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您的检索式：作者名="Lewis Elfed"
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| 1 | Ultra-high-resolution detection of Pb2+ ions using a black phosphorus functionalized microfiber coil resonator显示文摘A black phosphorus(BP) functionalized optical fiber sensor based on a microfiber coil resonator(MCR) for Pb^2+ ion detection in an aquatic environment is presented and experimentally demonstrated. The MCR-BP sensor is manufactured by winding a tapered microfiber on a hollow rod composed of a low-refractive-index polycarbonate(PC) resin with the BP deposited on the internal wall of the rod. Based on the propagation properties of the MCR, the chemical interaction between the Pb^2+ ions and the BP alters the refractive index of the ambient environment and thus results in a detectable shift in the transmission spectrum. The resonance wavelength moves towards longer wavelengths with an increasing concentration of Pb^2+ ions, and the sensor has an ultra-high detection resolution of 0.0285 ppb(parts per billion). The temperature dependence is 106.95 pm/°C due to the strong thermo-optic and thermal-expansion effect of the low-refractive-index PC resin. In addition, the sensor shows good stability over a period of 15 days. The local pH also influences the sensor, with the resonance wavelength shift increasing as pH approaches a value of 7 but then decreasing as the pH value increases further due to the effect of the BP layer by H^+ and OH-ions. The sensor shows the potential for high-resolution detection of Pb^2+ ions in a liquid environment with the particular advantages of having a simple structure, ease of fabrication,low cost, low loss, and simple interrogation. | YU YIN SHI LI SHUNBIN WANG SHIJIE JIA JING REN GERALD FARRELL ELFED LEWIS PENGFEI WANG | 2019 | Photonics Research2019，7，6： | 2 |
| 2 | Design of a system that uses optical-fiber sensors and neural networks to control a large-scale industrial oven by monitoring the food quality online显示文摘 | O'Farrel Marion Lewis Elfed Flanagan Colin | 2005 | IEEE Sensors Journal2005，5，5： | 1 |
| 3 | 放疗绝对剂量的数学算法模型显示文摘本文提出一种通过物理模型计算放疗过程中每一个组织深度处绝对剂量的算法,它可代替蒙特卡罗仿真的部分工作且耗费时间更少.这个算法是基于对照射野内X射线产生电子的能量注量的积分运算,并考虑了射线的能谱及二次散射线,得到了后向散射对表面剂量的贡献比例,同时得到前向散射、后向散射及原射线剂量贡献的关系.比较了二次光子和二次电子的三维能谱,得出该能谱是粒子注量关于粒子能量和粒子运动方向的函数.为了得到每一深度处的光子注量,计算了有连续能谱的X射线的期望质量衰减系数.上述算法计算得到的绝对剂量与蒙特卡罗方式仿真的结果趋势一致,两者的差异在于算法未考虑高于二次的散射线.最后将算法应用到非均匀模体剂量计算,能准确反映其中剂量分布特点且具有较小的误差. | 谢天赐 张彬 贺泊 李昊鹏 秦壮 钱金钱 石锲铭 Lewis Elfed 孙伟民 | 2021 | 物理学报2021，70，1： | 0 |
| 4 | GEANT4 simulation study of over-response phenomenon of fiber x-ray sensor显示文摘The purpose of this article is to explore the cause of the over-response phenomenon of fiber x-ray sensor.The sensor is based on a length of PMMA fiber,whose end is filled with the scintillation material Gd_(2)O_(2)S:Tb.The Monte Carlo simulation software GEANT4 uses the phase space file provided by the International Atomic Energy Agency(IAEA),by irradiating the fiber x-ray sensor in the water phantom,counting the fluorescence signal of the optical fiber x-ray sensor after propagation through the fiber.In addition,the number of Cerenkov photons propagating through the fiber is also counted.Comparing this article with previous research,we believe that one of the reasons for the over-response of the fiber x-ray sensor is the non-linear response of the deposition energy of the scintillator to the fluorescence.By establishing a region of interest and counting the x-rays in this region,the simulation results show that the counted number of x-rays that may affect the fiber x-ray sensor is the biggest in the area of interest at a water depth of 5 cm.This result is close to the maximum dose point of the experimental and simulated percentage depth dose(PDD) curve of fiber x-ray sensor.Therefore,the second reason of the over-response phenomenon is believed to be fact that the inorganic materials such as Gd_(2)O_(2)S:Tb have larger effective atomic numbers,so the fiber x-ray sensors will cause more collisions with x-ray in a low energy region of 0.1 MeV-1.5 MeV. | 张彬 谢天赐 秦壮 李昊鹏 李松 赵文辉 陈子印 徐军 Elfed Lewis 孙伟民 | 2021 | Chinese Physics B2021，30，4： | 0 |
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