Researching the extinction properties of noble metal nanoparticles via discrete dipole approximation

本文运用离散偶极近似理论(DDA)，计算球状、棒状与椭球状的贵金属(金、银)纳米粒子的消光光谱。首次系统地研究粒子的形状、尺寸、周围介质的介电系数及粒子的材料对贵金属纳米粒子消光性质的影响，并对形状的影响与介电常数的影响作出相应的理论解释。 利用Na3C6H5O7还原HAuCl4的方法，制得不同粒径的金纳米球，观测相应的UV/VIS吸收光谱，从实验上分析粒子的大小对UV/VIS吸收光谱的影响，并用DDA理论与Mie’s理论对该实验光谱进行模拟发现：用DDA计算的结果能相对准确地反映该实验光谱的峰位与变化趋势。并利用一步合成法制得银纳米球、银纳米棒与纳米线，粗略估计粒子的形状对UV/VIS吸收...In this dissertation, the Discrete Dipole Approximation (DDA) is used to calculate the extinction spectra of the noble metal (gold、silver) nanoparticles，which have the shapes of the sphere、ellipsoid and rod. For the first time, we systematically analyze the effects of the size、 shape、component and the dielectric property of the surrounding medium on the optical extinction spectra of noble metal (s...学位：理学硕士院系专业：物理与机电工程学院物理学系_光学学号：20002401

Design of Automatic System for Measuring Dielectric Properties of Microwave Dielectric Ceramics

开路型微波陶瓷材料介电性能自动测试系统的设计包括系统的测试原理、系统硬件和软件组成。利用操作界面友好的自动测试程序,可在程序面板上控制网络分析仪,实现测试数据的实时采集、分析计算与显示存储,从而提高测试效率与精度。实测表明,利用该系统能对高介电常数、低损耗的微波陶瓷材料复介电常数进行快速、准确、无损的自动测试。Design of open automatic system for measuring dielectric properties of Microwave Dielectric Ceramics(MWDC) is introduced,including testing principle,system hardware and software.The automatic measurement program provids a friendly interface between the VNA and the experiment operators,it can be applied to control the network analyzer,sample and compute the testing data,the results can be obtained and saved instantly.the measurement efficiency and precision are improved.It is shown that the system can be used for the rapid,accurate,nondestructive and automatic measurement of the high εr′ and low tan δ of MWDC materials

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目的 研究高危型人乳头瘤病毒（HR-HPV）感染相关的宫颈病变程度与抗人乳头瘤状病毒（HPV）抗体水平的相关性,探讨HPV致病的免疫学问题。方法 选取2012年1月-2013年6月在该院妇产科门诊就诊的女性中选取60例病理确诊为女性宫颈病变（CINⅠ及以上）,且宫颈脱落细胞的DNA检测为HR-HPV阳性者为研究组,根据组织学检测结果将研究组进一步分为低度病变组30例（CINⅠ）和高度病变组30例（CINⅡ或Ⅲ）。对照组为经核酸检测无HPV感染且病理诊断未见癌前病变的门诊患者60例,按年龄进一步分为低年龄组和高年龄组。低年龄组和高年龄组与低度病变组和高度病变组的年龄差异无统计学意义（P〉0.05）。分别抽取研究组及对照组外周血,检测其抗HR-HPV L1 Ig G抗体及中和抗体滴度,比较研究组与对照组抗体阳性率及抗体滴度水平的差别。结果 研究组血清中的抗HR-HPV L1 Ig G抗体阳性率及抗体滴度均高于对照组（P〈0.05）;低度病变组患者血清中的抗HR-HPV的中和抗体滴度高于相应对照组（P〈0.05）,而高度病变组的抗HR-HPV的中和抗体阳性率及抗体水平与相应对照组比较差异无统计学意义（P〉0.05）。结论 宫颈病变患者血清中抗HR-HPV L1 Ig G抗体升高,说明HPV感染可引起机体的体液免疫反应。低度病变组的中和抗体水平相对较高,可能是机体产生的中和抗体阻止了病毒的进一步感染。高度病变组的Ig G抗体和中和抗体均低下,说明进入CINⅡ/Ⅲ后HPV已经逃避了免疫系统的监视。基金项目：厦门市科技局项目（3502220124050）;2011年福建省科技计划项目资助计划,青年创新项目（20111）00310517

