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霉变花生极有可能含强致癌物质-黄曲霉素,快速识别并分离霉变花生可从源头上阻止其进入食物链,并降低人类摄入黄曲霉素的风险。利用可见光-近红外高光谱数据,通过光谱分析确定能有效识别霉变花生的光谱特征或指数模型。共获取霉变花生样本253个,健康花生247个,并取其霉变(或健康)部位的均值光谱。在对光谱进行连续统去除后,首先对其求取了不同步长的一阶微分,并在可分性较优的光谱区域计算了Area500~650指数;其次,用连续小波变换提取了光谱的形状和位置信息,并利用Indexcwt指数识别霉变花生样本。结果显示,指数Area500~650的J-M距离为1.95,Indexcwt模型的J-M距离为1.99,表明霉变和健康花生在构建的指数模型Area500~650和Indexcwt的特征空间可分性均较优。  相似文献   

3.
光谱分析技术以其简便、快速、高精度和无损测定等优越性,成为获取烟草和食品信息的重要手段.国内相关研究起步较晚,在近几年内,才涌现出了大量的有关烟草和食品研究报告,研究的范围也渐趋广泛,并综合分析了烟草成分测定、食品真伪鉴别、食品的定性鉴别的应用.因此,光谱分析技术的应用前景是非常广泛的,值得深入研究.  相似文献   

4.
矿物组分快速定量提取模型及其应用   总被引:2,自引:0,他引:2  
矿物成分快速鉴定是提高遥感矿产勘探、遥感矿物填图以及诸多地学研究等工作效率的关键。由于技术等各方面的限制,国内外针对矿物快速分析的模型和软件较少。20世纪90年代以来近红外光谱仪在技术上的突破和计算机的发展使得近红外光谱技术在矿物快速识别领域的应用变得可行,先后出现了基于吸收位置的反演模型(模型一)和基于波形匹配的反演模型(模型二)。文章提出了特征光谱线性反演模型。经美国地质调查局矿物光谱库(USGS)端元混合实验数据验证,该模型精度接近100%,远优于模型一和二。对新疆包古图地区地表随机所采23个样本分析,该模型平均精度为64.6%,另外两模型分别为:33.8%和8.1%,优于模型一和二。虽精度尚低于传统镜下鉴定方法,该模型具有高效、方便、工作量小、人为误差小等优点,已初步应用于新疆包古图地区遥感矿产勘探工作,有较好的推广前景。  相似文献   

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Abstract

Integrated investigations on infrared spectroscopic characteristics of metabolites and on applications of infrared spectroscopy to foodstuff production, food processing, and tasting are described. As the important metabolites, saccharides, which play very important roles in various functions, located in the central position of the metabolic pathways, were selected, and the spectral features of the saccharides and related materials are discussed. Additionally, the applications of spectral analysis to the monitoring of the enzyme reaction and the sugar metabolic processes, which are the main materials in food processing, are described. Furthermore, the studies on the spectroscopic measurements during the cultivation of agricultural products as foodstuffs and in the tasting as the final quality evaluation of foods are represented. These results suggest that infrared spectroscopy could be very effective for evaluating foodstuff production and the tasting of the processed foods and that the applied topics should provide fundamental information about the spectral behavior of the metabolites and bioproducts.  相似文献   

6.
静电纺丝技术是采用物理方法制备一维采用纳米纤维的有效方法,它在大规模制备有序的、复杂的一维纳米材料方面具有很强优势。除了制备一维纤维材料外,电纺丝技术还用于制备二维和三维多孔结构的材料。本文分为三部分,首先介绍了静电纺丝技术的原理和方法;然后综述了静电纺丝技术在制备一维材料方面的研究进展,最后列举了静电纺丝技术在生物工程领域的应用。  相似文献   

7.
A survey is presented of some of the recent uses of Mössbauer spectroscopy in studying chemical changes in mineral systems. The changes considered include those occurring naturally, such as weathering, leaching, soil formation, lake and river sedimentation and coal oxidation, and some induced by man, such as chemical leaching, precipitate ageing, coal hydroliquefaction and ash resulting from coal combustion.  相似文献   

