XIA Liyuan, SUN Weiwei, CUI Miao, WU Yi

2020 (12): 1-8

doi: 10.16135/j.issn1002-0861.2020.0215

Abstract: To further study the genetic information and to promote the research on identification, phylogeny and population genetics of Lasioderma serricorne, the next-generation sequencing was used to acquire the complete mitochondrial genome of L. serricorne. The results showed that the mitochondrial genome of L. serricorne was 15 009 bp in length, which contained 13 protein-coding genes, 2 ribosomal RNA genes, 22 translocation RNA genes and a control region. The structure and organization of the genome were similar with those of the stored-product pests from Coleoptera. The A+T content of the whole mitochondrial genome was 78.7%. Except for cox2 whose start codon was TTG, the start codons of protein-coding genes were typical ATN codon. The stop codons of cox3, nad5, nad4 were incomplete T, and the other genes used the typical TAA or TAG as the stop codons. The 22 tRNA of L. serricorne could fold into a clover structure, however tRNA^Asp, tRNA^Leu, tRNA^His and tRNA^ser(AGN) folded into atypical cloverleaf secondary structures with the absence of either TψC-arm or D-arm.[Detail]

HU Anfu, FAN Wu, XIA Qian, ZHANG Qidong, SHI Qingzhao, ZHOU Guojun, XU Jian, CAI Xinghua, ZONG Yongli, JIANG Jian, CHAI Guobi

2020 (12): 27-36

doi: 10.16135/j.issn1002-0861.2020.0203

Abstract: To investigate the key burnt-sweet, creamy and bean aroma components in mainstream cigarette smoke and their distribution characteristics as well as sensory contributions, and to guide the flavoring of tobacco products effectively, the tobacco and tobacco smoke components listed in The Chemical Components of Tobacco and Tobacco Smoke were systematically evaluated. The components with burnt-sweet, creamy and bean aroma characteristics were screened and identified, and their distribution characteristics in total particulate matter (TPM) of mainstream smoke from 9 cigarette brands were determined by GC/MS. The contributions of those components to the burnt-sweet, creamy and bean aroma notes in mainstream cigarette smoke were assessed based on their odor activity values (OAVs). The results showed that:1) There were 18 components with burnt-sweet aroma note, 15 with creamy aroma note and 5 with bean aroma note in mainstream cigarette smoke. 2) In the mainstream smoke of different types of cigarettes, the releases of hydroxyacetone, 2,3-butanedione, methyl cyclopentenolone and 4-hydroxy-2,5-dimethyl-3(2H)-furanone were higher than those of the other components. 3) The total releases of the above 38 components in mainstream smoke of blended type cigarettes were remarkably lower than those of Virginia type cigarettes. 4) The contribution of burnt-sweet aroma note to mainstream cigarette smoke was more significant than that of creamy and bean aroma notes. The key components with burnt-sweet aroma note were 4-hydroxy-2,5-dimethyl-3(2H)-furanone, 3,4-dimethyl-1,2-cyclopentadione, methyl cyclopentenolone and 3-ethyl-2-hydroxy-2-cyclopenten-1-one, those with creamy aroma note were 2,3-butanedione, ethyl vanillin and vanillin, and those with bean aroma note were 6-methylcoumarin and dihydrocoumarin.[Detail]

YU Saibo, TAN Chao, WANG Shitai, ZHAO Yu, WU Yizi, FAN Hongmei, LI Ke, TAN Haifeng, LIU Qi, CHEN Qian, JIN Yong

