Particle aspect ratio is an important geometric parameter; however, its role in pneumatic conveying remains insufficiently understood. This study employed the bonded particle model (BPM) to construct shredded tobacco particles with 11 different aspect ratios, and simulated the industrial-scale pneumatic conveying process using the coarse-grained Computational Fluid Dynamics-Discrete Element Method (CFD-CGDEM). Particle conveying behavior in straight pipes, horizontal elbows, and vertical elbows was analyzed. The degree of radial mixing was quantitatively characterized by the Lacey mixing index (M). Simulation results revealed that particle aspect ratio influenced conveying characteristics through particle–fluid interactions and flow-induced motion characteristics. In straight pipes, particles with high aspect ratio were more likely to accumulate near pipe walls due to gravity (M < 0.1). In elbows, these particles showed stronger radial migration driven by curvature-induced flow and secondary flow, but the mixing uniformity was still low. When gas velocity was 18–27 m/s, the average particle velocity decreased approximately linearly as the aspect ratio increased. Under stable conveying conditions (21–27 m/s), the average residence time increased correspondingly. At higher gas velocities, the influence of gas flow on particle transport behavior became more significant, and the above correlations gradually weakened. The simulation results were validated by industrial-scale experiments under three gas velocity conditions (21, 24, and 27 m/s), with relative deviations in average residence time all below 5%. This study clarifies how particle aspect ratio affects pneumatic conveying, and provides a basis for optimizing the conveying of flexible elongated particles.

This study addresses key challenges faced by industrial multi-stage winnowing systems in the agricultural processing field when separating flexible filamentous particles and rigid acicular particles. These challenges include complex system structures, strong nonlinearity of gas-solid flow, and difficulties in the synergistic regulation of operational parameters. To overcome the computational efficiency bottleneck of traditional simulation methods at the industrial scale, this study develops a coarse-grained CFD-DEM coupled calculation framework suitable for these two types of heterogeneous particles based on the Energy Minimization Multi-Scale Discrete Particle Method (EMMS-DPM). Results show that the proposed model can effectively quantify the impact of multi-scale particle behaviors on separation efficiency. It also reveals the mechanism that stem stick particles with a thickness of ≥2.0 mm are more likely to be separated due to gravitational sedimentation. Furthermore, by simulating and optimizing the air intake velocity of the primary winnowing, the comprehensive winnowing efficiency is improved by 14.17% within an acceptable error range (the relative error between simulated and experimental values is within 6.0%). This research provides reliable numerical method support and theoretical basis for the parameter optimization and performance upgrading of industrial-scale winnowing systems.

The uniformity of tobacco blend mixing is a critical factor influencing cigarette quality. However, due to the dynamic nature of the blending process and the complex characteristics of the materials involved, current detection methods primarily rely on manual sampling or offline analysis. These approaches suffer from poor real-time performance and lack representativeness. To address these limitations, this study explores methods for generating tobacco-leaf image data and proposes a real-time semantic segmentation technique for tobacco-leaf images based on U-Net. First, a small set of tobacco leaf images was acquired to establish a raw dataset of composite tobacco leaf images. Three generative adversarial networks—CycleGAN, WGAN, and DCGAN—were employed to generate tobacco leaf images from this dataset. Based on image quality, the optimal image generation network was selected. Experimental results showed that CycleGAN produced the highest-quality tobacco leaf images. Next, the Squeeze Excitation Attention (SE) mechanism was integrated into the VGG16 backbone network. This enhancement improved the network’s ability to extract features from various types of tobacco leaf images while suppressing interference from irrelevant pixels. The results demonstrated that, compared to mainstream models such as Segformer, DeepLabV3, PSPNet, and the unmodified U-Net, the proposed SE-UNet model achieved superior segmentation accuracy, excellent real-time performance, and overall optimal segmentation capabilities. Compared to Segformer, DeepLabV3, PSPNet, and the original model, the MIOU in the evaluation metrics improved by 17.46, 8.7, 13.39, and 2.77 percentage points, respectively. Finally, the pixel areas of different tobacco leaf types were extracted and calculated from the segmented images to determine the proportion of each leaf type within the images. This research offers a novel approach for practical tobacco production and quality inspection, while also providing a new pathway for real-time online detection of other agricultural products.

