... 详细信息

目的调查青藏铁路沿线天然贯穿辐射照射水平,并初步评价该铁路从业人员及旅客所受辐射剂量。方法选取青藏铁路沿线15个不同海拔高度的典型测量点以及拉萨到西宁的火车车厢内,利用高气压电离室、碘化钠剂量率仪以及中子周围剂量当量率仪对天然贯穿辐射水平进行测量。结果青藏铁路沿线陆地伽马辐射水平范围为21.5~246.6 nGy/h,宇宙射线电离成分辐射水平范围为79.8~225.5 nGy/h,中子辐射水平范围为24.5~101 nSv/h;旅客和乘务人员乘坐一次从拉萨到西宁的火车受到的天然贯穿辐射有效剂量为4.82μSv。结论通过与经验公式比较以及测量方法可靠性验证,证明了测量工作的准确性,初步了解青藏铁路沿线的辐射水平及旅客所受辐射剂量,可为监管部门提供依据。

关键词：青藏铁路天然贯穿辐射宇宙射线电离成分中子陆地γ

Crystalline phase of Y_2O_3 :Eu particles generated in a substrate-free flame process

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Particuology 2011年第1期9卷 24-31页

作者： Bing Guoa Hoon Yim Wonjoong Hwang Matt Nowell zhiping luo Department of Mechanical Engineering Texas A&M University College Station TX 77843 USA EDAX-TSL EDAX Inc. Draper UT84020 USA Microscopy and Imaging Center Texas A&M University College Station TX 77843 USA

In this study, factors affecting the crystal structure of flame-synthesized Y2O3 ：Eu particles were investigated, especially the particle size effect and its interaction with Eu doping concentration, Polydisperse Y2O3：Eu （size range 200 nm to 3μm） powder samples with Eu doping concentrations from 2,5 mol% to 25 mol% were generated in either H2/air or H2/O2 substrate-free flames. The crystal structure of the powder samples was determined by powder X-ray diffraction （XRD）, which was complemented by pho- toluminescence （PL） measurements. Single particle crystal structure was determined by single particle selected area electron diffraction （SAED）, and for the first time, by electron backscatter diffraction （EBSD）. H2/air flames resulted in cubic phase Y2O3：Eu particles with hollow morphology and irregular shapes, Particles from H2/O2 flames had dense and spherical morphology; samples with lower Eu doping concen- trations had mixed cubic/monoclinic phases; samples with the highest Eu doping concentrations were phase-pure monoclinic. For samples generated from H2/02 flames, a particle size effect and its interaction with Eu doping concentration were found： particles smaller than a critical diameter had the monoclinic phase, and this critical diameter increased with increasing Eu doping concentration, These findings suggest that the formation of monoclinic Y2O3：Eu is inevitable when extremely hot substrate-free flames are used, because typical flame-synthesized Y203 ：Eu particle sizes are well below the critical diameter, However, it may be possible to generate particles with dense, spherical morphology and the desired cubic structure by using a moderately high flame temperature that enables fast sintering without melting the particles.

关键词： Flame synthesis Aerosol Size effect Crystal structure Y2O3:Eu Particles

Permeability evolution mechanism and the optimum permeability determination of uranium leaching from low-permeability sandstone treated with low-frequency vibration

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第10期15卷 2597-2610页

作者： Yong Zhao Xiqi Li Lin Lei Ling Chen zhiping luo School of Resource Environment and Safety Engineering University of South ChinaHengyang421001China Department of Nuclear Safety China Institute of Atomic EnergyBeijing102413China

Low-frequency vibrations can effectively improve natural sandstone permeability,and higher vibration frequency is associated with larger ***,the optimum permeability and permeability evolution mechanism for uranium leaching and the relationship between permeability and the change of chemical reactive rate affecting uranium leaching have not been *** solve the above problems,in this study,identical homogeneous sandstone samples were selected to simulate lowpermeability sandstone;a permeability evolution model considering the combined action of vibration stress,pore water pressure,water flow impact force,and chemical erosion was established;and vibration leaching experiments were performed to test the model *** the permeability and chemical reactions were found to simultaneously restrict U6þleaching,and the vibration treatment increased the permeability,causing the U6þleaching reaction to no longer be diffusion-constrained but to be primarily controlled by the reaction *** of the model calculation parameters were further analyzed to determine the permeability evolution mechanism under the influence of vibration and chemical erosion,to prove the correctness of the mechanism according to the experimental results,and to develop a new method for determining the optimum permeability in uranium *** uranium leaching was found to primarily follow a process consisting of(1)a permeability control stage,(2)achieving the optimum permeability,(3)a chemical reactive rate control stage,and(4)a channel flow *** resolution of these problems is of great significance for facilitating the application and promotion of lowfrequency vibration in the CO_(2)+O_(2) leaching process.

关键词： Low-frequency vibration Low-permeability sandstone Uranium migration Permeability evolution mechanism Chemical reactive rate Optimum permeability

Stable Mg- Zn-Y Quasicrystals

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Chinese Physics Letters 1995年第8期12卷 465-468页

作者： luo zhiping ZHANG Shaoqing ZHAO Dongshan TANG Yali SUI Haixin Beijing Institute of Aeronautical Materials Beijing 100095 Beijing Laboratory of Electron Microscopy Academia SinicaP.O.Box 2724Beijing 100080 Zhengzhou Institute of Technology Zhengzhou 450002

By conventional air-cooled casting method,cast ingots with large contents of stable Mg-Zn-Y quasicrystals were *** was shown that most of the quasicrystals are of face-centered icosahedral type,while a few of them belong to simple icosahedral *** quasicrystals were stable during the continuous heating with the temperature below *** oxidizing reactions were observed at high *** is the characteristic of Mg-Zn-Y alloys,which differs from that of A1 base alloys.