2020 (12): 59-66

doi: 10.16135/j.issn1002-0861.2019.0510

Abstract: To study the factors influencing the combustion cone falling propensity (CCFP) for slim cigarettes, lit slim cigarettes were assessed via an in-house developed CCFP instrument and associated test methods. Four factors (cigarette weight, combustion promoter content in cigarette paper, moisture and stem contents in cut tobacco) on the CCFP of slim cigarettes were investigated through single-factor experiments, and results were analyzed by partial least square method (PLS). The results showed that:1) The CCFP of slim cigarettes sharply increased with the decrease of cigarette weight, greatly increased with the increase of the combustion promoter content in cigarette paper. It also clearly increased with the reduction of the moisture content in cut tobacco and slightly increased with the increase of the stem content in cut tobacco. 2) The linear relationships between the four factors and the CCFP of slim cigarettes were significant. The effect of cigarette weight was the greatest, followed by the combustion promoter content in cigarette paper, the moisture content and the stem content in cut tobacco. 3) By applying the above knowledge, the CCFP of a commercial slim cigarette was significantly reduced via increasing the cigarette weight during manufacturing.[Detail]

CHEN Zhibin, NONG Yingxiong, LIANG Dong, SUN Chen, WEI Yi, ZHONG Zhengyan

2020 (12): 75-82

doi: 10.16135/j.issn1002-0861.2020.0295

Abstract: In order to meet the demands of automatic collection of cigarette retail data, a method for cigarette brand recognition was proposed on the basis of deep learning. Firstly, design a detection model to detect the position and posture of cigarette packet image, and adjust the packet to right its image. Secondly, develop a feature extraction model to extract the feature of the image. Finally, generate a Euclidean distance threshold to search the cigarette feature with the highest similarity via the threshold from the cigarette feature database, and the cigarette brand associated with that feature was taken as the cigarette brand to be identified. The proposed method was tested in some cigarette retail stores in Nanning City of Guangxi Province, the results showed that the accuracy of the method for cigarette brand recognition was 98.0%, which indicated that the proposed method could meet the demands of automatic collection of cigarette retail data and had good generalization performance.[Detail]

XU Yalong, JIN Jingjing, ZHAO Yanzhen, WEI Pan, XI Jiaqin, YANG Jun, CAO Peijian, ZHANG Jianfeng

2020 (11): 1-6

doi: 10.16135/j.issn1002-0861.2020.0211

Abstract: In order to decipher the whole genome of Lasioderma serricorne, a genome survey was performed by high-throughput sequencing technology of Illumina. The genome size of L. serricorne was predicted, and the features of genomic heterogeneity, repeats and GC content were analyzed. Furthermore, the preliminary genome assembly was conducted. The results showed that the genome size of L. serricorne was 242.25 Mb. The heterogeneity percentage, repeats and GC content were 0.77%, 42.95% and 44.61%, respectively. Additionally, 418 693 scaffolds with a total length of 211.10 Mb were obtained after assembling. The scaffold N50 was 1 864 bp. The genome survey provides an important theoretical basis for the subsequent whole genome sequencing of L. serricorne.[Detail]

ZHAO Junwei, ZHAO Ge, LI Xiang, HUA Chenfeng, SHANG Pingping, WANG Sheng, HU Guochang, ZHENG Saijing, XIE Fuwei

2020 (11): 30-35

doi: 10.16135/j.issn1002-0861.2020.0092

Abstract: To investigate the smoking behavior of cigarette smokers and disposable e-cigarette users, a self-matching method was adopted. A total of 66 volunteers who smoked cigarettes were recruited and randomly divided into two groups(GroupⅠ and GroupⅡ). The two groups of volunteers were switched to smoke two types of e-cigarettes with different nicotine concentrations (12 and 20 mg/mL), and their general smoking characteristics were collected via questionnaires. CReSS Pocket was used to record the smoking parameters for smokers and e-cigarette users. The contents of total nicotine metabolites and cotinine in volunteers' urine were analyzed by HPLC-MS/MS, and the test results were corrected by urine creatinine. The results showed that:1)The mean puffing volume of the two groups for cigarettes were(50.3±17.2)and(47.9±20.6)mL, puffing duration times were (1.8±0.7) and (1.7±0.7) s, puffing intervals were (14.1±9.5) and (14.9±11.7) s, respectively. The mean puffing volumes of the two groups for e-cigarettes were(57.6±23.1)and(51.1±23.1) mL, puffing duration times were(1.9±0.7)and(1.7±0.7)s, puffing intervals were(9.4±9.3)and(11.0±9.3)s, respectively. 2)The contents of total nicotine metabolites in the urine of the two smoker groups were(6 641.6±3 599.3) and(6 290.3±3 155.5) ng/mg creatinine, the cotinine contents were(1 047.0±625.4) and(758.9±603.5)ng/mg creatinine. The contents of total nicotine metabolites in the urine of two vaping groups were (5 723.1±3 197.8)and(4 381.6±3 271.3) ng/mg creatinine, and the cotinine contents were(918.0±688.5)and (701.4±670.6) ng/mg creatinine(P<0.05). When switched to e-cigarettes, the puffing volume was increased, puffing interval shortened, and puffing duration prolonged or unchanged. However, the contents of total nicotine metabolites in the smokers' urine decreased after switching to e-cigarettes based on this small-scale volunteer study.[Detail]