Gold Nanoparticles Application in Gene Mutation Detection and SNP Analysis

[中文文摘]对特异核苷酸序列的高选择性检测在生物医学研究和临床检测中日趋重要.纳米金特殊的光学性质、电学性质、化学性质、以及良好的生物相容性,使之成为检测生物大分子的首选工具.本文介绍了几种典型的基因突变检测及单核苷酸多态性(SNP)分析系统:基因芯片、生物传感器和光学检测系统.综述了多种颇有新意的检测方法和原理,详细阐明了它们的检测机制和研究进展,分析并比较了纳米金不同的作用方式,为纳米金在突变检测上的进一步研究提供了一定思路和参考.[英文文摘]Highly selective detection of specific oligonucleotide sequences is increasingly important in biomedical research and clinical diagnosis.The excellent optical,electrical,and chemical properties make gold nanoparticles(GNPs) unique tools for biomolecule detection.GNPs-based methods for the detection of gene mutation and single nucleotide polymorphism(SNP) are more selective,sensitive,and cost-efficient,compared to the conventional technologies,which require bulky and expensive instruments or involve time-cost procedures. This paper presents and demonstrates the principles and mechanisms of several typical GNPs-based methods for gene mutation and SNP analysis , aiming to provide some ideas and references for further studies.福建省青年科技人才创新项目(No.2006F3128)资助

A DDA Calculation on the Optical Properties of Silver Nanorods

【中文文摘】利用离散偶极近似 (Discretedipoleapproximation ,简称DDA)的方法 ,从理论上对粒子的形状、尺寸及周围介质等因素对银纳米粒子 ,特别是银纳米棒的光学性质的影响进行了较系统的研究 .计算表明 ,置于空气中的棒状银纳米粒子的光学性质与其形状密切相关 ,纵向表面等离子体共振吸收峰的位置随纳米棒长径比的增加呈现线性红移关系 .给出了空气中银纳米棒纵向表面等离子体共振吸收峰的位置随长径比变化的DDA拟合公式 .如果将金属纳米粒子置于折射率更高的介电环境中 ,其纵向等离子体共振吸收峰的位置进一步呈现线性红移关系 .合成的银纳米粒子的TEM图像及相关的UV VIS消光光谱显示DDA计算结果与实验值相当一致 .DDA算法与Mie′s理论在计算球状银纳米粒子的消光系数时给出很接近的结果 ,这表明用DDA的方法来分析银的光学性质是准确可靠的 ;而DDA算法对银纳米棒消光特性的成功拟合则表明 ,该算法相对Gans′理论而言 ,在研究纳米粒子的光学性质时具有更广的适用性及更高的准确性 . 【英文文摘】The optical properties of metal nanoparticles are quite different from those of the bulk materials mainly due to the collective oscillations of their conduction electrons known as the surface plasmon resonance (SPR), which is strongly dependent on the particle shape and size, and the dielectric properties of the local environment where the nanoparticles are embedded in. Based on the discrete dipole approximation (DDA) method, we studied the optical properties of silver nanorods with different aspect ratios ...Project supported by the National Natural Science Foundation of China (2 0 2 2 80 2 0,2 0 0 2 10 0 2