ABSTRACT Reconstituted sheets manufactured from tobacco processing residues are a typical valorization pathway for agricultural fibrous byproducts, with important value for waste recycling and reducing harmful smoke constituents. However, domestic products often suffer uneven fiber distribution and batch inconsistency compared to international products. This study analyzes the component–structure–performance relationships of six reconstituted tobacco sheet samples via multiscale characterization. The domestic sample X‐1 possesses the highest carbohydrate content, which may contribute to differences in sensory characteristics, while ZY‐02 exhibited a developed pore structure associated with enhanced mass transfer potential. RM‐01 has unbalanced K/Cl ratio leading to poor combustion; high‐nicotine RM‐01 and RS22‐101 induced sensory irritation. Microstructurally, ZY‐02 featured a hierarchical pore network that improves mass transfer and strength, whereas RS22‐101 exhibited a relatively compact pore structure associated with lower mass transfer capability. Mondi Shanghai showed greater moisture stability via strongly bound water dominance. Based on these structure–performance relationships, potential optimization strategies were proposed for improving structural stability, additive distribution, and material consistency. Overall, this work provides a structure–performance framework that can help guide quality upgrades for domestically produced reconstituted tobacco sheets.

α-Terpineol, an abundant oxygenated monoterpene compound, shows a varied range of beneficial bioactivities. This study focused on the efficient extraction and purification of α-terpineol from the biotransformation of limonene using Penicillium digitatum DSM 62840 mutant (PdTP1-overexpressed OE2 strain). The α-terpineol was primarily distributed in the supernatant, with minimal association with the biomass. And the optimal extraction was achieved using ethyl acetate as the extractant, which can directly obtain the highest recovery of α-terpineol without sequential extractions. The equilibrium of mass transfer was quickly reached (≤20 s in vortex). Additionally, the purification method of α-terpineol using column chromatography was described, further improving the purity of product to 96.86% in gas chromatography. Structural identification of purified α-terpineol was confirmed using gas chromatography-mass spectrometry, Fourier-transform infrared spectroscopy, and nuclear magnetic resonance. This simplified and efficient strategy for the extraction and purification of α-terpineol not only provides a solid theoretical basis for the final step in the relevant study of microbial synthesis of α-terpineol but also is of great significance for its industrial application.

As intelligent technologies rapidly advance, the tobacco industry faces both opportunities and challenges in enhancing production efficiency and product quality. Quality control is a crucial aspect of tobacco shredding, but traditional manual inspection methods are no longer adequate to meet the demands for efficiency and precision. To tackle this issue, this study proposes a tobacco quality prediction model based on the Random Forest Algorithm. The aim is to enhance the accuracy and reliability of quality assessment by analyzing key process parameters in the shredding process. The model was trained and evaluated using cross-validation, and experimental results demonstrate its high prediction accuracy (over 93%) and robust generalization capability. Additionally, feature importance analysis has revealed the contribution of each key process parameter to tobacco quality, offering scientific insights for optimizing production processes. This study provides new theoretical foundations and practical guidance for intelligent production and quality control in the tobacco industry.

The pneumatic conveying drying process is widely used due to the high mass- and heat-transfer efficiency between the gas and solid phases, large dehydration rate, and wide range of operation conditions. The flexible ribbon particles are often involved in the pneumatic conveying drying of agricultural products, food, and biological products. These types of particles are easy to hold together due to the flexibility and the nonuniformity of ribbon shape. It is important to understand the dynamic behaviors of flexible ribbon particles in a pneumatic conveying dryer. Therefore, research on flexible ribbon particles in a pneumatic conveying dryer is necessary. However, previous studies were scarcely concerned about the particle of this special type. The flexible ribbon particles in the gas-solid fluidized bed would exist in the form of single discrete particles or clusters. Moreover, the hydrodynamic characteristics were impacted by the inhomogeneity of particle flow, which affected the performance of the pneumatic conveying dryer. In this paper, the flexible ribbon chain model was proposed, and the 3D flexible ribbon particle computing method with GPU was established. The dynamic behavior of the flexible ribbon particles was investigated in a pneumatic conveying dryer. Specially, the effects of particle flow rate, superficial gas velocity, and other parameters on the dynamic behavior of flexible ribbon particles were analyzed. The experimental verification was also performed by a fluidization test of cut tobacco particles. The results provide guidance for the further study of ribbon particles.

Summary For tobacco strips used in cigarette production, the stem content is an important quality index to assess the impurity level of the cut leaves. The presented work developed a nondestructive detection method of stems in cut leaf agricultural products by the low energy X-ray imaging. The algorithm of stem image processing and weight calculation principle was established, and then a machine vision system with X-ray imaging and image analysis was set up to verify the quantitative detection method. The results showed that the relative error of the detection method ranged from −3.64% to 2.76%. The determination of stems with a different morphology, such as the thick stem, were also realized based on the image analysis. The accuracy of determining thick stem and long stem was 94.67% and 99.33%, respectively. The developed method is superior to the current ISO detection method of tobacco stem in leaves under the same testing conditions in terms of accuracy and efficiency, which could be applied as an effective online detection method to monitor the quality of processed leaf for cigarette production.

为提高烟丝结构检测及烟丝组分分析的准确性,基于图像识别技术,对烟丝轮廓进行细化,提取烟丝骨骼,得到烟丝长度,建立烟丝表观总面积与质量的拟合模型,获得烟丝结构(整丝率、碎丝率);利用最小内切圆的方法得到烟丝的平均宽度、宽度方差,烟丝轮廓在饱和度(Saturation,S)通道上的颜色方差,以及HSV颜色模型的颜色矩,用支持向量机(Support Vector Machine,SVM)作为分类器,构建薄片丝、梗丝、叶丝的烟丝组分分类模型.实际应用结果表明:基于图像识别的方法能准确统计整丝率、碎丝率,且比传统振筛法更快捷、有效,与卷积神经网络法和残差神经网络法相比,该方法识别薄片丝、梗丝、叶丝的平均相对误差≤5％,准确性及可行性更高.

为快速测定烟叶新植二烯含量,构建了5 m DB-5ms预分离柱结合10 m DB-5ms分析柱的反吹柱系统,确立了反吹压力103 kPa,反吹时间4.5 min的色谱条件及采用10 mL二氯甲烷涡旋提取0.5 g烟粉5 min的前处理方法,并对114个国内外代表性烟样进行了分析.结果表明:①新植二烯在10～200μg/mL范围内线性良好(相关系数r?0.9999).新植二烯定量限为16μg/g,加标回收率在98％～101％之间,日间、日内相对标准偏差分别为1.81％和1.76％,长期(两年)相对标准偏差小于5％.每个样品分析时间仅为8 min.②将国内5个生态区烟叶与代表性进口烟叶中新植二烯含量进行对比分析,西南高原生态区烟叶与代表性进口烟叶无显著性差异;其余4个生态区(武陵秦巴、南岭丘陵、武夷丘陵、沂蒙丘陵)烟叶与代表性进口烟叶有显著性差异.③无论从整体还是从每个生态区分析烟叶新植二烯含量,上部烟叶与中部烟叶无显著性差异,与下部烟叶相比,均有显著性差异,下部烟叶新植二烯含量较高.本研究通过反吹气相色谱-火焰离子化检测器检测烟叶新植二烯含量,所建方法简单、快速、灵敏度高、重复性好,可用于不同产区、不同部位烟叶中新植二烯含量的批量定量检测.

Smokeless tobacco products provide an alternative to cigarettes; however, smokeless tobacco is carcinogenic and harmful to human health. This study evaluated the toxicological effects of snus extracts and cigarette smoke total particulate matter (TPM) on human umbilical vein endothelial cells (HUVECs). Treated cells were examined for cell viability, reactive oxygen species (ROS), apoptosis, and inflammatory cytokines. Moreover, we explored the mechanism of programmed cell death induced by snus. The results showed that snus extracts significantly inhibited cell viability in a dose-dependent manner. ROS was significantly increased in treatment groups, and anti-oxidant treatment could not prevent snus extract-induced cell death. Snus extracts induced apoptosis, DNA damage, activation and cleavage of caspase-3 and caspase-8, pathway-related gene change, and interleukin (IL)-6 and IL-8 release in HUVECs. Snus extracts exposure may induce cytotoxicity, ROS generation, inflammatory cytokines release, and apoptosis or DNA damage through intrinsic and extrinsic pathways in HUVECs.

