脉冲激光场中金微粒表面温度的探究
关键词:
- 激光光学 /
- 金微粒 /
- 表面温度 /
- 热传导
摘要: 激光照射纳米微粒法是基因转染的一种，其中涉及到的细胞成活率和基因转染率与纳米粒子的光热效应密切相关，且最终依赖于结合体表面所达到的温度。该文作为基因转染的前期工作，旨在能够方便地计算出脉冲激光照射下金粒子的表面温度，设计出激光照射靶的最佳参数，理论上提高转染效率。这里以脉冲激光与金粒子相互作用为研究对象，基于热传导方程，将粒子的吸热过程按照4个距离参数（R ，δ，χfτ，χAuτ）进行分割，并在每个加热区域分析出了表面温度的数学表达式。结果表明在激光功率密度为5×1011 W/cm2，波长为532 nm时，表面温度分析法得到的关于表面温度随金粒子半径变化的曲线趋势与米氏理论数值解析得到的趋势相同，数据点基本吻合。且在3种不同的脉冲持续时间下（30 ns ，30 ps ，30 fs）都得到了证明。另外，表面温度随金粒子半径和脉冲宽度变化的密度图还显示出了获得最大温度的参数关系式R＝2χfτ。因此，依据加热区域的划分，利用表面温度分析的方法可以简便、准确地获得金粒子在激光参数下的表面温度，在理论上设计出了激光与金纳米粒子结合的最佳参数。
The Surface Temperature of Gold Particles in Laser Field
Keywords:
- 激光光学 /
- 金微粒 /
- 表面温度 /
- 热传导
Abstract: The method of nano‐particles by laser irradiation is a kind of gene transfection ,where the in‐volved cell survival rate and gene transfection rate are closely related to the thermal effect of nano‐parti‐cles ,and ultimately depend on the surface temperature of combinations .As the prophase work of gene transfection ,this paper is aimed at calculating the surface temperature of the gold particles in the pulse la‐ser easily ,at designing the best parameter of the laser and gold particles ,and improving the transfection efficiency theoretically .Based on the heat conduction equation ,the pulse laser interaction with gold parti‐cles has been studied and the heat absorption process of the particle has been divided by the four distance parameters(R ,δ, χfτ , χAuτ) .T hen ,the mathematical expressions of surface temperature have been analyzed in each heating area .Results show that when laser power density is 5 × 1011 W/cm2 and the wave‐length is 532nm ,the surface temperature change with gold particle radius have been calculated respectively in two methods of the exact Mie solution and the above‐mentioned analytical method .The data results of two methods are basically the same .In this paper ,laser pulse width were 30ns ,30ps and30fs respectively . At last ,conditions of achieving maximum temperature are analyzed in the density figure about the surface temperature change with gold particle radius and laser pulse width .
下载: