Journal of Aerosol Science最新文献_第8页

Screen diffusion battery method for measuring the size distribution of radioactive aerosol employing multi-layer perception (MLP) neural network 采用多层感知（MLP）神经网络测量放射性气溶胶尺寸分布的屏幕扩散电池方法

IF 3.9 3区环境科学与生态学 Q2 ENGINEERING, CHEMICAL

Journal of Aerosol Science

Pub Date : 2025-06-28 DOI: 10.1016/j.jaerosci.2025.106644

Hao Wang , Fei Zhou , Lele Zhong , Fa Zhong , Xiaotong Chen , Junxia Guo , Zhenzhong Zhang

The precise characterization of the size distribution of radioactive aerosol particles is essential for environmental radiation protection. The screen diffusion battery (SDB) method has been extensively utilized for the sizing of radioactive aerosols. Nevertheless, the accurate and rapid inversion remains a significant challenge within this methodology. This study proposes several multilayer perceptron neural network models to tackle this issue. The performance and applicability of models were assessed using simulated and laboratory measurement data. Results showed that the model achieved accuracy of above 89 % at the error noise level of 10 % in the peak shape classification task. For unimodal distribution parameters, the MAPE (Mean Absolute Percentage Error) of AMD (Activity Median Diameter) and

σ_{g}

(GSD, Geometric Standard Deviation) were maintained below 1.5 % and 3.4 % at noise level of 10 %. For bimodal distribution parameters, the MAPE of all parameters were below 10.5 % at noise of 10 %. These results demonstrate the model's exceptional predictive accuracy and robust noise immunity. Comparison results in radon chamber showed a good linear correlation between AMD (obtained by the SDB system using MLP) and CMD (Count Median Diameter, measured by SMPS) with R² of 0.888, verifying the practical measurement capability of MLP method. The prediction results can be generated almost instantaneously in the millisecond range, which presents potential for real-time and large-scale measurements. Moreover, compared with the conventional method, this MLP method does not require manual selection of initial iteration parameters and will not produce unstable oscillating solutions. These findings can significantly enhance the efficiency and reliability of radioactive aerosol size distribution analysis, supporting improved environmental monitoring, radiation risk assessment and safety protocols in nuclear facilities.

准确表征放射性气溶胶粒子的大小分布对环境辐射防护至关重要。筛网扩散电池（SDB）方法已被广泛应用于放射性气溶胶的分级。然而，准确和快速的反演仍然是该方法的一个重大挑战。本研究提出了几个多层感知器神经网络模型来解决这个问题。利用模拟和实验室测量数据对模型的性能和适用性进行了评估。结果表明，该模型在峰形分类任务中，在误差噪声水平为10%的情况下，准确率达到89%以上。对于单峰分布参数，在噪声水平为10%时，AMD（活动中位直径）和σg（几何标准差）的MAPE（平均绝对百分比误差）分别保持在1.5%和3.4%以下。对于双峰分布参数，在噪声为10%时，所有参数的MAPE均小于10.5%。结果表明，该模型具有良好的预测精度和抗噪声能力。氡室对比结果显示，用MLP法测定的SDB系统得到的AMD与用SMPS法测定的CMD呈良好的线性相关，R2为0.888，验证了MLP法测量的实用能力。预测结果几乎可以在毫秒范围内立即生成，这为实时和大规模测量提供了潜力。此外，与传统方法相比，该方法不需要人工选择初始迭代参数，不会产生不稳定的振荡解。这些发现可以显著提高放射性气溶胶粒径分布分析的效率和可靠性，为改进核设施的环境监测、辐射风险评估和安全规程提供支持。

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引用次数: 0

Optimizing dry powder inhaler for laryngopharyngeal reflux: Effects of particle size and breathing technique 优化干粉吸入器用于喉部反流：颗粒大小和呼吸技术的影响

IF 3.9 3区环境科学与生态学 Q2 ENGINEERING, CHEMICAL

Journal of Aerosol Science

Pub Date : 2025-06-23 DOI: 10.1016/j.jaerosci.2025.106641

Shamudra Dey , Aditya Jadcherla , Nikki Johnston , Jonathan M. Bock , Guilherme J.M. Garcia

