闭环回路气提法的烟叶香气成分特征判别研究

为了比较不同产地不同香型烟叶风格特征的差异,应用闭环回路气提法(Closed-Loop Stripping Analysis,CLSA)对我国5大烟叶产区(黄淮、东南、西南、长江中上游、北方)3种不同香型122个C3F等级烟叶进行挥发、半挥发成分指纹图谱研究;结合组分对香型的贡献性、烟叶中的含量及试验结果的重复性,选取20种挥发、半挥发性成分作为检测对象,采用判别分析方法(Discriminant Analysis,DA)对其含量差异进行了比较分析。结果表明:挥发、半挥发成分与香型及产地关系明显,同香型不同产地差异很大,①浓香型烟叶整体挥发、半挥发成分含量较高,香味物质含量较突出,但是新植二烯含量在3种香型中最低,东南、黄淮两大产区差异较大。②中间香型挥发、半挥发成分没有较为突出的个性特征,整体上,北方产区与其他产区差异明显。③清香型烟叶中的新植二烯含量为3种香型中最高,是清香特色的主要因素之一,福建地区与云南、四川等地差异较大:     

不同钾肥对烤烟叶片钾和中性香气成分及非挥发性有机酸含量的影响研究

采用盆栽试验研究了不同种类钾肥对烤后烟叶的钾和中性香气成分及非挥发性有机酸含量的影响,以及钾含量与中性香气成分及非挥发性有机酸含量的关系.结果表明,施用钾肥提高了烤后烟叶的钾含量和中性香气成分及非挥发性有机酸总量,降低了亚麻酸、亚油酸和柠檬酸的含量.钾含量和中性致香物质总量以K2SO4增施生物钾肥处理最高,非挥发性有机酸总量以单施KNO3处理最高,钾含量和中性香气成分及非挥发性有机酸含量均以单施生物钾肥处理最低.烤后烟叶钾含量与中性香气成分含量呈显著正相关,与非挥发性有机酸含量呈极显著正相关,说明提高烤后烟叶钾含量能够提高烟叶的中性香气成分及非挥发性有机酸含量.     

基于电子鼻技术的烤烟过程气味变化研究

为了掌握烟叶烘烤过程中气味变化的规律,用金属氧化物半导体传感器阵列组成的电子鼻对烤烟烟气进行实时监测。详细阐述了自制的电子鼻系统和实验过程,在对样本数据进行预处理后,采用主成分分析法对样本进行分析。分析结果表明:利用电子鼻技术得出的气味综合曲线能够真实有效地反映烟叶烘烤过程中的气味整体变化趋势,并且分析得出的烤烟过程中气味变化规律与现有烟叶烘烤理论较好地吻合。     

皖南烟叶香气成分因子及关联度分析

为探讨各类香气物质对皖南地区烟叶特殊香型形成的作用,本试验对皖南地区四种典型土壤所产烟叶香气进行了因子分析,及香气综合评定值与土壤养分的关联度分析。结果表明:利用因子模型在阐明以因子形式表现的香气物质变量间的关联时,可信度高。因子分析证明类胡萝卜素类物质降解产生的香气物对烤烟香气影响最显著,可推断烤烟的香气特色主要是由烟叶中类胡萝卜素类降解产物的量及协调程度决定的,这其中又以巨豆三烯酮最为重要。在皖南地区烟株生长及香气品质形成过程中,土壤pH值起重要作用,土壤速效钾、全磷影响作用逐渐增加,碱解氮、有机质影响作用逐渐降低。     

基于Tabu搜索的贝叶斯网络在烟叶香型评价中的应用

烟叶香型通常是靠人的嗅觉评定的,评定结果的准确性往往难以保证。针对该问题,国内外建立了BP神经网络等感官评估模型,但识别效率不高。根据烟叶中化学成分与烟叶香型关系,使用基于Tabu搜索的贝叶斯网络建立烟叶香型识别模型。实验结果表明,使用该方法能得到较好的贝叶斯网络结构,与BP神经网络等方法相比训练效率更高,分类的结果也更加准确。     

烟叶香气风格分类中的特征选择算法研究

烟叶香气风格分类是利用烟叶外观质量、理化成分判定其香型、香气质量的类别.为了提高分类能力,通过特征选择发现最佳属性集是一种有效的方法.本文对比研究了信息增益率(GainRatio)、ReliefF、CFS、Wrapper四种特征选择方法改善烟叶香气分类器性能的差异.实验结果表明:基于遗传算法的Wrapper方法优于其他三种方法,所得最佳属性集的特征维数低,而且使分类精确率大大提高.     

