Composition Analysis and Identification of Ancient Glass Products Based on L1 Regularization Logistic Regression

In view of the composition analysis and identification of ancient glass products, L1 regularization, K-Means cluster analysis, elbow rule and other methods were comprehensively used to build logical regression, cluster analysis, hyper-parameter test and other models, and SPSS, Python and other tools were used to obtain the classification rules of glass products under different fluxes, sub classification under different chemical compositions, hyper-parameter K value test and rationality analysis. Research can provide theoretical support for the protection and restoration of ancient glass relics.

ANALYSIS OF STRUCTURE EVOLUTION AND ENVIRONMENTAL CONDITIONS OF TROPICAL CYCLONES OVER THE WESTERN NORTH PACIFIC DURING EXTRATROPICAL TRANSITION

Fifty-eight extratropical transition(ET) cases in the years 2000-2008, including 2,021 observations(at 6-hour intervals), over the western North Pacific are analyzed using the cyclone phase space(CPS) method, in an effort to get the characteristics of the structure evolution and environmental conditions of tropical cyclones(TCs) during ET over this area. Cluster analysis of the CPS dataset shows that strong TCs are more likely to undergo ET. ET begins with the increment of thermal asymmetry in TCs, along with the generation and intensification of an upper-level cold core, and ends with the occurrence of a lower-level cold core. ET lasts an average duration of about 28 hours. Dynamic composite analysis of the environmental field of different clusters shows that, in general, when TCs move northward,they are gradually embedded in the westerlies and gradually transform into extratropical cyclones under the influence of the mid-and higher-latitude baroclinic systems. As for those TCs which complete ET, there is always much greater potential vorticity gradient in the northwest of them and obvious water vapor transport channels in the environment.

Shrub Communities and Environmental Variables Responsible for Species Distribution Patterns in an Alpine Zone of the Qilian Mountains, Northwest China

Understanding the factors that drive variation in species distribution is a central theme of ecological research. Although several studies focused on alpine vegetation, few efforts have been made to identify the environmental factors that are responsible for the variations in species composition and richness of alpine shrublands using numerical methods. In the present study, we investigated vegetation and associated environmental variables from 45 sample plots in the middle Qilian Mountains of the northwestern China to classify different community types and to elucidate the species- environment relationships. We also estimated the relative contributions of topography and site conditions to spatial distribution patterns of the shrub communities using the variation partitioning. The results showed that four shrub community types were identified and striking differences in fioristic composition were found among them. Species composition greatly depended on elevation, slope, shrub cover, soil pH and organic carbon. The important determinants of species richness were soil bulk density and slope. No significant differences in species richness were detected among the community types. Topography and site conditions had almost equal effects on compositional variation. Nonetheless,a large amount of the variation in species composition remained unexplained.

Diversity and structural composition of species in dipterocarp forests:a study from Fasiakhali Wildlife Sanctuary, Bangladesh

Fasiakhali Wildlife Sanctuary is a protected area composed of tropical remnant rainforest that harbor substantial number of large,old Garjan（Dipterocarpus spp.）trees.The present study assessed composition,structure and diversity of the species in this protected area.A total of 32 trees species were recorded with DBH ≥ 11 cm belonging to 24 genera and 19 families.The forest is low in plant diversity as represented by Shannon–Wiener diversity and Simpson Dominance indices.Dipterocarpus turbinatus was the most dominant species with maximum relative density,frequency,dominance,and importance value index.Syzygium firmum and Tectona grandis followed in terms of dominance.The structural composition indicated higher number of individuals in the medium growth classes（41 to 〈 511 cm DBH and 16–20 m height ranges）,whereas D.turbinatus was the only species that dominated most of the growth classes.Poor stem density in lower growth classes indicated meager recruitment of regeneration which may be due to lower annual precipitation,increased grazing and encroachments.This study will help to understand the patterns of tree species composition and diversity in the remnant dipterocarp forests of Bangladesh.It will also contribute to identifying threatened plants to undertake D.turbinatus based conservation and sustainable management of the Fasiakhali Wildlife Sanctuary.