为提升烟梗利用率及梗丝加工质量,研究了微波膨胀烟梗制丝加工过程中烟梗分选、蒸汽微波协同膨胀、膨胀烟梗回潮、烟梗复切、气流干燥等关键工序中工艺参数对梗丝加工质量的影响,得到优选的工艺参数为:1)烟梗分选工序中选择长度≥2 cm的短梗和直径≥3.0 mm的细梗;2)蒸汽微波协同膨胀工序中物料流量240～270 kg/h,过热蒸汽流量950～1050 kg/h,腔体温度148～151℃,微波功率36～39 kW;3)膨胀烟梗回潮工序中水洗时间>50 s,回潮后含水率在30.5％左右,回潮后贮存时间≥4 h;4)烟梗复切工序中采用前高后低的组合方式,切片厚度0.60 mm,切丝宽度0.30 mm,刀门压力30～35 kN,刀辊转速400～450 r/min;5)梗丝气流干燥工序中物料流量150 kg/h,工艺气体流量6500 m3/h,温度196℃.在该制丝工艺条件下加工的梗丝宽度与叶丝更接近,梗丝结构更加均匀,梗丝综合质量较好.

In this work, the thermal degradation behaviors of two kinds of biomasses (pinewood and rice husk) with powder and pellet under three oxygen concentrations were investigated by a self-designed macro-thermo-gravimetric analyzer. An obvious hysteresis of thermal degradation of biomass pellets was observed under three conditions. The maximum activation energy of biomass pellets was significantly greater than that of biomass powders, while their average activation energies were almost equal based on distributed activation energy model. For the oxygen-rich combustion, the comprehensive combustion character index of powdered and pelletized biomasses ranged from 3.92 x 10(-7) to 5.16 x 10(-7)%(2).min(-2.)degrees C-3 and from 1.82 x 10(-7) to 1.91 x 10(-7)%(2).min(-2.)degrees C-3, respectively. Furthermore, the derived biochar of powdered biomass has a higher caloricity than that of pelletized biomass during combustion by TG-DSC analysis. The performances of thermal degradation observed by macro-thermogravimetric analyzer could factually reveal the influence of mass and heat transfer on the thermochemical conversion of powdered and pelletized biomasses.

针对现有卷烟感官品质评价方式的评价结果差异不明显和变化趋势不明确的问题,建立了一种新的烟草感官品质对比评价方法:采用专家咨询法并结合实际评吸经验,根据消费者的关注程度对优雅度、满足感、舒适感和轻松感各感官品质评价指标赋予权重,利用数理统计方法对各评吸人员的评价结果进行计算,得出卷烟各感官品质评价指标小项和总体得分,并根据各项得分判定实验样品间感官品质差异程度和变化方向.可行性验证结果表明:该方法即使在感官品质变化较小时,也能够较好地从分值上进行区分;其既能反映整体感官品质的差异程度,又能反映总体或单个感官品质评价指标的变化趋势,且感官品质差异性的区分度也较明显,可应用于卷烟制品的研发和品质控制.

Curing is an essential procedure in tobacco primary processing. The moisture mobility and diffusion characteristics during drying are the key factors that affect the curing condition optimization. In the present study, the thermogravimetric analysis (TG) was integrated to the online nuclear magnetic resonance analysis (NMR) to investigate the drying characteristics of fresh tobacco leaves (FTL) during hot air drying at 50 and 60 °C. The results of TG were used to analyze the drying kinetics and obtain the effective diffusion coefficient of moisture of FTL during drying. The moisture diffusion coefficient of FTL was 4.1782E−09 m 2 s −1 at 50 °C and 5.7777E−09 m 2 s −1 at 60 °C, respectively. The moisture mobility of the samples at different drying stages was monitored by the NMR analyzer. T 2 spectra showed that the initial ratios of semi-bound water and bound water in FTL were 93.2 and 6.8%, respectively. The drying rate showed a decreasing trend with the reduction in relaxation time of T 22 peak from about 80 ms to about 30 ms, especially for the ones dried at 60 °C. The reduced relaxation time of T 22 peak indicated that water activity in FTL was weakened during drying. Moisture distribution obtained by magnetic resonance imaging in FTL at different drying stages can reveal the moisture transfer path.