Dry powder inhalers (DPIs) were designed to treat lung diseases, but are now being repurposed to address laryngopharyngeal reflux, a condition with no effective treatment. This study assessed how particle size and breathing technique affect DPI deposition on the laryngopharynx using computational fluid dynamics (CFD). Time-dependent airflow and particle transport simulations were performed using the

k - ω

turbulence model on a 3-dimensional airway model of a healthy adult. Regional doses were estimated for sinusoidal breathing profiles with different durations (short vs. long inhalation) and depths (shallow vs. forceful inhalation). Three DPIs were simulated assuming log-normal particle size distributions with mass median aerodynamic diameters

(d_{50})

of 3 μm (DPI-1), 10 μm (DPI-2), or 50 μm (DPI-3) representing commercially available DPIs (DPI-1 and DPI-3) and a theoretical DPI optimized for laryngopharyngeal deposition (DPI-2). Particle size was the dominant factor with laryngopharyngeal doses of 5.3%, 20.3%, and 2.2% of the emitted dose for DPI-1, DPI-2, and DPI-3, respectively, with a normal inhalation (30L/min, 2s inhalation). Inhalation duration had a negligible impact on laryngopharyngeal dose for DPI-1 (short inhalation: 6.2%, long inhalation: 4.9%), DPI-2 (short inhalation: 20.6%, long inhalation: 20.3%) and DPI-3 (short inhalation: 1.9%, long inhalation: 2.3%). Similarly, inhalation depth had a negligible impact on the laryngopharyngeal dose for DPI-1 (shallow inhalation: 5.3%, medium inhalation: 5.8%, forceful inhalation: 6.5%), DPI-2 (shallow inhalation: 20.3%, medium inhalation: 20.0%, forceful inhalation: 21.4%) and DPI-3 (shallow inhalation: 2.2%, medium inhalation: 2.0%, forceful inhalation: 2.2%). In summary, our simulations suggest that particle size affects the laryngopharyngeal dose more significantly than the breathing technique with a mass median aerodynamic diameter of

d_{50} = 10 μ m

being predicted to maximize drug delivery to the laryngopharynx. Further studies are needed to validate these findings in larger cohorts.

干粉吸入器（dpi）被设计用于治疗肺部疾病，但现在被重新用于治疗喉部反流，这是一种没有有效治疗方法的疾病。本研究利用计算流体动力学（CFD）评估了颗粒大小和呼吸技术对喉部DPI沉积的影响。采用k−ω湍流模型对健康成人气道三维模型进行了随时间变化的气流和颗粒输运模拟。对不同持续时间（短吸入与长吸入）和深度（浅吸入与强吸入）的正弦呼吸谱进行区域剂量估计。采用对数正态分布对3种DPI进行了模拟，其质量中值气动直径（d50）分别为3 μm （DPI-1）、10 μm （DPI-2）和50 μm (DPI-3)，分别代表了市售DPI （DPI-1和DPI-3）和针对咽部沉积优化的理论DPI （DPI-2）。DPI-1、DPI-2和DPI-3在正常吸入（30L/min，吸入2s）的情况下，喉部剂量分别占放射剂量的5.3%、20.3%和2.2%。吸入时间对DPI-1（短吸入：6.2%，长吸入：4.9%）、DPI-2（短吸入：20.6%，长吸入：20.3%）和DPI-3（短吸入：1.9%，长吸入：2.3%）的喉咽部剂量影响可忽略不计。同样，吸入深度对DPI-1（浅吸入：5.3%，中吸入：5.8%，强力吸入：6.5%）、DPI-2（浅吸入：20.3%，中吸入：20.0%，强力吸入：21.4%）和DPI-3（浅吸入：2.2%，中吸入：2.0%，强力吸入：2.2%）的喉咽部剂量的影响可以忽略不计。综上所述，我们的模拟表明，颗粒大小对喉部剂量的影响比呼吸技术更显著，预测质量气动中值直径为d50=10μm时，可以最大限度地将药物输送到喉部。需要进一步的研究在更大的队列中验证这些发现。

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引用次数: 0

Performance investigation of machine learning for optical modeling of black carbon aerosols with different coatings and humidities 机器学习在不同涂层和湿度下黑碳气溶胶光学建模中的性能研究

