共查询到20条相似文献,搜索用时 8 毫秒
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A. M. Petros'yants 《Atomic Energy》1969,26(2):120-126
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代谢性骨病骨显像特点探讨 总被引:2,自引:0,他引:2
为提高骨显像对临床上各种骨疾患的鉴别诊断能力,本文回顾分析了代谢性骨病在骨显像上的特征表现.临床确诊的142例共6种代谢性骨病:其中甲状旁腺功能亢进症117例;肾性骨病4例;畸形性骨炎16例;成人骨软骨病2例;石骨症2例,脆骨病1例.142例代谢性骨病的骨显像结果可分为四种类型:全身骨摄取显像剂增加(I型);局部骨摄取显像剂增加(Ⅱ型);全身+局部骨摄取显像剂增加(Ⅲ型)和正常骨显像图(Ⅳ型).部分甲旁亢、石骨症、脆骨病和肾性骨病骨显像表现为I型;畸形性骨炎、成人低血磷软骨病和部分甲旁亢骨显像表现为Ⅱ型;表现为I型的代谢骨病患者发生病理性骨折或继发局部骨病变时骨显像表现为Ⅲ型.Ⅳ型骨显像仅发现在早期甲旁亢的患者.各种类型在异常显像骨的部位、骨显像病灶的形状、摄取显像剂的程度等方面均有自身特点,根据这些特点再结合病史及X线结果可有助与骨肿瘤加以区别. 相似文献
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Compared with the isotopes generated by nuclear reactor, the isotopes prepared by accelerator always show high specific activity and short half-life period. And most of such isotopes always were neutron-deficient nuclides, giving β+ or single energy γ ray. As one of the most important methods preparing radionuclides, the preparation of isotopes by accelerator has attracted more and more attention from the beginning of 21th century. The development of the preparation and application of the accelerator isotopes were briefly introduced in China. In addition, the forecast of the accelerator-isotope prospect were drawn. 相似文献
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同位素,包括放射性同位素和稳定同位素,对美国社会和经济发展、科学技术进步做出了重要贡献。本文对美国的主要同位素生产机构、设施和能力,未来需求及满足其未来需求所应采取的措施等几个方面做了简要叙述。 相似文献
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同位素比值是污染源解析的基础,为了探索燃煤污染源解析的可行性,本研究建立煤炭中铅同位素的分析方法。采用灰化-微波消解相结合的方式,将煤样转换为溶液状态,用PB树脂(冠醚类)萃取色层法,将铅和大量基体元素有效分离,用多接收电感耦合等离子体质谱法测定铅同位素比值。利用NIST 981标定天然铅溶液的铅同位素比值,应用建立的分析方法,测定~(208)Pb/~(207)Pb、~(206)Pb/~(207)Pb的同位素比值,相对误差小于0.03%。钠、镁、铝、铁、钛、锰等元素的去污系数均大于400。结果表明,该方法有效、可靠,测定标准煤样(NIST 1635a、NIST 1632d)、山西大同煤样和攀枝花煤样的~(208)Pb/~(207)Pb、~(206)Pb/~(207)Pb同位素比值,精密度均大于0.2%,两地煤样同位素比值变异为6%~10%,初步验证了建立全国煤炭中铅同位素比值背景数据库的可行性。 相似文献
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锂有两种稳定的同位素且在核能工业中都有重要的应用,工业上分离锂同位素的方法为锂汞齐法,但该法需使用大量有毒的汞,对人类健康和环境卫生带来了严重问题,因此寻找一种绿色有效的替代方法势在必行。自冠醚和穴醚合成后,在锂同位素分离上的优良特性使其成为了国内外研究热点,本工作将近40年来冠状化合物在锂同位素分离中的研究成果进行了系统的归类和总结,为该领域的进一步研究提供参考。 相似文献
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Bernard Schaeffer 《Journal of Fusion Energy》2011,30(5):377-381
Bieler of the Rutherford laboratory imagined in 1924 a magnetic attraction equilibrating an electrostatic repulsion between
the protons. Since the discovery of the neutron and the magnetic moments of the nucleons proving that the neutron contains
electric charges, nobody, as far as I know, has tried to apply electromagnetism to the nuclear interaction. As it is well
known, there is an attraction between an electric charge and a neutral conductor. In the deuteron, the positive charge of
the neutron is repelled and the negative charge is attracted by the proton with a net attraction. The repulsion between the
magnetic moments equilibrates the electrostatically induced attraction. The calculated value is −1.6 MeV not too far from
the experimental value (−2.2 MeV). The calculated 7 hydrogen isotopes stay satisfactorily along the experimental isotopic
parabola. No arbitrary fitting parameter is used, only universal physical constants. The electromagnetic theory predicts a
theoretical ratio between nuclear and chemical energies:
\fracmpme a.\frac{m_p}{m_e \alpha}. 相似文献
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为深入了解同位素示踪技术的特点和优势,重点总结了近年来在农业科学相关领域的一些应用研究热点。15N、32P示踪为揭示作物营养元素有效转化机理,创建养分高效利用技术模式提供重要支持。13C、15N示踪在土壤有机碳循环、温室气体减排研究中,凸显了独特优势。14C示踪为我国自主创制的新农用化学物质生态环境影响评价,提供重要技术支撑。稳定性同位素比率、δ13C等同位素指纹技术,为明确农田污染物的环境行为、解析污染源,提供了重要手段;为国家名特优农产品原产地溯源,提供原创的技术性思路。109Cd、65Zn示踪为揭示土壤重金属镉、锌污染环境行为,提供不可或缺的技术支持。环境核素7Be、137Cs示踪在生态系统稳定性研究方面,发挥了不可替代的作用。 相似文献
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《中国原子能科学研究院年报(英文版)》2001,(1)
The purpose of this work is to apply the fully consistent RRPA method to the collective giant resonance of nuclei far from the p-stability line. The isovector giant dipole resonance in Ca isotopes is investigated in the framework of the fully consistent RRPA. The calculations are performed in an effective Lagrangian with a parameter set NL3, which was proposed for satisfactorily describing nuclear ground state properties as well as the isospin giant monopole resonance, i.e. nuclear breathing mode. The response functions of IVGDR for various Ca isotopes are plotted in Fig.1. The solid and dotted curves are full RRPA and unperturbed strengths, respectively. The dashed curves represent the 相似文献