表面增强拉曼散射(SERS)技术在农药残留的检测方面具有很大的潜力,但在痕量和定量分析方面仍存在局限性。提出了一种基于Au@4-ATP@Au凸多面纳米颗粒(NCPs-Au@4-ATP@Au)为增强基底的农药检测方法。XRD结果表明,由于探针分子对金前驱的选...表面增强拉曼散射(SERS)技术在农药残留的检测方面具有很大的潜力,但在痕量和定量分析方面仍存在局限性。提出了一种基于Au@4-ATP@Au凸多面纳米颗粒(NCPs-Au@4-ATP@Au)为增强基底的农药检测方法。XRD结果表明,由于探针分子对金前驱的选择性和诱导性,NCPs-Au@4-ATP@Au纳米颗粒与球形金纳米颗粒晶面结构信息有明显差异,具体体现在(200)处的强反射峰。结合扫描电镜与吸收光谱可以确定,NCPs-Au@4-ATP@Au同时具备球形与多面体结构特征。吸收峰较球形金纳米颗粒有明显红移,更加接近激发光波长,这在理论上更有利于SERS信号的增强。实验证明,以表面包覆高指数晶面,同时内嵌4-ATP作为探针分子的NCPs-Au@4-ATP@Au为增强基底,农药多菌灵(CBZ)的检测限(LODs)达到0.66 nmol·L^(-1)。通过对CBZ分子的拉曼与SERS光谱位移分析可以初步确定,CBZ分子是通过NH键和CO键吸附于金纳米颗粒上。Au@4-ATP@Au利用多凸面结构体提高灵敏度的同时,以4-ATP作为定标信号,归一后光谱稳定性和时效性也得到改善。内标峰强度矫正后光谱稳定性的相对标准偏差(relative standard deviation,RSD)低至7.03%,半个月内信号强度仅降低5.87%,RSD为2.94%。结果表明,NCPs-Au@4-ATP@Au提高了SERS在农药检测方面的痕量和定量检测能力,该基底有望推动SERS在实际中的应用。展开更多
This paper develops a numerical criterion for collision detection between robot links and obstacles located in robot workspace. We study the distance function between 3 D convex polyhedra in the sense of p metri...This paper develops a numerical criterion for collision detection between robot links and obstacles located in robot workspace. We study the distance function between 3 D convex polyhedra in the sense of p metric with emphasis being put on two special cases, i.e., p =1 and p =∞. The characteristics of the p distance such as its topological property, Lipschitz continuity and mutual equivalence for different p , etc., are investigated. Furthermore, the algorithms for computing the 1 distance and the ∞ distance are also presented, it is shown either of them can be evaluated by solving a linear programming problem. The results of this paper form a foundation of collision free path planning for robot manipulators.展开更多
文摘表面增强拉曼散射(SERS)技术在农药残留的检测方面具有很大的潜力,但在痕量和定量分析方面仍存在局限性。提出了一种基于Au@4-ATP@Au凸多面纳米颗粒(NCPs-Au@4-ATP@Au)为增强基底的农药检测方法。XRD结果表明,由于探针分子对金前驱的选择性和诱导性,NCPs-Au@4-ATP@Au纳米颗粒与球形金纳米颗粒晶面结构信息有明显差异,具体体现在(200)处的强反射峰。结合扫描电镜与吸收光谱可以确定,NCPs-Au@4-ATP@Au同时具备球形与多面体结构特征。吸收峰较球形金纳米颗粒有明显红移,更加接近激发光波长,这在理论上更有利于SERS信号的增强。实验证明,以表面包覆高指数晶面,同时内嵌4-ATP作为探针分子的NCPs-Au@4-ATP@Au为增强基底,农药多菌灵(CBZ)的检测限(LODs)达到0.66 nmol·L^(-1)。通过对CBZ分子的拉曼与SERS光谱位移分析可以初步确定,CBZ分子是通过NH键和CO键吸附于金纳米颗粒上。Au@4-ATP@Au利用多凸面结构体提高灵敏度的同时,以4-ATP作为定标信号,归一后光谱稳定性和时效性也得到改善。内标峰强度矫正后光谱稳定性的相对标准偏差(relative standard deviation,RSD)低至7.03%,半个月内信号强度仅降低5.87%,RSD为2.94%。结果表明,NCPs-Au@4-ATP@Au提高了SERS在农药检测方面的痕量和定量检测能力,该基底有望推动SERS在实际中的应用。
文摘This paper develops a numerical criterion for collision detection between robot links and obstacles located in robot workspace. We study the distance function between 3 D convex polyhedra in the sense of p metric with emphasis being put on two special cases, i.e., p =1 and p =∞. The characteristics of the p distance such as its topological property, Lipschitz continuity and mutual equivalence for different p , etc., are investigated. Furthermore, the algorithms for computing the 1 distance and the ∞ distance are also presented, it is shown either of them can be evaluated by solving a linear programming problem. The results of this paper form a foundation of collision free path planning for robot manipulators.
基金the National Natural Science Foundation of China under Grant No.60773026(国家自然科学基金)the National High-Tech Research and Development Plan of China under Grant No.2006AA01Z306(国家高技术研究发展计划(863))the National Basic Research Program of China under Grant No.2002CB312102(国家重点基础研究发展计划(973))