关键词： temperature. casting alloys

Microstructure and Tensile Properties of Spray-deposited IC6 Alloy

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Journal of Materials Science & Technology 1998年第2期14卷 143-146页

作者： Mi, Guofa Li, Zhou Tian, Shifan Zhao, Xianguo luo, zhiping Zeng, Songyan Li, Qingchun Inst Aeronaut Mat Beijing 100095 Peoples R China Harbin Inst Technol Sch Mat Sci & Engn Harbin 150001 Peoples R China

The microstructure and mechanical properties of a Ni//3 Al based Ni-Al-Mo superalloy-IC6 which possesses low impurity content and high density by spray deposition technique have been studied. The results indicate that the IC6 alloy has good tensile strength and elongation both at room and intermediate temperatures. (Edited author abstract) 6 Refs.

关键词： Nickel alloys

High-temperature phase transition behavior and magnetocaloric effect in a sub-rapidly solidified La–Fe–Si plate produced by centrifugal casting

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Journal of Materials Science & Technology 2018年第8期34卷 1337-1343页

作者： Zhishuai Xu Yuting Dai Yue Fang zhiping luo Ke Han Changjiang Song Qijie Zhai Hongxing Zheng Laboratory for Microstructures Shanghai UniversityShanghai 200444China State Key Laboratory of Advanced Spedal Steel Shanghai UniversityShanghai 200444China Department of Chemistry and Physics FayetteviUe State UniversityFayettevilleNC28301USA National High Magnetic Field Laboratory Florida State UniversityTaUahasseeFL 32310USA

A sub-rapidly solidified LaFe11.6Si1.4 plate was fabricated directly from liquid by centrifugal casting method. The phase constitution, microstructure and magnetocaloric effect were investigated using backscatter scanning electron microscopy, X-ray diffraction, differential scanning calorimetry and phys- ical property measurement system. When the plate was annealed at 1373 K, rl phase was formed by a solid-state peritectoid reaction. A first-order magnetic phase transition occurred in the vicinity of 188 K, and the effective refrigeration capacities reached 203.5J/kg and 209.7J/kg in plates annealed for I h and 3 h, respectively, under a magnetic field change of 3T. It is suggested that centrifugal casting may become a new approach to prepare high-performance La-Fe-Si magnetocaloric plates for prac- tical applications, which could largely accelerate the formation of rl phase during high-temperature heat-treatment process due to refined and homogeneous honeycombed microstructure.

关键词： La-Fe-Si Magnetocaloric effect Rapid solidification Centrifugal casting Phase transition

Water Distribution and Removal along the Flow Channel in Proton Exchange Membrane Fuel Cells

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Journal of Wuhan University of Technology(Materials Science) 2013年第2期28卷 243-248页

作者：丁刚强 TANG Heqing luo zhiping 涂正凯 PEI Houchang LIU Zhichun LIU Wei College of Chemistry and Chemical Engineering Huazhong University of Science and Technology Power Battery Division Wuhan Institute of Marine Electric Propulsion State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology College of Energy and Power Engineering Huazhong University of Science and Technology

Distribution expressions of total gas pressure and partial water vapor pressure along the channel direction were established based on lumped model by analyzing pressure loss in the channel and gas diffusion in the layer. The mechanism of droplet formation in the flow channel was also analyzed. Effects of the relative humidity, working temperature and stoichiometry on liquid water formation were discussed in detail. Moreover, the force equilibrium equation of the droplet in the flow channel was deduced, and the critical flow velocity for the water droplet removal was also addressed. The experimental results show that the threshold position of the liquid droplet is far from the inlet with the increase of temperature, and it decreases with the increase of the inlet total pressure. The critical flow velocity decreases with the increase of the radius and the working pressure.

关键词： proton exchange membrane fuel cells pressure loss water distribution water removal

MICROSTRUCTURES OF Mg-Zr,Mg-Zn AND Mg-Zn-Zr ALLOYS

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Acta Metallurgica Sinica(English Letters) 1993年第5期6卷 337-342页

作者： luo zhiping ZHANG Shaoqing Institute of Aeronautical Materials,Beijing,China luo zhiping,doctorate student P.O.Box 81-4,Beijing 100095,China

Microstructural studies have been made on the Mg-0.54Zr,Mg-5.68Zn and Mg-5.65Zn-0.50Zr alloys in the as-cast and homogenized *** lenticular plates of {012}twins were found in three *** homogenization,ZrH_2 phase formed in the Mg-0.54Zr *** Mg_7Zn_3 phase of cubic structure with a=1.417 nm distributes at the grain boundaries of the Mg-5.68Zn alloy in the as-cast state and after homogenization,the Mg_7Zn_3 phase dissolves and the MgZn_2 phase *** as-cast Mg-5.65Zn-0.50Zr al- loy consists of MgZn_3 phase and Zn-Zr *** homogenization,the dispersed acicular MgZn_2 phase may precipitate.

关键词： Mg-Zn-Zr alloy phase structure twin