热分析方法及裂解气相色谱在树木分类上的试探性研究

热分析是在程序控制温度下自动连续跟踪物质的物理性质与温度关系的一类技术。尤其是差热分析和热重法与其他手段联合,可用于化合物稳定性、分解机理和相转变等方面的研究。由于种子是一个复杂化合物的有机体,我们期望发现各不同种子化合物之间在成份上和组成方式上的共性和差异性,从热化学的角度对木本植物进行热化学分类。我们选用针叶类两个科（松科、杉木科）的种子进行了ＤＴＡ、ＴＧ、５５０℃裂解气相色谱分析;３００℃逸出成份分析,发现松科种子ＤＴＡ图上在２４０±５℃有一个共同的吸热峰,而杉木则出现在３２０±５℃。ＴＧ曲线同科的不同种之间非常相似,逸出成份分析和裂解气相色谱分析同科的不同种之间也具共同特征,且又显示出一定的差异性。这种分类方法是可靠的,且可为树木（或植物）分类学提供更有价值的信息。     

羊蹄甲属植物种子的裂解色谱鉴定法研究

本文探索了裂解气相色谱法作为植物种子分类表征方法的可能性。对豆科植物中不同属、不同亚属及相同亚属的共10种种子的裂解色谱图,用分区编码法进行区别,分析结果表明,不同种子最少有一个编码不同,方法简易快速,可为高等植物种子的区分提供一种佐证手段。     

羊蹄甲属植物种子的裂解色谱鉴定法研究

本文探索了裂解气相色谱法作为植物种子分类表征方法的可能性。对豆科植物中不同属、不同亚属及相同亚属的共10种种子的裂解色谱图,用分区编码法进行区别,分析结果表明,不同种子最少有一个编码不同,方法简易快速,可为高等植物种子的区分提供一种佐证手段。     

芸香甙热裂解研究

在 5 0 0℃和 770℃两种温度下 ,采用热解直接进样的方式 ,研究了烟草中主要的多酚类化合物———芸香甙的热裂解产物。分别鉴定出了 2 4个和 2 3个裂解化合物。通过比较和分析这两种温度下的裂解产物发现 ,芸香甙可以裂解产生大量具有香味的产物。不同温度下的热裂解产物中 ,其中有 16个热裂解产物是相同的 ,但它们的相对含量却不一样。     

裸子植物的生化系统学(四)——杉科植物的种子蛋白和针叶过氧化物酶

用SDS聚丙烯酰胺凝胶电泳分析了杉科全部10属共13种植物的种子蛋白多肽。它们 都有分子量为32、24和10K(千道尔顿)的多肽。每个分类群一般只有2至4个主要多肽,构 成种子蛋白总含量的一半;而且其分子量都分布在24—26K及29—36K两个区域内。 因此, 杉科植物种子蛋白谱与红豆杉科、三尖杉科相似,而不同于松科。属内不同种之间,种子蛋白 组成和针叶过氧化物酶电泳谱都没有看到显著差别。根据这两种蛋白质资料,表明杉科各属除红杉、巨杉、落羽杉相互很接近外,其他各属间关系都比较远。但是还不能说杉科可以分立几个科。     

5种裸子植物花粉外壁成分及结构分析比较

利用傅里叶变换红外光谱仪对银杏、日本冷杉等5种裸子植物的花粉外壁成分进行测定分析,结果表明,这5种裸子植物花粉外壁的红外光谱主要由蛋白质、脂类及多糖类物质的特征吸收峰组成。但不同科属间的花粉外壁主要成分含量存在较大差异,其中银杏科的银杏花粉外壁以蛋白质含量最为丰富;松科的雪松花粉外壁以脂类物质较为丰富;杉科的日本冷杉、杉木和日本柳杉花粉外壁成分以多糖类物质为主,但种间花粉外壁成分仍存在差异。采用扫描电镜观察5种裸子植物花粉,显示银杏、柳杉和杉木花粉粒体积较小,不具气囊,银杏花粉粒外壁表面具较均一条纹状纹饰,日本柳杉和杉木花粉粒外壁具颗粒状突起。雪松和日本冷杉花粉粒具气囊,体积较大,花粉外壁分别是粗糙具小穴状纹理以及表面光滑具微穿孔。     