IF 3.9 3区环境科学与生态学 Q2 ENGINEERING, CHEMICAL

Journal of Aerosol Science

Pub Date : 2025-06-22 DOI: 10.1016/j.jaerosci.2025.106639

Donghui Zhou , Jia Liu , Jinbao Han , Jianfei Luo , Bo Yin

Optical properties of black carbon (BC) aerosols are essential for assessing atmospheric radiation and climate change, but fast and accurate optical calculation for BC with complex structures is still a challenge. In this study, a quick optical modeling method for BC coated by different materials under various humidities is developed based on the multiple-sphere T-matrix (MSTM) simulation and support-vector-machine (SVM) algorithm. The typical closed-cell, coated-aggregate, and partially-coated BC models with BC monomers ranging from 50 to 2000 and BC volume fractions ranging from 0.05 to 0.70 are employed, and the relative errors (REs) and determination coefficients (R²) are used to investigate the prediction performance of optical properties based on SVM. Results show that the SVM predicted optical properties, such as optical efficiency, asymmetry factor, single scattering albedo, and lidar ratio, overall agree well with the properties simulated using MSTM. The prediction performance could be influenced by coating structure and morphological parameters, most of the values of REs and R² were smaller than about 20 % and larger than about 0.85, respectively. The relative humidities (RHs) and coating materials slightly deteriorate the performance of SVM. With RHs increasing from 0 % to 95 %, or the coatings become non-absorbing organic carbon (OC) and brown carbon (BrC), the largest REs increase to over 30 %, while most of the R² is still larger than 0.85. This study presented a promising optical modeling method for BC aerosols, and it could be further improved with the development of machine learning.

黑碳气溶胶的光学性质是评估大气辐射和气候变化的基础，但对结构复杂的黑碳气溶胶进行快速准确的光学计算仍然是一个挑战。本研究基于多球t矩阵（MSTM）模拟和支持向量机（SVM）算法，提出了一种不同湿度下不同材料涂层BC的快速光学建模方法。采用BC单体为50 ~ 2000，BC体积分数为0.05 ~ 0.70的典型闭孔、包覆聚集体和部分包覆BC模型，利用相对误差（REs）和决定系数（R2）研究了基于SVM的光学性质预测性能。结果表明，SVM预测的光效率、不对称系数、单散射反照率和激光雷达比等光学特性与MSTM模拟的光学特性总体上吻合较好。预测性能受涂层结构和形态参数的影响，大部分REs和R2值分别小于约20%和大于约0.85。相对湿度（RHs）和涂层材料对支持向量机性能有轻微影响。随着RHs从0%增加到95%，或者涂层变成非吸收性有机碳（OC）和棕碳（BrC），最大的REs增加到30%以上，但大部分R2仍大于0.85。本研究提出了一种很有前途的BC气溶胶光学建模方法，并且可以随着机器学习的发展进一步改进。

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引用次数: 0

A direct and theoretically consistent method for the calculation of the settling speed of prolate spheroidal particles in the atmosphere 一种计算长球状粒子在大气中沉降速度的直接和理论上一致的方法

IF 3.9 3区环境科学与生态学 Q2 ENGINEERING, CHEMICAL

Journal of Aerosol Science

Pub Date : 2025-06-22 DOI: 10.1016/j.jaerosci.2025.106613

Sylvain Mailler , Sotirios Mallios

We propose a new method for calculating the settling speed of aerosol particles with prolate shape in the atmosphere. This method takes into account the known theoretical results on the speed–force relationships for prolate spheroids moving in a fluid, and the results in Mallios et al. (2021) regarding the orientation of prolate particles settling in the atmosphere. Unlike other studies, we focus not on the resistance problem (calculating the aerodynamic force as a function of speed) but on the mobility problem (calculate terminal velocity as a function of the external force). The result of this approach is a set of equations that permit to directly calculate the settling speed of a prolate particle in the atmosphere as a function of its shape and characteristics, which is a very important quantity in atmospheric science since the settling speed of a falling particle is a key factor to determine its lifetime in the atmosphere. With this approach, we show that the settling speed is reduced by up to 20% for particles with aspect ratio 4 compared to same-volume spheres. We compare the results of the present study to CFD results of Sanjeevi et al. (2022) and to laboratory measurements of Bhowmick et al. (2024), the latter comparison showing that the estimates for settling speed from our method is within

\pm 5 %

compared to the measured value. Finally, since calculating the terminal speed of settling particles is an important issue in atmospheric modeling, we provide a Fortran module implementing the method described in the present study.