8.
NMR指纹图谱与模式识别方法   总被引:4,自引:0,他引:4  
NMR指纹图谱与模式识别方法相结合在食物的研究中得到广泛应用,已经成功应用于食品的产地的区分,质量判定和转基因食品的安全考察等领域中. 本文综述了近些年NMR指纹图谱与模式识别方法在这些领域的应用.   相似文献   

9.
利用X射线衍射、X射线荧光光谱及红外吸收光谱对墨脱县北侧和格林村两处洪积扇滑坡面内采集的滑带土样品测试,分析了的主要矿物、黏土矿物的组成和含量及其化学成分。结果表明,滑带土中主要矿物组成受洪积扇组分控制,其黏土矿物含量分别占9%和10%,墨脱县附近滑动面中滑带土样品的黏土矿物含大量的伊利石,反应出该滑坡事件在很短的时间内完成,滑坡体滑动速率非常高;两处滑带土样品的红外吸收光试均未发现CO2-3,HCO1-3或C—H等振动相应产生的吸收峰,表明洪积扇滑动之后,滑坡面处于封闭系统,没有力学性质较差的碳酸盐等外来矿物或含腐蚀质的次生黏土沿滑动面充填进去,其结果增加了滑坡体的稳定性;样品中含有一定量的埃洛石,反应了区域洪积扇发育在非常潮湿温暖的环境中,同时封闭体系内滑带土所含的Na2O和CaO等化学组分不能通过淋滤作用排出,滑坡面内发生强烈的水-岩相互作用,促使其内部的黏土矿物发生伊利石-伊利石/蒙脱石混层-蒙脱石趋势的转化,导致格林村附近滑坡面内的滑带土中含大量后期分解形成的伊利石/蒙脱石混层。该类黏土矿物组合很大程度上降低了滑带的摩擦强度值,从而提高了再次发生滑坡的危险性。  相似文献   

10.
光无线技术及其应用   总被引:1,自引:0,他引:1  
通信领域对带宽越来越大的需求正推动着传统无线通信技术的发展。虽然光通信系统和光网络能为人们提供极大的带宽,但这也意味着必须能开发出来新的设备和系统。半导体发光二极管(LED)被认为是未来在建筑、汽车和飞行器上的主要光源。相比于白光光源和荧光光源,LED能提供更高的能量效率,且由于其出色的节能性能,LED在目前全球性的二氧化碳减排行动中也扮演着重要的角色。另外,激光器目前也处在于LED类似的情形中。这些核心器件的出现很可能会大大改变我们对光的使用,不仅是在照明方面,还包括通信、传感、导航、定位、监控和成像等各个方面。  相似文献   

11.
太赫兹光谱和成像技术在食品安全检测中的应用   总被引:6,自引:0,他引:6  
随着超快激光技术的快速发展以及人们对太赫兹辐射与物质作用机理的进一步认识,太赫兹辐射作为一项新的、快速发展的技术在很多领域受到广泛关注,在安全检测、医学诊断、无线通信和制药等诸多领域预示着广泛的应用前景。由于食品安全问题的重要性,食品安全的检测技术面临着巨大的机遇与挑战。太赫兹光谱与成像技术提供了一种新型的食品安全检测手段。相比于其他技术,THz技术具有高信噪比和动态范围宽等诸多特点, 能够同时获得样品在THz波段的时域信息与频域信息,以及对应的物质物理结构和化学成分等重要信息,在食品安全检测领域具有独特的优势。文章简要介绍了太赫兹波的概念、特点和技术手段,太赫兹辐射技术在食品安全领域的最新应用进展,并讨论了THz技术应用的限制因素, 展望了THz技术的应用前景。  相似文献   

12.
科学技术的发展对于磁场强度质量的要求越来越高,极端强磁场条件是人类追求的永远的科学目标,它孕育着许多重大的科学发现和新技术的产生,对人类的科学和技术以及生活产生重大的影响.以磁体为核心与电力电子器件以及相关的软件等结合可以构成各种各样科学仪器和装置,广泛应用在科学研究和工业特种装备中.磁技术对于人类的科学与技术进步起到越来越重要的作用,尤其是极高磁场所带来的诸多优点,使得人类对于物质世界认识不断加深,对于生命的起源以及从事疾病的防治的研究有特别重要的意义.本文介绍磁体基本原理、磁场产生的方法与应用以及相关的发展.  相似文献   