WANG Le, HAN Jingmei, ZHANG Mingjian, LEI Ping, ZHANG Ke, SHANG Shanzhai, TANG Jianguo, LI Zhiqiang, HUANG Feng, LI Bin

2020 (11): 69-75

doi: 10.16135/j.issn1002-0861.2020.0166

Abstract: To investigate the retention behaviors of filters in electrically heated tobacco products(EHTPs) to the key aerosol components(nicotine, glycerin and 1,2-propanediol)of EHTPs, the amount of the components retained by different filters and different filter segments(i.e., cavity cellulose acetate section, polylactic acid section and cellulose acetate section)were measured. The retention rates were studied through a linear model and an exponential model to characterize the combined filters of EHTPs. The results showed that:1)Both the linear model and the exponential model could predict the retention rates of the key components in aerosols by the filters of EHTPs. 2)The retention rate by the cavity cellulose acetate section was the lowest, that of the polylactic acid section was moderate and that of the cellulose acetate section was the highest. The relationship between these three sections approximately met 1:2:3. 3)The retention rates of glycerol and 1,2-propylene by the cavity cellulose acetate section were higher than that of nicotine, and the retention ability of polylactic acid section to glycerol was relatively higher. 4)The retention abilities of cellulose acetate section to the three key components were basically the same. This study provides a mechanistic basis for the structural design and quantitative optimization of filters for EHTPs.[Detail]

SHI Chunxin, ZHENG Xudong, WU Jiande, LI Zhiqiang, WANG Chengya, WANG Ru, MA Jun

2020 (11): 89-96

doi: 10.16135/j.issn1002-0861.2020.0051

Abstract: To narrow the temperature fluctuation of heating elements in domestic heated tobacco products and promote the sensory quality of those products, an alumina ceramic-based heating element with platinum-based resistance paste conductive track and metallic silver welding plate and pins was experimented, and its temperature field distribution characteristic was analyzed with COMSOL Multiphysics software. Based on the temperature control requirements for heating elements, a temperature control circuit was designed to obtain the temperature field modeling parameters. According to the basic physical parameters and control parameters of the heating element, the multi-physics finite element simulation software COMSOL Multiphysics was used to establish a three-dimensional model of the heating element under the action of thermo-electric coupling and to obtain the temperature variations of the heating element under different working conditions. The simulation results were verified on an in-house test platform. The comparison between the simulation data and the testing data showed that:at the highest temperature, the maximum error between the two was 4.8% in preheating mode; it was 7.1% in constant temperature mode. The simulated values well agreed with the test values and the errors were within an acceptable range, which verified the effectiveness of the model and the simulation method. This technology provides a theoretical basis for the development and quality promotion of heating elements.[Detail]

