差分拉曼光谱法对塑料瓶的鉴别分析

利用差分拉曼光谱对收集的42个不同品牌不同厂家不同容量的塑料瓶进行检验,根据差分拉曼光谱图可将样品分为聚乙烯与聚对苯二甲酸乙二醇酯两大类,每类样品的拉曼特征峰存在一定差异。使用判别分析法对处理后的光谱数据进行分析,建立8个判别函数,实现对数据变量取值的预测,同时检验上述判别函数的判别能力,并建立判别分布图,判别图中9组样品质心明显区分,效果较好。对拉曼光谱数据进行系统聚类、K-Means快速聚类和皮尔逊相关系数分析,验证判别结果的准确性,为塑料瓶类物证的检验提供依据,可用于公安实际办案。     

差分拉曼光谱结合化学计量学对白色购物纸袋的检验研究

目的 建立差分拉曼光谱用于无损识别白色购物纸袋的方法。方法 对收集到的60种不同品牌、不同规格的白色购物纸袋进行拉曼光谱测定,对样品的拉曼光谱图进行预处理,根据光谱图对样品进行初步分类,并结合化学计量方法对样品进行分组。应用Fisher判别分析方法对分类结果进行验证。最后应用RBF模型对未知样本进行分类判别。结果 结合样品中所含的碳酸钙、滑石粉、硫酸钡的不同,可初步将白色购物纸袋样品分为五大类,采用K-均值聚类方法继续细分,通过Fisher判别方法对样品分结果进行验证,判别准确率为100%。应用神经网络RBF模型对未知样本进行判别分析,准确率达到89.48%。结论 该方法简便易行,为白色购物纸袋的分类提供了科学的依据,也为公安基层工作的开展提供了便捷的办法。     

基于随机森林利用差分拉曼光谱对塑料食品包装瓶的分类研究

目的 建立一种快速无损的检验塑料食品包装瓶的分析方法,提供一种快速分类模型。方法 利用差分拉曼光谱对100个塑料食品包装瓶样品进行检验,根据样品的差分拉曼特征峰可以对样品进行分类,样品可被分成聚对苯二甲酸乙二醇酯和聚丙烯两大类,对其中数目较多的第I类继续根据样品中所含填料的不同进行分类。利用贝叶斯判别、多层感知器和随机森林算法分别构建分类模型对继续分类结果进行分析验证。结果 第I类样本可继续被分为4类,贝叶斯判别结合留一交叉验证法分类正确率为71.7%,多层感知器神经网络分类模型的训练集和测试集分类正确率分别为100%和86.2%,随机森林分类模型的训练集和测试集分类正确率分别为100%和96.5%。通过比较发现,差分拉曼光谱与随机森林算法相结合可以对塑料食品包装瓶实现有效的分类。结论 该方法简单快速,样品用量少且无损样品,可为塑料食品包装品的物证鉴定提供科学依据。     

差分拉曼光谱法结合聚类分析检验食品塑料包装盒

目的 建立一种高效、无损、准确的区分检验食品塑料包装盒的方法.方法 采用SERDS Porta-ble-Standard便携式差分拉曼光谱仪,在激发光源为785 nm,激光功率为380 mW,扫描时间为10 s,扫描范围为250～2800 cm-1的实验条件下,对53个不同来源、不同品牌的食品塑料包装盒样品进行测量,对得到的差分拉曼光谱数据进行凝聚性系统聚类分析,并结合皮尔逊相关性系数对其进行检验,对食品塑料包装样品进行区分.结果 53个样品根据差分拉曼谱图被分为7类,根据不同样品的差分拉曼特征峰聚类结果将32个PP类样品分为4类.结论 该方法无损检测、操作便捷、实验结果稳定,可以为微量物证检验和侦查破案提供一定帮助.     

基于差分拉曼光谱对烟盒物证检验

目的 为了探究一种基于光谱分析的检验方法,以达到快速准确地区分检验烟盒物证的目的.方法 采用便携式差分拉曼光谱仪,对39个不同的黄色烟盒样本进行测试,取得各样本的差分拉曼光谱数据.根据烟盒填料种类对样本进行初步分类,再结合化学计量学,通过IBM SPSS Statistics 26.0软件,在主成分分析法对数据进行降维的基础上,对测量结果进行系统聚类和K-Means聚类.结果 39种样本依据填料种类可以区分为3类,结合化学计量学可以更准确地区分为6类.结论 该方法无损检材、快捷准确,且图谱不受荧光干扰,结合化学计量学方法可以对烟盒样本进行分类检验,此方法为公安机关在犯罪现场检验此类物证提供了依据.     