A coin-tap method of composite materials non-destructive testing based on improved grey clustering

Aiming at the problems of low reliability and complex operation of traditional coin-tap test of composite material,this paper introduces the grey system theory and achieves better performance.The response signals of coin-tap are classified through the grey clustering based on relation analysis,and corresponding improvements are made to the calculation method of the relation degree of nearness.First,the time history of acceleration is taken as the system behavior sequence.The improved correlation calculation method is used to solve the relation degree of nearness between the sequences,and the matrix of degree of grey relation is constructed based on this.Then,the sequence groups are summarized through the matrix,and the response signals of coin-tap are qualitatively classified according to the location of the reference sequence.Finally,the defect detection of composite materials is completed without pre-testing.The test results show that the accuracy of the coin-tap test based on improved grey clustering reaches 100%,which simplifies the operation steps while ensuring the reliability of the coin-tap test results.

Composition,Structure and Regeneration Dynamics of Olea ferruginea Royle Forests from Hindukush Range of Pakistan

Abstract＂ The abundance of Olea ferruginea in Malakand Division has been significantly reduced across its distribution range due to anthropogenic pressure in the recent past. A number of initiatives were taken for grafting this species to obtain better seeds for oil production, without the basic information on their ecology and management. To address this knowledge gap, we quantified the composition, structure and regeneration dynamics of Olea ferruginea forests in Malakand Division, Hindukush range of Pakistan. In the present study, five communities dominated by Oleaferruginea were identified using Ward＇s agglomerative cluster analysis. Total tree density ranged from 153-26o2 plants/ha, and basal area from 19.55 to 2353 m~ ha-1 with Olea having a relative density of 51% to 87% and basal area of 48% to 93%, respectively. The density of juveniles of the dominant and subordinate tree species were generally low which reflect their narrow distribution in the study area. Size-class distributions of O. ferruginea disclosed a bell-shaped pattern, indicating that forests were heavily exploited by local inhabitants in previous periods and recently by armed forces owing to security risks in the study area. The age （mean max. 300±34 years） and annual increment （3.2±1.2 years/cm） indicates that the species is long lived and generally slow growing among the different broad leaved species studied so far. However, the oldest trees can be found by the exploration of large diameter trees in the area. In addition, we found a stable linear relationship between the age and diameter （r2 = o.779）, indicating that diameter is a good predictor of age for this broad leaved species. In view of its relatively slow growth, longevity and positive ring-width characteristics O. ferruginea seems to be a suitable choice for dendroecological and dendrochronological studies in lesser Himalayan and Hindukush ranges of Pakistan. The results obtained from this study may help in understanding the composition, structure and regeneration dynamics of other subtropical broad leaved species.

基于密度聚类算法改进的语义主路径分析方法研究

语义主路径分析方法在改进传统主路径分析法中主路径内容单一、主题一致性较差等不足的同时,留下了两个缺陷,即所选主路径在语义空间的位置可能偏离主题聚簇中心、不同主路径的主题区分度并不明显。本文在语义主路径分析方法的基础上,提出一种逐步优化的主路径选择方法,即将主题聚簇密度和路径遍历权重进行叠加形成复合密度,通过调节复合密度中两个要素的比重来优化主题聚簇中心的定位,当聚簇中心的位置变化收敛后,将位于不同主题聚簇中心的路径作为结果输出。将本文方法分别用于电动汽车锂离子电池专利引文网络和材料科学领域高影响力论文引文网络,实验结果显示,本文方法所产生的多条主路径不仅在主题聚簇中的布局更加合理,而且选取不当主路径的可能性也大大降低,从而验证了本文方法的有效性。

钢-混组合结构群钉连接件的连杆效应试验研究

钢—混组合结构连接件中栓钉式群钉连接件存在单钉承载力折减及群钉中栓钉的剪力分布不均匀的情况,本文提出一种带连杆的群钉连接件,旨在通过在栓钉之间设置连杆使群钉中栓钉之间的剪力分布更加均匀,并提高构件的整体承载能力。利用推出试验结合有限元模拟,揭示了带连杆群钉连接件的作用机理,并通过参数分析给出群钉构件合理的连杆布置位置以及尺寸。研究结果表明:在构件达到极限承载力时,合理的设置连杆能够减少83.76%的栓钉底部剪力分布的不均匀程度,对构件承载能力的提升能达到8.56%。本文研究可为带连杆群钉连接件的结构优化提供一定的理论基础,推动新型连接件的发展。