XIANG Ligang, WANG Hancheng, GUO Hua, LI Zhiyi, ZHENG Ping, CAI Liuti, YU Zhihe

2020 (10): 1-9

doi: 10.16135/j.issn1002-0861.2019.0482

Abstract: In order to clarify the affecting mechanism of root irrigation with 3-methylbenzothiazole-2-thione secreted by corn roots on the community structure of bacteria in the rhizospheric soil of tobacco plants infected by bacterial wilt, Illumina MiSeq high-throughput sequencing technology was used to analyze the community structure of bacteria in the rhizospheric soil of tobacco plants infected by bacterial wilt on the day of the root irrigation as well as the 2nd, 7th, 20th and 40th days after root irrigation through pot experiments. The results showed that:1) There was no obvious bacterial wilt symptom 40 days after root irrigation with 3-methylbenzothiazole-2-thione, while all tobacco plants withered and died 40 days after root irrigation with sterilized distilled water. 2) After root irrigation with 3-methylbenzothiazole-2-thione, Sobs index, Chao1 index and Shannon index of Alpha diversity indexes of bacteria in rhizospheric soil of tobacco plants increased. 3) The dominant phyla were Actinobacteria, Proteobacteria and Chloroflexi and the dominant genera were Pseudarthrobacter, Sphingomonas and Gemmatimonas in all the five stages after irrigation with 3-methylbenzothiazole-2-thione. 4) Root irrigation with 3-methylbenzothiazole-2-thione increased the relative abundances of Actinobacteria, Nocardioides and Streptomyces and decreased the relative abundances of Saccharacteria and Sphingomonas in the rhizospheric soil of tobacco plants. Therefore root irrigation with 3-methylbenzothiazole-2-thione can effectively control tobacco bacterial wilt, affect the community structure of bacteria in the rhizospheric soil of flue-cured tobacco, and increase the relative abundances of beneficial bacteria.[Detail]

LI Yawen, CUI Huapeng, WANG Xiaofei, SI Xiaoxi, FAN Meijuan, CHEN Li, CAI Junlan, LI Xiang, LIU Shaofeng, XIE Fuwei, XIE Jianping

2020 (10): 32-38,55

doi: 10.16135/j.issn1002-0861.2019.0529

Abstract: To investigate the influences of puffing parameters on the physical properties and deposition in human respiratory tract of electronic cigarette (e-cigarette) aerosols, e-cigarettes were smoked by simulating human smoking under six puffing regimes at different puff durations (2, 3, 4 s), puff volumes (35, 55, 75 mL) and puff intervals (30, 60 s). The results showed that:1) With the increase of puff duration, the particle number concentration and particle size of the aerosols raised significantly, which further increased the amount of aerosol deposition in human respiratory tract. 2) At a higher puff volume, the particle number concentration of the aerosols increased, while the particle size decreased; and the deposition fraction and deposition particle number concentration increased, while deposition particle mass concentration slightly decreased. 3) Puff interval slightly influenced the physical properties and deposition in human respiratory tract of e-cigarette aerosols.[Detail]

WANG Liang, YIN Donghong, LI Bin, LIU Bin, MAO Weijun, YUAN Xinke, XIE Guoyong, DENG Nan, WU Mingjian, TAN Xinliang

2020 (10): 81-87

doi: 10.16135/j.issn1002-0861.2019.0555

Abstract: To study the influence and the mechanism of cut tobacco width on the CO release in mainstream cigarette smoke, the burning cone temperature of lit cigarettes made from tobacco of different cut widths was measured by a thermocouple method. The temperature distribution of the burning cone during machine-smoking was obtained via fitting of experimental results, and the correlation between the temperature distribution and CO release was analyzed. The results showed that:1) Cut tobacco width affected the shape and temperature distribution of the burning cone significantly. The total cone volumes and the high temperature (>600℃) section of the cone increased, while the low temperature (200-400℃) volume section of the burning cone decreased with the increase of cut width. 2) CO release mainly concentrated in two temperature ranges, 360-480℃ and 540-730℃ respectively, while the CO release below 350℃ was very low in comparison. 3) Mainstream CO release increased with the rise of characteristic temperature T_0.5 of the burning cone. T_0.5 could be effectively decreased by adjusting cut tobacco width so as to reduce CO release. When the proportion of tobacco at 1.5 mm cut width was 20%, T_0.5 decreased by 31℃, CO release was reduced by more than 1 mg/cigarette, and the hazard index of cigarette decreased accordingly.[Detail]