基于主成分分析的烟草质量一致性评价

研究了以烟叶化学成分为基础,利用主成分分析和聚类分析方法对烟草质量一致性进行评价的方法。该方法采用主成分分析方法,剔除了原始指标之间的重复信息,将原有的17种常规化学成分指标变量综合为3个主元成分变量代替。依照烟草样本主成分特征数据,以类内离散度为衡量指标评价同一批次烟草质量的一致性。用此方法对5个批次、不同类型的烟草进行了一致性评价,评价结果表明,成品烟丝的一致性最好,原料烟叶的一致性相对较差,该结果与传统评价结果一致。本文提出的评价方法基础数据易得,实现简单,评价结果贴合实际。     

低引燃卷烟感官变化的感官分析新方法

为更直观、更清晰的反映评吸员对于卷烟感官质量变化的真实感受,基于传统的感官评价经验设计一种新的卷烟感官分析方法,以利于更好的研究低引燃倾向卷烟(Low Ignition Propensity,简称LIP卷烟)的感官质量变化。采用一种卷烟感官评价词频分析新方法对感官描述性文字进行分析,结果表明:1同一牌号烤烟型LIP卷烟与其正常卷烟相比较感官差异明显,主要变化为刺激增大,余味欠舒适,谐调略降,杂气明显,香气量减少,烟气浓度降低,风格有差异;2同一牌号混合型LIP卷烟与其正常卷烟相比较感官也有差异,但是变化比烤烟型卷烟小;3与传统的国标方法比较,新方法展示更直观,能较客观揭示LIP卷烟感官质量的具体变化;4新方法具有较好的应用前景,可以应用于烟叶原料和其他卷烟感官分析。     

基于KICA-KFDA的集成故障识别算法

针对复杂的化工过程,提高过程监控能力,提出基于核独立成分分析（kernel independent component analysis,KICA）和核Fisher判别分析（kernel fisher discriminant analysis,KFDA）的过程监测与故障识别方法。通过利用核独立成分分析建立正常工况模型,得到检测故障信息。在发生故障的情况下,利用Fisher判别分析方法在高维的特征空间的特点和优势,可求出满足最大分离程度的核Fisher判别向量和特征向量,根据当前故障的判别向量和历史故障数据集中所含故障的最优核Fisher判别向量的相似度进行故障识别。仿真结果验证了所提方法的有效性。     

一种基于计算机嗅觉的卷烟等级识别方法

为利用计算机嗅觉系统(电子鼻)快速、简便地识别同种品牌不同等级的卷烟,选取三种不同等级的“双喜”牌卷烟作为实验对象,利用PEN3电子鼻分别检测整盒(未开封)、滤嘴、烟丝、烟纸、烟气等5个方面的气味,并利用主成分分析(PCA)和主成分分析+线性判别分析(PCA+LDA)分别对该5种气味信息进行分析.最后利用相关性分析对整盒气味信息的待测样本进行了区分测试.结果显示:单独利用5种气味的信息都区分出三种等级,其中区分效果由优到劣依次是滤嘴、烟气、整盒、烟丝、烟纸.利用相关性分析方法对整盒待测样品的测试正确率达100％.     

湖南产鱼腥草挥发油GC/MS数据的分析

本文利用化学计量学分辨方法和基于局部平滑的化合物确认方法解析了湖南怀化产的鱼腥草挥发油的GC／MS数据，鉴定了其中55个组分，为建立鱼腥草注射液的质量标准奠定了基础。     

Experiencing Nature: Embodying Animals in Immersive Virtual Environments Increases Inclusion of Nature in Self and Involvement With Nature

Immersive virtual environments (IVEs) produce simulations that mimic unmediated sensory experiences. 3 experiments (N = 228) tested how different modalities increase environmental involvement by allowing users to inhabit the body of animals in IVEs or watch the experience on video. Embodying sensory‐rich experiences of animals in IVEs led to greater feeling of embodiment, perception of being present in the virtual world, and interconnection between the self and nature compared to video. Heightened interconnection with nature elicited greater perceptions of imminence of the environmental risk and involvement with nature, which persisted for 1 week. Although the effect sizes were small to moderate, findings suggest that embodied experiences in IVEs may be an effective tool to promote involvement with environmental issues.     

基于GC-MS数据的定性分析新方法

利用二维气相色谱质谱数据，根据随机噪声和信号在质量色谱峰的不同性质，本文提出了基于局部平滑的化合物确认方法。除去色谱峰中的随机噪声后，可较为准确地得到该色谱峰所对应物质的分子离子或准分子离子的信息。由于强调了利用质谱分子离子或准分子离子的信息，本方法可显著地提高质谱定性分析的准确度。     

A mass spectrometric strategy for profiling glycoproteinoses, Pompe disease, and sialic acid storage diseases

Glycoproteinoses, Pompe disease, and sialic acid storage diseases are characterized by a massive accumulation of unprocessed oligosaccharides and/or glycoconjugates in urine. The identification of these glycocompounds is essential for a proper diagnosis. In this study, we investigated the potential of MALDI‐TOF‐MS to identify glycocompounds present in urine from patients with different inborn errors of glycan metabolism. Urinary glycocompounds were permethylated, and analyzed using GC‐MS and MALDI‐TOF‐MS. In order to confirm tentative assignments, a second aliquot of urine was purified on a C18 Sep‐Pak cartridge and glycocompounds were desalted on a column of nonporous graphitized carbon. The glycocompounds were then sequentially on‐plate digested using an array of exoglycosidases. A range of disease‐specific oligosaccharides as well as glycopeptides was identified for all oligosacchariduria models. In addition, free sialic acid accumulated in urine from a patient suffering from French‐type sialuria, has been detected by a GC‐MS approach, which could be applied to other sialic acid storage diseases. This procedure is simple, and can be performed in few simple steps in less than 24 h. This current method can be applied for newborn screening for other inherited metabolic diseases as well as for assessing treatments in clinical trials.     