The Size and Shape Effects on the Optical Properties of Gold Nanoparticles

【中文文摘】纳米尺度的金属及半导体呈现出特殊的光学、电学及磁学性质,采用近年发展起来的离散偶极近似(DDA)的方法,我们分析了金纳米粒子的尺寸及形状对其光学性质的影响。粒子周围介质的影响在文中亦作了分析。计算结果显示,金纳米粒子的等离子体吸收带同时受到粒子尺寸和形状的影响,但来自形状的影响更为明显。与米氏理论及扩展的甘氏理论相比较,DDA方法在粒子尺寸不再远小于入射光波长的时候更准确,并能应用于任何形状的纳米粒子。理论计算与实验结果能较好的吻合。 【英文文摘】Metals and semiconductors exhibit unusual optical, electronic, and magnetic properties at the nanometer scale. Based on the newly developed method, discrete dipole approximation (DDA), the dependence of the optical properties of the gold nanoparticles on the size and shape was analyzed. The effects of the surrounding medium were also taken into consideration in the calculation. The calculated results show that the plasmon absorption band depends on both the size and shape of the gold noanoparticles. However , the influence of the shape is more significant . Compared to the Mieps theory and the extension , Gansp theory , the DDA method is more accurate when the dimensions of the particles are not much smaller than the wavelength of the incident light and can be applied to particles of any shape. The theoretical results are in good agreement with the experimental data.国家自然科学基金项目,批准号为 :20003008,2983306

导线张力对输电杆塔安全性和经济性的影响研究

针对使用广泛的500 kV架空输电线路，分别研究了在轻、中、重冰区，由断线及不均匀覆冰引起的导线张力对输电杆塔安全性和经济性的影响。研究表明：导线张力增加0～20%，若保持杆塔杆件规格不变，悬垂塔的超限杆件比例为0～51%，耐张塔的超限杆件比例为0～4%；若增大杆塔杆件规格以保证安全，悬垂塔的塔重增加0～28%，耐张塔的塔重增加0～5%；覆冰越厚，由断线引起的导线张力对杆塔影响越小，由不均匀覆冰引起的导线张力对杆塔影响越大；导线张力主要影响悬垂塔横担上、下平面交叉材、塔身主斜材等杆塔杆件。因此，对重要输电线路和输电线路重要区段，推荐重点加强悬垂塔的防串倒及抗冰能力。研究结论对工程实践具有一定的指导意义

Enhanced Cytotoxic Effects of Arenite in Combination with Active Bufadienolide Compounds against Human Glioblastoma Cell Line U-87

The cytotoxicity of a trivalent arsenic derivative (arsenite, AsIII) combined with arenobufagin or gamabufotalin was evaluated in human U-87 glioblastoma cells. Synergistic cytotoxicity with upregulated intracellular arsenic levels was observed, when treated with AsIII combined with arenobufagin instead of gamabufotalin. Apoptosis and the activation of caspase-9/-8/-3 were induced by AsIII and further strengthened by arenobufagin. The magnitude of increase in the activities of caspase-9/-3 was much greater than that of caspase-8, suggesting that the intrinsic pathway played a much more important role in the apoptosis. An increase in the number of necrotic cells, enhanced LDH leakage, and intensified G2/M phase arrest were observed. A remarkable increase in the expression level of γH2AX, a DNA damage marker, was induced by AsIII+arenobufagin. Concomitantly, the activation of autophagy was observed, suggesting that autophagic cell death associated with DNA damage was partially attributed to the cytotoxicity of AsIII+arenobufagin. Suppression of Notch signaling was confirmed in the combined regimen-treated cells, suggesting that inactivation of Jagged1/Notch signaling would probably contribute to the synergistic cytotoxic effect of AsIII+arenobufagin. Given that both AsIII and arenobufagin are capable of penetrating into the blood–brain barrier, our findings may provide fundamental insight into the clinical application of the combined regimen for glioblastoma.p.21 Article number: 6577 Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/)

A Journey into the City. Migrant Workers' Relation with the Urban Space and Struggle for Existence in Xu Zechen's Early Jingpiao Fiction

In contemporary China, rural-urban migrants constitute a new urban subject with entirely new identity-related issues. This study aims at demonstrating how literature can be a valid field in investigating such evolving subjectivities, through an analysis of Xu Zechen’s early novellas depicting migrants’ vicissitudes in Beijing. Combining a close reading of the texts and a review of the main social problems characterising rural-urban migration in China, this paper focuses on the representation of the identity crisis within the migrant self in Xu’s stories, taking into account the network of meanings employed by the writer to signify the objective and subjective tension between the city and the countryside