提出了一种计算长形气溶胶粒子在大气中沉降速度的新方法。该方法考虑了关于在流体中运动的长形球体的速度-力关系的已知理论结果，以及Mallios等人（2021）关于在大气中沉降的长形颗粒方向的结果。与其他研究不同，我们关注的不是阻力问题（计算作为速度函数的气动力），而是机动性问题（计算作为外力函数的终端速度）。这种方法的结果是一组方程，可以直接计算出一个长波粒子在大气中的沉降速度作为其形状和特性的函数，这是大气科学中一个非常重要的量，因为下落粒子的沉降速度是决定其在大气中寿命的关键因素。通过这种方法，我们发现与相同体积的球体相比，长径比为4的颗粒的沉降速度降低了20%。我们将本研究的结果与Sanjeevi et al.（2022）的CFD结果以及Bhowmick et al.（2024）的实验室测量结果进行了比较，后者的比较表明，我们的方法估计的沉降速度与实测值相比在±5%以内。最后，由于计算沉降粒子的终端速度是大气模拟中的一个重要问题，我们提供了一个Fortran模块来实现本研究中描述的方法。

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引用次数: 0

Announcement of the 2024 Journal of Aerosol Science Excellence in Research Award Recipient 宣布2024年气溶胶科学杂志卓越研究奖获得者

IF 3.9 3区环境科学与生态学 Q2 ENGINEERING, CHEMICAL

Journal of Aerosol Science

Pub Date : 2025-06-21 DOI: 10.1016/j.jaerosci.2025.106640

Chris Hogan (Editor-in-Chief, Journal of Aerosol Science)

引用次数: 0

Stochastic asymmetric bronchial tree models for population-scale variability in dosimetry 剂量学中种群尺度变异性的随机不对称支气管树模型

IF 3.9 3区环境科学与生态学 Q2 ENGINEERING, CHEMICAL

Journal of Aerosol Science

Pub Date : 2025-06-20 DOI: 10.1016/j.jaerosci.2025.106622

Debjit Kundu, Mahesh V. Panchagnula

Pulmonary drug delivery has emerged as a preferred mode of drug administration due to its high effectiveness and reduced side effects compared to other methods. Drugs delivered in this manner can be classified into two classes. Some drugs target the lung tissue and are absorbed in the upper airways. Others aim to reach the deep lung, where they are absorbed into the bloodstream to produce systemic effects elsewhere in the body. The efficacy of drug delivery for both would depend on the regional deposition fraction. Various factors such as particle size, inhalation rate, etc. influence the deposition outcomes. More importantly, the trajectories of inhaled particles depend on the unique geometry of each person’s respiratory tract. Variation in lung anatomy is one of the main reasons why different people respond to inhaled medications differently. In addition, several diseases modify the geometry of the airways, leading to altered particle deposition patterns. Therefore, understanding and predicting regional deposition patterns of inhaled drugs becomes crucial for optimizing drug delivery strategies. To that end, we have developed a stochastic asymmetric multi-path model of the human airways. The tracheobronchial airways were generated based on Hess-Murray’s law and stochastic asymmetric branching. Symmetric and alveolated acinar sub-trees were attached to the terminal bronchioles. Through Monte-Carlo simulations, we report the extent, distribution and inter-subject variability in inhaled particle deposition as a function of several key parameters - branching asymmetry, particle size, breathing rate and bronchoconstriction. We show how particle size influences the deposition of particles, how asymmetry generally reduces deposition (barring certain exceptions) and how bronchoconstriction reduces deposition in the deep lung while increasing it in the upper airways. These insights will prove useful in determining drug dosages as well as design and choice of delivery devices such as inhalers and nebulizers.