XU Longquan, WANG Shu, DONG Hao, PENG Qianrong, ZHOU Mingzhu, ZHANG Long, LUO Guangjie, YU Yunliu, WU Xiaosong, LI Zhigang, LIU Yong

2020 (10): 96-102

doi: 10.16135/j.issn1002-0861.2020.0090

Abstract: In order to accurately inspect the cigarette capsules with bubble defects in release inspection and discriminate bubble defect from stains, white spots, and other minor surface defects, a high precision inspection method based on computer vision was proposed. Firstly, the capsule area was precisely extracted via the image segmentation in an HSV (Hue, Saturation, Value) color space; secondly, the LoG edge detection operator was improved to enhance bubble contour and suppress the contours of the other defects; finally, the extracted contours were coded according to the "double liquid ring" characteristics of the bubbles to accurately recognize the bubbles. The proposed method was tested with capsule samples of three different specifications and of different colors. The results showed that the average recognition rate of the proposed method for bubble defects was 98.9%, the average false positive rate was 0.21‰, and the deviation was ±0.03% comparing with manual inspection. The proposed method features a higher recognition rate for bubble defects, and provides a support for promoting the appearance quality inspection of cigarette capsules.[Detail]

ZHAI Niu, ZHENG Qingxia, LIU Pingping, XU Guoyun, ZHANG Hui, LI Jing, CHEN Qiansi, WU Mingzhu, ZHOU Huina

2020 (9): 1-5

doi: 10.16135/j.issn1002-0861.2020.0027

Abstract: Chalcone isomerase (CHI) is one of the key enzymes in flavonoid metabolism. In tobacco, two copies of CHI genes, NtCHI1 and NtCHI2, are identified, while little is known on the function of NtCHI2 compared to that of NtCHI1. To study the function of NtCHI2, its rutin content, CHI activity, and NtCHI2 expression level were analyzed for NtCHI2-OE strains and NtCHI2-RNAi strains. We also examined the CHI activity of recombinant NtCHI2 expressed in vitro. The results showed that NtCHI2 had a CHI activity. In the NtCHI2-OE strains, the NtCHI2 expression level was up-regulated by 5-75 folds, however no significant changes in CHI activity and rutin content were detected. In NtCHI2-RNAi strains, the NtCHI2 expression level was down-regulated to 70%, and correspondingly, CHI activity and rutin content decreased by 50% and 90% respectively. NtCHI2 was involved in the metabolic regulation of rutin, and the expression of NtCHI2 was positively correlated with the rutin content to some extent.[Detail]

CHENG Wanyan, WANG Hongjuan, CHEN Huan, FU Yaning, WANG An, LIU Yong, HOU Hongwei, HU Qingyuan

2020 (9): 25-32

doi: 10.16135/j.issn1002-0861.2020.0039

Abstract: To investigate the effects of nicotine on the expression of inflammation-related cytokines in the hippocampus of rats, a conditional place preference (CPP) device was used to establish the acquisition, extinction and reinstatement of nicotine CPP in rats at the nicotine doses of 0.2 and 0.6 mg/kg. A total of 23 inflammation-related cytokines were detected simultaneously in the hippocampus at different stages (acquisition, extinction and reinstatement) by the suspension chip technique. The one-way variance analysis was adopted to analyze the differential cytokine expressions in the hippocampus at different stages using a nicotine preference model. The results showed that:1) Nicotine promoted the expressions of interleukin (IL)-1α and IL-10 and inhibited the expressions of IL-6, IL-18, growth-related oncogene/keratinocyte chemoattractant (GRO/KC) and regulated upon activation normal T cell expressed and secreted factor (RANTES) at low and higher doses. 2) The GRO/KC level in rat hippocampus was susceptible to nicotine, which reduced GRO/KC expression, while the reduction effect was weakened during the acquisition-extinction stage and was restored to the level at the acquisition stage during the extinction-reinstatement stage, the evidence therefore suggested that GRO/KC might be involved in the potential anti-inflammatory mechanism of nicotine. 3) The variation trends of the other five cytokine levels were different or even contrary to GRO/KC. Further studies are needed to understand the inflammatory mechanism of nicotine through the rat and other animal inflammation models.[Detail]