采用3因素5水平的正交实验方法研究了不同酶解时间、酶解温度和漆酶用量对梗丝中木质素降解率的影响,同时对漆酶处理前后梗丝的化学成分和填充值进行测量,结果表明:不同酶解时间、酶解温度和漆酶用量极显著影响着木质素的降解率.使用漆酶降解梗丝中木质素的最佳参数是:酶解时间4h,酶解温度50℃,漆酶用量10.0 μL/g.在该参数条件下,梗丝中的木质素降解效果最好,降解率高达47.3％.使用漆酶处理梗丝后,除了木质素之外,梗丝的其它化学成分含量基本不发生变化,填充值也基本没有影响.在最优的参数条件下,使用漆酶能在不降低梗丝原有品质的前提下有效的降解梗丝中的木质素,提高梗丝的品质和可用性.

The particle size was an important factor that can affect the thermal degradation behavior of biomass during thermochemical conversion. In this work, the thermal degradation behavior of flue-cured tobacco with different particle sizes for thermochemical conversion was investigated by a self-designed macro-thermogravimetric analyzer (macro-TGA) under inert and oxidative conditions. During pyrolysis and combustion, the thermal degradation behavior could be described by a four-stage and five-stage mass loss reaction, respectively. At the second mass loss stage, for six cut tobaccos, the mass loss rate increased with the decrease in particle size during pyrolysis and combustion. In addition, the combustion character index of cut tobaccos ranging from 3.0480 × 10−7 to 4.4825 × 10−7%2 min−2 °C−3 also increased with the decrease in particle size. Furthermore, the mass change data recorded by the macro-TGA were used to estimate the kinetic parameters, such as the apparent activation energy and the pre-exponential factor, based on distributed activation energy model. For the thermochemical conversion of tobacco materials, it was found that the apparent activation energy increased with the increase in conversion rate for pyrolysis reaction under inert condition, while the apparent activation energy reached a maximum within a certain conversion rate in the middle of combustion reaction under oxidative condition. As well, the kinetic compensation effect was evaluated by the equation $$\ln A = \varphi \times E + \psi$$. The investigation on thermal degradation and apparent kinetics of tobacco revealed the effect of particle size on thermochemical conversion, which can provide a reference for building a more accurate cigarette combustion model.

为对梗丝形态差异性进行评价,通过测量单一形态梗丝周长、面积并采用“小岛法”计算其分形维数及形态指数,以叶丝形态为标准,选取梗丝与叶丝分形维数及形态指数的差异为指标,建立梗丝形态差异性系数模型及评价方法并验证分析.结果 表明:①单一形态梗丝拟合方程决定性系数R2均达到0.850,且均方差及残差均较小,表明“小岛法”可准确计算其分形维数.②梗丝形态具有分形特性且不同形态梗丝分形维数具有明显差异,随着分形维数逐渐增大梗丝形态越来越不规则.③所建梗丝形态差异性系数模型Ye=4.825XDi-D'-1.149X(K)-(K)'+0.320,决定性系数R2达到0.948,F检验达到显著水平表明回归模型具有统计学意义,且模型经验证准确可靠.④初步建立了一种梗丝形态差异性评价方法,以差异性系数e为指标,梗丝形态间差异性小(P≤0.491);较小(0.491 ＜e≤0.813);适中(0.813＜e≤1.189);较大(1.189＜e≤1.565);大(e＞1.565),该方法可通过定量指标实现对梗丝形态差异性的定性分析.

To accurately determine the amount of seam glue in cigarette tobacco rod, a method was developed by using zinc chloride as a marker. The glue containing zinc chloride was applied on the rod seam which was manufactured using routine technical parameters. The cut tobacco in tested cigarettes was removed, and the content of zinc chloride in the remaining cigarette paper tube was determined by ICP-MS after microwave digestion. The results showed that: 1) The detection limit of the method was 0.021 μ g/L, the relative standard deviations (RSDs) and recoveries were in the range of 0.85%-1.35% and 97.8%-103.4%, respectively. 2) The RSD of determined glue amount was less than 2.0% at the zinc ion addition rate of 2.5-6.0 mg/g. 3) The determined amount of seam glue agreed reasonably well with the design value of the glue amount by the online control system. The method is suitable for accurately determining the amount of seam glue in cigarette tobacco rod.