与其他方法相比，肺给药因其高效且副作用小而成为首选的给药方式。以这种方式递送的药物可分为两类。有些药物以肺组织为靶点，在上呼吸道被吸收。另一些则旨在到达肺部深处，在那里它们被血液吸收，在身体其他部位产生全身效应。两种药物的递送效果取决于区域沉积分数。颗粒大小、吸入速率等因素影响沉积效果。更重要的是，吸入颗粒的轨迹取决于每个人呼吸道的独特几何形状。肺解剖结构的差异是不同人对吸入药物反应不同的主要原因之一。此外，一些疾病改变气道的几何形状，导致颗粒沉积模式改变。因此，了解和预测吸入药物的区域沉积模式对于优化药物递送策略至关重要。为此，我们开发了一个人类气道的随机非对称多路径模型。气管支气管是基于Hess-Murray定律和随机不对称分支生成的。末端细支气管上附着对称的泡状腺泡亚树。通过蒙特卡罗模拟，我们报告了吸入颗粒沉积的程度、分布和主体间变异性作为几个关键参数的函数-分支不对称、颗粒大小、呼吸频率和支气管收缩。我们展示了颗粒大小如何影响颗粒的沉积，不对称如何通常减少沉积（排除某些例外）以及支气管收缩如何减少深肺沉积而增加上呼吸道沉积。这些见解将有助于确定药物剂量，以及设计和选择吸入器和雾化器等输送装置。

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引用次数: 0

Direct inversion for bidimensional distributions of aerosol characteristics 气溶胶特征二维分布的直接反演

IF 3.9 3区环境科学与生态学 Q2 ENGINEERING, CHEMICAL

Journal of Aerosol Science

Pub Date : 2025-06-20 DOI: 10.1016/j.jaerosci.2025.106636

Timothy A. Sipkens, Joel C. Corbin

Aerosol classifiers allow particle populations to be described in terms of mass, mobility diameter, or aerodynamic diameter distributions. When this classification is combined with a second layer of classification, a bidimensional distribution can be retrieved that provides additional insights into the distribution of aerosol properties. Bidimensional distributions are often transformed from extensive quantities related to the measurement (e.g., particle mass) to intensive ones that provide more intuitive insights of particle morphology (e.g., effective density or black-carbon mass fraction). Further, most extensive properties are highly correlated with one another (e.g., particle mass and mobility diameter). This complicates inversion, resulting in retrieved distributions that are considerably broader than the true distribution. In this work, we show that these problems can be solved using a single analysis step to compute distributions-of-interest, phrased in terms of intensive properties. This yields a direct inversion scheme that (1) avoids the need for post-processing to retrieve common distributions-of-interest; (2) reduces the correlation between the aerosol properties for which the bidimensional distribution is defined; (3) makes regularization easier and more objective; and (4) improves the minimum resolvable distribution width by up to 96 %. The approach is demonstrated using both simulated distributions (phantoms) and experimental data.

气溶胶分类器允许根据质量、迁移直径或空气动力学直径分布来描述粒子群。当这种分类与第二层分类相结合时，可以检索到二维分布，从而对气溶胶特性的分布提供额外的见解。二维分布通常从与测量相关的广泛数量（例如，粒子质量）转变为提供更直观的粒子形态见解的密集数量（例如，有效密度或黑碳质量分数）。此外，大多数广泛的性质彼此之间高度相关（例如，粒子质量和迁移率直径）。这使反演变得复杂，导致检索到的分布比真实分布宽得多。在这项工作中，我们表明，这些问题可以使用单个分析步骤来解决，以密集性质为术语来计算兴趣分布。这产生了一种直接的反演方案，它(1)避免了对检索公共兴趣分布的后处理的需要；(2)降低了定义了二维分布的气溶胶特性之间的相关性；(3)使规范化更容易、更客观；(4)将最小可分辨分布宽度提高了96%。该方法使用模拟分布（幻影）和实验数据进行了演示。

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引用次数: 0

Investigation of the morphology and optical properties of graphene oxide for online diagnostics 用于在线诊断的氧化石墨烯的形态和光学性质的研究

IF 3.9 3区环境科学与生态学 Q2 ENGINEERING, CHEMICAL

Journal of Aerosol Science

Pub Date : 2025-06-18 DOI: 10.1016/j.jaerosci.2025.106637

Horace I. Looi , Halil I. Yazici , Joel C. Corbin , Rym Mehri , Timothy A. Sipkens , Kyle J. Daun