不同年份白茶饼主要化学成分及感官品质变化与通径分析

分析不同年份白茶饼的主要化学成分与感官品质变化,以评价白茶饼储藏年份与感官品质的关系。以储藏2年陈至19年的白茶饼为试验材料,测定主要化学成分,结合感官评价,利用主成分分析、聚类分析、相关性分析、多元线性回归及通径分析,探讨主要化学成分与感官品质之间的关系。随着储藏年份的增长,茶多酚、游离氨基酸和茶红素含量呈下降趋势,最低值分别为50.71,5.78 mg/g和6.82 mg/g;而总黄酮、茶褐素呈上升趋势,最高值分别为62.18 mg/g和27.09 mg/g。主成分分析、感官分析表明,储藏4年的白茶饼的内质综合排名第1,感官品质最高(总分为96.8),具有最佳品质。聚类分析表明白茶饼储藏第2年、第4年和第6年时转化反应剧烈,而8~19年趋于稳定且感官品质逐渐上升。通径分析得出不同年份白茶饼感官品质的变化,咖啡碱含量与陈化白茶饼感官品质呈显著正相关,总黄酮含量呈显著负相关。白茶饼感官品质以储存4,10,19年的整体较佳。咖啡碱和总黄酮含量可作为评价陈年白茶饼品质的直接因素。

基于多纤维RVE和聚类分析的低温复合材料贮箱跨尺度计算

采用碳纤维增强复合材料贮箱可显著减轻运载火箭的质量,但贮箱在低温环境中机械-热载荷作用下的分析方法有待研究,尤其是要准确地考量纤维与基体间产生的细观热应力。采用包含多根纤维的代表体元模型,结合基体、纤维失效准则,建立了细观应力场及失效预测模型,并采用k-means聚类方法开展降维计算,提出了一种高效、高精度复合材料贮箱跨尺度分析方法。结果显示:该方法能够根据纤维和基体的热、力学常数准确地预测复合材料单层板的弹性常数和破坏强度;结合某贮箱模型,模拟了机械-热载荷共同作用下复合材料贮箱渗漏失效的发生过程,给出了明确的失效载荷及失效状态。

不同莲藕品种的营养品质分析与评价

探究不同莲藕品种的营养成分和活性成分,为莲藕品种筛选、加工利用及产品开发等提供支撑。通过测定7个莲藕品种的10个成分指标,采用主成分分析和聚类分析对不同莲藕品种营养品质进行综合评价,并建立莲藕营养品质评价模型。结果表明,大白胖的蛋白质含量(w,后同)(10.50%)和不溶性膳食纤维含量(12.13%)最高,鄂莲6号的脂肪含量(0.98%)最高,544的可溶性膳食纤维含量(6.35%)最高,八月粉的淀粉含量(65.59%)最高;莲藕整体呈现高淀粉、低脂肪且富含膳食纤维和蛋白质的特征。主成分分析结果表明,淀粉、脂肪、总酚和总黄酮含量累积贡献率达95.172%,可以用这4个主成分来综合评价莲藕营养品质的优劣,并建立莲藕综合营养品质评价模型F=0.692F1+0.308F2;综合得分表明鄂莲5号的品质最佳,小白胖的品质较差。

