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讨论了新型近距离放射治疗粒子源125I和103Pd的使用,并以美国医学物理学家协会推荐的近距离放射治疗剂量计算草案为依据,利用蒙特卡罗程序MCNP4C模拟国际近距离放射治疗公司(IBt)生产的新型粒子125I源在固体水模型中的剂量计算几何模型;MCNP4C模拟得到的几何水模型可对AAPM工作组43号报道推荐的剂量测定参量如剂量率常数、径向剂量函数和各向异性函数进行精确计算;近距放射治疗源的剂量学特征就可以通过计算这些剂量测定参量得到. 相似文献
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之己 《光电子技术与信息》1998,11(2):8-16
1引言 恶性肿瘤病变的光动力学治疗(PDT)涉及给患者服用光敏剂,服用后光敏药物在肿瘤中达到适当浓度所需要的时间延迟,对病变组织用适宜波长的光进行辐照,高效地激活光敏剂. 相似文献
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It is well known that transportation is the economiclifeline of a country and bridges are the throat of com-munication.At present,there are about5000thou-sands of main highways in China,among which overone third are structurally defective,more or less dam-aged and potentially threatened by functional degrada-tion.Some of the key bridges need to be monitored,e-valuated and maintained,repaired or reinforced.Largeand important bridges are always designed to work formany decades or even longer.Ac… 相似文献
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使用准平行紫外光束仪测定了重庆城北污水处理厂终沉池出水中粪大肠菌群的紫外线响应曲线,验证了常用剂量下紫外线辐照强度与时间的互为倒数关系,并对验证微生物和商业UV消毒反应器紫外线剂量分布模式的选择进行了讨论。结果显示,当进水粪大肠菌群的浓度取3.0×106MPN/L时,与104MPN/L和103MPN/L两个排放标准对应的目标紫外线剂量分别为11.3mJ/cm2和15.8 mJ/cm2,对应的REDMS2分别为28.2 mJ/cm2和40 mJ/cm2。分析发现,当使用等效生物验证剂量(RED)方法确定紫外线消毒系统的处理能力时,进水粪大肠菌群浓度为107MPN/L的取值过于保守,会造成设备处理能力过度富余。 相似文献
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《核标准计量与质量》2011,(1):11
(发布日期:2011-01-07)ISO 27048:2011规定了职业性易受内部放射性物质污染的工人监测数据评估的最低要求。此标准提出了监测数据的标准化解释的程序和假设,以达到可接受的可靠性水平。这些程序使辐射剂量得以量化,以文件证明其符合辐射防护程序和法规文件的要求。对于剂量水平,此标准为程序适用性设定限值;高于该水平时,将应用更复杂的方法。 相似文献
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在天然铀元件厂中,对操作人员的裸露皮肤,特别是眼睛所受的β-γ外照射的吸收剂量很关紧要,但这方面的报道较少。有人曾使用FJ-352A型辐射剂量仪对工作场所进行测量,但结果不理想。这种方法的缺点是:(1)只能测瞬时剂量,代表性差;(2)受现场各种物料的形状、线度及比放射性等因素限制;(3)刻度和计算麻烦,估算困难;(4)虽能直接读出结果,但误差大。我们采用热释光剂量计(TLD)进行测量,弥补了这些缺点。 相似文献
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Polycrystalline powder samples of dysprosium doped Zn(BO2)2 phosphors were prepared by solid state reaction in air at high temperature and characterized by X-ray powder diffraction. The IR, Photoluminescence (PL), diffuse reflectance and three-dimensional (3D) thermoluminescence (TL) emission spectrum after 60^Co gamma ray irradiation were investigated. The characteristic 3D TL emission bands at about 425, 481 and 573 um with a main emission band of around 573 um were attributed to the host emission, 4^F9/2→6H15/2 and F9/2→6^H13/2 f-f transitions of Dy^3+ ions. No emission from Dy^2+ ions was observed in the measurement wavelength range. The TL-dose response of the Zn(BO2)2:Dy polycrystalline powder sample to gamma ray radiation in the range from 1 to 100 Gy at clinical dose levels was almost linear. The experimental results showed that Zn(BO2)2:Dy had potential use as the materials of gamma-ray thermoluminescence dosimeter (TLD) for clinical dosimetry. 相似文献
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