13.
非线性光学相位共轭及其在激光工程中的应用   总被引:2,自引:0,他引:2  
杜祥琬 《物理》1997,26(6):323-327
非线性光学相位共轭是现代光学一个有生命力的分支,文章简单介绍了它的原理和产生相位共轭波的几种基本途径,重点介绍了它在激光工程中的可能应用与进展,并指出有待研究解决的问题。  相似文献   

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We discussed some aspects of the tomographic-probability representation of quantum mechanics. Using known generic inequalities for Shannon and relative entropies, we obtain some new inequalities for special functions such as Laguerre, Legendre, and two-variable Hermite polynomials.  相似文献   

16.
Huang  Zan  Chen  Hsinchun  Yip  Alan  Ng  Gavin  Guo  Fei  Chen  Zhi-Kai  Roco  Mihail C. 《Journal of nanoparticle research》2003,5(3-4):333-363
Nanoscale science and engineering (NSE) and related areas have seen rapid growth in recent years. The speed and scope of development in the field have made it essential for researchers to be informed on the progress across different laboratories, companies, industries and countries. In this project, we experimented with several analysis and visualization techniques on NSE-related United States patent documents to support various knowledge tasks. This paper presents results on the basic analysis of nanotechnology patents between 1976 and 2002, content map analysis and citation network analysis. The data have been obtained on individual countries, institutions and technology fields. The top 10 countries with the largest number of nanotechnology patents are the United States, Japan, France, the United Kingdom, Taiwan, Korea, the Netherlands, Switzerland, Italy and Australia. The fastest growth in the last 5 years has been in chemical and pharmaceutical fields, followed by semiconductor devices. The results demonstrate potential of information-based discovery and visualization technologies to capture knowledge regarding nanotechnology performance, transfer of knowledge and trends of development through analyzing the patent documents.  相似文献   

17.
核探针的概念起源于电子探针,它综合了离子束分析技术的特点,已成为很有应用前景的分析工具.本文结合上海新建成的核探针,介绍它们的原理、结构和部分应用. In concept,the scanning nuclear microprobe is similar to the scanning electron micro-probe,but has much higher sensitivity for microanalysis.The main features and the construction of thenew-built Nuclear Microprobe in Shanghai are described.It has been proved to be an ideal tool for mi-croanalysis in the fields of medical and biology,metallurg,microelectronics,archaeology and earthsciences.Its potentiality is demonstrated with examples in the applications of these fields.  相似文献   

18.
THz关键技术及其在生物医学中的应用   总被引:3,自引:0,他引:3       下载免费PDF全文
THz电磁辐射的关键技术就是THz的产生和检测.本文分别介绍了两种产生THz辐射的方法及其对应的检测方法,较为全面地论述了THz成像技术,详细分析了THz成像技术的成像装置、成像原理及成像过程,并对其在生物医学方面的应用前景进行了重点分析.  相似文献   

19.
A brief review of some aspects of technology and applications of the sol-gel technology is presented. The content is divided into three parts concerning: (1) synthetic aspects of this technique, (2) optical sensors (optodes) and (3) pure and doped silica nanopowders manufactured by the sol-gel method. The versatility and applicability of the method is discussed. Also, several examples of active (”smart”) materials obtained by this technique are presented.  相似文献   

20.
Abstract

This review article describes some existing microplasma sources and their applications in analytical chemistry. These microplasmas mainly include direct current glow discharge (DC), microhollow-cathode discharge (MHCD) or microstructure electrode (MSE), dielectric barrier discharge (DBD), capacitively coupled microplasmas (CCμPs), miniature inductively coupled plasmas (mICPs), and microwave-induced plasmas (MIPs). The historical development and recent advances in these microplasma techniques are presented. Fundamental properties of the microplasmas, the unique features of the reduced size and volume, as well as the advantageous device structures for chemical analysis are discussed in detail, with the emphasis toward detection of gaseous samples. The analytical figures of merit obtained using these microplasmas as molecular/elemental-selective detectors for emission spectrometry and as ionization sources for mass spectrometry are also given in this review article.  相似文献   

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