炮制对黄精蛋白氨基酸组成及营养价值的影响

该文以黄精生品和炮制品为研究对象进行蛋白质氨基酸的组成分析,利用主成分分析、聚类分析和t检验对样品中氨基酸组成进行差异分析;以联合国粮食与农业组织/世界卫生组织的氨基酸参考模式等为评价标准对黄精生品及炮制品进行蛋白质营养评价。结果表明,炮制前后黄精中均含有17种氨基酸,以鲜味氨基酸(谷氨酸、天门冬氨酸)含量最高,并含丰富的药效氨基酸、必需氨基酸、支链氨基酸等,是黄精提升菜品鲜美味觉和改善身体机能的重要营养物质。主成分分析和聚类分析均能将样品分为炮制品和非炮制品两类,表明炮制对黄精的蛋白氨基酸组成有着较大影响;与非炮制品相比,炮制品中丝氨酸、胱氨酸、赖氨酸和精氨酸显著降低,而蛋氨酸、异亮氨酸、缬氨酸、亮氨酸、苏氨酸、苯丙氨酸、脯氨酸和甘氨酸显著升高;功能性氨基酸则没有显著性变化,但必需氨基酸等均呈现显著升高,提示炮制后不仅能维持黄精的药效作用,还有助于其营养价值的提升。蛋白质营养评价结果显示,生品和炮制品的第一限制氨基酸分别为异亮氨酸和赖氨酸,且蛋白质营养价值大小比较为炮制品>生品,表明炮制加工有助于提升黄精的营养价值。

普洱生茶贮藏过程中品质指标的规律变化分析

该研究选用贮藏时间在3~20年的18个普洱生茶茶样,通过感官审评和理化成分分析,探究贮藏过程中普洱生茶品质指标的规律变化。结果表明,随着贮藏时间增加,普洱生茶的汤色色泽逐渐加深,香气由清香转为陈香,滋味由醇厚转为醇和,叶底颜色变深变暗,贮藏10年及以上感官品质有所提升,但贮藏18年后,感官品质开始下降;水浸出物、咖啡碱、GC、C、CG的含量呈不规则变化,没食子酸含量逐渐增加,游离氨基酸、EGC、EC、EGCG、GCG、ECG的含量随着贮藏时间的增加呈下降趋势。对17个品质指标标准化后进行相关性分析、主成分分析和聚类分析,发现品质指标间存在显著相关性,通过系统聚类可将茶样分为5类,每间隔3~4年聚为一类,其中,A类综合得分最高,D类次之,E类最低,说明品质指标随着贮藏年份的增加呈现下降趋势,且在3~4年贮藏时间内保持稳定。该结果为深入研究普洱生茶贮藏过程中的品质变化提供依据。

药食同源植物赤苍藤茎和叶成分比较研究

为科学利用赤苍藤资源,对赤苍藤不同茎级(0.5、1.6、2.7 cm)、部位(茎、叶)的总黄酮、蛋白质、维生素、矿质元素、各类氨基酸进行了测定与分析。结果表明,14种营养成分中叶的各类营养物质(除维生素B2)含量最高,其中茎类营养物质总黄酮、蛋白质和矿质元素氮、锌、铜、镁含量随着茎直径的增大而减少;维生素B1、维生素B2、铁、铜、锰的含量在茎直径为1.6 cm时最高;矿质元素磷、钙的含量随茎直径的增大而升高。茎中均检测出15种氨基酸,叶检测出16种氨基酸,叶比茎多检出蛋氨酸(Met)。4种样品所测各类氨基酸含量:叶>茎,其中含量排名前3的均为天门冬氨酸(Asp)、谷氨酸(Glu)、丙氨酸(Ala)。茎中天门冬氨酸(Asp)、丙氨酸(Ala)、酪氨酸(Tyr)含量随茎直径的增大而减少,3种茎中亮氨酸含量无变化;1.6 cm茎的支/芳值最高。氨基酸评分AAS、CS值,叶>茎,2.7 cm茎>1.6 cm茎>0.5 cm茎;EAAI指数:叶>茎,2.7 cm茎>1.6 cm茎>0.5 cm茎。从14种营养成分聚类分析上看,叶聚为一类,茎聚为一类。综合考量,在营养物质含量上叶明显高于茎,1.6 cm的茎质量最佳。本研究结果可为赤苍藤的茎、叶的高效利用提供科学参考。

Recharge sources and chemical composition types of groundwater and lake in the Badain Jaran Desert, northwestern China