2-L-酪氨酸-2-脱氧-D-葡萄糖的合成及其热裂解

以D-果糖和L-酪氨酸为原料合成了2-L-酪氨酸-2-脱氧-D-葡萄糖,用IR、~1H NMR、~(13)C NMR和HR-MS表征了产物的结构;采用热重-差热(TG-DTA)和在线裂解气相色谱/质谱联用(Py-GC/MS)技术研究了产物的热裂解。结果表明:1)合成产物为目标化合物;2)化合物裂解温度为153.01℃,600℃时样品总失重达到86%;3)裂解产物的数量随温度的升高而增多,裂解产物主要为杂环类、酮类、羧酸类、醛类和醇类等,这些物质表现出甜香、焦甜香、烘焙香、坚果香、花香和奶油香等香韵。     

松科系统学研究（I）

检以科的系统发育研究历来已久,但由于性状进货的不同步性和属间进化缺少中间环节,致使科的分类系统和各属之间的演化关系至今未得到令人满意的解决。本文在钻研已有文献的基础上,筛选出松科属间综合分类性状３６个,有序进化性状２０个,借助计算机,以属为分类单位,进行表征分析研究确定松科分类系统,结果将松科分为三个亚科：松亚科Ｓｕｂｆａｍ．Ｐｉｎｏｉｄｅａｅ：仅Ｐｉｎｕｓ Ｌｉｎｎ;落叶松亚科Ｓｕｂｆａｍ．Ｌａ     

杉木种子生理特性和地理变异（简报）

产地纬度较高的杉木种子发芽率高、涩籽率低,且有胚种子单宁含量较少,种子和胚的鲜、干重都较重,20～25℃为各产地种子的发茅适宜温度。各产地种子所含氨基酸种类变异不大。     

杉科植物的分类学研究

本文对杉科植物的研究历史作了回顾,根据分支分类结果和表征分类结果,提出了一个新的分类系统.以形态学为依据,结合其他学科的研究成果,对杉科的分类作了订正。作者承认杉科植物共9属、12种及3变种,将杉木、厚皮杉木、德昌杉木和米德杉木归并,支持柳杉作为日本柳杉的变种、台湾杉木作为杉木的变种、秃杉和台湾杉归并的观点。     

Thermal conductivity of functional citrus tree wood

Thermal conductivity coefficients have been determined for longitudinal and transverse flow in 4 varieties of fresh Citrus wood using steady state-methods. Equations were developed from which thermal conductivity could be rapidly estimated from moisture content or electrical conductivity. The heat balance of large and small tree trunks on a freezing night has been calculated on the basis of the coefficients.     

Object-based classification of land cover and tree species by integrating airborne LiDAR and high spatial resolution imagery data

We evaluated the effectiveness of integrating discrete return light detection and ranging (LiDAR) data with high spatial resolution near-infrared digital imagery for object-based classification of land cover types and dominant tree species. In particular we adopted LiDAR ratio features based on pulse attributes that have not been used in past studies. Object-based classifications were performed first on land cover types, and subsequently on dominant tree species within the area classified as trees. In each classification stage, two different data combinations were examined: LiDAR data integrated with digital imagery or digital imagery only. We created basic image objects and calculated a number of spectral, textural, and LiDAR-based features for each image object. Decision tree analysis was performed and important features were investigated in each classification. In the land cover classification, the overall accuracy was improved to 0.975 when using the object-based method and integrating LiDAR data. The mean height value derived from the LiDAR data was effective in separating “trees” and “lawn” objects having different height. As for the tree species classification, the overall accuracy was also improved by object-based classification with LiDAR data although it remained up to 0.484 because spectral and textural signatures were similar among tree species. We revealed that the LiDAR ratio features associated with laser penetration proportion were important in the object-based classification as they can distinguish tree species having different canopy density. We concluded that integrating LiDAR data was effective in the object-based classifications of land cover and dominant tree species.     