GAO Hui, YANG Jingjin, WANG Hui, WANG Yuzhen, LI Siyuan, LIU Jihui, HUA Yikun, WANG Xianguo, GAO Zhanyong, LIU Jing

2020 (9): 62-68

doi: 10.16135/j.issn1002-0861.2019.0368

Abstract: In order to evaluate the suitability of chromatic aberration as a method to monitor tobacco leaf cutting, the B2F, C3F and X2F cured K326 tobacco leaves were selected as test samples. After removing the petiole, a tobacco leaf was longitudinally divided into 10 locations at equal length. The lightness value (L^*), redness value (a^*), yellowness value (b^*) at each location were determined by a colorimeter. Regression analysis was used to study the variations of chromatic aberration values at different locations of K326.Appropriate sectioning proportion and sensory quality of tobacco leaves from different stalk positions were analyzed by Fisher's optimal segmentation method and sensory evaluation respectively. The results showed that: 1) For the upper, middle, lower leaves of cured K326, from the base to the tip, the L^* value presented a decreasing parabolic trend, and the values of a^*, b^* and △E (total chromatic aberration) presented an increasing parabolic trend first and then a decreasing one. 2) On the basis of the standardized chromatic aberration matrix, the optimal sectioning proportions for cured K326 were determined by Fisher optimal segmentation method as:20%:50%:30% for B2F (base:middle:tip); 30%:50%:20% for C3F (base:middle:tip), and 10%:30%:40%:20% for X2F (base:near base:middle:tip), respectively. 3) The results of three-point test indicated that the overall sensory quality differed significantly at the different locations. It was suggested that the chromatic aberration combined with Fisher optimal segmentation could effectively separate the locations with greatest sensory quality difference of the same leaf.[Detail]

SUN Zhiwei, WANG Wei, DU Wen, WEN Jianhui, XIE Guoyong, WANG Zhiguo, DAI Hongliang

2020 (9): 85-93

doi: 10.16135/j.issn1002-0861.2019.0474

Abstract: In order to develop the heating elements for electrically heated tobacco products (eHTPs) efficiently, an electro-thermal simulation model for heating blade was established by using simulation software. The temperature distribution in two kinds of heating blades under different voltages was taken as the objects to verify the consistency between the simulation values and the experimental values. The results showed that:1) The simulation values agreed with the experimental values generally, and the trends of their axial and radial temperature distribution showed good consistency. 2) Both the simulation result and the experimental result indicated that the temperatures differed significantly in the blades, the axial temperature difference reached 250℃ and the radial temperature difference was about 50℃ under normal working conditions. It suggests that the electro-thermal simulation is suitable for studying the temperature distribution in the heating elements for eHTPs, and the study results provides a reference for the design and development of the heating elements.[Detail]

XU Guoyun, ZHAI Niu, XU Yalong, XIE Xiaodong, ZHANG Hui, ZHENG Qingxia, ZHANG Jianfeng, LIU Pingping, CHEN Qiansi, JIN Lifeng, ZHOU Huina