Graphene oxide (GO) particles have a wide and growing range of applications. They may also be converted to reduced graphene oxide (rGO) particles, which are increasingly used in energy storage devices like batteries and supercapacitors. However, the downstream functionality of GO and rGO particles depends strongly on their morphology, which is highly variable depending on the synthesis process. Here, we report morphological and optical properties for GO particles in the aerosol phase. These include the mobility diameter, effective density (0.93 ± 0.06 g/cm³), mass–mobility exponent (2.97 ± 0.06), Angstrom absorption exponent (2.48 between 370 nm and 950 nm), mass absorption cross-section (0.99 ± 0.22 m² g⁻¹), and mass scattering cross-section. Although this study reports measurements on re-aerosolized GO powder, the demonstrated techniques and measured properties serve as a foundation for in-reactor optical diagnostics that may allow for online control of the synthesis processes enabling the ability to control and characterize the functionality of downstream particles

氧化石墨烯（GO）颗粒具有广泛且不断增长的应用范围。它们也可以转化为还原氧化石墨烯（rGO）颗粒，这种颗粒越来越多地用于电池和超级电容器等储能设备。然而，氧化石墨烯和还原氧化石墨烯颗粒的下游功能在很大程度上取决于它们的形态，这取决于合成过程。在这里，我们报告了氧化石墨烯颗粒在气溶胶相的形态和光学性质。包括迁移率直径、有效密度（0.93±0.06 g/cm3）、质量迁移率指数（2.97±0.06）、埃吸收指数（2.48）、质量吸收截面（0.99±0.22 m2 g−1）和质量散射截面。尽管本研究报告了对再雾化氧化石墨烯粉末的测量，但所展示的技术和测量的特性可作为反应器内光学诊断的基础，可以在线控制合成过程，从而能够控制和表征下游颗粒的功能

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引用次数: 0

In-vitro visualization of aerosol deposition by laser-induced fluorescence in a human airway model 激光诱导荧光在人体气道模型中气溶胶沉积的体外可视化

IF 3.9 3区环境科学与生态学 Q2 ENGINEERING, CHEMICAL

Journal of Aerosol Science

Pub Date : 2025-06-16 DOI: 10.1016/j.jaerosci.2025.106634

Stefanie Gürzing , Anja Lena Thiebes , Christian Gabriel Cornelissen , Stefan Jockenhoevel , Manuel Reddemann

This study presents the first in-vitro visualization of aerosol deposition from the trachea up to the 10th bifurcation in a transparent airway model. The airway model simulates a representative respiratory tract of the left lower lobe and consists of all 23 generations of a human lung. Laser- induced fluorescence (LIF) was used to investigate the temporal and spatial deposition behavior of aerosols generated by a jet nebulizer along the representative airway. The in-situ measured LIF signal correlates to the amount of deposited aerosol during spontaneous breathing. By the means of LIF-image post-processing the temporal course of the LIF signal in each of the first eight bifurcations is correlated to the main aerosol deposition mechanisms, i.e. inertial impaction and gravitational settling, in the conductive airways. Depending on the time point in the respiratory cycle either one of both deposition mechanisms dominates the current aerosol deposition. The spatial analysis over eight subsequent bifurcations shows the diminishing influence of the inertial deposition mechanism over deeper bifurcations. Further, the duration of gravitational settling decreases over the bifurcations depending on the accompanying airway diameters of each bifurcation. The introduction of the dimensionless Froude number allows the comparison of the measured aerosol deposition to existing research and demonstrates that the proposed threshold limit in literature of Froude <5 matches well to the gravitational settling regime observed in the transparent airway. For Froude >5 mainly the inertial impaction is observed as mechanism for aerosol deposition in this set-up. An error analysis is performed for evaluating the influence of the low relative humidity of the inhaled air on the aerosol evaporation and deposition. This feasibility study shows the capability of the measurement method in combination with the airway model to resolve the aerosol deposition up to the eighth bifurcation. In future, this analysis should be extended to higher airway generations by microscopic LIF imaging to evaluate the deposition mechanisms in all 23 generations of the transparent airway model.