吲哚类合成大麻素的差分拉曼光谱分析

建立一种简便快速、准确可靠、无损检材的检验合成大麻素类新精神活性物质的方法-差分拉曼光谱法。利用手持式差分拉曼光谱仪,在激光光源785 nm,激光功率200 mW,积分时间1 s,扫描范围为2 400～200 cm–1的条件下,对17种吲哚类合成大麻素标准品进行检验。首先对样本进行人工分类,利用系统聚类法将17个样本分为4组,与人工分类结果较为一致。再运用Fisher判别分析构建4个判别函数对样本分类结果进行验证,准确率为94.1%。可以根据差分拉曼光谱的数据对17种合成大麻素类物质进行区分。利用该方法可以对吲哚类合成大麻素进行快速无损的检验,并可用于公安机关实际办案。     

包装机械手轨迹规划和控制系统设计

目的 针对常见分区域图像修复算法中,对于待修复目标的分离效果不佳而导致的修复效果较差等问题,提出一种基于改进K均值聚类的图像修复方案。方法 首先将待分割图像转换到CIELab颜色空间,对a,b分量进行聚类运算,得到K个聚类中心,通过改变聚类迭代次数,得到粗分割结果;然后采用数学形态学对分割结果进行细化处理,精确分离得到目标对象和背景;最后,采用Reinhard算法对目标和背景分别进行色彩迁移,得到图像修复结果。结果 所提模型中的区域分割算法,其分离效果均优于经典的分水岭算法、最大类间方差法和基于Lab通道的最大类间方差算法,采用Reinhard色彩迁移算法图像修复结果比较接近理想修复效果。结论 由最终结果可知,提出修复法的整体效果较为理想,且优于传统的分区域图像修复算法,可为生产实践提供必要的理论依据。     

差分拉曼光谱结合XRF对塑料药瓶的多元分类研究

目的 构建一种药瓶的分类及预测模型。方法 利用差分拉曼光谱和X射线荧光光谱对54个不同品牌和产地的塑料药瓶进行分析检验。结果 得到了54个样品的差分拉曼谱图及Cl、Ca、Ti、Fe、Zn等元素的含量。利用主成分分析对差分拉曼光谱数据进行降维,再利用系统聚类将降维后的数据分为8类,并以此为依据建立判别分析模型,最终判别模型经交叉验证可知准确率达到90.7%,多层感知器的分类准确率为100%,分类效果较好。结论 差分拉曼光谱可以根据谱图中的特征峰推断样品的分子结构,并且可以根据峰位对样品进行分类,并建立分析模型,X射线荧光光谱可以通过各元素的种类和含量的不同对样品进行区分,实现组内的细化。差分拉曼光谱和X射线荧光光谱可以分别从有机和无机的角度对药瓶进行分类,在分析上可以优势互补,可为公安机关实际办案探索出一种新的光谱联用角度和方法。     

差分拉曼光谱对香水样品的分类研究

为建立一种快速检验香水样品的方法,利用SERDS Portable Base型差分拉曼光谱仪对26个香水样品进行无损检测分析。首先,根据1 044 cm^-1,1 274 cm^-1,1 454 cm^-1三处差分拉曼光谱特征峰差异可将样品归为4个类别,利用Pearson系数进行相关性分析验证分类的准确性。最后,通过主成分分析(PCA)对差分拉曼光谱数据进行降维,并根据提取出的前三个主成分构建径向基函数(RBF)神经网络,选取80.8%的样本用于训练,19.2%的样本用于测试集,分类准确率达100%。结果表明,PCA-RBF模型结合可以为香水物证鉴别研究提供依据,该方法无损检材且准确度高。     

基于多元分析的食用油油桶差分拉曼光谱的分类研究

目的对纵火类案件现场所遗留食用油油桶物证进行快速无损检验及区分,为公安机关侦查破案提供线索。方法采用最新的差分拉曼光谱技术对26个食用油油桶及桶盖,共计52个样品进行检验。首先,通过传统谱图分析对2类样品进行初步分类,同时,结合多元分析,对桶盖进行分层聚类,对桶身再利用Gap statistic算法确定k值的基础上K-means聚类分析。结果成功将桶盖分为了3类,桶身分为3类,且对桶盖和桶身所得分类结果都与已知样品所属类别一致。结论此方法可对食用油油桶进行快速无损检验及区分,为现场遗留有食用油油桶的纵火案件侦破提供一定的帮助。     