2020 (8): 1-6,23

doi: 10.16135/j.issn1002-0861.2020.0004

Abstract: To investigate the mechanism underlying early flowering in tobacco caused by chilling stress, NtDUF599, a candidate gene related to the phenomenon was screened by RNA-seq analysis. NtDUF599 encoded a protein containing 236 amino acids with unknown functions, and its expression was highly induced by chilling stress. A RNAi plasmid, pBWA (V) HS-NtDUF599-RNAi vector, was constructed and a total of 10 different transgenic lines were generated by Agrobacterium-mediated transformation. Seedlings of non-transgenic and transgenic plants were treated with chilling stress (12 ℃) for 10 days and kept grown until bud stage under normal growth condition. We found that the emergence of flower buds of NtDUF599-RNAi transgenic plants was approximately 10 days earlier than non-transgenic plants. Furthermore, leaf numbers of NtDUF599-RNAi transgenic plants were less than those of non-transgenic plants. Those results revealed for the first time that DUFs （Domain of unknown functions） were involved in the chilling-induced early flowering in tobacco.[Detail]

REN Zongcan, CHEN Li, SHI Tiancai, WANG Xiaoyu, CUI Huapeng, XIE Fuwei, LIU Huimin

2020 (8): 24-35

doi: 10.16135/j.issn1002-0861.2019.0489

Abstract: In order to qualitatively analyze tobacco aroma components accurately and rapidly, a gas chromatography-tandem mass spectrometry (GC-MS/MS) method was established based on the retention indices (RI) of 241 tobacco aroma components. The retention indices of 241 target components were determined first by using standard samples, which accurately differentiated isomers in those standard samples and to realize rapid adjustment of the acquisition time window of the multi-analyte GC-MS/MS analytical method. The results showed that: 1) Among the retention indices of 241 aroma components, the differences between experimental determined values and those from the NIST17 database were less than 10 for 212 of the components, and the retention indices of the other 25 components had not been recorded in NIST17 database. 2) Adding retention index successfully promoted the accuracy and reliability of qualitative analysis among isomers. 3) Retention indices of the targets were used to predict the retention times of the target compounds under different chromatographic conditions, the time deviations of 232 components were within 0.05 min, and that of the other 9 components were within 0.05-0.10 min. It proved that the retention index had good stability in complex tobacco matrix and could be used to accurately predict the acquisition time window in multi-analyte GC-MS/MS method rapidly.[Detail]

ZHENG Songjin, ZHANG Yujie, ZHONG Liang, DUAN Haitao, WANG Danli, NIU Lina, WANG Haitao, LIU Yubin, YANG Yi

2020 (8): 65-71

doi: 10.16135/j.issn1002-0861.2019.0236

Abstract: In order to accurately determine the moisture content in tobacco during processing, a rapid method based on the CPMG signals of low-field nuclear magnetic resonance （LF-NMR） was established. The results were compared with those determined by the conventional oven moisture method. The results showed that：1） With the LF-NMR method, CPMG sequences were better than FID sequences, and the optimized sample volume and scanning numbers were 7 g and 16 respectively. 2） The established LF-NMR method featured good precision and high accuracy with the variation coefficients of intra- and inter-day precision less than 2%. 3） The LF-NMR method was more stable and accurate than the oven method, in addition the test time （2 min） was much shorter than that （150 min） of the oven method. The established method is suitable for the rapid and accurate determination of moisture content in tobacco.[Detail]

XU Lan, FU Jinggang, CHEN Jing, YE Huimin, ZHANG Yuan, ZHANG Jianchao

2020 (8): 86-92

doi: 10.16135/j.issn1002-0861.2020.0034

Abstract: In order to apply internal glue-line periodically for combined filter rod maker, a glue application system was designed on the basis of high speed solenoid valve technology. With an electromagnetic gluing gun, the system precisely controlled the gluing position, the number, space and size of glue spots in filter rod via regulating glue pressure and gluing gun parameters with an electrical control system. Furthermore, the system could be rapidly adjusted to adapt to combine filter rods of different specifications. Taking a KDF2 filter rod maker as an object, the system was tested, the results showed that it ran stably at the production speed of 200 m/min; no glue spot or glue residue was found at the cavity portion of dual or triple filter rod; and no missing or excess glue spots in the gluing area of filter rod; and the position deviation of glue spots was controlled within 2 mm. This technology provides a support for the production and application of combined filter rods with diversified structure.[Detail]