本研究首次展示了透明气道模型中从气管到第10分岔的气溶胶沉积的体外可视化。该气道模型模拟了左下叶的代表性呼吸道，由人类肺的所有23代组成。采用激光诱导荧光（LIF）研究了喷射雾化器产生的气溶胶沿代表性气道的时空沉积行为。原位测量的LIF信号与自发呼吸过程中沉积的气溶胶量有关。通过对LIF图像的后处理，在前8个分支中，LIF信号的时间过程与主要的气溶胶沉积机制，即惯性撞击和重力沉降，在导电气道中相关。根据呼吸周期的时间点，这两种沉积机制中的任何一种都主导着当前的气溶胶沉积。对八个后续分岔的空间分析表明，惯性沉积机制对更深分岔的影响逐渐减弱。此外，重力沉降的持续时间在分叉上减少，这取决于每个分叉的气道直径。引入无因次弗劳德数可以将测量到的气溶胶沉降与现有研究进行比较，并证明弗劳德5文献中提出的阈值限制与透明气道中观测到的重力沉降情况很好地匹配。对于弗鲁德>；5，在这个装置中，主要观察到惯性冲击作为气溶胶沉积的机制。对吸入空气相对湿度低对气溶胶蒸发和沉积的影响进行了误差分析。这一可行性研究表明，该测量方法与气道模型相结合，能够解决到第8分岔的气溶胶沉积。未来，该分析应通过显微LIF成像扩展到更高代的气道，以评估所有23代透明气道模型的沉积机制。

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引用次数: 0

Parabolic flow tube reactor for tandem DMA studies of cluster ion evaporation kinetics: Design, theoretical data inversion, and preliminary results for ionic liquid nanodrops 聚簇离子蒸发动力学的抛物流管反应器研究：设计、理论数据反演和离子液体纳米滴的初步结果

IF 3.9 3区环境科学与生态学 Q2 ENGINEERING, CHEMICAL

Journal of Aerosol Science

Pub Date : 2025-06-13 DOI: 10.1016/j.jaerosci.2025.106625

J. Fernandez de la Mora, C. Luebbert, L.J. Perez-Lorenzo

We seek to infer single-molecule evaporation rates from airborne ionic liquid clusters mobility-selected on a first DMA, flowing through a heated tube, with the ratio of product to parent fluxes determined on a second DMA. We connect theoretically the measured flux ratio to the reaction rate k via separation of variables, by assuming parabolic flow at large Peclet number (Pe). To minimize the non-parabolic entry flow region, we operate at moderate Reynolds numbers (∼150), resulting in a limited Pe. We identify practical conditions with small entry length and negligible finite-Pe corrections for the full (elliptic) non-reactive problem, which is numerically manageable despite the non-orthogonal eigenfunctions. We argue that moderate Pe corrections for the reactive problem are also small. The parent species problem is analogous to the nonreactive Graetz problem, though including the dimensionless first order reaction rate K as a free parameter. The product species problem involves an extra diffusivity ratio γ and non-standard functions, efficiently calculated by the computer program Mathematica. All other calculations involve diagonal matrices, enabling covering all the relevant range of dimensionless parameters: 1≤K ≤ 100; 1≤γ ≤ 1.4; arbitrary tube length x. These numerical results are condensed into tables for interpolations, enabling the quick inference of reaction constants from experimental data. The procedure is used to invert experimental data yielding the volatility of clusters of the ionic liquid EMI-FAP having diameters smaller than 3 nm. The approach is limited to situations where only one or two reaction products form.

我们试图从空气中离子液体团簇的迁移率推断出单分子蒸发速率——在第一个DMA上选择，流经加热管，在第二个DMA上确定产品与母体通量的比例。我们通过分离变量，假设大佩莱特数（Pe）的抛物流，从理论上将测量的通量比与反应速率k联系起来。为了最小化非抛物线入口流区，我们在中等雷诺数（~ 150）下操作，导致有限的Pe。我们确定了具有小入口长度和可忽略的有限pe修正的全（椭圆）非反应问题的实际条件，尽管具有非正交特征函数，但在数值上是可管理的。我们认为反应性问题的中等Pe修正也很小。母种问题类似于无反应的Graetz问题，但包含了无量纲的一阶反应速率K作为自由参数。积种问题涉及一个额外的扩散比γ和非标准函数，由计算机程序Mathematica有效地计算。其他计算均采用对角矩阵，可覆盖所有相关的无量纲参数范围：1≤K≤100；1≤γ≤1.4；这些数值结果被浓缩到表格中，以便插值，从而可以从实验数据中快速推断出反应常数。该程序用于反演实验数据，得到直径小于3nm的离子液体EMI-FAP簇的挥发性。这种方法仅限于只有一种或两种反应产物形成的情况。

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