Thermal balance in composting operations

Thermal balance analysis of composting of sewage sludge cakes was conducted for a laboratory-scale batch operated autothermal packed bed reactor and a continuously operated commercial open-bin reactor with a scoop mixer, and necessary equations were developed. Substitution of experimentally determined reaction rates into them confirmed the validity of these equations. The relative importance of each term relating to heat removal from the reactors was quantitatively evaluated. In the commercial reactor, heat removal was mainly due to water vaporization from composting material, while in the laboratory reactor heat loss from the reactor wall was the largest. In the laboratory reactor, the amount of evaporation was largest when the air flow rate was controlled to maintain temperature in the reactor to maximize the reaction rate.     

Study of banana and coconut fibers Botanical composition, thermal degradation and textural observations

Four fibers from banana-trees (leaf, trunk) and coconut-tree (husk, fabric) were examined before their incorporation in cementitious matrices, in order to prepare insulating material for construction. Their botanical compositions have been determined following a method described previously. Thermal degradation of these fibers were studied between 200 and 700 degrees C under nitrogen gas flow. Temperature of pyrolysis was the experimental parameter investigated. The solid residues obtained were analyzed by classical elemental analysis, Fourier Transform Infra Red (FTIR) spectroscopy and were observed by Scanning Electron Microscopy (SEM). This study has shown (1) the relation between botanical, chemical composition with both localization of fibers in the tree and type of tree; (2) the rapid and preferential decomposition of banana fibers with increasing temperature of pyrolysis and (3) the rough samples are made of hollow fibers.     

Classification of Pinus massoniana and secondary deciduous tree species in northern subtropical region based on high resolution and hyperspectral remotely sensed data

Aims Using remote sensing data for tree species classification plays a key role in forestry resource monitoring, sustainable forest management and biodiversity research.Methods This study used integrated sensor LiCHy (LiDAR, CCD and Hyperspectral) to obtain both the high resolution imagery and the hyperspectral data at the same time for the natural secondary forest in south Jiangsu hilly region. The data were used to identify the crown and to classify tree species at multiple levels. Firstly, tree crowns were selected by segmenting high-resolution imagery at multiple scales based on edge detection; secondly, characteristic variables of hyperspectral images were extracted, then optimization variables were selected based on the theory of information entropy. Tree species and forest types were classified using either all characteristic variables or optimization variables only. Finally, tree species and forest types were reclassified along with the tree crowns information, and the accuracy of classification was discussed. Important findings Based on all available characteristic variables, the overall accuracy for four typical tree species classification was 64.6%, and the Kappa coefficient was 0.493. The overall accuracy for forest types classification was 81.1%, and the Kappa coefficient was 0.584. Based on optimization variables only, the overall accuracy for four typical tree species classification dropped to 62.9%, and the Kappa coefficient was 0.459. The overall accuracy for forest types classification was 77.7%, and the Kappa coefficient was 0.525. Obtaining both high resolution image and hyperspectral data at the same time by integrated sensor can increase overall accuracy in classifying forest types and tree species in northern subtropical forest.     