基于神经网络的塑料打包带高光谱模式识别

目的 建立一种快速、准确、无损的塑料打包带的检验及分类方法。方法 利用高光谱在波长为350～990 nm的条件下采集52个不同来源的塑料打包带样品的高光谱数据,并对样品进行Savitzky-Golay平滑处理,同时结合主成分分析对样品进行降维。将提取到的主成分进行K-Means聚类,以聚类结果为依据建立径向基函数神经网络（RBFNN）与BP神经网络模型（BPNN）。结果 打包带样品的高光谱谱图在400～500 nm、600～700 nm处有较大区别。实验共提取了5个初始特征值大于1的主成分,可以解释96.633%的原始数据。通过K-means聚类将塑料打包带样品分为6类,Calinski-Harabasz指数为28.76,RBFNN分类准确率为86.7%;BPNN分类准确率为98.1%,BPNN的分类效果更好。结论 研究表明神经网络在高光谱谱图分类处理上具有较高的准确度,同时也验证了高光谱在区分检验塑料打包带类物证的可行性与科学性,为公安机关提供了一种新的检验方法。     

Effect of textured eye drop bottles on the photostability of pranoprofen 0.1% ophthalmic solution

Context: Ophthalmic solutions are usually filled in a plastic bottle due to its durability and disposability. In Japan, photostability is one of the concerns for the quality control because an eye drop bottle must be a transparent container.

Objective: The present work studied the effect of textured eye drop bottles on its light blocking to improve the photostability of ophthalmic solutions.

Materials and methods: We investigated the photostability of Pranoprofen ophthalmic solution filled in a variety of textured eye drop bottles. Pranoprofen content was analyzed by high-performance liquid chromatography and surface structure of textured eye drop bottles was evaluated by transmittance, calculated average roughness (Ra) and haze intensity.

Results: We observed that eye drop bottle which had greater than Ra value of 1.0?µm and haze intensity 62% clearly showed photostability improvement.

Conclusions: This report is the first one which shows that photostability of ophthalmic solution is improved by using textured eye drop bottle. Moreover, this approach is a simple and effective method to improve the photostability. This method is available for not only various ophthalmic applications but also other liquid pharmaceuticals or food products.     

Fracture toughness of selectively reinforced Al2124 alloy: precrack tip in the aluminium alloy side

Abstract

The fracture toughness of Al2124/Al2124+SiC bimaterials is affected by thermal residual stresses, elastic/plastic mismatch, precrack tip position, and failure mechanism. When the precrack tip is in the Al2124 side, final catastrophic failure occurs when ductile fracture of the Al2124 layer between the precrack tip and the composite side takes place, followed by fracture of the composite layer. For a precrack tip 2·0 mm from the interface, K _Q(5%) values are lower than the 'Al2124 only' value due to the near crack tip tensile residual stresses and higher stress triaxiality within the Al alloy ligament. At 0·5 mm from the interface, K _Q(5%) values increase and are usually as high as the 'Al2124 only' value due to the stronger shielding of the elastic/plastic mismatch. If the precrack tip is 2·0 mm from the interface, K _crit values of the bimaterial are higher than the 'Al2124 only' value and this is deduced to be due to the elastic/plastic mismatch shielding. At 0·5 mm from the interface, K _crit values are reduced because both the near tip tensile residual stress is higher and stress triaxiality levels of the ductile ligament are higher, although the elastic/plastic mismatch shielding is also higher at this position.     