Towards defining the whole salivary peptidome

We report the identification of 2294 peptides/proteins in whole saliva in the mass range between 700 and 16 000 Da by LC‐MS and MS/MS using a MALDI‐TOF/TOF mass spectrometer. Most of the identified peptides/proteins are originated from cellular debris or plasma components while only 26% (n = 607) correspond to salivary peptides/proteins species. In spite of the presence of the major salivary peptides in all samples from the six subjects analyzed, each individual presents a different pattern of fragments, many deriving from the same protein sequence. All our data, in particular the large number of fragments found, suggest high proteolytic activity insight the oral cavity. The analysis of samples by gelatin zymography showed that all saliva donors displayed multiple proteolytic bands, two identified as cathepsin D and G by MS. Analysis of the cleavage site distribution on the main peptide sequences based on contingency tables shows that the predominant cleavages occur between Gln‐Gly or Tyr‐Gly. These cleavages are largely associated with proline‐rich proteins peptides and with histatin 1 and P‐B peptide, respectively. However, depending on the peptide class, different cleavage hits were observed suggesting the presence of a set of proteases acting in different ways according to different peptide sequences. Comparing the number of cleavages involving all residues, it is possible to observe that 44% (±10%) of the observed cleavages in histatin, statherin and P‐B peptide in all individuals may be explained by cathepsin D, suggesting a major role for this enzyme in oral cavity proteolysis.     

卷烟主流烟气粒相物硅烷衍生化GC-MS数据的解析

应用化学计量学方法对卷烟的主流烟气粒相物中极性非挥发物硅烷衍生化的CC-MS数据进行了解析。首先应用主成分分析法判断各色谱峰中的化学成分数。对于其中含有多种成分的重叠峰,应用多变量曲线分辨-变换最小二乘法(MCR- ALS)进行解析。用最大不相关法选取MCR-ALS的一组初始迭代矢量。最后根据总离子流图对解析得到的色谱峰曲线进行标度化。对选定样品的GC-MS数据进行判别,发现17％的色谱峰是2种或3种成分的重叠峰,经过解析可得到较好的色谱图和质谱图。结果表明了此方法在复杂样品的GC-MS数据解析中的有效性。     

南果梨果心挥发性成分的分析

用同时蒸馏萃取装置(SDE)提取南果梨果心挥发性成分，测得南果梨果心中挥发性成分的含量为0．25％，用GC／MS法从南果梨果心挥发性成分中分离并确认出50种化学成分，用峰面积归一法通过G1710BA化学站数据处理系统得出各化学成分在挥发性成分中的百分含量，其中主要成分为依兰烯(29．78％)，2，6一二甲基-6-(4-甲基-3-丙烯基)双环[3．1．1]庚-2-烯(9．53％)，1-甲基-4-(5-甲基-1-甲烯基-4-己基)环己烯(6．43％)等，占总检出量的80．66％。     

逐步校正迭代算法及其在两组分包埋色谱峰解析中的应用

在残差双线性分解算法的基础上,提出了一种新的用于解析两组分包埋色谱体系的方法,即逐步校正式迭代算法.此算法基于以下2个基本假设:(1)必须存在相应于大色谱峰对应组分的选择性区域;(2)二维数据矩阵必须满足双线性.基于选择性离子,本文同时提出了一种的简单易行的对解析结果的可靠性进行验证的方法.将此法用于2个模拟分析体系和2个气质联用数据的解析,得到了令人满意的结果.     

An improved generalized Hough transform for the recognition of overlapping objects

The generalized Hough transform (GHT) is a powerful method for recognizing arbitrary shapes as long as the correct match accounts for both much of the model and much of the sensory object. For moderate levels of occlusion, however, the GHT can hypothesize many false solutions. In this paper, we present an improved two-stage GHT procedure for the recognition of overlapping objects. Each boundary point in the image is described by three features including the concavity, radius and normal direction of the curve segment in the neighborhood of the point. The first stage of the voting process determines the rotational angle of the sensory object with respect to the model by matching those points that have the same concavity and radii. The second stage then determines the centroid of the sensory object by matching those points that have the same concavity, radii and rotational angles. The three point features remove the false contribution of votes in the vote generation phase. Experimental results have shown that the proposed algorithm works well for complex objects under severely overlapping conditions.     

熟地黄石油醚酸性提取物的解析与鉴定

对熟地黄石油醚提取物中酸性部分分离后进行甲酯化，用气相色谱－质谱联用仪测定甲酯化产物，供助直观推导式演进特征投影（HELP）法进行快速分辨以得到各个组份的纯色谱和质谱，利用质谱库检索，并结合色谱保留指数对各个组份进行定性。