基于高分辨率与高光谱遥感影像的北亚热带马尾松及次生落叶树种的分类

利用遥感数据开展森林资源树种的分类对森林资源的监测、森林可持续经营及生物多样性研究都有重要意义。该文以江苏南部丘陵地区的北亚热带天然次生林为研究对象, 利用LiCHy (LiDAR、CCD、Hyperspectral)集成传感器同期获取的高分辨率和高光谱数据, 进行冠幅识别和多个层次的树种分类: 首先, 对高分辨率影像进行基于边缘检测的多尺度分割, 提取出单木冠幅; 其次, 对高光谱影像进行特征变量提取, 并对提取出的特征变量利用信息熵原理选取优化特征变量; 然后, 分别利用全部特征变量和经优化的重要特征变量对森林树种及森林类型进行预分类; 最后, 在预分类结果中加入单木冠幅信息对森林树种及森林类型进行重分类, 并分析分类结果的精度。研究表明: 1)利用全部特征变量进行4个典型树种分类时, 总体精度为64.6%, Kappa系数为0.493; 而针对森林类型的分类精度为81.1%, Kappa系数为0.584。2)利用选取的优化特征变量分类精度略低于利用全部特征变量的分类精度, 其中对4个典型树种分类时, 总体精度为62.9%, Kappa系数为0.459; 而针对森林类型的分类精度为77.7%, Kappa系数为0.525。通过集成传感器同期获取的高分辨率和高光谱数据可以有效地进行北亚热带森林的树种分类及森林类型的划分。     

Classification of pathogenic microbes using a minimal set of single nucleotide polymorphisms derived from whole genome sequences

In a context specific manner, Intra-species genomic variation plays an important role in phenotypic diversity observed among pathogenic microbes. Efficient classification of these pathogens is important for diagnosis and treatment of several infectious diseases. NGS technologies have provided access to wealth of data that can be utilized to discover important markers for pathogen classification. In this paper, we described three different approaches (Jensen-Shannon divergence, random forest and Shewhart control chart) for identification of a minimal set of SNPs that can be used for classification of organisms. These methods are generic and can be implemented for analysis of any organism. We have shown usefulness of these approaches for analysis of Mycobacterium tuberculosis and Escherichia coli isolates. We were able to identify a minimal set of 18 SNPs that can be used as molecular markers for phylogroup based classification and 8 SNPs for pathogroup based classification of E. coli.     

Thermal expansion of ZnSe by molecular dynamics simulation

Thermal expansion of bulk ZnSe crystal, grown by physical vapour transport technique, is experimentally measured for various temperatures and molecular dynamics simulation using a three body Tersoff potential is also developed for the same. The resulting expansivity compares well with our experimental results and other reported values.     

Protocell-like Microspheres from Thermal Polyaspartic Acid

One of the most prominent amino acids to appear in monomer-generating origin-of-life experiments is aspartic acid. Hugo Schiff found in 1897 that aspartic acid polymerizes when heated to form polyaspartylimide which hydrolyzes in basic aqueous solution to form thermal polyaspartic acid which is a branched polypeptide. We recently reported at the ISSOL 2005 Conference that commercially made thermal polyaspartic acid forms microspheres when heated in boiling water and allowed to cool. In a new experiment we heated aspartic acid at 180°C for up to 100 h to form thermal polyaspartylimide which when heated in boiling water without addition of base hydrolyzed to form thermal polyaspartic acid which upon cooling formed microspheres. Thermal polyaspartic acid microspheres appear protocell-like in the sense of being prebiotically plausible lattices or containers that could eventually have been filled with just the right additions of primordial proteins, nucleic acids, lipids, and metabolites so as to constitute protocells capable of undergoing further chemical and biological evolution. Thermal polyaspartic acid microspheres are extremely simple models of protocells that are more amenable to precise quantitative experimental investigation than the proteinoid microspheres of Sidney W. Fox. We present here scanning electron microscope images of such thermal polyaspartic acid microspheres. Figure 1 shows thermal polyaspartic acid microspheres from l-aspartic acid heated at 180°C for 50 h, at a magnification of 3,500×. Figure 2 shows thermal polyaspartic acid microspheres from the same sample at a magnification of 7,000×. The thermal polyaspartic acid microspheres have a diameter of approximately 1 μm These images were viewed with a Hitachi S2460N scanning electron microscope at 20 kV acceleration voltage. Figure 1 Thermal polyaspartic acid microspheres from l-aspartic acid heated at 180°C for 50 h, at a magnification of 3,500×.

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Figure 2 Thermal polyaspartic acid microspheres from l-aspartic acid heated at 180°C for 50 h, at a magnification of 7,000×.

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Presented at: National Workshop on Astrobiology: Search for Life in the Solar System, Capri, Italy, 26 to 28 October, 2005.