Study of Eye Drops Dispensing and Dose Variability by Using Plastic Dropper Tips

ABSTRACT

The application of eye drops from flexible dropper bottles fitted with different types of dropper tips is associated with the high variability of eye drop weights. The aim of this report was to investigate the simultaneous effect of three factors influencing the mean weight of drops dispensing from two plastic dropper tips. Using a designed experiment (Box-Behnken), the effect of the concentration of benzalkonium chloride solutions (BAC) in the range of 0–0.02%, the dispensing angle from 90° to 30° from horizontal, and the residual volume of liquid in the dropper bottle from 4 to 10 mL on the mean drop weights were examined. The significant effect of the increase in BAC concentration resulted in a linear decrease in drop weights for both of the dropper tips investigated. The significant effect of the dispensing angle was influenced by the dropper tip design. For the dropper tip A, the effect of the dropper tip tilt was described by the quadratic equation with a minimum, which corresponded to the dispensing angle equal to that of 48° from horizontal. Below this angle, the increase in drop weights occurred due to the drop formation from the wetted external surface of the tip orifice. The linear decrease in drop weights in response to the decrease in dispensing angle was detected for the dropper tip B. The regression equations and the contour line plots obtained allowed the drop weights to be estimated for the actual combinations of both the BAC concentration and the dispensing angle. The effect of the residual volume was found to be non-significant. Based on the formula of Tate's law, the direct proportion between surface tension of a solution and the radius of the effective perimeter of a dropper tip can be used to estimate the theoretical maximal weight of drops at the dispensing angle of 90°. Using the stalagmometric values of surface tension of the BAC solutions, the maximal drop weights were estimated for both of the dropper tips investigated. A comparison between the theoretical and the experimentally measured drop weights enabled the dropper tips behavior to be discussed by using Harkins and Brown correction factor F. The F-value of 0.74 noted for the dropper tip A differed from that of stalagmometer F-value (0.61) indicating a deviation from the simple drop formation process in answer to more complicated design of the dropper tip A. On the other hand, the F-value of 0.6 observed for the dropper tip B demonstrated the better consistency with stalagmometry. As a result, the dropper tip B with the linear decrease of drop weights in response to the increased concentration of BAC and the decreased dispensing angle without the adverse external drop formation could be recommended in real drop dispensing.     

A Direct Data-Cluster Analysis Method Based on Neutrosophic Set Implication

Raw data are classified using clustering techniques in a reasonable manner to create disjoint clusters. A lot of clustering algorithms based on specific parameters have been proposed to access a high volume of datasets. This paper focuses on cluster analysis based on neutrosophic set implication, i.e., a k-means algorithm with a threshold-based clustering technique. This algorithm addresses the shortcomings of the k-means clustering algorithm by overcoming the limitations of the threshold-based clustering algorithm. To evaluate the validity of the proposed method, several validity measures and validity indices are applied to the Iris dataset (from the University of California, Irvine, Machine Learning Repository) along with k-means and threshold-based clustering algorithms. The proposed method results in more segregated datasets with compacted clusters, thus achieving higher validity indices. The method also eliminates the limitations of threshold-based clustering algorithm and validates measures and respective indices along with k-means and thresholdbased clustering algorithms.     

Evaluation of a system for chemical sterilization of packages

A system was evaluated for the chemical sterilization of packages, based on its sporicidal efficiency using inoculated Bacillus subtilis inside polyethylene terephthalate (PET) bottles. Different combinations of contact time, temperature and peracetic acid concentrations were tested, delineated according to a factorial planning of 2³. The results, expressed as decimal reduction counts, proved that peracetic acid showed good sporicidal efficiency at 1.2% concentration in the temperature range 30–50°C. With this performance, the tested system can be used to sterilize plastic bottles and other similar packages, achieving a count reduction of spores by up to 10^?7. Copyright © 2004 John Wiley & Sons, Ltd.     

A novel ion-activated in situ gelling ophthalmic delivery system based on κ-carrageenan for acyclovir

The aim of this study was to prepare and evaluate ion-activated in situ gel ophthalmic drug delivery system based on κ-carrageenan (KC), using acyclovir as a model drug, hydroxypropyl methylcellulose (HPMC) as the viscosity agent and hydroxypropyl-β-cyclodextrin (HP-β-CD) as the penetration enhancer. The two ternary phase diagrams exhibited the effect of K⁺ and Ca²⁺ on the sol-to-gel transition, which turned out that KC was more sensitive to K⁺. The optimal ophthalmic matrix (prepared from KC and HPMC) was optimized with in vitro drug release test. The apparent permeability coefficient of acyclovir under 2% HP-β-CD was found to have dramatically increased (2.16-ploid) than that of conventional eye drops (p?in situ gel based on KC significantly delayed drug release and its bioavailability could be improved in comparison with the conventional eye drops. Hence, it has the potential to be a novel kind of ocular drug delivery system.     

Ground Nephogram Recognition Algorithm Based on Selective Neural Network Ensemble

In view of the low accuracy of traditional ground nephogram recognition model, the authors put forward a k-means algorithm-acquired neural network ensemble method, which takes BP neural network ensemble model as the basis, uses k-means algorithm to choose the individual neural networks with partial diversities for integration, and builds the cloud form classification model. Through simulation experiments on ground nephogram samples, the results show that the algorithm proposed in the article can effectively improve the Classification accuracy of ground nephogram recognition in comparison with applying single BP neural network and traditional BP AdaBoost ensemble algorithm on classification of ground nephogram.