Based on the analysis of ion chemical composition of lake water and shallow groundwater in the Badain Jaran Desert, this paper discussed the characteristics of ion chemical composition, spatial variation of lake water, and possible supply sources of lake water and groundwater in the desert areas. The results show that the pH, salinity, TDS and electrical conductivity of the lake water are greater than those of groundwater. The ion contents of water samples are dominated by Na^＋ and Cl^-. Most of the higher salinity lakes are Na （K）-CI-（SO4） type, and a few of low salinity lakes belong to the Na-（Mg）-（Ca）-Cl-（SO4）-（HCO3） type. Most of the groundwater is Na-（Ca）-（Mg）-Cl-（SO4）-（HCO3） type, attributed to subsaline lake, and only a few present the Na-Cl-SO4 type, flowing under saline lake. The pH, salinity, TDS and electrical conductivity in the southeastern lakes are relatively low, and there are slightly alkaline lakes. The pH, salinity, TDS and electrical conductivity in the northern lakes are much greater than those of the southeastern lakes, and the northern lakes are moderately alkaline and saline ones. In the southeastern part of the Badain Jaran Desert, the ion chemical characteristics of the lake water from south to north show a changing trend of subsaline →saline→hypersaline. The changing trend of chemical compositions of ions in recent 9 years indicates that most of the ion contents have a shade of reduction in Boritaolegai, Badain, Nuoertu and Huhejilin lakes, which state clearly that the amount of fresh water supply is increasing in the 9-year period. The ion chemical composition of the lake water reveals that the flow direction of lake water is from southeast to northwest in the Badain Jaran Desert. The ion chemical composition, moisture content of sand layer water level height and hierarchical cluster analysis of the lake water and groundwater demonstrate that the lake water is mainly supplied by local rainfall and infiltration of precipitation in Yabulai Mountains and Heishantou Mountain, and the supply from the Qilian Mountains is almost impossible.

基于超微消解结合电感耦合等离子体质谱法的核桃产地溯源

目的探究6种产地来源核桃中20种矿物质元素与种植区域的相关性,实现产地溯源。方法样品经超微消解仪处理后,利用电感耦合等离子体质谱仪测定20种矿物质元素含量,对数据进行主成分分析,筛选出特征元素,并对特征元素与种植区域的相关性进行系统聚类分析。结果核桃样品中20种矿物质元素检测方法的线性关系良好,相关系数大于0.99,检出限为0~24.23μg/L,该方法的精密度、稳定性的相对标准偏差均小于7.4%,样品加标回收率为80.4%~119.3%、相对标准偏差为2.1%~7.9%(n=3)。6种产地来源核桃样品中,常量元素由高到低是K、Mg、Ca,大部分样品微量元素含量由高到低为Mn、Fe、Zn、Cu。主成分分析确定Na、Sr、Mn、Cu、Rb、Ni、Zn、Al和Cs 9种元素为甘肃徽县、陕西商南县、四川盐边县、云南漾濞县、新疆喀什及阿克苏地区共36批核桃中矿物质元素的特征成分。结论主成分分析和特征元素分析发现不同产区核桃元素含量的差异较大,本研究可以应用在核桃产地鉴定中,为核桃的产地溯源体系建设提供参考和技术支持。

寒地水稻开花期多雨寡照复合逆境灾损评估指标

黑龙江省是中国优质粳稻生产核心种植区,开花期多雨寡照复合发生,严重影响寒地水稻结实率和产量。为了保障国内优质稻米的供应及国家粮食安全,本研究旨在构建一个针对多雨寡照复合发生的判识指标,并定量评估其对产量的损失。通过整合气象数据、水稻生育期信息、产量资料以及历史灾情记录,运用多层灰色关联分析法探究致灾因子、作物产量结构与相对气象产量之间的灰色映射关系。据此,建立了寒地水稻多雨寡照复合指数(RSCI)和一个描述复合逆境与产量损失率关联度的模型。利用K-均值聚类分析方法和历史典型灾害年份数据确定了灾害的临界值和等级,进而形成了评估多雨寡照复合发生导致产量损失的评估指标体系。本研究明确了寒地水稻在不同等级(轻度、中度、重度)多雨寡照条件下的临界阈值和相应的产量损失率,历史灾情验证显示多雨寡照判识率达到100%,产量损失率判识准确率超过80%。在1958—2021年间,全省水稻不同程度多雨寡照的发生频率呈轻度高于中度高于重度的趋势,且北部农区的发生频率高于南部农区。该研究成功构建了一套多雨寡照复合发生的判识指标,为定量化评估产量损失提供了重要的技术支撑。

