微波消解ICP-AES检测8种蜂蜜中常量、微量元素

用微波消解8种蜂蜜,以电感耦合等离子体发射光谱仪(ICP-AES)检测不同品种蜂蜜中Cu、Fe、Zn、Mn、Na、K、Ca、Mg、P等9种元素的含量,并优化微波处理样品条件。结果表明:不同品种蜂蜜中常量、微量元素含量不同。ICP-AES检测各元素的相对标准偏差在0.003%—4.84%之间,各元素回收率在93.26%—104.47%之间。采用微波消解技术和ICP-AES相结合检测常微量元素具有省时、省力、环境污染小,测定结果快速、准确等优点。     

电喷雾电离-串联质谱法测定纺织皮革产品中4,4-二氨基二苯醚

在不需要色谱分离的前提下,应用电喷雾电离-串联质谱法(ESI-MS/MS)对纺织品中偶氮染料还原产物4,4′-二氨基二苯醚进行测定。在MS/MS中,选择电喷雾离子源,以正离子扫描,选择离子监测模式和二级选择反应监测模式对4,4′-二氨基二苯醚进行定性和定量检测。以[M+H](m/z201)为母离子,选择其二级离子中碎片离子[M+H-NH3](m/z184)和[M+H-C6H7N](m/z108)为子离子。方法的检出限(19S/N)为70 ng.L-1。以1 ng.L-14,4′-二氨基二苯醚溶液进样2μL,平行测定9次,峰面积测定值的相对标准偏差为1.7%。     

红外光谱法测定感冒咳嗽颗粒中的蔗糖含量

以感冒咳嗽颗粒为原料,通过傅里叶变换红外光谱仪为检测手段,提出并建立一种简便、快速、不使用任何有机溶剂的蔗糖定量分析方法。准确称取蔗糖对照品,以铁氰化钾作为内标物,通过溴化钾压片制样,配制成标准系列,测定FT IR吸收光谱。选择蔗糖中不受干扰的特征吸收峰羰基峰和铁氰化钾中的特征吸收峰氰基峰,通过蔗糖特征峰吸光度与铁氰化钾特征峰的吸光度的峰高之比与其对应浓度进行线性回归分析,从而获得校准曲线。结果表明,方法的线性范围为0.04—34.56m g/g,其线性回归的相关系数r=0.9932,样品测定回收率为97.8%—101.6%,相对标准偏差小于5%。该方法准确,可靠,适合于其他蔗糖类物质的快速定量分析。     

理论物理研究与光纤通信新概念探索

文章从光纤通信的基本概念出发，介绍了新一代光纤通信系统———光孤子通信系统研究中与物理学有密切关系的一些方面，并结合作者近年来的探索性工作，较深入地讨论了这一首例非线性通信系统的关键问题，提出了孤子信道的ＲＬＬ（ｒｕｎｌｅｎｇｔｈｌｉｍｉｔｅｄ）编码和孤子－混沌通信的概念，并重点介绍了光孤子－呼吸子通信的基本思想和主要结果．     

复合量子密钥分发系统双速协议及其安全性分析

基于真空光速c是极限信号速度这一基本假设,提出了复合量子密钥分发(QKD)系统和双速协议,并证明双速协议的安全性与原BB84协议的安全性相同.结果表明,双速协议在将量子密钥生成效率从50%提高到100%的同时,还降低了窃听者Eve可能得到的信息量.双速协议由于打破了公开讨论之前Bob和Eve的对等地位,使QKD在概念上有了明显的改进,使协议基的选择空间有了本质性的扩充.具体给出了三个双速协议的实例,并详细分析了它们在截取重发攻击下的安全性 关键词： 量子密码 光纤量子密钥分发 双速协议     

Near-Field Enhancement and Absorption Properties of Metal-Dielectric-Metal Microcavities in the Mid-Infrared Range

