• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The journal of physical chemistry, A. Molecules, spectroscopy, kinetics, environment, & general theory >Slow Infrared Laser Dissociation of Molecular in th Rapid Energy Exchange Limit
【24h】

Slow Infrared Laser Dissociation of Molecular in th Rapid Energy Exchange Limit

机译：快速能量交换极限中分子的慢红外激光解离

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

An improved model for the slow infrared laser photodissociation of large biomolecules is proposed. As has been previously shown by master equation and Monte Carlo calculations, large, laser-heated molecules reach steady-state internal energy distributions that very closely approximate Boltzmann internal energy distributions. By approximating the internal energy distribution of laser-heated molecules as a Boltzmann distribution, one can derive a very simple relationship between the relative laser power experimented by the ions and the ion temperature. This relationship can be substituted into the Arrhenius equation, yielding a new Arrhenius-like relationship for slow laser dissociation. The model presented here is a modified version of the laser dissociation model proposed by Dunbar in 1991 (J. Phys. Chem. A 2000, 104, 3188-3196). Dunbar's model, while making the correct qualitative predictions, significantly underestimates the activation energy of large molecules measured by laser dissociation. The present laser dissociation model differs from the Dunbar model in that stimulated and spontaneous emission at all frequencies is included in the analysis. A significant result of this model is that there is a parameterized relationship between the laser power and the dissociation rate constant and that the parameterization for different classes of polymers can be determined computationally. This new model gives activation energies via CO_2 laser dissociation that are in good agreement with activation energies measured by blackbody infrared radiative dissociation.
机译：提出了一种改进的大分子慢红外激光光解离模型。正如先前由主方程和蒙特卡洛计算所表明的那样，被激光加热的大分子达到的稳态内部能量分布非常接近玻尔兹曼内部能量分布。通过将激光加热分子的内部能量分布近似为玻尔兹曼分布，可以推导离子实验的相对激光功率与离子温度之间的一种非常简单的关系。可以将这种关系代入Arrhenius方程，从而产生新的类似Arrhenius的关系，用于缓慢的激光解离。这里介绍的模型是Dunbar在1991年提出的激光离解模型的修改版本（J. Phys。Chem。A 2000，104，3188-3196）。邓巴的模型在做出正确的定性预测的同时，大大低估了通过激光离解测量的大分子的活化能。本激光解离模型与邓巴模型的不同之处在于分析中包括了所有频率的受激发射和自发发射。该模型的重要结果是，激光功率和解离速率常数之间存在参数化关系，并且可以通过计算确定不同类聚合物的参数化。该新模型通过CO_2激光解离给出活化能，该活化能与通过黑体红外辐射解离测得的活化能高度吻合。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号