A language to simplify computation of differential mobility analyzer response functions

A language for computation of differential mobility analyzer (DMA) response functions is introduced. The language consists of short programming language expressions that evaluate to the size distribution of particles exiting a DMA. The language permits application of the same framework to single and tandem DMA setups. Expressions are derived for calculation of the convolution matrix used in inversion of size distribution data, calculation of the convolution matrix for transit through tandem DMA systems, and calculation of the size and mobility distribution through DMA systems that involve one or multiple DMAs. The contribution of multiply charged particles to the total response distributions can be explicitly resolved. The derived convolution matrix is suitable for inverting scanning mobility particle sizer response functions using standard regularization techniques. Users can modify and substitute any of the convolution terms—comprising the DMA transfer function, detector efficiency, loss rate, and charging efficiencies—to express response functions of nonstandard DMA configurations. Example applications are presented, including classification of particle size, measurement of size-resolved cloud condensation nuclei activity, characterization of hygroscopicity and volatility tandem DMA response functions, and characterization of the dual tandem DMA system for dimer preparation. The source code and examples are shared as free software and are hosted on an online collaborative software development platform that allows for version tracking and crediting contributors. Adoption of the language may facilitate the design and optimization of custom-built systems that involve unique arrangements of DMAs and detectors. Copyright © 2018 The Author(s). Published with license by Taylor & Francis Group, LLC.本文介绍了一种用于计算微分迁移率分析仪（Differential Mobility Analyzer，DMA）响应函数的编程语言。该语言由简短的编程语言表达式构成，可对经DMA流出的颗粒物粒径分布进行求值运算。本语言支持将同一套框架应用于单级DMA装置与串联DMA装置两类场景。 我们推导了可用于三类计算的表达式：一是粒径分布数据反演所需的卷积矩阵计算，二是颗粒物通过串联DMA系统时的卷积矩阵计算，三是包含单台或多台DMA的系统内颗粒物粒径与迁移率分布的计算。多电荷颗粒物对总响应分布的贡献可被显式解析。 所推导得到的卷积矩阵可通过标准正则化技术，实现对扫描迁移率颗粒物粒径谱仪（Scanning Mobility Particle Sizer）响应函数的反演。用户可对卷积项——包含DMA传递函数、探测器效率、损耗率与荷电效率——进行任意修改与替换，以表征非标准DMA配置下的响应函数。 本文展示了多项应用示例，涵盖颗粒物粒径分类、粒径分辨云凝结核活性测量、吸湿性与挥发性串联DMA响应函数表征，以及用于二聚体制备的双级串联DMA系统表征等场景。本研究以免费软件形式开源了源代码与示例程序，并托管于支持版本追踪与贡献者署名的在线协同软件开发平台。 采用该语言可助力包含定制化DMA与探测器排布的专属系统的设计与优化。版权所有© 2018 作者。经Taylor & Francis Group, LLC授权发布。