Application of cluster analysis to geochemical compositional data for identifying ore-related geochemical anomalies

Cluster analysis is a well-known technique that is used to analyze various types of data. In this study, cluster analysis is applied to geochemical data that describe 1444 stream sediment samples collected in northwestern Xinjiang with a sample spacing of approximately 2 km. Three algorithms （the hierarchical, k-means, and fuzzy cmeans algorithms） and six data transformation methods （the z-score standardization, ZST; the logarithmic transformation, LT; the additive log-ratio transformation, ALT; the centered log-ratio transformation, CLT; the isometric log-ratio transformation, ILT; and no transformation, NT） are compared in terms of their effects on the cluster analysis of the geochemical compositional data. The study shows that, on the one hand, the ZST does not affect the results of columnor variable-based （R-type） cluster analysis, whereas the other methods, including the LT, the ALT, and the CLT, have substantial effects on the results. On the other hand, the results of the row- or observation-based （Q-type） cluster analysis obtained from the geochemical data after applying NT and the ZST are relatively poor. However, we derive some improved results from the geochemical data after applying the CLT, the ILT, the LT, and the ALT. Moreover, the k-means and fuzzy cmeans clustering algorithms are more reliable than the hierarchical algorithm when they are used to cluster the geochemical data. We apply cluster analysis to the geochemical data to explore for Au deposits within the study area, and we obtain a good correlation between the results retrieved by combining the CLT or the ILT with the k-means or fuzzy c-means algorithms and the potential zones of Au mineralization. Therefore, we suggest that the combination of the CLT or the ILT with the k-means or fuzzy c-means algorithms is an effective tool to identify potential zones of mineralization from geochemical data.

基于气相色谱法的奇亚籽油脂肪酸指纹图谱构建及其掺伪鉴别

目的基于气相色谱法(gas chromatography,GC)构建奇亚籽油的脂肪酸标准指纹图谱,并对奇亚籽油进行掺伪鉴别。方法以奇亚籽为研究对象,采集30批次来自多个产地的奇亚籽油作为样本,对其脂肪酸进行GC分析,通过“中药色谱指纹图谱相似度评价系统”建立奇亚籽油脂肪酸标准指纹图谱,据此鉴别掺伪量分别为10%、20%、30%、40%、50%的菜籽油、玉米胚芽油、芝麻油、花生油、葵花仁油和大豆油的掺伪模型。结果奇亚籽油所含脂肪酸以棕榈酸、硬脂酸、油酸、亚油酸、花生酸、γ-亚麻酸、α-亚麻酸为主;通过相似度评价30批次奇亚籽油的相似度均大于99.5%;聚类分析结果将30批次奇亚籽油按不同产地分为6大类;利用指纹图谱可以鉴别掺伪量10%及以上菜籽油、玉米胚芽油、芝麻油、葵花仁油、大豆油掺伪模型,20%及以上花生油掺伪模型。结论本研究通过分析奇亚籽油脂肪酸组成并建立气相色谱脂肪酸标准指纹图谱,为鉴别纯奇亚籽油提供了一定的数据及技术支撑。

心脑欣片HPLC指纹图谱建立及7种成分测定

目的:建立心脑欣片HPLC指纹图谱,并测定红景天苷、酪醇、没食子酸、没食子酸乙酯、对香豆酸、咖啡酸和绿原酸的含量。方法:心脑欣片75%甲醇提取液的分析采用WondaSil C18-WR色谱柱(4.6 mm×250 mm,5μm);流动相为甲醇(A)-0.1%磷酸(B),梯度洗脱;流速为1.0 mL/min;柱温为35℃;检测波长为275 nm;进样量为20μL。对心脑欣片HPLC指纹图谱进行聚类分析、主成分分析。以没食子酸为内标,采用一测多评法测定多种成分含量。结果:11批样品中HPLC指纹图谱中有24个共有峰,相似度均大于0.960。各批次样品分为3类,4个主成分累积方差贡献率达95.045%,7种成分在各自范围内线性关系良好(r≥0.995),平均加样回收率为96.76%~104.02%,RSD值为0.05%~1.48%。一测多评法结果与外标法接近。结论:该方法简单可靠、重复性好,可用于心脑欣片的质量控制。