An important property of optical metamaterials is the ability to concentrate light into extremely tiny volumes, so as to enhance their interaction with quantum objects. In this work, we numerically study the near-field en- hancement and absorption properties inside the cylindrical microcavities formed by a Au-GaAs-Au sandwiched structure. At normal incidence, the obtained reflection spectra show that the resonance wavelength of microcav- ities operates in the range of 5-5.S μm. We also calculate the contrast C （C = 1 - Rmln）, which can be increased to 97% by optimizing the structure＇s geometry parameters. Moreover, we demonstrate that the multilayer struc- ture with sub-wavelength electromagnetic confinement allows 10^3-10^4-fold enhancement of the electromagnetic energy density inside the cavities, which contains the most energy of the incident electromagnetic radiation and has a higher quality factor Q, indicating a narrower linewidth for surface enhanced molecular absorption spec- troscopy and the tracking of characteristic molecular vibrational modes in the mid-infrared region. The structure is insensitive to the polarization of the incident wave due to the symmetry of the cylindrical microcavities. The unique properties of the metal-dielectric-metal metamaterials will have potential applications in new plasmonic detectors, bio-sensing and solar cells, etc.     

Quantum election scheme based on anonymous quantum key distribution

An unconditionally secure authority-certified anonymous quantum key distribution scheme using conjugate coding is presented,based on which we construct a quantum election scheme without the help of an entanglement state.We show that this election scheme ensures the completeness,soundness,privacy,eligibility,unreusability,fairness,and verifiability of a large-scale election in which the administrator and counter are semi-honest.This election scheme can work even if there exist loss and errors in quantum channels.In addition,any irregularity in this scheme is sensible.     

Near field enhancement and absorption properties of the double cylindrical microcavities based on triple-band metamaterial absorber

We numerically study the near field enhancement and absorption properties inside the double cylindrical microcavities based on triple-band metamaterial absorber. The compact single unit cell consists of concentric gold rings each with a gold disk in the center, and a metallic ground plane separated by a dielectric layer. At the normal incidence of electromagnetic radiation, the obtained reflection spectra show that the resonance frequencies of the double microcavities are 16.65 THz,20.65 THz, and 25.65THz, respectively. We also calculate the values of contrast C(C = 1- Rmin), which can reach 95%,97%, and 95% at the corresponding frequencies by optimizing the geometry parameters of structure. Moreover, we demonstrate that the multilayer structure with subwavelength electromagnetic confinement allows 104～105-fold enhancement of the electromagnetic energy density inside the double cavities, which contains the most energy of the incoming electromagnetic radiation. Moreover, the proposed structure will be insensitive to the polarization of the incident wave due to the symmetry of the double cylindrical microcavities. The proposed optical metamaterial is a promising candidate as an absorbing element in scientific and technical applications because of its extreme confinement, multiband absorptions, and polarization insensitivity.     

多层金属纳米点阵的制备及其光学性质的研究

采用纳米球刻蚀法结合热蒸发技术制备了银和氧化硅交替层叠的纳米颗粒阵列. 扫描隧道显微镜测量结果表明, 该纳米阵列呈锥形多层结构. 分光光度计测量样品表明, 该纳米阵列在近红外波段存在明显的透射谷, 该透射谷来源于金属纳米颗粒局域等离激元的激发, 随着金属/介质层数的增多, 透射谷的位置向短波方向移动. 利用HFSS软件对该纳米阵列进行了仿真, 并分析了透射谷蓝移的原因. 关键词： 纳米球刻蚀技术 金属/介质纳米颗粒 表面等离子激元     

NH_3在Ir(211)和Ir(221)表面吸附的第一性原理计算

采用密度泛函理论,结合周期性平板模型,研究了NH_3在Ir(211)和Ir(221)表面上的吸附行为.计算结果显示,在Ir(211)、(221)两个面上,NH_3的优势吸附位皆为脊上的top位,吸附能均达到1.0 eV以上,都为化学吸附.电子结构计算结果表明,NH_3通过其N原子的2p_z轨道与底物金属Ir的5d_z~2轨道混合吸附于表面.